JP2011173560A - Camber control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the stability of a vehicle when passing through a crossing while changing the traveling direction. <P>SOLUTION: A camber control device includes: a vehicle body; a plurality of wheels; a camber varying mechanism applying a camber to a wheel; a crossing-passing stable camber determination-processing means determining whether or not a condition for applying the camber for passing through the crossing set in correspondence with the accelerating state of the vehicle is met, when the vehicle passes through the crossing; and a camber application processing means applying the camber to the wheel, when the condition for applying the camber for passing through the crossing is met. When the vehicle recedes from the crossing while accelerating after the vehicle proceeds to the crossing and changes the direction, even if an excessive centrifugal force is generated, the stability of the vehicle is enhanced. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a camber control device.

  2. Description of the Related Art Conventionally, there has been provided a vehicle that can give a negative camber (negative camber) to a rear wheel.

  In this type of vehicle, when the vehicle travels straight, that is, when the vehicle travels straight, it is determined whether or not a preset condition is satisfied. The camber is given to the tire.

  In this case, since the canvas last can be generated in each of the rear wheels in a direction facing each other, the stability of the vehicle during high-speed traveling can be increased (see, for example, Patent Document 1).

JP-A-60-193781

  However, in the conventional vehicle, when the driver operates the steering wheel to turn the vehicle, that is, when the vehicle turns, a negative camber is not applied to each rear wheel.

  Therefore, for example, when the vehicle enters the intersection, changes the direction of travel, and then exits the intersection while accelerating, such as when changing the direction of travel and passing through the intersection, if excessive centrifugal force occurs, The stability of the vehicle will be lowered.

  It is an object of the present invention to provide a camber control device that solves the problems of the conventional vehicle and can increase the stability of the vehicle when changing the traveling direction and passing through an intersection.

  For this purpose, in the camber control device of the present invention, the vehicle body, a plurality of wheels rotatably arranged with respect to the body, and a predetermined wheel among the wheels are arranged. A camber variable mechanism for imparting camber and an intersection passing stable camber that determines whether or not a camber imparting condition for passing an intersection set corresponding to the acceleration state of the vehicle is satisfied when the vehicle passes the intersection. A camber that applies a camber to the predetermined wheel by operating the camber variable mechanism when it is determined by the determination processing means and the intersection passing stable camber determination processing means that the camber providing condition for passing the intersection is satisfied. Providing processing means.

  According to the present invention, in the camber control device, a vehicle body, a plurality of wheels disposed rotatably with respect to the body, and a predetermined wheel among the wheels are provided. A camber variable mechanism for imparting camber and an intersection passing stable camber that determines whether or not a camber imparting condition for passing an intersection set corresponding to the acceleration state of the vehicle is satisfied when the vehicle passes the intersection. A camber that applies a camber to the predetermined wheel by operating the camber variable mechanism when it is determined by the determination processing means and the intersection passing stable camber determination processing means that the camber providing condition for passing the intersection is satisfied. Providing processing means.

  In this case, when the vehicle passes through the intersection, it is determined whether or not the camber provision condition for passing the intersection set corresponding to the acceleration state of the vehicle is satisfied, and the camber provision condition for passing the intersection is satisfied In addition, since the camber is given to the predetermined wheel, even if excessive centrifugal force is generated when the vehicle enters the intersection, changes the traveling direction, and then exits the intersection while accelerating, The stability of can be increased.

It is a control block diagram of the vehicle in the embodiment of the present invention. It is a conceptual diagram of the vehicle in embodiment of this invention. It is sectional drawing of the wheel in embodiment of this invention. It is a 1st main flowchart which shows operation | movement of the control part in embodiment of this invention. It is a 2nd main flowchart which shows the operation | movement of the control part in embodiment of this invention. It is a figure which shows the subroutine of the steering stability camber necessity determination process in embodiment of this invention. It is a figure which shows the subroutine of the straight travel stable camber necessity determination process in embodiment of this invention. It is a figure which shows the subroutine of the grounding load determination process in embodiment of this invention. It is a figure which shows the subroutine of an intersection passage stable camber determination process in embodiment of this invention. It is a figure which shows the subroutine of the intersection exit determination process in embodiment of this invention. It is a figure for demonstrating the state of the vehicle at the time of passing the intersection in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 is a conceptual diagram of the vehicle in the embodiment of the present invention.

  In the figure, 11 is a body that is a vehicle body, 12 is an engine as a drive source, WLF, WRF, WLB, and WRB are arranged on the left front, right front, and left rear that are rotatably arranged with respect to the body 11. And the right rear wheel. The wheels WLF and WRF constitute a front wheel, and the wheels WLB and WRB constitute a rear wheel.

  In the present embodiment, the vehicle has a rear-wheel drive structure, and the wheels WLB and WRB function as drive wheels. The engine 12 and the wheels WLB and WRB are connected to each other via a propeller shaft 17 as a first transmission shaft, a differential 18 and a drive shaft 46 as a second transmission shaft, thereby driving the engine 12. The generated rotation is transmitted to the wheels WLB and WRB. In the present embodiment, the vehicle has a rear-wheel drive system structure, but may have a front-wheel drive system structure or a four-wheel drive system structure. . Further, an engine, a generator, and a motor can be arranged as a drive source to configure a hybrid vehicle, or a motor can be arranged as a drive source to configure an electric vehicle.

  Further, 13 is a steering wheel as an operation unit for steering the vehicle and as a steering member, 14 is an accelerator pedal as an operation unit for accelerating the vehicle and as an acceleration operation member, and 15 A brake pedal as an operation unit for braking the vehicle and as a braking operation member.

  Reference numerals 31 and 32 are disposed between the body 11 and the wheels WLB and WRB, respectively, as camber variable mechanisms for applying camber to the wheels WLB and WRB and releasing the camber. Actuator. In the present embodiment, the actuators 31 and 32 are arranged between the body 11 and the wheels WLB and WRB, respectively. However, the actuator is arranged between the body 11 and the wheels WLF and WRF. An actuator can be disposed between the body 11 and the wheels WLF, WRF, WLB, WRB.

  By the way, the wheels WLF, WRF, WLB, and WRB include a wheel (not shown) formed of an aluminum alloy or the like, and a tire 36 that is fitted to the outer periphery of the wheel. As the tire 36, a low rolling resistance tire in which the rolling resistance generated by deformation of the tread of the tire 36 is reduced by reducing the loss tangent over the entire width direction of the tire 36 is used. In this case, since the rolling resistance of the tire 36 is reduced, the fuel consumption can be improved.

  In the present embodiment, the width of the tire 36 is made smaller than that of a normal tire in order to reduce the rolling resistance. However, the tread pattern, which is a tread groove pattern, is shaped so as to reduce the rolling resistance. Alternatively, the material of at least the tread portion can be made to have a low rolling resistance.

  The loss tangent represents the degree of energy absorption when the tread is deformed, and can be represented by the ratio of the loss shear elastic modulus to the storage shear modulus. The smaller the loss tangent, the less energy is absorbed by the tread, so the rolling resistance generated in the tire 36 is reduced and the wear generated in the tire 36 is reduced. On the other hand, the greater the loss tangent, the more energy is absorbed by the tread, so the rolling resistance generated in the tire 36 increases and the wear generated in the tire 36 increases.

  Next, the actuators 31 and 32 for giving camber to the wheels WLB and WRB and releasing the camber will be described. In this case, since the structures of the actuators 31 and 32 are the same, only the wheel WLB and the actuator 31 will be described.

  FIG. 3 is a sectional view of the wheel in the embodiment of the present invention.

  In the figure, WLB is a wheel, 21 is a wheel, 31 is an actuator, and 36 is a tire.

  The actuator 31 includes a motor 41 as a drive unit for camber control fixed to a knuckle (not shown) as a base member, a movable plate 43 as a movable member arranged to be swingable with respect to the knuckle, the motor A crank mechanism 45 serving as a motion direction conversion mechanism that converts the rotational motion of 41 into a swing motion of the movable plate 43, the drive shaft 46 that transmits the rotation of the engine 12 (FIG. 2) to the wheel 21, and the like. The wheel 21 is rotatably supported with respect to the movable plate 43 and is connected to the drive shaft 46.

  The crank mechanism 45 is rotatably arranged with respect to the worm gear 51 as the first conversion element attached to the output shaft of the motor 41 and the knuckle, and meshes with the worm gear 51. A worm wheel 52 as a second conversion element, and an arm 53 as a third conversion element for connecting the worm wheel 52 and the movable plate 43 and as a connection element. The arm 53 is connected to the worm wheel 52 through a first connecting portion at a position eccentric from the rotation axis of the worm wheel 52 at one end, and is connected to the second end at the upper end of the movable plate 43 at the other end. It is connected to the movable plate 43 through the connecting portion. In this case, the movable plate 43 constitutes a fourth conversion element.

  The worm gear 51 and the worm wheel 52 convert the direction of the axis of the rotational motion of the worm gear 51 and the worm wheel 52, and the worm wheel 52 and the arm 53 convert the rotational motion of the worm wheel 52 into the straight motion of the arm 53. The straight motion of the arm 53 is converted into the swing motion of the movable plate 43 by the arm 53 and the movable plate 43.

  Therefore, when the motor 41 is driven, the worm gear 51 and the worm wheel 52 are rotated, the arm 53 is advanced and retracted, and the movable plate 43 is swung. As a result, a camber having an angle equal to the angle at which the movable plate 43 is tilted with respect to the vertical direction is given to the wheel WLB.

  Next, the vehicle control apparatus having the above-described configuration will be described.

  FIG. 1 is a control block diagram of a vehicle in an embodiment of the present invention.

  In the figure, 16 is a control unit constituting a computer, 60 is a navigation device mounted on a vehicle, 61 is a ROM as a first storage unit, 62 is a RAM as a second storage unit, and 63 is a vehicle speed v. A vehicle speed sensor 64 serving as a vehicle speed detecting unit, and 64, a steering amount for detecting the steering angle γ as a steering amount representing the amount of operation of the steering wheel 13 (FIG. 2) by the driver as an operator and as a steering angle. A steering sensor as a detection unit and a steering operation amount detection unit, 65 a yaw rate sensor as a yaw rate detection unit for detecting the yaw rate η of the vehicle, and 66 a first detection of lateral acceleration ζ as a first acceleration A lateral acceleration sensor 67 as an acceleration detection unit, and 67 a second acceleration detection unit for detecting longitudinal acceleration as a second acceleration A longitudinal acceleration sensor, 68 is a camber sensor as a camber detection unit for detecting camber θ applied to the wheels WLB and WRB, 70 is a display unit having a display screen (not shown), and 71 is a driver of the accelerator pedal 14 by the driver. An accelerator sensor serving as an acceleration operation amount detection unit that detects a depression amount (accelerator opening degree) that represents an operation amount, 72 is a braking operation amount that detects a depression amount (brake stroke) that represents an operation amount of the brake pedal 15 by the driver. A brake sensor as a detection unit, 73 is a suspension stroke sensor as a suspension detection unit for detecting a stroke of a suspension device (not shown) of the wheels WLB and WRB, and 75 is a load as a load detection unit for detecting a load applied to the wheels WLB and WRB. The sensor 76 is a tire crush detecting a crush allowance representing the deformation amount of the tire 36. It is a proxy sensor. A camber control device is constituted by the body 11, the actuators 31 and 32, the control unit 16, and the like.

  The suspension stroke sensor 73 is composed of a height sensor, a magnetic sensor, and the like, and the load sensor 75 is composed of a load cell (strain sensor) disposed in the suspension device.

  The navigation device 60 includes a control unit, an operation unit, a liquid crystal panel as a display unit, a GPS sensor as a current location detection unit that detects the current location (coordinates) of the vehicle as first navigation information, an information recording unit, and the like. The control unit searches for a route from the departure point to the destination based on the map data as the second navigation information recorded in the information recording unit, or guides the searched route, that is, the searched route. To do.

  By the way, in the present embodiment, as described above, the rolling resistance of the tire 36 is reduced. However, when the rolling resistance of the tire 36 is small, the rigidity of the tire 36 is reduced and the road surface by the tire 36 is gripped ( The gripping force, that is, the gripping force is reduced. Therefore, in the present embodiment, even when the rigidity of the tire 36 is low and the grip force is small, the stability when the vehicle travels straight (hereinafter referred to as “running stability”) can be increased. It is determined whether or not a predetermined camber provision condition for straight running is satisfied, and a predetermined turning stability of the vehicle (hereinafter referred to as “turning stability”) can be increased. It is determined whether or not a camber application condition for turning is satisfied, and when each of the camber application conditions is satisfied, the actuators 31 and 32 are operated, and a predetermined negative camber θ is applied to the wheels WLB and WRB. It has become so.

The wheels WLB and WRB are provided with a camber having a predetermined angle defined by the vehicle specification, that is, a reference camber α, as necessary in an initial state in which the actuators 31 and 32 are not activated. Is done. Therefore, in the present embodiment, as described above, when the camber grant condition is satisfied, a predetermined camber is added to the reference camber α, and the camber θ is
−5 [°] ≦ θ <0 [°]
To be. When the reference camber α takes a negative value, the predetermined camber is added to the reference camber α, and the absolute value of the camber θ is increased.

  Next, the operation of the control unit 16 for applying the camber θ to the wheels WLB and WRB and releasing the camber θ will be described.

  FIG. 4 is a first main flowchart showing the operation of the control unit in the embodiment of the present invention, FIG. 5 is a second main flowchart showing the operation of the control unit in the embodiment of the present invention, and FIG. FIG. 7 is a diagram illustrating a subroutine for determining whether a steering stability camber is necessary in the embodiment, FIG. 7 is a diagram illustrating a subroutine for determining whether a straight-line stability camber is necessary in the embodiment of the present invention, and FIG. FIG. 9 is a diagram illustrating a subroutine for ground load determination processing, FIG. 9 is a diagram illustrating a subroutine for intersection passage stable camber determination processing in the embodiment of the present invention, and FIG. 10 is a subroutine for intersection exit determination processing in the embodiment of the present invention. FIGS. 11A and 11B are diagrams for explaining the state of the vehicle when passing the intersection in the embodiment of the present invention.

  First, a determination information acquisition processing unit (not shown) of the control unit 16 performs a determination information acquisition process to give camber θ to the wheels WLB and WRB and to cancel camber θ to the wheels WLB and WRB. Therefore, the determination information necessary for this purpose, the vehicle state representing the state of the vehicle, and the operation state representing the state of operation of each operation unit by the driver are acquired (steps S1 and S2).

  For this purpose, the determination information acquisition processing means includes the vehicle speed sensor 63, the yaw rate sensor 65, the lateral acceleration sensor 66, the longitudinal acceleration sensor 67, the camber sensor 68, the suspension stroke sensor 73, the load sensor 75, the tire collapse allowance sensor 76, and the like. The sensor output as detection information of each detection unit (sensor) and the navigation information sent from the navigation device 60 are read, and the vehicle speed v, yaw rate η, lateral acceleration ζ, longitudinal acceleration, camber θ, Stroke, load, collapse allowance of tire 36, current location, intersection data, etc. are acquired. The intersection data is included in the map data in the navigation information, and includes an approach road, an exit road, the structure of the intersection, etc. in addition to the position and size of each intersection.

  The determination information acquisition processing means calculates an acceleration or deceleration that represents the rate of change (differentiation) of the vehicle speed v, calculates a yaw rate change rate that represents the rate of change of the yaw rate η, or the lateral acceleration ζ. By calculating a lateral acceleration change rate representing the rate of change of the vehicle, or calculating a roll angle based on the suspension stroke, the vehicle state is determined as acceleration, deceleration, yaw rate change rate, lateral acceleration change rate, roll angle. Etc. can also be acquired.

  Next, the determination information acquisition processing means reads sensor output as detection information of each detection unit (sensor) such as the steering sensor 64, the accelerator sensor 71, the brake sensor 72, and the steering angle γ, The amount of depression of the accelerator pedal 14 and the amount of depression of the brake pedal 15 are acquired.

  The determination information acquisition processing means calculates a steering angular velocity that represents the rate of change of the steering angle γ, a steering angular acceleration that represents the rate of change of the steering angular velocity, or a depression that represents the rate of change of the depression amount of the accelerator pedal 14. By calculating the stepping acceleration that represents the change rate of the speed and the stepping speed, or the stepping speed that represents the changing rate of the stepping amount of the brake pedal 15 and the stepping acceleration that represents the changing rate of the stepping speed. As the operation state, the steering angular velocity, the steering angular acceleration, the depression speed and the depression acceleration of the accelerator pedal 14, the depression speed and the depression acceleration of the brake pedal 15, and the like can be acquired.

  Furthermore, instead of the steering sensor 64, a steering angle sensor as a steering amount detection unit may be provided to detect the steering angles of the wheels WLF and WRF as the steering amount. In that case, the determination information acquisition processing means reads the sensor output as detection information of the steering angle sensor, and acquires the steering angle as the operation state. The determination information acquisition processing unit acquires the steering angular speed and the steering angular acceleration as the operation state by calculating the steering angular speed that represents the rate of change of the steering angle and the steering angular acceleration that represents the rate of change of the steering angular speed. You can also.

  Subsequently, the steering stability camber necessity determination processing unit as the first camber provision condition establishment determination processing unit (not shown) of the control unit 16 performs the steering stability camber necessity determination processing as the first camber provision condition establishment determination processing. In this embodiment, when turning the vehicle, it is determined whether or not the camber provision condition for turning is satisfied based on the vehicle state and the operation state in the present embodiment. Steps S3 and S4).

  For this purpose, the steering stability camber necessity determination processing means reads the steering angle γ, the lateral acceleration ζ and the yaw rate η, and determines whether the steering angle γ is equal to or greater than a threshold value γf. Is satisfied, whether the yaw rate η is greater than or equal to the threshold ηf, whether the second application condition is satisfied, and whether the lateral acceleration ζ is greater than or equal to the threshold ζf, the third application condition is satisfied (Steps S3-1 to S3-3).

  In this case, when any one of the first to third provision conditions is satisfied, the steering stability camber necessity determination processing unit determines that the camber provision condition for turning is satisfied (step) S3-4).

  In the present embodiment, when any one of the first to third provision conditions is satisfied, it is determined that the turning camber provision condition is satisfied. However, when two or more of the first to third provision conditions are satisfied, it can be determined that the turning camber provision condition is satisfied.

  In addition to the first to third application conditions, it is determined whether the fourth application condition is satisfied based on whether the steering angular velocity is equal to or higher than the threshold value, and whether the yaw rate change speed is higher than the threshold value. It can also be determined whether the fifth application condition is satisfied, or whether the sixth application condition is satisfied based on whether the lateral acceleration change speed is equal to or greater than a threshold value. In that case, when any one of the first to sixth grant conditions is satisfied, it is determined that the turning camber grant condition is satisfied, or among the first to sixth grant conditions. It can be determined that the camber granting condition for turning is met if at least two granting conditions are established. In this case, since the steering angular velocity is the steering angle γ, the lateral acceleration change rate is the lateral acceleration ζ, and the yaw rate change rate is the change rate of the yaw rate η, the steering angle γ and the lateral acceleration ζ when the turning of the vehicle is started. And the change in yaw rate η is markedly represented. Therefore, since it is possible to quickly determine whether or not the camber provision condition for turning is satisfied, it is possible to accurately impart the camber θ to the wheels WLB and WRB.

When the camber application condition for turning is satisfied, a camber application state determination processing unit (not shown) of the control unit 16 performs a camber application state determination process, reads the camber θp detected by the camber sensor 68, and θp is
-5 [°] ≦ θp <0 [°]
Whether the camber θ is applied to the wheels WLB and WRB is determined based on whether or not (step S5).

  When the camber θ is given to the wheels WLB and WRB, the control unit 16 finishes the process, and when the camber θ is not given to the wheels WLB and WRB, the control unit 16 shows a first camber control processing unit (not shown). The camber providing process means performs a camber providing process as the first camber control process, operates the actuators 31 and 32, and applies the camber θ to the wheels WLB and WRB (step S6).

  Therefore, when the vehicle turns, a centrifugal force is generated in the vehicle, but the wheel on the non-turning center side, that is, the wheel on the outer peripheral side (the wheel WRB is used when the vehicle is turned leftward, and the vehicle is turned rightward. Is the wheel WLB.) When the vehicle is turned to the right, the wheel load is the wheel WRB. .)), The canvas last generated in the tire 36 of the outer peripheral wheel becomes larger than the canvas last generated in the tire 36 of the inner peripheral wheel. As a result, centripetal force can be generated in the vehicle, so that turning stability can be increased.

  On the other hand, in the steering stability camber necessity determination process, if the turning camber provision condition is not satisfied, the straight traveling stable camber necessity determination processing means as the second camber provision condition establishment determination processing means (not shown) of the control unit 16 is performed. In addition, at least one of the vehicle state and the operation state during the straight traveling of the vehicle as the second camber provision condition establishment determination process is performed, and in the present embodiment, the vehicle state and Based on the operation state, it is determined whether or not a camber provision condition for straight traveling is satisfied (steps S7 and S8).

  For this purpose, the straight traveling stability camber necessity determination processing means reads the vehicle speed v and, based on a predetermined time immediately before reading the vehicle speed v, in the present embodiment, the vehicle speed v during the past X [seconds]. The calculated value, in the present embodiment, calculates the average vehicle speed av, reads the steering angle γ, and for a predetermined time immediately before reading the steering angle γ, in the present embodiment, during the past Y [seconds] The steering amount calculation value based on the steering angle γ, in this embodiment, the average steering angle aγ is calculated, the average vehicle speed av during the past X [seconds] is equal to or greater than the threshold value vth1, and the past Y [seconds]. It is determined whether the average steering angle aγ is smaller than the threshold value γth1 (step S7-1). When the average vehicle speed av during the past X [seconds] is equal to or greater than the threshold value vth1 and the average steering angle aγ during the past Y [seconds] is smaller than the threshold value γth1, the straight traveling stability camber necessity determination processing means It is determined that the camber granting condition is satisfied (step S7-2). The threshold value γth1 is set smaller than the threshold value γf.

When the camber provision condition for the straight traveling is satisfied, the camber provision state determination processing unit reads the camber θp, and the camber θp
-5 [°] ≦ θp <0 [°]
Whether or not the camber θ is given to the wheels WLB and WRB is determined (step S9).

  When the camber θ is not applied to the wheels WLB and WRB, the camber applying processing unit operates the actuators 31 and 32 to apply the camber θ to the wheels WLB and WRB (step S10).

  Therefore, when the vehicle travels straight, as the camber θ is applied to the wheels WLB and WRB, the canvas last is generated in the tires 36 of the wheels WLB and WRB in opposite directions. When an external force is applied, a large canvas last is generated in the tire 36 of the wheel on the side opposite to the side where the external force is applied, and the canvas last is applied to the vehicle as a restoring force. As a result, traveling stability can be increased.

  By the way, if uneven wear occurs in the tire 36 of each wheel as the vehicle is driven with the camber θ applied to the wheels WLB and WRB, the life of the tire 36 is shortened. In this embodiment, a predetermined camber release condition is established in order to suppress the occurrence of uneven wear in each tire 36 as the vehicle is driven with the camber θ applied to the wheels WLB and WRB. When the camber release condition is satisfied, the actuators 31 and 32 are operated, the camber θ is no longer applied to the wheels WLB and WRB, and the wheels WLB and WRB are placed in the initial state. .

  For this purpose, a ground load determination processing unit as a camber release determination processing unit (not shown) of the control unit 16 performs a ground load determination process as a camber release determination process to determine whether the camber release condition is satisfied (step). S11, S12).

That is, the ground load determination processing means uses the tire collapse allowance, the suspension stroke, the longitudinal acceleration, the yaw rate η, the roll angle, the load, the brake stroke, the accelerator opening, the steering as a ground load index representing the ground load applied to the tire 36. The angle γ, the steering angular velocity, the steering angular acceleration, etc. are read, and it is determined whether or not each ground load index is equal to or greater than the respective threshold (steps S11-1 to S11-11), and any one of the ground load indices is obtained. In the present embodiment, it is determined that the ground load causes uneven wear in the tire 36 at least when the tire collapse allowance is equal to or greater than a threshold, and it is determined that the camber release condition is satisfied (step S11). -12). When the steering angle γ threshold in the contact load determination process is γth2, the relationship between the threshold γf and the thresholds γth1 and γth2 is
γth2>γ1> γth1
To be.

  When the camber release condition is satisfied in the ground load determination process, the camber release processing unit as the second camber control processing unit (not shown) of the control unit 16 performs the camber release process and operates the actuators 31 and 32. Thus, the camber θ is no longer applied to the wheels WLB and WRB (step S13).

  On the other hand, when the camber provision condition for turning is not satisfied in the steering stability camber necessity determination process, and the camber provision condition for straight traveling is not satisfied in the straight travel stability camber necessity determination process, When the vehicle enters the intersection and changes direction of travel after exiting the intersection while accelerating, as in the case of passing through the intersection, the stability of the vehicle may be lowered.

  For example, as shown in FIG. 11, when the vehicle is turned left at an intersection cr, the driver enters 90 [°] in order to make the vehicle enter the intersection cr from the road r1 and exit from the intersection cr to the road r2. It is necessary to turn at a turning angle. In this case, in the first half of the turn, the driver starts turning by turning the steering wheel 13, gradually increases the steering angle γ, and when the steering angles of the wheels WLF and WRF reach predetermined values, the steering wheel 13 Stop rotating. Thereafter, the driver turns the steering angle until the vehicle makes a half turn at the intersection cr with the turning radius corresponding to the rudder angle, that is, until the vehicle turns 45 [°] which is half the turning angle. Maintain γ.

  When the vehicle turns halfway within the intersection cr, the driver rotates the steering wheel 13 in the opposite direction to gradually reduce the steering angle γ in the second half of the turn, and the steering angles of the wheels WLF and WRF are 0 [°]. Then, the rotation of the steering wheel 13 is stopped. Accordingly, the vehicle can be withdrawn from the intersection cr with the steering angle maintained at 0 [°].

  By the way, when turning the vehicle to the left at the intersection cr, the driver usually decelerates the vehicle and enters the intersection cr, and when the vehicle turns halfway at a low speed within the intersection cr, the vehicle approaches the exit of the intersection cr. It is determined that the vehicle is moving, and the vehicle is made to leave the intersection cr while accelerating.

  At this time, if the other half of the vehicle is turned at a vehicle speed equal to or higher than the appropriate vehicle speed corresponding to the turning radius as the vehicle accelerates, excessive centrifugal force may be generated and the stability of the vehicle may be lowered. is there.

  Therefore, when the straight-running stable camber necessity determination process ends, the intersection passing stable camber determination processing means as the third camber provision condition establishment determination processing means (not shown) of the control unit 16 performs the third camber provision condition establishment determination process. When the vehicle passes through the intersection cr, when the vehicle passes through the intersection cr, the vehicle state and the operation state, in this embodiment, the vehicle state and the operation state are determined based on the vehicle state and the operation state. It is determined whether or not a camber provision condition for passing the intersection set in correspondence with the acceleration state is established (steps S14 and S15).

  For this purpose, the intersection exit determination processing means of the intersection passage stable camber determination processing means performs an intersection exit determination process and determines whether or not the vehicle has reached the exit of the intersection cr (steps S14-1 and 14-2). That is, the intersection exit determination processing means reads the current location, steering angle γ, yaw rate η and lateral acceleration ζ, reads the intersection data, and based on the intersection data, the intersection after the vehicle makes a half turn within the intersection cr The area in cr is calculated with coordinates. Subsequently, the intersection exit determination processing means determines whether the first exit determination condition is satisfied depending on whether the current location has entered the area, whether the steering angle γ is reversed (whether the sign is reversed) ) Whether the second exit determination condition is satisfied, whether the yaw rate η is reversed (whether the sign is reversed or whether the zero point is passed), and whether the third exit determination condition is satisfied Whether or not the fourth exit determination condition is satisfied is determined based on whether the lateral acceleration ζ is inverted (whether the sign is reversed or whether the zero point is passed) (step S14-1-1). ~ S14-1-4).

  When any one of the first to fourth exit determination conditions is satisfied, the intersection exit determination processing unit determines that the vehicle has reached the exit of the intersection cr (step S14-1). -5).

  In the present embodiment, it is determined that the vehicle has reached the exit of the intersection cr when any one of the first to fourth exit determination conditions is satisfied. However, when at least one of the first to fourth exit determination conditions is satisfied, it can be determined that the vehicle has reached the exit of the intersection cr.

  Then, when the vehicle reaches the exit of the intersection cr, the intersection exit camber provision condition determination processing means of the intersection passage stable camber determination processing means performs the intersection exit camber provision condition determination processing, and the vehicle speed v, the steering angle γ, the yaw rate η And the lateral acceleration ζ are read, whether the first exit camber provision condition is satisfied depending on whether the vehicle speed v is equal to or higher than the threshold value vs, and whether the second exit camber is determined depending on whether the steering angle γ is equal to or greater than the threshold value γs. Whether the condition is satisfied, whether the yaw rate η is greater than or equal to the threshold ηs, whether the third exit camber provision condition is satisfied, whether the lateral acceleration ζ is greater than or equal to the threshold ζs, and the fourth exit camber It is determined whether the grant condition is satisfied (steps S14-3 to S14-6).

The threshold values γf, γs, γth1, and γth2 are related as follows:
γth2>γf>γs> γth1
To be.

  In this case, when any one of the first to fourth exit camber grant conditions is satisfied, the intersection exit camber grant condition determination processing unit satisfies the intersection pass camber grant condition. Is determined (step S14-7).

  In this embodiment, when any one of the first to fourth exit camber grant conditions is met, it is determined that the camber grant condition for passing the intersection is met. However, when two or more exit camber granting conditions among the first to fourth exit camber granting conditions are met, it is determined that the intersection passing camber granting condition is met. It can also be done.

When the camber provision condition for passing the intersection is satisfied, the camber provision state determination processing unit reads the camber θp detected by the camber sensor 68, and the camber θp is
-5 [°] ≦ θp <0 [°]
Whether or not camber θ is applied to the wheels WLB and WRB is determined based on whether or not (step S16).

  When the camber θ is applied to the wheels WLB and WRB, the ground load determination processing means determines whether the camber release condition is satisfied as described above (steps S11 and S12), and the camber release condition. When is established, the camber release processing means operates the actuators 31 and 32 to release the camber θ applied to the wheels WLB and WRB (step S13).

  On the other hand, when the camber θ is not applied to the wheels WLB and WRB, the camber applying processing unit operates the actuators 31 and 32 to apply the camber θ to the wheels WLB and WRB (step S17).

In the intersection passage stable camber determination processing, when the camber provision condition for intersection passage is not satisfied, the camber provision state determination processing means reads the camber θp, and the camber θp is
-5 [°] ≦ θp <0 [°]
It is determined whether or not the camber θ is given to the wheels WLB and WRB (step S18).

  When the camber θ is applied to the wheels WLB and WRB, the camber release processing means starts counting by a timer (not shown) as a timing processing unit built in the control unit 16 and starts timing. When a predetermined time elapses (step S19), the actuators 31 and 32 are operated to release the camber θ from the wheels WLB and WRB (step S20).

  Thus, in this embodiment, after the vehicle enters the intersection cr and changes the traveling direction, the vehicle approaches the exit of the intersection cr, and the driver tries to leave the intersection while accelerating the vehicle. Even when the camber application condition for turning is not satisfied, if the camber application condition for passing the intersection is satisfied, camber θ is applied to the wheels WLB and WRB. The generated canvas last becomes larger than the canvas last generated in the tire 36 of the inner peripheral wheel. Accordingly, since the vehicle can generate centripetal force, the vehicle enters the intersection cr and changes the traveling direction, and then accelerates the intersection as if the vehicle changes the traveling direction and passes the intersection cr. Even when excessive centrifugal force is generated when exiting cr, the stability of the vehicle can be increased.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

11 Body 16 Control unit 31, 32 Actuator WLF, WRF, WLB, WRB Wheel

Claims (10)

The body of the vehicle,
A plurality of wheels arranged rotatably with respect to the body;
A camber variable mechanism that is disposed on a predetermined wheel of the wheels and that imparts camber to the wheel;
An intersection passage stable camber determination processing means for determining whether or not an intersection passing camber provision condition set corresponding to the acceleration state of the vehicle is satisfied when the vehicle passes through the intersection;
A camber applying processing means for operating the camber variable mechanism to apply camber to the predetermined wheel when it is determined by the intersection passing stable camber determining processing means that the camber applying condition for passing the intersection is satisfied; A camber control device comprising:   The intersection passage stable camber determination processing means is an intersection exit determination processing means for determining whether or not the vehicle has reached an intersection exit, and the intersection exit determination processing means, when it is determined that the vehicle has reached an intersection exit. The camber control device according to claim 1, further comprising: an intersection exit camber provision condition determination processing unit configured to determine whether or not a camber provision condition for passing the intersection is satisfied. While having a steering camber necessity determination processing means for determining whether or not a camber provision condition for turning is satisfied when the vehicle turns,
The camber control device according to claim 2, wherein the intersection passing stable camber determination processing unit determines whether or not the intersection passing camber providing condition is satisfied when the turning camber applying condition is not satisfied.   4. The camber according to claim 3, wherein a threshold value for determining whether or not the camber provision condition for passing the intersection is satisfied is smaller than a threshold value for determining whether or not the camber provision condition for turning is satisfied. Control device.   The camber control device according to any one of claims 2 to 4, wherein the intersection exit determination processing unit determines whether or not the vehicle has reached an exit of the intersection based on at least one of a vehicle state and an operation state. .   The intersection exit determination processing means determines whether the vehicle is in an intersection when at least one of exit determination conditions such as whether the steering angle is inverted, whether the yaw rate is inverted, and whether the lateral acceleration is inverted is satisfied. The camber control device according to claim 5, wherein the camber control device determines that the exit has been reached.   The camber control device according to any one of claims 2 to 4, wherein the intersection exit determination processing unit determines whether or not the vehicle has reached an exit of the intersection based on navigation information of the navigation device.   The intersection exit camber provision condition determination processing unit determines whether a camber provision condition for passing an intersection is satisfied based on at least one of a vehicle state and an operation state. The camber control device described in 1.   The intersection exit camber grant condition determination processing means is at least one of the exit camber grant conditions of whether the vehicle speed is greater than or equal to a threshold, whether the steering angle is greater than or equal to the threshold, and whether the yaw rate is greater than or equal to the threshold. The camber control device according to claim 8, wherein when one of the two conditions is satisfied, it is determined that a camber provision condition for passing the intersection is satisfied.   The camber control device according to any one of claims 1 to 9, wherein the camber applying processing unit applies camber to a rear wheel.

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