JP5840168B2 - Vehicle steering system - Google Patents

Description

  The present invention relates to a vehicle steering apparatus used when changing the traveling direction of a vehicle to a desired direction.

  In recent vehicles, a Steer By Wire type steering system (hereinafter sometimes referred to as an SBW system) that transmits a driver's steering intention to an electric signal through an electric wire is converted into an electric signal. Some have been adopted. In such an SBW system, the direction and amount of operation of the steering handle by the driver are converted into electrical signals on the side of the steering device, and provided to the steering device including the steering motor. In response to this, the steering device operates to steer the steering wheel in accordance with the driver's steering intention by driving the steering motor in accordance with the electric signal.

  In such an SBW system, an abnormal connection of a backup clutch (hereinafter referred to as “connecting device”) that performs an operation of connecting or disconnecting the rotating shaft on the steering device side and the rotating shaft on the steering device side occurs. If steer-by-wire control is continuously performed in this state, the steering handle may be taken off.

  This will be described. When steer-by-wire control is continuously performed in a state where the coupling device is erroneously coupled, the steering motor is driven so that the actual turning angle follows the command turning angle. At this time, since the steering handle and the steering wheel are mechanically coupled via the coupling device, the steering handle is rotated according to the steering operation of the steering wheel, and the command steering angle changes. End up. As a result, the deviation between the command turning angle and the actual turning angle is not reduced, and the turning torque is increased, which may cause a phenomenon that the steering handle is taken.

As one approach for solving the above-mentioned problem, for example, in Patent Document 1, a connection device connection determination unit that determines whether or not a connection device is connected, and a disconnection command are output to the connection device. A vehicle steering control device is disclosed that includes control switching means for switching from steer-by-wire control to assist (steering force assist) control when it is determined that the coupling device is connected.
According to the vehicle steering control device according to Patent Document 1, it is possible to suppress the phenomenon that the steering handle is taken due to the coupling abnormality of the coupling device.

JP 2007-137294 A

  However, in the vehicle steering control device according to Patent Document 1, the state determination as to whether the coupling device is in the coupled state or the disconnected state is performed based on the actual steering angular velocity calculated from the actual steering angle and the actual turning angle. Since a configuration (see paragraph 0022 of Patent Document 1) that is performed based on whether or not the deviation from the turning angular velocity is equal to or less than a predetermined value is adopted, for example, the vehicle is connected in a traveling scene in which a steering operation hardly occurs, for example, when traveling straight ahead. It becomes difficult to determine the state of the apparatus.

  As described above, in a traveling scene where it is difficult to determine the state of the coupling device, it may happen that a case where it is necessary to switch from steer-by-wire control to assist (steering force assist) control may be overlooked. In this case, there is a concern that the phenomenon that the steering handle is pulled due to the coupling abnormality of the coupling device cannot be suppressed.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to appropriately prevent the steering handle from being taken off due to a coupling abnormality of the coupling device.

In order to achieve the above object, the invention according to (1) includes a reaction force application device that generates an operation input of a steering member by a driver, a turning device for turning a steering wheel, and the reaction force application. A coupling device that performs an operation of bringing the device and the turning device into a mechanically coupled state or a separated state, a steering reaction force actuator that applies a steering reaction force to the reaction force applying device, and the steering A steering actuator that applies a steering torque to the device, an information acquisition unit that acquires information on whether the connecting device is in a coupled state or a disconnected state, the reaction force applying device, the steering device, A control unit that performs operation control of the coupling device, the steering reaction force actuator, and the steering actuator, and the control unit is configured to control the steering member when the coupling device is in a disconnected state. The turning angle depends on the operation state A steer-by-wire control mode for driving the steering reaction force actuator so as to apply a steering reaction force according to the steering state of the steering device, and the coupling device is in a coupled state The steering control mode driving at least one of the steering reaction force actuator and the steering actuator so as to reduce the operation torque of the steering member by the driver, The steer-by-wire control mode includes a gear ratio variable steer-by-wire control mode in which the specific stroke is variable according to changes in vehicle speed, and a gear ratio fixed steer-by-wire control mode in which the specific stroke is fixed regardless of changes in vehicle speed. Despite the output of a disconnection command that puts the coupling device in a disconnected state When the information indicating that the coupling device is in a coupled state by the information acquiring unit is acquired, the steering function mode is switched from the variable gear ratio steer-by-wire control mode to steer-by-wire control mode of the gear ratio fixing The most important feature is to perform control.

In the invention according to (1), the case where the coupling device is in the coupled state even when the disconnection command for outputting the coupling device is output is the case where the coupling device is in an abnormal state. Is assumed. In such a case, when the steering function mode is switched from, for example, the steer-by-wire control mode (variable gear ratio) to the assist control mode, the load on the coupling device may become excessive, and the durability of the coupling device may be impaired. .
Therefore, in the invention according to (1), the steering function mode is changed from the steer-by-wire control mode with a variable gear ratio to a fixed gear ratio when the coupling device is in the coupled state even though the disconnection command is output. The configuration for performing control to switch to the steer-by-wire control mode was adopted.

According to the invention according to (1) , the steering function mode is changed from the steer-by-wire control mode with a variable gear ratio to a fixed gear ratio when the coupling device is in the coupled state even though the disconnection command is output. Therefore, the vehicle steering apparatus according to the present invention is in a self-steering state, steering lock, while preventing an excessive load from being applied to a coupling device that is likely to be in an abnormal state. A situation that falls into a state or a steer-free state can be avoided as much as possible.

  The invention according to (2) is the vehicle steering device according to (1), in which the coupling device sets the mechanical force between the reaction force applying device and the steered device. It further includes a detection unit that detects an operation to make the separated state, and the information acquisition unit acquires information on whether the coupling device is in a coupled state or a disconnected state via the detection unit. It is characterized by that.

  In the vehicle steering control device according to Patent Document 1, the state determination as to whether the connecting device is in the coupled state or the disconnected state is made based on the actual steering angular velocity and the actual rotation calculated from the actual steering angle and the actual turning angle. Since the configuration is based on whether or not the deviation from the rudder angular velocity is less than or equal to a predetermined value, it is difficult to determine the state of the connecting device in a traveling scene where steering operation hardly occurs, for example, when traveling straight ahead. there were.

  In this regard, according to the invention according to (2), the connecting device has a detection unit that detects an operation of bringing the reaction force applying device and the steering device into a mechanically coupled state or a separated state. Therefore, regardless of whether or not the steering member is being operated by the driver, it is possible to acquire information as to whether the coupling device is in the coupled state or the disconnected state.

  In addition, according to the invention according to (2), since it is possible to acquire information on whether the coupling device is in the coupled state or the disconnected state via the detection unit included in the coupling device, Even at the time of start-up where a coupling abnormality tends to occur, it is possible to accurately grasp whether the coupling device is in the coupled state or the disconnected state. As a result, the phenomenon that the steering member is removed due to the coupling abnormality of the coupling device can be prevented more appropriately.

  According to the vehicle steering device of the present invention, it is possible to appropriately prevent the steering handle from being pulled due to the coupling device coupling abnormality.

It is a lineblock diagram showing the outline of the steering device for vehicles concerning the embodiment of the present invention. It is an arrow cross-sectional view which follows the AA line showing the disconnection state of a coupling device. It is an arrow cross-sectional view which follows the AA line showing the disconnection state of a coupling device. It is a longitudinal cross-sectional view showing the coupling | bonding state of a coupling device. It is a longitudinal cross-sectional view showing the coupling | bonding state of a coupling device. It is a flowchart figure which uses for description of the basic operation | movement of the steering apparatus for vehicles which concerns on embodiment of this invention. It is a flowchart figure showing the flow of a processing of the subroutine program concerning active VGS (Active Variable Gear ratio Steering). It is a flowchart figure showing the flow of processing of a subroutine program concerning active VGS1 (Active Variable Gear ratio Steering 1). It is a flowchart figure showing the flow of processing of a subroutine program concerning active VGS2 (Active Variable Gear ratio Steering 2). It is a flowchart figure showing the flow of processing of a subroutine program concerning active VGS3 (Active Variable Gear ratio Steering 3). It is a flowchart figure showing the flow of processing of a subroutine program concerning VGS (Variable Gear ratio Steering). It is a flowchart figure showing the flow of processing of the subroutine program concerning EPS (Electric PowerSteering). It is a flowchart figure showing the flow of processing of a subroutine program concerning manual steering (Manual Steering). It is a flowchart figure with which it uses for description of the initialization operation | movement of the steering apparatus for vehicles which concerns on embodiment of this invention. It is a flowchart figure with which it uses for description of the initialization operation | movement of the steering apparatus for vehicles which concerns on embodiment of this invention. It is a flowchart figure with which it uses for description of the coupling device abnormality diagnosis process which the vehicle steering device which concerns on embodiment of this invention performs. It is a flowchart figure with which it uses for description of the coupling device abnormality diagnosis process which the vehicle steering device which concerns on embodiment of this invention performs. It is a flowchart figure with which it uses for description of the coupling device abnormality diagnosis process which the steering device for vehicles which concerns on other embodiment of this invention performs. FIG. 17 is a flowchart for explaining a basic operation of a vehicle steering apparatus according to another embodiment shown in FIG. 16. It is explanatory drawing which represents the difference of the effect of the steering apparatus for vehicles which concerns on an Example, and the steering apparatus for vehicles which concerns on a comparative example by contrast.

Hereinafter, a vehicle steering apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram illustrating an outline of a vehicle steering apparatus 101 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA showing the disconnected state of the coupling device 4. FIG. 3 is a longitudinal cross-sectional view illustrating the disconnected state of the coupling device 4. FIG. 4 is a cross-sectional view taken along the line AA showing the coupled state of the coupling device 4. FIG. 5 is a vertical cross-sectional view illustrating the coupling state of the coupling device 4.

  As shown in FIG. 1, a vehicle steering apparatus 101 according to an embodiment of the present invention includes a steering handle (steering wheel) 1, a reaction force applying apparatus 2, a steering apparatus 3, a coupling apparatus 4, such as a CAN (Controller Area). Network), a vehicle speed sensor 6 for detecting a vehicle speed (vehicle speed), a yaw rate sensor 7, a lateral acceleration sensor 8, and a rack position sensor 39.

  The steering handle 1 corresponding to the “steering member” of the present invention is used when changing the traveling direction of a vehicle (not shown) to a desired direction. A steering shaft 10 is connected to the central portion of the steering handle 1.

  The reaction force applying device 2 has a function of applying a reaction force with respect to the rotation direction of the steering shaft 10. The steering shaft 10 is connected to a second rotating shaft 40 of the connecting device 4 described later via the first universal joint 11. The steering shaft 10 is rotatably supported by first to third bearings 13, 14, 15 provided at intervals in the interior of the case 12. The inside of the case 12 is kept liquid-tight. A steering torque sensor 16, a steering angle sensor 17, and a reaction force generator 18 are provided on the steering shaft 10.

  The steering torque sensor 16 has a function of detecting the magnitude and direction of the steering torque input from the steering handle 1 using, for example, solenoid type coils 12a and 12b. Steering torque signals SA and SB detected by the coils 12a and 12b as changes in magnetic permeability have mutually contradictory characteristics (the added values of the steering torque signals SA and SB are constant). The steering torque signals SA and SB are input to the interface circuit 164. In the interface circuit 164, the waveforms of the steering torque signals SA and SB are shaped by amplification and filter processing. The steering torque signals SA and SB after waveform shaping are input to each of a first control device 353, a second control device 363, and a third control device 393, which will be described later, via the communication medium 5.

  In the first to third control devices 353, 363, 393, the added value of the steering torque signals SA, SB is calculated. Here, the added value of the steering torque signals SA and SB always takes a constant value when the steering torque sensor 16 is normal. This is because the steering torque signals SA and SB detected by the steering torque sensor 16 have mutually opposite characteristics. This means that an abnormality diagnosis of the steering torque sensor 16 can be performed based on whether or not the added value of the steering torque signals SA and SB takes a constant value. In addition, when one of the steering torque signals SA and SB changes rapidly, there is a high probability that a coil disconnection or a circuit component abnormality has occurred.

  Therefore, the first to third control devices 353, 363, 393 monitor the steering torque signals SA, SB, or monitor the change in time of each single value, thereby diagnosing abnormality of the steering torque sensor 16 ( (Including abnormality diagnosis relating to whether or not a coil breakage or circuit component abnormality has occurred).

  The steering angle sensor 17 has a function of detecting the steering angle and direction input from the steering handle 1 using, for example, a pair of rotation angle sensors (not shown) such as two potentiometers. The configuration of the steering angle sensor 17 will be described in detail. The steering shaft 10 is provided with a small gear 174 that is rotatable around the steering shaft 10 as shown in FIG. The small gear 174 is provided with a large gear 175 that meshes with the small gear 174. The pair of rotation angle sensors housed in the case 173 detect rotation angle signals SC and SD (both equivalent signals) related to the steering of the steering handle 1 that has been decelerated by detecting the rotation angle of the large gear 175, respectively. Output. The rotation angle signals SC and SD are input to a first control device 353, a second control device 363, and a third control device 393, which will be described later, via the communication medium 5.

  The first to third control devices 353, 363, and 393 have a function of performing an abnormality diagnosis related to whether or not the steering angle sensor 17 is abnormal by monitoring a comparison result between the rotation angle signals SC and SD. The rotation angle signals SC and SD have common characteristics when the steering angle sensor 17 is normal. This means that an abnormality diagnosis relating to whether or not the steering angle sensor 17 is abnormal can be performed based on whether or not the comparison results between the rotation angle signals SC and SD match.

  Therefore, the first to third control devices 353, 363, and 393 can perform abnormality diagnosis related to whether or not the steering angle sensor 17 is abnormal by monitoring the comparison result between the rotation angle signals SC and SD. it can.

  The reaction force generator 18 has a function of generating a reaction force with respect to the rotation direction of the steering shaft 10 of the steering handle 1. The reaction force generation device 18 is provided on a third worm wheel 180 provided so as to rotate together with the steering shaft 10 and a rotation shaft of the third motor 181, and is engaged with the third worm wheel 180. 3 worms 182 and a third control device 393.

  The third control device 393 is provided with a third current sensor (third current detection unit) 184 </ b> A that detects a third current value flowing through the third motor 181. The third current value detected by the third current sensor 184A is sent by the third control device 393 to each of the first control device 353 and the second control device 363 via the communication medium 5.

  The third control device 393, which will be described in detail later, is used for steering, which will be described later, based on the steering torque signals SA and SB of the steering torque sensor 16 and the rotation angle signals SC and SD of the steering angle sensor 17. The first motor 332 and the second motor 342 and a function of generating a control signal for driving and controlling the third motor 181 for applying the steering reaction force are provided. However, the third control device 393 may be configured by omitting the function of generating a control signal for driving and controlling the first motor 332 or the second motor 342.

  The steered device 3 meshes with a rack shaft 32 connected to a pair of steering wheels 30a and 30b in the vehicle width direction via tie rods 31a and 31b, and a first rack tooth 320 provided on the rack shaft 32. A first pinion gear 33; a first gear shaft 330 provided with one end of the first pinion gear 33; a second pinion gear 34 engaged with a second rack tooth 321 provided on the rack shaft 32; A second gear shaft 340 provided with two pinion gears 34 at one end, a first drive device 35 for driving the first gear shaft 330, and a second drive device for driving the second gear shaft 340. 36.

  The first gear shaft 330 is connected to one first rotating shaft 38 extending from the connecting device 4 via the second universal joint 37. The other second rotating shaft 40 extending from the connecting device 4 is connected to the steering shaft 10 via the first universal joint 11. The configuration of the coupling device 4 will be described later in detail.

  A pair of rack position sensors 39 that detect the position of the rack shaft 32 in the axial direction are provided between one side of the rack shaft 32 (left side as viewed in the drawing) and the housing 378 that covers components such as the rack shaft 32. Is provided. The rack position sensor 39 is configured by providing a pair of sensors (not shown) such as two potentiometers in a case 390. The position detection signals of the pair of rack position sensors 39 are sent directly to the first to third control devices 353, 363, and 393 via the communication medium 5, respectively. Further, the first control device 353 sends one position detection signal of the pair of rack position sensors 39 to the second control device 353 and the third control device 363 via the communication medium 5. Also good. Further, the second control device 363 sends the other position detection signal of the pair of rack position sensors 39 to each of the first control device 353 and the third control device 393 via the communication medium 5. Also good. The opening of the housing 378 is liquid-tightly held by a combination of dust seals 381a and 381b and an oil seal 382.

  The first drive device 35 includes a first worm wheel 331 and a first worm (not shown) that meshes with the first worm wheel 331. The first gear shaft 330 provided with the first worm wheel 331 and the first pinion gear 33 is supported at three points with respect to the housing 378 via bearings 350, 351 and 352. The first worm is provided on the rotation shaft of the first motor 332. As a result, when the rotation shaft of the first motor 332 is driven, the first gear shaft 330 is rotationally driven via the first worm and the first worm wheel 331. Then, as a result of the first pinion gear 33 being rotationally driven, the rack shaft 32 operates so as to be driven in the axial direction.

  The second drive device 36 includes a second worm wheel 341 and a second worm (not shown) that meshes with the second worm wheel 341. The second gear shaft 340 provided with the second worm wheel 341 and the second pinion gear 34 is supported at three points with respect to the housing 378 via bearings 360, 361 and 362. The second worm is provided on the rotation shaft of the second motor 342. As a result, when the rotation shaft of the second motor 342 is driven, the second gear shaft 340 is rotationally driven via the second worm and the second worm wheel 341. Then, as a result of the second pinion gear 34 being rotationally driven, the rack shaft 32 operates in the axial direction as in the example of the first driving device 35.

  The rack shaft 32, the first pinion gear 33, the second pinion gear 34, the first drive device 35, and the second drive device 36 constitute a “steering force transmission mechanism”.

  The first control device 353 is provided with a first current sensor (first current detection unit) 332A that detects a first current value flowing through the first motor 332. The first current value detected by the first current sensor 332A is sent by the first control device 353 to each of the second control device 363 and the third control device 393 via the communication medium 5.

  The first control device 353 includes an interface circuit for data input / output, a computer for control calculation, a watchdog timer circuit for abnormality diagnosis, and an FET bridge circuit for driving the first motor 332. Etc.).

  The first control device 353 is connected to a power source 184 via a series circuit of a fuse (not shown) and a first parent relay 354. Further, the first control device 353 is connected to the first motor 332 via the first child relay 355. Therefore, the control unit (not shown) of the first control device 353 opens the respective contacts of the first parent relay 354 and the first child relay 355 at the time of abnormality diagnosis of the first current sensor 332A, for example. By performing this control, the power supply to the first motor 332, the first control device 353, and the coupling device 4 is surely cut off.

  The control unit of the first control device 353 (and the second control device 363 and the third control device 393) calculates the target position of the rack shaft 32 and the rack shaft detected by the rack position sensor 39. The feedback control is performed so that the current position of 32 matches the target position of the rack shaft 32 obtained by calculation.

  During this feedback control, the first control device 353 (and the second control device 362 and the third control device 393) having the “abnormality diagnosis unit” detects the first current sensor 332A. Is compared with a second current value detected by a second current sensor 342A, which will be described later, and it is determined whether or not the deviation between the first and second current values exceeds a predetermined threshold value. To do. Here, when the required turning operation of the steering wheel is normally performed, a current having a balanced magnitude flows through each of the first motor 332 and the second motor 342. This is because the electric characteristics of the first motor 332 and the second motor 342 are set in common with each other, in other words, the electric characteristics are the same in the normal operating range. This is because processing in the control device is set as appropriate, and the rotation shafts of the first motor 332 and the second motor 342 are connected to each other via the “steering force transmission mechanism”. .

Therefore, the abnormality diagnosing unit of the first control device 353 only monitors the deviation between the first current value and the second current value, and does not require complicated diagnosis processing and standby time. And the second motor 342 and their drive circuits (the first control device 353 and the second control device 363) can be quickly diagnosed. In addition, when the rack position sensor 39 is abnormal (when one of the pair of sensors 39 is abnormal), the first current value and the second current value are not required to move the rack shaft 32. Since the deviation becomes large, the abnormality diagnosis unit of the first control device 353 can perform abnormality diagnosis of the rack position sensor 39 by monitoring this value. In short, the abnormality diagnosis of the rack position sensor 39 can be quickly performed without moving the steering wheels 30a and 30b.
Note that the abnormality diagnosis function of the first current sensor 332A or the second current sensor 342A included in the first control device 353 is similarly provided in the second control device 363 and the third control device 393. It is configured. Therefore, the second control device 363 and the third control device 393 are also configured to include an abnormality diagnosis unit similar to the first control device 353.

  When a diagnosis that at least one of the first current sensor 332A and the second current sensor 342A is abnormal is made, the control unit of the first control device 353 cuts off the power supply to the coupling device 4 Control. Thereby, the pair of first rotating shaft 38 and second rotating shaft 40 extending from the coupling device 4 are mechanically coupled, and the steering shaft 10 and the first rotating shaft 38 are mechanically coupled with each other. .

  In addition, the control unit of the first control device 353 determines that at least one of the first current sensor 332A and the second current sensor 342A is abnormal, The energization is interrupted by a relay (not shown) to connect the first rotary shaft 38 and the second rotary shaft 40, and at the same time, control is performed to open the respective contacts of the first parent relay 354 and the first child relay 355. Thus, the power supply to the first motor 332 and the first control device 353 is operated to be surely cut off.

  At the same time as the above, the control unit of the second control device 363 determines that the second current sensor 332A or the second current sensor 342A is abnormal when at least one of the first current sensor 332A and the second current sensor 342A is abnormal. By performing control to open the respective contacts of the parent relay 364 and the second child relay 365, the power supply to the second motor 342 and the second control device 363 is reliably cut off, and the coupling device 4 is operated by a relay (not shown) to connect the first rotary shaft 38 and the second rotary shaft 40.

  At the same time as described above, the control unit of the third control device 393 that functions as a part of the reaction force generation device 18 at the normal time changes the steering function mode indicating the setting state of the steering function to the electric power steering (Electric Power Steering: Hereinafter, it is abbreviated as “EPS”.) The function is reconfigured to perform (continue) the EPS assist control for reducing the steering torque of the steering handle 1 (see Table 1).

  Similar to the first control device 353, the second control device 363 is provided with a second current sensor (second current detection unit) 342A that detects a second current value flowing through the second motor 342. It has been. The second current value detected by the second current sensor 342A is sent by the second control device 363 to each of the first control device 353 and the third control device 393 via the communication medium 5.

  Similarly to the first control device 353, the second control device 363 drives an interface circuit for data input / output, a computer for control calculation, a watchdog timer circuit for abnormality diagnosis, and a second motor 342. For example, an FET bridge circuit (not shown) is included.

  The second control device 363 is connected to a power source 184 via a series circuit of a fuse (not shown) and a second parent relay 364. Further, the second control device 363 is connected to the second motor 342 via the second slave relay 365. Therefore, for example, the control unit of the second control device 363 sets a threshold value at which the deviation of the signals of the first current sensor 332A and the second current sensor 342A is determined in advance when the second motor 342 falls into an abnormal state. At the time of abnormality diagnosis exceeding, the second motor 342, the second control device 363, and the coupling device 4 are controlled by opening the respective contacts of the second parent relay 364 and the second child relay 365. The operation is performed so as to connect the first rotating shaft 38 and the second rotating shaft 40 by interrupting the power supply to the power supply by a relay (not shown).

  The control unit of the second control device 363 (and the first control device 353 and the third control device 393) calculates the target position of the rack shaft 32 and the rack shaft detected by the rack position sensor 39. The feedback control is performed so that the current position of 32 matches the target position of the rack shaft 32 obtained by calculation.

  During this feedback control, the abnormality diagnosis unit of the second control device 363 uses the first current value detected by the first current sensor 332A and the second current detected by the second current sensor 342A. A deviation from the value is obtained by calculation, and it is determined whether or not the difference between the obtained first and second current values exceeds a predetermined threshold value. Here, when the required turning process is normally performed on the assumption that the characteristics of the first motor 332 and the second motor 342 are set in common, the first motor 332 and the second motor 332 Each of the motors 342 has a current having a substantially balanced magnitude. The reason is the same as described above.

  Then, based on the determination result relating to whether or not the difference between the first and second current values exceeds the threshold value, the abnormality diagnosis unit of the second control device 363 uses the signal of the first current sensor 332A or the first It can be seen that an abnormality diagnosis relating to whether at least one of the signals of the current sensor 342A of the second current sensor 342A is abnormal can be performed.

  Therefore, the abnormality diagnosis unit of the second control device 363 monitors the determination result related to whether or not the difference between the first and second current values exceeds the threshold value, whereby the signal of the first current sensor 332A, Alternatively, abnormality diagnosis relating to whether or not at least one of the signals of the second current sensor 342A is abnormal can be performed.

  When a diagnosis that at least one of the signal of the first current sensor 332A and the signal of the second current sensor 342A is abnormal is made, the control unit of the second control device 363 Control to cut off the power supply to the coupling device 4 is performed by the illustrated relay. Thereby, a pair of 1st rotating shaft 38 and the 2nd rotating shaft 40 extended from the connection apparatus 4 are couple | bonded, and the steering shaft 10 and the 1st rotating shaft 38 are connected with this.

  In addition, the control unit of the second control device 363 makes a diagnosis that at least one of the signal of the first current sensor 332A and the signal of the second current sensor 342A is abnormal. , The power supply to the second motor 342 and the second control device 363 is surely cut off by performing control to open the respective contacts of the second parent relay 364 and the second child relay 365. To work.

  At the same time, the control unit of the first control device 353 diagnoses that at least one of the signal of the first current sensor 332A and the signal of the second current sensor 342A is abnormal. In this case, it is possible to reliably supply power to the first motor 332 and the first control device 353 by performing control to open the respective contacts of the first parent relay 354 and the first child relay 355. Operates to shut off.

At the same time, the control unit of the third control device 393 that functions as a part of the reaction force generation device 18 at the normal time reconfigures the steering function mode indicating the setting state of the steering function into the EPS function. Then, control is performed such that EPS assist control for reducing the steering torque of the steering handle 1 is executed (continued) (see Table 1).
Note that ““ ”in Table 1 indicates a steering function mode (VGS1 in this example) set by reconstructing the steering system when a single abnormality occurs, for example, when an abnormality occurs only in the steering torque sensor 16. . Also, “◯” in Table 1 indicates that the steering system has been reconfigured when multiple abnormalities occur, that is, when abnormality occurs in the third current sensor 184A or the yaw rate sensor 7 after the steering torque sensor 16 is abnormal, for example. The steering function mode to be set (VGS in this example) is shown. In Table 1, “x” indicates various sensors 6, 7, 8, 16, 17, 39, 332 A, 342 A, 184 A, or first to third motors 332, 342, 181, first to first 3 shows a steering function mode that cannot be set by reconstructing the steering system when an abnormality occurs in any of the various functional units including the three control devices 353, 363, and 393.

  The control unit of the third control device 393 includes a vehicle speed signal from the vehicle speed sensor 6, a signal from the yaw rate sensor 7, a signal from the lateral acceleration sensor 8, a signal from the steering torque sensor 16, a signal from the steering angle sensor 17, and a rack position sensor 39. The third motor 181 is mainly driven and controlled based on the above signal. The abnormality diagnosis unit of the third control device 393 performs abnormality diagnosis by comparing the control signals generated in the first to third control devices 353, 363, and 393, and identifies the abnormality diagnosis location. To do. Then, the control unit of the third control device 393 reconstructs the steering system in consideration of the combination of the remaining normal parts excluding the specified abnormality diagnosis part, and performs appropriate steering as will be described in detail later. It operates to select the function mode and execute the necessary control.

  More specifically, the third control device 393 includes an interface circuit for data input / output, a computer for control calculation, a watchdog timer circuit for abnormality diagnosis, and an FET bridge circuit for driving the third motor 181. (Both not shown) and the like.

The third control device 393 is connected to the power source 184 via a series circuit of a fuse (not shown) and a third parent relay 185. Further, the third control device 393 is connected to the third motor 181 via the third child relay 186. Accordingly, the control unit of the third control device 393, for example, when the diagnosis that both the steering torque sensor 16 and the steering angle sensor 17 are abnormal is made, the third parent relay 185 and the third child. By performing control to open the respective contacts of the relay 186, the power supply to the third motor 181, the third control device 393, and the coupling device 4 is surely cut off. In this case, the control unit of the third control device 393 connects the first rotating shaft 38 and the first rotating shaft 38 by connecting the first rotating shaft 38 and the second rotating shaft 40 by the connecting device 4. Thus, the steering function mode is set to manual steering.
However, the configuration of the third parent relay 185 and the third child relay 186 can be omitted when the third control device 393 functions as an overall control device for the entire steering system.

  By the way, for example, when an abnormality diagnosis of the steering torque sensor 16 is made (see Table 1), the control unit of the third control device 393 controls the steering angle and direction based on the rotation angle signals SC and SD of the steering angle sensor 17. Control for causing the third motor 181 to generate a steering reaction force according to the control is executed. In order to notify the driver that an abnormality has occurred in the steering torque sensor 16 during this control, the control unit of the third control device 393 displays a warning and also displays the steering torque as compared with the normal time. Control to increase (heavy).

  The control unit of the third control device 393 calculates the third target current value to be given to the third motor 181 and calculates the third current current value detected by the third current sensor 184A. The feedback control is performed so as to coincide with the third target current value obtained by the above.

  When an abnormality occurs in the signal of the third current sensor 184A (see Table 1), the control unit of the third control device 393 determines the third target current value obtained by the calculation of the third motor 181. Control is performed using the converted voltage signal instead of the terminal voltage signal. Also during this control, the control unit of the third control device 393 displays a warning to notify the driver that an abnormality has occurred in the signal of the third current sensor 184A, and at the normal time. The steering torque is increased (heavy) as compared with the control.

  Further, when an abnormality occurs in at least one of the third motor 181 and the third control device 393 (see Table 1), the steering angle and direction based on the rotation angle signals SC and SD of the steering angle sensor 17. In addition, while referring to the current position of the rack shaft 32 detected by the rack position sensor 39, a warning is displayed to notify the driver that an abnormality has occurred, and is larger than that during normal steering ( The drive control of the first motor 332 and the second motor 342 is executed by using the control units of the first control device 353 and the second control device 363 so that the gear ratio becomes slow. . During this drive control, the control unit of the third control device 393 performs control to open the respective contacts of the third parent relay 185 and the third child relay 186, whereby the third motor 181, And the power supply to the 3rd control apparatus 393 is interrupted | blocked reliably.

  The connecting device 4 includes a first rotating shaft 38 (see FIGS. 3 and 5) connected to the steering device 3 side and a second rotating shaft 40 (see FIG. 3) connected to the reaction force applying device 2 side. 2 to FIG. 5), and has a function of switching to any one of a coupled state and a disconnected state. As shown in FIGS. 3 and 5, the first rotating shaft 38 is rotatably supported with respect to the case 45 via a four-point contact bearing (which may be a double-row angular bearing) 381. The second rotating shaft 40 is rotatably supported by the case 45 via a bearing 401 and is also rotatably supported by the first rotating shaft 38 via a bearing 405.

  A substantially cylindrical recess 383 is provided on the reaction force applying device 2 side of the first rotating shaft 38. On the other hand, a substantially cylindrical shaft portion 403 is provided on the distal end side of the second rotating shaft 40 toward the steering device 3. The shaft portion 403 of the second rotating shaft 40 is rotatably supported with respect to the first rotating shaft 38 via a bearing 405 provided in the recess 383 of the first rotating shaft 38.

  The coupling device 4 includes a cylindrical member 380 provided on the distal end side of the first rotary shaft 38 toward the reaction force applying device 2, a plurality of rollers 41 provided at intervals around the second rotary shaft 40, A plurality of spring members 42 provided between the plurality of rollers 41 and a cam member 401 provided on the outer peripheral side of the second rotating shaft 40 are configured.

  The cylindrical member 380 has a substantially hat-shaped cross section that opens toward the reaction force applying device 2 side. The hat-shaped portion of the cylindrical member 380 has an inner diameter that is larger than the outer diameter of the second rotating shaft 40.

  The plurality of rollers 41 are provided on the inner peripheral side of the cylindrical member 380 and in contact with the outer peripheral side of the cam member 401. In the example shown in FIG. 2 and FIG. 4, the plurality of rollers 41 is provided with three pairs (six) for convenience, including a pair of rollers (hereinafter sometimes referred to as “counter rollers”) 41. The plurality of spring members 42 are provided between the pair of rollers 41 so as to bias the pair of rollers 41 in the direction of separating the pair of rollers 41.

  The cam member 401 is formed in a substantially triangular prism shape with the apex portion chamfered so as to have three cam surfaces 407 orthogonal to the radial direction of the second rotation shaft 40. The counter roller 41 is provided on each of the three cam surfaces 407 of the cam member 401 so as to be in close contact with each other.

  In order to exhibit the function of switching between the first rotating shaft 38 and the second rotating shaft 40 to either the coupled state or the disconnected state, the connecting device 4 includes a switching device 44 (FIG. 3). (See FIG. 5).

  The switching device 44 reciprocates the switching claw portion 43 along the axial direction of the second rotating shaft 40 with respect to the cylindrical member 380, thereby combining the combination of the cam member 401 and the three pairs of rollers 41 with the cylindrical member 380. It has a function of mechanically controlling the wedge-shaped engagement relationship with the member 380.

  More specifically, the switching device 44 urges the outer peripheral portion of the second rotating shaft 40 in a direction to move the slider portion 440 away from the cam member 401 and a sleeve-like slider portion 440 that can reciprocate along the axial direction. And an annular slider ring 442 that is rotatably supported on the outer peripheral portion of the slider portion 440. However, the slider ring 442 is restricted from moving in the direction along the axial direction of the second rotating shaft 40.

  For example, in a metallic (not particularly limited) slider portion 440, three switching claw portions 43 are provided at equal intervals in the circumferential direction so as to extend integrally toward the steering device 3 side. . The three switching claw portions 43 are inserted inward of the cylindrical member 380 (see FIG. 2), the chamfered apex portions of the cam member 401 face each other, and the gaps between the three pairs of rollers 41 It is arranged so as to fill.

  The slider ring 442 is integrally provided with a pair of pin members 443 along the radial direction of the second rotary shaft 40 at positions facing each other across the second rotary shaft 40. A lever member 444 having an annular portion is provided on the outer peripheral side of the slider ring 442. The metal case 45 is provided with a fulcrum 446 of the lever member 444. On the other hand, a rod member 447A is linked to the force point 447 of the lever member 444. The rod member 447 </ b> A made of a magnetic material is provided so as to be insertable / removable with respect to the coil of the electromagnetic solenoid 448.

  In the annular portion of the lever member 444, a pair of long hole portions 445 extending in a direction orthogonal to the axial direction of the second rotation shaft 40 are respectively provided at positions facing each other across the second rotation shaft 40. It has been established. A pair of pin members 443 are provided to engage with the pair of long hole portions 445 of the lever member 444, respectively. Thereby, the rotation operation of the lever member 444 around the fulcrum 446 is performed in the axial direction of the second rotating shaft 40 in the slider ring 442 via the pair of pin members 443 engaged with the pair of long hole portions 445. It is configured to act as a movement.

  A plurality of splines 449 extending along the axial direction of the second rotating shaft 40 are formed on the inner peripheral portion of the slider portion 440. A plurality of splines 450 extending along the axial direction are also formed on the second rotating shaft 40 facing the inner peripheral portion of the slider portion 440 in the same manner as described above. As a result, the slider portion 440 is supported slidably along the axial direction while maintaining the engagement state between the splines 449 and 450 with respect to the second rotating shaft 40.

  The switching device 44 configured as described above operates as follows. That is, in a state where the coil of the electromagnetic solenoid 448 is magnetized by energization, the rod member 447A is positioned in the insertion direction with respect to the coil of the electromagnetic solenoid 448 as shown in FIG. At this time, the lever member 444 rotates counterclockwise as the force point 447 connected to the rod member 447A moves. Then, the rotation of the lever member 444 about the fulcrum 446 in the counterclockwise direction is performed by the slider portion toward the steering device 3 via the pair of pin members 443 engaged with the pair of long hole portions 445. 440 axial motion. As a result, the slider portion 440 moves toward the steered device 3 against the elastic force of the spring member 441. Along with the movement of the slider portion 440, the plurality of switching claw portions 43 are inserted inward of the cylindrical member 380 to fill the gaps between the three pairs of rollers 41 (see FIG. 2).

  When the plurality of switching claw portions 43 are inserted inward of the cylindrical member 380, each of the three pairs of rollers 41 is pushed in the circumferential direction by the wedge-shaped side portions of the three switching claw portions 43. To work. Thereby, each of the plurality of spring members 42 provided between the plurality of paired rollers 41 is in a compressed state. As a result, the outer peripheral edge portions of the plurality of counter rollers 41 and the inner peripheral edge portion of the cylindrical member 380 are separated, so that the first rotary shaft 38 and the second rotary shaft 40 are separated from each other. Maintained. In this separated state, the first rotating shaft 38 and the second rotating shaft 40 are freely rotatable relative to each other.

On the other hand, in a state where the coil of the electromagnetic solenoid 448 is demagnetized by stopping the energization, the rod member 447A is positioned in the removal direction with respect to the coil of the electromagnetic solenoid 448 by the spring member 441 as shown in FIG. At this time, the lever member 444 rotates clockwise as the force point 447 connected to the rod member 447A moves. Then, the clockwise rotation operation of the lever member 444 around the fulcrum 446 is performed by the slider portion 440 toward the steering device 3 via the pair of pin members 443 engaged with the pair of long hole portions 445. It is converted into the movement in the axial direction. As a result, the slider portion 440 receives the elastic force of the spring member 441 and moves to the reaction force applying device 2 side. As the slider portion 440 moves, the plurality of switching claw portions 43 come out of the inside of the cylindrical member 380, and the three pairs of rollers 41 are released from the pressing force by the three switching claw portions 43. (See FIG. 4).
The electromagnetic solenoid 448 is magnetized only when the drive signals of the electromagnetic solenoid 448 output from the first to third control devices 353, 363, and 393 are all on (energized). Otherwise, it operates to be demagnetized.

  When the plurality of switching claws 43 come out of the inside of the cylindrical member 380, the three pairs of rollers 41 are each subjected to the elastic force of the plurality of spring members 42 provided between the plurality of rollers 41, respectively. Thus, the distance between the pair of rollers 41 is greatly expanded to the set length of the spring member 42. Further, each of the three sets of counter rollers 41 is in close contact with three cam surfaces 407 of the cam member 401. As a result, the outer peripheral edge portions of the plurality of counter rollers 41 and the inner peripheral edge portion of the cylindrical member 380 are engaged in a wedge shape, whereby the space between the first rotating shaft 38 and the second rotating shaft 40 is established. , It is instantaneously switched from the disconnected state (see FIGS. 2 and 3) to the coupled state (see FIGS. 4 and 5).

  Actually, for example, as shown in Table 1, the control unit of the third control device 393 (and the first control device 353 and the second control device 363) has a location such as the steering torque sensor 16 or the like. When an abnormality diagnosis (multiple abnormality) is made in a plurality and EPS is selected as the steering function mode, control to cut off the power supply to the coupling device 4 is performed. As a result, the coil of the electromagnetic solenoid 448 is turned off. Thereafter, through the above procedure, the first rotary shaft 38 and the second rotary shaft 40 are switched from the disconnected state to the coupled state.

  Along with this switching, the fact that the member 444 has actually rotated clockwise is detected via a limit switch (see FIGS. 3 and 5) 451 corresponding to the “detector” of the present invention, and the communication medium 5 Is transmitted to the first to third control devices 353, 363, and 393. More specifically, the limit switch 451 detects the coupling state (coupled state or disconnected state) between the first rotating shaft 38 and the second rotating shaft 40 in the coupling device 4, and the detection result (coupled state signal). Is sent to the first to third control devices 353, 363, 393. Therefore, the abnormality diagnosis part of the 1st-3rd control apparatus 353,363,393 can grasp | ascertain the mechanical connection state in the coupling device 4 in real time by monitoring a connection state signal.

  At the start of the vehicle, the abnormality diagnosis unit of the first to third control devices 353, 363, 393, for example, the switching claw portion 43 does not enter the inside of the cylindrical member 380 due to the coupling state signal of the limit switch 451. An abnormality diagnosis related to such an event is performed. And the control part of the 1st-3rd control apparatus 353,363,393 performs reconstruction of a steering system as shown in Table 1 according to the said abnormality diagnosis result. Although details will be described later, for example, when an abnormality diagnosis result indicating that the switching claw portion 43 does not enter the inside of the cylindrical member 380 is given, the control units of the first to third control devices 353, 363, 393 are: Steering control is performed by setting the steering function mode to the EPS mode.

  By the way, at the start of activation of the vehicle steering apparatus 101 according to the embodiment of the present invention, the switching claw portion 43 of the coupling device 4 is in the coupled state. Specifically, for example, when the vehicle in which the switching claw portion 43 of the coupling device 4 is in the coupled state is parked, the steering handle 1 is suspended and an excessive load torque is applied to the coupling portion (cylindrical member) of the coupling device 4. 380, the outer peripheral edge of the plurality of counter rollers 41, and the cam surface 407 of the cam member 401, which are in contact with each other. Create a state. As a result, even when power is applied to the coupling device 4, the switching device 44 cannot insert the plurality of switching claw portions 43 inside the cylindrical member 380, and the coupling device 4 is disconnected from the coupled state. There is a possibility that it cannot be switched to the state.

  In order to eliminate such problems, the first to third control devices 353, 363, and 393 are configured so that the switching device 44 smoothly moves the plurality of switching claws 43 to the inside of the cylindrical member 380 regardless of the state of the coupling device 4. It corresponds so that it can be inserted. That is, the control units of the first to third control devices 353, 363, and 393 drive at least one of the first motor 332 and the second motor 342 and the third motor 181; The coupling portion is controlled to be released from the fixed state of the roller 41 and the cam surface 407. In this drive control, the coupling portion may be loosened by performing drive control that switches the rotation directions of the first to third motors 332, 342, and 181 in an oscillating manner with an appropriate period. Good.

★ [Basic Operation of Vehicle Steering Device 101 according to Embodiment of the Present Invention]
Next, the basic operation of the vehicle steering apparatus 101 according to the embodiment of the present invention will be described with reference to FIG. 6 and Table 1 as appropriate.
FIG. 6 is a flowchart for explaining the basic operation of the vehicle steering apparatus 101 according to the embodiment of the present invention.
Table 1 shows various sensors 6, 7, 8, 16, 17, 39, 332 A, 342 A, 184 A, first to third motors 332, 342 which are components of the vehicle steering apparatus 101 according to the present invention. , 181 and the first to third control devices 353, 363, and 393, a map in which types of appropriate steering function modes are described in association with each of single or combined abnormal portions. This map (the map described below is also the same) is stored in a storage unit (not shown) included in each of the first to third control devices 353, 363, and 393.

★

  First, when the ignition key switch of the vehicle is turned on, power is supplied to each of the first to third control devices 353, 363, and 393 from a vehicle-mounted battery (not shown) via a fuse. As a result, the first to third control devices 353, 363, and 393 first perform an initialization operation described later, and then sequentially execute the processing flow shown in FIG.

  In step S <b> 1, the first to third control devices 353, 363, 393 are connected to the vehicle speed sensor 6, the yaw rate sensor 7, the lateral acceleration sensor 8, the steering torque sensor 16, the steering angle sensor 17, the rack via the communication medium 5. Signals from various sensors including the position sensor 39 and the first to third current sensors 332A, 342A, 184A are input.

  In step S2, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 executes abnormality diagnosis processing. In the abnormality diagnosis process, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 includes various sensors 6, 7, 8, 16, 17, 39, 332A, 342A, 184A, first to third. The various functional units including the motors 332, 342, 181 and the first to third control devices 353, 363, 393 diagnose whether or not there is an abnormality.

  Here, the abnormality diagnosis relating to the various sensors 6, 7, 8, 16, 17, 39, 332A, 342A, 184A and the first to third motors 332, 342, 181 and the first to third Each diagnosis procedure will be specifically described separately in the abnormality diagnosis related to the control devices 353, 363, and 393.

  First, in the abnormality diagnosis related to the various sensors 6, 7, 8, 16, 17, 39, 332A, 342A, 184A, the abnormality diagnosis units of the first to third control devices 353, 363, 393 are multiplexed. A pair of detection signals from various sensors that have been made (duplicated) are compared with each other, and based on whether or not they match (including cases where they converge within a predetermined allowable range; the same applies hereinafter). Then, it is diagnosed whether various sensors are abnormal.

  The vehicle speed sensor 6 will be described as an example. The abnormality diagnosis unit of the first to third control devices 353, 363, 393 detects a pair of vehicle speeds from a pair of vehicle speed sensors 6 that are multiplexed (duplexed). The signals are compared with each other, and whether or not the vehicle speed sensor 6 is abnormal is diagnosed based on whether or not they match.

  The abnormality diagnosis unit of the first to third control devices 353, 363, and 393 is, for example, an engine rotation speed signal from a system other than the vehicle steering device 101 (for example, PGM-FI: ProGraMmed Fuel Injection). The vehicle speed sensor 6 may be diagnosed abnormally by taking in and comparing them via the communication medium 5.

  The first current sensor 332A will be described as an example. The abnormality diagnosis unit of the first to third control devices 353, 363, and 393 includes a pair of multiplexed first current sensors 332A. A pair of first current detection signals are compared with each other, and whether or not the first current sensor 332A is abnormal is diagnosed based on whether or not they match. In addition, the abnormality diagnosis unit of the first to third control devices 353, 363, and 393 includes a pair of second current detection signals from the second current sensor 342A and a pair of third current sensors 184A. An abnormality diagnosis similar to that described above is also performed for the third current detection signal.

  Further, the abnormality diagnosis unit of the first to third control devices 353, 363, and 393 makes a diagnosis that either one of the first current sensor 332A or the second current sensor 342A is abnormal. Also good. Explaining this, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 mutually compares the detection signal from the first current sensor 332A and the detection signal from the second current sensor 342A. However, a configuration may be adopted in which a diagnosis that either one of the first current sensor 332A or the second current sensor 342A is abnormal is made based on whether or not they match. If configured in this manner, an abnormality diagnosis can be performed without multiplexing the current sensors 332A and 342A, and the system configuration can be simplified.

  In addition, the abnormality diagnosis unit of the first to third motors 332, 342, and 181 is based on the abnormality diagnosis result based on the binary comparison between the first and second current sensors 332A and 342A, for example. The third motor 181 is diagnosed based on the result of comparing the drive command current value of the third motor 181 and the signal of the third current sensor 184A while making a diagnosis that the 332 or the second motor 342 is abnormal. A configuration may be adopted in which a diagnosis that there is an abnormality is made.

  Further, in the abnormality diagnosis related to the abnormality diagnosis unit of the first to third control devices 353, 363, 393, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 receives input and output respectively. By comparing the results of the common processing contents with each other in three values, a control device having a high probability of abnormality among the first to third control devices 353, 363, and 393 is specified. For example, in the case where the results for the common processing contents are the same for three parties (including the case of convergence within a predetermined allowable range; hereinafter the same), all the first to third controls are performed according to the principle of majority vote. The devices 353, 363 and 393 are diagnosed as correct.

  In the case where the result for the common processing content is the same for the two parties and the remaining one is different (including a case where the result deviates from a predetermined allowable range; hereinafter the same), the first to third The abnormality diagnosing unit of the control devices 353, 363, and 393, according to the majority rule as described above, diagnoses that the two are correct while diagnosing that the remaining one is incorrect.

  And when the result with respect to the said common process content differs between three persons, the abnormality diagnosis part of the 1st-3rd control apparatus 353,363,393 makes a diagnosis that all three persons are wrong.

  It should be noted that the abnormality diagnosis unit of the first to third control devices 353, 363, and 393 is connected to the connecting device 4 even though the disconnection command is output (the current steering function mode is the SBW control mode). If is in a combined state, it is diagnosed as abnormal. This is because the vehicle steering apparatus 101 according to the embodiment of the present invention has a self-steering state in which the actual turning angle overshoots the target turning angle, or the actual turning angle with respect to the target turning angle. This is based on avoiding an abnormal situation including a steering lock state that is difficult to follow. This will be described later in detail with reference to FIGS. 15A, 15B, and 16. FIG.

  The control units of the first to third control devices 353, 363, and 393 refer to the map (Table 1) based on the diagnosis result of whether or not an abnormality has occurred in all the sensors or function units in step S2. Then, the steering function mode corresponding to the diagnosis result is selected. In the map (Table 1), an appropriate steering function mode is described in association with the type of the abnormal part. For example, if no abnormality has occurred in all the sensors or function units (normal), the control units of the first to third control devices 353, 363, and 393 change the steering function mode to active variable gear ratio steering (Active Variable Gear). ratio Steering: hereinafter abbreviated as “active VGS”). On the other hand, when an abnormality has occurred in either the sensor or the functional unit, the first to third control devices 353, 363, and 393 refer to the map (Table 1) and appropriately determine the type of the abnormal part. Appropriate steering function mode is set appropriately.

  In step S3, if all the sensors or function units are normal in response to the diagnosis result of whether all the sensors or function units in step S2 are normal (Yes), the first to third The control devices 353, 363, and 393 advance the process flow to the next step S4.

  On the other hand, as a result of the determination in step S3, when it is determined that the steering function mode should not be set to the active VGS mode (No), that is, at least one of the sensors or the functional units is abnormal. When the determination is made, the first to third control devices 353, 363, and 393 cause the process flow to jump to step S6.

  In step S <b> 4, the control units of the first to third control devices 353, 363, and 393 perform control for bringing the coupling device 4 into a disconnected state by supplying power to the electromagnetic solenoid 448 of the coupling device 4.

  In step S5, the first to third control devices 353, 363, and 393 perform active VGS control for setting the steering function mode to the active VGS mode, and then return the processing flow to step S1. The active VGS control will be described later in detail.

  In step S6, if it is determined in step S3 that one or more of the sensors or functional units is abnormal, the first to third control devices 353, 363, 393 Control is performed to turn on an alarm lamp provided on an instrument panel (not shown) of the vehicle and to display an abnormality diagnosis location.

  In steps S7 to S22, the first to third control devices 353, 363, and 393 rebuild the steering system in accordance with the abnormality diagnosis result in step S2, as described below, and select an appropriate steering function mode. Is set to perform steering control.

  First, in step S7, the first to third control devices 353, 363, and 393 display the abnormality diagnosis result (indicating that the steering torque sensor 16 is abnormal) in step S2 and the steering function mode map in Table 1. Referring to this, it is determined whether or not the steering function mode should be set to the active VGS1 mode. As a result of the determination in step S7, if it is determined that the steering function mode should be set to the active VGS1 mode (Yes), the first to third control devices 353, 363, 393 The process proceeds to step S8.

  On the other hand, if it is determined in step S7 that the steering function mode should not be set to the active VGS1 mode (No), the first to third control devices 353, 363, 393 Let the flow jump to step S10.

  In step S <b> 8, the first to third control devices 353, 363, 393 perform control to place the coupling device 4 in a disconnected state by continuing power supply to the coupling device 4.

  In step S9, the first to third control devices 353, 363, and 393 perform active VGS1 control for setting the steering function mode to the active VGS1 mode, and then return the processing flow to step S1. The active VGS1 control will be described later in detail.

  In step S10, the first to third control devices 353, 363, and 393 activate the steering function mode with reference to the abnormality diagnosis result (indicating that the third current sensor 184A is abnormal) in step S2 as active VGS2. It is determined whether or not the mode should be set. As a result of the determination in step S10, if it is determined that the steering function mode should be set to the active VGS2 mode (Yes), the first to third control devices 353, 363, 393 To step S11.

  On the other hand, if it is determined in step S10 that the steering function mode should not be set to the active VGS2 mode (No), the first to third control devices 353, 363, 393 The flow is jumped to step S13.

  In step S <b> 11, the first to third control devices 353, 363, and 393 perform control for bringing the coupling device 4 into a disconnected state by continuing power supply to the coupling device 4.

  In step S12, the first to third control devices 353, 363, and 393 perform active VGS2 control for setting the steering function mode to the active VGS2 mode, and then return the processing flow to step S1. The active VGS2 control will be described later in detail.

  In step S13, the first to third control devices 353, 363, and 393 perform abnormality diagnosis in step S2 (that the third motor 181 or the third control device (third ECU) 393 is abnormal). With reference to the result, it is determined whether or not the steering function mode should be set to the active VGS3 mode. If it is determined in step S13 that the steering function mode should be set to the active VGS3 mode (Yes), the first to third control devices 353, 363, 393 To step S14.

  On the other hand, if it is determined in step S13 that the steering function mode should not be set to the active VGS3 mode (No), the first to third control devices 353, 363, 393 Let the flow jump to step S16.

  In step S <b> 14, the first to third control devices 353, 363, and 393 perform control to place the coupling device 4 in the disconnected state by continuing power supply to the coupling device 4.

  In step S15, the first to third control devices 353, 363, and 393 perform active VGS3 control for setting the steering function mode to the active VGS3 mode, and then return the processing flow to step S1. The active VGS3 control will be described later in detail.

  In step S16, the first to third control devices 353, 363, and 393 refer to the abnormality diagnosis result (indicating that the yaw rate sensor 7 or the lateral acceleration sensor 8 is abnormal) in step S2 to change the steering function mode. It is determined whether or not the VGS mode should be set. As a result of the determination in step S16, if it is determined that the steering function mode should be set to the VGS mode (Yes), the first to third control devices 353, 363, 393 Proceed to step S17.

  On the other hand, if it is determined in step S16 that the steering function mode should not be set to the VGS mode (No), the first to third control devices 353, 363, 393 To jump to step S19.

  In step S <b> 17, the first to third control devices 353, 363, 393 perform control to place the coupling device 4 in a disconnected state by continuing power supply to the coupling device 4.

  In step S18, the first to third control devices 353, 363, and 393 perform VGS control for setting the steering function mode to the VGS mode, and then return the processing flow to step S1. Details of the VGS control will be described later.

  In step S19, the first to third control devices 353, 363, and 393 control the switching of the coupling device 4 from the disconnected state to the coupled state by cutting off the power supply to the electromagnetic solenoid 448 of the coupling device 4. I do.

  In step S20, the first to third control devices 353, 363, and 393 control the steering angle sensor 17, the rack position sensor 39, the first current sensor 332A, the second current sensor 342A, the first Abnormality in which any of motor 332, first control device (first ECU) 353, second motor 342, second control device (second ECU) 363, or coupling device 4 is abnormal) Referring to the diagnosis result, it is determined whether or not the steering function mode should be set to the EPS mode. As a result of the determination in step S20, when it is determined that the steering function mode should be set to the EPS mode (Yes), the normal control device among the first to third control devices 353, 363, and 393 is: The process flow proceeds to the next step S21.

  On the other hand, if it is determined in step S20 that the steering function mode should not be set to the EPS mode (No), the first to third control devices 353, 363, 393 To jump to step S22.

  In step S21, a normal control device among the first to third control devices 353, 363, and 393 performs EPS control for setting the steering function mode to the electric power steering (EPS) mode, and then the flow of processing is performed. Return to step S1. Details of the EPS control will be described later.

  In step S22, the first to third control devices 353, 363, and 393 perform manual steering control for setting the steering function mode to the manual steering mode, and then return the processing flow to step S1. Details of manual steering control will be described later.

  Next, the active VGS control in step S5 will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of processing of a subroutine program related to active VGS.

  In step S50, the first to third control devices 353, 363, 393 use the signals of the steering angle sensor 17, the rack position sensor 39, and the vehicle speed sensor 6, and the steering angle based on the signals of the steering angle sensor 17. And the steering wheel turning angle based on the signal of the rack position sensor 39 is variably set according to the vehicle speed signal of the vehicle speed sensor 6, and thus the steering wheel turning angle that realizes the set gear ratio is set. The drive control of the first and second motors 332 and 342 is performed so that the current position of the rack shaft 32 follows. Such drive control of the first and second motors 332 and 342 is referred to as “VGS control”.

  More specifically, in the VGS control in step S50, the first to third control devices 353, 363, and 393 adjust the current vehicle speed by referring to a map in which appropriate gear ratios are set in advance according to changes in the vehicle speed. The corresponding gear ratio (VGS ratio) is read and set. Thereby, for example, the VGS ratio is set to a quick ratio that is 1 or less in the low vehicle speed range, that is, a gear ratio that increases the steering wheel turning angle with respect to the actual steering angle. Is set to a slow ratio with a value of 1 or more, that is, a gear ratio at which the steering wheel turning angle becomes smaller than the actual steering angle.

  The first to third controls are performed so that the current position of the rack shaft 32 follows the position of the rack shaft 32 corresponding to the steering wheel turning angle that realizes the gear ratio (VGS ratio) set in this way. The devices 353, 363, and 393 perform drive control of the first and second motors 332 and 342. The gear ratio (VGS ratio) is appropriately set in consideration that the yaw rate of the vehicle matches a predetermined steady value and that the lateral acceleration of the vehicle body does not exceed a predetermined limit value.

  During the drive control of the first and second motors 332 and 342, the first and second current values flowing through the first and second motors 332 and 342, respectively, are the first and second motors 332 and 342, When the first and second control devices 353 and 363, the first and second drive devices 35 and 36, etc. are normal, they are determined mainly based on the road surface load (friction coefficient).

  On the other hand, when the first and second motors 332 and 342, the first and second control devices 353 and 363, the first and second drive devices 35 and 36, etc. are abnormal, specifically, for example, When the one-phase winding of the first motor 332 is short-circuited, the current of the first motor 332 increases. Therefore, each of the first to third control devices 353, 363, and 393 monitors via the communication medium 5 whether or not such an event (current increase in the first motor 332) has occurred. The first and second current values monitored in this way are used when performing abnormality diagnosis of the first and second current sensors 332A and 342A, and when performing abnormality diagnosis of the first and second control devices 353 and 363. And so on.

  In step S <b> 51, the first to third control devices 353, 363, 393 use the signals of the steering angle sensor 17, the rack position sensor 39, the yaw rate sensor 7, and the lateral acceleration sensor 8 to output signals from the yaw rate sensor 7. Active gear ratio control for actively controlling the gear ratio (VGS ratio) independently of the steering angle based on the yaw rate of the vehicle based on the vehicle and the lateral acceleration of the vehicle body based on the signal of the lateral acceleration sensor 8 I do. Thereby, the behavior of the vehicle is stabilized.

  More specifically, in the active gear ratio control in step S51, the first to third control devices 353, 363, 393 are appropriate for the steering angle based on the signal of the steering angle sensor 17 and the change of the steering angle. By referring to a map in which the yaw rate and lateral acceleration are set in advance, the norm (target) yaw rate and the norm (target) lateral acceleration corresponding to the current steering angle are read and set, and the norm (target) value thus set In addition, the first and second motors 332 and 342 are feedback-controlled so that the yaw rate of the vehicle and the lateral acceleration of the vehicle body follow.

This contributes to stable driving of the vehicle by correcting disturbance factors such as differences in friction coefficient on the road surface (asphalt and snow-capped road) and unevenness (wadder) on the road surface, which were not considered in the VGS control in step S50. To do. In particular, even if the steering wheels 30a and 30b get stuck in the straight traveling of the vehicle or the vehicle body receives a crosswind, the driver only has to maintain the steering handle 1 in the straight traveling direction. The first to third control devices 353, 363, and 393 perform control so that the vehicle travels straight by automatically correcting the turning angles of the steering wheels 30a and 30b.
In short, the first to third control devices 353, 363, and 393 mechanically perform gear ratio control in the VGS control, but in the active gear ratio control, they automatically correct the disturbance factor finely to control the driver. Steering intention from the steering wheel 1 is set as a command (handle command), and the steering wheel turning angle is appropriately controlled independently of the steering angle by the steering handle 1.

In step S52, the first to third control devices 353, 363, and 393 determine the steering torque sensor 16, the steering angle sensor 17, the vehicle speed sensor 6, the yaw rate sensor 7, the signals from the lateral acceleration sensor 8, and the steering torque. Referring to a setting table (a table in which appropriate steering torque corresponding to each detection signal of steering torque sensor 16, steering angle sensor 17, vehicle speed sensor 6, yaw rate sensor 7, and lateral acceleration sensor 8 is set in advance) The target torque is increased so that the steering torque increases (heavy) as the steering angle sensor detection signal, yaw rate detection signal, and lateral acceleration detection signal increase, and the steering torque increases (heavy) as the vehicle speed increases. And the current steering torque based on the signal of the steering torque sensor 16 becomes the set target steering torque. To feedback control so as to follow. Such feedback control is referred to as “active reaction force control”.
Thereby, by giving an appropriate response when the steering handle 1 is operated, the self-aligning torque of the vehicle can be increased and the vehicle can be guided in a stable direction. As a result of the steering wheel 30a, 30b being returned (self-aligning torque) as if the driver merely touched the steering handle 1 and steered naturally in a stable direction, the steering handle 1 The operability can be improved.

More specifically, in the active reaction force control in step S52, the first to third control devices 353, 363, and 393 set an appropriate steering torque in advance according to the vehicle speed signal of the vehicle speed sensor 6 and the change in the vehicle speed. By referring to the map, the control of the steering handle 1 is set to be small in the low vehicle speed range, while the control of the steering handle 1 is set to be large in the high vehicle speed range.
Therefore, according to the steering angle of the steering handle 1, or according to the yaw rate or the lateral acceleration, and further considering the vehicle speed signal of the vehicle speed sensor 6, the response of the steering handle 1 is appropriately set. Therefore, the operability of the steering handle 1 can be improved.

  Further, when the vehicle has a tendency to spin, the detection signal of the yaw rate sensor 7 is increased and the steering reaction force (response) is controlled to be large (heavy), so that the self-aligning torque is increased and the spin is stopped. It is made easy to operate the steering handle 1 in the direction. Thus, by changing the response related to the operation direction of the steering handle 1, the driver can be prompted to operate the steering handle 1 appropriately. Further, in principle, since the steering handle 1 and the steering wheels 30a, 30b are not mechanically coupled, the road surface vibrations, kickback at steps, and the driving force difference between the steering wheels 30a, 30b Torque steer based on (front-wheel drive vehicle) can be eliminated.

  When the active reaction force control in step S52 ends, the first to third control devices 353, 363, and 393 return the process flow to step S1 in FIG. 6, and sequentially execute the following processes.

  Next, the active VGS1 control in step S9 will be described with reference to FIG. FIG. 8 is a flowchart showing the flow of processing of the subroutine program related to the active VGS1.

  The active VGS control shown in FIG. 7 and the active VGS1 control shown in FIG. 8 have common processing steps (S50 and S51). Therefore, description of these common processing steps (S50 and S51) will be omitted, and description will be made by paying attention to the difference between the two (step S53).

In Step S53, the first to third control devices 353, 363, and 393 that have made an abnormality diagnosis that the steering torque sensor 16 has an abnormality are the steering angle sensor 17, the vehicle speed sensor 6, the yaw rate sensor 7, and The steering torque setting table (the steering angle sensor 17, the vehicle speed sensor 6, the yaw rate sensor 7, and the appropriate steering torque corresponding to each detection signal of the lateral acceleration sensor 8 is set in advance. ), The steering torque on the steering handle 1 increases (heavy) according to the increase in the steering angle sensor detection signal, the yaw rate detection signal, and the lateral acceleration detection signal, and the vehicle speed increases. The target steering torque is increased according to the increase of the steering angle sensor detection signal, the yaw rate detection signal, and the lateral acceleration detection signal so that the steering torque is increased (heavy). Between the terminals of the third motor 181 using the differential signal of the steering angle sensor 17 as alternative information of the steering torque so that the current steering torque follows the set target steering torque. Control the voltage. Such control is called “reaction force control 1”.
Thereby, by giving an appropriate response when the steering handle 1 is operated, the self-aligning torque of the vehicle can be increased and the vehicle can be guided in a stable direction. As a result of the steering wheel 30a, 30b being returned (self-aligning torque) as if the driver had just put his hand on the steering handle 1, the steering wheel 30a, 30b was naturally steered in a stable direction. The lining torque can be increased to give the vehicle stability, and the operability of the steering handle 1 can be improved.

More specifically, in the reaction force control 1 in step S53, the first to third control devices 353, 363, and 393 set in advance an appropriate steering torque in accordance with the vehicle speed signal of the vehicle speed sensor 6 and the change in the vehicle speed. By referring to the map, the control of the steering handle 1 is set to be small in the low vehicle speed range, while the control of the steering handle 1 is set to be large in the high vehicle speed range.
Therefore, according to the steering angle of the steering handle 1, or according to the yaw rate or the lateral acceleration, and further considering the vehicle speed signal of the vehicle speed sensor 6, the response of the steering handle 1 is appropriately set. Therefore, the operability of the steering handle 1 can be improved.

  Further, when the vehicle has a tendency to spin, it is possible to prompt the driver to operate the steering handle 1 in a direction to stop spinning by changing the response related to the operation direction of the steering handle 1. Further, in principle, since the steering handle 1 and the steering wheels 30a, 30b are not mechanically coupled, the road surface vibrations, kickback at steps, and the driving force difference between the steering wheels 30a, 30b Torque steer based on (front-wheel drive vehicle) can be eliminated.

  However, in the reaction force control 1 in step S53, the first to third control devices 353, 363, and 393 display a warning for notifying the abnormality of the steering torque sensor 16 and increase the steering torque as compared with the normal state ( (Heavy) control. This notifies the driver in a timely manner that an abnormality has occurred in the steering system.

  When the reaction force control 1 in step S53 ends, the first to third control devices 353, 363, and 393 return the processing flow to step S1 in FIG. 6 and sequentially execute the following processing.

  Next, the active VGS2 control in step S12 will be described with reference to FIG. FIG. 9 is a flowchart showing the flow of processing of a subroutine program related to the active VGS2.

  The active VGS control shown in FIG. 7 and the active VGS2 control shown in FIG. 9 have common processing steps (S50 and S51). Therefore, description of these common processing steps (S50 and S51) will be omitted, and description will be made by paying attention to the difference between the two (step S54).

  In Step S54, the first to third control devices 353, 363, and 393 that have made an abnormality diagnosis that the abnormality has occurred in the third current sensor 184A are the steering torque sensor 16, the steering angle sensor 17, the vehicle speed sensor. 6, the signals of the yaw rate sensor 7 and the lateral acceleration sensor 8, and the steering torque setting table (the steering torque sensor 16, the steering angle sensor 17, the vehicle speed sensor 6, the yaw rate sensor 7, and the detection signals of the lateral acceleration sensor 8) The steering torque becomes larger (heavy) according to the increase in the steering angle sensor detection signal, the yaw rate detection signal, and the lateral acceleration detection signal. The target steering torque is set so that the steering torque increases (heavy) as the vehicle speed increases, and the current steering torque is set as described above. And so as to follow the target to become steering torque, by using the differential signal of the steering angle sensor 17, controls the inter-terminal voltage of the third motor 181. Such control is referred to as “reaction force control 2”.

  Thereby, by giving an appropriate response when the steering handle 1 is operated, the self-aligning torque of the vehicle can be increased and the vehicle can be guided in a stable direction. As a result of the steering wheel 30a, 30b being returned (self-aligning torque) as if the driver had just put his hand on the steering handle 1, the steering wheel 30a, 30b was naturally steered in a stable direction. The lining torque can be increased to give the vehicle stability, and the operability of the steering handle 1 can be improved.

  More specifically, in the reaction force control 2 in step S54, the first to third control devices 353, 363, and 393 set an appropriate steering torque in advance according to the vehicle speed signal of the vehicle speed sensor 6 and the change in the vehicle speed. By referring to the map, the control of the steering handle 1 is set to be small in the low vehicle speed range, while the control of the steering handle 1 is set to be large in the high vehicle speed range.

  Therefore, according to the steering angle of the steering handle 1, or according to the yaw rate or the lateral acceleration, and further considering the vehicle speed signal of the vehicle speed sensor 6, the response of the steering handle 1 is appropriately set. Therefore, the operability of the steering handle 1 can be improved.

  Further, when the vehicle has a tendency to spin, it is possible to prompt the driver to operate the steering handle 1 in a direction to stop spinning by changing the response related to the operation direction of the steering handle 1. Further, in principle, since the steering handle 1 and the steering wheels 30a, 30b are not mechanically coupled, the road surface vibrations, kickback at steps, and the driving force difference between the steering wheels 30a, 30b Torque steer based on (front-wheel drive vehicle) can be eliminated.

  However, in the reaction force control 2 in step S54, the first to third control devices 353, 363, and 393 perform warning display notifying the abnormality of the third current sensor 184A, and the steering torque as compared with the normal time. Make the control larger (heavy). This notifies the driver in a timely manner that an abnormality has occurred in the steering system.

  When the reaction force control 2 in step S54 ends, the first to third control devices 353, 363, and 393 return the processing flow to step S1 in FIG. 6 and sequentially execute the following processing.

  Next, the active VGS3 control in step S15 will be described with reference to FIG. FIG. 10 is a flowchart showing the flow of processing of a subroutine program related to the active VGS 3.

  Here, in the active VGS3 (step S15 in FIG. 6), the third motor 181 or the third control device (third ECU) 393 is abnormal, and the steering function mode is activated in step S13 in FIG. This process is executed when it is determined that the VGS3 mode should be set.

  If the third motor 181 or the third control device (third ECU) 393 is abnormal, the first or second control device 353, 363 may appropriately control the response of the steering handle 1. Have difficulty. This is because the third motor 181 and the third control device (third ECU) 393 mainly play a role of applying a reaction force against the steering torque.

  In consideration of the above circumstances, the first or second control device 353, 363 that has made an abnormality diagnosis that the abnormality has occurred in the third motor 181 or the third control device 393 in step S55 is shown in FIG. VGS control 1 is performed in accordance with the VGS control in step S50 shown in FIG. That is, in the VGS control 1 in step S55, the first or second control device 353, 363 uses the signals of the steering angle sensor 17, the rack position sensor 39, and the vehicle speed sensor 6 to calculate the gear ratio (VGS). The ratio is variably set according to the vehicle speed signal of the vehicle speed sensor 6 so as to become a slow ratio as compared with the VGS control example in step S50, and the steering wheel turning angle for realizing the gear ratio thus set is set to the rack. The drive control of the first and second motors 332 and 342 is performed so that the current position of the shaft 32 follows.

  In the VGS control 1 in step S55, the responsiveness of the steering wheel turning angle with respect to the operation amount of the steering handle 1 is reduced compared to the VGS control example in step S50. As a result, according to the VGS1 control in step S55, the driver is not caused to feel special discomfort even though the third motor 181 or the third control device (third ECU) 393 is abnormal. Thus, the behavior of the vehicle as a whole can be controlled slowly.

  In step S56, the first or second control device 353, 363 that has made an abnormality diagnosis that the third motor 181 or the third control device (third ECU) 393 is abnormal is shown in FIG. Active gear ratio control 1 according to the active gear ratio control in step S51 is performed. That is, in the active gear ratio control 1 in step S56, the first or second control device 353, 363 uses the signals of the steering angle sensor 17, the rack position sensor 39, the yaw rate sensor 7, and the lateral acceleration sensor 8. Based on the yaw rate of the vehicle based on the signal of the yaw rate sensor 7 and the lateral acceleration of the vehicle body based on the signal of the lateral acceleration sensor 8, compared with the example of the active gear ratio control in step S51 independently of the steering angle. The gear ratio (VGS ratio) is actively controlled so as to achieve a slow ratio. Thereby, the behavior of the vehicle is stabilized.

  More specifically, in the active gear ratio control 1 in step S56, the first or second control device 353, 363 determines the steering angle based on the signal from the steering angle sensor 17 and an appropriate yaw rate according to the change in the steering angle. The reference (target) yaw rate and the reference (target) lateral acceleration corresponding to the current steering angle are read and set by referring to a map in which the lateral acceleration is set in advance.

  In this setting, in the active gear ratio control 1 in step S56, each norm (target) value is set smaller (gentle) than in the example of the active gear ratio control in step S51. Then, the first and second motors 332 and 342 are feedback-controlled so that the yaw rate of the vehicle and the lateral acceleration of the vehicle body follow the norm (target) value thus set small (gently).

  Thereby, in the active gear ratio control 1 in step S56, the response of the steering wheel turning angle to the operation amount of the steering handle 1 is reduced as compared with the example of the active gear ratio control in step S51. As a result, according to the active gear ratio control 1 in step S56, the driver feels a particular sense of incongruity despite the abnormality of the third motor 181 or the third control device (third ECU) 393. Therefore, the behavior of the vehicle as a whole can be stabilized.

  FIG. 7 shows the first or second control device 353 or 363 that has made an abnormality diagnosis that the third motor 181 or the third control device (third ECU) 393 is abnormal in step S57. Reaction force control 3 according to the active reaction force control in step S52 is performed. That is, in the reaction force control 3 in step S57, the first or second control device 353, 363 performs control to open the respective contacts of the third parent relay 185 and the third child relay 186, The power supply to the third motor 181 and the third control device 393 is cut off.

  When the reaction force control 3 in step S57 ends, the first or second control device 353, 363 returns the process flow to step S1 in FIG. 6 and sequentially executes the following processes.

  Next, the VGS control in step S18 will be described with reference to FIG. FIG. 11 is a flowchart showing the flow of processing of a subroutine program related to VGS.

  The active VGS control shown in FIG. 7 and the VGS control shown in FIG. 11 have a common processing step (S50). Therefore, description of the common processing step (S50) will be omitted, and description will be made by paying attention to the processing of step S58 which only the VGS control shown in FIG.

  Here, in VGS (step S18 in FIG. 6), the yaw rate sensor 7 or the lateral acceleration sensor 8 is abnormal, and in step S18 in FIG. 6, it is determined that the steering function mode should be set to the VGS mode. This process is executed when

  In step S58, the first to third control devices 353, 363, and 393 that have made an abnormality diagnosis indicating that the yaw rate sensor 7 or the lateral acceleration sensor 8 is abnormal are reaction forces generally performed in electric power steering (EPS). Reaction force control 4 similar to the control is performed. That is, in the reaction force control 4 in step S58, the first to third control devices 353, 363, and 393 are adapted to the steering torque based on the signal from the steering torque sensor 16 and an appropriate target current corresponding to the change in the steering torque. , By referring to the map set in advance, the target current value to be given to each of the first to third control devices 353, 363, 393 is set according to the current steering torque, and the target current value thus set is set. On the other hand, drive control of the 1st-3rd motors 332,342,181 is performed so that the detected value of 1st-3rd current sensor 332A, 342A, 184A may track.

  This reduces the burden on the steering torque of the steering handle 1 by the driver. However, in the reaction force control 4 in step S58, the first to third control devices 353, 363, and 393 perform warning display notifying that the yaw rate sensor 7 or the lateral acceleration sensor 8 is abnormal, Control to increase (heavy) the steering torque is performed. This notifies the driver in a timely manner that an abnormality has occurred in the steering system.

  When the reaction force control 4 in step S58 ends, the first to third control devices 353, 363, and 393 return the processing flow to step S1 in FIG. 6 and sequentially execute the following processing.

  Next, the EPS control in step S21 will be described with reference to FIG. FIG. 12 is a flowchart showing the flow of processing of a subroutine program related to EPS.

  Here, the EPS (step S21 in FIG. 6) includes the steering angle sensor 17, the rack position sensor 39, the first current sensor 332A, the second current sensor 342A, the first motor 332, and the first control device (first control device). 1), the second motor 342, the second control device (second ECU) 363, or the clutch (not shown) is abnormal, and in step S21 of FIG. Is a process executed when it is determined that the setting of EPS mode should be set to EPS mode.

  In step S59, the steering angle sensor 17, the rack position sensor 39, the first current sensor 332A, the second current sensor 342A, the first motor 332, the first control device (first ECU) 353, the second The first to third control devices 353, 363, and 393 that perform abnormality diagnosis indicating that any of the motor 342, the second control device (second ECU) 363, or the clutch is abnormal are electric power steering systems. Reaction force control 5 similar to reaction force control generally performed in (EPS) is performed.

  That is, in the reaction force control 5 in step S59, the first to third control devices 353, 363, and 393 issue, for example, a signal from the limit switch 451 and a command signal for putting the coupling device 4 into a coupled state. Based on the situation, the abnormality diagnosis of the coupling device 4 (for example, the signal of the limit switch 451 is off (see FIG. 3) even though the command signal for putting the coupling device 4 into the coupled state is issued). ), The reaction force control 4 in step S58 is performed.

  In addition, an abnormality has occurred in any of the first motor 332, the first control device (first ECU) 353, the second motor 342, or the second control device (second ECU) 363. When the abnormality diagnosis is performed, the third control device 393 refers to the map in which the steering torque based on the signal of the steering torque sensor 16 and an appropriate target current corresponding to the change of the steering torque are set in advance. Then, the target current value of the third motor 181 corresponding to the current steering torque is set, and the third motor 184A follows the detected value of the third current sensor 184A with respect to the target current value thus set. The drive control of 181 is performed.

  This reduces the burden on the steering torque of the steering handle 1 by the driver. However, in the reaction force control 5 in step S59, the third control device 393 performs a warning display notifying the abnormal portion and performing control to increase (heavy) the steering torque as compared with the normal time. This notifies the driver in a timely manner that an abnormality has occurred in the steering system.

  When the reaction force control 5 in step S59 ends, the third control device 393 returns the process flow to step S1 in FIG. 6 and sequentially executes the following processes.

  Next, the manual steering control in step S22 will be described with reference to FIG. FIG. 13 is a flowchart showing the flow of processing of a subroutine program related to manual steering.

  Here, manual steering (step S22 in FIG. 6) is performed by either the third motor 3181 or the third control device (third ECU) 393 when the steering function mode is the EPS mode shown in FIG. This is a process that is executed when it is determined in step S22 in FIG. 6 that the steering function mode should be set to the manual steering mode.

  In step S59, when the steering function mode is the EPS mode, the first abnormality diagnosis is performed to indicate that an abnormality has occurred in either the third motor 3181 or the third control device (third ECU) 393. Alternatively, the second control devices 353 and 363 include the first parent relay 354 and the first child relay 355, the second parent relay 364 and the second child relay 365, and the third parent relay 185 and the third The third motor 181 and the third control device 393, the third motor 181 and the third control device 393, the third motor 181 and the third motor 181 are controlled by opening the respective contacts of the child relay 186. The power supply to the third control device 393 and the coupling device 4 is cut off, and all control functions of the first to third control devices 353, 363, 393 are turned off. As a result, the steering function mode is returned to the manual steering mode.

[Initialization Operation of Vehicle Steering Device 101 according to Embodiment of the Present Invention]
Next, the initialization operation of the vehicle steering apparatus 101 according to the embodiment of the present invention will be described with reference to FIGS. 14A and 14B as appropriate.
14A and 14B are flowcharts for explaining the initialization operation of the vehicle steering apparatus 101 according to the embodiment of the present invention.

  When the ignition key switch of the vehicle is turned on, power is supplied from the vehicle-mounted battery to each of the first to third control devices 353, 363, and 393 via a fuse. Accordingly, the first to third control devices 353, 363, and 393 sequentially execute the initialization process illustrated in FIGS. 14A and 14B. In this initialization process, the first to third control devices 353, 363, and 393 check the steering function mode to which the vehicle steering device 101 can be applied.

  In step S <b> 71, the first to third control devices 353, 363, 393 are connected to the vehicle speed sensor 6, the yaw rate sensor 7, the lateral acceleration sensor 8, the steering torque sensor 16, the steering angle sensor 17, the rack via the communication medium 5. Signals from various sensors including the position sensor 39 and the first to third current sensors 332A, 342A, 184A are input.

In step S72, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 performs an initial abnormality diagnosis process. In the initial abnormality diagnosis processing, the abnormality diagnosis unit of the first to third control devices 353, 363, 393 includes various sensors 6, 7, 8, 16, 17, 39, 332A, 342A, 184A, first to first. The three functional units including the three motors 332, 342, 181 and the first to third control devices 353, 363, 393 diagnose whether there is an abnormality.
Note that the processing content related to the initial abnormality diagnosis is the same as the processing content described in the abnormality diagnosis processing in step S2, and thus description thereof is omitted.

  In step S73, the control unit of the first to third control devices 353, 363, 393 refers to the initial abnormality diagnosis result in step S72, and an initial abnormality occurs in any of all sensors or functional units. Find out.

  In step S73, when a diagnosis that an initial abnormality has occurred in any of all sensors or functional units is made (Yes in step S73), the first to third control devices 353 are determined in step S74. , 363, 393 perform control to turn on an alarm lamp provided on the instrument panel of the vehicle and to display an abnormality diagnosis location.

In step S75, the control units of the first to third control devices 353, 363, and 393 refer to the map shown in Table 1 and select a steering function mode according to the diagnosis result.
In the map (Table 1), an appropriate steering function mode is described in association with the type of the initial abnormality location. For example, when no initial abnormality has occurred in all sensors or function units (normal), the control units of the first to third control devices 353, 363, and 393 perform steering by referring to the map (Table 1). While the active VGS is selected as the function mode, if an initial abnormality has occurred in any of the sensors or functional units, an appropriate steering function mode for the type of the abnormal part is appropriately selected.

In step S76, the control units of the first to third control devices 353, 363, and 393 select the steer-by-wire control mode (hereinafter, “steer-by-wire” may be abbreviated as “SBW”) as the steering function mode. Check whether it is applicable.
Examples of the SBW control mode include the above-described active VGS control, active VGS1 control, active VGS2 control, active VGS3 control, and VGS control. Further, the SBW control mode (with function restriction) means active VGS1 control, active VGS2 control, active VGS3 control, and VGS control.

  When it is determined in step S76 that the SBW control mode cannot be applied as the steering function mode (No in step S76), the control of the first to third control devices 353, 363, and 393 is performed in step S77. The unit selects the EPS mode as the assist control mode as the steering function mode and stands by (standby). Under circumstances where a relatively severe initial abnormality has occurred in any of the sensors or functional units, that is, for example, “◎” in the column of the steering function mode “EPS” or “manual steering” in Table 1. This is because it is appropriate to select the EPS mode (including the manual steering mode) as the assist control mode as the steering function mode under a situation where an abnormality has occurred at the part marked with.

  On the other hand, when it is determined in step S76 that the SBW control mode is applicable as the steering function mode (Yes in step S76), the first to third control devices 353, 363, and 393 are determined in step S78. The control unit outputs a disconnection command that puts the connecting device 4 into a disconnected state. In a situation where a relatively minor initial abnormality has occurred in any of the sensors or functional units, that is, for example, each of “active VGS” or “VGS” in the steering function mode “SBW” in Table 1 This is because it is appropriate to select the SBW control mode (with function limitation) as the steering function mode under a situation where an abnormality has occurred at a location marked with “◎” in the column.

  In step S <b> 79, the control units of the first to third control devices 353, 363, and 393 perform control for bringing the coupling device 4 into a disconnected state. Thereby, the coupling device 4 is in a disconnected state in principle (unless a special abnormality has occurred).

  In step S80, the control units of the first to third control devices 353, 363, and 393 determine whether or not the coupling device 4 is actually in the disconnected state based on the coupling state signal input from the limit switch 451. Check out.

  In step S80, when information indicating that the coupling device 4 is in the disconnected state is acquired by the information acquisition units of the first to third control devices 353, 363, and 393 (Yes in step S80), in step S81 The control units of the first to third control devices 353, 363, and 393 select the SBW control mode (with function limitation) as the steering function mode and stand by (standby).

  On the other hand, when information indicating that the connecting device 4 is not in the disconnected state (in the coupled state) is acquired by the information acquisition units of the first to third control devices 353, 363, and 393 in step S80 ( In step S80, in step S83, the control units of the first to third control devices 353, 363, and 393 select the EPS mode as the assist control mode as the steering function mode and stand by (standby). This is because the SBW control mode cannot be selected as the steering function mode when the coupling device 4 is not in the disconnected state (in the coupled state).

  In the standby (standby) state of steps S77, S81, and S83, the first to third control devices 353, 363, and 393 end a series of initialization processes.

  Now, in step S73, when a diagnosis is made that no initial abnormality has occurred in any of the sensors or functional units (No in step S73), in steps S84 shown in FIG. The control units of the third control devices 353, 363, and 393 output a disconnection command that causes the connecting device 4 to be disconnected. This is because it is appropriate to select the SBW control mode (no function restriction) as the steering function mode under a situation where no initial abnormality has occurred in any of the sensors or functional units.

  In step S85, the control units of the first to third control devices 353, 363, and 393 perform control so that the coupling device 4 is in the disconnected state. Thereby, the coupling device 4 is in a disconnected state in principle (unless a special abnormality has occurred).

  In step S86, the control units of the first to third control devices 353, 363, and 393 determine whether or not the coupling device 4 is actually in the disconnected state based on the coupling state signal input from the limit switch 451. Check out.

  In step S86, when the information acquisition part of the 1st-3rd control apparatus 353,363,393 acquires the information that the connection device 4 is in a separation state (Yes of step S86), in step S87 The control units of the first to third control devices 353, 363, and 393 select the SBW control mode (no function limitation) as the steering function mode and stand by (standby).

  On the other hand, when information indicating that the coupling device 4 is not in the disconnected state (in the coupled state) is acquired by the information acquisition units of the first to third control devices 353, 363, and 393 in step S86 ( In step S86, in step S88, the control units of the first to third control devices 353, 363, and 393 turn on an alarm lamp provided on the instrument panel of the vehicle and detect the abnormality diagnosis location (the coupling device 4). Is displayed.

  Next, in step S89, the control units of the first to third control devices 353, 363, and 393 select the EPS mode as the assist control mode as the steering function mode and stand by (standby).

  In the standby (standby) state of steps S87 and S89, the first to third control devices 353, 363, and 393 end a series of initialization processes.

[Connecting Device Abnormality Diagnosis Process Performed by Vehicle Steering Device 101 according to Embodiment of Present Invention]
Next, the connecting device abnormality diagnosis process performed by the vehicle steering device 101 according to the embodiment of the present invention will be described with reference to FIGS. 15A and 15B as appropriate. This connecting device abnormality diagnosis process corresponds to the abnormality diagnosis process according to step S2 of FIG.
FIG. 15A and FIG. 15B are flowcharts for explaining a coupling device abnormality diagnosis process performed by the vehicle steering device according to the embodiment of the present invention.

  In step S101 shown in FIG. 15A, the first to third control devices 353, 363, 393 are any one of the first to third control devices 353, 363, 393 (including a plurality, the same applies hereinafter). However, it is checked whether the disconnection command which makes the connection device 4 a disconnection state is output. Here, the case where any one of the first to third control devices 353, 363, and 393 outputs a disconnection command means that the current steering function mode is the SBW control mode.

  When it is determined in step S101 that the disconnect command has been output (Yes in step S101), in steps S102 to S103, the control units of the first to third control devices 353, 363, and 393 are Then, the coupling state signal input from the limit switch 451 is confirmed, and it is checked whether information indicating that the coupling device 4 is in the coupling state has been acquired.

  In Steps S101 to S103, when information indicating that the coupling device 4 is in the coupled state is acquired even though the disconnection command is output (the current steering function mode is the SBW control mode) (Step S101). In step S104, the control units of the first to third control devices 353, 363, and 393 perform control to switch the steering function mode from the SBW control mode to the EPS mode. As a result, the steering function mode is instantaneously switched from the SBW control mode to the EPS mode.

  Here, as in steps S <b> 101 to S <b> 103, in the case where the coupling device 4 is in the coupled state for some reason even though the disconnection command is output (the current steering function mode is the SBW control mode). The vehicle steering device according to the comparative example is in a self-steer state where the steering wheels 30a and 30b are steered beyond the steering intention of the driver, or the driver's steering intention is discounted to the steering device 3 side. There is concern that it will fall into an abnormal situation including the steering lock state that is reported.

  A mechanism in which the vehicle steering apparatus according to the comparative example falls into the abnormal state will be described using reference numerals of functional members included in the vehicle steering apparatus 101 according to the embodiment of the present invention. In the electric power steering (EPS) according to the existing technology, the first and second rack teeth 320, 321 provided on the rack shaft 32 connected to the steering wheels 30a, 30b, and the first and second rack teeth 320 are provided. , 321 through the rack and pinion mechanism including the first and second pinion gears 33, 34 that mesh with each other, the amount of rotation of the steering handle 1 in the direction along the rack shaft 32 (stroke amount). Is converted to The turning angle (steering angle) of the steering wheels 30a and 30b is determined by the stroke amount related to the rack shaft 32.

  At this time, the relationship between the stroke amount related to the rack shaft 32 and the rotation amount of the steering handle 1 is uniquely determined by the gear specifications (specifications) applied to the rack and pinion mechanism. Hereinafter, the relationship between the stroke amount related to the rack shaft 32 and the rotation amount of the steering handle 1 will be referred to as a specific stroke, and the set value will be referred to as Rg.

  By the way, in the SBW control mode, for example, when the vehicle speed is low, the specific stroke is set to be large so as to improve the handling performance. As described above, the specific stroke setting value Rg can be changed as appropriate according to the vehicle speed.

  Here, the SBW control mode cannot be applied as the steering function mode, and the failure specific stroke, which is a specific stroke when the coupling device 4 is brought into the coupled state, is a gear specification (linkage) applied to the rack and pinion mechanism. When the device 4 includes a differential mechanism, the fixed value is uniquely determined according to the gear specifications of the differential mechanism. Hereinafter, the fixed value of the failure specific ratio stroke is referred to as Rg_fail for convenience.

  Now, in the case where the set value Rg of the specific stroke exceeds the fixed value Rg_fail value of the specific stroke at the time of failure (for example, when the vehicle speed is low) under the SBW control mode, the connecting device 4 is switched from the disconnected state to the combined state. A case is assumed in which an abnormality to be switched has occurred but the switching has not been detected as an abnormality.

  In such a case, when the driver steers the steering handle 1 by a required amount of rotation, the rack shaft 32 is driven by the steered actuators (first and second motors 332 and 342) to set the specific stroke set value Rg. Is moved by the stroke amount according to. However, since the coupling device 4 is mistakenly connected, the stroke amount of the rack shaft 32 (the turning angle of the steering wheels 30a and 30b) is fixed to the failure specific stroke through the rack and pinion mechanism. As a result of acting on the steering handle 1 by an amount according to the value Rg_fail, the steering handle 1 rotates beyond the steering intention of the driver.

  In response, the vehicle steering apparatus according to the comparative example determines that the steering command has further increased. Then, according to the above procedure, the rack shaft 32 is moved by the stroke amount corresponding to the increase. Therefore, the vehicle steering apparatus according to the comparative example falls into a so-called self-steer state in which the steering wheels 30a and 30b are steered beyond the driver's steering intention.

  Further, in the case where the set value Rg of the specific stroke is less than the fixed value Rg_fail of the specific stroke at the time of failure (for example, when the vehicle speed is high) under the SBW control mode, the connecting device 4 is in the coupled state from the disconnected state. A case is assumed in which, even though an abnormality has occurred, the change was not detected as an abnormality.

  In such a case, when the driver steers the steering handle 1 by a required amount of rotation, the rack shaft 32 is driven by the steered actuators (first and second motors 332 and 342) to set the specific stroke set value Rg. Is moved by the stroke amount according to. However, since the coupling device 4 is mistakenly connected, the stroke amount of the rack shaft 32 (the turning angle of the steering wheels 30a and 30b) is fixed to the failure specific stroke through the rack and pinion mechanism. As a result of acting on the steering handle 1 by an amount according to the value Rg_fail, the steering handle 1 rotates below the driver's steering intention (the amount of excess rotation of the steering handle 1 is returned).

  Therefore, the vehicle steering device according to the comparative example falls into a so-called steering lock state in which the driver's steering intention is discounted and transmitted to the steering device 3 side.

  In addition, either in the EPS control mode or the manual steering mode, that is, when an abnormality occurs and the SBW control mode cannot be maintained and the connecting device 4 is switched from the disconnected state to the coupled state, If the connecting device 4 enters the disconnected state due to the occurrence of an abnormality at the point, a so-called steer-free state occurs.

  In summary, in the vehicle steering apparatus having the SBW control mode, the driving burden is reduced and the vehicle behavior is stabilized while avoiding the situation of falling into the self-steer state, the steering lock state, or the steer-free state. From the viewpoint of ensuring the safety, a rapid abnormality diagnosis and an appropriate response based on the abnormality diagnosis result are strongly demanded.

  Therefore, in the vehicle steering apparatus 101 according to the embodiment of the present invention, the coupling device 4 is in the coupled state even though the disconnection command is output (the current steering function mode is the SBW control mode). In such a case, the steering function mode is controlled to be switched from the SBW control mode to the EPS mode.

  In the vehicle steering apparatus 101 according to the embodiment of the present invention adopting the above-described configuration, the coupling device 4 is coupled even though the disconnection command is output (the current steering function mode is the SBW control mode). Considering that there is a risk of falling into a self-steering state, a steering lock state, or a steer-free state if such a situation is left as it is in the state, the steering function mode is switched from the SBW control mode to the EPS mode. Take control.

  According to the vehicle steering apparatus 101 according to the embodiment of the present invention, while avoiding the situation of falling into the self-steer state, the steering lock state, or the steer-free state, the driving burden is reduced and the vehicle behavior is stabilized. Can be ensured.

In step S105, the control units of the first to third control devices 353, 363, and 393 stop the disconnection command output from any of the first to third control devices 353, 363, and 393. Let
The stop command output stop process in step S105 is performed in the immediately preceding step S104 in view of the situation in which the disconnection operation of the coupling device 4 in accordance with the disconnect command is impossible, the steering function mode is changed from the SBW control mode to the EPS. This is done after switching to mode. This is because the vehicle steering apparatus 101 according to the embodiment of the present invention can reduce the period during which the coupling device 4 is in the coupled state as much as possible despite the disconnection command being issued. This is to avoid a situation in which the vehicle enters a self-steer state, a steering lock state, or a steer-free state.

  Thereafter, the first to third control devices 353, 363, and 393 cause the processing flow to jump to step S1 in FIG. Thereby, even if the situation where the control loop of FIG. 6 is repeated occurs, the steering function mode can be maintained in the EPS mode.

  The embodiment according to the present invention employs a configuration that quickly and preferentially switches the steering function mode to the EPS mode when it is detected that the coupling device 4 is in the coupled state under the SBW control mode. The behavior of the host vehicle can be stabilized.

  On the other hand, in steps S101 to S103, when a disconnection command is output (the current steering function mode is the SBW control mode) and information indicating that the coupling device 4 is in the disconnected state is acquired ( Step S103 No), that is, when under normal SBW control, in Step S106, the control units of the first to third control devices 353, 363, 393 are sensors necessary for maintaining the SBW function. Continuing to perform abnormality diagnosis processing such as

  In the abnormality diagnosis process according to step S106, the current steering function mode is any of the SBW control modes (including the above-described active VGS control, active VGS1 control, active VGS2 control, active VGS3 control, or VGS control). This is done to get a clue when judging the level.

  For example, the current steering function mode is one of the active VGS1 control, active VGS2 control, active VGS3 control, or VGS control (other than the active VGS control) in the SBW control mode. This means that there is a relatively minor abnormality commensurate with the current steering function mode. Therefore, by identifying the abnormal part in the abnormality diagnosis process according to step S106, a clue when determining the level to which the current steering function mode belongs can be obtained.

  If it is determined in step S107 that an abnormality has occurred in any of the sensors or functional units (Yes in step S107), in steps S108, the first to third control devices 353 are provided. The control units 363 and 393 perform control to store abnormal portions. The information relating to the abnormal location stored here is referred to when displaying the abnormal location or identifying the steering function mode in the control flow shown in FIG.

  On the other hand, if a diagnosis that no abnormality has occurred in any of the sensors or functional units is made in step S107 (No in step S107), the first to third control devices are used in step S109. The control units 353, 363, and 393 perform control to store that there is no abnormal part.

  When the storage process related to step S108 or S109 ends, the first to third control devices 353, 363, and 393 return the process flow to step S2 in the control flow shown in FIG. 6, and sequentially perform the following processes. Let it run.

  On the other hand, if it is determined in step S101 that the disconnect command has not been output (No in step S101), in steps S110 to S111, the first to third control devices 353, 363, 393 The control unit checks the coupling state signal input from the limit switch 451 and checks whether information indicating that the coupling device 4 is in the disconnected state has been acquired.

  In steps S101, S110 to S111, the connection command is output (the current steering function mode is either the EPS mode or the manual steering mode), but the coupling device 4 is in the disconnected state. When information is acquired (Yes in step S111), that is, when a flaw occurs between the command content (coupling command) and the state of the coupling device 4 (disengaged state), the first to third The control units of the control devices 353, 363, and 393 control the execution of the abnormality process.

  Here, in the abnormality process, the control units of the first to third control devices 353, 363, and 393 perform an abnormality display indicating that a flaw has occurred between the command content and the state of the coupling device 4, for example. At the same time, braking control is performed to decelerate (including stop) the vehicle speed of the host vehicle as necessary. This is because the behavior of the host vehicle may become unstable if the host vehicle continues to travel in a state where there is a flaw between the command content (joining command) and the state of the coupling device 4 (disengaged state). Because there is.

  Even if there is no flaw between the command content and the state of the coupling device 4, the control units of the first to third control devices 353, 363, and 393 depend on the failure state of the limit switch 451. May make a determination that the defects are occurring. In order to avoid such a complicated judgment, it is preferable to separately detect the failure of the limit switch 451.

  On the other hand, in steps S101 and S110 to S111, a combination command is output (the current steering function mode is either the EPS mode or the manual steering mode), and the coupling device 4 is in the combined state. When the information is acquired (No in step S111), that is, when the command content (coupling command) and the state of the coupling device 4 (coupling state) are normally matched, in step S112, the first to first 3 of the control devices 353, 363, and 393 continues to perform abnormality diagnosis processing such as sensors necessary for maintaining the EPS function and the manual steering function.

  The abnormality diagnosis process according to step S112 is performed in order to obtain a clue when determining whether the current steering function mode is the EPS mode or the manual steering mode.

  For example, if the current steering function mode is the EPS mode or the manual steering mode, any of all sensors or functional units has a relatively serious abnormality that matches the current steering function mode. It means that it has occurred. Therefore, by identifying the abnormal part in the abnormality diagnosis process according to step S112, a clue when determining the level to which the current steering function mode belongs can be obtained.

  In step S113, when a diagnosis is made that other abnormalities except for a relatively serious abnormal part grasped in advance are made (Yes in step S113), in steps S114, the first to third The control units of the control devices 353, 363, and 393 perform control to store the other abnormal points. The information relating to the other abnormal locations stored here is referred to when displaying the abnormal location or identifying the steering function mode in the control flow shown in FIG.

  On the other hand, when a diagnosis is made in step S113 that no other abnormality except for a relatively serious abnormality point that has been grasped in advance has occurred (No in step S113), in step S115, the first to first The control units of the third control devices 353, 363, and 393 perform control to store the fact that there is no other abnormal part except for the abnormal part that has been grasped in advance.

  When the storage process related to step S114 or S115 ends, the first to third control devices 353, 363, and 393 return the process flow to step S2 in the control flow shown in FIG. 6, and sequentially perform the following processes. Let it run.

[Operational Effects of the Vehicle Steering Device 101 according to the Embodiment of the Present Invention]
Next, functions and effects of the vehicle steering apparatus 101 according to the embodiment of the present invention will be described.
The vehicle steering apparatus 101 according to the first aspect includes a reaction force applying apparatus 2 that generates an operation input of a steering handle (steering member) 1 by a driver, and steering for steering the steering wheels 30a and 30b. A steering reaction force is applied to the reaction force applying device 2, a connecting device 4 that performs an operation of bringing the device 3, a reaction force applying device 2, and a steering device 3 into a mechanically coupled state or a separated state. The third motor (steering reaction force actuator), the first and second motors (steering actuators) 332 and 342 for applying steering torque to the steering device 3, and the coupling device 4 are in a coupled state or a disconnected state. An information acquisition unit for acquiring information on which one of them, a reaction force applying device 2, a steering device 3, a coupling device 4, a third motor (steering reaction force actuator), and first and second Operation control of motors (steering actuators) 332 and 342 And a control unit that performs.

  In particular, in the vehicle steering apparatus 101 based on the first aspect, the control units included in the first to third control apparatuses 353, 363, and 393 are provided with steering handles (when the connecting apparatus 4 is in the disconnected state). Steering member) The first and second motors (steering actuators) 332 and 342 are driven so as to have a turning angle corresponding to the operation state of the steering device 1, and steering according to the steering state of the steering device 3. The steering handle (steering member) by the driver when the steer-by-wire control mode for driving the third motor (steering reaction force actuator) 181 to apply the reaction force and the coupling device 4 are in the coupled state. Assist control mode for driving the third motor (steering reaction force actuator) 181 and at least one of the first and second motors (steering actuators) 332 and 342 to reduce the operation torque of 1 The information acquisition unit has acquired the information indicating that the coupling device 4 is in the coupled state, even though the steering function mode has at least the disconnection command to put the coupling device 4 in the disconnected state. In this case, a configuration is adopted in which the steering function mode is controlled to be switched from the steer-by-wire control mode to the assist control mode.

  In the vehicle steering device 101 based on the first aspect, the control unit included in the first to third control devices 353, 363, 393 outputs a disconnection command (the current steering function mode is the SBW control mode). However, when the coupling device 4 is in the coupled state, the steering is performed in view of the possibility of falling into a self-steer state, a steering lock state, or a steer-free state if the state is left as it is. Control to switch the function mode from the SBW control mode (steer-by-wire control mode) to the EPS mode (assist control mode) is performed.

  According to the vehicle steering device 101 based on the first aspect, it is possible to accurately prevent the steering handle from being pulled due to the coupling abnormality of the connecting device 4. Further, according to the vehicle steering apparatus 101 based on the first aspect, while avoiding the situation of falling into the self-steer state, the steering lock state, or the steer-free state, the driving burden is reduced and the vehicle behavior is reduced. Stability can be ensured.

  Further, in the vehicle steering device 101 based on the second aspect, the connecting device 4 detects an operation of bringing the reaction force applying device 2 and the steered device 3 into a mechanically coupled state or a separated state. The information acquisition unit included in the first to third control devices 353, 363, and 393 further includes a limit switch (detection unit) 451, and the connection device 4 is in a coupled state via the limit switch (detection unit) 451. It is characterized in that information on which of the separated states is acquired is obtained.

  In the vehicle steering control device according to Patent Document 1, the state determination as to whether the connecting device is in the coupled state or the disconnected state is made based on the actual steering angular velocity and the actual rotation calculated from the actual steering angle and the actual turning angle. Since the configuration is based on whether or not the deviation from the rudder angular velocity is less than or equal to a predetermined value, it is difficult to determine the state of the connecting device in a traveling scene where steering operation hardly occurs, for example, when traveling straight ahead. there were.

  In this regard, according to the vehicle steering device 101 based on the second aspect, the connecting device 4 makes the mechanically connected state or the disconnected state between the reaction force applying device 2 and the steered device 3. Since the limit switch (detection unit) 451 is detected to detect whether or not the steering handle (steering member) 1 is being operated by the driver, the connecting device 4 is connected or disconnected. Information on which state is in the state can be acquired.

  Moreover, according to the vehicle steering device 101 based on the second aspect, the connection device 4 is in the coupled state or the disconnected state via the limit switch (detection unit) 451 of the coupling device 4. Since the information can be acquired, it is possible to accurately grasp whether the coupling device 4 is in the coupled state or the disconnected state even at the start-up when the coupling device 4 is likely to have a coupling abnormality. it can. As a result, the phenomenon that the steering handle (steering member) 1 is taken due to the coupling abnormality of the coupling device can be prevented more appropriately.

[Connecting Device Abnormality Diagnosis Processing Performed by Vehicle Steering Device 101 according to Other Embodiment of the Present Invention]
Next, a connection device abnormality diagnosis process performed by the vehicle steering apparatus 101 according to another embodiment of the present invention will be described with reference to FIGS. 16 and 17 as appropriate.
FIG. 16 is a flowchart for explaining the coupling device abnormality diagnosis process performed by the vehicle steering apparatus 101 according to another embodiment of the present invention. FIG. 17 is a flowchart for explaining the basic operation of the vehicle steering apparatus 101 according to another embodiment shown in FIG. 16.

  The vehicle steering apparatus 101 according to the embodiment of the present invention and the vehicle steering apparatus 101 according to another embodiment of the present invention share the same physical components as shown in FIG. The logical components (software) of the three control devices 353, 363, and 393 are different.

  Then, about the connection apparatus abnormality diagnosis process (refer FIG. 16) which the steering apparatus 101 for vehicles which concerns on other embodiment of this invention performs the connection apparatus abnormality diagnosis process (refer FIG. 16) which concerns on embodiment of this invention ( In contrast with FIG. 15A), the description of the coincidence point between them (the step number is common) is omitted, and the difference between the two (steps S124 to S125 in FIG. 16: steps S104 to S105 in FIG. 15A). )).

  Further, the basic operation (see FIG. 17) of the vehicle steering apparatus 101 according to another embodiment of the present invention is compared with the basic operation (see FIG. 6) of the vehicle steering apparatus 101 according to the embodiment of the present invention. The description of the coincidence point between them (the step number is common) is omitted, and the difference between them (steps S131 to S133 shown in FIG. 17: between step S16 and step S19 shown in FIG. It will be explained by paying attention to newly inserted.)

  In the coupling device abnormality diagnosis process (see FIG. 15A) performed by the vehicle steering apparatus 101 according to the embodiment of the present invention, a disconnection command is output in steps S101 to S103 (the current steering function mode is the SBW control mode). However, if information indicating that the coupling device 4 is in the coupled state is acquired (Yes in step S103), the control of the first to third control devices 353, 363, and 393 is performed in step S104. The unit performs control to switch the steering function mode from the SBW control mode to the EPS mode.

  On the other hand, in the coupling device abnormality diagnosis process (see FIG. 16) performed by the vehicle steering apparatus 101 according to another embodiment of the present invention, a disconnection command is output in steps S101 to S103 (current steering) When information indicating that the coupling device 4 is in the coupled state is acquired despite the function mode being the SBW control mode (Yes in Step S103), the first to third control devices 353 are obtained in Step S124. , 363, 393 performs control to switch the steering function mode to the SBW control mode with a fixed gear ratio.

  Here, the gear ratio which is a fixed value is set in consideration of the fixed value Rg_fail of the ratio stroke at the time of failure. As described above, the fixed value Rg_fail of the stroke ratio stroke used here is the rack and pinion including the first and second rack teeth 320 and 321 and the first and second pinion gears 33 and 34. This value is uniquely determined according to the gear specifications (specifications) applied to the mechanism.

  Under the SBW control mode, when the coupling device 4 enters the coupled state against the driver's intention, the cause of the abnormal situation including the self-steering state or the steering lock state is the operation input amount of the steering handle 1 by the driver. This is because the relationship (specific stroke) with the steering amount (rack position change amount) of the steering wheels 30a, 30b is out of the appropriate range.

  Therefore, by setting the fixed gear ratio in consideration of the fixed ratio Rg_fail of the failure time ratio stroke, it is possible to avoid an abnormal situation including a self-steering state or a steering lock state. .

  In step S125, the control units of the first to third control devices 353, 363, and 393 continuously perform abnormality diagnosis processing such as sensors necessary for maintaining the SBW function. Thereafter, the first to third control devices 353, 363, and 393 cause the processing flow to jump to step S1 in FIG. Accordingly, even if the control loop of FIG. 6 is repeated, the steering function mode can be maintained in the gear ratio fixed SBW control mode.

  In order to introduce the fixed gear ratio SBW control mode of the vehicle steering apparatus 101 according to another embodiment of the present invention into the basic operation (see FIG. 6) of the vehicle steering apparatus 101 according to the embodiment of the present invention. In the basic operation (see FIG. 17) of the vehicle steering apparatus 101 according to another embodiment of the present invention, steps S131 to S133 shown in FIG. 17 are inserted between steps S16 and S19 shown in FIG. ing.

  In step S131, the first to third control devices 353, 363, and 393 determine whether or not the steering function mode should be set to the gear ratio fixed SBW control mode with reference to the abnormality diagnosis result in step S2. As a result of the determination in step S131, when it is determined that the steering function mode should be set to the gear ratio fixed SBW control mode (Yes), the first to third control devices 353, 363, 393 The flow is advanced to the next step S132.

  On the other hand, if it is determined in step S131 that the steering function mode should not be set to the gear ratio fixed SBW control mode (No), the first to third control devices 353, 363, and 393 are The process flow is jumped to step S19.

  In step S <b> 132, the first to third control devices 353, 363, 393 perform control to place the coupling device 4 in a disconnected state by continuing power supply to the coupling device 4.

  In step S133, the first to third control devices 353, 363, and 393 perform control to set the steering function mode to the gear ratio fixed SBW control mode, and then return the processing flow to step S1.

[Effects of the vehicle steering apparatus 101 according to another embodiment of the present invention]
Next, functions and effects of the vehicle steering apparatus 101 according to another embodiment of the present invention will be described.
In the vehicle steering apparatus 101 according to another embodiment of the present invention, the coupling device 4 is in the coupled state even though the disconnection command is output (the current steering function mode is the SBW control mode). In this case, the control unit of the first to third control devices 353, 363, and 393 adopts a configuration that performs control to switch the steering function mode to the SBW control mode with a fixed gear ratio.

  In the vehicle steering apparatus 101 according to another embodiment of the present invention, the fixed gear ratio is set in consideration of the fixed value Rg_fail of the failure ratio stroke. Therefore, in the vehicle steering apparatus 101 according to another embodiment of the present invention, the self-steering state and the steering which tend to occur when the coupling device 4 is in the coupled state despite the steering function mode being the SBW control mode. There will be no abnormal situations including locks.

  Therefore, according to the vehicle steering device 101 according to the other embodiment of the present invention, the connecting device 4 is connected even though the disconnection command is output (the current steering function mode is the SBW control mode). Even in the coupled state, it is possible to avoid an abnormal situation including a self-steer state or a steering lock state, and to realize smooth steering control as if EPS control is being performed. Can do.

[Contrast Effects of Vehicle Steering Device 101 According to Embodiment and Vehicle Steering Device According to Comparative Example]
Next, differences in the effects of the vehicle steering apparatus 101 according to the embodiment of the present invention and the vehicle steering apparatus according to the comparative example (Patent Document 1) will be described with reference to FIG.
FIG. 18 is an explanatory diagram that compares the difference in the effects of the vehicle steering device 101 according to the embodiment and the vehicle steering device according to the comparative example (Patent Document 1).

  In the vehicle steering device according to the comparative example (Patent Document 1), as described above, the state information indicating whether the coupling device is in the coupled state or the disconnected state is calculated from the actual steering angle and the actual turning angle. It is acquired based on whether or not the deviation between the actual steering angular velocity and the actual turning angular velocity is equal to or less than a predetermined value.

  Here, consider a case where the vehicle steering apparatus according to the comparative example (Patent Document 1) is operating normally in the SBW control mode. In such a case, the deviation between the rotational speed of the rotating shaft on the steering device side (actual steering angular velocity) and the rotational speed of the rotating shaft on the steering device side (actual turning angular velocity) never falls below a predetermined value. . Then, the steering angle ratio that is a fixed value is either Comparative Example 1 (quick that responds sensitively to the steering operation) or Comparative Example 2 (slow that responds slowly to the steering operation) in FIG. Here, it is assumed that the steering angle ratio according to Comparative Example 2 (slow that reacts slowly to the steering operation), which is advantageous for stabilizing the vehicle behavior, is employed.

  It is assumed that the steering function mode is instantaneously switched from the SBW control mode to the EPS mode or the manual steering mode under the above situation. Here, the steering angle ratio when the steering function mode is the EPS mode or the manual steering mode takes a value in the vicinity of the middle between the quick (Comparative Example 1) and the slow (Comparative Example 2). Then, for example, the steering function mode is switched from the SBW control mode to the EPS mode, and at the same time, the rudder angle ratio is changed from the slow value of the comparative example 2 to a value near the middle of the quick and slow. Become. Thus, the change in the steering angle ratio with the switching of the steering function mode is a major factor that gives the driver a sense of discomfort.

  In this respect, the vehicle steering apparatus 101 according to the embodiment of the present invention has an intermediate characteristic (near the middle of the quick and slow) with respect to the steering angle ratio (first embodiment) during normal operation in the SBW control mode. The steering angle ratio (Embodiment 2) that adopts the above can be set as the failed steering angle ratio when the coupling device is in the coupled state despite being in the SBW control mode.

  Thus, if the steering angle ratio having an intermediate characteristic is set, even if the steering function mode is instantaneously switched from the SBW control mode to the EPS mode or the manual steering mode, the steering function mode Since the change in the steering angle ratio that accompanies the switching can be suppressed to a low level, it is possible to suppress the driver from feeling uncomfortable.

[Other Embodiments]
The embodiments described above show examples of realization of the present invention. Therefore, the technical scope of the present invention should not be limitedly interpreted by these. This is because the present invention can be implemented in various forms without departing from the gist or main features thereof.

  For example, in the embodiment of the present invention, the first control device 353 mainly performs drive control of the first motor 332, the second control device 363 mainly performs drive control of the second motor 342, The configuration in which the control device 393 mainly performs drive control of the third motor 181 has been described as an example, but the present invention is not limited to this example.

  Instead of the above configuration, for example, when an abnormality occurs in the first control device 353, the second control device 363 performs drive control of the first motor 332 in addition to the second motor 342. You may employ | adopt the structure mainly performed. Further, a configuration is adopted in which the third control device 393 mainly performs drive control of the first motor 332 in addition to the third motor 181 when an abnormality occurs in the first control device 353. May be. Further, when an abnormality occurs in the first control device 353 and the second control device 363, the third control device 393 adds the first motor 332 and the second motor in addition to the third motor 181. A configuration that mainly performs the drive control of 342 may also be adopted.

In short, each of the first to third control devices 353, 363, and 393 may employ a configuration in which drive control of the first to third motors 332, 342, and 181 is performed in a mutually complementary manner. Good.
According to this configuration, even if one or two of the first to third control devices 353, 363, and 393 are abnormal, the first control device is used with the remaining control devices. Since the third motors 332, 342, and 181 can be driven and controlled, a sound steering function can be maintained as much as possible.

1 Steering handle (steering member)
DESCRIPTION OF SYMBOLS 2 Reaction force provision apparatus 3 Steering apparatus 4 Connection apparatus 30a, 30b Steering wheel 101 Steering device for vehicles 181 3rd motor (steering reaction force actuator)
332 1st motor (steering actuator)
342 Second motor (steering actuator)
353 1st control apparatus (ECU1; information acquisition part, control part)
363 2nd control apparatus (ECU2; information acquisition part, control part)
393 3rd control apparatus (ECU3; information acquisition part, control part)
451 Limit switch (detector)

Claims (2)

A reaction force applying device that generates an operation input of the steering member by the driver;
A steering device for steering the steering wheel;
A coupling device that performs an operation of bringing the reaction force application device and the steering device into a mechanically coupled state or a separated state; and
A steering reaction force actuator for applying a steering reaction force to the reaction force application device;
A steering actuator for applying a steering torque to the steering device;
An information acquisition unit for acquiring information on whether the coupling device is in a coupled state or a disconnected state;
The reaction force applying device, the turning device, the coupling device, the steering reaction force actuator, and a control unit that performs operation control of the turning actuator,
The controller is
When the connecting device is in the disconnected state, the steering actuator is driven so that the turning angle is in accordance with the operation state of the steering member, and the steering is in accordance with the steering state of the steering device. A steer-by-wire control mode for driving the steering reaction force actuator to apply a reaction force; and
When the coupling device is in a coupled state, an assist control mode for driving at least one of the steering reaction force actuator and the steering actuator so as to reduce an operation torque of the steering member by a driver is set to a steering function mode. At least as
The steer-by-wire control mode includes a gear ratio variable steer-by-wire control mode in which the specific stroke is variable according to changes in the vehicle speed, and a gear ratio fixed steer-by-wire control mode in which the specific stroke is fixed regardless of changes in the vehicle speed. Have
The steering function mode is set when information indicating that the coupling device is in the coupled state is acquired by the information acquisition unit even though a disconnection command for switching the coupling device is output. performs control for switching from the steer-by-wire control mode of the gear ratio varying the steer-by-wire control mode of the gear ratio fixed,
A vehicle steering control device. The coupling device further includes a detection unit that detects an operation of bringing the reaction force applying device and the steering device into a mechanically coupled state or a separated state,
The information acquisition unit acquires information on whether the coupling device is in a coupled state or a disconnected state via the detection unit.
The vehicle steering apparatus according to claim 1.

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