JP5983017B2 - Vehicle steering control device - Google Patents

Description

The present invention provides a steered wheel with a steered actuator such as a motor at a target steered angle according to the operation of the steering operator in a state where the torque transmission path between the steering operator and the steered wheel is mechanically separated. through it steers relates to a steering control equipment of the vehicle.

  Conventionally, with the torque transmission path between the steering operator (steering wheel) and the steered wheels mechanically separated, the steered wheels are turned to a target turning angle according to the operation of the steering operator. There is a steering control device that steers through a rudder actuator. Such a steering control device is a device that forms a system (SBW system) generally called a steer-by-wire (SBW: Steer By Wire, which may be described as “SBW” in the following description).

In the SBW system, the steering operation is continued in the same direction with the torque transmission path being mechanically separated, and when the steering operation reaches the vicinity of the cutting limit of the steering operation, the operation is performed via the steering operation. In some cases, a technique for giving a feeling of contact to a person is applied (see, for example, Patent Document 1).
In the technique described in Patent Document 1, when the turning angle of the steered wheels reaches the vicinity of the maximum turning angle, correction of the steering reaction force torque applied by the control of the steering reaction force is started. Then, control is performed to gradually increase the steering reaction force torque as time elapses from the time when correction of the steering reaction force torque is started.

JP 2006-240399 A

However, in the technique described in Patent Document 1, when the response of the steered wheels is delayed due to a sudden steering operation by the driver, the steering operator is idled until the steered angle reaches the vicinity of the maximum steered angle. After that, a steering reaction force is applied to the steering operator.
When the steering operator is switched back after the steering reaction force is applied to the steering operator, the steering operator idles to a certain angle. Further, there is a possibility that a problem that the turning of the steered wheels starts abruptly when the steering manipulator is turned back beyond the angle at which the steering reaction force rises during normal steering (end contact angle). There is.
The present invention was made in view of the problems described above, capable of suppressing the start of the rapid turning of the steered wheels occurs, to provide a steering control equipment of the vehicle With the goal.

In order to solve the above-described problem, in the present invention, when the steering angle of the steering operator exceeds a preset end contact angle with reference to the neutral position in a state where the backup clutch is switched to the released state, the steering motor Suspend the output of the steering torque. Then, when the steering angle of the steering operator beyond the end contact angle starts to decrease toward the neutral position, the output of the steering torque from the steering motor is resumed.
Further, when the steering angle of the steering operator beyond the end contact angle is increasing, it is estimated whether or not the increasing steering angle is equal to or greater than a preset engagement angle when the engagement completion time has elapsed. To do. In addition, if it is estimated that the increasing steering angle is greater than or equal to the engagement angle, a clutch engagement command is output to the backup clutch. The engagement completion time is an elapsed time from when the clutch engagement command for switching the backup clutch to the engagement state is output until the backup clutch is actually engaged.

According to the present invention, in a state where the steering angle of the steering operator increases from the neutral position and the output of the steering torque from the steering motor is interrupted, the steering angle of the steering operator exceeding the end contact angle is When the reduction toward the neutral position is started, the output of the turning torque from the turning motor is resumed.
For this reason, when the steering angle of the steering operator beyond the end contact angle starts to decrease toward the neutral position, it is possible to end the idling of the steering operator and start the turning of the steered wheels. Thus, it is possible to suppress the sudden start of the steered wheels. As a result, it is possible to reduce the possibility that the driver will feel uncomfortable in the steering operation of the steering operator.

1 is a diagram illustrating a schematic configuration of a vehicle including a steering control device according to a first embodiment of the present invention. It is a block diagram explaining the detailed structure of a steered motor control part. It is a flowchart which shows the process which the offset angle calculating part at the time of an end contact and a last turning command angle calculating part perform. It is a block diagram explaining the detailed structure of a reaction force motor control part. It is a time chart which shows an example of the operation | movement performed using the steering control apparatus which has the conventional structure. It is a time chart which shows an example of the operation | movement performed using the steering control apparatus of 1st embodiment of this invention. It is a figure which shows the modification of 1st embodiment of this invention, and is a time chart which shows an example of the operation | movement performed using the steering control apparatus of a modification. It is a flowchart which shows the process which the clutch control part with which the steering control apparatus of 2nd embodiment of this invention is provided. It is a time chart which shows an example of the operation | movement performed using the steering control apparatus of 2nd 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 (hereinafter referred to as the present embodiment) 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 according to the present embodiment (may be described as “steering control device” in the following description).
The vehicle provided with the steering control device 1 of the present embodiment is a vehicle to which the SBW system is applied.
Here, in the SBW system, the driving of the steered motor is controlled in accordance with the operation of a steering operator (steering wheel) that is steered by the driver of the vehicle, and the steered wheels are steered, thereby performing the vehicle progress Change direction. The drive control of the steered motor is performed by switching the backup clutch interposed between the steering operator and the steered wheels to the open state, which is the normal state, and setting the torque transmission path between the steering operator and the steered wheels to the machine. In a separate state.

For example, when an abnormality occurs in the SBW system, such as disconnection, the driver adds to the steering operator by switching the open backup clutch to the engaged state and mechanically connecting the torque transmission path. Use the force to continue turning the steered wheels.
As shown in FIG. 1, the steering control device 1 of the present embodiment includes a steered motor 2, a reaction force motor 4, and a backup clutch 6. In addition, the steering control device 1 includes a steering torque detector 8, a vehicle speed detector 10, a steering angle detector 12, a turning angle detector 14, and a controller 16.

The steered motor 2 is a motor that is driven in accordance with a steered motor command current output from a steered motor control unit 42 described later, and outputs steered torque for steered steered wheels W. The turning torque output by the turning motor 2 is transmitted to the rack gear 20 via the turning motor output shaft 18 that is rotated by driving the turning motor 2.
The rack gear 20 has a rack shaft 22 that is displaced in the vehicle width direction in accordance with the rotation of the steered motor output shaft 18. Both ends of the rack shaft 22 are connected to the steered wheels W via tie rods 24 and knuckle arms 26, respectively.

The tie rod 24 is a rod-shaped member that connects the end of the rack shaft 22 and the knuckle arm 26.
The knuckle arm 26 is a part that holds the steered wheels W, and attaches the steered wheels W via a hub (not shown). The knuckle arm 26 is attached to a vehicle body side member (not shown) such as a subframe using a suspension arm (not shown) and a shock absorber (not shown).

The steered wheels W are front wheels (left and right front wheels) of the vehicle, and are steered with the displacement of the rack shaft 22 in the vehicle width direction to change the traveling direction of the vehicle. In the present embodiment, a case where the steered wheels W are formed of left and right front wheels will be described. Accordingly, in FIG. 1, the steered wheel W formed with the left front wheel is denoted as steered wheel WFL, and the steered wheel W formed with the right front wheel is denoted as steered wheel WFR.
The reaction force motor 4 is disposed between the steering operator 28 and the backup clutch 6.

The reaction force motor 4 is a motor that is driven in response to a reaction force motor command current output from a reaction force motor control unit 44 described later, and applies a steering reaction force to the steering shaft 30 that forms part of the torque transmission path. Can be output. As a result, the reaction force motor 4 outputs a steering reaction force to the steering operator 28 via the steering shaft 30.
Here, the steering reaction force output from the reaction force motor 4 to the steering operator 28 switches the backup clutch 6 to the released state, and mechanically separates the torque transmission path between the steering operator 28 and the steered wheels W. This is the reaction force that can be output to the steering operator 28 in the state of being operated.

That is, the steering reaction force output from the reaction force motor 4 to the steering operator 28 is a reaction force acting in a direction opposite to the operation direction in which the driver steers the steering operator 28.
Further, the calculation of the steering reaction force is performed according to the tire axial force acting on the steered wheels W and the steering state of the steering operator 28. Thus, an appropriate steering reaction force is transmitted to the driver who steers the steering operator 28.
The backup clutch 6 is interposed between the steering operator 28 operated by the driver and the steered wheels W, and is switched to an open state or an engaged state according to a clutch command current output from a clutch control unit 40 described later. . Note that the backup clutch 6 is in an open state in a normal state.

  Here, when the state of the backup clutch 6 is switched to the released state, the one end side of the steering shaft 30 and the one end side of the pinion shaft 32 are separated. As a result, the torque transmission path between the steering operator 28 and the steered wheels W is mechanically separated so that the steering operation of the steering operator 28 is not transmitted to the steered wheels W. The steering shaft 30 has one end connected to the steering clutch plate 34 inside the backup clutch 6 and the other end connected to the steering operator 28 and rotates together with the steering operator 28. Further, one end of the pinion shaft 32 is connected to the steered side clutch plate 36 inside the backup clutch 6, and a pinion shaft side gear 38 provided on the other end side is engaged with the rack gear 20.

On the other hand, when the state of the backup clutch 6 is switched to the engaged state, one end side of the steering shaft 30 and one end side of the pinion shaft 32 are connected. As a result, the torque transmission path between the steering operator 28 and the steered wheels W is mechanically coupled so that the steering operation of the steering operator 28 is transmitted to the steered wheels W.
The steering torque detector 8 is provided, for example, in a steering column (not shown) that rotatably supports the steering operator 28 and detects the steering torque applied to the steering shaft 30 when the driver operates the steering operator 28. To do. Then, the steering torque detector 8 outputs an information signal including the detected steering torque to the controller 16. In the following description, the steering torque may be described as “torque sensor value Vts”.

Here, the steering torque applied to the steering shaft 30 when the driver operates the steering operator 28 is generated in a state where the backup clutch 6 is switched to the engaged state.
The vehicle speed detection unit 10 is a known vehicle speed sensor and detects the vehicle speed of the vehicle. Then, an information signal including the detected vehicle speed is output to the controller 16.
The steering angle detection unit 12 is formed by using, for example, a resolver, and is provided on the steering column like the steering torque detection unit 8.

Further, the steering angle detection unit 12 detects a current steering angle that is a current rotation angle (a steering operation amount) of the steering operator 28. Then, the steering angle detection unit 12 outputs an information signal including the detected current steering angle of the steering operator 28 to the controller 16. In the following description, the current steering angle may be described as “current steering angle θs”.
The turning angle detection unit 14 is formed using, for example, an encoder and is provided in the turning motor 2.

Further, the turning angle detection unit 14 detects the rotation angle (steering angle) of the turning motor 2. Then, the turning angle detection unit 14 outputs an information signal including the detected turning angle (may be described as “steering motor rotation angle” in the following description) to the controller 16. In the following description, the turning motor rotation angle may be described as “actual turning angle θt”.
The controller 16 includes, for example, a CPU (Central Processing Unit), and includes a clutch control unit 40, a steered motor control unit 42, and a reaction force motor control unit 44.

  The clutch control unit 40 calculates a clutch current command based on, for example, the temperature of the steered motor 2 and a preset clutch engagement temperature for the purpose of suppressing damage to the steered motor 2 or the like. This compares the temperature of the steering motor 2 with the clutch engagement temperature in a state where the backup clutch 6 is switched to the open state, and determines whether the temperature of the steering motor 2 exceeds the clutch engagement temperature.

When it is determined that the temperature of the steering motor 2 exceeds the clutch engagement temperature, a command signal (clutch engagement command) for switching the backup clutch 6 in the released state (normal state) to the engagement state is calculated, and the calculated command The signal is a clutch current command.
The clutch control unit 40 also calculates a command signal (clutch release command) for switching the engaged backup clutch 6 to the released state, for example, according to the temperature of the steering motor 2.

Here, the clutch engagement temperature is a temperature that is lower by a preset temperature difference than the use limit temperature at which it is difficult to normally use the steered motor 2 (normal state, normal control). The information is stored in the control unit 40. In addition, said use limit temperature is set using the rating preset to the steering motor 2, "JIS C 4003" etc., for example.
Then, the clutch control unit 40 outputs an information signal including the generated clutch command current to the backup clutch 6. Thereby, the clutch control unit 40 controls the state (open state or engaged state) of the backup clutch 6.

The steered motor control unit 42 causes the steered motor 2 to output a steered torque according to the target steered angle in a state where the backup clutch 6 is switched to an open state based on various input information signals. The steering motor 2 is drive-controlled. The detailed configuration of the steered motor control unit 42 will be described later.
Here, the target turning angle is the turning angle of the steered wheels W with respect to the operation of the steering operator 28.

The reaction force motor control unit 44 inputs and outputs information signals via the communication line with the steering motor control unit 42 and the vehicle speed detection unit 10.
The reaction force motor control unit 44 controls the reaction force motor 4 based on various information signals received. A detailed configuration of the reaction force motor control unit 44 will be described later.

(Detailed configuration of the steered motor control unit 42)
Hereinafter, the detailed configuration of the steered motor control unit 42 will be described with reference to FIG. 1 and FIG. 2 and FIG. 3, including the relationship with other configurations shown in FIG.
FIG. 2 is a block diagram illustrating a detailed configuration of the steered motor control unit 42.
As shown in FIG. 2, the steering motor control unit 42 includes an SBW steering command angle calculation unit 46, a steering command angular speed calculation unit 48, an offset angle calculation unit 50 at the time of end contact, and a final steering command angle. A calculation unit 52 and a steered position servo control unit 54 are provided.

  The SBW steering command angle calculation unit 46 receives the information signal output from the vehicle speed detection unit 10 and the information signal output from the steering angle detection unit 12. Then, the SBW steering command angle is calculated based on the vehicle speed included in the information signal output from the vehicle speed detection unit 10 and the current steering angle θs included in the information signal output from the steering angle detection unit 12.

  Here, the SBW steering command angle is used to calculate a target turning angle corresponding to the operation of the steering operator 28 by the driver, and to drive and control the steering motor 2 according to the calculated target turning angle. Current command value. The SBW steering command angle corresponds to a target steering angle according to the operation of the steering operator 28 in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated. In the following description, the SBW steering command angle may be described as “SBW steering command angle θpure” or “θpure”.

Further, the SBW steering command angle calculation unit 46 outputs an information signal including the calculated SBW steering command angle θpure to the steering command angular velocity calculation unit 48, the offset angle calculation unit 50 at the time of contact, and the final steering command angle. The result is output to the calculation unit 52.
The steering command angular velocity calculation unit 48 receives the input of the information signal output by the SBW steering command angle calculation unit 46. Then, the SBW steering command angle θpure included in the information signal output from the SBW steering command angle calculation unit 46 is differentiated to calculate the steering command angular velocity. In the following description, the steering command angular velocity may be described as “steering command angular velocity θ ′ pure” or “θ ′ pure”.

Further, the steering command angular velocity calculation unit 48 outputs an information signal including the calculated steering command angular velocity θ′pure to the offset angle calculation unit 50 at the time of contact.
The end-offset offset angle calculation unit 50 receives the information signal output by the SBW steering command angle calculation unit 46 and the information signal output by the steering command angular velocity calculation unit 48. Based on the SBW steering command angle θpure included in the information signal output from the SBW steering command angle calculation unit 46 and the steering command angular velocity θ′pure included in the information signal output from the steering command angular velocity calculation unit 48, Calculate the offset angle when applying. In the following description, the offset angle at end contact may be described as “offset angle at end contact θoffset” or “θoffset”.

Here, the calculated end-offset offset angle θoffset is clockwise (clockwise, the same applies hereinafter) or counterclockwise (counterclockwise) of the current steering angle θs included in the information signal output by the steering angle detector 12. The same applies to the following), and the steering angle exceeds the end contact angle.
In the following description, the end contact angle may be described as “end contact angle θmax” or “θmax”.

The end contact angle is an angle at which the steering reaction force rises during the steering operation of the steering operator 28 in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated.
The end contact angle includes a right end contact angle that is an angle at which the steering reaction force rises when the steering operator 28 is rotated clockwise, and a steering reaction force that is obtained when the steering operator 28 is rotated counterclockwise. Set the left edge contact angle, which is the angle at which is raised.

In the present embodiment, as an example, the angle from the neutral position of the right end contact angle (change amount of the steering angle) and the angle from the neutral position of the left end contact angle (change amount of the steering angle) are the same. The case will be described. In the following description, the right end contact angle is the positive (+) side, and the left end contact angle is the negative (−) side.
Also, the end contact offset angle calculation unit 50 outputs an information signal including the calculated end contact offset angle θoffset to the final turning command angle calculation unit 52.

  The final turning command angle calculation unit 52 receives an input of the information signal output by the SBW steering command angle calculation unit 46 and the information signal output by the offset angle calculation unit 50 at the end of contact. Then, based on the SBW steering command angle θpure included in the information signal output from the SBW steering command angle calculation unit 46 and the end-offset offset angle θoffset included in the information signal output from the end-offset offset angle calculation unit 50, the final The steering command angle is calculated. In the following description, the final steering command angle may be described as “final steering command angle θcommand” or “θcommand”.

Here, with reference to FIG. 1 and FIG. 2, processing performed by the end-offset offset angle calculation unit 50 and the final turning command angle calculation unit 52 will be described using FIG. 3.
FIG. 3 is a flowchart illustrating processing performed by the offset angle calculation unit 50 and the final turning command angle calculation unit 52 during end contact. Note that the routine of the flowchart shown in FIG. 3 is repeatedly performed every calculation cycle (for example, 5 [msec]).

When the flowchart shown in FIG. 3 is started (“START” in the figure), first, in step S101, based on the already calculated offset angle and the SBW steering command angle θpure, the following equation (1) is used for determination. A steered command angle θtmp is calculated.
Here, the already-calculated offset angle is the offset angle at the time of contact calculated in the previous process. In the following description, the already-calculated offset angle may be described as “already-calculated offset angle θ′offset” or “θ′offset”.
θtmp = θpure−θ′offset (1)

In step S101, when the determination turning command angle θtmp is calculated, the processing performed by the calculation units 50 and 52 proceeds to step S102.
In step S102, it is determined whether or not the determination steering command angle θtmp calculated in step S101 exceeds the right end contact angle. In addition, in step S102, it is determined based on the steering command angular velocity θ′pure whether or not the steering operator 28 is being steered clockwise.

In step S102, if it is determined that the steering command angle for determination θtmp exceeds the right end contact angle and the steering operator 28 is being turned clockwise (“Y” in the drawing), the calculation unit 50, The processing performed by 52 proceeds to step S103.
On the other hand, if it is determined in step S102 that the determination turning command angle θtmp is equal to or smaller than the right end contact angle (“N” in the drawing), the processing performed by the calculation units 50 and 52 proceeds to step S104. Similarly, in step S102, when it is determined that the steering operator 28 is not increasing clockwise ("N" in the figure), the processing performed by the calculation units 50 and 52 proceeds to step S104.

In step S103, the end-offset offset angle θoffset is calculated as the following equation (2).
θoffset = θpure−θmax (2)
When the offset angle θoffset at the time of end application is calculated in step S103, the processing performed by the calculation units 50 and 52 proceeds to step S110.
In step S104, it is determined whether the determination turning command angle θtmp calculated in step S101 exceeds the left end contact angle. In addition, in step S104, it is determined whether or not the steering operator 28 is being steered counterclockwise (added) based on the steering command angular velocity θ′pure.

In step S104, if it is determined that the steering command angle for determination θtmp exceeds the left end contact angle and the steering operator 28 is turning counterclockwise (“Y” shown in the figure), the calculation unit 50, The processing performed by 52 proceeds to step S105.
On the other hand, if it is determined in step S104 that the determination turning command angle θtmp is equal to or less than the left end contact angle (“N” in the figure), the processing performed by the calculation units 50 and 52 proceeds to step S106. Similarly, in step S104, when it is determined that the steering operator 28 is not turning counterclockwise ("N" in the figure), the processing performed by the calculation units 50 and 52 proceeds to step S106.

In step S105, the offset angle θoffset at the end contact is calculated as the following equation (3).
θoffset = θpure + θmax (3)
When the offset angle θoffset at the end contact is calculated in step S105, the processing performed by the calculation units 50 and 52 proceeds to step S110.
In step S106, it is determined in the process of step S102 whether or not the determination turning command angle θtmp exceeds the right end contact angle. In addition, in step S106, it is determined whether or not the steering operator 28 is steering counterclockwise. Whether or not the steering operator 28 is steering counterclockwise is determined with reference to the current steering angle θs included in the information signal output from the steering angle detector 12, for example.

In step S106, if it is determined in step S102 that the steering command angle for determination θtmp exceeds the right end contact angle and the steering operator 28 is steering counterclockwise ("Y" in the figure), The processing performed by the calculation units 50 and 52 proceeds to step S107.
On the other hand, when it is determined in step S106 that the determination steering command angle θtmp does not exceed the right end contact angle (“N” in the drawing) in the processing of step S102, the processing performed by the calculation units 50 and 52 is as follows. The process proceeds to step S108. Similarly, if it is determined in step S106 that the steering operator 28 is not steering counterclockwise ("N" shown in the figure), the processing performed by the calculation units 50 and 52 proceeds to step S108.

In step S107, the offset angle θoffset at the end contact is calculated as the following equation (4).
θoffset
= Θ′offset−f (| θ′pure |, | θ′offset |) (4)
Here, the calculation coefficient f is set according to the configuration of the vehicle including the steering control device 1 (for example, the rigidity of the steering operator 28 and the steering shaft 30).
If the offset angle θoffset at the time of end contact is calculated in step S107, the processing performed by the calculation units 50 and 52 proceeds to step S110.

  In step S108, it is determined whether or not the determination steering command angle θtmp exceeds the left end contact angle in the process of step S104. In addition, in step S108, it is determined whether or not the steering operator 28 is steering clockwise. The determination as to whether or not the steering operator 28 is steering clockwise is made with reference to the current steering angle θs included in the information signal output from the steering angle detector 12, for example.

When it is determined in step S108 that the steering command angle for determination θtmp exceeds the left end contact angle and the steering operator 28 is steering clockwise (“Y” in the figure) in the process of step S104, The processing performed by the calculation units 50 and 52 proceeds to step S109.
On the other hand, if it is determined in step S108 that the determination steering command angle θtmp does not exceed the left end contact angle (“N” in the drawing) in the processing of step S104, the processing performed by the calculation units 50 and 52 is as follows. The process proceeds to step S110. Similarly, if it is determined in step S108 that the steering operator 28 is not steering clockwise (“N” in the figure), the processing performed by the calculation units 50 and 52 proceeds to step S110.

Here, when the processing performed by the calculation units 50 and 52 shifts from step S108 to step S110, the offset angle θoffset at the end contact is calculated as the already calculated offset angle θ′offset.
In step S109, the end-offset offset angle θoffset is calculated as the following equation (5).
θoffset
= Θ′offset + f (| θ′pure |, | θ′offset |) (5)
If the offset angle θoffset at the time of end application is calculated in step S109, the processing performed by the calculation units 50 and 52 proceeds to step S110.

In step S110, the final steering command angle θcommand is calculated using the following equation (6).
θcommand = θpure−θoffset (6)
Here, when the process proceeds from step S103 to step S110, θoffset calculated as the above equation (2) is used as the θoffset used in the above equation (6). Further, the end-offset offset angle θoffset calculated as the above equation (2) is an angle obtained by subtracting the end-contact angle θmax from the SBW steering command angle θpure.

Therefore, when the process proceeds from step S103 to step S110, the final turning command angle θcommand calculated by the above equation (6) becomes the right end contact angle (+ θmax).
Further, when the process proceeds from step S105 to step S110, the θoffset calculated as the above equation (3) is used as the θoffset used in the above equation (6). Further, the end contact offset angle θoffset calculated as the above equation (3) is an angle obtained by adding the end contact angle θmax to the SBW steering command angle θpure.

Therefore, when the process proceeds from step S105 to step S110, the final turning command angle θcommand calculated by the above equation (6) is the left end contact angle (−θmax).
When the process proceeds from step S107 to step S110, the θoffset calculated as the above equation (4) is used as the θoffset used in the above equation (6). Further, the offset angle θoffset at the time of application calculated as the above equation (4) is an angle obtained by subtracting the value obtained by multiplying the absolute value of θ′pure and the absolute value of θ′offset by the calculation coefficient f from θ′offset. It is. Therefore, the offset angle θoffset at the time of end application calculated in step S107 becomes a value closer to the SBW steering command angle θpure as the steering command angular velocity θ′pure is higher.

Therefore, when the process proceeds from step S107 to step S110, the final steering command angle θcommand calculated by the above-described equation (6) increases from the right end contact angle side of the steering operator 28 as the steering command angular velocity θ′pure increases. The angle approaches the neutral position.
When the process proceeds from step S109 to step S110, the θoffset calculated as the above equation (5) is used as the θoffset used in the above equation (6). Further, the offset angle θoffset at the time of end application calculated as the above equation (5) is an angle obtained by adding a value obtained by multiplying the absolute value of θ′pure and the absolute value of θ′offset by the calculation coefficient f to θ′offset. It is. Accordingly, the offset angle θoffset at the time of end application calculated in step S109 becomes a value that approximates the SBW steering command angle θpure as the steering command angular velocity θ′pure increases.

Therefore, when the process proceeds from step S109 to step S110, the final turning command angle θcommand calculated by the above equation (6) increases from the left end contact angle side of the steering operator 28 as the turning command angular velocity θ′pure increases. The angle approaches the neutral position.
On the other hand, when the process proceeds from step S108 to step S110, θoffset used in the above equation (6) is set to the already-calculated offset angle θ′offset.

In step S110, when the final turning command angle θcommand is calculated, the processing performed by the end-offset offset angle calculation unit 50 and the final steering command angle calculation unit 52 ends (“END” in the drawing).
Further, as described above, the end contact offset angle calculation unit 50 calculates the end contact offset angle θoffset based on the SBW steering command angle θpure and the steering command angular velocity θ′pure. Thereby, the offset angle calculation part 50 at the time of abutting restrict | limits the maximum value of final steering command angle (theta) command to SBW steering command angle (theta) pure.

The steered position servo control unit 54 receives the information signal output from the final steered command angle calculation unit 52. Then, based on the final steering command angle θcommand included in the information signal output by the final steering command angle calculation unit 52, the steering command current is calculated.
Here, the steering command current calculated by the steering position servo control unit 54 is a command value corresponding to the steering motor command current for outputting the torque corresponding to the final steering command angle θcommand to the steered wheels W. .

Further, the steered position servo control unit 54 changes the voltage supplied to the steered motor 2 so that the steered motor command current corresponding to the calculated steered command current is input to the steered motor 2.
Further, the turning position servo control unit 54 receives the input of the information signal output from the turning angle detection unit 14. In addition to this, the steered position servo control unit 54 detects the steered motor command current finally output to the steered motor 2. The information signal output by the turning angle detection unit 14 and the turning motor command current finally output to the turning motor 2 are used for the calculation of the turning command current. Thereby, the turning position servo control unit 54 performs feedback control related to the calculation of the turning command current.

  As described above, the steered motor control unit 42 increases the steering angle of the steering operator 28 from the neutral position and exceeds the end contact angle (right end contact angle, left end contact angle) set based on the neutral position. And the output of the steering torque from the steering motor 2 is interrupted. In addition to this, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the output of the steering torque from the steering motor 2 is resumed.

  Further, the steered motor control unit 42 determines the degree of change in the steered angle of the steered wheels W with respect to the steered angle of the steering operator 28. The steering angle of the steerable operator 28 from the neutral position to the end contact angle (right end contact angle, left end Control is performed to make it smaller than a state where the angle is less than the contact angle. In this control, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position side, the end contact offset angle θoffset calculated by the end contact offset angle calculation unit 50 is “0”. ”Is performed until“

(Detailed structure of reaction force motor control unit 44)
Hereinafter, the configuration of the reaction force motor control unit 44 will be described with reference to FIGS. 1 to 3, including the relationship with other configurations shown in FIG. 4, using FIG. 4.
FIG. 4 is a block diagram illustrating a detailed configuration of the reaction force motor control unit 44.
As shown in FIG. 4, the reaction force motor control unit 44 includes an SBW reaction force command current calculation unit 56 and a reaction force command current servo control unit 58.
The SBW reaction force command current calculation unit 56 receives an input of an information signal output from the vehicle speed detection unit 10, an information signal output from the steering angle detection unit 12, and an information signal output from the turning angle detection unit 14. Then, the reaction force command current is calculated based on the vehicle speed included in the information signal output from the vehicle speed detection unit 10 and the current steering angle θs included in the information signal output from the steering angle detection unit 12.

Here, the reaction force command current is a current command value for driving and controlling the reaction force motor 4.
The reaction force command current is calculated by multiplying the actual turning angle θt by a preset reaction force motor gain, for example. Here, the reaction force motor gain is set in advance using the reaction force motor gain map. The reaction force motor gain map is a map that depends on the vehicle speed and the steering angle of the steering operator 28, and is formed in advance and stored in the SBW reaction force command current calculation unit 56.

The SBW reaction force command current calculation unit 56 also steers the steering shaft 30 when the actual turning angle θt included in the information signal received from the turning angle detection unit 14 has reached the end contact angle. The reaction force command current is calculated so that the reaction force is suddenly applied.
Then, the SBW reaction force command current calculation unit 56 outputs an information signal including the calculated reaction force command current to the reaction force command current servo control unit 58.

The reaction force command current servo control unit 58 receives the information signal output from the SBW reaction force command current calculation unit 56. The voltage supplied to the reaction force motor 4 is set so that the reaction force motor command current corresponding to the reaction force command current included in the information signal output by the SBW reaction force command current calculation unit 56 is input to the reaction force motor 4. Change.
Further, the reaction force command current servo control unit 58 detects the reaction force motor command current finally output to the reaction force motor 4. The reaction force motor command current finally output to the reaction force motor 4 is used to control the voltage supplied to the reaction force motor 4. Thereby, the feedback control regarding the voltage supplied to the reaction force command current servo control unit 58 reaction force motor 4 is performed.

(Operation)
Next, an example of an operation performed using the steering control device 1 of the present embodiment will be described with reference to FIGS. 1 to 4 and FIGS. 5 and 6.
FIG. 5 is a time chart showing an example of an operation performed using a steering control device having a conventional configuration. FIG. 6 is a time chart showing an example of an operation performed using the steering control device 1 of the present embodiment.
First, an example of an operation performed using a steering control device having a conventional configuration will be described with reference to FIG.

  The time chart shown in FIG. 5 shows that when the vehicle travels, the driver first sets the steering angle to the right-end contact angle while paying attention to the steering operator 28 so that the steering command angle changes at a constant angular velocity. It shows the operation to steer clockwise until it exceeds. Thereafter, the steering operator 28 that is steered clockwise until the steering angle exceeds the right end contact angle is steered counterclockwise until the steering angle passes the neutral position and exceeds the left end contact angle, and further to the neutral position. The operation until the steering angle is returned is shown. In FIG. 5, the SBW steering command angle θpure is indicated by a broken line, and the final steering command angle θcommand is indicated by a solid line.

  As shown in FIG. 5, the final turning command angle θcommand is the right end contact angle (+ θmax) in a range where the steering angle exceeds the right end contact angle. Therefore, in a range where the steering angle exceeds the right end contact angle, the turning angle of the steered wheels W becomes a constant angle corresponding to the right end contact angle (+ θmax). Similarly, the final turning command angle θcommand is the left end contact angle (−θmax) in a range where the steering angle exceeds the left end contact angle. Therefore, in a range where the steering angle exceeds the left end contact angle, the turning angle of the steered wheels W is a constant angle corresponding to the left end contact angle (−θmax).

  For this reason, from the time when the steering angle increases from the neutral position side and exceeds the right end contact angle (the time indicated by “t1” in the figure), the time when the steering angle beyond the right end contact angle becomes less than the right end contact angle. The turning angle of the steered wheels W does not change from the right end contact angle during the time (indicated by “t2” in the figure). That is, between the time point t1 and the time point t2, the final steering command angle θcommand does not become an angle corresponding to the SBW steering command angle θpure. For this reason, between the time point t1 and the time point t2, even if the steering operator 28 is steered, the steered wheels W are not steered, and the steering operator 28 idles ("handle idle" shown in the figure). It will be.

Then, at the time point t2, that is, at the moment when the steering angle that has exceeded the right end contact angle becomes less than the right end contact angle, the final turning command angle θcommand becomes an angle corresponding to the SBW steering command angle θpure. The turning angle changes abruptly ("abrupt turning start" shown in the figure).
Similarly, when the steering angle increases from the neutral position side and exceeds the left end contact angle (the time indicated by “t3” in the figure), the steering angle that exceeds the left end contact angle becomes less than the left end contact angle. The turning angle of the steered wheels W does not change from the left end contact angle during the time (indicated by “t4” in the figure). That is, between the time point t3 and the time point t4, similarly to the time point between the time point t1 and the time point t2, the steered wheel W is not steered even if the steering operation member 28 is steered, and the steering operation member 28 is idling (in the drawing). ("Handle idle running").

Then, at the time point t4, that is, at the moment when the steering angle that exceeds the left end contact angle becomes less than the left end contact angle, the steered angle of the steered wheels W changes abruptly as at the time point t2 (see “ Sudden steering start ”).
As described above, in a vehicle equipped with a steering control device having a conventional configuration, the steered wheels W suddenly turn at the moment when the steering angle that exceeds the end contact angle becomes less than the end contact angle. For this reason, in a vehicle including a steering control device having a conventional configuration, the driver may feel a strong sense of discomfort in the steering operation of the steering operator 28.

Next, an example of an operation performed using the steering control device 1 of the present embodiment will be described with reference to FIG.
The time chart shown in FIG. 6 shows the same operation as in FIG. In FIG. 6, as in FIG. 5, the SBW steering command angle θpure is indicated by a broken line, and the final steering command angle θcommand is indicated by a solid line. In FIG. 6, the offset angle θoffset at the end contact is indicated by a one-dot chain line.
In the present embodiment, the steering motor control unit 42 interrupts the drive control of the steering motor 2 when the steering angle of the steering operator 28 increases from the neutral position and exceeds the end contact angle.

  Therefore, as shown in FIG. 6, from the time when the steering angle increases from the neutral position side and exceeds the right end contact angle, the steering operator 28 that is steering clockwise is steered clockwise toward the neutral position side. The turning angle of the steered wheel W does not change from the right end contact angle in the range up to the time point when it is turned (turned back). In FIG. 6, the time when the steering angle increases from the neutral position side and exceeds the right end contact angle is indicated by “t5”, and the time when the steering operator 28 that is steering clockwise is steered to the neutral position side. This is indicated by “t6”.

That is, between the time point t5 and the time point t6, the final steering command angle θcommand does not become an angle corresponding to a change in the SBW steering command angle θpure. For this reason, between the time point t5 and the time point t6, even if the steering operator 28 is steered, the steered wheels W are not steered, and the steering operator 28 idles ("handle idle" shown in the figure). It will be.
Further, during the period from time t5 to time t6, the offset angle θoffset at the end contact increases in the positive (+) direction from “0” as the SBW steering command angle θpure increases in the positive (+) direction.

Here, in the present embodiment, when the steering motor control unit 42 starts to reduce the steering angle of the steering operator 28 beyond the end contact angle toward the neutral position side, the steering motor control unit 42 performs drive control of the steering motor 2. Resume.
Therefore, when the steering toward the neutral position side of the steering operator 28 is started at time t6, the offset angle θoffset at the end contact is set to “0” as the SBW steering command angle θpure decreases toward the neutral position. Decrease.

For this reason, when the steering operator 28 is steered to the neutral position side from time t6, the final steering command angle θcommand decreases to the neutral position side as the SBW steering command angle θpure decreases to the neutral position side. Thereby, the turning angle of the steered wheels W changes toward the neutral turning angle (the turning angle corresponding to the straight traveling state of the vehicle).
Therefore, at time t6, control for gradually changing the steered angle of the steered wheels W over time is started ("steering is gradually started at the time of return" shown in the figure).

Here, as shown in step S110 (see FIG. 3) described above, when the end-offset offset angle θoffset approaches “0”, the final steering command angle θcommand approaches the SBW steering command angle θpure.
When the final steering command angle θcommand becomes equal to the SBW steering command angle θpure (the time indicated by “t7” in the drawing), the end-offset offset angle θoffset becomes “0”. Thereby, at time t7, the final steering command angle θcommand and the SBW steering command angle θpure are equal.

  Further, in the present embodiment, the turning motor control unit 42 determines that the degree of change in the turning angle of the steered wheels W with respect to the steering angle of the steering operator 28 is changed from the neutral position to the end contact angle. The steered motor 2 is driven and controlled so as to be smaller than the time until it reaches. This drive control is performed from when the steering angle of the steering operation element 28 beyond the end contact angle starts to decrease toward the neutral position until the end contact offset angle θoffset becomes “0”.

For this reason, between the time point t6 and the time point t7, the steering angle of the steering operator 28 is within the range from the neutral position to the end contact angle, such as the state between the start of the operation and the time point t5. Compared to the state, the degree of change in the turning angle with respect to the steering angle is small.
In addition, from the time point t7 to the time point when the steering angle of the steering operation element 28 steered counterclockwise passes through the neutral position and exceeds the left end contact angle (the time point indicated by “t8” in the drawing), the end point The state where the offset angle θoffset at the time of application is maintained at “0”. As a result, from the time point t7 to the time point t8, the final steering command angle θcommand and the SBW steering command angle θpure are equal, and the ratio of the steering angle of the steering operator 28 and the steering angle of the steered wheels W (gear) Ratio) is the normal ratio.

For this reason, when the steering angle of the steering operator 28 steered counterclockwise from the time t7 becomes the neutral position, the turning angle of the steered wheels W becomes the neutral turning angle.
Then, in the range from the time point t8 to the time point when the steering operator 28 that is steering counterclockwise is steered clockwise (turned back) toward the neutral position (the time point indicated by “t9” in the drawing), The turning angle of the steered wheel W does not change from the left end contact angle.

That is, between the time point t8 and the time point t9, similarly to the time point between the time point t5 and the time point t6, even if the steering operator 28 is steered, the steered wheel W is not steered, and the steering operator 28 is idling (in the drawing). ("Handle idle running").
Further, during the period from the time point t8 to the time point t9, as the SBW steering command angle θpure increases in the negative (−) direction, the end-offset offset angle θoffset increases from “0” in the negative (−) direction.

Therefore, when the steering toward the neutral position side of the steering operator 28 is started at time t9, the offset angle θoffset at the end contact is “with the decrease to the neutral position side of the SBW steering command angle θpure, similarly to time t6. It decreases toward “0”.
Therefore, when the steering operator 28 is steered to the neutral position side from time t9, the final steering command angle θcommand decreases to the neutral position side as the SBW steering command angle θpure decreases to the neutral position side. Thereby, like the time t6, the turning angle of the steered wheels W changes toward the neutral turning angle.

Therefore, at time t9, similarly to time t6, control is started to gradually change the turning angle of the steered wheels W as time elapses ("steering starts gradually when turning back" in the figure).
When the final steering command angle θcommand becomes equal to the SBW steering command angle θpure (the time indicated by “t10” in the drawing), the end-offset offset angle θoffset becomes “0”. Thereby, at the time t10, as in the time t7, the final steering command angle θcommand and the SBW steering command angle θpure are equal.

Further, in the same way from the time point t9 to the time point t10, as compared with the time point from the time point t6 to the time point t7, compared with the state in which the steering angle of the steering operator 28 is within the range from the neutral position to the end contact angle. The change degree of the turning angle with respect to the steering angle becomes small.
Further, when the steering angle of the steering operation element 28 steered clockwise from the time point t10 reaches the neutral position, the offset angle θoffset at the time of end contact is between the turning angle of the steered wheels W and the neutral turning angle. The state of “0” is maintained. As a result, from the time point t10 until the steering angle of the steering operator 28 reaches the neutral position, the final steering command angle θcommand and the SBW steering command angle θpure are equal, and the steering angle of the steering operator 28 and the steered wheels are equal. The ratio of W to the turning angle (gear ratio) is a normal ratio.

As described above, in the vehicle including the steering control device 1 of the present embodiment, it is possible to shorten the time during which the steering operator 28 idles as compared with the vehicle including the steering control device having the conventional configuration. . In addition to this, when the steering operator 28 whose steering angle exceeds the end contact angle starts to steer toward the neutral position side, the steering angle of the steered wheels W is gradually changed over time. Start.
For this reason, in the vehicle provided with the steering control device 1 of the present embodiment, unlike the vehicle provided with the steering control device having the conventional configuration, the steered wheels W are not rapidly steered, and the steering operator 28 In the steering operation, it is possible to reduce the possibility that the driver will feel uncomfortable.

  As described above, in the steering control method implemented by the operation of the steering control device 1 of the present embodiment, the steering torque corresponding to the target turning angle is changed while the backup clutch 6 is switched to the released state. Output from the rudder motor 2 to steer the steered wheels W. When the steering angle of the steering operator 28 increases from the neutral position and exceeds the end contact angle set with the neutral position as a reference, the output of the steering torque from the steering motor 2 is interrupted. Furthermore, when the steering angle exceeding the end contact angle starts to decrease toward the neutral position, the output of the turning torque from the turning motor 2 is resumed.

(Effects of the first embodiment)
In the present embodiment, the following effects can be obtained.
(1) When the steering motor control unit 42 increases the steering angle of the steering operator 28 from the neutral position and exceeds the end contact angle set with the neutral position as a reference, the steering torque of the steering motor 2 is increased. Interrupt output. Then, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the output of the steering torque from the steering motor 2 is resumed.

For this reason, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the idling of the steering operator 28 is terminated and the turning of the steered wheels W is started. Thus, it is possible to suppress the sudden start of the steered wheels W.
As a result, it is possible to reduce the possibility that the driver will feel uncomfortable in the steering operation of the steering operator 28 that is performed in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated. .

(2) The steered motor control unit 42 determines the degree of change in the steered angle of the steered wheels W relative to the steered angle of the steering operator 28 from the state where the steering angle of the steering operator 28 is less than the end contact angle from the neutral position. The control is also performed to make it smaller. In this control, the end-offset offset angle θoffset calculated by the end-offset offset angle calculation unit 50 is 0 from the time when the steering angle of the steering operator 28 beyond the end-contact angle starts to decrease toward the neutral position. Perform until the state becomes.

Therefore, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the steering operator 28 resumes the output of the steering torque from the steering motor 2, thereby the steering operator 28. The deviation generated between the neutral position and the neutral turning angle of the steered wheels W can be reduced.
As a result, it is possible to reduce the possibility that the driver will feel uncomfortable in the steering operation of the steering operator 28 that is performed in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated. .

(3) In the steering control method of the present embodiment, the steered wheels W are steered by outputting the steered torque corresponding to the target steered angle from the steered motor 2 while the backup clutch 6 is switched to the opened state. Let When the steering angle of the steering operator 28 increases from the neutral position and exceeds the end contact angle set with the neutral position as a reference, the output of the steering torque from the steering motor 2 is interrupted. Furthermore, when the steering angle exceeding the end contact angle starts to decrease toward the neutral position, the output of the turning torque from the turning motor 2 is resumed.

For this reason, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the idling of the steering operator 28 is terminated and the turning of the steered wheels W is started. Thus, it is possible to suppress the sudden start of the steered wheels W.
As a result, it is possible to reduce the possibility that the driver will feel uncomfortable in the steering operation of the steering operator 28 that is performed in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated. .

(Modification)
(1) In the present embodiment, the steered motor control unit 42 indicates the degree of change in the steered angle of the steered wheels W with respect to the steered angle of the steering operator 28, and the steering angle of the steering operator 28 from the neutral position to the end contact angle. Control to make it smaller than the state of less than is performed. In addition, this control is performed when the end-offset offset angle θoffset calculated by the end-offset offset angle calculation unit 50 from the time when the steering angle of the steering operator 28 beyond the end-contact angle starts to decrease toward the neutral position side. It is performed in a state until it becomes zero.

  However, the configuration of the steered motor control unit 42 is not limited to the above configuration, and the configuration of the steered motor control unit 42 may be configured to perform control A and control B described below.

(Control A)
Control is performed such that the degree of change in the turning angle of the steered wheels W relative to the steering angle of the steering operator 28 is equal to the degree of change in which the steering angle of the steering operator 28 is less than the end contact angle from the neutral position. This control is performed in a state from when the steering angle of the steering operation element 28 beyond the end contact angle starts to decrease toward the neutral position to the preset gear ratio change steering angle.

(Control B)
Control is performed so that the degree of change in the turning angle of the steered wheels W with respect to the steering angle of the steering operator 28 is smaller than the state in which the steering angle of the steering operator 28 is less than the end contact angle from the neutral position. This control is performed in a state from the time when the steering angle of the steering operator 28 becomes the gear ratio change steering angle to the neutral position.

Here, as shown in FIG. 7, the gear ratio change steering angle is an angle larger than the end contact angle, and is set according to, for example, the steering performance / steering characteristics of the vehicle. 42 is stored. FIG. 7 is a diagram illustrating a modification of the present embodiment, and is a time chart illustrating an example of an operation performed using the steering control device 1 of the modification of the present embodiment.
When the structure of the steered motor control unit 42 is configured to perform the above-described control A and control B, the following effects can be achieved.

That is, when the steering angle of the steering operator 28 beyond the end contact angle starts to decrease toward the neutral position, the output of the steering torque from the steering motor 2 is restarted, whereby the steering operator 28 The deviation generated between the neutral position and the neutral turning angle of the steered wheels W can be reduced.
As a result, it is possible to reduce the possibility that the driver will feel uncomfortable in the steering operation of the steering operator 28 that is performed in a state where the backup clutch 6 is switched to the released state and the torque transmission path is mechanically separated. .

(Second embodiment)
Hereinafter, a second embodiment of the present invention (hereinafter referred to as the present embodiment) will be described with reference to FIGS. 1 to 7 and FIGS. 8 and 9. In addition, since this embodiment is the structure similar to 1st embodiment mentioned above except the structure of the clutch control part 40, description other than the clutch control part 40 is abbreviate | omitted. Moreover, about the structure similar to 1st embodiment mentioned above, the same code | symbol is attached | subjected and demonstrated.

(Constitution)
FIG. 8 is a flowchart showing processing performed by the clutch control unit 40.
When the flowchart shown in FIG. 8 is started (“START” shown in the figure), first, in step S201, it is determined whether or not the steering angle of the steering operator 28 is increasing beyond the right end contact angle. In addition, in step S201, it is determined whether or not the increasing steering angle is equal to or greater than the right engagement angle when the engagement completion time has elapsed. In addition, in step S201, it is determined whether or not the steering operator 28 is steering clockwise (increase).

Here, the engagement completion time is an elapsed time from when the clutch control unit 40 outputs a clutch engagement command for switching the backup clutch 6 to the engagement state until the backup clutch 6 is actually engaged. Further, the engagement completion time is set according to the configuration and performance of the backup clutch 6 and stored in the clutch control unit 40.
Further, the right engagement angle is larger than the right end contact angle, and is set according to the turning performance and turning characteristics of the vehicle and stored in the clutch control unit 40, for example.

Further, when the completion time of the engagement has elapsed, whether or not the increasing steering angle is equal to or greater than the right engagement angle is determined using, for example, the following equation (7).
θlock ≦ θpure + T × θ′pure (7)
In the above equation (7), the right fastening angle is indicated by “θlock (+ θlock)”, and the fastening completion time is indicated by “T”.
Whether the steering operator 28 is steering clockwise (increase) is determined using, for example, the following equation (8).
θ'pure ≧ 0 (8)
That is, in step S201, it is estimated whether or not the steering command angle has reached the right engagement angle and the steering operation element 28 has been increased clockwise by T seconds after outputting the clutch engagement command.

In step S201, the steering command angle reaches the right engagement angle T seconds after the clutch engagement command is output, and the steering operator 28 is increased clockwise ("Y" in the figure). If it determines, the process which the clutch control part 40 performs will transfer to step S202.
On the other hand, in step S201, if it is determined that the steering command angle has not reached the right engagement angle ("N" in the figure) T seconds after outputting the clutch engagement command, the process performed by the clutch control unit 40 is as follows. The process proceeds to step S203. Similarly, in step S201, when it is determined that the steering operator 28 is not turning clockwise ("N" in the drawing), the processing performed by the clutch control unit 40 proceeds to step S203.

In step S202, an information signal including a clutch command current generated as a clutch engagement command is output to the backup clutch 6.
In this embodiment, as an example, as the steering angular velocity of the steering operator 28 during the engagement completion time increases, the clutch engagement command is sent to the backup clutch 6 when the steering angle of the steering operator 28 beyond the end contact angle is smaller. A case of outputting will be described.

In step S202, when the information signal including the clutch command current generated as the clutch engagement command is output to the backup clutch 6, the process performed by the clutch control unit 40 ends (“END” in the drawing).
In step S203, it is determined whether the steering angle of the steering operator 28 is increasing beyond the left end contact angle. In addition, in step S203, it is determined whether or not the increasing steering angle is equal to or greater than the left engagement angle when the engagement completion time has elapsed. In addition, in step S203, it is determined whether or not the steering operator 28 is steering counterclockwise.

Here, the left engagement angle is larger than the left end contact angle, and is set according to the turning performance and turning characteristics of the vehicle, for example, and stored in the clutch control unit 40.
Further, when the engagement completion time has elapsed, whether or not the increasing steering angle is equal to or greater than the left engagement angle is determined using, for example, the following equation (9).
−θlock ≧ θpure + T × θ′pure (9)
In the above formula (9), the left fastening angle is indicated by “−θlock”.

Further, whether or not the steering operator 28 is steered counterclockwise (added) is determined using, for example, the following equation (10).
θ′pure ≦ 0 (10)
That is, in step S203, it is estimated whether or not the steering command angle has reached the left engagement angle and the steering operator 28 has been turned counterclockwise T seconds after the clutch engagement command is output.

In step S203, T seconds after the clutch engagement command is output, the steering command angle reaches the left engagement angle, and the steering operator 28 is increased counterclockwise ("Y" shown in the figure). If it determines, the process which the clutch control part 40 performs will transfer to step S202.
On the other hand, if it is determined in step S203 that the steering command angle has not reached the left engagement angle ("N" shown in the figure) T seconds after outputting the clutch engagement command, the processing performed by the clutch control unit 40 is as follows. The process proceeds to step S204. Similarly, if it is determined in step S203 that the steering operator 28 is not turning counterclockwise ("N" in the figure), the processing performed by the clutch control unit 40 proceeds to step S204.

In step S <b> 204, an information signal including the clutch command current generated as the clutch release command is output to the backup clutch 6.
In step S204, when the information signal including the clutch command current generated as the clutch release command is output to the backup clutch 6, the process performed by the clutch control unit 40 is ended (“END” in the drawing).

As described above, in the process performed in step S201, when the steering angle of the steering operator clasp 28 exceeding the end contact angle is increasing, the increasing steering angle when the engagement completion time has elapsed is: This corresponds to a steering angle estimation unit that estimates whether or not it is greater than or equal to a preset engagement angle.
Similarly, the process performed in step S203 corresponds to the steering angle estimation unit.
The processing performed in step S202 corresponds to an engagement command output unit that outputs a clutch engagement command to the backup clutch 6 when the steering angle estimation unit estimates that the increasing steering angle is equal to or greater than the engagement angle.
Further, in the processing performed in step S202, as the steering angular velocity of the steering operator 28 during the engagement completion time is higher, a clutch engagement command is sent to the backup clutch 6 when the steering angle of the steering operator 28 beyond the end contact angle is smaller. Corresponds to the fastening command output section to output.

(Operation)
Next, an example of an operation performed using the steering control device 1 of the present embodiment will be described with reference to FIGS. 1 to 8 and FIG.
FIG. 9 is a time chart showing an example of an operation performed using the steering control device 1 of the present embodiment.
The time chart shown in FIG. 9 shows that when the vehicle is running, the driver steers the steering element 28 until the steering angle exceeds the end contact angle, and then the steering operation until the steering angle becomes less than the end contact angle. Then, again, the operation of performing the steering operation until the steering angle exceeds the end contact angle is shown. In FIG. 9, the SBW steering command angle θpure is indicated by a solid line, and the clutch command current is indicated by a one-dot chain line.

As shown between time t11 and time t12 in the figure, when it is determined that the SBW steering command angle θpure increasing beyond the end contact angle θmax is equal to or greater than the engagement angle after T seconds, the clutch command current is Switch from the release command to the clutch engagement command.
Further, as shown from time point 13 to time point t14 in the figure, when it is determined that the SBW steering command angle θpure that exceeds the end contact angle θmax is less than the engagement angle after T seconds, the clutch command current is Keep open command.

Further, as shown between time t15 and time t16 in the figure, when it is determined that the SBW steering command angle θpure increasing beyond the end contact angle θmax is equal to or greater than the engagement angle after T seconds, the clutch command current Is switched from the clutch release command to the clutch engagement command.
Here, in this embodiment, the higher the steering angular velocity of the steering operator 28 during the engagement completion time, the lower the steering angle of the steering operator 28 beyond the end contact angle, and the clutch engagement command to the backup clutch 6. Output.

  For this reason, in the present embodiment, the clutch command current is switched from the clutch release command to the clutch engagement command at the time t15 when the steering angle of the steering operator 28 that exceeds the end contact angle from the time t11 is smaller, and the clutch engagement command is backed up. Output to the clutch 6. In the figure, the steering angular velocity of the steering operator 28 during the fastening completion time is indicated by a broken line as the amount of change in the SBW steering command angle θpure with respect to the elapsed time.

(Effect of the second embodiment)
If it is the vehicle control apparatus 1 of this embodiment, in addition to the effect show | played by 1st embodiment mentioned above, it will become possible to show the effect described below.
(1) When the steering angle estimating unit is increasing the steering angle of the steering operator 28 beyond the end contact angle, the increasing steering angle is equal to or greater than the engagement angle when the engagement completion time has elapsed. When estimated, the engagement command output unit outputs a clutch engagement command to the backup clutch 6.
Therefore, the backup clutch 6 is not switched to the engaged state in a state where the reaction force motor 4 can output a sufficient steering reaction force to the steering operator 28 via the steering shaft 30.

  As a result, it is possible to suppress the generation of noise when switching the opened backup clutch 6 to the engaged state. In addition to this, when the steering operation element 28 is abruptly steered, the disengaged backup clutch 6 is switched to the engaged state, so that a state in which the steering angle is the end contact angle can be transmitted to the driver. It becomes possible.

(2) When the steering command output unit has a higher steering angular velocity of the steering operator 28 during the engagement completion time, the clutch engagement command is issued when the steering angle of the steering operator 28 beyond the end contact angle is smaller. Output to.
For this reason, regardless of the steering command angular velocity θ′pure, it is possible to suppress variations that occur in the SBW steering command angle θpure when the backup clutch 6 in the released state is actually engaged.
As a result, after the backup clutch 6 is in the engaged state, it is possible to suppress variations that occur in the degree of change in the turning angle of the steered wheels W with respect to the steering angle of the steering operator 28. Thereby, in the steering operation of the steering operator 28, it is possible to reduce the possibility that the driver will feel uncomfortable.

DESCRIPTION OF SYMBOLS 1 Steering control apparatus 2 Steering motor 4 Reaction force motor 6 Backup clutch 8 Steering torque detection part 10 Vehicle speed detection part 12 Steering angle detection part 14 Steering angle detection part 16 Controller 18 Steering motor output shaft 20 Rack gear 22 Rack shaft 24 Tie rod 26 Knuckle arm 28 Steering operator 30 Steering shaft 32 Pinion shaft 34 Steering side clutch plate 36 Steering side clutch plate 38 Pinion shaft side gear 40 Clutch control unit 42 Steering motor control unit 44 Reaction force motor control unit 46 SBW steering command Angle calculation unit 48 Steering command angular velocity calculation unit 50 Offset angle calculation unit at end contact 52 Final steering command angle calculation unit 54 Steering position servo control unit 56 SBW reaction force command current calculation unit 58 Reaction force command current servo control unit W Steering wheel (WFL, WFR)

Claims (2)

A steering motor for steering the steered wheels;
A backup clutch capable of switching between an open state in which a torque transmission path between a steering operator operated by a driver and the steered wheels is mechanically separated and an engagement state in which the torque transmission path is mechanically coupled; ,
A clutch control unit for switching the backup clutch to an engaged state or an opened state;
A steering motor control unit that outputs a steering torque according to a target steering angle with respect to the operation of the steering operator in a state where the backup clutch is switched to an open state, and
The steered motor control unit interrupts output of the steered torque from the steered motor when the steering angle of the steering operator exceeds a preset end contact angle with respect to a neutral position, and the end contact angle When the steering angle of the steering operator exceeding the value starts to decrease toward the neutral position, the output of the steering torque from the steering motor is resumed ,
The clutch control unit outputs a clutch engagement command for switching the backup clutch to an engaged state when the steering angle of the steering operator exceeding the end contact angle is increasing, and then the backup clutch is actually engaged. A steering angle estimation unit that estimates whether or not the increasing steering angle is equal to or greater than a preset engagement angle at the time when the engagement completion time, which is the elapsed time until the state is reached, and the steering angle estimation unit, When the steering angle during the increase is estimated to be the fastening angle than, the steering control apparatus for a vehicle for the engagement command output unit, wherein Rukoto provided with outputting the clutch engagement command to the backup clutch. The engagement command output unit outputs the clutch engagement command when the steering angle of the steering operator exceeding the end contact angle is smaller as the steering angular velocity of the steering operator is higher during the engagement completion time. The vehicle steering control device according to claim 1 , wherein the vehicle steering control device is output to the vehicle.

Images