JP2012056394A - Vehicle controller and vehicle control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for enhancing stability at the time of braking in a vehicle of which the gravity center position is deviated.SOLUTION: This vehicle controller 1 includes an active stabilizer device 10 as a tread load regulating part for making tread loads of front wheels and rear wheels get different in left and right wheels, a target yaw rate setting part 102 for setting a target yaw rate, and a yaw rate control part 104 for regulating an actual yaw rate. The yaw rate control part 104 generates the first yaw moment in a side higher in braking force distribution, and the second yaw moment reverse-directional to the first yaw moment in a side lower in the braking force distribution, out of the front wheels and rear wheels, by making the tread loads of the front wheels and the rear wheels respectively get different in the left and the right wheels at the time of braking, and makes the actual yaw rate get near to the target yaw rate by the first yaw moment and the second yaw moment.

Description

  The present invention relates to a vehicle control device and a vehicle control method.

  Vehicles are required to have stability during running and braking. On the other hand, for example, Patent Document 1 discloses a stabilizer control device that adjusts the roll rigidity of a stabilizer based on a deviation in the vehicle width direction of the center of gravity of the vehicle as a configuration for causing the vehicle to travel stably. . In this stabilizer control device, the target value of the roll rigidity of the stabilizer set based on the roll state of the vehicle is changed based on the deviation in the vehicle width direction of the center of gravity position of the vehicle. At this time, the target value of the roll stiffness is corrected to a value that can eliminate the roll steer caused by the shift of the center of gravity position and the left-right difference of the roll moment during steering. As a result, when the position of the center of gravity is biased, roll steer is suppressed during straight travel, and left / right differences such as the yaw rate and roll rate are reduced during left / right steering, improving straight travel performance and steering feeling.

  Further, Patent Document 2 discloses a configuration in which the difference in the axial weight of the left and right wheels is changed by changing the weight distribution in the left and right direction of the fuel tank during straight braking, thereby improving the vehicle stability during straight braking. ing. Patent Document 3 discloses a configuration that prevents the yaw moment from being generated around the center of gravity of the vehicle by making the braking / driving force generated in each wheel the same in consideration of the ground load of each wheel. ing.

JP 2007-245960 A JP 2009-184471 A Japanese Patent Laid-Open No. 10-315945

  Normally, the vehicle is set to generate an appropriate yaw rate (hereinafter, this yaw rate will be referred to as a “target yaw rate” as appropriate) according to the running state. For example, the target yaw rate in the straight traveling state is 0, and in the curved state, the target yaw rate is determined according to the steering angle of the steering.

  In a state where the center of gravity position of the vehicle is biased, a yaw moment (hereinafter, this yaw moment is appropriately referred to as a “bias yaw moment”) due to the bias of the center of gravity position may occur during braking. In this case, the yaw rate generated in the vehicle (hereinafter, this yaw rate is referred to as “actual yaw rate” as appropriate) is deviated from the target yaw rate due to the bias yaw moment, and the vehicle is deflected during straight braking or There may be a difference between the left and right steering feelings.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique for improving the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  In order to solve the above-described problems, a vehicle control apparatus according to an aspect of the present invention sets a ground load adjusting unit for making the ground loads of front wheels and rear wheels different between left and right wheels, and a target yaw rate to be generated in the vehicle. A target yaw rate setting unit for controlling the ground load adjusting unit and a yaw rate control unit for adjusting an actual yaw rate generated in the vehicle, wherein the yaw rate control unit is configured to control each of the front and rear wheels during braking. Different ground contact loads on the left and right wheels generate the first yaw moment on the front and rear wheels where the braking force distribution is larger and the second yaw moment opposite to the first yaw moment on the smaller braking force distribution side The actual yaw rate is made closer to the target yaw rate by the first yaw moment and the second yaw moment.

  According to this aspect, it is possible to improve the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  In the above aspect, the yaw rate control unit may simultaneously generate the first yaw moment and the second yaw moment. According to this aspect, it can prevent more reliably that a roll generate | occur | produces in a vehicle. The yaw rate control unit may alternately generate the first yaw moment and the second yaw moment. According to this aspect, the load on the vehicle body can be reduced.

  In the above aspect, the actual yaw rate may include a yaw rate due to a biased yaw moment generated according to a bias in the position of the center of gravity of the vehicle. Also according to this aspect, it is possible to improve the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  Further, in the above aspect, the ground load adjusting unit includes a stabilizer bar for causing a reaction force corresponding to a twist amount to act on the front wheel side axle and the rear wheel side axle, and an actuator for changing the twist amount of the stabilizer bar. A stabilizer having the following may be included. According to this aspect, it is possible to easily perform the yaw rate adjustment control at a lower cost than in the case of adding a dedicated mechanism for performing the yaw rate adjustment control.

  In the above aspect, the stabilizer bar includes a bar extending in the vehicle width direction of the vehicle and connected to the left and right front wheels at an end portion, and a bar extending in the vehicle width direction of the vehicle and connected to the left and right rear wheels at the end portion. And may be included. Also according to this aspect, it is possible to improve the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  In the above aspect, the stabilizer bar extends in the front-rear direction of the vehicle and has a bar to which the right front wheel and the right rear wheel are connected to the end, and the left front wheel and the left rear wheel connect to the end that extends in the front-rear direction of the vehicle. May be included. Also according to this aspect, it is possible to improve the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  Another aspect of the present invention is a vehicle control method. In this vehicle control method, the ground contact loads on the left and right wheels of the front and rear wheels are made different during braking, and the first yaw moment is set on the larger braking force distribution side of the front wheels and the rear wheel, and the lower braking force distribution side. A second yaw moment in a direction opposite to the first yaw moment is generated, and the actual yaw rate generated in the vehicle is brought close to a target yaw rate to be generated in the vehicle by the first yaw moment and the second yaw moment. Also according to this aspect, it is possible to improve the stability at the time of braking in a vehicle in which the position of the center of gravity is biased.

  ADVANTAGE OF THE INVENTION According to this invention, the stability at the time of braking in the vehicle where the gravity center position is biased can be improved.

1 is a block diagram illustrating a schematic configuration of a vehicle control device according to a first embodiment. It is the schematic of an actuator and a right stabilizer bar. It is a schematic diagram for demonstrating the yaw rate adjustment control which concerns on this embodiment. 3 is a yaw rate adjustment control flowchart of the vehicle control device according to the first embodiment. It is a block diagram which shows schematic structure of the vehicle control apparatus which concerns on Embodiment 2. FIG. It is a schematic diagram for demonstrating the structure of the vehicle control apparatus which concerns on Embodiment 3. FIG.

  Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and repeated descriptions are omitted as appropriate.

(Embodiment 1)
FIG. 1 is a block diagram illustrating a schematic configuration of the vehicle control device according to the first embodiment. As shown in FIG. 1, the vehicle control device 1 according to the present embodiment includes an active stabilizer device 10 (ground load adjusting unit) disposed on each of the front wheel side and the rear wheel side of the vehicle, a CPU, a ROM, and a RAM. An electronic control unit (hereinafter referred to as “ECU”) 100 configured mainly by a computer having the above-described components is provided. The ROM of the ECU 100 stores a roll suppression program, a yaw rate adjustment control program, various data, and the like. The ECU 100 can be realized in hardware by elements and circuits such as a computer CPU and memory, and is realized in software by a computer program or the like. Here, the ECU 100 is realized by cooperation thereof. It is drawn as a functional block. Therefore, those skilled in the art will understand that these functional blocks can be realized in various forms by a combination of hardware and software.

  The active stabilizer devices 10 disposed on the front wheel side and the rear wheel side of the vehicle each include a stabilizer bar 20 and an actuator 30. The stabilizer bar 20 is twisted by the roll of the vehicle body, and applies a reaction force corresponding to the amount of twist to the front wheel side axle or the rear wheel side axle (both not shown). The front-wheel side stabilizer bar 20 extends in the vehicle width direction of the vehicle and is connected to the right front wheel 16FR and the left front wheel 16FL at the end, and the rear-wheel side stabilizer bar 20 extends in the vehicle width direction of the vehicle and extends to the right at the end. The rear wheel 16RR and the left rear wheel 16RL are connected. In the present embodiment, the stabilizer bar 20 is divided into two at a substantially central portion, and one end of the right stabilizer bar 22R is left on a wheel holding member (not shown) that holds the right front wheel 16FR or the right rear wheel 16RR. One end of the stabilizer bar 22L is connected to a wheel holding member (not shown) that holds the left front wheel 16FL or the left rear wheel 16RL.

  The other ends of the right stabilizer bar 22R and the left stabilizer bar 22L are connected via an actuator 30 so as to be relatively rotatable. The actuator 30 changes the amount of twist of the stabilizer bar 20. When the actuator 30 is actuated, the right stabilizer bar 22R and the left stabilizer bar 22L rotate relative to each other, and the amount of twist when viewed with the entire stabilizer bar 20 changes. Thereby, the roll rigidity of a vehicle body can be changed to active, and the roll of a vehicle body can be suppressed. In addition, the active stabilizer device 10 can cause the right and left wheels to have different ground loads by causing the actuator 30 to rotate the right stabilizer bar 22R and the left stabilizer bar 22L relative to each other.

  FIG. 2 is a schematic view of the actuator and the right stabilizer bar. The right stabilizer bar 22R includes a torsion bar portion 24 that extends substantially in the vehicle width direction, and an arm portion 26 that is integrally provided at the end of the torsion bar portion 24 on the wheel side and that curves and extends forward or rearward of the vehicle. Become. FIG. 2 illustrates a right stabilizer bar 22R on the front wheel side having an arm portion 26 extending forward of the vehicle. The torsion bar portion 24 is rotatably supported by a support member 40 fixed to the vehicle body. The structure of the left stabilizer bar 22L is the same as that of the right stabilizer bar 22R except that it is bilaterally symmetric. Therefore, the torsion bar portions 24 of the right stabilizer bar 22R and the left stabilizer bar 22L are arranged coaxially with each other. The end of the torsion bar 24 on the vehicle body center side is connected to the actuator 30. The end portion of the arm portion 26 is connected to a part of the wheel holding member (for example, a lower arm) so as to be relatively rotatable.

  The actuator 30 includes a housing 32 and a motor and a speed reducer (both not shown) housed in the housing 32. The housing 32 is held on the vehicle body by a housing holding member 34. The actuator 30 includes two output shafts 36 and 38 disposed coaxially. One end of the output shaft 36 is fixed to the end portion of the housing 32, and the other end is serrated to the end portion of the right stabilizer bar 22R. The output shaft 38 is held rotatably with respect to the housing 32. One end of the output shaft 38 enters the inside of the housing 32 and is connected to the speed reducer. The other end of the output shaft 38 is serrated to the end of the left stabilizer bar 22L. When the actuator 30 operates and the motor rotates, the torsion bar portions 24 of the right stabilizer bar 22R and the left stabilizer bar 22L rotate relative to each other, and a force that is twisted by the stabilizer bar 20 is generated.

  As shown in FIG. 1, the ECU 100 detects a yaw rate sensor 110 that detects an actual yaw rate generated in the vehicle, a steering angle sensor 112 that detects a steering angle of a steering wheel (not shown), and a vehicle speed. A vehicle speed sensor 114 and a G sensor 116 that detects acceleration in the longitudinal direction of the vehicle are connected. The ECU 100 is connected to a height sensor 118 that is attached to the lower part of the vehicle body near the left and right wheels and detects the distance between the lower part of the vehicle body and the road surface by irradiating a laser or the like toward the road surface. Furthermore, the actuator 30 of the active stabilizer device 10 is connected to the ECU 100. The ECU 100 can suppress the roll of the vehicle body by operating the actuator 30 to generate a moment that opposes the roll moment of the vehicle body when the vehicle turns.

  More specifically, the ECU 100 determines the target lateral acceleration based on, for example, the steering angle and the vehicle speed. Subsequently, the torsion angle of the stabilizer bar 20 necessary for suppressing the roll of the vehicle body based on the target lateral acceleration, that is, the target rotation angle of the motor corresponding to the relative rotation angle of the right stabilizer bar 22R and the left stabilizer bar 22L is determined. To do. Then, feedback control based on the deviation between the actual rotation angle of the motor and the target rotation angle is executed.

  Next, yaw rate adjustment control using the active stabilizer device 10 in the present embodiment will be described. FIG. 3 is a schematic diagram for explaining the yaw rate adjustment control according to the present embodiment.

  Usually, the vehicle is set to generate a target yaw rate according to its running state. For example, the target yaw rate in the straight traveling state is 0 ° / sec, and in the curved state, the target yaw rate is determined according to the steering angle of the steering. Here, when the center of gravity position of the vehicle is biased, a bias yaw moment YMb due to the bias of the center of gravity position may occur during vehicle braking. In this case, the actual yaw rate includes the yaw rate generated due to the biased yaw moment YMb, and the actual yaw rate may deviate from the target yaw rate. In contrast, in the vehicle control device 1 according to the present embodiment, the active stabilizer device 10 is used to vary the ground load on the left and right wheels of the front wheel and the rear wheel, so that the sizes of the front wheel side and the rear wheel side are different. Yaw moments in opposite directions are generated. These yaw moments are used to fill the difference between the target yaw rate and the actual yaw rate.

  More specifically, as shown in FIG. 1, the ECU 100 controls the target yaw rate setting unit 102 for setting the target yaw rate to be generated in the vehicle and the actual yaw rate actually generated in the vehicle by controlling the active stabilizer device 10. And a yaw rate control unit 104 for adjusting.

  The target yaw rate setting unit 102 receives the steering angle of the steering wheel from the steering angle sensor 112, the vehicle speed from the vehicle speed sensor 114, and the deceleration applied to the vehicle by braking, that is, the acceleration in the front-rear direction, from the G sensor 116, respectively. Then, the target yaw rate setting unit 102 sets a target yaw rate Yt to be generated in the vehicle body in order to stabilize the posture of the vehicle during braking according to a preset logic. The target yaw rate Yt may be obtained as a turning characteristic prepared in advance by referring to a map in which the target yaw rate is determined with respect to the steering angle or the like, or by substituting the steering angle or the like into a predetermined calculation formula. Also good. This map can be stored in ROM. The target yaw rate setting unit 102 sets the target yaw rate Yt at a predetermined timing such as the timing when the steering angle sensor 112 or the G sensor 116 is input. The target yaw rate setting unit 102 is connected to the yaw rate control unit 104 and transmits the target yaw rate Yt to the yaw rate control unit 104.

  The yaw rate control unit 104 receives the target yaw rate Yt from the target yaw rate setting unit 102. In addition, the measured actual yaw rate Yo is received from the yaw rate sensor 110 that functions as an actual yaw rate acquisition unit in the present embodiment. Then, the yaw rate control unit 104 detects a difference between the target yaw rate Yt and the actual yaw rate Yo, and generates a yaw moment that compensates for this difference (hereinafter, this yaw moment is referred to as “adjustment yaw moment” as appropriate) YMa. In addition, the active stabilizer device 10 disposed on the front wheel side and the rear wheel side of the vehicle is controlled.

  The generation of the adjusting yaw moment YMa is based on the following principle. That is, when the actuator 30 is actuated to twist the stabilizer bar 20, a roll moment is generated on the axle. When a roll moment is generated on the axle, the ground load (the force with which the wheel is pressed against the road surface) of the wheel connected to the axle changes, and the left and right wheels have different values. When the ground contact load of the left and right wheels changes, the radius of the wheel on the side with a large ground load becomes relatively small, and the radius of the wheel on the side with a small ground load becomes relatively large. Here, the magnitude of the braking force of the vehicle transmitted from each wheel to the road surface is inversely proportional to the size of the wheel radius. Therefore, the greater the wheel radius, the smaller the braking force at that wheel. Therefore, by using the active stabilizer device 10 as described above to vary the ground load on the left and right wheels, the braking force of the vehicle on the left and right wheels is the same even if the braking moment in the wheel rotation direction on the left and right wheels is the same. The size of can be different. When the magnitudes of the braking forces on the left and right wheels are different, the vehicle generates a yaw moment in the direction in which the wheels on the side with the larger braking force are inward.

  Further, the braking force distribution of the vehicle is set to be different between the front wheel side and the rear wheel side. For example, the braking force distribution of the vehicle is set so that the front wheel side is large and the rear wheel side is small. Therefore, even if the braking force difference between the left and right wheels is the same on the front wheel side and the rear wheel side, the magnitude of the yaw moment generated due to the braking force difference between the left and right wheels is large in the braking force distribution. The side is larger than the smaller side. Therefore, the first yaw moment YM1 is generated by generating a predetermined roll moment on the side where the braking force distribution is large, and the first yaw moment is generated by generating the roll moment of the same magnitude and in the reverse direction on the side where the braking force distribution is small. A second yaw moment YM2 that is smaller than YM1 and in the reverse direction can be generated. When the first yaw moment YM1 and the second yaw moment YM2 are generated, a combined yaw moment, which is a result of combining the first yaw moment YM1 and the second yaw moment YM2, is applied to the vehicle. This combined yaw moment is the adjusting yaw moment YMa.

  It is to be noted that a predetermined roll moment is generated on the side where the braking force distribution is large, and a roll moment in the opposite direction is generated on the side where the braking force distribution is small with the same magnitude as the predetermined roll moment. Can be countered. Thereby, it can prevent that a roll generate | occur | produces in a vehicle. In addition, since the active stabilizer device 10 can constantly generate the roll moment, the first yaw moment YM1 and the second yaw moment YM2 can be generated constantly. In order to more reliably prevent the rolling from occurring in the vehicle, the generation of the first yaw moment YM1 due to the generation of the rolling moment toward the larger braking force distribution and the generation of the rolling moment toward the smaller braking force distribution. The generation of the second yaw moment YM2 is preferably simultaneous. Here, the term “simultaneously” means that the timing at which the yaw rate control unit 104 transmits control signals to the front wheel side and rear wheel side actuators 30 is the same. In this case, if at least a part of the transmission of the control signal to the actuator 30 on the front wheel side and the transmission of the control signal to the actuator 30 on the rear wheel overlap, it can be “simultaneous”.

  With reference to FIG. 3, as a specific example, a case where a vehicle in which only a driver gets on a right-hand drive vehicle performs straight braking will be described. In this case, the target yaw rate setting unit 102 receives the steering angle 0 ° from the steering angle sensor 112 and sets the target yaw rate Yt = 0 ° / sec. Further, since the center of gravity of this vehicle is biased to the right side, a bias yaw moment YMb that deflects to the left is generated in the vehicle during braking. The yaw rate control unit 104 receives the target yaw rate Yt from the target yaw rate setting unit 102, receives the actual yaw rate Yo from the yaw rate sensor 110, and detects the difference. Then, the yaw rate control unit 104 generates a roll moment in the direction in which the vehicle body rolls to the left on the front wheel side where the braking force distribution is large. As a result, the ground load on the right front wheel 16FR increases and its radius decreases, and the ground load on the left front wheel 16FL decreases and its radius increases. As a result, the braking force on the right front wheel 16FR side increases, the braking force on the left front wheel 16FL side decreases, and a first yaw moment YM1 that deflects rightward is generated on the front wheel side of the vehicle.

  On the other hand, the yaw rate control unit 104 generates a roll moment in the direction in which the vehicle body rolls to the right on the rear wheel side where the braking force distribution is small simultaneously with the generation of the roll moment on the front wheel side. As a result, the ground load on the left rear wheel 16RL increases and its radius decreases, and the ground load on the right rear wheel 16RR decreases and its radius increases. As a result, the braking force on the left rear wheel 16RL side is increased, the braking force on the right rear wheel 16RR side is decreased, and a second yaw moment YM2 that is deflected to the left is generated on the rear wheel side of the vehicle. . The roll moment generated on the front wheel side and the roll moment generated on the rear wheel side are set so as to counterbalance each other.

  Since the first yaw moment YM1 generated on the front wheel side with a large braking force distribution is larger than the second yaw moment YM2 generated on the rear wheel side with a small braking force distribution, the entire vehicle is deflected to the right. An adjusting yaw moment YMa is generated. The adjustment yaw moment YMa cancels the bias yaw moment YMb that is deflected to the left due to the bias of the center of gravity. That is, the actual yaw rate Yo is brought close to the target yaw rate Yt by the adjusting yaw moment YMa.

  The yaw rate control unit 104 causes the front and rear axles to generate the difference between the target yaw rate Yt and the actual yaw rate Yo when the yaw rate adjustment control for bringing the actual yaw rate Yo closer to the target yaw rate Yt by the adjusting yaw moment YMa is not detected. The roll moment may be gradually increased to increase the adjustment yaw moment YMa by a predetermined amount. Alternatively, the yaw rate control unit 104 generates the first yaw moment YM1 and the second yaw moment YM2 necessary for generating the difference between the target yaw rate Yt and the actual yaw rate Yo and the adjustment yaw moment YMa that fills this difference. A map that associates the magnitude of the roll moment may be prepared in advance, and the adjustment yaw moment YMa may be generated based on this map. This map can be stored in ROM. Further, the yaw rate control unit 104 may perform control to generate the adjustment yaw moment YMa when the difference between the target yaw rate Yt and the actual yaw rate Yo exceeds a preset threshold value. The threshold value can be appropriately set based on an experiment or simulation by a designer.

  FIG. 4 is a flowchart of the yaw rate adjustment control of the vehicle control device according to the first embodiment. In the flowchart of FIG. 4, the processing procedure of each part is displayed by a combination of S (acronym for Step) meaning a step and a number. In addition, if a determination process is executed by a process displayed by a combination of S and a number, and the determination result is affirmative, Y (acronym for Yes) is added, for example (Y in S101). On the contrary, if the determination result is negative, N (acronym for No) is added and, for example, (N in S101) is displayed. This flow is repeatedly executed by the yaw rate control unit 104 when, for example, the ignition is turned on, and ends when the ignition is turned off.

  First, the yaw rate control unit 104 determines whether the vehicle is braking (S101). Whether or not the vehicle is braking can be determined, for example, according to the presence or absence of a signal input from a pedal force sensor or a stroke sensor (both not shown) provided on a brake pedal (not shown). If the vehicle is not braking (N in S101), the yaw rate control unit 104 ends this routine. When the vehicle is braking (Y in S101), the yaw rate control unit 104 receives the target yaw rate Yt set from the target yaw rate setting unit 102 (S102). Further, the yaw rate control unit 104 receives the actual yaw rate Yo from the yaw rate sensor 110 (S103).

  Then, the yaw rate control unit 104 determines whether the difference between the actual yaw rate Yo and the target yaw rate Yt is equal to or less than a predetermined threshold value (S104). When the difference exceeds the threshold value (N in S104), the yaw rate control unit 104 generates an adjusting yaw moment YMa to bring the actual yaw rate Yo closer to the target yaw rate Yt (S105). Then, the yaw rate control unit 104 determines again whether the difference between the actual yaw rate Yo and the target yaw rate Yt is equal to or smaller than a predetermined threshold value (S104). If the difference is equal to or smaller than the threshold value (Y in S104), the yaw rate control unit 104 ends this routine.

  As described above, the vehicle control apparatus 1 according to the present embodiment includes the target yaw rate setting unit 102, the yaw rate sensor 110 as the actual yaw rate acquisition unit, and the yaw rate control unit 104. Further, the vehicle control device 1 uses the active stabilizer device 10 as a grounding load adjusting unit for making the grounding loads of the front and rear wheels different between the left and right wheels. Then, the vehicle control device 1 varies the ground loads on the left and right wheels of the front wheel and the rear wheel during braking so that the first yaw moment YM1 is on the side with the larger braking force distribution and the first yaw moment on the side with the smaller braking force distribution. A second yaw moment YM2 opposite to the moment YM1 is generated, and the actual yaw rate Yo is brought close to the target yaw rate Yt by the adjusting yaw moment YMa generated according to the difference in magnitude of these yaw moments. As a result, even when the position of the center of gravity of the vehicle is biased, it is possible to prevent the vehicle from being deflected during straight-ahead braking and to produce a left-right difference in steering feeling during braking. Can be improved.

  In addition, the vehicle control device 1 according to the present embodiment generates a yaw moment on the front and rear wheels by changing the ground load of the left and right wheels on the front and rear wheels using the active stabilizer device 10, so that the actual yaw rate Yo is obtained. It is close to the target yaw rate Yt. Therefore, it is not necessary to add a dedicated mechanism for performing the yaw rate adjustment control as in the configuration in which the vehicle stability at the time of braking is improved by changing the right and left weight distribution of the fuel tank at the time of braking. Therefore, according to the vehicle control device 1 according to the present embodiment, the yaw rate adjustment control can be easily performed at a lower cost.

(Embodiment 2)
The vehicle control device 1 according to the second embodiment includes an actual yaw rate estimation unit as an actual yaw rate acquisition unit, and acquires the actual yaw rate by estimating the actual yaw rate by the actual yaw rate estimation unit. Hereinafter, this embodiment will be described. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the description and illustration are abbreviate | omitted suitably.

  FIG. 5 is a block diagram illustrating a schematic configuration of the vehicle control device according to the second embodiment. As shown in FIG. 5, the vehicle control device 1 according to the present embodiment includes an active stabilizer device 10 (a ground load adjusting unit) disposed on each of the front wheel side and the rear wheel side of the vehicle, and an ECU 100.

  The active stabilizer device 10 includes a stabilizer bar 20 and an actuator 30. The front wheel side stabilizer bar 20 is connected to the right front wheel 16FR and the left front wheel 16FL at the ends, and the rear wheel side stabilizer bar 20 is connected to the right rear wheel 16RR and the left rear wheel 16RL at the ends. These stabilizer bars 20 are divided into a right stabilizer bar 22R and a left stabilizer bar 22L. One end of the right stabilizer bar 22R is connected to a wheel holding member that holds the right front wheel 16FR or the right rear wheel 16RR, and one end of the left stabilizer bar 22L is connected to a wheel holding member that holds the left front wheel 16FL or the left rear wheel 16RL. ing. The other ends of the right stabilizer bar 22R and the left stabilizer bar 22L are connected via an actuator 30 so as to be relatively rotatable.

  The ECU 100 is connected to a steering angle sensor 112 that detects the steering angle of the steering wheel, a vehicle speed sensor 114 that detects the speed of the vehicle, and a G sensor 116 that detects the acceleration of the vehicle. The ECU 100 is connected to a height sensor 118 that detects the distance between the lower portion of the vehicle body and the road surface. Furthermore, the actuator 30 of the active stabilizer device 10 is connected to the ECU 100.

  ECU 100 includes a target yaw rate setting unit 102 for setting a target yaw rate, a yaw rate control unit 104 for adjusting the actual yaw rate, and an actual yaw rate estimation unit 106 that functions as an actual yaw rate acquisition unit.

  The target yaw rate setting unit 102 sets a target yaw rate Yt to be generated in the vehicle body during braking using information received from the steering angle sensor 112, the vehicle speed sensor 114, and the G sensor 116. The target yaw rate setting unit 102 transmits the target yaw rate Yt to the yaw rate control unit 104.

  The actual yaw rate estimation unit 106 receives the steering angle of the steering wheel from the steering angle sensor 112, the vehicle speed from the vehicle speed sensor 114, and the longitudinal acceleration applied to the vehicle by braking from the G sensor 116, respectively. The actual yaw rate estimation unit 106 has a map prepared in advance, in which the bias yaw moment YMb is determined with respect to the bias of the center of gravity position of the vehicle. This map is stored in the ROM of the ECU 100. The deviation of the position of the center of gravity of the vehicle can be obtained based on, for example, the passenger riding state detected from the output value of each height sensor 118 or the output value of a seat belt wearing detection sensor (not shown). Alternatively, the deviation of the position of the center of gravity of the vehicle may be a value measured at the time of shipment at a vehicle manufacturer's manufacturing factory or the like. This value is stored in the ROM as gravity center position information. Then, the actual yaw rate estimation unit 106 estimates the actual yaw rate Yo from the steering angle, the vehicle speed, the acceleration in the front-rear direction, and a map corresponding to the deviation of the center of gravity position. When the above-described center-of-gravity position information is stored in advance as vehicle specifications, a bias yaw moment YMb corresponding to this bias is obtained in advance, and the obtained bias yaw moment YMb is stored in the ROM of the ECU 100. It may be left. In this case, the actual yaw rate estimation unit 106 can estimate the actual yaw rate Yo using the steering angle, the vehicle speed, the longitudinal acceleration, and the bias yaw moment YMb stored in the ROM.

  The yaw rate control unit 104 receives the target yaw rate Yt from the target yaw rate setting unit 102 and receives the actual yaw rate Yo estimated from the actual yaw rate estimation unit 106. As in the first embodiment, the yaw rate control unit 104 detects the difference between the target yaw rate Yt and the actual yaw rate Yo, and generates the adjustment yaw moment YMa that compensates for the difference, so that the front wheel side and the rear side of the vehicle are generated. The active stabilizer device 10 disposed on the wheel side is controlled.

  As described above, in the vehicle control device 1 according to the present embodiment, a map in which the center of gravity position and the bias yaw moment YMb are associated in advance is provided, and the actual yaw rate Yo is estimated using this map. Therefore, the yaw rate adjustment control can be performed earlier than when the yaw rate actually generated by the yaw rate sensor 110 is measured. Therefore, the vehicle stability during braking can be further improved.

(Embodiment 3)
In the vehicle control device 1 according to the first and second embodiments described above, the active stabilizer device 10 includes the stabilizer bar 20 that extends in the vehicle width direction of the vehicle. In contrast, the vehicle control device 1 according to the present embodiment includes a stabilizer bar 20 extending in the front-rear direction of the vehicle. Hereinafter, this embodiment will be described. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the description and illustration are abbreviate | omitted suitably. FIG. 6 is a schematic diagram for explaining the configuration of the vehicle control device according to the third embodiment.

  As shown in FIG. 6, in the vehicle control device 1 according to the present embodiment, the active stabilizer device 10 includes a stabilizer bar 20 that extends in the front-rear direction of the vehicle. The stabilizer bar 20 extends in the front-rear direction of the vehicle and has a right-hand bar connected to the end portion to which the right front wheel 16FR and the right rear wheel 16RR are connected. And left bar.

  In the vehicle control apparatus 1 having such a configuration, for example, the ground load of the right front wheel 16FR is increased by the yaw rate control unit 104, the ground load of the right rear wheel 16RR is decreased, and the ground load of the left front wheel 16FL is decreased. Is reduced, and the active stabilizer device 10 is controlled so that the ground load of the left rear wheel 16RL increases. Thereby, the ground contact load of each wheel is larger for the right front wheel 16FR than the left front wheel 16FL, and for the left rear wheel 16RL, larger than the right rear wheel 16RR. As a result, the braking force BFFR at the right front wheel 16FR is greater than the braking force BFFL at the left front wheel 16FL, and therefore a first yaw moment that is deflected rightward is generated on the front wheel side. Further, since the braking force BFRL at the left rear wheel 16RL is greater than the braking force BFRR at the right rear wheel 16RR, a second yaw moment that is deflected to the left is generated on the rear wheel side. Thus, it is possible to generate the adjusting yaw moment YMa that deflects in the right direction. Further, according to this configuration, it is possible to perform pitch angle control and perform yaw rate adjustment control.

(Embodiment 4)
In the vehicle control device 1 according to the first to third embodiments, the yaw rate control unit 104 generates the first yaw moment YM1 and the second yaw moment YM2 at the same time. In contrast, the vehicle control apparatus 1 according to the present embodiment alternately generates the first yaw moment YM1 and the second yaw moment YM2. Hereinafter, this embodiment will be described. In addition, the same code | symbol is attached | subjected about the structure similar to Embodiment 1, and the description and illustration are abbreviate | omitted suitably.

  In the vehicle control apparatus 1 according to the above-described first to third embodiments, the generation of the first yaw moment YM1 due to the generation of the roll moment toward the larger braking force distribution and the generation of the roll moment toward the smaller braking force distribution. Generation of the second yaw moment YM2 is performed simultaneously. Thereby, it can prevent more reliably that a roll generate | occur | produces in a vehicle. Here, in order to generate yaw moments in opposite directions on the front wheel side and rear wheel side, or on the right wheel side and left wheel side, if roll moments in opposite directions are generated, Force (load) is applied. If the first yaw moment YM1 and the second yaw moment YM2 are generated simultaneously as in the first to third embodiments, the force in the twist direction increases.

  On the other hand, in the vehicle control apparatus 1 according to the present embodiment, the yaw rate control unit 104 generates the first yaw moment YM1 due to the generation of the roll moment toward the side with the larger braking force distribution and moves toward the side with the smaller braking force distribution. The generation of the second yaw moment YM2 by the generation of the roll moment is alternately performed. As a result, the roll moment generated on the larger braking force distribution side and the roll moment generated on the smaller braking force distribution side cancel each other to stabilize the vehicle roll posture, and the first yaw moment YM1 and the second yaw moment Compared with the case where the moment YM2 is generated simultaneously, the force in the twisting direction applied to the vehicle body can be reduced. Here, the “alternate” means a state in which the timings at which the yaw rate control unit 104 transmits control signals to the front wheel side and rear wheel side or right wheel side and left wheel side actuators 30 do not overlap.

  The present invention is not limited to the above-described embodiments, and the embodiments can be combined, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. Embodiments added or modified are also included in the scope of the present invention. Each of the above-described embodiments and a new embodiment resulting from the combination of each of the above-described embodiments and the following modified examples have the effects of the combined embodiments and modified examples.

  In the vehicle control device 1 according to each of the embodiments described above, the active stabilizer device 10 is used as the ground load adjustment unit. For example, a suspension device including an air spring capable of adjusting the elastic force is used as the ground load adjustment unit. It may be used. When such a suspension device is used, the ground contact load of the left and right wheels can be made different by changing the elastic force of the air spring of each wheel.

  In each of the above-described embodiments, yaw rate adjustment control is performed when the actual yaw rate Yo deviates from the target yaw rate Yt due to the bias yaw moment YMb generated according to the bias of the center of gravity position of the vehicle. However, the cause that the actual yaw rate Yo deviates from the target yaw rate Yt is not limited to the deviation of the center of gravity position of the vehicle. Even when the actual yaw rate Yo deviates from the target yaw rate Yt due to other factors, the yaw rate adjustment in each of the above-described embodiments By performing the control, the actual yaw rate Yo can be made closer to the target yaw rate Yt, and the vehicle stability can be improved.

  DESCRIPTION OF SYMBOLS 1 Vehicle control apparatus, 10 Active stabilizer apparatus, 20 Stabilizer bar, 30 Actuator, 100 ECU, 102 Target yaw rate setting part, 104 Yaw rate control part, 106 Actual yaw rate estimation part, 110 Yaw rate sensor, YM1 1st yaw moment, YM2 2nd Yaw moment, YMa Yaw moment for adjustment, YMb Unbalanced yaw moment.

Claims (8)

A grounding load adjusting unit for making the grounding load of the front and rear wheels different between the left and right wheels;
A target yaw rate setting unit for setting a target yaw rate to be generated in the vehicle;
A yaw rate control unit for controlling the ground load adjustment unit to adjust the actual yaw rate generated in the vehicle;
With
The yaw rate control unit varies the ground load on the left and right wheels of the front wheel and the rear wheel during braking, and the first yaw moment is set on the side of the front wheel and the rear wheel where the braking force distribution is large, and the side of the braking force distribution is small. A vehicle control device that generates a second yaw moment in a direction opposite to the first yaw moment, and causes the actual yaw rate to approach the target yaw rate by the first yaw moment and the second yaw moment.   The vehicle control device according to claim 1, wherein the yaw rate control unit simultaneously generates the first yaw moment and the second yaw moment.   The vehicle control device according to claim 1, wherein the yaw rate control unit alternately generates the first yaw moment and the second yaw moment.   4. The vehicle control device according to claim 1, wherein the actual yaw rate includes a yaw rate caused by a biased yaw moment generated according to a bias of a center of gravity position of the vehicle.   The ground load adjustment unit includes a stabilizer having a stabilizer bar for causing a reaction force according to a twist amount to act on a front wheel side axle and a rear wheel side axle, and an actuator for changing the twist amount of the stabilizer bar. The vehicle control device according to any one of claims 1 to 4.   6. The stabilizer bar includes a bar that extends in a vehicle width direction of the vehicle and that has an end portion to which left and right front wheels are connected, and a bar that extends in the vehicle width direction of the vehicle and has an end portion to which left and right rear wheels are connected. The vehicle control device described in 1.   The stabilizer bar includes a bar extending in the front-rear direction of the vehicle and connected to the right front wheel and the right rear wheel at an end, and a bar extending in the front-rear direction of the vehicle and connected to the left front wheel and the left rear wheel. The vehicle control device according to claim 5.   When braking, the ground load on the left and right wheels of the front and rear wheels is made different so that the first yaw moment is opposite to the first yaw moment on the side with the larger braking force distribution and the first yaw moment on the side with the smaller braking force distribution. A vehicle control method comprising: generating a second yaw moment in a direction, and causing a first yaw moment and a second yaw moment to approximate an actual yaw rate generated in the vehicle to a target yaw rate to be generated in the vehicle.

Images