JP2015089774A - Vehicular steering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the setting of an appropriate a steering angle ratio by virtue of a simple configuration.SOLUTION: A steering apparatus includes: a steering wheel 13 being operated when steering-wheels 21a, 21b of a vehicle V are steered; a steering angle sensor 41 for detecting a steering-operation angle on the steering wheel 13; steering-mechanisms 17, 25, 27, 29 for steering the steering-wheels 21a, 21b in the state of being mechanically disengaged from the steering wheel 13; a steering angle sensor 49 for detecting a steering angle on the steering-wheels 21a, 21b; a predicted-lateral G value calculation part 61 for obtaining behavior information related to a behavior of the vehicle V; and a steering angle ratio setup part 63 for setting a steering angle ratio that is a ratio of the steering angle to the steering-operation angle. The steering angle ratio setup part 63 sets a steering angle ratio on the basis of a predicted-lateral G value calculated by the predicted-lateral G value calculation part 61.

Description

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

  Recently, a steering device of a type called Steer By Wire has been developed. Patent Document 1 discloses a steering device for a vehicle of a steer-by-wire (SBW) system.

  An SBW-type vehicle steering apparatus according to Patent Literature 1 includes a setting unit that sets a steering angle ratio that is a ratio of a change in the turning angle of a steered wheel to a change in the steering angle of a steering wheel, and the set steering angle ratio. A steering angle controller that drives the steering actuator so as to obtain a target steering angle calculated based on the steering angle. The setting unit sets a steering angle ratio characteristic in which the steering angle ratio decreases as the steering angle absolute value increases, while having a region where the steering angle ratio is constant.

  According to the vehicle steering control device of the SBW system according to Patent Literature 1, it is possible to appropriately perform the trajectory correction steering of the vehicle while reducing the uncomfortable feeling related to the steering given to the driver.

JP 2004-306717 A

  However, in the SBW-type vehicle steering control device according to Patent Document 1, in order to set an appropriate steering angle ratio according to changes in the vehicle speed and the steering angle, a map of the steering angle ratio corresponding to the change in the steering angle is used. It was necessary to prepare for each different vehicle speed. Therefore, there is a problem that the configuration for setting an appropriate steering angle ratio is complicated.

  The present invention has been made to solve the above-described problems, and an object thereof is to realize an appropriate steering angle ratio setting with a simple configuration.

  In order to solve the above-mentioned problem, the invention according to (1) includes a steering member that is operated when turning a steered wheel of a vehicle, a steering angle detection unit that detects a steering angle related to the steering member, A steering mechanism for turning the steered wheels in a state of being mechanically separated from a steering member, a steered angle detecting unit for detecting a steered angle related to the steered wheels, and a behavior of the vehicle A behavior information acquisition unit that acquires behavior information, and a steering angle ratio setting unit that sets a steering angle ratio that is a ratio of the steering angle to the steering angle, and the steering angle ratio setting unit includes the steering angle The most important feature is that the ratio is set based on the behavior information acquired by the behavior information acquisition unit.

  According to the invention according to (1), since the steering angle ratio is set based on the behavior information of the vehicle, it is possible to realize setting of an appropriate steering angle ratio with a simple configuration.

  The invention according to (2) is the invention according to (1), in which the rudder angle ratio setting unit has a large value related to the behavior information obtained by obtaining the rudder angle ratio by the behavior information obtaining unit. It is characterized in that the characteristic is set to become larger as it becomes.

  According to the invention according to (2), since the steering angle ratio is set to a characteristic that increases as the value related to the behavior information increases, the steering angle with respect to the steering angle is reduced at a stage where the driver performs a gentle steering. The driver's responsiveness related to the change can be improved. Further, it is possible to avoid a situation in which the behavior of the vehicle falls into an under-steer tendency at a stage where the driver steers relatively steeply.

  The invention according to (3) is the invention according to (1), further comprising a lateral acceleration detection unit for detecting lateral acceleration of the vehicle, wherein the behavior information acquisition unit is the vehicle by the lateral acceleration detection unit. A detected value related to the lateral acceleration of the vehicle is acquired as a value related to the behavior information.

  The invention according to (4) is the invention according to (1), further comprising a vehicle speed detection unit that detects the speed of the vehicle, wherein the behavior information acquisition unit is detected by the steering angle detection unit. A predicted value related to a lateral acceleration of the vehicle based on a steering angle and the speed of the vehicle detected by the vehicle speed detector is acquired as a value related to the behavior information.

  The invention according to (5) is the invention according to (1), wherein the rudder angle ratio setting unit gradually increases the rudder angle ratio until the value related to the behavior information reaches a first predetermined value. The steering angle ratio is set to be substantially constant until the value related to the behavior information reaches the second predetermined value larger than the first predetermined value from the first predetermined value. The steering angle ratio is set to be gradually increased until the value related to the behavior information reaches the third predetermined value that is larger than the second predetermined value from the second predetermined value.

  According to the invention which concerns on (5), the driver's responsiveness concerning the change of the turning angle with respect to a steering angle can be improved in the stage in which the driver | operator performs slow steering. In addition, when the driver performs an intermediate steering operation (not slow or steep), the change of the steering angle with respect to the steering angle is linear, so that a smooth steering feeling without a sense of incongruity is given to the driver. Can do. Furthermore, it is possible to avoid a situation in which the behavior of the vehicle falls into an under-steer tendency at a stage where the driver is steered relatively steeply.

  According to the present invention, an appropriate steering angle ratio can be set with a simple configuration.

1 is a schematic configuration diagram of a vehicle steering apparatus according to an embodiment of the present invention. It is a figure showing the characteristic of the steering angle ratio set with respect to the change of a prediction lateral G value.

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 has a function (SBW mode) for generating a steering force by driving a steering motor 29 described later (SBW mode), for example, by driving the steering motor 29 when a steering reaction force motor 16 described later fails. An electric power steering (EPS) function (EPS mode) for generating an assisting force related to manual steering by the driver and, for example, a failure of the steering reaction force motor 16 and the steering motor 29, the driver Has a function (manual steering mode) to perform manual steering.

  In order to realize the above functions, 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 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 “steering mechanism” 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 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 via 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 engagement of the lock pin 39 with the tooth groove of the locking gear 33 is released, the clutch mechanism 19 is in a disconnected state in which the steering shaft 23 and the steered shaft 25 are disconnected. 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 an input system including 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. The steering angle sensor 41 corresponds to the “steering angle detector” of the present invention. 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 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 steering reaction force motor resolver 45 corresponds to the “steering angle detector” of the present invention.

  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.

  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 vehicle speed sensor 51 corresponds to the “vehicle speed detector” of the present invention. 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. The lateral acceleration sensor 55 corresponds to the “lateral acceleration detection unit” of the present invention.

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

  The control device 40 determines 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, such as the SBW mode and the EPS. A control signal for controlling the driving of the steering reaction force motor 16, the steering motor 29, and the electromagnetic solenoid 37 is generated in accordance with the function for determining either the mode or the manual steering mode and the determined operation mode. And a function of performing drive control of the steering reaction force motor 16, the steered motor 29, and the electromagnetic solenoid 37 based on the generated control signal.

  The control device 40 controls the steering reaction force motor 16 when the vehicle steering device 11 is operating in the SBW mode, so that the driver's hand holding the steering wheel 13 can be appropriately steered. It operates to convey such reaction force (response).

  The control device 40 also steers 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 device 11 is operating in the SBW mode. To work.

  Further, the control device 40 performs the 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. It operates to switch to either one of the separated states.

  More specifically, the control device 40 includes a predicted lateral G value calculation unit 61 and a steering angle ratio setting unit 63.

  The predicted lateral G value calculation unit 61 has a function of calculating a predicted value of lateral acceleration (predicted lateral G value) based on behavior information related to the behavior of the vehicle. More specifically, the predicted lateral G value calculation unit 61 is based on vehicle V speed (vehicle speed) information detected by the vehicle speed sensor 51 and steering angle information detected by the steering reaction force motor resolver 45. Lateral acceleration (predicted lateral G value) predicted to occur in

  The predicted lateral G value calculation unit 61 has a map that represents the relationship between the vehicle speed and the steering angle, and the predicted lateral G. This map can be appropriately set by, for example, experimental measurement or simulation. The predicted lateral G value calculated by the predicted lateral G value calculation unit 61 is sent to the steering angle ratio setting unit 63. The predicted lateral G value calculation unit 61 corresponds to the “behavior information acquisition unit” of the present invention.

The steering angle ratio setting unit 63 has a function of setting a steering angle ratio that is a ratio of a steering angle to a steering angle. More specifically, the rudder angle ratio setting unit 63 sets the rudder angle ratio to a characteristic that increases as the measured lateral G value increases. In particular, the steering angle ratio setting unit 63 is set to a characteristic that increases as the predicted lateral G value calculated by the predicted lateral G value calculating unit 61 increases (the first predicted lateral G range R1 shown in FIG. 2 and The third predicted lateral G range R3).
Note that the steering angle ratio AR0 shown in FIG. 2 is a mechanical steering angle ratio when the steering shaft 23 and the steered shaft 25 are in the coupled state.

  Here, the characteristics of the steering angle ratio set for the change in the predicted lateral G value will be described with reference to FIG. In the first predicted lateral G range R1 where the predicted lateral G value reaches from zero to the first predetermined value G1, the steering angle ratio shows a characteristic that gradually increases from AR1 to AR2. According to the first predicted lateral G range R1, it is possible to improve the driver's responsiveness related to the change in the turning angle with respect to the steering angle in a stage where the driver performs a slow steering.

  Further, in the second predicted lateral G range R2 in which the predicted lateral G value reaches the second predetermined value G2 from the first predetermined value G1, the steering angle ratio maintains a substantially constant value AR2. According to the second predicted lateral G range R2, there is no sense of incongruity because the change in the turning angle with respect to the steering angle is linear when the driver performs an intermediate steering operation (not slow or steep). A smooth steering feeling can be given to the driver.

  Further, in the third predicted lateral G range R3 from the second predetermined value G2 to the third predetermined value G3, the steering angle ratio gradually increases linearly from AR2 to AR3. Show. According to the third predicted lateral G range R3, the vehicle V is increased by increasing the rudder angle ratio, that is, by increasing the ratio of the steered angle to the steered angle in a stage where the driver performs relatively steep steering. It is possible to avoid the situation where the behavior of the vehicle falls into an under-steer tendency.

  In the fourth predicted lateral G range R4 in which the predicted lateral G value exceeds the third predetermined value G3, in principle, the steering angle ratio has a characteristic of maintaining a substantially constant value AR3.

  Next, the operation of the control device 40 when the operation mode of the vehicle steering device 11 is the SBW mode will be described. The control device 40 eliminates the deviation between the steering angle and the turning angle based on the steering angle information detected by the steering reaction force motor resolver 45 and the turning angle information detected by the turning motor resolver 47. Considering this, the stroke (target stroke) of the rack shaft 27 as a target is set. The control device 40 performs drive control of the steered motor 29 so that the rack shaft 27 is operated by the set target stroke.

  Further, the control device 40 controls the steering shaft 23 based on the steering angle information detected by the steering reaction force motor resolver 45, the steering information detected by the steering torque sensor 43, and the vehicle speed information detected by the vehicle speed sensor 51. The target steering reaction force to be given to is set. The control device 40 performs drive control of the steering reaction force motor 16 so as to realize the set target steering reaction force.

  However, the control device 40, for example, when the vehicle speed of the vehicle V is zero and the driver performs an operation of quickly turning off the steering wheel 13 (a case where the so-called stationary operation is performed quickly), the target steering reaction force. The steering follow-up control that simulates the feeling of being heavyly caught by the driver's hand is performed by setting.

  In particular, in the vehicle steering device 11 according to the embodiment of the present invention, the steering angle ratio setting unit 63 of the control device 40 is configured to switch the steering angle based on the predicted lateral G value calculated based on the vehicle speed and the steering angle. The steering angle ratio, which is the ratio of the steering angles, is set.

Here, the steering angle ratio setting unit 63 of the control device 40 sets the steering angle ratio based on the measured lateral G value, preferably based on the predicted lateral G value, mainly for the following reason.
That is, first, the lateral G value including both the actual lateral G value and the predicted lateral G value has a high correlation with the vehicle speed and the steering angle that have been conventionally used as parameters when the steering angle ratio is variably controlled. This is because it is suitable as independent information including information on the vehicle speed and the steering angle. Second, since the predicted lateral G value can suppress a time delay compared to the actually measured lateral G value detected by the lateral acceleration sensor 55, variable control of the steering angle ratio that requires high responsiveness. It is because it is suitable to apply to the case concerning.

To supplement the second reason, the measured lateral G value inevitably includes a time delay as information representing the behavior of the vehicle V, so that it can be used for variable control of the steering angle ratio that requires high responsiveness. In such cases, its use was avoided. On the other hand, the predicted lateral G value can be quickly calculated when the vehicle speed and the steering angle are acquired.
According to the studies by the present inventors, it has been found that it is preferable to use the predicted lateral G value in a case related to variable control of the steering angle ratio that requires high responsiveness.

  In addition, the predicted lateral G value does not include the influence of disturbance (for example, the influence caused by the friction coefficient of the traveling road surface, the cross wind, etc. on the vehicle V) unlike the measured lateral G value. For this reason, when the rudder angle ratio is set based on the predicted lateral G value, it is stable and does not fluctuate according to the influence of disturbance, compared to the case where the rudder angle ratio is set based on the actual lateral G value. Variable steering angle ratio control can be realized.

[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), a steering wheel (steering member) 13 that is operated when the steered wheels 21a and 21b of the vehicle V are steered, and a steering wheel (steering) Steering angle detectors 41 and 45 for detecting a steering angle related to the member 13 and a steering mechanism for turning the steered wheels 21a and 21b while being mechanically separated from the steering wheel (steering member) 13. 17, 25, 27, 29, steered angle detectors 47, 49 for detecting the steered angles associated with the steered wheels 21a, 21b, and a predicted lateral G value calculating unit (for acquiring behavior information relating to the behavior of the vehicle V) Behavior information acquisition unit) 61 and a steering angle ratio setting unit 63 that sets a steering angle ratio that is a ratio of a steering angle to a steering angle.
The rudder angle ratio setting unit 63 sets the rudder angle ratio based on the value (measured lateral G value or predicted lateral G value) related to the behavior information acquired by the predicted lateral G value calculation unit (behavior information acquisition unit) 61. .

According to the vehicle steering device 11 based on the first aspect (corresponding to claim 1), the steering angle ratio is set based on the value (actually measured lateral G value or predicted lateral G value) related to the behavior information. A simple steering angle ratio can be set with a simple configuration.
Incidentally, the lateral G value including both the actual lateral G value and the predicted lateral G value has a high correlation with the vehicle speed and the steering angle that have been conventionally used as parameters when the steering angle ratio is variably controlled. It is suitable as independent information including the information concerning.

  In the vehicle steering apparatus 11 based on the second aspect (corresponding to claim 2), the steering angle ratio setting unit 63 acquires the steering angle ratio by the predicted lateral G value calculation unit (behavior information acquisition unit) 61. A configuration may be adopted in which the characteristic is set to increase as the value (actually measured lateral G value or predicted lateral G value) related to the behavior information increases.

  According to the vehicle steering apparatus 11 based on the second aspect (corresponding to claim 2), the steering angle ratio increases as the value (actually measured lateral G value or predicted lateral G value) related to the behavior information increases ( Since the characteristic is set to be quick, the driver's responsiveness related to the change in the turning angle with respect to the steering angle can be improved at the stage where the driver performs a slow steering. In addition, it is possible to avoid a situation in which the behavior of the vehicle V falls into an under-steer tendency at a stage where the driver is steered relatively steeply.

  The vehicle steering apparatus 11 based on the third aspect (corresponding to claim 3) includes a lateral acceleration detection unit 55 that detects the lateral acceleration of the vehicle V, and includes a predicted lateral G value calculation unit (behavior information acquisition unit). 61 may adopt a configuration in which the lateral acceleration detection unit 55 acquires a detection value (measured lateral G value) related to the lateral acceleration of the vehicle V as a value related to behavior information.

  According to the vehicle steering apparatus 11 based on the third aspect (corresponding to claim 3), the steering angle ratio is set based on the detected value (actual lateral G value) related to the lateral acceleration of the vehicle V. Similar to the vehicle steering apparatus 11 based on the first aspect (corresponding to claim 1), the setting of an appropriate steering angle ratio can be realized with a simple configuration.

  The vehicle steering apparatus 11 based on the fourth aspect (corresponding to claim 4) includes a vehicle speed detection unit 51 that detects the speed of the vehicle V, and a predicted lateral G value calculation unit (behavior information acquisition unit) 61 The predicted value (predicted lateral G value) related to the lateral acceleration of the vehicle based on the steering angle detected by the steering angle detecting units 41 and 45 and the speed of the vehicle V detected by the vehicle speed detecting unit 51 is related to the behavior information. You may employ | adopt the structure acquired as a value.

  According to the vehicle steering apparatus 11 based on the fourth aspect (corresponding to claim 4), the steering angle ratio is set based on the predicted value (predicted lateral G value) related to the lateral acceleration of the vehicle V. Compared with the vehicle steering device 11 based on the third aspect (corresponding to claim 1), it is suitable for a case related to variable control of the steering angle ratio that requires high responsiveness, and according to the influence of disturbance. A stable and good steering angle ratio variable control that does not fluctuate can be realized.

  In the vehicle steering apparatus 11 based on the fifth aspect (corresponding to claim 5), the steering angle ratio setting unit 63 has a value (predicted lateral G value) related to the behavior information reaching the first predetermined value G1. Until the steering angle ratio is set to gradually increase, the value (predicted lateral G value) related to the behavior information reaches from the first predetermined value G1 to the second predetermined value G2 that is larger than the first predetermined value G1. Sets the steering angle ratio to be substantially constant, and the value related to the behavior information (predicted lateral G value) is changed from the second predetermined value G2 to the third predetermined value G3 larger than the second predetermined value G2. You may employ | adopt the structure which sets to gradually increase a steering angle ratio until it reaches.

  According to the vehicle steering device 11 based on the fifth aspect (corresponding to claim 5), at the stage where the driver performs the slow steering, the driver's responsiveness related to the change of the turning angle with respect to the steering angle is obtained. Can be improved. In addition, when the driver performs an intermediate steering operation (not slow or steep), the change of the steering angle with respect to the steering angle is linear, so that a smooth steering feeling without a sense of incongruity is given to the driver. Can do. Furthermore, it is possible to avoid a situation in which the behavior of the vehicle V falls into an under-steer tendency when the driver is steered relatively steeply.

[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.

  Further, in the description according to the embodiment of the present invention, the vehicle steering apparatus 11 has been described by taking the example of having the SBW mode, the EPS mode, and the manual steering mode as its operation mode. However, the present invention is not limited to this example. It is not limited to. As the operation mode, the present invention may be applied to a vehicle steering apparatus having only the SBW mode (the steering shaft 23 and the steered shaft 25 are always disconnected).

  Further, in the description according to the embodiment of the present invention, the vehicle speed sensor 51 is exemplified and described as the “vehicle speed detection unit” according to the present invention, but the present invention is not limited to this example. Instead of the vehicle speed sensor 51, a wheel speed sensor that detects the rotational speed of the wheel may be employed as the “vehicle speed detection unit” according to the present invention. In this case, the control device 40 may calculate the speed of the vehicle V based on the wheel speed signal detected by the wheel speed sensor.

  Finally, in the description according to the embodiment of the present invention, an example in which the predicted lateral G value is calculated based on the vehicle speed and the steering angle has been described, but the present invention is not limited to this example. The predicted lateral G value calculation unit 61 calculates a lateral acceleration (predicted lateral G value) that is predicted to occur in the vehicle V based on, for example, the radius of curvature of the travel route obtained through the travel route guidance information of the navigation device and the vehicle speed. You may employ | adopt the structure to do.

11 Steering device for vehicle 13 Steering wheel (steering member)
17 Steering device (steering mechanism)
21a, 21b Steering wheel 25 Steering shaft (steering mechanism)
27 Rack shaft (steering mechanism)
29 Steering motor (steering mechanism)
41 Steering angle sensor (steering angle detector)
45 Steering reaction force motor resolver (steering angle detector)
51 Vehicle speed sensor (vehicle speed detector)
55 Lateral acceleration sensor (lateral acceleration detector)
61 Predicted lateral G value calculation unit (behavior information acquisition unit)
63 Rudder angle ratio setting part V Vehicle

Claims (5)

A steering member operated when turning the steered wheels of the vehicle;
A steering angle detector that detects a steering angle of the steering member;
A steering mechanism for steering the steered wheels in a state of being mechanically separated from the steering member;
A turning angle detector for detecting a turning angle associated with the steered wheel;
A behavior information acquisition unit for acquiring behavior information relating to the behavior of the vehicle;
A steering angle ratio setting unit that sets a steering angle ratio that is a ratio of the steering angle to the steering angle, and
The rudder angle ratio setting unit sets the rudder angle ratio based on the behavior information acquired by the behavior information acquisition unit,
A vehicle steering apparatus characterized by the above. The vehicle steering device according to claim 1,
The rudder angle ratio setting unit sets the rudder angle ratio to a characteristic that increases as the value related to the behavior information acquired by the behavior information acquisition unit increases.
A vehicle steering apparatus characterized by the above. The vehicle steering device according to claim 1,
A lateral acceleration detector for detecting the lateral acceleration of the vehicle;
The behavior information acquisition unit acquires a detection value related to the lateral acceleration of the vehicle by the lateral acceleration detection unit as a value related to the behavior information.
A vehicle steering apparatus characterized by the above. The vehicle steering device according to claim 1,
A vehicle speed detector for detecting the speed of the vehicle;
The behavior information acquisition unit relates a predicted value related to a lateral acceleration of the vehicle based on the steering angle detected by the steering angle detection unit and the speed of the vehicle detected by the vehicle speed detection unit to the behavior information. Get as value,
A vehicle steering apparatus characterized by the above. The vehicle steering apparatus according to any one of claims 1, 3, and 4,
The rudder angle ratio setting unit
Until the value relating to the behavior information reaches a first predetermined value, the steering angle ratio is set to gradually increase,
The steering angle ratio is set to be substantially constant until the value related to the behavior information reaches the second predetermined value larger than the first predetermined value from the first predetermined value,
The steering angle ratio is set to be gradually increased until the value related to the behavior information reaches the third predetermined value that is larger than the second predetermined value from the second predetermined value.
A vehicle steering apparatus characterized by the above.

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