JP2010214989A - Vehicular control device and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular control device and a vehicle capable of exerting excellent turning performance by selectively using cambers of right and left wheels in consideration of a turning state of the vehicle. <P>SOLUTION: When a wheel turns while a brake is applied to the wheel, a second adjustment means adjusts a camber angle of the right or left wheel among the wheels in which the camber angle is adjusted by a first adjustment means according to the turning state detected by a detection means. When the camber angle of the left or right wheel is changed, the balance between a friction resistance from the left wheel and a road surface and the friction resistance from the right wheel and the road surface is relatively changed. Thus, a moment for rotating the vehicle about the center of gravity of the vehicle can be generated according to a change direction of the balance of the friction resistances. Therefore, the moment can be generated according to the turning state, thereby improving the turning state and providing the excellent turning stability. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device and a vehicle, and more particularly, to a vehicle control device and a vehicle that can exhibit excellent turning performance.

  Patent Document 1 discloses a camber that generates a canvas last that opposes the centrifugal force of a vehicle and acts in the direction of the turning center of the vehicle by forcibly tilting the wheel toward the turning center during turning of the vehicle. A suspension device for improving the turning traveling function is disclosed. Specifically, the suspension device described in Patent Document 1 improves the vehicle turning function by using a negative camber on the inner wheel side and a positive camber on the outer wheel side with respect to the turning direction during turning.

JP 60-15213 A

  However, in the technique described in Patent Document 1, the wheels are uniformly tilted toward the turning center without considering what the turning state of the vehicle is when turning, so depending on the turning state of the vehicle. However, there was a problem that the turning performance was not improved.

  The present invention has been made to solve the above-described problems, and provides a vehicle control apparatus and a vehicle that can exhibit excellent turning performance by properly using left and right cambers in consideration of the turning state of the vehicle. The purpose is to do.

  In order to achieve this object, a vehicle control device according to claim 1 includes a vehicle body, wheels arranged on the left and right sides of the vehicle body to support the vehicle body, and a camber angle adjusting device for adjusting a camber angle of the wheel. The wheel includes: a first tread; and a second tread disposed on the inner side or the outer side of the vehicle body with respect to the first tread, wherein the first tread is compared to the second tread. The second tread is used in a vehicle configured to have a characteristic with high grip force and a rolling resistance smaller than that of the first tread, and controls the camber angle adjusting device. A first adjusting means for adjusting a camber angle of the wheel so that a contact ratio of the first tread with respect to a contact of the second tread is increased when the wheel is braked; and detecting a turning state. Out of the wheels whose camber angle is adjusted by the first adjusting means in accordance with the exiting means and the turning state detected by the detecting means during braking of the wheel, the left wheel or the right wheel Second adjusting means for controlling the turning state of the vehicle by adjusting the camber angle of the wheel.

  The vehicle control device according to claim 2 is the vehicle control device according to claim 1, further comprising steering state acquisition means for acquiring a steering state of the wheel, and the detection means is acquired by the steering state acquisition means. And the second adjusting means detects the turning state of the vehicle when the turning state is detected to be an oversteer state by the detecting means. Among the wheels whose camber angle is adjusted by the above, the camber angle of the wheel on the inner ring side with respect to the turning direction is adjusted to the side where the ground contact amount of the second tread is increased.

  The vehicle control device according to claim 3 is the vehicle control device according to claim 1, further comprising steering state acquisition means for acquiring a steering state of the wheel, wherein the detection means is acquired by the steering state acquisition means. Based on the steering state of the vehicle, the turning state of the vehicle is detected, and the second adjusting means detects the turning state by the first adjusting means when the detecting means detects that the turning state is an understeer state. Among the wheels whose camber angles are adjusted, the camber angle of the wheel on the outer wheel side with respect to the turning direction is adjusted to the side where the ground contact amount of the second tread is increased.

  The vehicle control device according to claim 4 is the vehicle control device according to claim 2 or 3, wherein the second adjustment means has an oversteer state or a predetermined level where a turning state of the vehicle exceeds a predetermined level. The camber angle of the left wheel or the right wheel among the wheels whose camber angles are adjusted by the first adjusting means is adjusted only when the detection means detects that the understeer state is exceeding.

  The vehicle according to claim 5 is a vehicle body, wheels arranged on the left and right sides of the vehicle body to support the vehicle body, a camber angle adjusting device for adjusting a camber angle of the wheel, and a control means for controlling the camber angle adjusting device. The wheel includes: a first tread; and a second tread disposed on the inner side or the outer side of the vehicle body with respect to the first tread, wherein the first tread is compared to the second tread. The second tread is configured to have a low rolling resistance compared to the first tread, and the control means is configured to control the second tread when the wheel is braked. It comprises first adjusting means for adjusting the camber angle of the wheel so that the contact ratio of the first tread to the contact of the tread is increased, and detects the turning state of the vehicle. Out of the wheels whose camber angle is adjusted by the first adjusting means according to the turning state detected by the detecting means during braking of the wheels. It further includes second adjusting means for controlling the turning state of the vehicle by adjusting the camber angle of the wheel or the right wheel.

  According to the vehicle control device of the first aspect, the vehicle wheel to be used has the first tread and the second tread, and the grip characteristics (or rolling resistance characteristics) of these treads are different. By controlling the camber angle adjusting device and adjusting the camber angle of the wheel, the ground contact ratio of each tread can be changed, and the grip characteristic (or rolling resistance characteristic) of the wheel can be changed.

  When the wheel is braked, the camber angle of the wheel is adjusted by the first adjusting means, and the contact ratio of the first tread to the contact of the second tread is increased. Since the first tread in the wheel is configured to have a higher gripping force than the second tread, high braking performance resulting from the high grip characteristic of the wheel can be obtained during braking.

  On the other hand, the camber angle of the wheel is adjusted by the second adjusting means in accordance with the turning state detected by the detecting means during braking of the wheel. Specifically, among the wheels whose camber angles are adjusted by the first adjusting means, the camber angle of the left wheel or the right wheel is adjusted according to the turning state detected by the detecting means.

  When the camber angle of the left or right wheel is changed, the balance of the grip force of the left and right wheels is accordingly increased, and accordingly, the balance of the frictional resistance between the left wheel and the road surface and the frictional resistance between the right wheel and the road surface is relative. Therefore, a moment for rotating the vehicle about the center of gravity of the vehicle can be generated in accordance with the direction of change in the balance of the frictional resistance. Therefore, by generating such a moment according to the turning state, it is possible to improve the turning state that may impair the turning stability, so that there is an effect that the turning stability is excellent.

  Here, a wheel having two treads having different grip characteristics generally has a change amount of grip force (friction resistance with respect to a road surface) with respect to a change amount of a camber angle in a state where a slip ratio is relatively high such as during braking. There is a big tendency. Therefore, under the situation of turning while braking the wheel, the relative relationship between the grip forces of the left and right wheels can be greatly changed, and the turning state can be effectively improved.

  According to the vehicle control device of the second aspect, in addition to the effect of the vehicle control device of the first aspect, the following effect is obtained. The detection of the turning state of the vehicle by the detection means is performed based on the steering state of the wheels acquired by the steering state acquisition means. At this time, when it is detected that the turning state of the vehicle is an oversteer state, that is, when the vehicle has a tendency to cut inward with respect to the turning direction, the second adjusting means causes the turning direction with respect to the turning direction. The camber angle of the wheel (inner ring) on the inner ring side is adjusted to the side where the contact amount of the second tread is increased, thereby reducing the frictional resistance between the inner ring and the road surface. Therefore, a moment in a direction to cancel the oversteer state is generated in the vehicle, and the turning state of the vehicle can be brought close to the neutral steering state, so that the turning stability of the vehicle can be ensured.

  According to the vehicle control device of the third aspect, in addition to the effect produced by the vehicle control device according to the first aspect, the following effect is obtained. The detection of the turning state of the vehicle by the detection means is performed based on the steering state of the wheels acquired by the steering state acquisition means. At this time, when it is detected that the turning state of the vehicle is an understeer state, that is, when the vehicle has a tendency to bulge outward with respect to the turning direction, the second wheel is adjusted by the second adjusting means. The camber angle of the wheel (outer ring) on the side is adjusted to the side where the ground contact amount of the second tread is increased, thereby reducing the frictional resistance between the outer ring and the road surface. Therefore, a moment is generated in the vehicle in a direction that cancels the understeer state, so that the turning state of the vehicle can be brought close to the neutral steering state, and the turning stability of the vehicle can be ensured.

  In addition to the effect which the vehicle control apparatus of Claim 2 or 3 has, the vehicle control apparatus of Claim 4 has the following effects. The camber angle is adjusted by the second adjusting means only when the turning state of the vehicle detected by the detecting means is an oversteer state exceeding a predetermined level or an understeer state exceeding a predetermined level. Can be reliably provided, and the camber angle is not adjusted by the second adjusting means in a light oversteer state or understeer state that does not affect the turning stability even if the vehicle is turned as it is. There is an effect that energy required for adjustment can be omitted.

  The vehicle according to claim 5 has the same effect as the vehicle control device according to claim 1.

It is the schematic diagram which showed typically the vehicle carrying the control apparatus in one Embodiment of this invention. It is a front view of a suspension apparatus. It is the block diagram which showed the electric constitution of the control apparatus. It is a flowchart which shows a 1st camber angle adjustment process. It is a flowchart which shows a 2nd camber angle adjustment process. It is a schematic diagram for demonstrating the effect of this invention. It is a graph which shows typically the relation between the slip ratio of a wheel, and the frictional resistance with a road surface.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram schematically showing a vehicle 1 equipped with a control device 100 according to an embodiment of the present invention. Note that arrows UD, LR, and FB in FIG. 1 indicate the up-down direction, the left-right direction, and the front-rear direction of the vehicle 1, respectively.

  First, a schematic configuration of the vehicle 1 will be described. As shown in FIG. 1, the vehicle 1 includes a vehicle body frame BF, a plurality (four wheels in this embodiment) of wheels 2 that support the vehicle body frame BF, and some of the plurality of wheels 2 (this embodiment). In the embodiment, a wheel drive device 3 that rotationally drives the left and right front wheels 2FL, 2FR, a plurality of suspension devices 4 that connect the wheels 2 and the vehicle body frame BF, and a part of the plurality of wheels 2 (this embodiment) The embodiment mainly includes a steering device 5 that steers left and right front wheels 2FL, 2FR).

  Next, the detailed configuration of each part will be described. As shown in FIG. 1, the wheel 2 includes left and right front wheels 2FL and 2FR located on the front side (arrow F direction side) of the vehicle 1 and left and right rear wheels located on the rear side (arrow B direction side) of the vehicle 1. Wheels 2RL and 2RR are provided. In the present embodiment, the left and right front wheels 2FL and 2FR are configured as drive wheels that are rotationally driven by the wheel drive device 3, while the left and right rear wheels 2RL and 2RR are driven as the vehicle 1 travels. It is configured as a driven wheel.

  Further, as shown in FIG. 1, the wheel 2 includes two types of treads of a first tread 21 and a second tread 22, and in each wheel 2, the first tread 21 is disposed inside the vehicle 1, A tread 22 is disposed outside the vehicle 1. In the present embodiment, the widths of both treads 21 and 22 (dimensions in the left-right direction in FIG. 1) are configured to be the same width.

  The first tread 21 and the second tread 22 are made of a material whose hardness is higher than that of the first tread 21, and the first tread 21 has a higher gripping power than the second tread 22. On the other hand, the second tread 22 is configured to have a smaller rolling resistance than the first tread 21 (low rolling characteristics).

  As described above, the wheel drive device 3 is a device for rotationally driving the left and right front wheels 2FL and 2FR, and is configured by an electric motor 3a as described later (see FIG. 3). Further, as shown in FIG. 1, the electric motor 3 a is connected to the left and right front wheels 2 FL and 2 FR via a differential gear (not shown) and a pair of drive shafts 31.

  When the driver operates the accelerator pedal 61, a rotational driving force is applied to the left and right front wheels 2FL, 2FR from the wheel drive device 3, and the left and right front wheels 2FL, 2FR rotate according to the operation amount of the accelerator pedal 61. Driven. The difference in rotation between the left and right front wheels 2FL and 2FR is absorbed by the differential gear.

  The suspension device 4 functions as a so-called suspension for mitigating vibration transmitted from the road surface to the vehicle body frame BF via the wheels 2, and is provided corresponding to each wheel 2 as shown in FIG. It has been. Further, the suspension device 4 in the present embodiment also has a function as a camber angle adjusting mechanism that adjusts the camber angle of the wheel 2.

  Here, with reference to FIG. 2, the detailed structure of the suspension apparatus 4 is demonstrated. FIG. 2 is a front view of the suspension device 4. Here, only the configuration that functions as a camber angle adjusting mechanism will be described, and the configuration that functions as a suspension is the same as a known configuration, and thus description thereof is omitted. Moreover, since the structure of each suspension apparatus 4 is common in each wheel 2, the suspension apparatus 4 corresponding to the right front wheel 2FR is illustrated in FIG. 2 as a representative example. However, in FIG. 2, illustration of the drive shaft 31 and the like is omitted for easy understanding.

  As shown in FIG. 2, the suspension device 4 transmits a knuckle 43 supported by the vehicle body frame BF via a strut 41 and a lower arm 42, an FR motor 44FR that generates a driving force, and a driving force of the FR motor 44FR. The worm wheel 45 and the arm 46 are configured to mainly include a movable plate 47 that is swingably driven with respect to the knuckle 43 by the driving force of the FR motor 44FR transmitted from the worm wheel 45 and the arm 46. .

  The knuckle 43 supports the wheel 2 so as to be steerable. As shown in FIG. 2, the upper end (upper side in FIG. 2) is connected to the strut 41, and the lower end (lower side in FIG. 2) is connected via a ball joint. Are coupled to the lower arm 42.

  The FR motor 44FR applies a driving force for swinging driving to the movable plate 47, is constituted by a DC motor, and a worm (not shown) is formed on its output shaft 44a.

  The worm wheel 45 transmits the driving force of the FR motor 44FR to the arm 46, meshes with a worm formed on the output shaft 44a of the FR motor 44FR, and forms a staggered shaft gear pair together with the worm.

  The arm 46 transmits the driving force of the FR motor 44FR transmitted from the worm wheel 45 to the movable plate 47, and has one end (right side in FIG. 2) via the first connecting shaft 48 as shown in FIG. The other end (left side in FIG. 2) is connected to the upper end (upper side in FIG. 2) via the second connection shaft 49 while being connected to a position eccentric from the rotation shaft 45 a of the worm wheel 45.

  The movable plate 47 supports the wheel 2 in a rotatable manner. As described above, the upper end (upper side in FIG. 2) is coupled to the arm 46, and the lower end (lower side in FIG. 2) is interposed via the camber shaft 50. The knuckle 43 is pivotally supported so as to be swingable.

  According to the suspension device 4 configured as described above, when the FR motor 44FR is driven, the worm wheel 45 rotates and the rotational motion of the worm wheel 45 is converted into linear motion of the arm 46. As a result, when the arm 46 moves linearly, the movable plate 47 is driven to swing with the camber shaft 50 as the swing shaft, and the camber angle of the wheel 2 is adjusted.

  In the present embodiment, the connection shafts 48 and 49 and the rotation shaft 45a of the worm wheel 45 are in the direction from the vehicle body frame BF toward the wheel 2 (arrow R direction). A first camber state positioned in a straight line in the order of the two connecting shafts 49, and a second camber state positioned in a straight line in the order of the rotating shaft 45a, the first connecting shaft 48, and the second connecting shaft 49 (FIG. 2). The camber angle of the wheel 2 is adjusted so as to be in either one of the camber states.

  Thereby, in the state where the camber angle of the wheel 2 is adjusted, even if an external force is applied to the wheel 2, no force in the direction of rotating the arm 46 is generated, and the camber angle of the wheel 2 can be maintained. .

  In the present embodiment, in the first camber state, the camber angle of the wheel 2 is adjusted to the first camber angle (3 ° in the present embodiment), and a negative camber is imparted to the wheel 2. As a result, the ground contact ratio of the first tread 21 with respect to the ground contact of the second tread 22 is increased, so that the high grip characteristics of the first tread 21 are exhibited and the canvas last is generated to ensure the grip performance. it can.

  On the other hand, in the second camber state (the state shown in FIG. 2), the camber angle of the wheel 2 is adjusted to the second camber angle (0 ° in the present embodiment). Here, since the second tread 22 is made of a material having higher hardness than the first tread 21, when the camber angle of the wheel 2 is adjusted to 0 °, the grounding of the first tread 21 is the first. Blocked by the 2 tread 22. As a result, the contact ratio of the second tread 22 with respect to the contact of the first tread 21 is increased, so that the low rolling characteristics of the second tread 22 are exhibited, and the occurrence of canvas rust is avoided, thereby reducing fuel consumption. be able to.

  Returning to FIG. The steering device 5 is a device for steering an operation of the steering 63 by the driver to the left and right front wheels 2FL, 2FR, and is configured as a so-called rack and pinion type steering gear.

  According to the steering device 5, the operation (rotation) of the steering 63 by the driver is first transmitted to the universal joint 52 via the steering column 51, and the pinion 53 a of the steering box 53 is changed while the angle is changed by the universal joint 52. Is transmitted as rotational motion. Then, the rotational motion transmitted to the pinion 53a is converted into a linear motion of the rack 53b, and the tie rod 54 connected to both ends of the rack 53b moves by the linear motion of the rack 53b. As a result, the tie rod 54 pushes and pulls the knuckle 55, so that a predetermined steering angle is given to the wheel 2.

  The accelerator pedal 61 and the brake pedal 62 are operation members operated by the driver, and the traveling speed and braking force of the vehicle 1 are determined according to the operation state (depression amount, depressing speed, etc.) of the pedals 61 and 62. The wheel drive device 3 is driven and controlled. The steering 63 is an operating member operated by the driver, and the left and right front wheels 2FL and 2FR are steered by the steering device 5 according to the operating state (rotation angle, rotational speed, etc.).

  The control device 100 is a device for controlling each part of the vehicle 1 configured as described above. For example, the camber angle adjusting device 44 (see FIG. 3) according to the operation state of the pedals 61 and 62 and the steering 63. ) Is controlled.

  Although the details will be described later, the control device 100 that is a vehicle control device or control means of the present invention, when the steering 63 is rotated while depressing the brake pedal 62, that is, when turning while braking the wheel 2, Depending on the turning state, the camber angle of the left wheels 2FL, 2RL and the camber angle of the right wheels 2FR, 2RR are selectively used, thereby providing excellent turning stability.

  Next, a detailed configuration of the control device 100 will be described with reference to FIG. FIG. 3 is a block diagram showing an electrical configuration of the control device 100. As illustrated in FIG. 3, the control device 100 includes a CPU 71, a ROM 72, and a RAM 73, which are connected to an input / output port 75 via a bus line 74. The input / output port 75 is connected to a device such as the wheel drive device 3.

  The CPU 71 is an arithmetic device that controls each unit connected by the bus line 74, and the ROM 72 is a control program executed by the CPU 71 (for example, a program for executing the flowcharts shown in FIGS. 4 and 5), fixed value data, or the like. Is a non-rewritable non-volatile memory.

  The RAM 73 is a memory that stores various data in a rewritable manner when the control program is executed, and is provided with a braking flag 73a as shown in FIG. The braking flag 73a is a flag indicating whether or not the wheel 2 is being braked. When the braking flag 73a is on, the CPU 71 determines that the wheel 2 is being braked (that is, the brake pedal 62 is depressed). On the other hand, if the braking flag 73 is off, the CPU 71 determines that the wheel 2 is not braked.

  As described above, the wheel drive device 3 is a device for rotationally driving the left and right front wheels 2FL, 2FR (see FIG. 1), and an electric motor 3a that applies a rotational driving force to the left and right front wheels 2FL, 2FR. A drive control circuit (not shown) for driving and controlling the electric motor 3a based on an instruction from the CPU 71 is mainly provided. However, the wheel drive device 3 is not limited to the electric motor 3a, and other drive sources can naturally be adopted. Examples of other drive sources include a hydraulic motor and an engine.

  The camber angle adjusting device 44 is a device for adjusting the camber angle of each wheel 2, and as described above, the driving force for swing driving is applied to the movable plate 47 (see FIG. 2) of each suspension device 4. A total of four FL to RR motors 44FL to 44RR to be provided respectively, and a drive control circuit (not shown) for driving and controlling these motors 44FL to 44RR based on instructions from the CPU 71 are mainly provided.

  The vehicle speed sensor device 81 is a device for detecting the ground speed (absolute value and traveling direction) of the vehicle 1 with respect to the road surface and outputting the detection result to the CPU 71, and includes longitudinal and lateral acceleration sensors 81a and 81b. And a processing circuit (not shown) for processing the detection results of the acceleration sensors 81a and 81b and outputting the results to the CPU 71.

  The longitudinal acceleration sensor 81a is a sensor that detects the acceleration in the longitudinal direction (the vertical direction in FIG. 1) of the vehicle 1 (body frame BF), and the lateral acceleration sensor 81b is the lateral direction of the vehicle 1 (body frame BF) ( FIG. 1 is a sensor that detects acceleration in the left-right direction. In the present embodiment, each of the acceleration sensors 81a and 81b is configured as a piezoelectric sensor using a piezoelectric element.

  The CPU 71 time-integrates the detection results (acceleration values) of the respective acceleration sensors 81a and 81b input from the vehicle speed sensor device 81 to calculate speeds in two directions (front and rear and left and right directions), respectively. The ground speed (absolute value and traveling direction) of the vehicle 1 is calculated by combining the components.

  The yaw rate sensor device 82 is a device for detecting the yaw rate of the vehicle 1 and outputting the detection result to the CPU 71. The yaw rate sensor detects the rotational angular velocity around the vertical axis of the body frame BF in association with the rotational direction. 82a and a processing circuit (not shown) for processing the detection result and outputting the result to the CPU 71. The yaw rate is a rotation in a plane (plane including the arrows FD and LR in FIG. 1) that is horizontal to the road surface with the vertical axis (the axis in the direction of arrow UD in FIG. 1) as the center. ) Angular velocity.

  In the present embodiment, the yaw rate sensor 82a is constituted by an optical gyro sensor that detects the rotational angular velocity by the Sagnac effect. However, it is naturally possible to employ other types of gyro sensors. Examples of other types of gyro sensors include mechanical and fluid gyro sensors.

  The accelerator pedal sensor device 61a is a device for detecting the operation amount of the accelerator pedal 61 and outputting the detection result to the CPU 71. An angle sensor (not shown) for detecting the depression amount of the accelerator pedal 61; It mainly includes an output circuit (not shown) that processes the detection result of the angle sensor and outputs it to the CPU 71.

  The brake pedal sensor device 62a is a device for detecting the operation amount of the brake pedal 62 and outputting the detection result to the CPU 71. An angle sensor (not shown) for detecting the depression amount of the brake pedal 62; It mainly includes an output circuit (not shown) that processes the detection result of the angle sensor and outputs it to the CPU 71.

  The steering sensor device 63a is a steering state acquisition means of the present invention, and is a device for detecting the operation amount of the steering 63 and outputting the detection result to the CPU 71, and an angle sensor for detecting the rotation angle of the steering 63. (Not shown) and an output circuit (not shown) for processing the detection result of the angle sensor and outputting it to the CPU 71 are mainly provided.

  In the present embodiment, each angle sensor is configured as a contact type potentiometer using electric resistance. Further, the CPU 71 obtains the depression speed of the pedals 61 and 62 and the rotation speed of the steering 63 by differentiating the detection results (operation amounts) of the angle sensors input from the sensor devices 61a, 62a, and 63a with respect to time. be able to.

  Other input / output devices 90 shown in FIG. 3 include, for example, a wheel rotational speed sensor device that detects the rotational speeds of the wheels 2FL to 2RR, an acceleration sensor device that detects longitudinal and lateral accelerations of the vehicle 1, and the like. Is exemplified.

  Next, the first camber angle adjustment process executed by the control device 100 in the vehicle 1 having the above configuration will be described with reference to FIG. FIG. 4 is a flowchart showing the first camber angle adjustment process. The first camber angle adjustment process is a process of adjusting the camber angle of the wheel 2 according to whether or not the wheel 2 is being braked (that is, the operation state of the brake pedal 62), and the control device 100 is turned on. While it is being executed, it is repeatedly executed by the CPU 71 (for example, at intervals of 0.1 s).

  In the first camber angle adjustment process, first, it is determined whether or not the wheel 2 is being braked (S11). In the present embodiment, it is determined whether or not the wheel 2 is being braked based on the input value from the brake pedal sensor device 62a (that is, the depression speed or depression amount of the brake pedal). More specifically, it is determined that the wheel 2 is being braked when the depression speed of the brake pedal 62 is equal to or greater than a predetermined threshold value or when the depression amount of the brake pedal 62 is equal to or greater than the predetermined threshold value.

  If the result of the determination in S11 is that the wheel 2 is being braked (S11: Yes), the camber angle adjusting device 44 is operated, and the camber angles θ of all the wheels 2 (2FL to 2RR) are set to the first camber angle θ1. (S12), the braking flag 73a is turned on (S13), and the first camber angle adjustment process is terminated.

  Note that the process of S12 corresponds to the first adjusting means in the present invention. Further, in “operation of the camber angle adjusting device 44” in S12, when the camber angle θ of the wheel 2 has already been the first camber angle θ1, or when the camber angle θ1 is being shifted to the first camber angle θ1. Includes an operation for maintaining the state.

  On the other hand, if the result of the determination in S11 is that the wheel 2 is not being braked (S11: No), the camber angle adjusting device 44 is operated to set the camber angles θ of all the wheels 2 (2FL to 2RR) to the second camber. The angle θ2 is adjusted (S14), the braking flag 73a is turned off (S15), and the first camber angle adjustment process is terminated. The “operation of the camber angle adjusting device 44” in S14 includes the case where the camber angle θ of the wheel 2 has already been the second camber angle θ2 or when the camber angle θ2 is being shifted to the second camber angle θ2. Includes an operation for maintaining the state.

  According to the first camber angle adjustment process, when the wheel 2 is being braked, the camber angle θ of the wheel 2 is adjusted to the first camber angle θ1 by the process of S12. As a result, the ground contact ratio of the first tread 21 with respect to the ground contact of the second tread 22 is increased, the high grip characteristics of the first tread 21 are exhibited, and high braking performance can be obtained.

  On the other hand, if the wheel 2 is not being braked, the camber angle θ of the wheel 2 is adjusted to the second camber angle θ2 by the process of S14. As a result, the low rolling characteristics of the second tread 22 are exhibited, and fuel consumption can be reduced.

  Next, a second camber angle adjustment process executed by the control device 100 will be described with reference to FIG. FIG. 5 is a flowchart showing the second camber angle adjustment process. The second camber angle adjustment process is a process of adjusting the camber angle of the wheel 2 according to the turning state when turning while braking the wheel 2, and is performed by the CPU 71 while the control device 100 is powered on. It is executed repeatedly (for example, at intervals of 0.1 s).

  In the second camber angle adjustment process, first, it is confirmed whether or not the braking flag 73a is on (S21). At this time, if the braking flag 73a is off (S21: No), the second camber angle adjustment process is terminated.

  On the other hand, if the braking flag 73a is on (S21: Yes), the turning state is detected (S22). The process of S22 corresponds to the detection means of the present invention. In the present embodiment, the turning state of the vehicle 1 is detected from the target yaw rate Yref of the vehicle 1 determined based on the operation of the steering 63 and the actual yaw rate Y actually generated in the vehicle 1. In the present embodiment, whether the turning state of the vehicle 1 is oversteer or understeer is detected from the sign of the target yaw rate and the deviation (Y−Yref) obtained by subtracting the target yaw rate Yref from the actual yaw rate Y. .

  Specifically, when the target yaw rate Yref is a positive value (Yref> 0) and the deviation (Y−Yref) is a positive value, the turning state of the vehicle 1 is in the turning direction of the vehicle 1. On the other hand, it is determined that the state is an oversteer state that cuts inward. Similarly, when the target yaw rate Yref is a negative value (Yref <0) and the deviation (Y−Yref) is a negative value, it is determined that the turning state of the vehicle 1 is an oversteer state. .

  On the other hand, when the target yaw rate Yref is a positive value (Yref> 0) and the deviation (Y−Yref) is a negative value, the turning state of the vehicle 1 is outside the turning direction of the vehicle 1. Judged to be in an understeer state. Similarly, when the target yaw rate Yref is a negative value (Yref <0) and the deviation (Y−Yref) is a positive value, it is determined that the turning state of the vehicle 1 is an understeer state.

  The target yaw rate Yref is calculated from the rotation angle (steering angle) of the steering 63 obtained from the value inputted from the steering sensor 63a and the ground speed of the vehicle 1 obtained from the value inputted from the vehicle speed sensor device 81. can do. On the other hand, the actual yaw rate Y can be obtained from the yaw rate sensor device 82.

  After detecting the turning state of the vehicle 1 in S22, it is determined whether or not the detected turning state is an oversteer state (OS) exceeding a predetermined level (S23). In S23, when the absolute value of the actual yaw rate Y is a predetermined multiple (for example, 1.1 times) or more of the absolute value of the target yaw rate Yref, it is determined that the oversteer state exceeds the predetermined level.

  In S23, when it is determined that the oversteer state exceeds the predetermined level (S23: Yes), the camber angle adjusting device 44 is operated to set the camber angle θ of the wheel 2 on the inner ring side with respect to the turning direction to the second camber. The angle θ2 is adjusted (S24), and the second camber angle adjustment process is terminated.

  In S24, if the vehicle 1 is turning left, the camber angle θ of the left wheels 2FL and 2RL is adjusted to the second camber angle θ2. On the other hand, if the vehicle 1 is turning right, the camber angle θ of the right wheels 2FR and 2RR is adjusted to the second camber angle θ2. The “operation of the camber angle adjusting device 44” in S24 includes the case where the camber angle θ of the wheel 2 to be adjusted has already been the second camber angle θ2, or the transition to the second camber angle θ2. If it is in the middle, the operation of maintaining the camber angle is also included.

  On the other hand, when it is determined in S23 that the oversteer state is equal to or lower than the predetermined level (S23: No), it is determined whether or not the turning state of the vehicle 1 is an understeer state (US) exceeding the predetermined level (S25). ). In S25, when the absolute value of the actual yaw rate Y is equal to or less than a predetermined multiple (for example, 0.9 times) of the absolute value of the target yaw rate Yref, it is determined that the understeer state exceeds the predetermined level.

  At this time, when it is determined that the understeer state exceeds the predetermined level (S25: Yes), the camber angle adjusting device 44 is operated to set the camber angle θ of the wheel 2 on the outer ring side with respect to the turning direction to the second camber angle. The angle is adjusted to θ2 (S26), and the second camber angle adjustment process is terminated.

  In S26, if the vehicle 1 is turning left, the camber angle θ of the right wheels 2FR and 2RR is adjusted to the second camber angle θ2. On the other hand, if the vehicle 1 is turning right, the camber angle θ of the left wheels 2FL and 2RL is adjusted to the second camber angle θ2. The “operation of the camber angle adjusting device 44” in S26 includes the case where the camber angle θ of the wheel 2 to be adjusted has already been the second camber angle θ2, or the transition to the second camber angle θ2. If it is in the middle, the operation of maintaining the camber angle is also included.

  On the other hand, if it is determined in S25 that the understeer state is equal to or lower than the predetermined level (S25: No), the second camber angle adjustment process is terminated without adjusting the camber angle of the wheel 2.

  According to the second camber angle adjusting process described above, when it is detected that the turning state while braking the wheel 2 is an oversteer state or an understeer state exceeding a predetermined level, the process of S24 or S26 is executed. The camber angle θ of the left wheel 2FL, 2RL or the right wheel 2FR, 2RR is adjusted to the second camber angle θ2.

  The processes of S24 and S26 correspond to the second adjusting means in the present invention. Here, with reference to FIG. 6, the effect of the present invention produced by executing the processing of S24 and S26 when turning while braking the wheel 2 will be described.

  FIG. 6A is a schematic diagram for explaining the effect obtained by executing the process of S24 in the second camber angle adjustment process (see FIG. 5). A vehicle 1a illustrated on the lower side of FIG. 6A is a vehicle 1 that is going to turn left with the traveling line T as a target while braking the wheels 2. Since the vehicle 1a brakes the wheels 2, the process of S12 is executed in the first camber angle adjustment process (see FIG. 4), whereby the camber angles θ of all the wheels 2 (2FL to 2RR) are changed to the first. The camber angle θ1 is adjusted.

  The vehicle 1OS illustrated on the upper side of FIG. 6A is the vehicle 1 that is determined to be in an oversteer state exceeding a predetermined level by the process of S23 of the second camber angle adjustment process (see FIG. 5). According to the second camber angle adjustment processing, when it is determined that the turning state is an oversteer state exceeding a predetermined level, the processing of S24 is executed, so the left wheels 2FL and 2RL on the inner wheel side with respect to the turning direction are executed. Is adjusted to the second camber angle θ2.

  By changing the camber angle θ of the left wheels 2FL and 2RL from the first camber angle θ1 to the second camber angle θ2, the grip force of the left wheels 2FL and 2RL is lowered, and the frictional resistance with the road surface is also lowered. As a result, the frictional resistance between the right wheels 2FR and 2RR and the road surface becomes relatively large, and therefore a moment M1 is generated in a direction that cancels the oversteer state with the vehicle center of gravity O at the center. Due to the generation of the moment M1, the turning state of the vehicle 1OS can be brought close to the neutral steer state (that is, the state where the actual yaw rate Y and the target yaw rate Yref are equal), so that the turning state is improved and stable turning performance is achieved. Obtainable.

  FIG. 6B is a schematic diagram for explaining the effect obtained by executing the process of S26 in the second camber angle adjustment process (see FIG. 5). A vehicle 1a illustrated on the lower side of FIG. 6 (b) is a vehicle 1 that is going to turn left with the traveling line T as a target while braking the wheel 2, and a camber for all the wheels 2 (2FL to 2RR). The angle θ is adjusted to the first camber angle θ1.

  The vehicle 1US illustrated on the upper side of FIG. 6B is a vehicle 1 that is determined to be in an understeer state exceeding a predetermined level by the process of S25 of the second camber angle adjustment process (see FIG. 5). According to the second camber angle adjustment process, if it is determined that the turning state is an understeer state exceeding a predetermined level, the process of S26 is executed, so that the camber of the right wheels 2FR and 2RR on the outer wheel side with respect to the turning direction is executed. The angle θ is adjusted to the second camber angle θ2.

  By changing the camber angle θ of the right wheels 2FR and 2RR from the first camber angle θ1 to the second camber angle θ2, the gripping force of the right wheels 2FR and 2RR is lowered, thereby reducing the frictional resistance with the road surface. As a result, the frictional resistance between the left wheels 2FL, 2RL and the road surface becomes relatively large, and a moment M2 is generated around the vehicle center of gravity O in a direction that cancels the understeer state. Due to the generation of the moment M2, the turning state of the vehicle 1OS can be brought close to the neutral steer state, so that the turning state is improved and stable turning performance can be obtained.

  Here, with reference to FIG. 7, when turning while braking the wheel 2, the usefulness of selectively using the camber of the left wheel 2FL, 2RL and the camber of the right wheel 2FR, 2RR depending on the turning state will be described. To do.

  FIG. 7 is a graph schematically showing the relationship between the slip ratio of the wheel 2 and the road surface frictional force (friction resistance with the road surface) μ. The horizontal axis in the graph of FIG. 7 is an axis indicating the slip rate of the wheel 2 and indicates that the value of the slip rate increases as the distance from the origin increases. On the other hand, the vertical axis represents the wheel 2 and the road surface frictional force μ, and indicates that the value of μ increases as the distance from the origin increases.

  In FIG. 7, curve A is a curve showing the relationship between the camber angle θ of the wheel 2 and the first camber angle θ1, and the curve B is the camber angle θ of the wheel 2 being the second camber angle θ2. It is a curve which shows the relationship between both in a certain case.

  As shown in FIG. 7, the wheel 2 having two treads (first tread 21 and second tread 22) having different gripping forces has a first camber angle θ1 in a region where the slip ratio is relatively high (curved line). The difference in μ tends to be large between A) and the second camber angle θ2 (curve B). That is, the change amount of the road surface friction force μ tends to be large with respect to the change amount of the camber angle θ of the wheel 2.

  Since the slip rate of the braked wheel 2 is large (for example, X or more), the road surface frictional force μ can be significantly changed when the camber angle θ of the wheel 2 is changed from θ1 to θ2. Therefore, in the situation where the wheel 2 is turned while being braked, the camber angles of the left wheels 2FL and 2RL and the camber angles of the right wheels 2FR and 2RR are made different from each other, and are generated in the left wheels 2FL and 2RL and the right wheels 2FR and 2RR, respectively. Since the balance of the road surface frictional force μ changes greatly, as a result, a moment in a direction that cancels the turning state can be generated with a significant magnitude. Therefore, when turning while braking the wheel 2, the turning state can be effectively improved by properly using the camber of the left wheel 2FL, 2RL and the camber of the right wheel 2FR, 2RR according to the turning state.

  As described above, according to the control device 100 of the present embodiment, when the turning state of the vehicle 1 that turns while braking the wheel 2 becomes a predetermined state, the left wheel 2FL according to the turning state. , 2RL or the right wheel 2FR, 2RR is adjusted to the second camber angle, the relative balance of the grip force of the left and right wheels is changed, the friction resistance between the left wheel 2FL, 2RL and the road surface, and the right wheel 2FR, The relative balance between 2RR and the frictional resistance between the road surface is changed. As a result, it is possible to generate a moment that rotates around the center of gravity of the vehicle, so by generating a moment in a direction according to the turning state, the turning state can be improved and excellent turning stability can be obtained. it can.

  Here, according to the control device 100 of the present embodiment, in S23 and S25 in the second camber angle adjustment process (see FIG. 5), a predetermined turning state (specifically, an oversteer state exceeding a predetermined level or a predetermined level) In the case of an understeer state exceeding the level), the camber angle of the left wheel 2FL, 2RL or the right wheel 2FR, 2RR is changed. Therefore, while it is possible to improve the turning state that may impair the turning stability, the camber angle of the wheel 2 is not changed in a light oversteering state or understeering state that does not affect the turning stability. It can save energy required.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, the numerical values given in the above embodiment are merely examples, and other numerical values can naturally be adopted.

  Moreover, in the said embodiment, although the wheel which divided | segmented the tread into 2 width directions and arrange | positioned the two treads (1st tread 21 and 2nd tread 22) from which grip force differs was illustrated as the wheel 2, the division | segmentation number of a tread Is not limited to two. For example, the tread is divided into three in the width direction, the first tread 21 is arranged in the center, and the wheel in which the second tread 22 is arranged on both sides of the first tread 21 or the second tread 22 is arranged in the center. A wheel in which the first tread 21 is disposed on both sides of the second tread 22 may be adopted as the wheel 2.

  In the above embodiment, the first tread 21 of the wheel 2 is arranged inside the vehicle 1 and the second tread 22 is arranged outside the vehicle 1. However, the first tread 21 is arranged outside the vehicle 1. It is good also as a structure which arrange | positions and arrange | positions the 2nd tread 22 inside the vehicle 1. FIG. In such a case, the first camber angle is not a negative camber but a positive camber.

  Moreover, in the said embodiment, although the vehicle 1 which has the wheel 2 of each two wheels on the left and right was illustrated, if it is a vehicle which has a left-right wheel, the number of the wheels 2 will not be limited.

  In the above embodiment, the rotation angle (steering angle) of the steering 63 is used when calculating the target yaw rate Yref. However, in the case of automatic steering, the target yaw rate Yref is automatically set by the control device according to the driving state. Steering angle may be used. In such a case, the process of acquiring information on the automatically set steering angle corresponds to the steering state acquisition means of the present invention.

  Moreover, in the said embodiment, when the turning state of the vehicle 1 turning while braking the wheel 2 becomes a predetermined state, the wheel 2 that is inside or outside with respect to the turning direction according to the turning state. The camber angle is adjusted to the second camber angle, and the relative grip force of the left and right wheels is changed. However, the camber angle on the negative side is further adjusted than the camber angle at the time of braking. The relative grip force of the left and right wheels may be changed by further increasing the contact ratio of the first tread 21 to the ground. In such a case, the camber angle of the outer wheel 1 is adjusted when the turning state of the vehicle 1 is an oversteer state, and the camber angle of the inner wheel 1 is adjusted when the vehicle 1 is in an understeer state.

  Moreover, in the said embodiment, when the turning state of the vehicle 1 turning while braking the wheel 2 becomes a predetermined state, the camber angle of the wheel 2 to be controlled is adjusted to the second camber angle. However, it is not limited to the second camber angle, and may be a predetermined angle in a direction in which the amount of contact of the second tread 22 increases.

  In the above embodiment, the camber angle of the left wheel 2FL, 2RL or the right wheel 2FR, 2RR is adjusted to the second camber angle according to the turning state of the vehicle 1 turning while braking the wheel 2. When the wheel 2 is not braked and the slip rate is low, as described above with reference to FIG. 7, the change in μ due to the difference in the camber angle of the wheel 2 is small. Compared to the case where the wheel 2 is braked as in the above-described embodiment, it is lower. Therefore, when an oversteer state of a predetermined level or more occurs when the wheel 2 is not braked, the camber angle of the rear wheel 2RL and / or the rear wheel 2RR is adjusted to the first camber angle side, A configuration may be adopted in which the oversteer state is improved by relatively increasing the frictional resistance between the wheels 2RL and 2RR and the road surface. Similarly, when an understeer state of a predetermined level or higher occurs when the wheel 2 is not braked, the camber angle of the front wheel 2FL and / or the front wheel 2FR is adjusted to the first camber angle side, and the front wheels 2FL, The understeer state may be improved by relatively increasing the frictional resistance between 2FR and the road surface.

  Further, a map (for example, a map that stores the relationship shown in FIG. 7 as content) that correlates the slip ratio and the frictional resistance μ with the road surface according to the camber angle of the wheel 2 is stored. In the second camber angle adjustment process (see FIG. 5), a braking flag is provided in which a configuration capable of detecting the rate (for example, a wheel rotation speed sensor device including a rotation speed sensor that detects the rotation speed of each wheel 2) is provided 73a is on, but when the slip ratio of the wheel 2 is smaller than a predetermined value, the turning state may be improved by changing the camber angle of the front and rear wheels without performing the processing of S24 and S26.

1 Vehicle 100 Control Device (Vehicle Control Device, Control Unit)
2 Wheel 2FL, 2RL Left wheel (wheel)
2FR, 2RR Right wheel (wheel)
21, 221 First tread 22 Second tread 44 Camber angle adjusting device

Claims (5)

A vehicle body, wheels disposed on the left and right of the vehicle body to support the vehicle body, and a camber angle adjusting device for adjusting a camber angle of the wheel,
The wheel includes a first tread and a second tread arranged on the inner side or the outer side of the vehicle body with respect to the first tread, and the first tread has a gripping force as compared with the second tread. In the vehicle control device configured to have a high characteristic and used in a vehicle configured to have a characteristic in which the second tread has a lower rolling resistance than the first tread, and controls the camber angle adjusting device,
First adjusting means for adjusting a camber angle of the wheel so that a contact ratio of the first tread with respect to a contact of the second tread is increased when the wheel is braked;
Detecting means for detecting a turning state;
Of the wheels whose camber angles are adjusted by the first adjusting means according to the turning state detected by the detecting means during braking of the wheels, the camber angles of the left wheels or the right wheels And a second adjusting means for controlling the turning state of the vehicle by adjusting the vehicle control device. Steering state acquisition means for acquiring the steering state of the wheel,
The detection means detects the turning state of the vehicle based on the steering state acquired by the steering state acquisition means,
The second adjusting means includes
Of the wheels whose camber angle has been adjusted by the first adjusting means when the detecting means detects that the turning state is an oversteer state, the wheel that is on the inner ring side with respect to the turning direction 2. The vehicle control device according to claim 1, wherein the camber angle of the second tread is adjusted to a side where the contact amount of the second tread increases. Steering state acquisition means for acquiring the steering state of the wheel,
The detection means detects the turning state of the vehicle based on the steering state acquired by the steering state acquisition means,
The second adjusting means includes
Of the wheels whose camber angle is adjusted by the first adjusting means when the turning state is detected by the detecting means as an understeer state, the wheels on the outer wheel side with respect to the turning direction The vehicle control device according to claim 1, wherein the camber angle is adjusted to a side where the ground contact amount of the second tread increases.   The second adjusting means can be used by the first adjusting means only when the detecting means detects that the turning state of the vehicle is an oversteer state exceeding a predetermined level or an understeer state exceeding a predetermined level. 4. The vehicle control device according to claim 2, wherein a camber angle of the left wheel or the right wheel among the wheels whose angles are adjusted is adjusted. 5. A vehicle body, wheels arranged on the left and right of the vehicle body to support the vehicle body, a camber angle adjusting device for adjusting the camber angle of the wheel, and a control means for controlling the camber angle adjusting device,
The wheel includes a first tread and a second tread arranged on the inner side or the outer side of the vehicle body with respect to the first tread, and the first tread has a gripping force as compared with the second tread. The second tread is configured to have a low rolling resistance as compared with the first tread, and is configured to have high characteristics.
The control means includes first adjusting means for adjusting a camber angle of the wheel so that a contact ratio of the first tread to a contact of the second tread is increased when the wheel is braked. In the vehicle
Detecting means for detecting a turning state of the vehicle;
The control means includes the left wheel or the right wheel among the wheels whose camber angle is adjusted by the first adjusting means according to the turning state detected by the detecting means during braking of the wheel. A vehicle further comprising second adjusting means for controlling a turning state of the vehicle by adjusting a camber angle of the wheel.

Images