WO2019189095A1 - Système de direction et véhicule pourvu de celui-ci - Google Patents

Système de direction et véhicule pourvu de celui-ci Download PDF

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Publication number
WO2019189095A1
WO2019189095A1 PCT/JP2019/012713 JP2019012713W WO2019189095A1 WO 2019189095 A1 WO2019189095 A1 WO 2019189095A1 JP 2019012713 W JP2019012713 W JP 2019012713W WO 2019189095 A1 WO2019189095 A1 WO 2019189095A1
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WO
WIPO (PCT)
Prior art keywords
steering
vehicle
brake
toe angle
unit
Prior art date
Application number
PCT/JP2019/012713
Other languages
English (en)
Japanese (ja)
Inventor
聡 宇都宮
教雄 石原
佑介 大畑
大場　浩量
Original Assignee
Ntn株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018059167A external-priority patent/JP2019171905A/ja
Priority claimed from JP2018059169A external-priority patent/JP2019171907A/ja
Application filed by Ntn株式会社 filed Critical Ntn株式会社
Publication of WO2019189095A1 publication Critical patent/WO2019189095A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G7/00—Pivoted suspension arms; Accessories thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D6/00—Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D7/00—Steering linkage; Stub axles or their mountings
    • B62D7/06—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins
    • B62D7/14—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering
    • B62D7/15—Steering linkage; Stub axles or their mountings for individually-pivoted wheels, e.g. on king-pins the pivotal axes being situated in more than one plane transverse to the longitudinal centre line of the vehicle, e.g. all-wheel steering characterised by means varying the ratio between the steering angles of the steered wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force

Definitions

  • the present invention relates to a steering system and a vehicle equipped with the same, and relates to a technique for improving vehicle safety and reducing driver fatigue.
  • the steering wheel and the steering device are mechanically connected, and both ends of the steering device are connected to the left and right wheels by tie rods. Therefore, the turning angle of the left and right wheels due to the movement of the handle is determined by the initial setting.
  • the geometry of the vehicle is (1) “parallel geometry” in which the left and right wheels have the same turning angle, and (2) the turning inner wheel angle is turned larger than the turning outer wheel angle in order to make the turning center one place. Ackermann geometry is known.
  • Patent Documents 1 and 2 have been proposed regarding a mechanism in which the steering geometry is variable in accordance with the traveling state.
  • the steering geometry is changed by relatively changing the knuckle arm and the joint position.
  • Patent Document 2 two motors are used, and both the toe angle and the camber angle can be tilted to an arbitrary angle.
  • Patent Document 3 proposes a four-wheel independent steering mechanism.
  • the Ackermann geometry is the difference in rudder angle between the left and right wheels so that each wheel turns around a common point in order to smoothly turn the vehicle when turning at low speeds where the centrifugal force acting on the vehicle can be ignored. Is set. However, in high-speed turning where the centrifugal force cannot be ignored, it is desirable that the wheels generate a cornering force in a direction that balances with the centrifugal force. Therefore, the parallel geometry is preferable to the Ackermann geometry.
  • Patent Document 1 the knuckle arm and the joint position are relatively changed to change the steering geometry.
  • a motor actuator that obtains such a large force that the vehicle geometry is changed in such a portion. It is very difficult due to space constraints. Further, the change in the wheel angle due to the change at this position is small, and in order to obtain a large effect, it is necessary to change it greatly, that is, to move it greatly.
  • Patent Document 2 since two motors are used, not only the cost increases due to the increase in the number of motors, but also the control becomes complicated.
  • the conventional mechanism having an auxiliary turning function has a complicated structure because it aims to arbitrarily change the toe angle or the camber angle of the wheel in the vehicle.
  • it is difficult to ensure rigidity because of the large number of components, and the entire mechanism is increased in size and weight to ensure rigidity.
  • the toe angle of the wheel cannot be changed during traveling.
  • it is difficult to ensure rigidity because of the large number of components, and the entire mechanism is increased in size and weight to ensure rigidity.
  • the driver steps on the brake, but a weak woman or an elderly person cannot obtain a sufficient braking force and the braking distance may be extended.
  • the driver's fatigue may increase in a driving situation where the brakes must be frequently applied, such as mountain roads or urban areas.
  • the behavior of the vehicle tends to be unstable, such as skidding, especially in a situation where the coefficient of friction of the road surface is low such as rainy weather or snowy road.
  • An object of the present invention is to provide a steering system capable of shortening the braking distance of a vehicle at the time of brake braking, improving the straight running stability at the time of brake braking, and stabilizing the vehicle behavior at the time of brake braking, and a vehicle equipped with the steering system. Is to provide.
  • a steering system 101 of the present invention is a steering system provided in a vehicle 100, A first steering device 11 for steering the wheels 9 of the vehicle 100 in accordance with a steering amount command output by the steering command devices 200 and 200A;
  • a second part has a mechanism part 150a for individually steering left and right wheels 9 by driving a steering actuator 5 provided in a tire housing 105 of the vehicle 100, and a control part 150b for controlling the steering actuator 5.
  • Steering device 150 of A vehicle information detection unit 110 that detects vehicle information including brake pedal force
  • the controller 150b has toe angle control means 37A for controlling the steering actuator 5 so that the left and right wheels 9, 9 have a predetermined toe angle according to the brake pedal force.
  • the predetermined toe angle is an arbitrary toe angle determined by design or the like, and is determined by obtaining an appropriate toe angle by, for example, testing and / or simulation.
  • the first steering device 11 steers the wheels 9 and 9 in accordance with the steering amount command output by the steering command devices 200 and 200A.
  • the steering command devices 200 and 200A for example, a driver's steering wheel or an automatic steering command device can be applied. Adjustment of the direction of the vehicle 100 by such a steering command device or the like can be performed similarly to a conventional vehicle.
  • the second steering device 150 drives the steering actuator 5 provided in the tire housing 105 to steer the left and right wheels 9 and 9 individually.
  • the toe angle control means 37A controls the steering actuator 5 so that the left and right wheels 9, 9 have a predetermined toe angle according to the brake depression force.
  • the toe angle control means 37A controls the steering actuator 5 so that the toe angle increases as the brake pedal force increases.
  • the resistance between the tire and the road surface can be increased to assist the braking force.
  • the straight running stability at the time of brake braking can be improved, and the fluctuation of the vehicle can be suppressed. Therefore, it is possible to shorten the braking distance of the vehicle at the time of brake braking, improve the straight running stability at the time of braking, and stabilize the vehicle behavior at the time of braking.
  • the vehicle 100 includes a brake device 21 that brakes the vehicle 100 according to the brake pedal force, and the toe angle control unit 37A gives the vehicle 100 an auxiliary braking force that assists the braking force by the brake device 21. It may be a thing. According to this configuration, the size of the brake device 21 can be set to be compact. In addition, for example, when an abnormality occurs in the brake device 21 and a desired braking force cannot be generated, the auxiliary braking force is applied to the vehicle by using the second steering device 150 that individually steers the left and right wheels 9 and 9. 100.
  • the vehicle information further includes a vehicle speed
  • the controller 150b may include an emergency braking state toe angle control unit 36 that performs a toe angle control on the steering actuator 5 when a sudden brake command is output from the brake command unit.
  • the brake command means is an automatic brake device or a brake pedal force sensor.
  • the automatic brake device outputs the "sudden brake command" when it is judged that the collision condition has been satisfied by recognizing the surrounding conditions of other vehicles, obstacles, etc. from sensors such as cameras or millimeter wave radars.
  • the brake pedal force sensor is a sensor that is output in accordance with the brake pedal force of the brake operation means by the driver.
  • the brake pedal force (brake force) that is output from the sensor is equal to or greater than a threshold value, and the amount of change in the brake pedal force is a threshold value. In this case, the brake pedal force is the “sudden brake command”.
  • the emergency braking state toe angle control means 36 When the vehicle 100 is equipped with an automatic brake device, the emergency braking state toe angle control means 36 performs toe angle control when a sudden brake command is output from either or both of the automatic brake device and the brake pedal force sensor. Do. When the vehicle 100 is not equipped with an automatic brake device, the emergency braking state toe angle control means 36 performs toe angle control when a sudden braking command is output from the brake pedal force sensor.
  • the emergency braking state toe angle control means 36 in the control unit 150b performs toe angle control on the steering actuator 5.
  • the rotational resistance of each wheel is increased to shorten the braking distance and improve the vehicle safety, compared to when each wheel is in a straight traveling state (toe angle is zero degrees), for example. be able to.
  • the emergency braking state toe angle control means 36 may use the toe angle as a maximum angle.
  • the braking resistance can be further shortened by increasing the rotational resistance of the left and right wheels 9, 9 to the maximum.
  • the control system can be simplified.
  • the emergency braking state toe angle control means 36 may determine the toe angle according to the vehicle speed.
  • the relationship between the vehicle speed and the toe angle is determined using, for example, a map or an arithmetic expression. According to this configuration, it is possible to prevent the wheel 9 from being undesirably locked and to prevent the braking force from being lowered. This is because when the toe angle is suddenly changed from the high speed range, the wheels are undesirably locked and the tires slip, which may reduce the braking force.
  • the control unit 150b includes a determination unit 33 that determines whether or not the emergency braking state is based on the vehicle speed and the brake pedal force, and the emergency braking state toe angle control unit 36 uses the determination unit 33 to determine the emergency state.
  • the steering actuator 5 may be controlled so that a predetermined toe angle is obtained.
  • the predetermined toe angle is a toe-in or toe-out toe angle arbitrarily determined by design or the like, and is determined by obtaining an appropriate toe angle by, for example, testing and / or simulation.
  • the vehicle 100 includes a brake device 21 that brakes the vehicle 100 according to the brake depression force, and the emergency braking state toe angle control means 36 uses an auxiliary braking force that assists the braking force by the brake device 21 as described above. It may be given to the vehicle 100. According to this configuration, for example, when an abnormality occurs in the brake device 21 and a desired braking force cannot be generated, the auxiliary braking is performed using the second steering device 150 that individually steers the left and right wheels 9 and 9. Power can be applied to the vehicle 100.
  • the mechanism 150a of the second steering device 150 is A hub unit body 2 having a hub bearing 15 for supporting the wheel 9; A unit support member 3 provided on the undercarriage frame component 6 of the suspension device 12 and rotatably supporting the hub unit body 2 about a turning axis A extending in the vertical direction; The steering unit 5 may be provided to rotate the hub unit body 2 about the turning axis A.
  • the hub unit body 2 including the hub bearing 15 that supports the wheels 9 can be freely rotated around the turning axis A within a certain range by driving the steering actuator 5. For this reason, steering can be performed independently for each wheel, and the toe angle of the wheel 9 can be arbitrarily changed according to the traveling state of the vehicle 100.
  • the rudder angle difference between the left and right wheels 9, 9 can be changed according to the traveling speed.
  • the steering geometry can be changed during traveling, such as parallel geometry for turning in a high speed region and Ackermann geometry for turning in a low speed region.
  • the wheel angle can be arbitrarily changed during traveling, it is possible to improve the motion performance of the vehicle 100 and travel stably and safely.
  • the steering angle of the left and right steered wheels the turning radius of the vehicle 100 in turning traveling can be reduced and the turning performance can be improved.
  • the control unit 150b of the second steering device 150 outputs an auxiliary steering control unit 151 that outputs a current command signal according to a given steering angle command signal, and a current command signal input from the auxiliary steering control unit 151.
  • the actuator drive control units 31R and 31L that drive and control the steering actuator 5 by outputting a current corresponding to the above may be provided.
  • the auxiliary steering control unit 151 outputs a current command signal corresponding to the given steering angle command signal.
  • the actuator drive control units 31R and 31L drive and control the steering actuator 5 by outputting a current corresponding to the current command signal input from the auxiliary steering control unit 151. Therefore, it is possible to arbitrarily change the wheel angle in addition to steering by a driver's steering wheel operation or the like.
  • the mechanism 150a of the second steering device 150 may steer either one or both of the left and right front wheels 9, 9 and the left and right rear wheels 9, 9.
  • the mechanism portion 150a When the mechanism portion 150a is applied to the left and right front wheels 9, 9, the direction of the wheels 9 is steered together with the entire hub unit by a driver's handle operation or the like.
  • auxiliary steering with a slight angle is added to this steering. Can be performed independently for each wheel.
  • the mechanism portion 150a is applied to the left and right rear wheels 9, 9, 9, the entire hub unit is not steered, but the auxiliary steering function enables steering at a slight angle independently for each wheel, like the front wheels.
  • the vehicle according to the present invention includes the steering system having the above-described configuration. Therefore, each effect mentioned above about the steering system of this invention is acquired.
  • FIG. 1 is a diagram schematically illustrating a conceptual configuration of a steering system according to a first embodiment of the present invention.
  • FIG. 5 is a longitudinal sectional view showing a configuration of a mechanism portion of a second steering device and its surroundings in the steering system of FIG. 1.
  • FIG. 3 is a horizontal cross-sectional view showing a configuration of a mechanism portion and the like of the second steering device of FIG.
  • FIG. 10 It is a perspective view which shows the external appearance of the mechanism part of the 2nd steering apparatus of FIG. It is a disassembled front view of the mechanism part of the 2nd steering apparatus of FIG. It is a side view of the mechanism part of the 2nd steering apparatus of FIG. It is a top view of the mechanism part of the 2nd steering apparatus of FIG. It is the VIII-VIII sectional view taken on the line of FIG. It is a block diagram which shows the conceptual structure of the steering system of FIG. It is a graph which shows the relationship between brake pedal force and toe angle. 10 is a flowchart showing step by step processing for controlling a toe angle in a control unit of a second steering device of the steering system of FIG. 9.
  • FIG. 15 is a flowchart showing step by step processing for controlling a toe angle in the control unit of the second steering device of the steering system of FIG. 14.
  • FIG. It is a figure which shows schematically the conceptual structure of the steering system which concerns on 3rd Embodiment of this invention. It is a figure which shows schematically the conceptual structure of the steering system which concerns on 4th Embodiment of this invention.
  • FIG. 1 is a diagram schematically showing a conceptual configuration of a vehicle 100 such as an automobile equipped with a steering system 101 according to this embodiment.
  • the vehicle 100 is a four-wheel vehicle having left and right wheels 9 and 9 as front wheels and left and right wheels 9 and 9 as rear wheels, and the driving method is any of front wheel drive, rear wheel drive, and four wheel drive. It may be.
  • the steering system 101 is a system for steering the vehicle 100, and includes a first steering device 11, a second steering device 150 that is a steering device that individually steers left and right wheels 9, 9, and a vehicle. And an information detection unit 110.
  • the first steering device 11 is a device that steers the left and right wheels 9 and 9 that are the steering wheels of the vehicle 100 by a driver's operation with respect to a steering command device such as the handle 200.
  • the first steering device 11 is a front wheel steering type. ing.
  • the second steering device 150 is a device that performs auxiliary steering by control according to the state of the vehicle 100, and includes a mechanism unit 150a and a control unit 150b.
  • the mechanism part 150a is a mechanism provided for each of the wheels 9 and 9 that are targets of auxiliary steering.
  • the mechanism 150a is provided in the tire housing 105 of the vehicle 100, and individually steers the wheels 9 by driving the steering actuator 5 (FIG. 2).
  • the control unit 150b performs control based on vehicle information representing the state of the vehicle 100 detected by the vehicle information detection unit 110.
  • the steering system 101 The left and right wheels 9 and 9 serving as the front wheels of the vehicle 100 are mechanically interlocked, and the left and right wheels 9 and 9 serving as the front wheels of the vehicle 100 are connected to the left and right wheels 9 according to the steering amount command output by the steering command device.
  • the first steering device 11 that is steered by changing the angles of the knuckles 6 and 6 that are left and right underbody frame parts of the suspension device 12 on which the suspension device 9 is installed, By driving auxiliary steering actuators (steering actuators 5 (FIG. 2)) provided for the left and right wheels 9, 9, the wheels 9, 9 with respect to the knuckles 6, 6 as the underbody frame parts are driven.
  • the vehicle information detection unit 110 is a means for detecting the state of the vehicle 100 and refers to a group of various sensors.
  • the vehicle information detected by the vehicle information detection unit 110 is transferred to the control unit 150b of the second steering device 150 via the main ECU 130.
  • the ECU 130 is a control device that performs overall cooperative control or overall control of the vehicle 100, and is also referred to as a VCU.
  • the first steering device 11 is a system for steering the left and right wheels 9 and 9 that are the front wheels of the vehicle 100 in conjunction with each other in response to an input to the steering wheel 200 by the driver, and includes a steering shaft 32, a rack and pinion (see FIG. (Not shown) and a tie rod 14 or the like, which has a known mechanical configuration.
  • the steering shaft 32 When the driver inputs rotation to the handle 200, the steering shaft 32 also rotates in conjunction with it.
  • the tie rod 14 connected to the steering shaft 32 is moved in the vehicle width direction by the rack and pinion, so that the direction of the wheels 9 is changed, and the left and right wheels 9, 9 are steered in conjunction with each other. It is possible.
  • second steering device 150 can steer the left and right wheels 9 and 9 independently.
  • a right wheel hub unit 1R and a left wheel hub unit 1L are provided as a mechanism portion 150a of the second steering device 150.
  • the right wheel hub unit 1 ⁇ / b> R and the left wheel hub unit 1 ⁇ / b> L steer the wheels 9 and 9 by a steering actuator 5 (FIG. 2) provided in the tire housing 105.
  • the mechanism portion 150a of the second steering device 150 includes the right wheel hub unit 1R and the left wheel hub unit 1L as described above, and both the right wheel hub unit 1R and the left wheel hub unit 1L are shown in FIG. It is configured as a functional hub unit 1.
  • the hub unit 1 includes a hub unit main body 2, a unit support member 3, a rotation allowable support component 4, and a steering actuator 5.
  • the unit support member 3 is provided integrally with a knuckle 6 that is a suspension frame part.
  • the actuator body 7 of the steering actuator 5 is provided on the inboard side of the unit support member 3, and the hub unit body 2 is provided on the outboard side of the unit support member 3.
  • the hub unit 1 (FIG. 2) mounted on the vehicle
  • the vehicle width direction outer side of the vehicle is referred to as an outboard side
  • the vehicle width direction center side of the vehicle is referred to as an inboard side.
  • the hub unit main body 2 and the actuator main body 7 are connected by a joint portion 8.
  • the joint portion 8 is provided with a boot (not shown) for waterproofing and dustproofing.
  • the hub unit body 2 is supported by the unit support member 3 via the rotation-allowing support parts 4 and 4 at two upper and lower positions so as to be rotatable around the turning axis A extending in the vertical direction.
  • the turning axis A is an axis different from the rotation axis O of the wheel 9, and is different from the kingpin axis that performs main steering.
  • the kingpin angle is set to 10 to 20 degrees for the purpose of improving the straight running stability of the vehicle traveling.
  • the hub unit 1 of this embodiment has an angle (axis) different from the kingpin angle. It has a steering shaft.
  • the wheel 9 includes a wheel 9a and a tire 9b.
  • the hub unit 1 (FIG. 2) of this embodiment is added to the steering of the left and right wheels 9, 9 as front wheels by the first steering device 11, and has a small angle ( As a mechanism for steering about ⁇ 5 deg), the knuckle 6 of the suspension device 12 is integrally provided.
  • the first steering device 11 is of a rack and pinion type, but any type of steering device may be used.
  • the strut suspension mechanism that directly fixes the shock absorber to the knuckle 6 is applied to the suspension device 12, a multi-link suspension mechanism or other suspension mechanisms may be applied.
  • the hub unit main body 2 includes a hub bearing 15 for supporting the wheels 9, an outer ring 16, and an arm portion 17 (FIG. 4) that is a steering force receiving portion described later.
  • the hub bearing 15 includes an inner ring 18, an outer ring 19, and rolling elements 20 such as balls interposed between the inner and outer rings 18, 19. 2).
  • the hub bearing 15 is an angular ball bearing in which the outer ring 19 is a fixed ring, the inner ring 18 is a rotating ring, and the rolling elements 20 are in a double row.
  • the inner ring 18 includes a hub ring portion 18a having a hub flange 18aa and constituting a race surface on the outboard side, and an inner ring portion 18b constituting a race surface on the inboard side.
  • the wheel 9a of the wheel 9 is bolted to the hub flange 18aa so as to overlap the brake rotor 21a.
  • the inner ring 18 rotates around the rotation axis O.
  • the outer ring 16 includes an annular portion 16a fitted to the outer peripheral surface of the outer ring 19, and a trunnion shaft-shaped mounting shaft portion that protrudes upward and downward from the outer periphery of the annular portion 16a. 16b, 16b.
  • Each attachment shaft portion 16 b is provided coaxially with the turning shaft center A.
  • each wheel 9 is provided with a brake 21 which is a brake device for braking the vehicle.
  • the brake 21 includes a brake rotor 21a and a brake caliper 21b.
  • the brake caliper 21b is mounted on two upper and lower brake caliper mounting portions 22 (FIG. 6) formed integrally with the outer ring 16 or the outer ring 19 so as to project into an arm shape.
  • each rotation-allowing support component 4 is composed of a rolling bearing.
  • a tapered roller bearing is applied as the rolling bearing.
  • the rolling bearing includes an inner ring 4a fitted to the outer periphery of the mounting shaft portion 16b, an outer ring 4b fitted to the unit support member 3, and a plurality of rolling elements 4c interposed between the inner and outer rings 4a and 4b.
  • the unit support member 3 includes a unit support member main body 3A and a unit support member combined body 3B.
  • a substantially ring-shaped unit support member assembly 3B is detachably fixed to the end of the unit support member main body 3A on the outboard side.
  • Partial concave spherical fitting hole forming portions 3a are respectively formed on the upper and lower portions of the side surface of the inboard side of the unit support member assembly 3B.
  • partial concave spherical fitting hole forming portions 3Aa are respectively formed in the upper and lower portions of the outboard side end of the unit support member main body 3A.
  • the unit support member combined body 3B is fixed to the outboard side end of the unit support member main body 3A, and the fitting hole forming portions 3a and 3Aa (FIG. 7) are combined with each other for each upper and lower portion.
  • a fitting hole is formed continuously around the entire circumference.
  • the outer ring 4b (FIG. 8) is fitted into this fitting hole.
  • the unit support member 3 is indicated by a one-dot chain line.
  • each mounting shaft portion 16 b in the outer ring 16 is formed with a female screw portion extending in the radial direction, and is provided with a bolt 23 that is screwed into the female screw portion.
  • a disc-like pressing member 24 is interposed on the end surface of the inner ring 4a, and a preload is applied to each rotation-allowing support component 4 by applying a pressing force to the end surface of the inner ring 4a by a bolt 23 that is screwed into the female screw portion. Giving. Thereby, the rigidity of each rotation permission support component 4 can be improved. Even when the weight of the vehicle acts on the hub unit, the initial preload is set so as not to be released.
  • the rolling bearing of the rotation-allowing support component 4 is not limited to the tapered roller bearing, and an angular ball bearing can be used depending on use conditions such as a maximum load. Even in that case, a preload can be applied in the same manner as described above.
  • the arm portion 17 is a portion serving as an action point for applying a steering force to the outer ring 19 of the hub bearing 15, and is integrated with a part of the outer periphery of the annular portion 16 a or a part of the outer periphery of the outer ring 19. Protrusively.
  • the arm portion 17 is rotatably connected to the linear motion output portion 25 a of the steering actuator 5 via the joint portion 8. As a result, when the linear motion output portion 25a of the steering actuator 5 advances and retreats, the hub unit body 2 rotates around the turning axis A (FIG. 2), that is, is steered.
  • the steering actuator 5 includes an actuator body 7 that rotates the hub unit body 2 about the turning axis A (FIG. 2).
  • the actuator body 7 converts a motor 26, a speed reducer 27 that decelerates the rotation of the motor 26, and a forward / reverse rotation output of the speed reducer 27 into a reciprocating linear motion of the linear motion output unit 25a.
  • a linear motion mechanism 25 a linear motion mechanism 25.
  • the motor 26 is, for example, a permanent magnet type synchronous motor, but may be a DC motor or an induction motor.
  • the reduction gear 27 can use a wrapping type transmission mechanism such as a belt transmission mechanism or a gear train, and a belt transmission mechanism is used in the example of FIG.
  • the reducer 27 includes a drive pulley 27a, a driven pulley 27b, and a belt 27c.
  • a drive pulley 27 a is coupled to the motor shaft of the motor 26, and a driven pulley 27 b is provided in the linear motion mechanism 25.
  • the driven pulley 27b is disposed in parallel to the motor shaft.
  • the driving force of the motor 26 is transmitted from the drive pulley 27a to the driven pulley 27b via the belt 27c.
  • the drive pulley 27a, the driven pulley 27b, and the belt 27c constitute a winding-type speed reducer 27.
  • a feed screw mechanism such as a slide screw or a ball screw, a rack and pinion mechanism, or the like can be used.
  • a feed screw mechanism using a trapezoidal screw slide screw is used. Since the linear motion mechanism 25 includes a feed screw mechanism that uses a sliding screw of the trapezoidal screw, the effect of preventing reverse input from the tire 9b can be enhanced.
  • the actuator body 7 including the motor 26, the speed reducer 27, and the linear motion mechanism 25 is assembled as a semi-assembly and is detachably attached to the case 6b with bolts or the like. A mechanism that directly transmits the driving force of the motor 26 to the linear motion mechanism 25 without using a reduction gear is also possible.
  • the case 6b is integrally formed with the unit support member main body 3A as a part of the unit support member 3.
  • the case 6 b is formed in a bottomed cylindrical shape, and is provided with a motor housing portion that supports the motor 26 and a linear motion mechanism housing portion that supports the linear motion mechanism 25.
  • a fitting hole for supporting the motor 26 at a predetermined position in the case is formed in the motor housing portion.
  • the linear motion mechanism accommodating portion is formed with a fitting hole for supporting the linear motion mechanism 25 at a predetermined position in the case, a through hole for allowing the linear motion output portion 25a to advance and retreat.
  • the unit support member main body 3A includes the case 6b, a shock absorber mounting portion 6c serving as a shock absorber mounting portion, and a steering device coupling serving as a coupling portion of the first steering device 11 (FIG. 3). Part 6d.
  • the shock absorber mounting portion 6c and the steering device coupling portion 6d are also integrally formed with the unit support member main body 3A.
  • a shock absorber mounting portion 6c is formed on the upper portion of the outer surface portion of the unit support member main body 3A so as to protrude.
  • a steering device coupling portion 6d is formed on the side surface portion of the outer surface portion of the unit support member main body 3A so as to protrude.
  • vehicle information detection section 110 detects vehicle information and outputs it to ECU 130.
  • the vehicle information detection unit 110 includes a vehicle speed detection unit 111, a steering angle detection unit 112, a vehicle height detection unit 113, an actual yaw rate detection unit 114, an actual lateral acceleration detection unit 115, an accelerator information detection unit (accelerator pedal sensor) 116, and a brake.
  • An information detection unit (brake pedal sensor) 117 is provided.
  • the vehicle speed detection unit 111 detects the speed of the vehicle (vehicle speed) based on the output of a sensor (not shown) such as a speed sensor attached to the inside of a transmission provided in the vehicle, and sends vehicle speed information (simply “ It is also called “vehicle speed”.
  • the steering angle detection unit 112 detects a steering angle (steering angle) based on the output of a sensor (not shown) such as a resolver attached to a motor unit included in the first steering device 11, for example, and sends the steering angle to the ECU 130.
  • Information also simply referred to as “steering angle” or “wheel angle” is output.
  • the vehicle height detection unit 113 measures the distance between the chassis of the vehicle 100 (FIG. 1) and the ground using a laser displacement meter, or the angle of the upper arm or lower arm (not shown) in the suspension device 12 (FIG. 1) of the vehicle 100.
  • the vehicle height of each wheel 9 (FIG. 1) to be steered by the second steering device 150 is detected by a method of detecting the angle with an angle sensor. Then, the vehicle height detection unit 113 outputs the detected vehicle height to the ECU 130 as vehicle height information.
  • the actual yaw rate detection unit 114 detects the actual yaw rate based on the output of a sensor such as a gyro sensor attached to the vehicle 100 (FIG. 1), for example, and outputs the actual yaw rate information to the ECU 130.
  • a sensor such as a gyro sensor attached to the vehicle 100 (FIG. 1), for example, and outputs the actual yaw rate information to the ECU 130.
  • the actual lateral acceleration detection unit 115 detects actual lateral acceleration based on the output of a sensor such as a gyro sensor attached to the vehicle 100 (FIG. 1), for example, and outputs actual lateral acceleration information to the ECU 130.
  • a sensor such as a gyro sensor attached to the vehicle 100 (FIG. 1), for example, and outputs actual lateral acceleration information to the ECU 130.
  • the accelerator information detection unit 116 detects an input (accelerator opening) to the accelerator pedal by the driver, and outputs the detected value to the ECU 130 as accelerator information (accelerator command value).
  • the brake information detection unit 117 detects an input to the brake pedal by the driver as a brake pedal force by the brake pedal force sensor 220, and outputs the detected value to the ECU 130 as brake information (brake command value).
  • the ECU 130 outputs vehicle information including the steering angle command signal to the control unit 150b of the second steering device 150.
  • a method of detecting the brake pedal force in addition to a method of detecting the brake pedal depression amount with a brake pedal depression amount sensor, a method of detecting the force pushing the master cylinder of the brake with a strain gauge or a piezoelectric element, a hydraulic pressure for operating the brake There is a method of detecting the pressure of the path with a brake hydraulic pressure sensor.
  • the ECU 130 determines command values such as an accelerator command value and a brake command value based on the vehicle information and outputs them to the related in-vehicle system.
  • the control unit 150b of the second steering device 150 receives vehicle speed information, steering angle information, vehicle height information, actual yaw rate information, actual lateral acceleration information, accelerator information (accelerator command value), and brake information (brake command value) from the ECU 130. ), And based on the acquired vehicle information, the auxiliary steering control unit 151 controls the actuator drive control unit 31R for the right wheel and the actuator drive control unit 31L for the left wheel,
  • the right wheel hub unit 1 ⁇ / b> R and the left wheel hub unit 1 ⁇ / b> L are each driven with a motor 26, and the left and right wheels can be steered independently.
  • control unit 150b the relationship between each information such as the steering angle information as the vehicle information and the command value for driving the motor 26 is determined as a control rule using, for example, a map or an arithmetic expression. Control using rules.
  • the control unit 150b is provided as a dedicated ECU, for example, but may be provided as a part of the main ECU 130.
  • the auxiliary steering control unit 151 in the control unit 150b includes toe angle control means 37A.
  • the toe angle control means 37A controls the steering actuator 5 (FIG. 2) so that the left and right wheels 9, 9 (FIG. 1), which are front wheels, have a predetermined toe angle in accordance with the brake depression force. That is, when the driver depresses the brake and decelerates, the toe angle control means 37A adjusts the toe angle of the left and right wheels 9, 9 (FIG. 1) as front wheels, thereby increasing the resistance between the tire and the road surface. To reduce the braking distance and improve the safety of the vehicle.
  • the toe angle control means 37A causes the driver's brake pedal force to be a constant toe angle Xdeg from “0” to a predetermined brake pedal force FL, and then the brake pedal force becomes large. Accordingly, the steering actuator 5 (FIG. 2) is controlled so that the toe angles of the left and right wheels 9, 9 (FIG. 1) gradually increase. In this embodiment, the toe angle moves in the toe-in direction as the brake pedal force increases. The state of the left and right wheels 9, 9 displayed by the dotted line in FIG. 1 is the toe-in state. By this control, the vehicle can be decelerated stably without feeling uncomfortable for the driver.
  • the relationship between the brake pedal force and the toe angle shown in FIG. 10 is determined as a control rule using, for example, a map or an arithmetic expression.
  • the toe angle shall not be increased beyond the maximum value B.
  • the maximum value B of the toe angle may be determined in advance based on the related mechanical constraints and vehicle stability under general conditions, or the contact between the tire and the road surface.
  • the state may be detected and determined each time based on the detection result.
  • the driver feels comfortable, shortening the braking distance and stabilizing the vehicle behavior during braking when necessary.
  • An effect can be obtained.
  • the toe angle control means 37A performs the above-described toe angle control in both cases of straight running and turning.
  • the toe angle control means 37A gives an auxiliary braking force for assisting the braking force by the brake 21 (FIG. 3) to the vehicle.
  • the left and right wheels 9 and 9 are selected according to the brake pedal force. Is controlled to move in the toe-in direction, but may be controlled to move in the toe-out direction. For example, in the initial state, when the left and right wheels 9, 9 are slightly in a toe-out state or the toe angle is set to zero degree, the toe angle of the left and right wheels 9, 9 increases in the toe-out direction as the brake pedal force increases.
  • the steering actuator 5 (FIG. 2) is controlled to move. Even in such a control that moves in the toe-out direction, the braking resistance can be shortened by increasing the rotational resistance of each wheel.
  • FIG. 11 is a flowchart showing the process of controlling the toe angle step by step. This will be described with reference to FIGS. 9 and 10 as well.
  • the brake information detection unit 117 receives an input to the brake pedal as a brake pedal force sensor 220. Is detected as a brake depression force (step S2).
  • the toe angle control means 37A determines the toe angle in accordance with the brake depression force (step S3).
  • the control unit 150b calculates the driving amount of each steering actuator (such as a current flowing through the motor 26) (step S4), and drives each steering actuator (step S5).
  • step S6: Yes when the control unit 150b determines that the vehicle speed obtained from the vehicle speed detection unit 111 via the ECU 130 is “0” km / h (step S6: Yes), the present process ends. If it is determined that the vehicle is traveling (step S6: No), the process returns to step S1. The adjustment of the toe angle is repeated until the vehicle stops while the driver continues to depress the brake.
  • the auxiliary steering control unit 151 performs the control shown in FIG. 12 below in addition to the toe angle control (control shown in FIG. 11 and the like) according to the brake pedal force described above.
  • the control shown in FIG. 12 and the control shown in FIG. 11 and the like may be switched according to the driver's switching operation or the vehicle situation, or may be executed in parallel.
  • the auxiliary steering control unit 151 includes a reference lateral acceleration calculation unit 152, a right wheel tire angle calculation unit 153, a left wheel tire angle calculation unit 154, a right wheel road surface friction coefficient calculation unit 155, and a target yaw rate calculation unit 156.
  • the right wheel tire angle calculation unit 153 and the left wheel tire angle calculation unit 154 acquire steering angle information and vehicle height information from the ECU 130 at a predetermined cycle.
  • the right wheel tire angle calculation unit 153 and the left wheel tire angle calculation unit 154 calculate the current angle of the tire that the second steering device 150 (FIG. 9) steers based on the acquired steering angle information and vehicle height information. Then, the calculated tire angle information is output to the reference lateral acceleration calculation unit 152.
  • the standard lateral acceleration calculation unit 152 calculates the standard lateral acceleration based on the vehicle speed information acquired from the ECU 130 and the tire angle information.
  • the reference lateral acceleration calculation unit 152 outputs the calculated reference lateral acceleration as reference lateral acceleration information to the right wheel road surface friction coefficient calculation unit 155 and the left wheel road surface friction coefficient calculation unit 157.
  • FIG. 13 is a diagram showing a map for calculating the road surface friction coefficient, and this map is stored in the right wheel road surface friction coefficient calculation unit 155 and the left wheel road surface friction coefficient calculation unit 157 shown in FIG.
  • the right wheel road surface friction coefficient calculation unit 155 and the left wheel road surface friction coefficient calculation unit 157 calculate road surface friction coefficients based on the actual lateral acceleration information acquired from the ECU 130 and the reference lateral acceleration information input from the reference lateral acceleration calculation unit 152. I do. Specifically, when the reference lateral acceleration information is input from the reference lateral acceleration calculation unit 152, the right wheel road surface friction coefficient calculation unit 155 and the left wheel road surface friction coefficient calculation unit 157 receive the right wheel tire angle calculation unit 153 and the left wheel tire.
  • Tire angle information is acquired from the angle calculation unit 154.
  • the right wheel road surface friction coefficient calculation unit 155 and the left wheel road surface friction coefficient calculation unit 157 calculate the road surface friction coefficient from the actual lateral acceleration / reference lateral acceleration and the tire angle based on the map (FIG. 13).
  • the right wheel road surface friction coefficient calculating unit 155 and the left wheel road surface friction coefficient calculating unit 157 include right wheel road surface friction coefficient information that is the calculated road surface friction coefficient of the right wheel and left wheel road surface friction coefficient information that is the road surface friction coefficient of the left wheel. And output to the target yaw rate correction unit 158.
  • the target yaw rate calculation unit 156 calculates a target yaw rate based on vehicle speed information and steering angle information acquired from the ECU 130 at a predetermined cycle, and outputs the calculated target yaw rate to the target yaw rate correction unit 158 as target yaw rate information.
  • the target yaw rate correction unit 158 receives the target yaw rate calculation unit 156 from the target yaw rate calculation unit 156.
  • the yaw rate information is acquired, and the target yaw rate is corrected according to the road surface friction coefficient represented by the right wheel road surface friction coefficient information and the left wheel road surface friction coefficient information.
  • the target yaw rate correction unit 158 outputs the corrected target yaw rate to the target left and right wheel tire angle calculation unit 159 as corrected yaw rate information.
  • the target left and right wheel tire angle calculation unit 159 When the corrected left and right wheel tire angle calculation unit 159 receives the corrected yaw rate information, the target left and right wheel tire angle calculation unit 159 acquires the actual yaw rate information, the accelerator command value, and the brake command value from the ECU 130, and the right wheel road surface friction coefficient information and the left wheel road surface friction coefficient information. And the target left and right wheel tire angle, which is the target value of the tire angle of the left and right wheels, is calculated. Specifically, the target left and right wheel tire angle calculation unit 159 calculates the target angle of each of the left and right tires based on the following formula (1).
  • the yaw rate of the actual vehicle ⁇ y is represented by the actual yaw rate information
  • X A is the accelerator command value
  • X B is a brake command value
  • mu L is the left wheel road surface coefficient of friction
  • theta tL1 is the target tire angle of the left wheel.
  • the target left and right wheel tire angle calculation unit 159 outputs the calculated target tire angles of the left and right wheels to the right wheel command value calculation unit 160 and the left wheel command value calculation unit 161 as target tire angle information.
  • the right wheel command value calculation unit 160 and the left wheel command value calculation unit 161 represent the current tire angle from the right wheel tire angle calculation unit 153 and the left wheel tire angle calculation unit 154.
  • Tire angle information is acquired, and the target tire angle represented by the target tire angle information is compared with the current tire angle. If there is a deviation as a result of comparing the target tire angle with the current tire angle, right wheel steering indicating the amount by which each of the right wheel hub unit 1R (FIG. 9) and the left wheel hub unit 1L (FIG. 9) is steered. Amount information and left wheel steering amount information are generated.
  • the right wheel command value calculation unit 160 outputs the generated right wheel steering amount information (current command signal) to the right wheel actuator drive control unit 31R, and the left wheel command value calculation unit 161 generates the generated left wheel steering amount information ( Current command signal) is output to the left wheel actuator drive control section 31L.
  • Each actuator drive control unit 31R, 31L includes an inverter. Each actuator drive control unit 31R, 31L controls the current to the motor 26 (FIG. 9) of each steering actuator based on the right wheel steering amount information and the left wheel steering amount information. Specifically, as shown in FIGS. 9 and 12, each actuator drive control unit 31R, 31L receives the right wheel steering amount information and the left wheel steering amount information from the right wheel command value calculation unit 160 and the left wheel command value calculation unit 161. Is input, the position information of each motor 26 indicating the steering angle of the current right wheel hub unit 1R and the left wheel hub unit 1L is acquired, and the motor 26's position information is obtained based on the right wheel steering amount information and the left wheel steering amount information. The target position is determined and the current flowing to each motor 26 is controlled.
  • each actuator drive control unit 31R, 31L outputs a current corresponding to the current command signal input from the auxiliary steering control unit 151 to drive-control the steering actuator 5.
  • the actuator drive controllers 31R and 31L control the power supplied to the coil of the motor 26.
  • the actuator drive control units 31R and 31L constitute, for example, a half bridge circuit using a switch element (not shown), and perform PWM control for determining a motor applied voltage based on an ON-OFF duty ratio of the switch element. Thereby, in addition to steering by the driver's steering wheel operation, the angle of the wheel can be minutely changed.
  • the first steering device 11 steers the wheels 9 and 9 in accordance with the steering amount command output from the steering command device.
  • the steering command device for example, the driver's handle 200 or an automatic steering command device can be applied. Adjustment of the direction of the vehicle 100 by such a steering command device or the like can be performed similarly to a conventional vehicle.
  • the second steering device 150 drives the steering actuator 5 provided in the tire housing 105 to steer the left and right wheels 9 and 9 individually.
  • the toe angle control means 37A controls the steering actuator 5 so that the left and right wheels 9, 9 have a predetermined toe angle according to the brake depression force.
  • the toe angle control means 37A controls the steering actuator 5 so that the toe angle increases as the brake pedal force increases.
  • the following effects are obtained by performing toe angle control according to the brake depression force.
  • the resistance between the tire and the road surface can be increased to assist the braking force.
  • the straight running stability at the time of brake braking can be improved, and the fluctuation of the vehicle can be suppressed.
  • the hub unit with a steering function can be used as an auxiliary to the brake 21 that is operated by normal hydraulic pressure or the like, the size of the normal brake 21 can be set to be compact.
  • the hub unit body 2 including the hub bearing 15 can be freely rotated around the turning axis A within a certain range by driving the steering actuator 5. .
  • steering can be performed independently for each wheel, and the toe angle of the wheel 9 can be arbitrarily changed according to the traveling state of the vehicle 100.
  • the rudder angle difference between the left and right wheels 9, 9 can be changed according to the traveling speed.
  • the steering geometry can be changed during traveling, such as parallel geometry for turning in a high speed region and Ackermann geometry for turning in a low speed region.
  • the wheel angle can be arbitrarily changed during traveling, it is possible to improve the motion performance of the vehicle 100 and travel stably and safely.
  • the steering angle of the left and right steered wheels the turning radius of the vehicle 100 in turning traveling can be reduced and the turning performance can be improved.
  • the auxiliary steering control unit 151 in the control unit 150 b includes a determination unit 33 and an emergency braking state toe angle control unit 36.
  • the toe angle control means 37A is not shown.
  • the determination unit 33 determines whether or not the vehicle is in an emergency braking state (when a sudden brake command is output) from the vehicle speed and braking force (braking force) acquired from the ECU 130.
  • the emergency braking state means that in this vehicle running state, the brake pedal force detected by the brake pedal sensor 117 by the driver's operation of the brake pedal 220 is equal to or greater than a threshold value, and the amount of change in the brake pedal force is equal to or greater than the threshold value.
  • an automatic brake device 220A described later recognizes other vehicles, vehicle surrounding conditions such as obstacles, etc. from sensors such as a camera or millimeter wave radar. This is when the sudden brake command is automatically generated and output when the collision determination is satisfied.
  • the brake command generation means of the ECU 130 controls the normal brake 21 (FIG. 3) to operate.
  • the automatic brake system includes an automatic brake device 220A, the brake command generation means, and a brake 21 (FIG. 3). Whether or not the vehicle is in a running state is determined from the vehicle speed obtained from the vehicle speed detection unit 111 via the ECU 130.
  • Each of the threshold values is a value arbitrarily determined by design or the like, and is determined by obtaining an appropriate threshold value by, for example, testing and / or simulation.
  • the emergency braking state toe angle control means 36 determines that the right and left wheels 9 and 9 are in a toe-in state (left and right wheels indicated by dotted lines in FIG. 1) when the determination means 33 determines that the braking state is emergency. 9 and 9), the steering actuator 5 (FIG. 2) is controlled so that the maximum steering angle or the toe angle corresponding to the vehicle speed is obtained.
  • the emergency braking state toe angle control means 36 performs toe angle control in the emergency braking state in both cases of straight running and turning. This emergency braking state toe angle control means 36 gives the vehicle an auxiliary braking force that assists the braking force by the brake 21 (FIG. 3). Since the left and right wheels 9, 9 (FIG.
  • the left and right wheels 9, 9 (FIG. 1) can obtain stable braking if they are toe-in rather than toe-out, in this embodiment, the left and right wheels 9, 9 (FIG. 1) are toe-in in an emergency braking state. However, you can use toe-out. Even in toe-out, the braking resistance can be shortened by increasing the rotational resistance of each wheel.
  • the emergency braking state toe angle control means 36 has the maximum toe angle B deg and the vehicle speed in the middle and high speed range when the vehicle speed is in the low speed range (VL km / h or less). In (greater than VLkm / h), the toe angle is gradually decreased as the vehicle speed increases. This is because when the toe angle is suddenly changed from the high speed range, the wheels are undesirably locked and the tires slip, which may reduce the braking force. Further, the emergency braking state toe angle control means 36 maximizes the left and right wheels 9 and 9 (FIG. 1) regardless of the vehicle speed when the normal brake 21 (FIG. 3) is determined to be abnormal in the emergency. Control the toe-in angle.
  • the emergency braking state toe angle control means 36 outputs, for example, a brake pedal force by operating the brake pedal 220 or a sudden brake command (referred to as “brake command etc.” together with the brake pedal force) by the automatic brake device 220A.
  • a brake pedal force by operating the brake pedal 220 or a sudden brake command (referred to as “brake command etc.” together with the brake pedal force) by the automatic brake device 220A.
  • brake command etc. a sudden brake command
  • FIG. 16 is a flowchart showing step by step processing for controlling the toe angle. This will be described with reference to FIGS. 14 and 15 as well.
  • the automatic brake device 220A outputs an emergency brake command (rapid brake command) and the emergency brake command is given to the determination means 33 (step S1: Yes) while the vehicle is running, the emergency braking state toe angle control means 36 is provided. Determines whether the normal brake 21 (FIG. 3) is abnormal (step S2).
  • step S2 When it is determined that there is no abnormality in the normal brake 21 (FIG. 3) (step S2: No), the emergency braking state toe angle control means 36 determines the toe angle according to the vehicle speed (step S3), and the normal brake When it is determined that there is an abnormality in 21 (FIG. 3) (step S2: Yes), the emergency braking state toe angle control means 36 keeps the maximum toe angle (X + Bdeg) constant (step S4). Thereafter, the process proceeds to step S7 described later.
  • step S5 When there is no emergency brake command from the automatic brake device 220A (step S1: No), the determination means 33 has the brake pedal force detected by the brake pedal sensor 117 equal to or greater than a threshold value and the amount of change in the brake pedal force equal to or greater than the threshold value (abrupt It is determined whether or not the brake is activated (step S5). If it is determined that the sudden braking is in operation (step S5: Yes), the process proceeds to step S2. If it is determined that it is not during the sudden braking operation (step S5: No), the control unit 150b determines a toe angle according to the brake depression force (step S6). In step S6, the control unit 150b performs control such that the toe angle increases as the brake pedal force increases, for example. Thereafter, the process proceeds to step S7.
  • the control unit 150b calculates the driving conditions of each steering actuator (such as a current flowing through the motor 26) (step S7), and drives each steering actuator (step S8).
  • step S7 calculates the driving conditions of each steering actuator (such as a current flowing through the motor 26)
  • step S8 drives each steering actuator
  • the auxiliary steering control unit 151 performs the control of independently steering the left and right wheels as described with reference to FIG. 12 in addition to the toe angle control in the emergency braking state.
  • the control shown in FIG. 12 and the control shown in FIG. 16 may be switched according to the driver's switching operation or the vehicle situation, or may be executed in parallel.
  • the determination unit 33 determines whether the vehicle is in the emergency braking state from the vehicle speed and the braking force (braking force). Determine whether or not.
  • the emergency braking state toe angle control means 36 controls the steering actuator 5 so that the left and right wheels 9, 9 have the maximum steering angle in the toe-in state, for example. .
  • the rotational resistance of each wheel is increased to shorten the braking distance and improve the vehicle safety, compared to when each wheel is in a straight traveling state (toe angle is zero degrees), for example. be able to.
  • the emergency braking state toe angle control means 36 determines that it is in an emergency braking state, Since the steering actuator 5 is controlled so that the left and right wheels 9 and 9 have the maximum steering angle in the toe-in state, for example, an auxiliary braking force can be applied to the vehicle.
  • the first and second steering systems 11 and the second steering device 150 steer different wheels 9 from each other. This is different from the embodiment. That is, in the steering system 101, the first steering device 11 steers the left and right front wheels 9 and 9 of the vehicle 100, and the second steering device 150 steers the left and right rear wheels 9 and 9 of the vehicle 100. .
  • the mechanism portion 150 a of the second steering device 150 is installed in the rear wheel tire housing 105.
  • the steering system 101 differs from the first and second embodiments in that it includes two second steering devices 150 1 and 150 2. .
  • One second steering device 150 1, as well as the first steering device 11 performs steering of the left and right wheels 9, 9 are front wheels, a second steering device 150 2 on the other are rear left and right The wheels 9, 9 are steered. That is, the second steering device 150 1 on one performs the same operation as the second steering device 150 according to the first and second embodiments, the second steering device 150 2 on the other, the third The same operation as that of the second steering device 150 according to the embodiment is performed.
  • this steering system 101 by providing a plurality of (two in this example) second steering devices 150 1 and 150 2 , it becomes possible to more independently independently steer four wheels, It is possible to improve the running stability of the vehicle 100 and reduce the fuel consumption.
  • the left and right wheels are each provided with a second steering device that can be steered independently, and each wheel is independently driven by a steering actuator.
  • These steering devices may be, for example, steer-by-wire types that are not mechanically coupled to the steering command device.
  • the steering command device is the handle 200.
  • a manual steering command device other than the handle 200 for example, a joystick may be used.
  • the steering command device 200A may be used.
  • This automatic steering command device 200A is a device that recognizes a vehicle surrounding situation from the vehicle surrounding situation detection means 230 and automatically generates a steering command.
  • the vehicle surrounding state detection means 230 is, for example, a sensor such as a camera or a millimeter wave radar.
  • the automatic steering command device 200A recognizes white lines and obstacles on the road, for example, and generates and outputs a steering command.
  • the automatic steering command device 200A may be a part of a device that performs automatic driving of a vehicle or a device that supports steering by manual driving. Even in a vehicle equipped with such a steering command device 200A that automatically generates a steering command, by providing the second steering device 150, operations that cannot be performed by the first steering device 11, such as toe angle control, can be performed. It is also possible to perform main steering in the traveling direction of the vehicle with the first steering device 11 and to correct it with the second steering device 150, and to correct the vehicle direction with respect to the steering amount command. Thus, it is possible to maintain the running stability of the vehicle.
  • the toe angle control means 37A may perform toe angle control according to the brake depression force when the vehicle stops. In this case, for example, when the vehicle stops on an uphill road, the frictional resistance between the tire and the road surface can be increased, and the vehicle can be easily prevented from retreating without using a parking brake or the like.
  • a steering system provided in a vehicle, A first steering device that steers the wheels of the vehicle according to a steering amount command output by the steering command device; A second steering device having a mechanism for individually turning left and right wheels by driving a steering actuator provided in a tire housing of the vehicle, and a control unit for controlling the steering actuator; A vehicle information detection unit that detects vehicle information including vehicle speed and braking force, The control unit includes an emergency braking state toe angle control unit that controls a toe angle with respect to the steering actuator when a sudden brake command is output from the brake command unit.
  • the emergency braking state toe angle control means has the toe angle as a maximum angle.
  • the emergency braking state toe angle control means determines a toe angle according to a vehicle speed.
  • the control unit includes a determination unit that determines whether or not an emergency braking state is obtained from a vehicle speed and a braking force, and the emergency braking state toe
  • the angle control means is a steering system that controls the steering actuator so that a predetermined toe angle is obtained when the determination means determines that the emergency braking state is established.
  • the mechanism portion of the second steering device is A hub unit body having a hub bearing for supporting the wheel; A unit support member provided on a suspension frame part of the suspension device and rotatably supporting the hub unit body about a turning axis extending in the vertical direction; A steering system comprising: the steering actuator that rotates the hub unit body about the turning axis.
  • SYMBOLS 2 ... Hub unit main body, 3 ... Unit support member, 5 ... Steering actuator, 6 ... Knuckle (suspension frame part), 9 ... Wheel, 11 ... First steering device, 12 ... Suspension device, 15 ... Hub bearing, 31R, 31L ... Actuator drive control unit, 37A ... Toe angle control means, 100 ... Vehicle, 101 ... Steering system, 105 ... Tire housing, 110 ... Vehicle information detection unit, 150 ... Second steering device, 150a ... Mechanism unit, 150b ... control unit, 151 ... auxiliary steering control unit, 200 ... handle (steering command device), 200A ... automatic steering command device

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Steering Control In Accordance With Driving Conditions (AREA)
  • Power Steering Mechanism (AREA)

Abstract

L'invention concerne un système de direction pouvant réduire la distance de freinage d'un véhicule pendant le freinage, améliorer la stabilité en ligne droite pendant le freinage, tout en stabilisant le comportement du véhicule pendant le freinage. Un système de direction (101) est pourvu d'un premier dispositif de direction (11), d'un second dispositif de direction (150) qui comprend une unité mécanique (150a) pour diriger individuellement les roues gauche et droite par entraînement d'actionneurs de direction, une unité de commande (150b) pour commander les actionneurs de direction, et une unité de détection d'informations de véhicule (110) qui détecte une force de pédale de frein. L'unité de commande (150b) comprend un moyen de commande d'angle de parallélisme (37A) pour commander les actionneurs de direction de telle sorte que les roues gauche et droite adoptent un angle de parallélisme prescrit en fonction de la force de pédale de frein.
PCT/JP2019/012713 2018-03-27 2019-03-26 Système de direction et véhicule pourvu de celui-ci WO2019189095A1 (fr)

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JP2018-059169 2018-03-27
JP2018-059167 2018-03-27
JP2018059167A JP2019171905A (ja) 2018-03-27 2018-03-27 ステアリングシステムおよびこれを備えた車両
JP2018059169A JP2019171907A (ja) 2018-03-27 2018-03-27 ステアリングシステムおよびこれを備えた車両

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CN113895215A (zh) * 2021-09-29 2022-01-07 酷哇环境技术有限公司 一种全向移动底盘系统

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