JP6142660B2 - Vehicle steering control device and vehicle steering control method - Google Patents

Description

  The present invention steers the steered wheel via an actuator such as a steered motor according to the steering operation of the steering wheel in a state where the torque transmission path between the steering wheel and the steered wheel is mechanically separated. The present invention relates to a vehicle steering control device and a vehicle steering control method.

  The SBW system described in Patent Document 1 does not include a sensor (such as a rotary encoder) that detects an actual turning angle of a steered wheel (in the following description, may be described as “actual turning angle”). The purpose is to calculate the turning angle of the steered wheels. For this reason, the sum of the absolute angle within the steering angle range of the steering wheel and the deviation between the absolute angle of the steered wheels detected over a plurality of periods and the steered angle range The difference from the initial value obtained by detecting the angle within a plurality of periods is obtained as an offset amount. Then, the sum of the steering absolute angle and the offset amount, which are detected over a plurality of cycles within the steering angle range of the steered wheels, is calculated as a relative steered wheel steer angle, and the steered wheels are steered. Calculate the corner.

JP 2011-005933 A

By the way, in the conventional SBW system including the technique described in Patent Document 1, the torque transmission path between the steering wheel and the steered wheel may be configured to include a universal joint. This is configured according to the layout of various components between the steering wheel and the steered wheels.
However, in the technique described in Patent Document 1, the relative turning angle of the steered wheels is determined without considering the change of the steering angle input by the steering wheel and transmitted by the universal joint in the torque transmission path. The turning angle of the steered wheels is calculated.
Therefore, a state occurs in which the relative turning angle of the steered wheels stored at the time when the ignition switch is turned off and the actual turning angle at the time when the ignition switch is turned on are different from each other in the SBW system. There is a problem that proper control becomes difficult.

  In order to solve the above-described problem, the present invention corrects the phase angle of the actual universal joint output angle calculation model set in advance with respect to the actual universal joint connecting the torque transmission paths in accordance with a preset increase / decrease threshold. Here, the phase angle of the actual universal joint output angle calculation model is corrected according to the increase / decrease threshold value so that the neutral position of the steering wheel approximates the neutral position of the steered wheel.

The phase angle of the actual universal joint output angle calculation model is corrected according to the increase / decrease threshold based on the actual universal joint output angle calculation model, the virtual universal joint output angle calculation model, and the steering angle of the steering wheel. Here, the virtual universal joint output angle calculation model is a model equation set in advance for a virtual universal joint that is arranged in series with the actual universal joint and virtually connects the torque transmission path together with the actual universal joint. is there.
In addition, the phase angle of the actual universal joint output angle calculation model can be corrected by comparing the actual steering angle maximum value with the input / output angle deviation for determining necessity of correction by correcting the phase angle of the actual universal joint output angle calculation model. If it is determined that correction using a corner is necessary, it is performed.
The actual turning angle maximum value is the maximum turning angle of the steered wheels when the steering angle input to the actual universal joint output angle calculation model is changed within a preset range. The correction input / output angle deviation is calculated by calculating the correction phase angle and the correction joint angle by comparing the actual turning angle maximum value and the virtual turning angle maximum value. Calculation is performed using the turning angle for determination, the steering angle, and the increase / decrease threshold calculated using the angle. The maximum virtual turning angle is the maximum value of the turning angle when the steering angle input to the virtual universal joint output angle calculation model and the actual universal joint output angle calculation model is changed within a preset range.

According to the present invention, it is possible to correct the phase angle of the actual universal joint output angle calculation model according to the turning angle calculated by inputting the steering angle to the actual universal joint and the virtual universal joint mounted on the vehicle. Become. This correction is performed so that the neutral position of the steering wheel approximates the neutral position of the steered wheel. Thereby, it becomes possible to estimate the phase difference of the rotation angle generated between the shafts connected using the universal joint.
For this reason, even if the steering angle changes while the ignition switch is in the OFF state, the turning angle can be calculated according to the phase difference of the rotation angle, and the estimation accuracy of the actual turning angle can be increased. As a result, the SBW system can be appropriately controlled.

1 is a diagram illustrating a schematic configuration of a vehicle including a vehicle steering control device according to a first embodiment of the present invention. 1 is a block diagram illustrating a schematic configuration of a vehicle steering control device according to a first embodiment of the present invention. FIG. It is a figure which shows the steering structure of a SBW system. It is a block diagram which shows the structure of a command calculating part. It is a block diagram which shows the process in which a clutch angle deviation calculation part calculates a clutch angle deviation. It is a figure which shows a waveform map. It is a block diagram which shows the process in which a turning angle calculation part calculates the turning angle of a steered wheel. It is a block diagram which shows the structure of a correction angle calculation block. It is a figure which shows a correlation map. It is a figure which shows a conversion map. It is a figure which shows the procedure which calculates the turning angle which changes according to a present steering angle. It is a figure which shows the procedure which calculates the actual machine input / output angle deviation which changes according to the present steering angle. It is a block diagram which shows the process in which a steering side clutch angle correction value calculation part calculates a steering side clutch angle correction value, and the process in which a clutch angle deviation correction value calculation part calculates a clutch angle deviation correction value. It is a figure which shows the process which a phase angle correction necessity determination part performs. It is a block diagram which shows the process which calculates the turning angle of a steered wheel based on the virtual steering angle changed within the range of +/- 180 [deg]. It is a figure which shows the relationship between the rotating shaft which a single universal joint has, and the rotational motion around a rotating shaft. It is a figure which shows the relationship between the axis | shaft of the input side in an universal joint, and the axis | shaft of an output side. It is a figure which shows the relationship between the axis | shaft of the input side in an universal joint, the axis | shaft of an output side, and a phase angle. It is a flowchart which shows the process performed before shipment of a vehicle. It is a flowchart which shows the process which calculates and memorize | stores a clutch angle deviation among the processes performed with respect to the vehicle after shipment. It is a flowchart which shows the process which calculates the steering angle of a steered wheel among the processes performed with respect to the vehicle after shipment, and the process which correct | amends the relationship between a steering angle and a steering motor rotation angle. It is a time chart which shows operation | movement of the vehicle using the steering control apparatus for vehicles of 1st embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
(Constitution)
FIG. 1 is a diagram illustrating a schematic configuration of a vehicle including a vehicle steering control device 1 according to the present embodiment. FIG. 2 is a block diagram showing a schematic configuration of the vehicle steering control device 1 of the present embodiment.
The vehicle provided with the vehicle steering control device 1 of the present embodiment is a vehicle to which the SBW system is applied. Here, the “SBW system” is an apparatus that forms a system called a steer-by-wire (SBW).
Here, in the SBW system, driving of an actuator (for example, a steered motor) is controlled in accordance with an operation of a steering wheel (steering wheel) that is steered by a driver of the vehicle, and the steered wheel is steered. Thus, the traveling direction of the vehicle is changed. For the drive control of the steering motor, the clutch that is interposed between the steering wheel and the steered wheel is switched to the open state, which is the normal state, and the torque transmission path between the steering wheel and the steered wheel is mechanically separated. Perform in the state.

And, for example, when an abnormality occurs in a part of the SBW system, such as disconnection, the clutch in the opened state is switched to the engaged state, and the torque transmission path is mechanically connected to Steering of the steered wheels is continued according to the operation state.
As shown in FIGS. 1 and 2, the vehicle steering control device 1 according to the present embodiment includes a steered motor 2, a steered motor control unit 4, a clutch 6, a reaction force motor 8, and a reaction force motor. A control unit 10 is provided.
The steered motor 2 is an electric motor that is driven in accordance with a steered motor drive current output from the steered motor control unit 4, and rotates according to a target steered angle according to an operation of the steering wheel, thereby turning steered wheels. A steering actuator for steering control is formed. The steered motor 2 outputs a steered torque for turning steered wheels by being driven according to the steered motor drive current. As the steering actuator, it is possible to use a power cylinder, a hydraulic circuit including a solenoid, or the like in addition to the electric motor.

The steered motor 2 has a rotatable steered motor output shaft 12.
A steered output gear 12 a formed using a pinion gear is provided on the tip side of the steered motor output shaft 12.
The steered output gear 12a meshes with a rack gear 18a provided between both ends of the rack shaft 18 inserted through the steering rack 14.
The steered motor 2 is provided with a steered motor angle sensor 16 and a steered motor torque sensor 2t.
The steered motor angle sensor 16 detects the steered motor rotational angle that is the rotational angle of the steered motor 2, and sends an information signal including the detected steered motor rotational angle via the steered motor control unit 4. Output to the reaction force motor control unit 10.

The steered motor torque sensor 2t detects a steered motor torque that is a torque generated by the steered motor 2 during driving. Then, the steered motor torque sensor 2t outputs an information signal including the detected steered motor torque to the reaction force motor control unit 10. In the following description, the steering motor torque may be described as “torque sensor value Vtm”. Further, the steering motor torque detected by the steering motor torque sensor 2t may be converted into steering torque.
In the present embodiment, the steering motor torque detected by the steering motor torque sensor 2t is converted into steering torque that is torque applied by the driver to the steering wheel 32. And the case where the information signal containing this converted steering torque is output to the reaction force motor control part 10 is demonstrated.
The steering rack 14 is formed in a cylindrical shape, and a rack shaft 18 that is displaced in the vehicle width direction according to the rotation of the steering motor output shaft 12, that is, the rotation of the steering output gear 12a is inserted therethrough.

In addition, two stopper portions 14 a that cover the outer diameter surface of the rack shaft 18 from the entire circumference are provided inside the steering rack 14. The two stopper portions 14a are respectively provided on the right side and the left side in the vehicle width direction of the steering output gear 12a inside the steering rack 14. In addition, in FIG. 1, illustration of the stopper part 14a provided in the vehicle width direction right side rather than the steering output gear 12a is abbreviate | omitted among the two stopper parts 14a.
Of the portion of the rack shaft 18 that is inserted into the steering rack 14 and disposed inside, the portions on the right and left sides in the vehicle width direction of the stopper portion 14a are opposed to each other in the axial direction of the stopper portion 14a and the rack shaft 18. An end abutting member 18b is provided. In FIG. 1, of the two end contact members 18b, illustration of the end contact member 18b provided on the right side in the vehicle width direction from the stopper portion 14a is omitted.

Both ends of the rack shaft 18 are connected to the steered wheels 24 via tie rods 20 and knuckle arms 22, respectively. A tire axial force sensor 26 is provided between the rack shaft 18 and the tie rod 20.
The tire axial force sensor 26 detects an axial force that acts in the axial direction (vehicle width direction) of the rack shaft 18, and this detected axial force (may be described as “tire axial force” in the following description). Is output to the reaction force motor control unit 10.

The steered wheels 24 are front wheels (left and right front wheels) of the vehicle. Change the direction of travel of the vehicle. In the present embodiment, a case where the steered wheels 24 are formed of left and right front wheels will be described. Accordingly, in FIG. 1, the steered wheel 24 formed with the left front wheel is denoted as steered wheel 24L, and the steered wheel 24 formed with the right front wheel is denoted as steered wheel 24R.
The steered motor control unit 4 inputs and outputs information signals through the reaction force motor control unit 10 and a communication line 28 such as a CAN (Controller Area Network).

The steered motor control unit 4 includes a steered position servo control unit 30 and a steered side previous process content storage unit MA.
The steered position servo control unit 30 calculates a steered motor drive current for driving the steered motor 2, and outputs the calculated steered motor drive current to the steered motor 2.
Here, the steering motor drive current controls the steering torque described above, calculates a target turning angle according to the operation of the steering wheel, and turns the steering motor 2 according to the calculated target turning angle. This is a current for driving control.
The calculation of the turning motor drive current is performed by calculating a turning motor current command output by the reaction force motor control unit 10 and a command value (hereinafter referred to as a turning motor actual current) energizing the turning motor 2. In the description, it may be described as “steering motor actual current command It”. Specifically, the steered motor current command is corrected using the steered motor actual current command It, and the steered motor drive current is calculated.

The steered position servo control unit 30 measures the steered motor actual current command It, and estimates the temperature Tt of the steered motor 2 based on the measured steered motor actual current command It. Then, an information signal including the estimated temperature Tt of the steered motor 2 is output to the reaction force motor control unit 10. This is to estimate overheating of the motors (the steered motor 2 and the reaction force motor 8) due to resistance heat generation due to current application.
The steered motor actual current command It is measured, for example, by incorporating a substrate temperature sensor (not shown) in the steered motor 2 and using the incorporated substrate temperature sensor.
Here, as a method of estimating the temperature Tt of the steered motor 2 based on the steered motor actual current command It, for example, in a large current range, the steered motor actual current command It is used using the measured actual current value. Ask for. Specifically, the measured actual current value is compared with the current threshold value stored in advance, and when the measured actual current value is larger than the current threshold value, the measured actual current value is converted into the steering motor. Adopted as actual current command It.

On the other hand, in the small current region, the actual motor current command It is estimated based on the rotational speed of the steered motor 2 using the motor NT characteristic that defines the relationship between the rotational speed of the steered motor 2 and the torque. Specifically, the actual current value measured is not adopted as the steering motor actual current command It, and the current value estimated based on the number of revolutions of the steering motor 2 using the motor NT characteristics is used as the actual steering motor actual value. Adopted as current command It.
Then, the temperature Tt of the steered motor 2 is estimated using the steered motor actual current command It adopted as described above.
In addition, the description regarding the steering side last process content storage part MA is mentioned later.

The clutch 6 is interposed between the steering wheel 32 and the steered wheel 24 operated by the driver, and is switched to an open state or an engaged state according to a clutch drive current output from the reaction force motor control unit 10. Note that the clutch 6 is in an open state in a normal state.
Here, when the state of the clutch 6 is switched to the released state, the torque transmission path between the steering wheel 32 and the steered wheel 24 is mechanically separated, and the steering operation of the steering wheel 32 is not transmitted to the steered wheel 24. And On the other hand, when the state of the clutch 6 is switched to the engaged state, the torque transmission path between the steering wheel 32 and the steered wheel 24 is mechanically coupled, and the steering operation of the steering wheel 32 is transmitted to the steered wheel 24. And

A steering angle sensor 34, a steering torque sensor 36, a reaction force motor 8, and a reaction force motor angle sensor 38 are disposed between the steering wheel 32 and the clutch 6.
The steering angle sensor 34 is provided, for example, in a steering column that rotatably supports the steering wheel 32.
The steering angle sensor 34 detects a current steering angle that is a current rotation angle (steering angle) of the steering wheel 32. Then, the steering angle sensor 34 outputs an information signal including the detected current steering angle of the steering wheel 32 to the reaction force motor control unit 10. In the following description, the current steering angle may be described as “current steering angle θH”.

Here, a vehicle in recent years is often equipped with a sensor that can detect the steering angle of the steering wheel 32 as a standard. For this reason, in this embodiment, the case where the sensor which can detect the steering angle of the steering wheel 32 which is an existing sensor in the vehicle is used as the steering angle sensor 34 will be described.
Similarly to the steering angle sensor 34, the steering torque sensor 36 is provided, for example, in a steering column that rotatably supports the steering wheel 32.

The steering torque sensor 36 detects a steering torque that is a torque applied by the driver to the steering wheel 32. Then, the steering torque sensor 36 outputs an information signal including the detected steering torque to the reaction force motor control unit 10. In the following description, the steering torque may be described as “torque sensor value Vts”.
The reaction force motor 8 and the reaction force motor angle sensor 38 will be described later.

The clutch 6 has a pair of clutch plates 40 that are separated from each other in the opened state and mesh with each other in the engaged state. In FIG. 1 and the following description, of the pair of clutch plates 40, the clutch plate 40 disposed on the steering wheel 32 side is referred to as “steering wheel side clutch plate 40a”, and the clutch plate disposed on the steered wheel 24 side. 40 is referred to as a “steered wheel side clutch plate 40b”.
The steering wheel side clutch plate 40 a is attached to a steering shaft 42 that rotates together with the steering wheel 32, and rotates together with the steering shaft 42.
The steered wheel side clutch plate 40 b is attached to one end of the pinion shaft 44 and rotates together with the pinion shaft 44.
The other end of the pinion shaft 44 is disposed in the pinion 46.

The pinion 46 incorporates a steering gear (not shown) that meshes with the rack gear 18a. In addition, the pinion 46 is provided with a pinion shaft torque sensor 46t.
The pinion shaft torque sensor 46 t detects pinion shaft torque that is torque applied to the pinion shaft 44. Then, the pinion shaft torque sensor 46 t outputs an information signal including the detected pinion shaft torque to the reaction force motor control unit 10. In the following description, the pinion shaft torque may be described as “torque sensor value Vtp”.
In the present embodiment, the pinion shaft torque detected by the pinion shaft torque sensor 46t is converted into steering torque that is torque applied by the driver to the steering wheel 32. And the case where the information signal containing this converted steering torque is output to the reaction force motor control part 10 is demonstrated.

The steering gear rotates together with the pinion shaft 44. That is, the steering gear rotates with the steered wheel side clutch plate 40 b via the pinion shaft 44.
The reaction force motor 8 is an electric motor that is driven according to a reaction force motor drive current output from the reaction force motor control unit 10, and forms a reaction force actuator that can output a steering reaction force to the steering wheel 32. Note that. The steering reaction force is output by rotating the steering shaft 42 that rotates together with the steering wheel 32. Here, the steering reaction force output from the reaction force motor 8 to the steering wheel 32 is calculated according to the tire axial force acting on the steered wheels 24 and the steering state of the steering wheel 32. This calculation is performed in a state where the clutch 6 is switched to the released state and the torque transmission path between the steering wheel 32 and the steered wheel 24 is mechanically separated. Thereby, an appropriate steering reaction force is transmitted to the driver who steers the steering wheel 32. That is, the steering reaction force output from the reaction force motor 8 to the steering wheel 32 is a reaction force acting in the direction opposite to the operation direction in which the driver steers the steering wheel 32. As the reaction force actuator, in addition to the electric motor, a power cylinder, a hydraulic circuit including a solenoid, or the like can be used.

The reaction force motor angle sensor 38 is a sensor provided in the reaction force motor 8.
The reaction force motor angle sensor 38 detects the rotation angle of the reaction force motor 8 and includes an information signal including the detected rotation angle (may be described as “reaction force motor rotation angle” in the following description). Is output to the reaction force motor control unit 10.
The reaction force motor control unit 10 inputs and outputs information signals via the steering motor control unit 4 and the communication line 28. In addition, the reaction force motor control unit 10 receives input of information signals output from the vehicle speed sensor 50 and the engine controller 52 via the communication line 28.

In addition, the reaction force motor control unit 10 drives and controls the reaction force motor 8 based on information signals received via the communication line 28 and information signals received from various sensors.
The vehicle speed sensor 50 is, for example, a known vehicle speed sensor, detects the vehicle speed of the vehicle, and outputs an information signal including the detected vehicle speed to the reaction force motor control unit 10.
The engine controller 52 (engine ECU) outputs an information signal including the state of the engine (not shown) (engine drive or engine stop) to the reaction force motor control unit 10.

In addition, the reaction force motor control unit 10 includes a command calculation unit 54, a reaction force servo control unit 56, a clutch control unit 58, and a reaction force side previous process content storage unit MB.
The command calculation unit 54 inputs information signals output from the vehicle speed sensor 50, the steering angle sensor 34, the engine controller 52, the steering torque sensor 36, the reaction force motor angle sensor 38, the tire axial force sensor 26, and the turning motor angle sensor 16. Receive.
The detailed configuration of the command calculation unit 54 will be described later.
The reaction force servo control unit 56 outputs a reaction force motor drive current for driving the reaction force motor 8 to the reaction force motor 8.

Further, the reaction force servo control unit 56 may describe the value of the current (reaction force motor actual current) that is actually energized to the reaction force motor 8 (in the following description, “reaction force motor current value Ih”). Measure).
Here, the calculation of the reaction force motor drive current is performed based on a reaction force motor current command (described later) output from the command calculation unit 54 and a reaction force motor current value Ih. Specifically, the reaction force motor current command is corrected using the reaction force motor current value Ih, and the reaction force motor drive current is calculated.

Further, the reaction force servo control unit 56 estimates the temperature Th of the reaction force motor 8 based on the measured reaction force motor current value Ih. The estimation of the temperature Th of the reaction force motor 8 is performed in the same procedure as the estimation of the temperature Tt of the turning motor 2 performed by the turning position servo control unit 30, for example.
Based on a clutch current command (described later) output from the command calculation unit 54, the clutch control unit 58 calculates a current necessary for switching the released clutch 6 to the engaged state as a clutch drive current. Then, the calculated clutch drive current is output to the clutch 6.
In addition, the description regarding the reaction force side last process content storage part MB is mentioned later.

Next, a detailed steering structure will be described with reference to FIGS. 1 and 2 and FIG.
FIG. 3 is a diagram showing a steering structure of the SBW system.
The steering wheel 32 is connected to one end of the steering shaft 42.
The steering shaft 42 is rotatably held by the steering column 5.
The other end of the steering shaft 42 is connected to one end of the steering side intermediate shaft 9 via the universal joint 7.
The steering column 5 is provided with a reaction force motor 8 connected to the steering shaft 42.
The reaction force motor 8 applies a reaction torque corresponding to the road surface reaction force transmitted from the steered wheel side toward the steering wheel according to the steered angle to the steering shaft 42. Thereby, even when the clutch 6 is disengaged, the driver can grasp the road surface reaction force according to the steered state.

The other end of the steering side intermediate shaft 9 is connected to one end of the clutch input shaft 13 via the universal joint 11.
The other end of the clutch input shaft 13 is concentrically opposed to one end of the clutch output shaft 17 via the clutch 6, and the clutch 6 disconnects (engages and disconnects) the clutch input shaft 13 and the clutch output shaft 17. Do.
The other end of the clutch output shaft 17 is connected to one end of the steered side intermediate shaft 21 via the universal joint 19.
The other end of the steered side intermediate shaft 21 is connected to one end of a pinion shaft 25 via a universal joint 23, and the other end of the pinion shaft 25 is connected to a rack and pinion type steering gear 27. In addition, although illustration is abbreviate | omitted, the both ends of the rack used as the output side of the steering gear 27 are each connected with the end of a right-and-left tie rod, and the other end of a tie rod is connected with the wheel.

  Therefore, when the clutch 6 is engaged, when the steering wheel 32 is rotated, the pinion 46 and the pinion shaft 25 are rotated. Here, the pinion 46 and the pinion shaft 25 rotate via the steering shaft 42, the steering side intermediate shaft 9, the clutch input shaft 13, the clutch output shaft 17, and the steered side intermediate shaft 21. The rotational movement of the pinion shaft 25 is a rack advance / retreat movement by the steering gear 27, and the wheels are steered by pushing and pulling the tie rods according to the rack advance / retreat.

  A reaction force motor 8 is connected to the steering shaft 42. When the reaction force motor 8 is driven in a state where the clutch 6 is disengaged, a reaction force torque is applied to the steering shaft 42. Therefore, the reaction force received from the road surface when the wheels are steered is detected or estimated, and the reaction force motor 8 is driven and controlled in accordance with the detected or estimated reaction force, so that the reaction force against the driver's steering operation is reduced. Power is granted.

  Usually, the steering motor 31 is driven and controlled while the clutch 6 is disengaged, and the reaction force motor 8 is driven and controlled to execute steer-by-wire, thereby obtaining desired steering characteristics and turning behavior characteristics. Realized and good operation feeling. On the other hand, when an abnormality occurs in the system, the steer-by-wire is stopped and the clutch 6 is returned to the engaged state as fail-safe to ensure mechanical backup.

The steering column 5 is supported on the vehicle body through a tilt pivot 41 so as to be swingable. The layout is such that the center position of the universal joint 7 between the steering shaft 42 and the steering side intermediate shaft 9 is different from the center position of the tilt pivot 41 when viewed from the side of the vehicle body.
The steering side intermediate shaft 9 and the steered side intermediate shaft 21 are each configured to be extendable and contractable in the axial direction.
The clutch 6 is fixed to the dash panel 45 via the bracket 43.

  As described above, the universal joint 7 and the universal joint 11 form a steering-side universal joint that mechanically connects the steering wheel 32 and the clutch 6. The universal joint 19 and the universal joint 23 form a steered-side universal joint that mechanically connects the steered wheel 24 and the clutch 6. That is, the torque transmission path includes a steering-side universal joint that mechanically connects the steering wheel 32 and the clutch 6, and a steering-side universal joint that mechanically connects the steered wheel 24 and the clutch 6. .

(Detailed configuration of the command calculation unit 54)
Next, the detailed configuration of the command calculation unit 54 will be described with reference to FIGS. 1 to 3 and FIG.
FIG. 4 is a block diagram illustrating a configuration of the command calculation unit 54.
As shown in FIG. 4, the command calculation unit 54 includes a neutral position storage unit 60, a steered motor current command calculation unit 62, and a clutch state switching unit 64. In addition, the command calculation unit 54 includes a steering side clutch angle calculation unit 66, a steering side clutch angle calculation unit 68, a clutch angle deviation calculation unit 70, a clutch angle deviation storage unit 72, and a turning angle storage unit. 74, a turning angle calculation unit 76, and a correction processing block 78.

  For example, the neutral position storage unit 60 sets both the steering angle of the steering wheel 32 and the actual turning angle of the steered wheels 24 at the neutral position: 0 [°] in the adjustment process performed at the time of manufacture of the vehicle or before shipment of the vehicle. The relationship between the steering angle and the turning motor rotation angle in the adjusted state is stored. The relationship between the steering angle and the turning motor rotation angle in a state where both the steering angle of the steering wheel 32 and the actual turning angle of the steered wheel 24 are adjusted to the neutral position is as follows. Deviation (deviation angle [deg]). In the present embodiment, as an example, the relationship between the steering angle and the turning motor rotation angle in a state where both the steering angle of the steering wheel 32 and the actual turning angle of the steered wheels 24 are adjusted to the neutral position is changed with respect to the steering angle. The case where the deviation of the rudder motor rotation angle is set to 0 [°] will be described.

  Further, the neutral position storage unit 60 corrects (overwrites) the relationship between the stored steering angle and the steered motor rotation angle in accordance with the steered angle of the steered wheel 24 calculated by the steered angle calculating unit 76. Process. For example, when the turning angle of the steered wheels 24 calculated by the turning angle calculation unit 76 is 10 [°] in the clockwise direction (the direction in which the vehicle turns to the right), this processing is performed by the turning motor for the steering angle. This is a process of correcting (overwriting) the rotation angle deviation counterclockwise to 10 [°].

The steered motor current command calculation unit 62 includes a relationship between the steering angle and the steered motor rotation angle stored in the neutral position storage unit 60, the current steering angle θH detected by the steering angle sensor 34, and the vehicle speed sensor 50. A steering motor current command is calculated based on the detected vehicle speed. Then, an information signal including the calculated turning motor current command is output to the turning position servo control unit 30.
The clutch state switching unit 64 receives an information signal including the state of the engine from the engine controller 52.

  The clutch state switching unit 64 determines that the ignition switch of the vehicle is on when the information signal including the engine state includes the engine drive state, and the clutch current for switching the clutch 6 to the open state. Generate directives. Then, an information signal including the generated clutch current command is output to the clutch angle deviation calculation unit 70, the clutch angle deviation storage unit 72, and the clutch control unit 58. The determination that the ignition switch of the vehicle is on is not limited to the case where the information signal including the engine state includes the engine driving state. In this case, when it is detected that the ignition switch has been operated by the driver or the like, it may be determined that the ignition switch of the vehicle is on even if the engine is stopped. The same applies to the following description. Further, even when the engine is stopped, the ignition switch of the vehicle is in the on state, for example, when the operation position of the ignition switch is ACC (accessory position).

  The clutch state switching unit 64 determines that the ignition switch of the vehicle is off when the information signal including the state of the engine includes a state of engine stop, and a clutch current for switching the clutch 6 to the connected state. Generate directives. Then, the information signal including the generated clutch current command is sent to the steering side clutch angle calculation unit 66, the steering side clutch angle calculation unit 68, the clutch angle deviation calculation unit 70, the clutch angle deviation storage unit 72, and the clutch control unit. Output to 58.

  The steering side clutch angle calculation unit 66 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition, the steering side clutch angle calculation unit 66 receives an information signal including the current steering angle of the steering wheel 32 from the steering angle sensor 34. Further, the steering side clutch angle calculation unit 66 receives an information signal including the torque sensor value Vts from the steering torque sensor 36.

Then, when the clutch 6 is switched to the connected state, the steering side clutch angle calculation unit 66 is based on the current steering angle θH detected by the steering angle sensor 34 and is the rotation angle on the steering wheel 32 side of the torque transmission path. Calculate the clutch angle. Further, an information signal including the calculated steering side clutch angle is output to the clutch angle deviation calculating unit 70.
Here, the steering side clutch angle calculation unit 66 of the present embodiment sets the current steering angle detected by the steering angle sensor 34 to the steering side output angle that is the rotation angle transmitted to the clutch 6 via the steering side universal joint. Based on this, the steering side clutch angle is calculated. The process in which the steering side clutch angle calculation unit 66 calculates the steering side clutch angle will be described later.

  The steered side clutch angle calculation unit 68 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition to this, the turning side clutch angle calculation unit 68 receives an input of an information signal including the turning motor rotation angle from the turning motor angle sensor 16. Further, the steered side clutch angle calculation unit 68 receives an input of an information signal including the torque sensor value Vts from the steering torque sensor 36.

And if the steering side clutch angle calculation part 68 switches the clutch 6 to a connection state, based on the steering motor rotation angle which the steering motor angle sensor 16 detected, the rotation angle in the steered wheel 24 side of a torque transmission path | route. The steered side clutch angle is calculated. Further, an information signal including the calculated steered side clutch angle is output to the clutch angle deviation calculating unit 70. The process in which the steered side clutch angle calculating unit 68 calculates the steered side clutch angle will be described later.
Here, the steered side clutch angle calculating unit 68 of the present embodiment is the rotational angle at which the steered motor rotation angle detected by the steered motor angle sensor 16 is transmitted to the clutch 6 via the steered side universal joint. A steering side clutch angle is calculated based on a certain turning side reverse output angle. The process in which the steering side clutch angle calculation unit 66 calculates the steering side clutch angle will be described later.

Further, the steered side clutch angle calculating unit 68 corrects parameters used in the process of calculating the steered side clutch angle according to the correction command value received from the correction processing block 78. The process performed by the steered side clutch angle calculation unit 68 according to the correction command value received from the correction process block 78 will be described later.
The clutch angle deviation calculating unit 70 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition, the clutch angle deviation calculating unit 70 receives an input of an information signal including the steering side clutch angle from the steering side clutch angle calculating unit 66. Further, the clutch angle deviation calculating unit 70 receives an input of an information signal including the steered side clutch angle from the steered side clutch angle calculating unit 68.

Then, the clutch angle deviation calculating unit 70 calculates a clutch angle deviation which is a deviation between the steering side clutch angle and the steered side clutch angle, and sends an information signal including the calculated clutch angle deviation to the clutch angle deviation storage unit 72. And it outputs to the turning angle calculation part 76. A specific process in which the clutch angle deviation calculating unit 70 calculates the clutch angle deviation will be described later.
The clutch angle deviation storage unit 72 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition, the clutch angle deviation storage unit 72 receives an information signal including the clutch angle deviation from the clutch angle deviation calculation unit 70.

And the clutch angle deviation memory | storage part 72 memorize | stores the clutch angle deviation at the time of switching the clutch 6 to a connection state.
The turning angle storage unit 74 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition, the turning angle storage unit 74 receives an input of an information signal including the turning motor rotation angle from the turning motor angle sensor 16.

And the turning angle memory | storage part 74 memorize | stores the turning angle of the steered wheel 24 when an ignition switch will be in an OFF state.
The turning angle calculation unit 76 receives an input of an information signal including a clutch current command from the clutch state switching unit 64. In addition, the turning angle calculation unit 76 receives an input of an information signal including the clutch angle deviation from the clutch angle deviation calculation unit 70. Further, the turning angle calculation unit 76 receives an input of an information signal including the torque sensor value Vts from the steering torque sensor 36.

Then, when the ignition switch is turned on, the turning angle calculation unit 76 determines the turning angle based on the clutch angle deviation calculated by the clutch angle deviation calculation unit 70 and the universal joint change angle before switching the clutch 6 to the released state. The turning angle of the steering wheel 24 is calculated. Further, an information signal including the calculated turning angle of the steered wheels 24 is output to the steered position servo control unit 30.
Here, the universal joint change angle is an angle calculated using a model stored in advance by the turning angle calculation unit 76 on the torque transmission path based on the current steering angle detected by the steering angle sensor 34. . The processing in which the turning angle calculation unit 76 calculates the turning angle of the steered wheels 24 and the model stored in the turning angle calculation unit 76 will be described later.

  Here, in the present embodiment, as an example, the structure of the turning angle calculation unit 76 is stored when the current steering angle detected by the steering angle sensor 34 does not change while the ignition switch is in the OFF state. The turning angle stored by the unit 74 is calculated as the turning angle of the steered wheels 24. The turning angle stored in the turning angle storage unit 74 is acquired from the turning angle storage unit 74 when the current steering angle detected by the steering angle sensor 34 does not change while the ignition switch is off. To do.

Further, the turning angle calculation unit 76 corrects the parameters used in the process of calculating the turning angle of the steered wheels 24 according to the correction command value received from the correction processing block 78. The processing performed by the turning angle calculation unit 76 according to the correction command value received from the correction processing block 78 will be described later.
The correction processing block 78, for example, a process performed in an adjustment process before shipping, a process performed in a maintenance factory or the like after the vehicle is shipped, etc. It is a processing block which performs the process corrected in. The configuration of the correction processing block 78 will be described later.

(Process in which the clutch angle deviation calculating unit 70 calculates the clutch angle deviation)
Hereinafter, a specific process in which the clutch angle deviation calculating unit 70 calculates the clutch angle deviation will be described with reference to FIGS. 1 to 4 and FIGS. 5 and 6.
FIG. 5 is a block diagram illustrating a process in which the clutch angle deviation calculation unit 70 calculates the clutch angle deviation.
In the process of calculating the clutch angle deviation, the steering side clutch angle calculation unit 66 calculates the steering side clutch angle θcl_in, and the steering side clutch angle calculation unit 68 calculates the steering side clutch angle θcl_out. Then, a value obtained by subtracting the steering clutch angle θcl_in from the steering clutch angle θcl_out is calculated as the clutch angle deviation dθCL (“dθCL = θcl_out−θcl_in” shown in FIG. 5).

Hereinafter, a process for calculating the steering side clutch angle θcl_in and a process for calculating the steering side clutch angle θcl_out will be specifically described.
The process in which the steering side clutch angle calculation unit 66 calculates the steering side clutch angle In the process in which the steering side clutch angle calculation unit 66 calculates the steering side clutch angle, first, the torque sensor value Vts received from the steering torque sensor 36. An information signal including Then, it is determined whether or not the torque sensor value Vts is within a preset steering-side clutch angle calculation torque threshold value range. Here, the steering-side clutch angle calculation torque threshold is set to a value that provides an appropriate torque for performing the process of calculating the steering-side clutch angle, and is stored in the steering-side clutch angle calculation unit 66. Therefore, if the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold, the steering torque applied by the driver to the steering wheel 32 is appropriate for performing processing for calculating the steering-side clutch angle. Torque.

When the torque sensor value Vts is determined to be within the range of the steering side clutch angle calculation torque threshold, the following processing is performed.
When the ignition switch is turned off, the current steering angle detected by the steering angle sensor 34 is input as the input angle tan θ _In of the universal joint 7 into the following equation (1), and the output angle θ _out of the universal joint 7 is calculated. . In addition, the following formula | equation (1) is a formula which shows a universal joint output angle calculation model which can be used as a model for calculating the output angle of each universal joint. The principle of establishing the universal joint output angle calculation model will be described later.
Here, the universal joint output angle calculation model is set in, for example, an adjustment process performed before shipment of the vehicle, and is stored in the steering clutch angle calculation unit 66 and the turning angle calculation unit 76.

Here, “α” shown in the above formula (1) is the universal joint (7, 11, 19) in a plan view on a preset plane (for example, a plane parallel to the vertical direction and the vehicle longitudinal direction). 23) is an angle formed by the input side axis and the output side axis.
Therefore, the universal joint output angle calculation model is a model formula indicating the relationship between the steered wheel side input angle and the steered wheel side output angle. Here, the steering wheel side input angle is an angle input from the steering wheel 32 side to the universal joint, and the steered wheel side output angle is an angle obtained by outputting the steering wheel side input angle to the steered wheel 24 side via the universal joint. It is.

That is, when calculating the output angle θ _out of the universal joint 7, “α” shown in the above equation (1) is the output of the universal joint 7 (steering shaft 42) and the output of the universal joint 7. This is the angle formed by the side shaft (steering side intermediate shaft 9). In the following description, the angle α formed by the steering shaft 42 and the steering side intermediate shaft 9 may be defined as the joint angle α of the universal joint 7 and may be described as “joint angle α ₁ ”.
Joint angle alpha _1, for example, the current steering angle .theta.H, using the waveform map generated in advance, is calculated in the adjustment process or the like performed before shipment of the vehicle, the steering-side clutch angle calculating section 66, calculates the steering clutch angle Stored in the unit 68 and the turning angle calculation unit 76. The calculation and storing of the joint angle alpha ₁ after shipment of the vehicle, for example, may be performed in the garages and the like.

Further, the calculation of the joint angle alpha ₁ is an actual turning angle of the current steering angle and the steered wheels 24 of the steering wheel 32, the corresponding state of being adjusted to an angle (e.g., the current steering angle and the actual turning angle to each other, Both are performed in the neutral position: adjusted to 0 [°].
Here, the waveform map is a map shown in FIG. 6, and is stored in the clutch angle deviation calculation unit 70, for example. FIG. 6 is a diagram showing a waveform map, which is a map defined by mathematical formulas and the like regardless of the specifications of the vehicle.

In FIG. 6, the horizontal axis represents the steering angle (denoted as “steering angle [deg]” in the figure), and the vertical axis represents the deviation between the angle of the pinion 46 (pinion angle) and the steering angle (see FIG. In the above, it is described as “deviation angle [deg]”).
Here, since each universal joint has inconstant velocity, the relationship between the steering angle and the pinion angle is constant except for the state where the steering angle is 0 [deg], for example, as shown in FIG. The relationship between the pinion angle and the steering angle changes depending on the steering angle.

When calculating the joint angle α1, for example, the steering angle of the steering wheel 32 is changed to change the deviation angle [deg] in the waveform map. In this case, by changing the steering angle detecting upper and lower limit values of the deviation angle [deg], based on these detected upper and lower limits, and it calculates the joint angle alpha _1.
In addition, “θ _offset ” shown in the above formula (1) indicates the twist angle of the output-side shaft with respect to the input-side shaft of each universal joint (7, 11, 19, 23) in the torque transmission path. The phase angle.
Therefore, the universal joint output angle calculation model is a model formula that indicates the relationship between the steered wheel side output angle and the angle obtained by adding the phase angle indicating the twist angle of the output shaft with respect to the input shaft of the universal joint to the steered wheel side input angle. .

Also, the universal joint output angle calculation model is the angle formed by adding the phase angle to the steered wheel side input angle, the steered wheel side output angle, and the angle between the universal joint input side axis and the output side axis in plan view. This is a model formula showing the relationship of a certain joint angle α.
That is, when calculating the phase angle θ _offset of the universal joint 7, “θ _offset ” shown in the above equation (1) is a phase angle indicating the twist angle of the steering-side intermediate shaft 9 with respect to the steering shaft 42. . In the following description, the phase angle indicating the twist angle of the steering-side intermediate shaft 9 with respect to the steering shaft 42 is defined as the phase angle θ _offset of the universal joint 7 and may be described as “phase angle θ _offset1 ”.

Since the phase angle θ _offset is a design item of the vehicle, for example, when the vehicle is manufactured, the phase angle θ _offset is stored in the steering side clutch angle calculation unit 66, the steering side clutch angle calculation unit 68, and the steering angle calculation unit 76. Note that the phase angle θ _offset may be detected and stored, for example, before shipment of the vehicle. Further, the detection and storage of the phase angle θ _offset may be performed, for example, at a maintenance shop after the vehicle is shipped.

When detecting the phase angle θ _offset , the current steering angle of the steering wheel 32 and the actual turning angle of the steered wheels 24 are adjusted to mutually corresponding angles (for example, the current steering angle and the actual turning angle). The angles are both adjusted to the neutral position: 0 [°].
Next, the output angle θ _out of the universal joint 7 calculated as described above is input to the above equation (1) as the input angle tan θ _In of the universal joint 11, and the output angle θ _out of the universal joint 11 is calculated. Then, the output angle θ _out of the universal joint 11 is calculated as the steering side clutch angle θcl_in.

Here, when calculating the output angle θ _out of the universal joint 11, “α” shown in the above equation (1) is the same as the input-side shaft (steering-side intermediate shaft 9) of the universal joint 11 and the universal joint. 11 is an angle formed by the output side shaft (clutch input shaft 13). In the following description, the angle α formed by the steering-side intermediate shaft 9 and the clutch input shaft 13 may be defined as the joint angle α of the universal joint 11 and described as “joint angle α ₂ ”.

When calculating the output angle θ _out of the universal joint 11, “θ _offset ” shown in the above equation (1) is the phase angle indicating the twist angle of the clutch input shaft 13 with respect to the steering side intermediate shaft 9. Become. In the following description, the phase angle indicating the twist angle of the clutch input shaft 13 with respect to the steering side intermediate shaft 9 is defined as the phase angle θ _offset of the universal joint 11 and may be described as “phase angle θ _offset2 ”. .
As described above, the steering side clutch angle calculation unit 66 inputs the current steering angle detected by the steering angle sensor 34 to a preset steering side universal joint output angle calculation model, and calculates the steering side clutch angle θcl_in.

Here, the steering-side universal joint output angle calculation model is the following two model formulas (E1, E2).
E1. A model equation E2. _{Where the} joint angle α ₁ is input as “α” and the phase angle θ _offset1 is input as “θ _offset ” in the above equation (1). The above formula (1), "alpha" and enter the joint angle alpha ₂ as "theta _offset" as inputs the phase angle theta _offset2 model equation

The process in which the steered side clutch angle calculating unit 68 calculates the steered side clutch angle In the process in which the steered side clutch angle calculating unit 68 calculates the steered side clutch angle, first, an input from the steering torque sensor 36 is received. The information signal including the torque sensor value Vts is referred to. Then, it is determined whether or not the torque sensor value Vts is within a preset turning threshold clutch angle calculation torque threshold. Here, the steering-side clutch angle calculation torque threshold is set to a value that provides an appropriate torque for performing the process of calculating the steering-side clutch angle, and is stored in the steering-side clutch angle calculation unit 68. Therefore, if the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold, the steering torque applied by the driver to the steering wheel 32 performs processing for calculating the steering-side clutch angle. Appropriate torque.

And if it determines with the torque sensor value Vts being within the range of the torque threshold value for steering side clutch angle calculation, the following processes will be performed.
The turning motor rotation angle at the time when the ignition switch is turned off is input to the following equation (2) as the reverse input angle tan θ _In of the universal joint 23, and the reverse output angle θ _out of the universal joint 23 is calculated. In addition, the following formula | equation (2) is a formula which shows a universal joint reverse output angle calculation model which can be used as a model for calculating the reverse output angle of each universal joint.
Here, the universal joint reverse output angle calculation model is set, for example, in an adjustment process performed before shipment of the vehicle, and is stored in the steered side clutch angle calculation unit 68.

Here, when calculating the reverse output angle θ _out of the universal joint 23, “α” shown in the above equation (2) is the axis on the input side of the universal joint 23 (the steered side intermediate shaft 21). This is the angle formed by the output side axis (pinion shaft 25) of the universal joint 23. In the following description, the angle α formed by the steered-side intermediate shaft 21 and the pinion shaft 25 may be defined as the joint angle α of the universal joint 23 and may be described as “joint angle α ₄ ”.

  Therefore, the universal joint reverse output angle calculation model is a model formula showing the relationship between the steered wheel side reverse input angle and the steered wheel side reverse output angle. Here, the steered wheel side reverse input angle is an angle input from the steered wheel 24 side to the steered side universal joint, and the steered wheel side reverse output angle is the steered wheel side reverse input angle via the steered side universal joint. Is output to the steering wheel 32 side.

Further, when calculating the reverse output angle θ _out of the universal joint 23, “θ _offset ” shown in the above equation (2) is a phase angle indicating a twist angle of the pinion shaft 25 with respect to the steered side intermediate shaft 21. It becomes. In the following description, the phase angle indicating the torsion angle of the pinion shaft 25 with respect to the steered side intermediate shaft 21 is defined as the phase angle θ _offset of the universal joint 23 and may be described as “phase angle θ _offset4 ”. .
Therefore, the universal joint reverse output angle calculation model is a model showing the relationship between the steered wheel side reverse output angle and the angle obtained by subtracting the phase angle indicating the torsion angle of the output shaft relative to the universal joint input shaft from the steered wheel side reverse input angle. It becomes an expression.

Next, the reverse output angle θ _out of the universal joint 23 calculated as described above is input as the reverse input angle tan θ _In of the universal joint 19 to the above equation (2), and the reverse output angle θ _out of the universal joint 19 is calculate. Then, the reverse output angle θ _out of the universal joint 19 is calculated as the steered side clutch angle θcl_out.
Here, when calculating the reverse output angle θ _out of the universal joint 19, “α” shown in the above equation (2) is the axis on the input side of the universal joint 19 and the axis on the output side of the universal joint 19. Is the angle formed by Here, the input side axis of the universal joint 19 is the clutch output shaft 17, and the output side axis of the universal joint 19 is the steered side intermediate shaft 21. In the following description, the angle α formed by the clutch output shaft 17 and the steered side intermediate shaft 21 may be defined as the joint angle α of the universal joint 19 and may be described as “joint angle α ₃ ”.

When calculating the reverse output angle θ _out of the universal joint 19, “θ _offset ” shown in the above equation (2) is a phase indicating the twist angle of the steered intermediate shaft 21 with respect to the clutch output shaft 17. It becomes a corner. In the following description, the phase angle indicating the twist angle of the steered-side intermediate shaft 21 relative to the clutch output shaft 17 is defined as the phase angle θ _offset of the universal joint 19 and may be described as “phase angle θ _offset3 ”. is there.

As described above, the turning side clutch angle calculation unit 68 inputs the turning motor rotation angle detected by the turning motor angle sensor 16 to the preset universal joint reverse output angle calculation model, and turns the turning side clutch angle θcl_out. Is calculated.
In the above description, the processing is performed using the equations (1) and (2), but the present invention is not limited to this. That is, for example, the processing may be performed using a map indicating the relationship between the current steering angle and the steering clutch angle θcl_in and a map indicating the relationship between the turning motor rotation angle and the steering clutch angle θcl_out.

(Process in which the turning angle calculation unit 76 calculates the turning angle of the steered wheels 24)
Hereinafter, a specific process in which the turning angle calculation unit 76 calculates the turning angle of the steered wheels 24 will be described with reference to FIGS. 1 to 6 and FIG. 7.
FIG. 7 is a block diagram illustrating a process in which the turning angle calculation unit 76 calculates the turning angle of the steered wheels 24.
In the process of calculating the turning angle of the steered wheels 24, first, an information signal including the torque sensor value Vts received from the steering torque sensor 36 is referred to. Then, it is determined whether or not the torque sensor value Vts is within a preset turning angle calculation torque threshold. Here, the turning angle calculation torque threshold is set to a value that provides an appropriate torque for performing the process of calculating the turning angle, and is stored in the turning angle calculation unit 76. Therefore, if the torque sensor value Vts is within the range of the turning angle calculation torque threshold, the steering torque applied by the driver to the steering wheel 32 is an appropriate torque for performing the process of calculating the turning angle. is there.

When it is determined that the torque sensor value Vts is within the range of the turning angle calculation torque threshold, the following processing is performed.
The current steering angle detected by the steering angle sensor 34 at the time when the ignition switch is turned on is input as the input angle tan θ _In of the universal joint 7 to the above equation (1). Thereby, the output angle θ _out of the universal joint 7 is calculated.

Next, the output angle θ _out of the universal joint 7 calculated as described above is input to the above equation (1) as the input angle tan θ _In of the universal joint 11, and the output angle θ _out of the universal joint 11 is calculated. Then, the output angle θ _out of the universal joint 11 is calculated as the steering side clutch angle θcl_in.
Here, in the process of calculating the turning angle of the steered wheels 24, the steering-side clutch angle θcl_in calculated as described above is added to the clutch angle deviation dθCL stored in the clutch angle deviation storage unit 72. As a result, the turning angle calculation turning-side clutch angle Pθcl_out is calculated (“Pθcl_out = θcl_in + dθCL” shown in FIG. 7). That is, the turning angle calculation unit 76 acquires information on the clutch angle deviation dθCL stored from the clutch angle deviation storage unit 72 when calculating the turning angle of the steered wheels 24.

Then, the turning angle calculation turning side clutch angle Pθcl_out calculated as described above is input to the above equation (1) as the input angle tan θ _In of the universal joint 19, and the output angle θ _out of the universal joint 19 is calculated. To do.
Next, the output angle θ _out of the universal joint 19 calculated as described above is input to the above equation (1) as the input angle tan θ _In of the universal joint 23, and the output angle θ _out of the universal joint 23 is calculated.
After calculating the output angle theta _out of the universal joint 23, the output angle theta _out of the universal joint 23 which is the calculated, subtracting the offset component of each universal joint (7,11,19,23). Thereby, the influence by the offset component of each universal joint (7, 11, 19, 23) is removed from the output angle θ _out of the universal joint 23, and the turning angle of the steered wheels 24 is calculated.

Here, the offset component of each universal joint (7, 11, 19, 23) is expressed by the following equation (3). In addition, the following formula | equation (3) is a formula which shows a universal joint offset component calculation model which can be used as a model for calculating the offset component of each universal joint. The principle of establishing the universal joint offset component calculation model will be described later.
Here, the universal joint offset component calculation model is set, for example, in an adjustment process performed before shipment of the vehicle, and is stored in the turning angle calculation unit 76.

Therefore, the universal joint offset component calculation model is a model formula indicating a phase angle indicating a twist angle of the output shaft with respect to the input shaft of each universal joint (7, 11, 19, 23).
In addition to this, in the process of calculating the turning angle of the steered wheels 24, the output angle θ _out of the universal joint 23 obtained by dividing the offset component of each universal joint (7, 11, 19, 23) is used as the torque sensor value described above. Correction is performed based on Vtp.
Here, to correct the output angle θ _out of the universal joint 23, the torsion angles of the shafts and the universal joints (7, 11, 19, 23) based on the torque sensor value Vtp are used. The shafts are the steering shaft 42, the steering side intermediate shaft 9, the clutch output shaft 17, the steered side intermediate shaft 21, and the pinion shaft 25.

Moreover, the torsion angle of each shaft and each universal joint is represented by the following formula (4). The following equation (4) is a torque sensor model that can be used as a model for correcting the twist angle of each shaft and each universal joint when calculating the steered angle of the steered wheels 24. It is a formula which shows.
Torsion angle = torque sensor value Vtp [Nm] / torsional rigidity [Nm / rad] of each shaft and each universal joint (4)
Therefore, the torque sensor model is a model showing the relationship between the steering torque based on the pinion shaft torque detected by the pinion shaft torque sensor 46t, the torsional rigidity of each universal joint, and the torsional rigidity of the input shaft and output shaft of each universal joint. It becomes an expression.

Here, the torque sensor model is set, for example, in an adjustment process performed before the vehicle is shipped, and is stored in the turning angle calculation unit 76.
In the present embodiment, as an example, when the output angle θ _out of the universal joint 23 is corrected using the twist angle of each shaft and each universal joint, the twist angle is added to the output angle θ _out of the universal joint 23. The case where it does is demonstrated.
Thus, the turning angle calculation unit 76 calculates the turning angle of the steered wheels 24 based on the change angle at which the turning angle calculation turning-side clutch angle Pθcl_out has changed via the turning-side universal joint.

In addition, the turning angle calculation unit 76 of the present embodiment is configured based on a value obtained by inputting the turning angle calculation turning-side clutch angle Pθcl_out to a turning-side universal joint output angle calculation model set in advance. Calculate the turning angle.
Here, the turning-side universal joint output angle calculation model is the following two model formulas (E3, E4).
E3. The above formula (1), enter the joint angle alpha ₃ as "alpha", "theta _offset" as model inputs the phase angle theta _OFFSET3 expression E4. The above formula (1), enter the joint angle alpha ₄ as "alpha", "theta _offset" model equation thus entered a phase angle theta _OFFSET4 as a steering-side universal joint output angle calculation model, steered side Universal The joint output angle calculation model is a model formula based on the universal joint output angle calculation model shown by the above formula (1).

Further, the turning angle calculation unit 76 of the present embodiment subtracts the offset component of each universal joint from the change angle at which the turning angle calculation turning-side clutch angle Pθcl_out has changed via the turning-side universal joint. Based on this, the turning angle of the steered wheels 24 is calculated.
In addition, the turning angle calculation unit 76 of the present embodiment calculates the change angle at which the turning angle calculation turning-side clutch angle Pθcl_out has changed via the turning-side universal joint using the torque sensor model. Correct using the twist angle of the path. And based on this corrected value, the turning angle of the steered wheels 24 is calculated.

(Configuration of the correction angle calculation block 78)
Hereinafter, the configuration of the correction angle calculation block 78 will be described with reference to FIGS. 1 to 7 and FIGS. 8 to 15. FIG.
FIG. 8 is a block diagram showing a configuration of the correction angle calculation block 78.
As shown in FIG. 8, the correction angle calculation block 78 includes a correlation map storage unit 80, a conversion map storage unit 82, an actual machine input / output angle deviation calculation unit 84, a correction joint angle calculation unit 86, and a correction purpose. A phase angle calculation unit 88 is provided. In addition, the correction angle calculation block 78 includes a turning side clutch angle correction value calculation unit 90, a clutch angle deviation correction value calculation unit 92, a phase angle correction necessity determination unit 94, and a correction command value output unit 96. Prepare.

The correlation map storage unit 80 stores a correlation map generated when the vehicle is manufactured.
Here, as shown in FIG. 9, the correlation map includes a joint angle αd of a virtual universal joint (which may be described as “virtual universal joint” in the following description) used for calculation, and a calculation. It is a map which shows the relationship with the virtual input / output angle deviation to be used. FIG. 9 is a diagram showing a correlation map, which is a map defined by mathematical formulas and the like regardless of the specifications of the vehicle.
Here, the virtual universal joint is a universal joint that is arranged in series with the actual universal joint and virtually connects the torque transmission path with the actual universal joint.

In FIG. 9, the horizontal axis indicates the virtual steering angle θHd (denoted as “θHd” in the figure) that is the virtual steering angle, and the vertical axis indicates the virtual input / output angle deviation (in the figure, “θ _out d−θHd ”). Further, in FIG. 9, the maximum value of the virtual input / output angle deviation (denoted as “max” in the figure) and the minimum value of the virtual input / output angle deviation (denoted as “min” in the figure). The virtual input / output angle deviation maximum change width, which is the change width, is indicated as “PPd”.

At this time, the virtual steering angle θHd is changed within a range of −180 [deg] to +180 [deg], and input to the universal joint output angle calculation model used for generating the correlation map, and the output of the virtual universal joint is output. The angle θ _out d is calculated. Further, the virtual steering angle θHd is subtracted from the output angle θ _out d of the virtual universal joint to calculate a virtual input / output angle deviation. Further, when calculating the output angle θ _out d of the virtual universal joint, the offset component is removed.
Note that the universal joint output angle calculation model used to generate the correlation map is the same model expression as the universal joint output angle calculation model shown by the above expression (1).

Further, the joint angle α changed within the range of 0 to 90 [deg] is input as the joint angle αd of the virtual universal joint to the universal joint output angle calculation model used for generating the correlation map.
As shown in FIG. 9, the correlation map generated by the above processing is a map showing a relationship in which the amount of change in the virtual input / output angle deviation corresponding to the change in the virtual steering angle θHd increases as the joint angle αd increases. Become.
The conversion map storage unit 82 stores a conversion map generated when the vehicle is manufactured.
Here, as shown in FIG. 10, the conversion map is a map showing the relationship between the maximum change width difference value and the correction joint angle that is the correction joint angle used in the processing performed by the correction angle calculation block 78. is there. FIG. 10 is a diagram showing a conversion map, which is a map defined by mathematical formulas and the like regardless of the specifications of the vehicle.

In FIG. 10, the horizontal axis indicates the maximum change width difference value, and the vertical axis indicates the correction joint angle.
Here, the maximum change width difference value is a difference value between the virtual input / output angle deviation maximum change width described above and the actual machine input / output angle deviation maximum change width calculated by the actual machine input / output angle deviation calculation unit 84.
Further, as shown in FIG. 10, the conversion map is a map showing a relationship in which the correction joint angle increases as the maximum change width difference value increases.

The actual machine input / output angle deviation calculation unit 84 uses the actual vehicle and changes the steering angle from the output angle θ _out of the universal joint to the current steering angle in a state where the steering angle is changed within the range of −180 [deg] to +180 [deg]. Subtract θH to calculate the maximum change width of the actual input / output angle deviation.
Specifically, for example, in a maintenance shop or the like, the vehicle is in a state in which the steering angle of the steering wheel 32, the torque transmission path, and the actual turning angle of the steered wheels 24 are all adjusted to the neutral position. This state is a complete fastening state. When an information signal including a command value for starting processing performed by the actual machine input / output angle deviation calculation unit 84 is received, the steering angle is changed from −180 [deg] to +180 [deg] by operating the steering wheel 32 by a person or the like. ] Within the range.

Further, the turning angle calculation unit 76 calculates the turning angle according to the steering angle changed within the range of −180 [deg] to +180 [deg], and the current steering angle θH is calculated from the calculated turning angle. The value obtained by subtracting is detected.
Here, in this embodiment, as shown in FIG. 11, as an example, a case will be described in which the turning angle that changes in accordance with the current steering angle θH is calculated in the following order. In addition, FIG. 11 is a figure which shows the procedure which calculates the turning angle which changes according to present steering angle (theta) H. In FIG. 11, the horizontal axis indicates the current steering angle θH (denoted as “θH” in the figure), and the vertical axis indicates the turning angle calculated by the turning angle calculation unit 76 (in the figure, “ Described as “steering angle”).

First, as shown by an arrow S1 in FIG. 11, in a state where the steering angle is increased from 0 [deg] to +180 [deg], a turning angle that changes in accordance with the current steering angle θH is calculated.
Next, as indicated by an arrow S2 in FIG. 11, in a state where the steering angle is decreased from +180 [deg] to 0 [deg], a turning angle that changes in accordance with the current steering angle θH is calculated.
Then, as shown by an arrow S3 in FIG. 11, in a state where the steering angle is decreased from 0 [deg] to −180 [deg], a turning angle that changes in accordance with the current steering angle θH is calculated.

Finally, as shown by an arrow S4 in FIG. 11, in a state where the steering angle is increased from −180 [deg] to 0 [deg], a turning angle that changes according to the current steering angle θH is calculated.
When calculating the turning angle in the above order, as shown in FIG. 12, from the change in the actual machine input / output angle deviation obtained by subtracting the current steering angle θH from the calculated turning angle, the average of the maximum value and the minimum value The average of is calculated. Then, the change width between the average of the calculated maximum value and the average of the minimum value is calculated as the actual input / output angle deviation maximum change width.

FIG. 12 is a diagram illustrating a procedure for calculating an actual machine input / output angle deviation that changes in accordance with the current steering angle θH. In FIG. 12, the horizontal axis indicates the current steering angle θH (denoted as “θH” in the figure), and the vertical axis indicates the actual machine input / output angle deviation. In FIG. 12, the average of the maximum value of the actual machine input / output angle deviation is indicated as “max_ave”, and the average of the minimum value of the actual machine input / output angle deviation is indicated as “min_ave”. In addition to this, in FIG. 12, the actual machine input / output angle deviation maximum change width, which is the change width between max_ave and min_ave, is indicated as “PPr”. In FIG. 12, the actual machine input / output angle deviation that changes as the steering angle increases is indicated by a solid line, and the actual machine input / output angle deviation that changes as the steering angle decreases is indicated by a broken line.
That is, in the present embodiment, the current steering angle θH input to the universal joint output angle calculation model is changed within a preset range (± 180 [deg]) with reference to the neutral position (0 [deg]). Later, return to the neutral position. Then, based on the change width based on the maximum value and the minimum value of the turning angle at this time, the actual input / output angle deviation maximum change width PPr is calculated.

  In the present embodiment, the current steering angle θH input to the universal joint output angle calculation model is changed to the upper limit value (+180 [deg]) of a preset range with the neutral position (0 [deg]) as a reference. Then return to the neutral position. Furthermore, based on the change range based on the maximum value and the minimum value of the turning angle when returning to the neutral position after changing to the lower limit (−180 [deg]) of the preset range, the actual input / output angle The deviation maximum change width PPr is calculated.

  The correction joint angle calculation unit 86 calculates the actual input / output angle deviation maximum change width PPr and the virtual input / output angle deviation maximum change width PPd calculated using the correlation map stored in the correlation map storage unit 80. The difference (| PPr−PPd |) is calculated. Here, the virtual input / output angle deviation maximum change width PPd used in the processing of the correction joint angle calculation unit 86 is the actual input / output angle within the range of 0 to 90 [deg] as the joint angle αd of the virtual universal joint. A joint angle corresponding to the deviation maximum change width PPr is used.

Next, the correction joint angle calculation unit 86 inputs the maximum change width difference value, which is the calculated difference | PPr−PPd |, into the conversion map stored in the conversion map storage unit 82 and corrects the correction joint angle. Is calculated. In the following description, the correction joint angle may be described as “α _D ”.
The correction phase angle calculation unit 88 compares the actual machine input / output angle deviation maximum change width PPr with the virtual input / output angle deviation maximum change width PPd calculated using the correlation map. Here, the virtual input / output angle deviation maximum change width PPd used in the processing of the correction phase angle calculation unit 88 is the actual input / output angle within the range of 0 to 90 [deg] as the joint angle αd of the virtual universal joint. A joint angle corresponding to the deviation maximum change width PPr is used.

When the actual machine input / output angle deviation maximum change width PPr exceeds the virtual input / output angle deviation maximum change width PPd (PPr> PPd), the correction phase angle calculation unit 88 sets the correction phase angle to “0 [deg]. ] ". On the other hand, when the actual input / output angle deviation maximum change width PPr is less than the virtual input / output angle deviation maximum change width PPd (PPr <PPd), the correction phase angle calculation unit 88 sets the correction phase angle to “−90 [deg. ] ".
Here, the correction phase angle is a correction phase angle used in processing performed by the correction angle calculation block 78. In the following description, the correction phase angle may be described as “θ _offsetD ”.

The turning-side clutch angle correction value calculation unit 90 calculates a turning-side clutch angle correction value that is a turning-side clutch angle using the correction joint angle and the correction phase angle. The process in which the steered side clutch angle correction value calculation unit 90 calculates the steered side clutch angle correction value will be described later.
The clutch angle deviation correction value calculation unit 92 calculates a clutch angle deviation correction value that is a deviation between the steering side clutch angle correction value and the above-described steering side clutch angle.
Here, referring to FIG. 5 and using FIG. 13, the steering-side clutch angle correction value calculation unit 90 calculates the steering-side clutch angle correction value, and the clutch angle deviation correction value calculation unit 92 Processing for calculating the angular deviation correction value will be described.

FIG. 13 is a block diagram illustrating a process in which the steered side clutch angle correction value calculating unit 90 calculates a steered side clutch angle correction value, and a process in which the clutch angle deviation correction value calculating unit 92 calculates a clutch angle deviation correction value. It is.
In the process of calculating the clutch angle deviation correction value, the steering side clutch angle calculation unit 66 calculates the steering side clutch angle θcl_in, and the steering side clutch angle correction value calculation unit 90 calculates the steering side clutch angle correction value θcl_outD. . Then, a value obtained by subtracting the steering clutch angle θcl_in from the steering clutch angle correction value θcl_outD is calculated as a clutch angle deviation correction value dθCLD (“dθCLD = θcl_outD−θcl_in” shown in FIG. 13).
That is, in the present embodiment, the virtual universal joint UJD is arranged closer to the steered wheel 24 than the universal joint 23 in the process in which the steered side clutch angle correction value calculation unit 90 calculates the steered side clutch angle correction value.

Hereinafter, the process of calculating the steering side clutch angle correction value θcl_outD will be specifically described. Note that the process for calculating the steering side clutch angle θcl_in is the same as the process described above, and a description thereof will be omitted. Further, the process of calculating the turning-side clutch angle correction value θcl_outD is performed when it is determined that the torque sensor value Vts is within the range of the turning-side clutch angle calculation torque threshold.
First, a steering motor rotation angle at the time when the ignition switch is turned off, and inputs the above formula (2) as the reverse input angle tan .theta _{an In} virtual universal joint UJD, the reverse output angle theta _out of the universal joint UJD calculate.

Here, when calculating the reverse output angle θ _out of the universal joint UJD, the correction joint angle α _D calculated by the correction joint angle calculation unit 86 is used as “α” shown in the above equation (2). Use. In addition, the correction phase angle θ _offsetD (0 [deg] or −90 [deg]) calculated by the correction phase angle calculation unit 88 is used as “θ _offset ” shown in the above equation (2).
That is, the model equation using the correction joint angle α _D as “α” and the correction phase angle θ _offsetD as “θ _offset ” shown in the above equation (2) shown in FIG. Corresponds to the joint reverse output angle calculation model.

Next, the reverse output angle θ _out of the universal joint UJD calculated as described above is input to the above equation (2) as the reverse input angle tan θ _In of the universal joint 23, and the reverse output angle θ _out of the universal joint 23 is calculate. Further, the calculated reverse output angle θ _out of the universal joint 23 is input to the above formula (2) as the reverse input angle tan θ _In of the universal joint 19 to calculate the reverse output angle θ _out of the universal joint 19. Then, the reverse output angle θ _out of the universal joint 19 is calculated as a steered side clutch angle correction value θcl_outD.

That is shown in FIG. 13, using a joint angle alpha ₄ as "alpha" shown in the above formula (2), the model equation using phase angle theta _OFFSET4 as "theta _offset" is actual universal joint reverse output angle Corresponds to the calculation model. Similarly, using the joint angle alpha ₃ as "alpha" shown in the above formula (2), the model equation using phase angle theta _OFFSET3 as "theta _offset" corresponds to the actual universal joint reverse output angle calculation model .

By the above, the steering-side clutch angle correction value calculating section 90, the actual universal joint reverse output angle calculation model that has been set in advance, and the steered motor rotation angle, computed correction joint angle alpha _D correction phase angle theta _OffsetD Enter. Thereby, the steered side clutch angle correction value calculation unit 90 calculates the steered side clutch angle correction value θcl_outD.
The phase angle correction necessity determination unit 94 performs the processing described below, and determines whether or not the phase angle correction using the correction phase angle calculated by the correction phase angle calculation unit 88 is necessary.

First, by using the virtual steering angle θHd changed within the range of −180 [deg] to +180 [deg], the correction joint angle and the correction phase angle, and the clutch angle deviation correction value, the steered wheels 24 are used. Calculate the turning angle. The process of calculating the turning angle by changing the virtual steering angle θHd within the range of −180 [deg] to +180 [deg] will be described later.
Then, the current steering angle θH is subtracted from the calculated turning angle to calculate the reference correction necessity determination input / output angle deviation as shown in FIG. FIG. 14 is a diagram illustrating processing performed by the phase angle correction necessity determination unit 94. Further, in FIG. 14, the reference correction necessity determination input / output angle deviation is indicated by a solid line L1. In FIG. 14, the horizontal axis indicates the virtual steering angle θHd, and the vertical axis indicates the reference correction necessity determination input / output angle deviation.

Further, an addition correction necessity determination input / output angle deviation is calculated by adding a preset increase / decrease threshold to the virtual steering angle θHd with respect to the reference correction necessity determination input / output angle deviation. In addition, a subtraction correction necessity determination input / output angle deviation is calculated by subtracting a preset increase / decrease threshold in terms of the virtual steering angle θHd from the reference correction necessity determination input / output angle deviation.
Here, in this embodiment, a case where the increase / decrease threshold is set to 5 [deg] in terms of the virtual steering angle θHd will be described as an example. Note that the increase / decrease threshold is a value that can be appropriately set according to, for example, vehicle specifications.

In FIG. 14, the input / output angle deviation for determining whether or not addition correction is necessary is indicated by a broken line L2, and the input / output angle deviation for determining whether or not subtraction correction is required is indicated by a one-point difference line L3. Further, in FIG. 14, the maximum value of the addition correction necessity determination input / output angle deviation L2 is indicated as “maxL2”, and the maximum value of the subtraction correction necessity determination input / output angle deviation L3 is indicated as “maxL3”.
Here, as shown in FIG. 14, the reference correction necessity determination input / output angle deviation, the addition correction necessity determination input / output angle deviation, and the subtraction correction necessity determination input / output angle deviation are the maximum value and the minimum value. The change width is the same.

Next, the phase angle correction necessity determination unit 94 includes a maximum value maxL2 of the addition correction necessity determination input / output angle deviation L2, a maximum value maxL3 of the subtraction correction necessity determination input / output angle deviation L3, and the actual machine input / output. The maximum value of the actual input / output angular deviation maximum change width calculated by the angular deviation calculation unit 84 is compared.
When the maximum value of the maximum change width of the actual machine input / output angle deviation calculated by the actual machine input / output angle deviation calculation unit 84 is a value between the maximum value maxL2 and the maximum value maxL3, the correction phase angle calculation unit 88 is used. It is determined that the correction of the phase angle using the correction phase angle calculated by is unnecessary.

On the other hand, when the maximum value of the actual machine input / output angle deviation maximum change width calculated by the actual machine input / output angle deviation calculation unit 84 is not a value between the maximum value maxL2 and the maximum value maxL3, the correction phase angle calculation unit 88 is used. It is determined that it is necessary to correct the phase angle using the correction phase angle calculated by.
Here, referring to FIG. 7, using FIG. 15, the virtual steering angle θHd changed within the range of ± 180 [deg], the correction joint angle and the correction phase angle, and the clutch angle deviation correction value The process which calculates the turning angle of the steered wheel 24 is demonstrated using FIG. The following processing is performed when it is determined that the torque sensor value Vts is within the range of the turning angle calculation torque threshold.
FIG. 15 is a block diagram showing processing for calculating the turning angle of the steered wheels 24 based on the virtual steering angle θHd changed within a range of ± 180 [deg].
The virtual steering angle θHd is input to the above formula (1) as the input angle tan θ _In of the universal joint 7. Thereby, the output angle θ _out of the universal joint 7 is calculated.

Next, the output angle θ _out of the universal joint 7 calculated as described above is input to the above equation (1) as the input angle tan θ _In of the universal joint 11, and the output angle θ _out of the universal joint 11 is calculated. Then, the output angle θ _out of the universal joint 11 is calculated as the steering side clutch angle θcl_in.
Then, the clutch angle deviation correction value dθCLD calculated by the clutch angle deviation correction value calculation unit 92 is added to the steering side clutch angle θcl_in. Thus, the turning angle correction value calculation turning side clutch angle Pθcl_outD is calculated (“Pθcl_outD = θcl_in + dθCLD” shown in FIG. 15).

Then, the turning angle correction value calculation turning side clutch angle Pθcl_outD calculated as described above is input as the input angle tan θ _In of the universal joint 19 to the model equation E3, and the output angle θ _out of the universal joint 19 is set. calculate. Further, the calculated output angle θ _out of the universal joint 19 is input to the model equation E4 as the input angle tan θ _In of the universal joint 23, and the output angle θ _out of the universal joint 23 is calculated.

Next, the calculated output angle θ _out of the universal joint 23 is input as the input angle tan θ _In of the virtual universal joint UJD to the following model equation E5 to calculate the output angle θ _out of the universal joint UJD.
E5. The correction joint angle α _D calculated by the correction joint angle calculation unit 86 is input as “α” to the above equation (1), and the correction phase calculated by the correction phase angle calculation unit 88 as “θ _offset ”. Model equation in which the angle θ _offsetD (0 [deg] or −90 [deg]) is input. That is, in the present embodiment, the steered wheels 24 of the steered wheels 24 are based on the virtual steering angle θHd changed within a range of ± 180 [deg]. In the process of calculating the turning angle, the virtual universal joint UJD is arranged closer to the steered wheel 24 than the universal joint 23.

_Further , the model equation using the correction joint angle α _D as “α” and the correction phase angle θ _offsetD as “θ _offset ” shown in the above equation (1) shown in FIG. Corresponds to the joint output angle calculation model.
Here, the virtual universal joint output angle calculation model is a different model formula from the actual universal joint output angle calculation model. The virtual universal joint output angle calculation model includes an angle obtained by adding a phase angle to a steered wheel side input angle, a steered wheel side output angle, an input side axis and an output side axis of the virtual universal joint UJD in plan view. It is a model formula which shows the relationship of the joint angle (alpha) which is an angle made.

The steering wheel side input angle is an angle input from the steering wheel 32 side to the virtual universal joint UJD. The steered wheel side output angle is an angle obtained by outputting the steered wheel side input angle to the steered wheel 24 side via the virtual universal joint UJD.
After calculating the output angle theta _out of the universal joint UJD, the output angle theta _out of the calculated universal joint UJD, subtracting the offset component of each universal joint (7,11,19,23, UJD). Thereby, the influence by the offset component of each universal joint (7, 11, 19, 23, UJD) is removed from the output angle θ _out of the universal joint UJD, and the turning angle is calculated.

Here, the offset component of each universal joint (7, 11, 19, 23, UJD) is calculated, for example, by inputting the correction phase angle θ _offsetD into the universal joint offset component calculation model.
In addition to this, in the process of calculating the turning angle, the output angle θ _out of the universal joint UJD obtained by dividing the offset component of each universal joint (7, 11, 19, 23, UJD) is used using the torque sensor model described above. To correct.

The turning angle is continuously calculated by continuously performing the above-described processing while changing the virtual steering angle θHd within a range of ± 180 [deg]. Furthermore, by subtracting the virtual steering angle θHd corresponding from turning angle was continuously calculating (virtual steering angle θHd entered in the above equation as the input angle tan .theta _{an In} universal joints 7 (1)), the reference correction necessity Calculate the input / output angular deviation for judgment.

The correction command value output unit 96 corrects the phase angle θ _offset3 to the steered side clutch angle calculation unit 68 according to the increase / decrease threshold value according to the determination content and determination result by the phase angle correction necessity determination unit 94. Output the value. In addition to this, the correction command value output unit 96 corrects the phase angle θ _offset1 to the turning angle calculation unit 76 according to the increase / decrease threshold value according to the determination content and determination result by the phase angle correction necessity determination unit 94. Outputs the correction command value.

Specifically, when it is determined that the maximum value of the maximum change width of the actual input / output angle deviation exceeds the maximum value maxL3 and the correction of the phase angle is necessary, the turning-side clutch angle calculation unit 68, A correction command value for increasing the phase angle θ _offset3 according to the increase / decrease threshold is output. In addition, a correction command value for increasing the phase angle θ _offset1 according to the increase / decrease threshold value is output to the turning angle calculation unit 76.

On the other hand, when it is determined that the maximum value of the maximum change width of the actual input / output angle deviation is less than the maximum value maxL2 and the correction of the phase angle using the correction phase angle is necessary, the steering side clutch angle calculation unit To 68, a correction command value for decreasing and correcting the phase angle θ _{offset3 according} to the increase / decrease threshold is output. In addition, a correction command value for correcting the decrease of the phase angle θ _offset1 according to the increase / decrease threshold is output to the turning angle calculation unit 76.
Here, in the present embodiment, the increase / decrease threshold is 5 [deg] in terms of the virtual steering angle θHd.
For this reason, when it is determined that the maximum value of the actual input / output angle deviation maximum change width exceeds the maximum value maxL3 and the correction of the phase angle is necessary, the phase angle is transferred to the steering side clutch angle calculation unit 68. A correction command value that increases 5 [deg] by converting θ _offset3 into a virtual steering angle θHd is output. In addition, a correction command value for converting the phase angle θ _offset1 to the virtual steering angle θHd and increasing it by 5 [deg] is output to the turning angle calculator 76.

On the other hand, when it is determined that the maximum value of the maximum change width of the actual input / output angle deviation is less than the maximum value maxL2 and the correction of the phase angle is necessary, the phase angle θ _{offset3 is sent} to the steering side clutch angle calculation unit 68. Is converted into a virtual steering angle θHd, and a correction command value that decreases 5 [deg] is output. In addition, a correction command value for converting the phase angle θ _offset1 to the virtual steering angle θHd and reducing it by 5 [deg] is output to the turning angle calculation unit 76.
As described above, the correction angle calculation block 78 determines the phase angle of the actual universal joint output angle calculation model according to the increase / decrease threshold based on the steering angle, the actual universal joint output angle calculation model, and the virtual universal joint output angle calculation model. to correct. This correction is performed so that the neutral position of the steering wheel 32 and the neutral position of the steered wheel 24 are approximated.

  The correction angle calculation block 78 performs processing for correcting the phase angle of the universal joint output angle calculation model according to the increase / decrease threshold based on the actual machine turning angle and the virtual turning angle and the increase / decrease threshold. The actual turning angle is a turning angle calculated by inputting a steering angle to an actual universal joint output angle calculation model. The virtual turning angle is the same value as the actual turning angle for the virtual universal joint output angle calculation model and the actual universal joint output angle calculation model for the virtual universal joint.

Specifically, the correction angle calculation block 78 calculates the actual machine turning angle maximum value and the virtual turning angle maximum value, and when the actual machine turning angle maximum value is outside the range of the absolute value of the increase / decrease threshold. The phase angle of the universal joint output angle calculation model is corrected according to the increase / decrease threshold value.
The actual turning angle maximum value is the maximum turning angle when the current steering angle θH input to the universal joint output angle calculation model for the universal joint connecting the torque transmission path is changed within a preset range. Value. Here, the universal joint that connects the torque transmission paths is a universal joint (7, 11, 19, 23) mounted on the vehicle.

The maximum value of the virtual steering angle is the steering angle when the virtual steering angle θHd input to the universal joint output angle calculation model for the virtual universal joint and the universal joint mounted on the vehicle is changed within a preset range. Is the maximum value.
Here, the virtual universal joint is a universal joint (UJD) that virtually connects the torque transmission paths in calculation.

The correction angle calculation block 78 calculates the actual input / output angle deviation maximum change width PPr and the virtual input / output angle deviation maximum change width PPd. Further, based on the absolute value (| PPr−PPd |) of the difference between the actual machine input / output angle deviation maximum change width PPr and the virtual input / output angle deviation maximum change width PPd, the universal joint output angle calculation model for the virtual universal joint UJD It performs a process of correcting the joint angle alpha _D.
Further, the correction angle calculation block 78 sets the position of the virtual universal joint UJD closer to the steered wheel 24 than the other universal joints (7, 11, 19, 23) mounted on the vehicle, so that the maximum virtual steered angle is reached. Processing to calculate a value is performed.

In addition, the correction angle calculation block 78 calculates a change angle in which the virtual steering angle θHd input to the universal joint output angle calculation model for the virtual universal joint and the universal joint mounted on the vehicle is changed via each universal joint. Furthermore, the offset component of each universal joint (7, 11, 19, 23, UJD) calculated using the universal joint offset component calculation model is subtracted from the calculated change angle. Thereby, the process which calculates a virtual turning angle maximum value is performed.
Further, the correction angle calculation block 78 corrects the phase angle of the universal joint reverse output angle calculation model according to the increase / decrease threshold when the actual turning angle maximum value is outside the range of the absolute value of the increase / decrease threshold. Do.

(Principle for establishing universal joint output angle calculation model)
Hereinafter, the principle that the universal joint output angle calculation model is established will be described with reference to FIGS. 1 to 15 and FIGS.
FIG. 16 is a diagram illustrating the relationship between the rotation axis of a single universal joint and the rotational motion around the rotation axis. In FIG. 16, the steering wheel 32 is schematically shown for explanation. That is, the single universal joint shown in FIG.
As shown in FIG. 16, the universal joint has three rotation axes (x-axis, y-axis, and z-axis). ) To (7). Expression (5) is an expression indicating a rotation matrix R (x, θ) around the x axis, and Expression (6) is an expression indicating a rotation matrix R (y, θ) around the y axis. Expression (7) is an expression indicating a rotation matrix R (z, θ) around the z axis.

  The rotation matrices R (x, θ), R (y, θ), and R (z, θ) around the rotation axes shown in the above equations (5) to (7) are expressed by the following equations (8). As shown in FIG. 2, it is possible to convert the rotation matrix R into one.

Further, as shown in FIG. 17, the rotation of the input side shaft replaced by the symbol "φ" from theta ₀ shown in FIG. 16, symbols inclination angle of the output side of the shaft relative to the z-axis "theta _z The rotation angle of the shaft on the output side (which may be described as “output angle” in the following description) is defined by the symbol “Ψ”. Thereby, the definition of the attitude angle in a universal joint is shown by the following formulas (9) to (11). FIG. 17 is a diagram illustrating the relationship between the input side shaft and the output side shaft in the universal joint. In FIG. 17, for the sake of explanation, the flow of force from the input side shaft to the output side shaft is indicated by straight arrows.

Here, when the constraint conditions shown by the following equations (12) and (13) are added to the above equations (9) to (11), the relationship between the input angle tanθ ₀ to the universal joint and the output angle ψ is It is shown by the following formula (14).

In the above equation (14), when the output angle Ψ is replaced with the universal joint output angle θ _out and the input angle tan θ ₀ is replaced with the universal joint input angle tan θ _In , the following equation (15) is established.

Here, the above equation (15) is an equation indicating the relationship between the universal joint input angle tan θ _In and the output angle θ _out in a state where the universal joint phase angle θ _offset does not exist.
In addition, as the configuration of the vehicle, it is rare that the input shaft and the output shaft of each universal joint are arranged in series according to the layout of various components between the steering wheel 32 and the steered wheels 24. For this reason, a configuration in which the phase angle θ _offset of the universal joint exists is common.

That is, as shown in FIG. 18, in a vehicle having a general configuration, a phase angle θ _offset exists between the input angle tan θ _In and the output angle θ _out of the universal joint. FIG. 18 is a diagram illustrating the relationship between the input side axis and the output side axis in the universal joint and the phase angle. In FIG. 18, for the sake of explanation, the flow of force from the input side shaft to the output side shaft is indicated by straight arrows.
Therefore, when the phase angle θ _offset is added to the input angle tan θ _In with respect to the relationship between the input angle tan θ _In and the output angle θ _out of the universal joint shown in the above formula (15), the above formula (1) The universal joint output angle calculation model shown is established.

(Principle for establishing universal joint offset component calculation model)
Hereinafter, the principle that the universal joint offset component calculation model is established will be described with reference to FIGS.
When calculating the turning angle of the steered wheels 24, as described above, the output angle theta _out of the universal joint 23, to eliminate the influence of offset component of each universal joint. Therefore, in the above equation (15), when the input angle tan θ _In and the output angle θ _out of the universal joint are 0 [°], the offset component of each universal joint is subtracted by subtracting the offset component from the following equation (16). Remove the effects of ingredients.

Therefore, when the offset component of the universal joint is subtracted from the relationship between the input angle tan θ _In and the output angle θ _out of the universal joint represented by the above equation (15), the universal joint offset component represented by the above equation (3) is obtained. A calculation model is established.

(Steering side previous processing content storage unit MA, reaction force side previous processing content storage unit MB)
Hereinafter, with reference to FIG. 1 to FIG. 18, the configuration of the steered side previous processing content storage unit MA and the configuration of the reaction force side previous processing content storage unit MB will be described.
The steered side previous processing content storage unit MA is formed using, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory).
Further, the steered side previous processing content storage unit MA receives an input of an information signal including the state of the engine from the engine controller 52, and further receives an information signal including the current steering angle of the steering wheel 32 from the steering angle sensor 34. Receive input. In addition to this, the steered-side previous processing content storage unit MA receives an input of an information signal including the clutch angle deviation from the clutch angle deviation calculation unit 70, and further turns the steered wheels 24 from the turning angle calculation unit 76. Receives information signal including steering angle.

Then, the steered side previous processing content storage unit MA stores the current steering angle, the clutch angle deviation, and the steered angle of the steered wheels 24 at the time when the ignition switch is turned off.
The reaction force side previous process content storage unit MB is formed by using, for example, an EEPROM, like the steered side previous process content storage unit MA.
The reaction force side previous processing content storage unit MB is similar to the steering side previous processing content storage unit MA from the engine controller 52, the steering angle sensor 34, the clutch angle deviation calculation unit 70, and the turning angle calculation unit 76, respectively. , Receive information signal input.
Then, the reaction force side previous process content storage unit MB, like the steered side previous process content storage unit MA, the current steering angle, the clutch angle deviation, and the steered wheels 24 at the time when the ignition switch is turned off. The turning angle is memorized.

(Processing performed by the command calculation unit 54)
Next, processing performed by the command calculation unit 54 will be described with reference to FIGS. 1 to 18 and FIGS. 19 to 21. FIG.
The processing performed by the command calculation unit 54 includes, for example, processing performed before shipment of the vehicle and processing performed on the vehicle after shipment.

Processing Performed Before Shipment of Vehicle FIG. 19 is a flowchart showing processing performed before shipment of the vehicle.
As processing calculation unit 54 is performed before shipment of the vehicle, a process of calculating and storing the joint angle alpha, a process of storing the phase angle theta _offset, there is a process of correcting the phase angle theta _offset stored.
As shown in FIG. 19, when the process to be performed before the vehicle is shipped (START), the process of step S10 is first performed.
In step S10, for example, in a maintenance shop or the like, both the steering angle of the steering wheel 32 and the actual turning angle of the steered wheels 24 are adjusted to the neutral position (the “steering angle and actual turning angle shown in the figure are set to the neutral position”). adjust. When the steering angle and the actual turning angle are adjusted to the neutral position in step S10, the process performed by the command calculation unit 54 before the vehicle is shipped moves to step S20.

In step S20, the joint angles α _{1 to} α ₄ are calculated and stored in the steering side clutch angle calculating unit 66, the steered side clutch angle calculating unit 68, and the steered angle calculating unit 76 (see “Joint angle α shown in the figure”). Calculate / store ”). When the joint angle α is calculated and stored in step S20, the process performed by the command calculation unit 54 before the vehicle is shipped moves to step S30.
In step S30, the phase angles θ _{offset1 to} θ _offset4 are _stored in the steering side clutch angle calculation unit 66, the turning side clutch angle calculation unit 68, and the turning angle calculation unit 76 (“phase angle θ _offset shown in the figure is stored”). )). When the phase angle θ _offset is stored in step S30, the process performed by the command calculation unit 54 before the vehicle is shipped moves to step S40.

In step S40, the deviation of the steering motor rotation angle with respect to the steering angle is stored in the neutral position storage unit 60 as the relationship between the steering angle and the steering motor rotation angle ("neutral position storage" shown in the figure). If the relationship between the steering angle and the turning motor rotation angle is stored in step S40, the process performed by the command calculation unit 54 before the vehicle is shipped moves to step S50.
In step S50, the state in which the steering angle and the actual turning angle are adjusted to the neutral position in step S10 is maintained, and the actual machine input / output angle deviation calculation unit 84 calculates the actual machine input / output angle deviation maximum change width (shown in the figure). "Calculate the maximum change width of the actual input / output angle deviation"). When the actual input / output angle deviation maximum change width is calculated in step S50, the process performed by the command calculation unit 54 before the vehicle is shipped moves to step S60.

In step S60, calculates the correction joint angle alpha _D by the correction joint angle computing unit 86, "the correction joint angle alpha _D showing a correction phase angle theta _OffsetD in operation (figure by correcting the phase angle calculating section 88 "Calculate the correction phase angle θ _offsetD "). In step S60, when calculating a correction phase angle theta _OffsetD the correction joint angle alpha _D, processing the command calculation unit 54 performed before shipment of the vehicle, the process proceeds to step S70.
In step S70, the steering side clutch angle correction value calculation unit 90 calculates the steering side clutch angle correction value, and the clutch angle deviation correction value calculation unit 92 calculates the clutch angle deviation correction value ("steering" shown in the figure). Calculate side clutch angle correction value Calculate clutch angle deviation correction value ”). When the steered side clutch angle correction value and the clutch angle deviation correction value are calculated in step S70, the process performed by the command calculation unit 54 before the vehicle is shipped proceeds to step S80.

In step S80, the phase angle correction necessity determination unit 94 determines whether or not it is necessary to correct the phase angle using the correction phase angle calculated by the correction phase angle calculation unit 88 ("phase angle shown in the drawing" Is correction necessary? ”).
If it is determined in step S80 that the correction of the phase angle using the correction phase angle is necessary ("Yes" shown in the figure), the process performed by the command calculation unit 54 before the vehicle is shipped goes to step S82. Transition.

On the other hand, if it is determined in step S80 that the correction of the phase angle using the correction phase angle is not necessary ("No" shown in the figure), the process performed by the command calculation unit 54 before the vehicle is shipped is step S80. The process proceeds to S84.
In step S 82, the correction command value output unit 96 outputs the correction command value to the turning side clutch angle calculation unit 68 and the turning angle calculation unit 76. Thus, the phase angle theta _OFFSET3 used in the process of calculating the steered side clutch angle, corrects the phase angle theta _offset1 used in the process of calculating the steering angle of steered wheels 24 (shown in FIG. "Correct the phase angle" ) In step S82, the a phase angle theta _OFFSET3 used in the process of calculating the steered side clutch angle and corrects the phase angle theta _offset1 used in the process of calculating the steering angle of the steered wheels 24, calculation unit before shipping of the vehicle The processing performed by 54 ends (END).

In step S84, the correction command value is not output from the correction command value output unit 96, and the phase angle θ _offset3 used in the process of calculating the turning-side clutch angle and the phase used in the process of calculating the turning angle of the steered wheels 24 The angle θ _offset1 is maintained without correction (“maintain phase angle” shown in the figure). In step S84, the a phase angle theta _OFFSET3 used in the process of calculating the steered side clutch angle, maintaining the phase angle theta _offset1 used in the process of calculating the steering angle of the steered wheels 24, calculation unit before shipping of the vehicle The processing performed by 54 ends (END).

Processing performed on the vehicle after shipment The processing performed by the command calculation unit 54 on the vehicle after shipment includes processing for calculating and storing the clutch angle deviation and processing for calculating the turning angle of the steered wheels 24. There is a process of correcting the relationship between the steering angle and the turning motor rotation angle.
FIG. 20 is a flowchart showing a process of calculating and storing the clutch angle deviation among the processes performed on the vehicle after shipment. Note that the command calculation unit 54 performs processing described below at a preset period (for example, 5 [ms]).
As shown in FIG. 20, when the process of calculating the clutch angle deviation is started (START), first, the process of step S100 is performed.
In step S100, a process ("IGN-OFF?" Shown in the drawing) for determining whether or not the ignition switch is in an OFF state is performed.
If it is determined in step S100 that the ignition switch is in the OFF state (“Yes” shown in the drawing), the process of calculating the clutch angle deviation moves to step S110.

On the other hand, when it is determined in step S100 that the ignition switch is not in the OFF state (“No” shown in the figure), the process of calculating the clutch angle deviation repeats the process of step S100.
In step S110, the clutch state switching unit 64 outputs a clutch current command for switching the clutch 6 to the engaged state to the clutch 6. In addition to this, referring to the clutch drive current output to the clutch 6, it is determined whether or not the clutch 6 is in the engaged state (completely engaged state not including the slip engaged state) ("clutch engagement shown in the figure"?")I do.
If it is determined in step S110 that the clutch 6 is in the engaged state (“Yes” shown in the drawing), the process of calculating the clutch angle deviation proceeds to step S120.

On the other hand, if it is determined in step S110 that the clutch 6 is not engaged ("No" shown in the figure), the process of calculating the clutch angle deviation repeats the process of step S110.
In step S120, it is determined whether or not the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold ("Vts is within the range of the steering-side clutch angle calculation torque threshold" shown in the figure). )I do.
If it is determined in step S120 that the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold ("Yes" shown in the figure), the process of calculating the clutch angle deviation proceeds to step S130. .

On the other hand, if it is determined in step S120 that the torque sensor value Vts is outside the range of the steering clutch angle calculation torque threshold ("No" shown in the figure), the process of calculating the clutch angle deviation is performed in step S120. Repeat the process.
In step S130, the steering clutch angle calculator 66 calculates the steering clutch angle θcl_in (“calculates the steering clutch angle θcl_in” shown in the drawing) using the universal joint output angle calculation model. When the steering side clutch angle θcl_in is calculated in step S130, the process of calculating the clutch angle deviation proceeds to step S140.

In step S140, a process for determining whether or not the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold ("Vts is within the range of the steering-side clutch angle calculation torque threshold shown in the figure"). ?")I do.
If it is determined in step S140 that the torque sensor value Vts is within the range of the steering-side clutch angle calculation torque threshold ("Yes" shown in the figure), the process of calculating the clutch angle deviation proceeds to step S150. To do.

On the other hand, if it is determined in step S140 that the torque sensor value Vts is outside the range of the steering clutch angle calculation torque threshold ("No" in the figure), the process of calculating the clutch angle deviation is performed in step S140. Repeat the process.
In step S150, the steering-side clutch angle calculation unit 68 calculates the steering-side clutch angle θcl_out using the universal joint reverse output angle calculation model (“calculates the steering-side clutch angle θcl_out” shown in the figure). Process. When the steered side clutch angle θcl_out is calculated in step S150, the process of calculating the clutch angle deviation proceeds to step S160.

In step S160, the steering side clutch angle θcl_in calculated in step S130 is subtracted from the steered side clutch angle θcl_out calculated in step S150. Thereby, in step S160, the clutch angle deviation calculating unit 70 performs a process of calculating the clutch angle deviation dθCL (“calculate the clutch angle deviation dθCL” shown in the drawing). When the clutch angle deviation dθCL is calculated in step S160, the process for calculating the clutch angle deviation proceeds to step S170.
In step S170, the clutch angle deviation storage unit 72 stores the clutch angle deviation dθCL calculated in step S160 (“stores clutch angle deviation dθCL” shown in the figure). When the clutch angle deviation dθCL is stored in step S170, the process of calculating the clutch angle deviation is ended (END).

Processing for calculating the turning angle of the steered wheels 24 and processing for correcting the relationship between the steering angle and the turning motor rotation angle FIG. It is a flowchart which shows the process which calculates the process which calculates a steering angle, and the relationship between a steering angle and a steering motor rotation angle.
The flowchart shown in FIG. 21 starts (START) when the ignition switch changes from the off state to the on state, and first, the process of step S200 is performed.
In step S200, a process of determining whether or not the torque sensor value Vts is within the range of the turning angle calculation torque threshold (“Vts is within the range of the turning angle calculation torque threshold?” Shown in the figure). Do.
If it is determined in step S200 that the torque sensor value Vts is within the range of the turning angle calculation torque threshold ("Yes" shown in the figure), the process of calculating the turning angle of the steered wheels 24 is step S210. Migrate to

On the other hand, when it is determined in step S200 that the torque sensor value Vts is outside the range of the turning angle calculation torque threshold ("No" shown in the figure), the process of calculating the turning angle of the steered wheels 24 is as follows. The process of step S200 is repeated.
In step S210, the current steering angle when the ignition switch is turned on is input to the universal joint output angle calculation model, and the output angle θ _out of the universal joint 11 is calculated as the steering clutch angle θcl_in. Thereby, in step S210, the process of calculating the output angle of the steering-side universal joint (“calculating the output angle of the steering-side universal joint” shown in the figure) is performed. When the output angle of the steering-side universal joint is calculated in step S210, the process of calculating the turning angle of the steered wheels 24 proceeds to step S220.

  In step S220, the clutch angle deviation dθCL stored in step S170 is added to the steering clutch angle θcl_in, which is the output angle of the steering universal joint calculated in step S210. As a result, in step S220, a steering angle calculation-use turning side clutch angle Pθcl_out is calculated (“calculate the turning angle calculation-use turning-side clutch angle Pθcl_out” shown in the drawing). In step S220, when the turning angle calculation-use turning side clutch angle Pθcl_out is calculated, the processing for calculating the turning angle of the steered wheels 24 proceeds to step S230.

In step S230, the turning angle calculation turning-side clutch angle Pθcl_out calculated in step S220 is input to the universal joint output angle calculation model, and the output angle θ _out of the universal joint 23 is calculated. Thereby, in step S230, the process which calculates the output angle of a steering side universal joint ("calculate the output angle of a steering side universal joint" shown in a figure) is performed. When the output angle of the steered universal joint is calculated in step S230, the process of calculating the steered angle of the steered wheels 24 proceeds to step S240.

In step S240, the output angle theta _out of the universal joint 23 calculated in step S230, the performs processing of subtracting an offset component based on the universal joint offset component calculation model (shown in FIG. "Subtracting the offset component"). Thereby, in step S240, the influence by the offset component of each universal joint (7, 11, 19, 23) is removed from the output angle θ _out of the universal joint 23. When the offset component is subtracted from the output angle θ _out of the universal joint 23 in step S240, the process of calculating the turning angle of the steered wheels 24 proceeds to step S250.

In step S250, a process of correcting the output angle θ _out of the universal joint 23 obtained by subtracting the offset component in step S240 using a torque sensor model (“corrected by the torque sensor model” shown in the figure) is performed. When the output angle θ _out of the universal joint 23 is corrected by the torque sensor model in step S250, the process of calculating the turning angle of the steered wheels 24 proceeds to step S260. Then, the process shifts from the process of calculating the steered angle of the steered wheels 24 to the process of correcting the relationship between the steering angle and the steered motor rotation angle.

In step S260, the relationship between the current steering angle used in step S210 and the output angle θ _out corrected in step S250, and the steering angle and the turning motor rotation angle stored in the neutral position storage unit 60 in step S40 described above. Browse relationships. Then, current and deviation a is shipped after the deviation between the output angle theta _out corrected by the steering angle and the step S250 that used in step S210, whether the pre-shipment deviation which is a deviation stored in the neutral position storage unit 60 are different Processing for determination (“deviation after shipment ≠ deviation before shipment?” Shown in the figure) is performed.
If it is determined in step S260 that the post-shipment deviation and the pre-shipment deviation are different (“Yes” shown in the figure), the process of correcting the relationship between the steering angle and the turning motor rotation angle proceeds to step S270.

On the other hand, if it is determined in step S260 that the post-shipment deviation and the pre-shipment deviation are equal (“No” shown in the figure), the process of correcting the relationship between the steering angle and the turning motor rotation angle proceeds to step S280. To do.
In step S270, the relationship between the steering angle and the turning motor rotation angle stored in the neutral position storage unit 60 in step S40 is corrected to the relationship based on the post-shipment deviation corrected in step S250 ("Neutral position shown in the figure"). Correction ”) is performed. In step S270, when the relationship between the steering angle stored in the neutral position storage unit 60 and the turning motor rotation angle is corrected, the processing for correcting the relationship between the steering angle and the turning motor rotation angle proceeds to step S290.

In step S280, a process of maintaining the relationship between the steering angle and the turning motor rotation angle stored in the neutral position storage unit 60 in step S40 without correcting ("maintain neutral position" shown in the figure) is performed. In step S280, if the relationship between the steering angle stored in the neutral position storage unit 60 and the turning motor rotation angle is maintained, the process of correcting the relationship between the steering angle and the turning motor rotation angle proceeds to step S290.
In step S290, the clutch state switching unit 64 outputs a clutch current command for switching the clutch 6 to the released state to the clutch 6 ("output clutch release command" shown in the figure). In step S290, when a clutch current command for switching the clutch 6 to the disengaged state is output to the clutch 6, the process of correcting the relationship between the steering angle and the turning motor rotation angle ends (END).

(Operation)
Next, an example of an operation performed using the vehicle steering control device 1 of the present embodiment will be described with reference to FIGS. 1 to 21 and FIG. FIG. 22 is a time chart showing the operation of the vehicle using the vehicle steering control device 1 of the present embodiment.
The time chart shown in FIG. 22 shows a state where the ignition switch is on, such as when the vehicle is running, and the torque transmission path is mechanically separated to control the SBW system (“SBW” shown in the figure). Starts during system control ”). The control of the SBW system is, for example, control of the turning angle in accordance with the vehicle speed, such as control (variable gear control) for reducing the degree of change of the turning angle with respect to the steering angle when traveling at high speed than when traveling at low speed. . In addition, the control of the SBW system includes the relationship between the steering angle stored in the neutral position storage unit 60 and the turning motor rotation angle, the current steering angle θH detected by the steering angle sensor 34, and the vehicle speed detected by the vehicle speed sensor 50. To do.

Then, at the time t1 when the ignition switch is switched from the on state to the off state (“IGN OFF” in the figure), such as when the vehicle is parked, the control of the SBW system is terminated. Further, processing at the end of SBW system control ("processing at the end of SBW system" shown in the figure) is performed.
The process performed at time t1 is a process of switching the clutch 6 to the engaged state (“clutch engagement” shown in the drawing) to mechanically connect the torque transmission path, and further calculating and storing the clutch angle deviation dθCL.

Here, the phase angle theta _offset1 used in the process of calculating the steering angle, if the phase angle theta _OFFSET3 used in the process of calculating the steered side clutch angle is corrected in accordance with the increase or decrease threshold, at the time point t1, The clutch angle deviation dθCL is calculated using the corrected phase angle. As a result, even if an error occurs in the joint angle α of each universal joint (7, 11, 19, 23), this error can be reduced. This can be _performed by calculation using a universal joint output angle calculation model in which the phase angle θ _offset1 is corrected and a universal joint reverse output angle calculation model in which the phase angle θ _offset3 is corrected.

When the torque transmission path is mechanically connected, the operation of the steering wheel 32 is mechanically transmitted to the steered wheels 24 (“Manual Steer” shown in the figure). The situation where the clutch 6 is switched to the connected state includes, for example, a situation where the steered motor 2 is overheated, in addition to the situation where the ignition switch is switched from the on state to the off state.
For example, when starting a parked vehicle from a state where the torque transmission paths are mechanically connected, the ignition switch is switched to the on state.
At this time, at the time t2 when the ignition switch is switched to the on state (“IGN OFF” in the drawing), the processing at the time of starting the SBW system control (“processing at the time of starting the SBW system” shown in the drawing) is performed.

The processing performed at time t2 is processing performed before switching the clutch 6 to the disengaged state (“clutch disengagement” shown in the figure), processing for calculating the steered angle of the steered wheels 24, steering angle and steered motor. This process corrects or maintains the relationship with the rotation angle.
Here, when the phase angle θ _offset1 used in the process of calculating the turning angle is corrected according to the increase / decrease threshold value, the turning of the steered wheels 24 is performed using the corrected phase angle θ _offset1 at time t2. Calculate the corner. Thereby, even if an error occurs in the joint angle α of each universal joint (7, 11, 19, 23), the universal joint output angle calculation model in which the error is corrected for the phase angle θ _offset1 is obtained. It can be reduced by the calculation used.

When the process of calculating the steered angle of the steered wheels 24 and the process of correcting or maintaining the relationship between the steering angle and the steered motor rotation angle are finished, the clutch 6 in the connected state is switched to the released state, and the SBW system Control is started ("SBW system in control" shown in the figure).
At time t2, the ignition switch is turned on, and the process of calculating the turning angle of the steered wheels 24 and the process of correcting or maintaining the relationship between the steering angle and the turning motor rotation angle are started. However, the present invention is not limited to this. That is, for example, by the operation of unlocking the door (front door) of the vehicle, the command calculation unit 54 and the like are activated to calculate the turning angle of the steered wheels 24, the steering angle, and the turning motor rotation angle. The process of correcting or maintaining the relationship may be started.

As described above, in the vehicle steering control device 1 according to the present embodiment, even when the steering angle of the steering wheel 32 is changed while the ignition switch is in the OFF state, as described below, the vehicle speed It is possible to appropriately carry out the control of the turning angle in accordance with.
That is, when the turning angle is controlled in accordance with the vehicle speed, the degree of change in the turning angle with respect to the steering angle differs depending on the vehicle speed (steering angle: turning angle = 1: X 1 <X at low speed, X <1) at high speed. On the other hand, when the steering angle of the steering wheel 32 is changed while the ignition switch is in the off state, the clutch 6 is in the connected state, so the change degree of the steering angle and the change degree of the turning angle are equal. (Steering angle: turning angle = 1: 1).

  Therefore, for example, when the vehicle is traveling at a low speed such as when the vehicle is parked, the degree of change in the turning angle with respect to the steering angle is increased, and the amount of change in the turning angle is increased even if the amount of change in the turning angle is small. In this case, if the steering angle of the steering wheel 32 changes while the ignition switch is off and the clutch 6 is in the engaged state, the relationship between the steering angle and the steering angle when the ignition switch is off. Changes. This occurs when the turning angle is turned from the neutral position. Then, when the turning angle is controlled according to the vehicle speed with reference to the state in which the relationship between the turning angle and the steering angle is changed, the SBW system is controlled while the relationship between the turning angle and the steering angle is changed. As a result, the control of the SBW system becomes inappropriate.

On the other hand, in the vehicle steering control device 1 according to the present embodiment, when the ignition switch is switched to the on state, before the clutch 6 is switched to the released state, the steering angle of the steering wheel 32 and the clutch angle deviation dθCL are determined. Then, the turning angle of the steered wheel 24 is calculated. For this reason, the relationship between the steering angle and the turning motor rotation angle in a state where both the steering angle and the actual turning angle are adjusted to the neutral position, the steering angle of the steering wheel 32, the clutch angle deviation dθCL, and the respective models. Based on this, it becomes possible to calculate and store appropriately.
Thereby, even when the steering angle of the steering wheel 32 is changing while the ignition switch is in the OFF state, the above-described control of the turning angle according to the vehicle speed can be appropriately performed. It becomes.

For this reason, for example, even when the parked vehicle is started while turning (turning start), that is, when the parked vehicle is started while steering the steering wheel 32, the steering angle and the rotation are changed. It becomes possible to correct the relationship with the rudder motor rotation angle. Accordingly, even when the parked vehicle is started while steering the steering wheel 32, the SBW system can be appropriately controlled.
In this case, for example, even when the configuration of the vehicle is a configuration in which the change in the steering angle that is changed while the ignition switch is in the OFF state is corrected by straight traveling, It becomes possible to appropriately control the SBW system.

In the vehicle steering control device 1 of the present embodiment, it is possible to calculate the turning angle used in the process of determining whether or not to correct the phase angle of the universal joint output angle calculation model. This calculation is performed based on the joint angle α and the phase angle θ _offset of the universal joints (7, 11, 19, 23) actually provided in the vehicle and the virtual universal joint UJD.
For this reason, even if there is an error in the joint angle α of the universal joint that the vehicle actually has, this error should be reduced by calculation using the universal joint output angle calculation model with the phase angle corrected. Is possible.
The steering angle sensor 34 described above corresponds to a steering angle detection unit.

Moreover, the steering motor angle sensor 16 mentioned above respond | corresponds to a steering actuator rotation angle detection part.
The pinion shaft torque sensor 46t described above corresponds to a steering torque detector.
Moreover, the universal joint 7, the universal joint 11, the universal joint 19, and the universal joint 23 described above correspond to an actual universal joint.
The correction processing block 78 described above corresponds to an actual universal joint output angle calculation model correction unit, a virtual universal joint output angle calculation model correction unit, and a virtual universal joint reverse output angle calculation model correction unit.

The steering-side universal joint output angle calculation model and the steering-side universal joint output angle calculation model described above correspond to the actual universal joint output angle calculation model.
Further, as described above, the vehicle steering control method implemented by the operation of the vehicle steering control device 1 of the present embodiment is a method of correcting the phase angle of the actual universal joint output angle calculation model according to the increase / decrease threshold. is there.
Here, the phase angle of the actual universal joint output angle calculation model is corrected according to the increase / decrease threshold based on the steering angle, the actual universal joint output angle calculation model, and the virtual universal joint output angle calculation model. Further, the phase angle of the actual universal joint output angle calculation model is corrected so that the neutral position of the steering wheel 32 and the neutral position of the steered wheel 24 are approximated.

(Effects of the first embodiment)
In the present embodiment, the following effects can be obtained.
(1) The correction processing block 78 corrects the phase angle of the actual universal joint output angle calculation model according to the increase / decrease threshold based on the steering angle, the actual universal joint output angle calculation model, and the virtual universal joint output angle calculation model. To do. Here, the phase angle of the actual universal joint output angle calculation model is corrected so that the neutral position of the steering wheel 32 and the neutral position of the steered wheel 24 are approximated.
Therefore, the phase angle of the actual universal joint output angle calculation model can be corrected according to the steering state of the steering wheel 32 by the driver and the model formulas for the actual universal joint and the virtual universal joint mounted on the vehicle. .

As a result, it becomes possible to estimate the phase difference of the rotation angle generated between the shafts connected using the actual universal joint. As a result, even when the steering angle changes while the ignition switch is off, the steered angle can be calculated according to the phase difference of the rotation angle.
Therefore, it is possible to improve the estimation accuracy of the actual turning angle and appropriately control the SBW system.

In addition to this, even when an assembly error occurs in the members constituting the torque transmission path, it becomes possible to calculate the turning angle according to the assembly error, and improve the estimation accuracy of the actual turning angle. Thus, it becomes possible to appropriately control the SBW system.
The difference between the turning angle when the ignition switch is turned off and the actual turning angle when the ignition switch is turned on is the rotation that occurs between the shafts connected using the universal joint. This is because it occurs due to an angular phase difference. In addition, when an assembly error occurs in a member constituting the torque transmission path during the manufacture of the vehicle, such as when the steering wheel is installed, the above-mentioned inconstant speed changes, and the rotation angle generated between the shafts changes. This is because it is difficult to estimate the phase difference.

(2) The correction processing block 78 corrects the phase angle of the actual universal joint output angle calculation model according to the increase / decrease threshold value based on the actual machine turning angle and the virtual turning angle and the increase / decrease threshold value.
Therefore, the phase angle of the actual universal joint output angle calculation model can be corrected according to the actual turning angle based on the actual universal joint mounted on the vehicle and the virtual turning angle based on the virtual universal joint.
As a result, it is possible to estimate the phase difference of the rotation angle generated between the shafts connected using the actual universal joint, and to improve the estimation accuracy of the actual turning angle and appropriately control the SBW system. It becomes possible. In addition to this, even when an assembly error occurs in the members constituting the torque transmission path, it becomes possible to calculate the turning angle according to the assembly error, and improve the estimation accuracy of the actual turning angle. Thus, it becomes possible to appropriately control the SBW system.

(3) The correction processing block 78 calculates the actual machine turning angle maximum value and the virtual turning angle maximum value, and if the actual machine turning angle maximum value is outside the range of the absolute value of the increase / decrease threshold, the actual machine universal The phase angle of the joint output angle calculation model is corrected according to the increase / decrease threshold.
For this reason, it is possible to correct the phase angle of the actual universal joint output angle calculation model according to the maximum actual steering angle based on the actual universal joint implemented by the vehicle and the maximum virtual steering angle based on the virtual universal joint. It becomes possible.
As a result, it becomes possible to estimate the phase difference of the rotation angle that occurs between the shafts connected using the actual universal joint, and even if an assembly error occurs in the members that constitute the torque transmission path, the assembly error It is possible to calculate the turning angle according to the above. Thereby, the estimation accuracy of the actual turning angle can be improved and the SBW system can be appropriately controlled.

(4) The correction processing block 78 calculates the actual input / output angle deviation maximum change width PPr and the virtual input / output angle deviation maximum change width PPd. In addition, based on the absolute value | PPr−PPd | of the difference between the actual input / output angle deviation maximum change width PPr and the virtual input / output angle deviation maximum change width PPd, the joint angle α _{D of the} virtual universal joint output angle calculation model is calculated. Correct.
Therefore, the actual steering angle maximum value based on the actual universal joint, in accordance with the virtual steering angle maximum value based on the virtual universal joint obtained by correcting the joint angle alpha _D, corrects the phase angle of the actual universal joint output angle calculation model It becomes possible to do.
As a result, it becomes possible to estimate the phase difference of the rotation angle generated between the shafts connected by using the actual universal joint according to the deviation between the actual phase angle of the torque transmission path and the calculated phase angle. .

(5) The correction processing block 78 sets the position of the virtual universal joint UJD closer to the steered wheel 24 than the actual universal joint (7, 11, 19, 23) mounted on the vehicle, and the virtual steered angle maximum value. Is calculated.
For this reason, a process for correcting the phase angle of the actual universal joint output angle calculation model is performed between the universal joint 23 and the steered wheel 24 that are most affected by the assembly error generated in the members constituting the torque transmission path. It becomes possible.
As a result, it is possible to improve the estimation accuracy for estimating the phase difference of the rotation angle generated between the shafts connected using the actual universal joint.

(6) The correction processing block 78 calculates the change angle at which the virtual steering angle θHd input to the universal joint output angle calculation model for each universal joint (7, 11, 19, 23, UJD) has changed via each universal joint. To do. In addition to this, based on the value obtained by subtracting the offset component of each universal joint (7, 11, 19, 23, UJD) calculated using the universal joint offset component calculation model from the calculated change angle, the virtual turning angle Calculate the maximum value.
For this reason, it becomes possible to remove the influence by the offset component of each universal joint from the change angle which the virtual steering angle (theta) Hd changed via each universal joint (7, 11, 19, 23, UJD).
As a result, regardless of the phase angle of each universal joint, the virtual steering angle θHd can be calculated in accordance with the change in the steering angle transmitted by each universal joint through the torque transmission path. It becomes.

(7) The correction processing block 78 corrects the phase angle of the virtual universal joint reverse output angle calculation model according to the increase / decrease threshold when the actual turning angle maximum value is outside the range of the absolute value of the increase / decrease threshold. In addition to this, the turning side clutch angle calculation unit 68 inputs the turning motor rotation angle detected by the turning motor angle sensor 16 to the virtual universal joint reverse output angle calculation model in which the correction processing block 78 has corrected the phase angle. Then, the steered side clutch angle θcl_out is calculated.
For this reason, it becomes possible to correct the phase angle of the virtual universal joint reverse output angle calculation model in accordance with the actual turning angle maximum value based on the actual universal joint mounted on the vehicle.
As a result, the turning angle of the steered wheels 24 is calculated using the turning angle of the steered motor 24 detected by the steered motor angle sensor 16 and the virtual universal joint reverse output angle calculation model in which the phase angle is corrected according to the maximum actual turning angle. The steering angle can be calculated. Thereby, the calculation accuracy of the turning side clutch angle θcl_out can be improved, the calculation accuracy of the turning side calculation turning-side clutch angle Pθcl_out can be improved, and the calculation accuracy of the turning angle can be improved.

(8) The correction processing block 78 changes the current steering angle θH input to the actual universal joint output angle calculation model within a preset range with reference to the neutral position. Then, based on the change range based on the maximum value and the minimum value of the turning angle when the current steering angle θH is returned to the neutral position after being changed within a preset range, the actual input / output angle deviation maximum change width PPr. Is calculated.
Therefore, compared with the case where the actual machine input / output angle deviation maximum change width PPr is calculated by changing the current steering angle θH only in one direction, the calculated actual machine input / output angle deviation maximum change width PPr is affected by the hysteresis. A suppressed value can be obtained.
As a result, it is possible to improve the calculation accuracy of the actual machine input / output angle deviation maximum change width PPr, and it is possible to improve the estimation accuracy of the phase difference of the rotation angle generated between the shafts connected using the actual machine universal joint. It becomes.

(9) The correction processing block 78 changes the current steering angle θH input to the actual universal joint output angle calculation model to the upper limit value in a range set in advance with the neutral position as a reference, and then returns to the neutral position. Furthermore, after changing the current steering angle θH to the lower limit value of the preset range, and then returning the current steering angle θH to the neutral position, based on the change range based on the maximum value and the minimum value of the turning angle, The actual machine input / output angle deviation maximum change width PPr is calculated.
Therefore, the calculated actual machine input / output angle deviation maximum change width is compared with the case where the actual machine input / output angle deviation maximum change width PPr is calculated by changing the current steering angle θH to only one limit value within a preset range. It is possible to set PPr to a value that suppresses the influence of hysteresis.
As a result, it is possible to improve the calculation accuracy of the actual machine input / output angle deviation maximum change width PPr, and it is possible to improve the estimation accuracy of the phase difference of the rotation angle generated between the shafts connected using the actual machine universal joint. It becomes.

(10) The turning angle calculation unit 76 corrects the change angle at which the turning angle calculation turning-side clutch angle Pθcl_out has changed via the turning-side universal joint using the torsion angle of the torque transmission path. Based on this, the turning angle of the steered wheels 24 is calculated. Here, the torsion angle of the torque transmission path is calculated using a torque sensor model.
For this reason, even if the steering angle changes while the ignition switch is in the OFF state and a twist occurs in the torque transmission path, the twist generated in the torque transmission path is corrected using the torque sensor model. Is possible.
As a result, the turning angle of the steered wheels 24 is removed by removing the influence of the twist generated in the torque transmission path from the change angle at which the turning-side clutch angle Pθcl_out for turning angle calculation changes via the turning-side universal joint. Can be calculated.

(11) In the vehicle steering control method of the present embodiment, based on the steering angle, the actual universal joint output angle calculation model, and the virtual universal joint output angle calculation model, the phase angle of the actual universal joint output angle calculation model is set to an increase / decrease threshold. Correct according to. The phase angle of the actual universal joint output angle calculation model is corrected so that the neutral position of the steering wheel 32 and the neutral position of the steered wheel 24 are approximated.
Therefore, the phase angle of the actual universal joint output angle calculation model can be corrected according to the steering state of the steering wheel 32 by the driver and the model formulas for the actual universal joint and the virtual universal joint mounted on the vehicle. .

As a result, it becomes possible to estimate the phase difference of the rotation angle generated between the shafts connected using the actual universal joint. As a result, even when the steering angle changes while the ignition switch is off, the steered angle can be calculated according to the phase difference of the rotation angle.
Therefore, it is possible to improve the estimation accuracy of the actual turning angle and appropriately control the SBW system. In addition to this, even when an assembly error occurs in the members constituting the torque transmission path, it becomes possible to calculate the turning angle according to the assembly error, and improve the estimation accuracy of the actual turning angle. Thus, it becomes possible to appropriately control the SBW system.

(Modification)
(1) In this embodiment, the torque transmission path includes four actual universal joints (7, 11, 19, 23). However, the present invention is not limited to this, and the number of actual universal joints is, for example, Any number corresponding to the layout of the vehicle may be used.
In this case, for example, when both the steering-side universal joint and the steered-side universal joint are formed by only one universal joint, the steered angle of the steered wheels 24 is calculated using the following formula (17).

(2) In the present embodiment, the vehicle is configured to include the steering side clutch angle calculation unit 66, the steering side clutch angle calculation unit 68, the clutch angle deviation calculation unit 70, and the correction processing block 78. However, the present invention is limited to this. It is not a thing. That is, for example, after the vehicle is shipped, the steering side clutch angle, the steering side clutch angle, and the clutch are adjusted using the equipment outside the vehicle in a maintenance shop with both the current steering angle and the actual turning angle adjusted to the neutral position. An angular deviation may be calculated. In addition, the calculated clutch angle deviation may be input to the clutch angle deviation storage unit 72 by cable connection or the like, and the clutch angle deviation is stored via a storage medium such as a non-volatile memory. You may memorize | store in the part 72. FIG.

(3) In the present embodiment, the steering torque detector is formed by the pinion shaft torque sensor 46t, but the configuration of the steering torque detector is not limited to this. That is, for example, the steering torque detector may be formed by at least one of the steering torque sensor 36 and the steering motor torque sensor 2t. Here, when the steering torque detector 2t is formed by the steering motor torque sensor 2t, steering that is the torque that the driver is applying to the steering wheel 32 the steering motor torque detected by the steering motor torque sensor 2t. Process to convert to torque.

(4) In the present embodiment, in the process of calculating the steered side clutch angle θcl_out, the turning motor rotation angle at the time when the ignition switch is turned off is set as the reverse input angle tanθ _In of the universal joint 23 as described above. Entered in (2). However, the process for calculating the steered side clutch angle θcl_out is not limited to this.
That is, the value obtained by adding the offset component of the steered-side universal joint (19, 23) to the steered-motor universal angle (19, 23) at the time when the ignition switch is turned off is used as the reverse input angle tanθ _In of the universal joint 23 as described above. You may input into Formula (2).

(5) In the present embodiment, in the process of calculating the steering-side clutch angle θcl_out, the turning motor rotation angle at the time when the ignition switch is turned off is set as the reverse input angle tan θ _In of the universal joint 23 as described above. Entered in (2). However, the process for calculating the steered side clutch angle θcl_out is not limited to this.
That is, based on the torque sensor value Vtp and the torque sensor model, the torsion angles of the steered side shaft and the steered side universal joints (19, 23) are subtracted from the steered motor rotation angle when the ignition switch is turned off. The calculated value is calculated. Then, this calculated value may be input to the above equation (2) as the reverse input angle tan θ _In of the universal joint 23. The steered side shaft is the clutch output shaft 17, the steered side intermediate shaft 21, and the pinion shaft 25.

(6) In the present embodiment, the virtual universal joint UJD is disposed closer to the steered wheel 24 than the universal joint 23. However, the position where the virtual universal joint UJD is disposed is not limited thereto.
(7) In this embodiment, only one virtual universal joint UJD is arranged on the torque transmission path, but the number of virtual universal joints UJD arranged on the torque transmission path is not limited to one.
(8) In the present embodiment, the correlation map stored in the correlation map storage unit 80 shows the relationship between the joint angle αd of the virtual universal joint UJD and the virtual input / output angle deviation used in the calculation. It is not limited. That is, for example, a configuration may be used in which the relationship between the joint angle αd of the virtual universal joint UJD and the virtual input / output angle deviation used in the calculation is calculated using a mathematical formula stored in advance.

(9) In the present embodiment, the relationship between the maximum change width difference value and the correction joint angle is shown by the conversion map stored in the conversion map storage unit 82, but the present invention is not limited to this. In other words, for example, the relationship between the maximum change width difference value and the correction joint angle may be calculated using an equation.
(10) In the present embodiment, the virtual universal joint output angle calculation model is a model formula that shows the relationship between the angle obtained by adding the phase angle to the steered wheel side input angle, the steered wheel side output angle, and the joint angle α. However, the present invention is not limited to this. In other words, the virtual universal joint output angle calculation model may be a model formula indicating the relationship between the angle obtained by adding the phase angle to the steered wheel side input angle and the steered wheel side output angle.

(11) In the present embodiment, the range in which the current steering angle θH is changed in order to calculate the actual vehicle turning angle maximum value and the virtual turning angle maximum value is set in advance with a neutral position (0 [deg]) as a reference ± Although it is set within 180 [deg], it is not limited to this. That is, the range in which the current steering angle θH is changed to calculate the actual machine turning angle maximum value and the virtual turning angle maximum value is set to less than ± 180 [deg] with respect to the neutral position (0 [deg]). May be. Further, the range in which the current steering angle θH is changed to calculate the actual machine turning angle maximum value and the virtual turning angle maximum value is set to a range exceeding ± 180 [deg] with respect to the neutral position (0 [deg]). It may be set.
In this case, the range in which the current steering angle θH is changed is, for example, the maximum from the change in the actual machine input / output angle deviation when calculating the turning angle that changes according to the current steering angle θH in a state in which the steering angle is changed. A range in which at least one of the value and the minimum value can be calculated may be set (for example, see FIG. 12). This is, for example, a range within ± 90 [deg] with respect to the neutral position (0 [deg]).

(12) In this embodiment, the range in which the current steering angle θH is changed in order to calculate the actual input / output angle deviation maximum change width and the virtual input / output angle deviation maximum change width is set in advance to the neutral position (0 [deg]). However, the present invention is not limited to this. That is, the range in which the current steering angle θH is changed in order to calculate the actual input / output angle deviation maximum change width and the virtual input / output angle deviation maximum change width is ± 180 [deg] with respect to the neutral position (0 [deg]). You may set to less than. Further, a range in which the current steering angle θH is changed to calculate the actual input / output angle deviation maximum change width and the virtual input / output angle deviation maximum change width is ± 180 [deg] with respect to the neutral position (0 [deg]). You may set in the range exceeding.
In this case, the range in which the current steering angle θH is changed is, for example, the maximum from the change in the actual machine input / output angle deviation when calculating the turning angle that changes according to the current steering angle θH in a state in which the steering angle is changed. A range in which at least one of the value and the minimum value can be calculated may be set (for example, see FIG. 12). This is, for example, a range within ± 90 [deg] with respect to the neutral position (0 [deg]).

1 Steering control device for vehicle 2 Steering motor (steering actuator)
2t Steering motor torque sensor 4 Steering motor controller 6 Clutch 7, 11 Universal joint (steering side universal joint)
19, 23 Universal joint (steering side universal joint)
8 Reaction force motor (Reaction force actuator)
DESCRIPTION OF SYMBOLS 10 Reaction force motor control part 16 Steering motor angle sensor 24 Steering wheel 32 Steering wheel 34 Steering angle sensor 40 Clutch plate 42 Steering shaft 44 Pinion shaft 46 Pinion 46t Pinion shaft torque sensor 50 Vehicle speed sensor 52 Engine controller 54 Command calculating part 56 Anti-reverse Force servo control unit 58 Clutch control unit 60 Neutral position storage unit 62 Steering motor current command calculation unit 64 Clutch state switching unit 66 Steering side clutch angle calculation unit 68 Steering side clutch angle calculation unit 70 Clutch angle deviation calculation unit 72 Clutch angle Deviation storage section 74 Steering angle storage section 76 Steering angle calculation section 78 Correction processing block 80 Correlation map storage section 82 Conversion map storage section 84 Actual machine input / output angle deviation calculation section 86 Correction joint angle calculation section 88 Correction phase angle calculation Part 90 Steering side Clutch angle correction value calculation unit 92 Clutch angle deviation correction value calculation unit 94 Phase angle correction necessity determination unit 96 Correction command value output unit MA Steering side previous processing content storage unit MB Reaction force side previous processing content storage unit UJD Virtual universal joint

Claims (11)

A vehicle steering control device including an actual universal joint that connects a torque transmission path between a steering wheel and a steered wheel,
A steering angle detector for detecting a steering angle of the steering wheel;
A steering angle calculation unit that inputs the steering angle detected by the steering angle detection unit into a preset real machine universal joint output angle calculation model, and calculates a turning angle of the steered wheels;
An actual universal joint output angle calculation model correction unit for correcting the actual universal joint output angle calculation model, and steer control of the steered wheels according to the steering angle of the steering wheel,
The actual machine universal joint output angle calculation model correction unit adds the actual machine universal joint output angle calculation model to the actual machine universal joint output angle calculation model based on the steering angle, the actual machine universal joint output angle calculation model, and a preset virtual universal joint output angle calculation model. The actual turning angle maximum value that is the maximum value of the turning angle when the steering angle to be inputted is changed within a preset range, the virtual universal joint output angle calculation model, and the actual universal joint output angle calculation. A virtual turning angle maximum value that is a maximum value of the turning angle when the steering angle input to the model is changed within the preset range, and calculates the actual turning angle maximum value and the The correction phase angle and the correction joint angle are calculated by comparison with the maximum value of the virtual turning angle, and the correction phase angle and The correction joint angle calculates a correction necessity determination for input and output angle deviation with a decrease threshold and the steering angle set in advance and the steering angle for determining calculated using the actual steering angle maximum When the correction using the correction phase angle with respect to the phase angle of the actual universal joint output angle calculation model is determined by comparison with the input / output angle deviation for determining necessity of correction , the neutral position of the steering wheel The phase angle is corrected according to the increase / decrease threshold so that the neutral position of the steered wheel approximates,
In the actual universal joint output angle calculation model, the phase angle indicating the torsion angle of the output shaft with respect to the input shaft of the actual universal joint is added to the steering wheel side input angle that is an angle input from the steering wheel side to the actual universal joint. And a steered wheel side output angle, which is an angle output to the steered wheel side through the actual wheel universal joint, and the steered wheel side output angle.
The virtual universal joint output angle calculation model is a model formula different from the actual universal joint output angle calculation model, and is arranged in series with the actual universal joint to virtually calculate the torque transmission path together with the actual universal joint. An angle obtained by adding a phase angle indicating a torsion angle of the output shaft with respect to the input shaft of the virtual universal joint to the steering wheel side input angle that is an angle input from the steering wheel side to the virtual universal joint to be connected to the virtual universal joint; A vehicle steering control device, characterized in that it is a model equation showing a relationship with a steered wheel side output angle that is an angle obtained by outputting the steered wheel side input angle to the steered wheel side via a wheel.   The actual universal joint output angle calculation model correction unit includes a turning angle calculated by inputting the steering angle into the actual universal joint output angle calculation model, the virtual universal joint output angle calculation model, and the actual universal joint output angle. The phase angle of the actual universal joint output angle calculation model is corrected based on the turning angle calculated by inputting the steering angle to the calculation model and the increase / decrease threshold value. Vehicle steering control device. The actual universal joint output angle calculation model correction unit, when before Symbol actual steering angle maximum value is outside the range of the absolute value of the increase or decrease threshold set the virtual turning angle maximum value as a reference, the actual The vehicle steering control device according to claim 1, wherein the phase angle of the universal joint output angle calculation model is corrected according to the increase / decrease threshold. The torque transmission path is connected by a plurality of actual universal joints,
A virtual universal joint output angle calculation model correction unit that corrects the virtual universal joint output angle calculation model,
The virtual universal joint output angle calculation model includes an angle obtained by adding the phase angle to the steering wheel side input angle, the steered wheel side output angle, an input side axis and an output side axis of the virtual universal joint in plan view. A model formula showing the relationship between the joint angle, which is the angle formed by the axes,
The virtual universal joint output angle calculation model correction unit is based on the maximum and minimum values of the turning angle when the steering angle input to the actual universal joint output angle calculation model is changed within a preset range. The actual machine input / output angle deviation maximum change width, which is the change width, and the maximum and minimum values of the turning angle when the steering angle input to the virtual universal joint output angle calculation model is changed within the preset range. A virtual input / output angle deviation maximum change width that is a change width based on the value, and further, based on an absolute value of a difference between the actual machine input / output angle deviation maximum change width and the virtual input / output angle deviation maximum change width 4. The joint angle of the virtual universal joint output angle calculation model is corrected, according to any one of claims 1 to 3. Dual steering control device. The actual machine universal joint output angle calculation model correcting unit changes the steering angle input to the actual machine universal joint output angle calculation model within the preset range with respect to the neutral position, and then returns the steering angle to the neutral position. 5. The vehicle steering control device according to claim 4 , wherein the actual machine input / output angle deviation maximum change width is calculated based on a change width based on a maximum value and a minimum value of the turning angle at the time. The actual universal joint output angle calculation model correction unit changes the steering angle input to the actual universal joint output angle calculation model to the neutral position after changing the steering angle to the upper limit of the preset range with respect to the neutral position. Return, and further, based on the change range based on the maximum value and the minimum value of the turning angle when changing back to the neutral position after changing to the lower limit value of the preset range, the actual machine input / output angle deviation maximum the vehicle steering control apparatus according to claim 4 or claim 5, characterized in that to calculate the variation width. The actual machine universal joint output angle calculation model correction unit corrects the actual machine universal joint output angle calculation model by setting the position of the virtual universal joint closer to the steered wheels than the actual machine universal joint. The vehicle steering control device according to any one of claims 1 to 6 . The actual machine universal joint output angle calculation model correction unit is configured to set a universal joint set in advance from a change angle at which the steering angle input to the virtual universal joint and the actual machine universal joint output angle calculation model is changed via each universal joint. Based on the value obtained by subtracting the offset component of each universal joint calculated using the offset component calculation model, the virtual turning angle maximum value is calculated,
The universal joint offset component calculation model, said any one of claims 1 to 7, wherein which is a model expression indicating a phase angle indicating the torsion angle of the output shaft to the input shaft of each universal joint The vehicle steering control device described in 1. A clutch that switches between an open state that mechanically separates the torque transmission path and a connected state that mechanically connects the torque transmission path;
A turning actuator rotation angle detector that detects a turning actuator rotation angle that is a rotation angle of a turning actuator that controls the turning of the turning wheel;
Steering-side clutch angle calculation that calculates the steering-side clutch angle that is the rotation angle on the steering wheel side of the torque transmission path by inputting the steering angle detected by the steering angle detection unit to the actual universal joint output angle calculation model And
The turning wheel rotation angle detected by the turning actuator rotation angle detector is input to a preset real machine universal joint reverse output angle calculation model and virtual universal joint reverse output angle calculation model, and the steered wheels of the torque transmission path are input. A steered side clutch angle calculating unit for calculating a steered side clutch angle which is a rotation angle on the side,
A clutch angle deviation calculating unit that calculates a clutch angle deviation that is a deviation between the steering side clutch angle calculated by the steering side clutch angle calculating unit and the steering side clutch angle calculated by the steering side clutch angle calculating unit;
A virtual universal joint reverse output angle calculation model correction unit for correcting the virtual universal joint reverse output angle calculation model,
The steering angle calculation unit calculates the clutch angle deviation calculated by the clutch angle deviation calculation unit to the steering side clutch angle calculated by the steering side clutch angle calculation unit before the clutch in the connected state is switched to the released state. The turning angle of the steered wheels is calculated based on the change angle at which the steered side clutch angle for turning angle calculation obtained by adding is changed via the steered side universal joint,
The actual universal joint reverse output angle calculation model includes an angle obtained by subtracting the phase angle from a steered wheel side reverse input angle, which is an angle input from the steered wheel side to the steered side universal joint, and the steered side universal joint. Is a model formula showing the relationship with the steering wheel side reverse output angle, which is the angle at which the steered wheel side reverse input angle is output to the steering wheel side via
The virtual universal joint reverse output angle calculation model includes an angle obtained by subtracting the phase angle from a steered wheel side reverse input angle, which is an angle input from the steered wheel side to the virtual universal joint, and the steered side universal joint. And the steering wheel side reverse output angle, which is the angle at which the steered wheel side reverse input angle is output to the steering wheel side.
The virtual universal joint reverse output angle calculation model correction unit increases or decreases the phase angle of the virtual universal joint reverse output angle calculation model when the actual turning angle maximum value is outside the range of the absolute value of the increase / decrease threshold. The vehicle steering control device according to any one of claims 1 to 8 , wherein correction is performed according to a threshold value. A steering torque detector for detecting a steering torque that is a torque applied to the steering wheel;
The turning angle calculation unit calculates a twist angle of the torque transmission path calculated by using a preset torque sensor model for a change angle obtained by changing the steering angle detected by the steering angle detection unit via the actual universal joint. Based on the value corrected using, calculate the turning angle of the steered wheels,
The torque sensor model is a model equation showing the relationship between the steering torque detected by the steering torque detector, the torsional rigidity of the actual universal joint, and the torsional rigidity of the input shaft and output shaft of the actual universal joint. The vehicle steering control device according to any one of claims 1 to 9, wherein the vehicle steering control device is a vehicle steering control device. A vehicle steering control method in which a torque transmission path between a steering wheel and a steered wheel is connected by an actual universal joint, and the steered wheel is steered according to a steering angle of the steering wheel,
Detecting the steering angle of the steering wheel;
Based on the steering angle and the preset actual machine universal joint output angle calculation model and virtual universal joint output angle calculation model, the steering angle input to the actual machine universal joint output angle calculation model varies within a preset range. The actual turning angle maximum value that is the maximum turning angle of the steered wheels when the steering wheel is turned on, and the steering angle that is input to the virtual universal joint output angle calculation model and the actual universal joint output angle calculation model in advance. By calculating a virtual turning angle maximum value that is the maximum value of the turning angle when changed within a set range, and by comparing the actual turning angle maximum value with the virtual turning angle maximum value Steering for determination calculated by calculating the correction phase angle and the correction joint angle and using the correction phase angle and the correction joint angle Above using a steering angle and a preset decrease threshold calculating a correction necessity determination for input and output angle deviation, the actual by comparison with the actual steering angle maximum value and the correction necessity determination for input and output angle deviation and When the correction is determined to be necessary by using the correction phase angle relative to the phase angle of the universal joint output angle calculation model, the phase angle such that the neutral position of the steering wheel and the neutral position of the steered wheels is approximated Correct according to the increase / decrease threshold ,
Enter the steering angle the detected actual universal joint output angle calculation model correcting the phase angle, before calculating the Kiten steering angle,
In the actual universal joint output angle calculation model, the phase angle indicating the torsion angle of the output shaft with respect to the input shaft of the actual universal joint is added to the steering wheel side input angle that is an angle input from the steering wheel side to the actual universal joint. And a steered wheel side output angle, which is an angle output to the steered wheel side through the actual wheel universal joint, and the steered wheel side output angle.
The virtual universal joint output angle calculation model is a model formula different from the actual universal joint output angle calculation model, and is arranged in series with the actual universal joint to virtually calculate the torque transmission path together with the actual universal joint. An angle obtained by adding a phase angle indicating a torsion angle of the output shaft with respect to the input shaft of the virtual universal joint to the steering wheel side input angle that is an angle input from the steering wheel side to the virtual universal joint to be connected to the virtual universal joint; A vehicle steering control method, characterized in that it is a model formula showing a relationship with a steered wheel side output angle, which is an angle obtained by outputting the steered wheel side input angle to the steered wheel side via a wheel.

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