JP6131199B2 - Vehicle steering system - Google Patents

Description

  The present invention relates to a steer-by-wire vehicle steering apparatus.

  Some recent vehicles employ a steer-by-wire (SBW) steering system that transmits the driver's steering intentions to the steered wheels through electric wires. . In such an SBW system, the direction and amount of operation of the steering wheel by the driver are converted into electrical signals on the side of the steering unit, and are supplied to the steering unit including the steering motor. In response to this, the steered portion operates to steer the steered wheels according to the driver's steering intention by driving the steered motor according to the electric signal.

  In such an SBW system, an electric power steering (EPS) using a motor (steering reaction force motor or steered motor) that can be operated when an abnormality occurs, while controlling the operation in the SBW mode when it is normal. Backup for connecting or disconnecting the steering shaft on the steering unit side and the steered shaft on the steering unit side for the purpose of controlling the operation in the mode or manual steering (MS) mode. A clutch (hereinafter referred to as “connecting portion”) is provided.

  For example, in Patent Document 1, a steering handle operated by a driver and a steering handle are mechanically separated from each other, and a steering mechanism that steers left and right front wheels according to an operation state of the steering handle, a steering handle and a steering mechanism, When the fastening condition of the connecting portion is established in a state where the connecting portion is mechanically fastened, and when the connecting portion is disconnected, a fastening command means for outputting a fastening command to the connecting portion, and a fastening command is output to the connecting portion. After that, there is disclosed a vehicle steering control device that includes an engagement determination unit that determines that the connecting portion is in an engagement state when an increase in torque of the steering wheel is detected.

  According to the vehicle steering control device according to Patent Document 1, it is possible to accurately determine whether or not the connecting portion is actually fastened regardless of the change in the fastening time related to the connecting portion. Even immediately after being fastened to, the steering mode can be smoothly changed from the SBW mode to the EPS mode without a sense of incongruity.

JP 2007-230472 A

  By the way, in the vehicle steering control device according to Patent Document 1, reference is made to a configuration for smoothly shifting the steering mode from the SBW mode to the EPS mode immediately after the coupling portion is actually fastened. There is no description or suggestion of a configuration for providing a comfortable driving environment in which noise and vibration are suppressed after the steering mode transitions from the SBW mode to the EPS mode. In this regard, there is still room for improvement in the technology related to the vehicle steering control device according to Patent Document 1.

  The present invention has been made in view of the above circumstances, and noise and vibration are suppressed even after the steering mode transitions from the steer-by-wire (SBW) mode to the assist (EPS) mode. The purpose is to maintain a comfortable driving environment.

  In order to achieve the above object, the invention according to (1) includes a steering unit in which an operation input of a steering member by a vehicle driver is generated, a steering unit for steering steered wheels, and the steering unit. And a connecting portion that performs a switching operation for bringing the steering portion into a mechanically coupled state or a separated state, a steering reaction force actuator that applies a steering reaction force to the steering portion, and a steering portion. A steering actuator that applies steering torque, a steering torque detector that detects steering torque that the driver is sensitive to, a steering angle information acquisition unit that acquires information related to the steering angle of the steering member, and at least the steering A steering unit, the steering unit, the coupling unit, the steering reaction force actuator, an abnormality diagnosis unit that performs abnormality diagnosis of the steering actuator, the steering unit, the steering unit, the coupling unit, and the steering reaction force Actuator and steering And a control unit for controlling the operation of the actuator, the.

  The control unit drives the steering actuator so that the steering angle is in accordance with the operation state of the steering member when the connecting unit is in a disconnected state, and the steering unit steers the steering unit. Steer-by-wire mode for driving the steering reaction force actuator so as to apply a steering reaction force according to the state, and the operation torque of the steering member by the driver when the connecting portion is in the coupled state When the steering mode is the steer-by-wire mode, the steering mode has at least an assist mode for driving at least one of the steering reaction force actuator or the steering actuator so as to reduce As a result of the abnormality diagnosis by the abnormality diagnosis unit, an abnormality diagnosis relating to a portion that does not interfere with the driving of the steering reaction force actuator and the steering actuator was made. The steering mode is controlled from the steer-by-wire mode to the assist mode, and the information related to the steering angle acquired by the steering angle information acquisition unit is obtained after the connection unit is switched to the coupled state. The most important feature is that the operation of the steering actuator is controlled so as to output a steering force based thereon.

  As a result of the abnormality diagnosis by the abnormality diagnosis unit, in order to assist the driver's steering force when an abnormality diagnosis relating to a portion that does not interfere with the driving of the steering reaction force actuator and the steering actuator (for example, the steering torque detection unit) is made The type of actuator (steering reaction force actuator or steering actuator) and how to determine the driving force are problematic.

Therefore, in the invention according to (1), when an abnormality diagnosis relating to a portion that does not interfere with driving of the steering reaction force actuator and the steering actuator is made, the steering mode is switched from the steer-by-wire mode to the assist mode. In this case, the control unit controls the operation of the steering actuator so that the steering force based on the information related to the steering angle acquired by the steering angle information acquisition unit is output after the coupling unit is switched to the coupled state.
Generally, the steering actuator is provided in an engine room that is isolated from the passenger compartment of the vehicle. On the other hand, the steering reaction force actuator is provided near the passenger compartment of the vehicle. Therefore, the steering actuator can be driven in a state in which the quietness with respect to the passenger compartment of the vehicle is maintained as compared with the steering reaction force actuator.

  According to the invention according to (1), after the connecting portion is switched to the coupled state, the operation control of the steered actuator is performed so as to output the steering force based on the information related to the steering angle acquired by the steering angle information acquiring portion. For this reason, even when an abnormality diagnosis related to a portion that does not hinder the driving of the steering reaction force actuator and the steering actuator is made, compared with the case of obtaining the steering force by operating the steering reaction force actuator, Silence can be maintained for the guest room. As a result, a comfortable driving environment in which noise and vibration are suppressed can be maintained even after the steering mode has transitioned from the steer-by-wire (SBW) mode to the assist (EPS) mode.

  The invention according to (2) is the vehicle steering device according to (1), further including a turning angle information acquisition unit that acquires information related to a turning angle of the turning wheel, and the control When the steering mode is the steer-by-wire mode, when an abnormality diagnosis related to the steering torque detection unit is made as a result of the abnormality diagnosis by the abnormality diagnosis unit, the steer-by- Control for switching the steering mode from the wire mode to the assist mode, and information related to the steering angle acquired by the steering angle information acquisition unit after the connecting unit is switched to the coupled state, and the turning angle information acquisition unit The operation control of the steered actuator is performed so as to output a steering force based on the information related to the steered angle acquired in step (1).

  In the invention according to (1), as described above, the operation control of the steering actuator is performed so as to output the steering force based on the information related to the steering angle acquired by the steering angle information acquisition unit. In this case, the problem is how to optimize the driving force of the steering actuator for assisting the driver's steering force.

  In this regard, in the invention according to (2), the control unit switches the information acquired by the steering angle information acquisition unit and the turning angle information acquisition unit after the connection unit is switched to the coupled state. The configuration is adopted in which the operation of the steering actuator is controlled so as to output the steering force based on the information related to the steering angle.

  According to the invention according to (2), the control unit, after the connection unit is switched to the coupled state, information related to the steering angle acquired by the steering angle information acquisition unit and the steering acquired by the steering angle information acquisition unit. Comfortable driving environment in which noise and vibration are suppressed and the magnitude of the driving force of the steering actuator is optimized in order to control the operation of the steering actuator to output the steering force based on information related to the corner Can be held.

  According to the present invention, it is possible to maintain a comfortable driving environment in which noise and vibration are suppressed even after the steering mode is changed from the steer-by-wire (SBW) mode to the assist (EPS) mode. it can.

1 is a schematic configuration diagram of a vehicle steering apparatus according to an embodiment of the present invention. It is process drawing with which it uses for operation | movement description of the steering apparatus for vehicles which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a vehicle steering apparatus according to an embodiment of the present invention.
The vehicle steering device 11 is a steer-by-wire (SBW) type steering device. The vehicle steering device 11 is configured to generate a steering force by driving the steering motor 29 described later, for example, when the steering reaction motor 16 described later fails, the driver's steering device 11 is driven by the steering motor 29. In the case of an electric power steering (EPS) mode for generating an assisting force related to manual steering, and when the steering reaction force motor 16 and the steering motor 29 fail, for example, the driver performs manual steering. A manual steering mode is provided as a steering mode.

  In order to realize the steering mode, the vehicle steering device 11 includes a steering wheel 13, a steering reaction force generating device 15, a steering device 17, and a clutch mechanism 19, as shown in FIG. The vehicle steering device 11 is mounted on the vehicle V. The vehicle V includes a pair of steered wheels 21a and 21b.

  The steering wheel 13 is a member that is operated according to the driving intention of the driver. The steering wheel 13 corresponds to the “steering member” of the present invention. A steering shaft 23 is provided on the steering wheel 13. The steering shaft 23 is configured to rotate around the axis in accordance with the operation of the steering wheel 13 by the driver.

The steering reaction force generation device 15 has a function of generating a reaction force (response) related to steering at the driver's hand holding the steering wheel 13 when the vehicle steering device 11 is operating in the SBW mode. The steering reaction force generator 15 has a steering reaction force motor 16. A steering shaft 23 is connected to the steering reaction force motor 16. The steering reaction force motor 16 generates a steering torque for rotating the steering shaft 23 around the axis. As a result, when the vehicle steering device 11 is operating in the SBW mode, a reaction force (responsiveness) related to steering is transmitted to the driver's hand holding the steering wheel 13.
The steering reaction force generator 15 and the steering shaft 23 correspond to the “steering portion” of the present invention.

The steered device 17 has a function of converting the rotational motion of the steered shaft 25 into the linear motion of the rack shaft 27 via a rack and pinion mechanism (not shown). The steering device 17 has a steering motor 29. A steered shaft 25 and a rack shaft 27 are connected to the steered motor 29. The turning motor 29 generates a turning torque for causing the rack shaft 27 to linearly move along the axial direction. A pair of steered wheels 21a and 21b are connected to the rack shaft 27 via tie rods (not shown). The pair of steered wheels 21 a and 21 b are steered by a linear motion of the rack shaft 27.
The steered device 17 having the steered shaft 25, the rack shaft 27, and the steered motor 29 corresponds to the “steered portion” of the present invention.

The clutch mechanism 19 has a function of connecting or disconnecting the steering shaft 23 and the steered shaft 25. In order to realize such a function, the clutch mechanism 19 includes a planetary gear mechanism 31. The planetary gear mechanism 31 includes an internal gear 31a, a planetary gear 31b, a sun gear 31c, and a planet carrier 31d.
The clutch mechanism 19 corresponds to the “connecting portion” of the present invention.

  The clutch mechanism 19 includes a locking gear 33 and a locking device 35. The lock device 35 includes a lock pin 39 that engages with a tooth groove of the lock gear 33, and an electromagnetic solenoid 37 that drives the lock pin 39.

  The internal gear 31 a is fixed to a side end portion of the steering device 17 in the steering shaft 23 and is configured to rotate integrally with the steering shaft 23. The sun gear 31c is configured to freely rotate around a rotation axis coaxial with the steered shaft 25. A plurality of planetary gears 31b are provided so as to engage with each of the sun gear 31c and the internal gear 31a. Each of the plurality of planetary gears 31b is rotatably supported with respect to a planet carrier 31d that rotates integrally with the steered shaft 25.

The locking gear 33 is an external gear. The locking gear 33 is configured to rotate integrally with the sun gear 31c. The lock pin 39 is urged in a direction close to the locking gear 33 by an urging means (not shown). When the lock pin 39 is engaged with the tooth groove of the locking gear 33, the rotational movement of the locking gear 33 is restricted.
The electromagnetic solenoid 37 operates to release the engagement between the lock pin 39 and the locking gear 33 by displacing the lock pin 39 by supplying the exciting current.
The locking device 35 is configured to operate according to a control signal sent from the control device 40. The control device 40 operates to release the engagement of the lock pin 39 with the locking gear 33 by supplying an excitation current to the electromagnetic solenoid 37.

Next, the operation of the clutch mechanism 19 will be described. When the lock pin 39 engages with the tooth groove of the locking gear 33, the rotational movement of the sun gear 31c that rotates together with the locking gear 33 is restricted.
When the driver operates the steering wheel 13 in a state where the rotational movement of the sun gear 31 c is restricted, the internal gear 31 a rotates with the rotation of the steering shaft 23. At this time, since the rotational movement of the sun gear 31c is restricted, the planetary gear 31b revolves around the sun gear 31c while rotating. Due to the revolution of the planetary gear 31b, the planetary carrier 31d that pivotally supports the planetary gear 31b and the turning shaft 25 that rotates integrally with the planetary carrier 31d rotate.

  In short, in a state where the lock pin 39 is engaged with the tooth groove of the locking gear 33, the clutch mechanism 19 is in a coupled state in which the steering shaft 23 and the steered shaft 25 are coupled. At this time, the rotational force of the steering shaft 23 is transmitted to the steered shaft 25.

On the other hand, when the engagement of the lock pin 39 with the tooth groove of the locking gear 33 is released, the sun gear 31c that rotates integrally with the locking gear 33 becomes rotatable.
When the driver operates the steering wheel 13 with the sun gear 31c being rotatable, the internal gear 31a is rotated with the rotation of the steering shaft 23. At this time, the planetary gear 31b tries to revolve around the sun gear 31c while rotating. However, the steered wheels 21 a and 21 b are connected to the planetary carrier 31 d through the steered shaft 25 and the rack shaft 27. For this reason, the resistance force against the rotation of the planet carrier 31d is much larger than the resistance force against the rotation of the sun gear 31c in a rotatable state. Therefore, when the planetary gear 31b rotates, the sun gear 31c rotates (rotates), and the planet carrier 31d does not rotate. That is, the steered shaft 25 does not rotate.

  In short, in a state where the lock pin 39 is disengaged from the tooth groove of the lock gear 33, the clutch mechanism 19 is separated from the steering shaft 23 and the steered shaft 25. At this time, the rotational force of the steering shaft 23 is not transmitted to the steered shaft 25.

Next, an input / output system for the control device 40 will be described.
The control device 40 includes, as input systems, a steering angle sensor 41, a steering torque sensor 43, a steering reaction force motor resolver 45, a steered motor resolver 47, a rack stroke sensor 49, a vehicle speed sensor 51, a yaw rate sensor 53, and a lateral acceleration. A sensor 55 is connected.

  The steering angle sensor 41 and the steering torque sensor 43 are provided on the steering shaft 23. The steering angle sensor 41 detects the steering angle of the steering wheel 13 by the driver, and gives the detected steering angle information to the control device 40. Further, the steering torque sensor 43 detects the steering torque of the steering wheel 13 by the driver, and gives the detected steering torque information to the control device 40. The steering torque sensor 43 corresponds to the “steering torque detector” of the present invention.

  The steering reaction force motor resolver 45 is provided in the steering reaction force motor 16. The steering reaction force motor resolver 45 detects the rotational operation amount (steering angle) of the steering reaction force motor 16 and supplies the detected steering angle information to the control device 40.

  The steered motor resolver 47 is provided in the steered motor 29. The steered motor resolver 47 detects the rotational operation amount (steered angle) of the steered motor 29 and provides the detected steered angle information to the control device 40.

  The rack stroke sensor 49 is provided on the rack shaft 27. The rack stroke sensor 49 detects the linear movement amount (steering angle) of the rack shaft 27 and provides the detected turning angle information to the control device 40. In place of or in addition to the rack stroke sensor 49, a rotation amount (steering angle) of a pinion shaft (not shown) engaged with the rack shaft 27 is detected, and the detected turning angle information is given to the control device 40. May be adopted.

  The vehicle speed sensor 51 detects the speed (vehicle speed) of the vehicle V and gives the detected vehicle speed information to the control device 40. The yaw rate sensor 53 detects the yaw rate of the vehicle V and provides the detected yaw rate information to the control device 40. The lateral acceleration sensor 55 detects the lateral acceleration (lateral G) of the vehicle V and provides the detected lateral G information (actually measured lateral G value) to the control device 40.

  On the other hand, the control device 40 is connected to the steering reaction force motor 16, the steering motor 29, and the electromagnetic solenoid 37 as an output system.

  The control device 40 sets the operation mode of the vehicle steering device 11 to the SBW mode, the EPS mode, the operation mode of the vehicle steering device 11 based on the detection signal input via the input system and the abnormality diagnosis result related to various components of the vehicle steering device 11. Alternatively, a function for determining one of the manual steering modes and a function for generating control signals for controlling the driving of the steering reaction force motor 16, the steering motor 29, and the electromagnetic solenoid 37 in accordance with the determined operation mode. In addition, based on the generated control signal, the steering reaction force motor 16, the steering motor 29, and the electromagnetic solenoid 37 are controlled to be driven.

  Specifically, the control device 40 includes a steering angle information acquisition unit 61, a turning angle information acquisition unit 63, an abnormality diagnosis unit 65, and a control unit 67.

  The steering angle information acquisition unit 61 has a function of acquiring information related to the steering angle from the steering angle sensor 41 or the steering reaction force motor resolver 45.

  The turning angle information acquisition unit 63 has a function of acquiring information related to the turning angle from the turning motor resolver 47 or the rack stroke sensor 49.

  The abnormality diagnosis unit 65 has a function of performing abnormality diagnosis of various sensors including the steering reaction force generator 15, the steering device 17, the clutch mechanism 19, and the steering angle sensor 41 and the steering torque sensor 43.

  When the vehicle steering device 11 is operating in the SBW mode, the control unit 67 performs drive control of the steering reaction force motor 16 so that the driver's hand holding the steering wheel 13 can be appropriately steered. It operates to convey such reaction force (response).

  In addition, the control unit 67 controls the turning of the steered wheels 21a and 21b according to the driver's driving intention by performing drive control of the steered motor 29 when the vehicle steering apparatus 11 is operating in the SBW mode. Operate to steer.

  Further, the control unit 67 performs drive control to switch the supply or stop of the excitation current to the electromagnetic solenoid 37 according to the operation mode of the vehicle steering device 11, thereby changing the state of the clutch mechanism 19 to the connected state or the disconnected state. Operates to switch to one of the states.

  Specifically, when the steering mode is the SBW mode, the control unit 67, as a result of the abnormality diagnosis by the abnormality diagnosis unit 65, does not interfere with the driving of the steering reaction force motor 16 and the steering motor 29 (for example, steering When abnormality diagnosis relating to the torque sensor 43) is made, it has a function of performing control to switch the steering mode from the SBW mode to the EPS mode.

  In particular, when the diagnosis of the steering torque sensor 43 being abnormal is made as a result of the abnormality diagnosis by the abnormality diagnosis unit 65, the control unit 67 includes information on the steering angle acquired by the steering angle information acquisition unit 61, And it has a function which performs operation control of the steering motor 29 so that the steering force based on the information concerning the turning angle acquired by turning angle information acquisition part 63 may be outputted.

  Next, the operation of the vehicle steering device 11 when an abnormality occurs in the steering torque sensor 43 when the steering mode of the vehicle steering device 11 is the SBW mode will be described with reference to FIG. FIG. 2 is a process diagram for explaining the operation of the vehicle steering apparatus according to the embodiment of the present invention.

  In step S1, the vehicle steering device 11 is operating with the steering mode set to the normal SBW mode.

  If any abnormality occurs in the steering torque sensor 43 in step S <b> 2, the abnormality diagnosis unit 65 makes a diagnosis that the steering torque sensor 43 is abnormal and transmits the abnormality diagnosis result to the control unit 67.

In step S3, the control unit 67 that has received the abnormality diagnosis result indicating that the steering torque sensor 43, which is a portion that does not hinder the driving of the steering reaction force motor 16 and the steering motor 29, is abnormal, changes the steering mode from the SBW mode. Control to switch to the EPS mode is performed.
Here, in the general EPS mode, the operation control of the steered motor 29 is usually performed so that a steering force based on the steering torque detected by the steering torque sensor 43 is output.
However, when the steering torque sensor 43 falls into an abnormal state, the type of actuator (steering reaction force motor 16 or the steering motor 29) for assisting the driver's steering force without using information related to the steering torque, And how to determine the driving force is a problem.

  Therefore, in the vehicle steering apparatus 11 according to the embodiment of the present invention, after the clutch mechanism (connecting unit) 19 is switched to the coupled state, the control unit 67 acquires information related to the steering angle acquired by the steering angle information acquiring unit 61. And the operation control of the steered motor 29 is performed so as to output the steering force based on the information related to the steered angle acquired by the steered angle information acquiring unit 63.

More specifically, the control unit 67 first performs a steering angle estimation process and a turning angle estimation process.
In the steering angle estimation process, the steering angle information acquisition unit 61 integrates the rotation angle θr1 (electrical angle of the rotor) sent from the steering reaction force motor resolver 45 to calculate the motor electrical angle θre1.

Next, as shown in the following equation (1), the steering angle information acquisition unit 61 multiplies the calculated motor electrical angle θre1 by the number of pole pairs of the steering reaction force motor resolver 45, thereby rotating the rotor (steering shaft 23). Is converted to a motor mechanical angle θrm, which is the rotation angle of the motor.
Motor mechanical angle θrm1 = motor electrical angle θre1 × resolver pole pair number (1)

Next, the steering angle information acquisition unit 61 refers to the speed reduction ratio of the speed reduction mechanism interposed between the steering shaft 23 and the steering reaction force motor 16 as shown in the following equation (2). The converted motor mechanical angle θrm is converted into the rotation angle (estimated steering angle) θsc1 of the steering shaft 23.
Estimated steering angle θsc1 = motor mechanical angle θrm1 × speed reduction ratio of speed reduction mechanism (2)
Further, the steering angle information acquisition unit 61 calculates the estimated steering angular velocity θsc1 ′ [deg / s] by differentiating the estimated steering angle θsc1 with respect to time.

  Even if the steering torque sensor 43 falls into an abnormal state by the above procedure, the steering angle information acquisition unit 61 determines the estimated steering angle θsc1 based on the rotation angle θr1 sent from the steering reaction force motor resolver 45. [Deg] and the estimated steering angular velocity θsc1 ′ [deg / s] can be obtained.

Using the same procedure as described above, the turning angle information acquisition unit 63, based on the rotation angle θr2 sent from the turning motor resolver 47, the estimated turning angle θsc2 [deg] and the estimated steering angular velocity θsc2 ′ [ deg / s].
For details on the procedure for obtaining the estimated steering angle θsc1 and the estimated turning angle θsc2, the procedure described in WO2011105154 A1 may be referred to as appropriate.

  The control unit 67 refers to a map (a characteristic of the drive current related to the steered motor 29 with respect to the estimated steering angle θsc1 and the estimated steered angle θsc2) stored in advance in a storage unit (not shown), and calculates the estimated A drive current related to the steered motor 29 corresponding to the steering angle θsc1 and the estimated steered angle θsc2 is calculated, and drive control of the steered motor 29 is performed based on the calculated drive current related to the steered motor 29.

  However, the control unit 67 refers to a map (a characteristic of the drive current related to the steering motor 29 with respect to the estimated steering angle θsc1) stored in advance in the storage unit, and the steering corresponding to the calculated estimated steering angle θsc1. A configuration may be adopted in which the drive current related to the motor 29 is calculated, and the drive control of the steered motor 29 is performed based on the calculated drive current related to the steered motor 29.

  The control unit 67 corresponds to the calculated estimated turning angle θsc2 with reference to a map (a characteristic of the drive current relating to the turning motor 29 with respect to the estimated turning angle θsc2) stored in advance in the storage unit. A configuration may be adopted in which the drive current related to the steered motor 29 is calculated, and the drive control of the steered motor 29 is performed based on the calculated drive current related to the steered motor 29.

[Operational Effects of the Vehicle Steering Device 11 According to the Embodiment of the Present Invention]
In the vehicle steering device 11 based on the first aspect (corresponding to claim 1), the steering units 15 and 23 in which the operation input of the steering wheel (steering member) 13 by the driver of the vehicle V is generated, and the steered wheels 21a, The steering part 17, 25, 27 for turning 21b, and the switching operation which makes between the steering parts 15, 23 and the steering parts 17, 25, 27 a mechanical coupling state or a separated state is performed. A clutch mechanism (connecting portion) 19, a steering reaction force motor (steering reaction force actuator) 16 that applies a steering reaction force to the steering portions 15 and 23, and a turning force that applies a turning torque to the steering portions 17, 25, and 27. Steering motor (steering actuator) 29, steering torque sensor (steering torque detector) 43 for detecting steering torque to which the driver is sensitive, and steering for acquiring information related to the steering angle of the steering wheel (steering member) 13 The information acquisition unit 61, at least the steering units 15, 23, the steering units 17, 25, 27, the clutch mechanism (connection unit) 19, the steering reaction force motor (steering reaction force actuator) 16, and the steering motor (turning) (Steering actuator) 29 for diagnosing an abnormality, steering units 15 and 23, steering units 17, 25 and 27, clutch mechanism 19, steering reaction force motor 16, and steering motor 29. And a control unit 67 for performing.

  The control unit 67 drives the steering motor 29 so that the steering angle is in accordance with the operation state of the steering wheel (steering member) 13 when the clutch mechanism (connecting unit) 19 is in the disconnected state. Steer-by-wire mode that drives the steering reaction force motor 16 so as to apply a steering reaction force according to the turning state of the turning portions 17, 25, and 27, and the clutch mechanism (connecting portion) 19 are coupled. The steering mode includes at least an assist mode for driving one of the steering reaction force motor 16 and the steered motor 29 so as to reduce the operation torque of the steering wheel (steering member) 13 by the driver, When the steering mode is the steer-by-wire mode, as a result of the abnormality diagnosis by the abnormality diagnosis unit 65, the portion that does not hinder the driving of the steering reaction force motor 16 and the turning motor 29 When the abnormality diagnosis is performed, the steering mode is controlled from the steer-by-wire mode to the assist mode, and after the clutch mechanism (connecting portion) 19 is switched to the coupled state, the steering angle information acquiring portion 61 The operation control of the turning motor (steering actuator) 29 is performed so as to output the steering force based on the information relating to the steering angle acquired in step S2.

  As a result of the abnormality diagnosis by the abnormality diagnosis unit 65, when an abnormality diagnosis relating to a portion that does not interfere with the driving of the steering reaction force motor 16 and the steering motor 29 (for example, the steering torque sensor 43) is made, information regarding the steering torque is displayed. Without being used, the type of actuator for assisting the steering force of the driver (the steering reaction force motor 16 or the steering motor 29) and how to determine the driving force become a problem.

Therefore, in the vehicle steering apparatus 11 based on the first aspect, the assist from the steer-by-wire mode is performed when an abnormality diagnosis relating to a portion that does not hinder the driving of the steering reaction force motor 16 and the steering motor 29 is made. When switching the steering mode to the mode, the control unit 67 outputs the steering force based on the information related to the steering angle acquired by the steering angle information acquisition unit 61 after the clutch mechanism (connection unit) 19 is switched to the coupled state. Thus, the operation control of the steering motor (steering actuator) 29 is performed.
In general, the steering motor (steering actuator) 29 is provided in an engine room isolated from the cabin of the vehicle V. On the other hand, the steering reaction force motor (steering reaction force actuator) 16 is provided in the vicinity of the passenger compartment of the vehicle. Therefore, the steered motor 29 can be driven in a state where the quietness of the vehicle V with respect to the passenger cabin is maintained as compared with the steering reaction force motor 16. In addition, since the output of the steering motor 29 is larger than that of the steering reaction force motor 16 in general, it is advantageous from the viewpoint of sufficiently securing the assisting force related to the driver's steering.

  According to the vehicle steering device 11 based on the first aspect, even when an abnormality diagnosis is made on a portion that does not hinder the driving of the steering reaction force motor 16 and the steering motor 29, the steering reaction force motor 16 is provided. Compared to the case where the steering force is obtained by operating the, the quietness of the cabin of the vehicle V can be maintained. As a result, a comfortable driving environment in which noise and vibration are suppressed can be maintained even after the steering mode has transitioned from the steer-by-wire (SBW) mode to the assist (EPS) mode.

  The vehicle steering apparatus 11 based on the second aspect (corresponding to claim 2) further includes a turning angle information acquisition unit 63 that acquires information related to the turning angles of the turning wheels 21a and 21b. When the steering mode is the steer-by-wire mode, when the abnormality diagnosis related to the steering torque sensor (steering torque detection unit) 43 is made as a result of the abnormality diagnosis by the abnormality diagnosis unit 65, the unit 67 Control for switching the steering mode from the by-wire mode to the assist (EPS) mode, and information related to the steering angle acquired by the steering angle information acquiring unit 61 after the clutch mechanism (connecting unit) 19 is switched to the coupled state; And the structure which performs operation control of the steering motor (steering actuator) 29 so that the steering force based on the information concerning the steering angle acquired by the steering angle information acquisition unit 63 is output is adopted. Good.

  In the vehicle steering device 11 based on the first aspect, as described above, the steering motor (steering actuator) 29 is configured to output the steering force based on the information related to the steering angle acquired by the steering angle information acquisition unit 61. Control the operation. In this case, the problem is how to optimize the driving force (output) of the steering actuator for assisting the driver's steering force.

  In this regard, in the vehicle steering apparatus 11 based on the second aspect, the control unit 67 is configured to obtain information on the steering angle acquired by the steering angle information acquisition unit 61 after the clutch mechanism (connection unit) 19 is switched to the coupled state. In addition, a configuration is adopted in which operation control of the steered motor (steering actuator) 29 is performed so as to output a steering force based on information related to the steered angle acquired by the steered angle information acquiring unit 63.

  According to the invention according to (2), a comfortable driving environment in which noise and vibration are suppressed and the magnitude of the driving force (output) of the steering actuator for assisting the driver's steering force is optimized. Can be held.

[Other Embodiments]
The plurality of 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 description according to the embodiment of the present invention, an example in which the clutch mechanism 19 having the planetary gear mechanism 31 is provided has been described, but the present invention is not limited to this example. The clutch mechanism 19 may have any configuration as long as the steering shaft 23 and the steered shaft 25 can be connected or disconnected.

  In the description of the embodiment of the present invention, the steering reaction force motor 16 is provided with a steering reaction force motor resolver 45 as a steering angle detection means, and the steering motor 29 is provided with a steering motor resolver as a turning angle detection means. Although the configuration in which 47 is provided has been described as an example, the present invention is not limited to this example. A configuration may be adopted in which the steering reaction force motor 16 is provided with a rotary encoder as steering angle detection means, and the steering motor 29 is provided with a rotary encoder as steering angle detection means.

  Further, in the description according to the embodiment of the present invention, the control unit 67 refers to a map (a characteristic of the drive current related to the steered motor 29 with respect to the estimated steering angle θsc1 and the estimated steered angle θsc2) stored in the storage unit in advance. The driving current related to the steered motor 29 corresponding to the calculated estimated steering angle θsc1 and estimated steered angle θsc2 has been described with reference to the example of calculating the drive current by the table lookup method. It is not limited. The control unit 67 uses the calculated estimated steering angle θsc1 and estimated turning angle θsc2 and a predetermined calculation formula, and the turning motor 29 corresponding to the estimated steering angle θsc1 and the estimated turning angle θsc2. The drive current according to may be calculated.

  The calculation formula may be used instead of the table lookup method in the case of calculating the drive current related to the steered motor 29 corresponding to the calculated estimated steering angle θsc1, or the calculated estimated steered The same applies to the case where the drive current related to the turning motor 29 corresponding to the angle θsc2 is calculated.

11 Steering device for vehicle 13 Steering wheel (steering member)
15 Steering reaction force generator (steering part)
16 Steering reaction force motor (steering reaction force actuator)
17 Steering device (steering part)
21a, 21b Steering wheel 23 Steering shaft (steering member)
25 Steering shaft (steering part)
27 Rack shaft (steering part)
29 Steering motor (steering actuator)
61 Steering angle information acquisition unit 63 Steering angle information acquisition unit 65 Abnormality diagnosis unit 67 Control unit V Vehicle

Claims (2)

A steering unit in which an operation input of the steering member by the driver of the vehicle occurs;
A steering unit for steering the steered wheels;
A connecting portion that performs a switching operation to bring the steering portion and the steered portion into a mechanically coupled state or a separated state; and
A steering reaction force actuator for applying a steering reaction force to the steering unit;
A steering actuator that is provided in an engine room separated from a cabin of the vehicle and applies a steering torque to the steering unit;
A steering torque detector for detecting steering torque to which the driver is sensitive;
A steering is provided in a steering reaction force motor of the steering reaction force actuator and is connected to a steering reaction force motor resolver for detecting the rotational operation amount of the steering reaction force motor, and obtains information related to the steering angle of the steering member. A corner information acquisition unit;
At least, the steering unit, the steering unit, the coupling unit, the steering reaction force actuator, and an abnormality diagnosis unit that performs an abnormality diagnosis of the steering actuator;
The steering unit, the steered unit, the connecting unit, the steering reaction force actuator, and a control unit that controls the operation of the steered actuator,
The controller is
When the connecting portion is in a disconnected state, the steering actuator is driven so as to have a turning angle according to the operation state of the steering member, and steering according to the steering state of the steering portion. In the steer-by-wire mode in which the steering reaction force actuator is driven to apply a reaction force, and when the connecting portion is in a coupled state, the operation torque of the steering member by the driver is reduced. Having at least an assist mode for driving at least one of the steering reaction force actuator or the steering actuator as a steering mode;
When the steering mode is the steer-by-wire mode, when an abnormality diagnosis related to the steering torque detection unit is made as a result of the abnormality diagnosis by the abnormality diagnosis unit , the steering-by-wire mode Control to switch the steering mode to the assist mode,
After the connecting portion is switched to the coupled state, the steering actuator is controlled to output a steering force based on information related to the steering angle acquired by the steering angle information acquiring portion.
A vehicle steering apparatus characterized by the above. The vehicle steering apparatus according to claim 1,
A steering angle information acquisition unit for acquiring information related to the steering angle of the steered wheel;
The controller is
When the steering mode is the steer-by-wire mode, when an abnormality diagnosis related to the steering torque detection unit is made as a result of the abnormality diagnosis by the abnormality diagnosis unit, the steering-by-wire mode Control to switch the steering mode to the assist mode,
After the connection unit is switched to the coupled state, the steering force based on the information related to the steering angle acquired by the steering angle information acquisition unit and the information related to the steering angle acquired by the steering angle information acquisition unit is output. To control the operation of the steering actuator,
A vehicle steering apparatus characterized by the above.

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