JP2007161143A - Vehicle stabilization controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly end vehicle stabilization control in a vehicle stabilization controller using a yaw rate to be searched by using a wheel speed as the start conditions of vehicle stabilization control. <P>SOLUTION: A second yaw rate(driving wheel yaw rate) searched based on the difference of the wheel speed of a driving wheel and a target yaw rate searched based on a steering angle and a speed are used for deciding the start conditions of vehicle stabilization control, and a first yaw rate searched from the detection signal of a yaw rate sensor 7b and the target yaw rate searched based on the steering angle and the speed are used for deciding the end conditions of vehicle stabilization control. That is, a parameter searched by using the wheel speed is used for deciding the start conditions of the vehicle stabilization control, and a parameter searched without using the wheel speed is used for deciding the end conditions of the vehicle stabilization control. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle stabilization control device that obtains stability such as a rollover tendency of a vehicle using wheel speeds and performs vehicle motion control based on the stability.

  2. Description of the Related Art Conventionally, there is a vehicle stabilization control device that obtains stability such as a rollover tendency of a vehicle by using wheel speeds and executes vehicle stabilization control such as ESC (Electronic Stability Control) based on this. Proposed.

  For example, Patent Document 1 discloses an apparatus that determines the stability of a vehicle by detecting a tendency of idling of a turning inner wheel based on a wheel speed difference between turning inner and outer wheels of a driving wheel. Patent Document 2 discloses a wheel of front and rear wheels. An apparatus for determining the stability of a vehicle from a speed difference is shown.

  However, if the stability of the vehicle is determined based solely on the idling tendency as disclosed in Patent Document 1, the steering state of the driver may not be known, and the vehicle behavior desired by the driver may not be achieved. Even if the stability of the vehicle is determined based on the wheel speed difference between the front and rear wheels as disclosed in Patent Document 2, the same problem occurs.

  Therefore, prior to the present application, the present inventors obtain the second yaw rate (drive wheel yaw rate) from the wheel speeds of the left and right drive wheels, and obtain the target yaw rate from the steering angle and the vehicle speed indicating the steering state of the driver, A vehicle stabilization control device has been filed for obtaining a skid tendency from these differences or a differential value of the difference and executing ESC based on the result (see Japanese Patent Application No. 2005-351878).

Thus, by obtaining the yaw rate, that is, the drive wheel yaw rate from the wheel speeds of the left and right drive wheels, the parameters used for the vehicle stabilization control can be obtained with good responsiveness, and the vehicle stabilization control with good responsiveness can be performed. Etc. are obtained.
Japanese Patent No. 3547956 JP 2001-106050 A

  However, when the vehicle stability is determined using the wheel speed as in the vehicle stabilization control device previously proposed by the present inventors or the conventional vehicle stabilization control device, the vehicle stabilization control is started. There is no problem when deciding conditions, but the following problems occur when ending conditions are decided.

  That is, when executing the vehicle stabilization control, for example, the tendency of the vehicle to skid is eliminated by applying a braking force to the wheel to be controlled or controlling the driving force for the driving wheel. And, for example, in the case of the vehicle stabilization control device previously proposed by the present inventors, when the start condition is satisfied when the difference between the drive wheel yaw rate and the target yaw rate exceeds the start threshold, the start condition is satisfied. Vehicle stabilization control is started.

  For this reason, an end condition for ending the vehicle stabilization control is also set corresponding to such a start condition. For example, it can be considered that the end condition is that the difference between the drive wheel yaw rate and the target yaw rate falls below the end threshold.

  However, if a braking force or the like is applied to the wheel to be controlled by starting the vehicle stabilization control, the wheel speed is affected thereby. That is, since a braking force or the like is applied to the wheel to be controlled, a correct wheel speed cannot be obtained. For this reason, if the end condition is determined using the parameter using the wheel speed, there is a problem that the vehicle stabilization control may not be properly ended.

  SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to enable a vehicle stabilization control to be properly terminated in a vehicle stabilization control apparatus that uses a yaw rate obtained by utilizing wheel speed as a vehicle stabilization control start condition. To do.

  In order to achieve the above object, in the first aspect of the invention, the vehicle state indicating the stability of the vehicle is obtained by the first vehicle state detection means (120, 130) using the parameters obtained based on the wheel speed. At the same time, in the second vehicle state detection means (170, 180), a vehicle state indicating the stability of the vehicle is obtained using a parameter obtained based on the wheel speed of a wheel different from the wheel to be controlled. Then, the stabilization start determination means (140) determines whether or not the vehicle state obtained by the first vehicle state detection means exceeds the vehicle stabilization control start threshold value, thereby stabilizing the vehicle. It is determined whether or not the control is to be started. When the control is to be started, the stabilization control means (150, 160) adjusts the braking force or driving force applied to the control target wheel of the vehicle stabilization control, After the start of the vehicle stabilization control, the vehicle stabilization end determination means (190) determines whether or not the vehicle state obtained by the second vehicle state detection means is below the vehicle stabilization control end threshold. Thus, it is characterized in determining whether or not to end the vehicle stabilization control.

  As described above, when determining the termination condition of the vehicle stabilization control, the vehicle state indicating the stability of the vehicle can be obtained by using the parameter obtained based on the wheel speed of the wheel different from the wheel to be controlled.

  Therefore, if the vehicle stabilization control end condition is determined using the vehicle state thus obtained, the wheel speed is affected by applying a braking force to the wheel to be controlled by the vehicle stabilization control. Even if it is received, since the end condition is not determined using the parameter using such wheel speed, the vehicle stabilization control can be appropriately ended.

  For example, as shown in claim 2, the second vehicle state detection means includes means for acquiring a first yaw rate of the vehicle based on a detection signal of a yaw rate sensor (7b) provided in the vehicle, steering in the vehicle ( 9) A steering angle is obtained based on the detection signal of the steering angle sensor (7a) that outputs a detection signal corresponding to the operation of 9), and the vehicle speed is obtained based on the wheel speed, and according to the obtained steering angle and vehicle speed. Means for obtaining the target yaw rate and means for obtaining the difference between the first yaw rate obtained based on the detection signal of the yaw rate sensor (7b) and the target yaw rate as the vehicle state can be adopted.

  Further, as shown in claim 3, not only the yaw rate sensor (7b) but also means for acquiring the first yaw rate based on the detection signal of the acceleration sensor that outputs the detection signal corresponding to the lateral acceleration of the vehicle. In addition, the vehicle state can be obtained.

  The invention according to claim 4 is characterized in that the second vehicle state detection means (170, 180) obtains a vehicle state indicating the stability of the vehicle using parameters obtained without using the wheel speed. .

  As described above, the parameter obtained using the wheel speed is used when determining the start condition of the vehicle stabilization control, and the parameter obtained without using the wheel speed is used when determining the end condition of the vehicle stabilization control. (Do not use parameters determined by using wheel speed).

  In this way, even if the wheel speed is affected by applying a braking force to the wheel to be controlled by the vehicle stabilization control, the end condition is determined using the parameter using such wheel speed. Thus, the vehicle stabilization control can be properly terminated.

  In the invention according to claim 5, the first vehicle state detection means obtains the wheel speed of the left and right drive wheels in the vehicle, and based on the difference in the wheel speed of the left and right drive wheels when the vehicle turns, the second yaw rate of the vehicle The steering angle is determined based on the detection signal of the steering angle sensor (7a) that outputs the detection signal corresponding to the operation of the steering wheel (9) in the vehicle, and based on the wheel speed. Thus, the vehicle speed is obtained, a target yaw rate corresponding to the obtained steering angle and vehicle speed is obtained, and a difference between the drive wheel yaw rate and the target yaw rate is obtained as a vehicle state.

  As described above, if the second yaw rate of the vehicle is obtained based on the difference between the wheel speeds of the left and right drive wheels and is used as the drive wheel yaw rate to determine the start condition of the vehicle stabilization control, the vehicle stability with good responsiveness is achieved. Control can be performed.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of an entire system in which a vehicle stabilization control device that realizes vehicle stabilization control in the first embodiment of the present invention is mounted. Here, the case where the vehicle stabilization control device according to an embodiment of the present invention is applied to an FR vehicle in which the engine is mounted on the front side and the rear wheel side is the driving wheel will be described. The present invention can be applied to other types of vehicles such as FF vehicles.

  As shown in FIG. 1, in the FR vehicle, the engine output (engine torque) generated by the engine 1 is transmitted to the transmission 2 and converted at a gear ratio corresponding to the gear position set by the transmission 2. After that, the driving force is transmitted to the propeller shaft 3. A driving force is applied to the rear wheels RR and RL serving as driving wheels through a drive shaft 5 connected to the propeller shaft 3 via a differential 4.

  The ESC-ECU 6 corresponds to a vehicle stabilization control device, and ESC is executed by the ESC-ECU 6 as vehicle stabilization control.

  Specifically, the ESC-ECU 6 detects the detection signals from the steering angle sensor 7a and the yaw rate sensor 7b and the detection signals from the wheel speed sensors 8FR, 8FL, 8RR, 8RL provided to the wheels FR, FL, RR, RL. To obtain various physical quantities. For example, the ESC-ECU 6 determines the steering angle based on a detection signal corresponding to the operation amount of the steering wheel 9 by the driver output from the steering angle sensor 7a, or actually detects the vehicle based on the detection signal output from the yaw rate sensor 7b. The generated yaw rate is obtained, or the wheel speed and vehicle speed (estimated vehicle speed) of each wheel FR, FL, RR, RL are obtained based on detection signals from the wheel speed sensors 8FR, 8FL, 8RR, 8RL.

  Further, the ESC-ECU 6 is configured to output an ESC command signal to the brake fluid pressure control actuator 10 in order to perform ESC. The ESC executed by the ESC-ECU 6 obtains the target yaw rate from the steering angle and the vehicle speed, and obtains the second yaw rate from the wheel speed difference between the driving wheels inside and outside the turn at the time of turning, and the vehicle can skid based on these. The skid tendency of whether or not the situation is determined is determined. If the skid is in a skidable situation, the wheel to be controlled is determined according to the skid form, and the skid is prevented by applying braking force to stabilize the vehicle. Is. The ESC is terminated based on the target yaw rate obtained from the steering angle and the vehicle speed and the first yaw rate obtained from the detection signal of the yaw rate sensor 7b. The ESC is terminated if it is not in a situation to obtain.

  In this embodiment, whether or not the vehicle can skid before starting ESC is determined based on the yaw rate required to follow the ideal trajectory obtained from the steering angle and the vehicle speed, that is, the trajectory in the case of no skidding. It is determined by whether or not the absolute value of the difference between the second yaw rate obtained from the wheel speed difference between the driving wheel inside and outside the turn exceeds the predetermined start threshold value. At this time, the target yaw rate is compared with the second yaw rate, and it is determined whether the vehicle is in the oversteer (OS) state or the understeer (US) state depending on which is larger, so that the wheel to be controlled according to the vehicle state Is set, and a skid is avoided by applying a braking force to the wheel to be controlled.

  Specifically, in the oversteer state, a braking force is applied with the turning outer wheel as the control target wheel, and in the understeer state, the turning inner wheel is set as the control target wheel. At this time, whether the front wheel or the rear wheel of the turning outer wheel or the turning inner wheel is to be controlled is determined by the size of the second yaw rate, the size of the rudder angle, or the size of the rudder angular velocity. It has become.

  On the other hand, after the start of ESC, whether or not it is no longer possible to skid is determined whether the absolute value of the difference between the target yaw rate obtained from the steering angle and the vehicle speed and the first yaw rate obtained from the detection signal of the yaw rate sensor 7a is a predetermined end. Judgment is made based on whether or not the threshold value is exceeded. That is, the second yaw rate used for the determination of the start condition and the first yaw rate used for the determination of the end condition are the yaw rates obtained by different calculation methods.

  The brake fluid pressure control actuator 10 is configured as a brake system that can automatically pressurize wheel cylinders (hereinafter referred to as W / C) 11FR, 11FL, 11RR, and 11RL. As the brake fluid pressure control actuator 10, either a hydraulic brake system that generates W / C pressure by hydraulic pressure or an electric brake system such as a brake-by-wire that generates W / C pressure electrically can be adopted. Therefore, the specific structure of the brake fluid pressure control actuator 10 is omitted here.

  The brake fluid pressure control actuator 10 pressurizes the W / C 11FR to 11RL corresponding to the wheel to be controlled, thereby causing the disc rotors 13FR, 13FL, 13RR, and calipers 12FR, 12FL, 12RR, and 12RL. A braking force is generated when 13RL is sandwiched. The brake fluid pressure control actuator 10, W / C 11 FR to 11 RL, caliper 12 FR to 12 RL, and disc rotor 13 FR to 13 RL shown here are for generating a braking force, and the vehicle stabilization control referred to in the present invention. The braking force generated on the wheel to be controlled in the vehicle stabilization control is adjusted by being controlled by the means.

  Thus, the system provided with the vehicle stabilization control apparatus which implement | achieves vehicle stabilization control is comprised. Next, vehicle stabilization control performed by the vehicle stabilization control device of the present embodiment will be described with reference to FIG.

  FIG. 2 is a flowchart of the vehicle stabilization control, which is executed by the ESC-ECU 6. This vehicle stabilization control is executed every predetermined calculation cycle when an ignition switch (not shown) provided in the vehicle is turned on or during vehicle travel. The steps shown in the figure correspond to means for executing various processes.

  First, in step 100, processing for reading various sensor signals is performed. Specifically, various detection signals necessary for vehicle stabilization control, such as detection signals of the wheel speed sensors 8FL to 8RR and detection signals of the steering angle sensor 7a and the yaw rate sensor 7b, are read, and each physical value is obtained from them. It is done. As a result, the wheel speed and the vehicle speed (estimated vehicle body speed) of each of the wheels FL to RR and the steering angle corresponding to the operation of the steering 9 by the driver are obtained.

  Next, in step 110, it is determined whether vehicle stabilization control is being performed. For example, whether or not the vehicle stabilization control is being performed is determined based on whether or not the vehicle stabilization control in-progress flag set in step 130 described later is set.

  In the following step 120, the yaw rate actually generated for the vehicle at this time, that is, the second yaw rate used for the determination of the start condition is obtained from the difference between the wheel speeds of the left and right rear wheels RL and RR serving as driving wheels. . The second yaw rate at this time corresponds to the drive wheel yaw rate in the present invention.

  For example, when the wheel speeds of the left and right rear wheels RL and RR are represented as VwRL and VwRR, and the distance (tread) between the left and right rear wheels RL and RR is represented by r, the second yaw rate is represented by the following equation.

(Equation 1)
Second yaw rate = (VwRR−VwRL) / r
Note that the difference between the wheel speeds VwRL and VwRR of the left and right rear wheels RL and RR varies depending on whether the vehicle is turning right or turning left. For example, in the case of a left turn, the wheel speed VwRL of the left rear wheel RL is smaller than the wheel speed VwRR of the right rear wheel RR, and vice versa in the case of a right turn. This difference also changes depending on the idling state of the turning inner wheel. That is, when the turning inner wheel is idling, the wheel speed includes the idling amount, so the second yaw rate is obtained as a value including the idling amount of the turning inner wheel.

  In step 130, a target yaw rate is calculated. Specifically, the target yaw rate is estimated by a known method from the steering angle and vehicle speed obtained based on the detection signal of the steering angle sensor 7a. Although the vehicle speed used at this time is calculated | required using wheel speed VwFR-VwRL of each wheel FR-RL, any vehicle speed VwFR-VwRL may be used and a vehicle speed may be calculated | required. Then, the absolute value of the difference between the second yaw rate indicated by the drive wheel yaw rate obtained in step 120 and the target yaw rate obtained in step 130 is obtained. This difference indicates a skid tendency, that is, a vehicle state. The part of the ESC-ECU 6 that executes this process corresponds to the first vehicle state detection means.

  Thereafter, the routine proceeds to step 140, where it is determined whether or not the vehicle state exceeds a start threshold value. That is, when the vehicle state exceeds the start threshold value, it is assumed that a skid tendency has occurred in the vehicle, such as a situation where the turning inner wheel is idling.

  For this reason, when a negative determination is made in step 140, it is considered that a skid tendency has not occurred, so the processing is ended as it is. If the determination in step 140 is affirmative, it is considered that a skid tendency has occurred. At the same time, since ESC is started as vehicle stabilization control, a vehicle stabilization control flag indicating this is set. A portion of the ESC-ECU 6 that executes this process corresponds to a stabilization start determination unit.

  In step 150, the control amount is calculated. The calculation of the control amount here means a control amount corresponding to a braking force to be generated for the wheel to be controlled in order to eliminate a skid tendency generated in the vehicle, that is, in order to generate such a braking force. The current value, control time, and the like of how to drive a control valve and a motor provided in the brake fluid pressure control actuator 10 are obtained. This control amount is obtained based on the magnitude of the difference between the second yaw rate and the target yaw rate.

  Then, the process proceeds to step 160, and actuator drive processing is executed. The actuator driving process here is to generate a braking force on the wheel to be controlled by ESC, and to output an ESC command signal to the brake fluid pressure control actuator 10. As a result, the brake fluid pressure control actuator 10 automatically pressurizes the W / C 11FR to 11RL corresponding to the wheel to be controlled, whereby the disc rotors 13FR to 13RL are sandwiched by the calipers 12FR to 12RL, and a braking force is generated. It is like that.

  For example, when the idling of the turning inner wheel is suppressed as in this embodiment, the wheel to be controlled becomes the driving wheel on the turning inner wheel side, and the corresponding W / C 11 RR and 11 RL are automatically pressurized.

  In this way, by suppressing idling of the driving wheel on the turning inner wheel side, it becomes possible to suppress the load fluctuation of the vehicle, so it is possible to suppress the occurrence of the roll angle of the vehicle, and at the same time, the turning inner wheel side. Understeer due to idling (wheel floating) can be suppressed.

  In addition, the part that executes the vehicle stabilization control that suppresses the idling of the driving wheel on the turning inner wheel side, that is, the part that executes the processing of steps 150 and 160 in the ESC-ECU 6 corresponds to the stabilization control means. To do.

  Thus, when ESC is started as vehicle stabilization control, the processing is repeated from step 100 again. Then, after the signal reading process is performed in step 100, the process proceeds to step 110. Since vehicle stabilization control is now being performed, an affirmative determination is made at step 110 and the routine proceeds to step 170.

  In step 170, the first yaw rate is obtained from the detection signal of the yaw rate sensor 7b. Since the yaw rate sensor 7b here generates a signal proportional to the angular velocity of the vehicle, the detection signal is not related to the wheel speed. Therefore, the first yaw rate obtained from the detection signal of the yaw rate sensor 7b is not affected by the change in the wheel speed.

  Subsequently, the process proceeds to step 180, and the target yaw rate is obtained from the steering angle and the vehicle speed based on the detection signal of the steering angle sensor 7a as in step 130 described above. The vehicle speed used at this time is obtained using the wheel speeds VwRL to VwRR of the respective wheels FR to RL, but the vehicle speed is obtained using only the wheel speeds VwRL to VwRR of the wheels FR to RL different from the wheel to be controlled. Yes. Then, the absolute value of the difference between the first yaw rate based on the detection signal of the yaw rate sensor 7b obtained in step 170 and the target yaw rate obtained in step 180 is obtained. This difference indicates the vehicle state. A portion of the ESC-ECU 6 that executes this process corresponds to second vehicle state detection means.

  Then, it progresses to step 190 and it is determined whether the vehicle state has exceeded the completion | finish threshold value. Specifically, it is determined whether or not the vehicle state is below the end threshold value. The portion of the ESC-ECU 6 that executes this process corresponds to the stabilization end determination means.

  That is, when the vehicle state falls below the end threshold, it is assumed that the vehicle has no tendency to skid. For this reason, if a negative determination is made in step 190, it is considered that a skid tendency is still occurring. Therefore, the process proceeds to step 150 and the same processing as described above is repeated. When the skid tendency is eliminated, the process is terminated and the vehicle stabilization control flag is reset.

  As described above, in the present embodiment, the vehicle stabilization control start condition is determined based on the second yaw rate (drive wheel yaw rate), the steering angle, and the vehicle speed obtained based on the difference in the wheel speeds of the drive wheels. The target yaw rate obtained based on this is used. The vehicle stabilization control end condition is determined using the first yaw rate obtained from the detection signal of the yaw rate sensor 7b, the target yaw rate obtained based on the steering angle and the vehicle speed.

  That is, when determining the start condition of the vehicle stabilization control, the parameter obtained using the wheel speed is used, and when determining the end condition of the vehicle stabilization control, the wheel speed of a wheel different from the control target wheel is used. The required parameters are used.

  In this way, even if the wheel speed is affected by applying a braking force to the wheel to be controlled by the vehicle stabilization control, the end condition is determined using the parameter using such wheel speed. Thus, the vehicle stabilization control can be properly terminated.

  Although it is conceivable that the parameters obtained by using the wheel speed are not used for both the determination of the start condition and the end condition of the vehicle stabilization control, the vehicle stabilization control is not performed as in this embodiment. The following effects can be obtained by using the second yaw rate (drive wheel yaw rate) obtained based on the difference between the wheel speeds of the drive wheels in the determination of the start condition.

  When the driver turns the vehicle by operating the steering 9, first, the operation of the steering 9 by the driver appears as a steering angle, and at the same time, the steering angles of both front wheels FR and FL that become steering wheels change. Then, the vehicle turns due to the change of the steering angle, and the load moves to the turning outer wheel side, so that the driving wheel on the turning inner wheel side becomes idle. Therefore, the idling amount of the driving wheel appears as a wheel speed, and appears as a second yaw rate (driving wheel yaw rate) obtained based on the difference in wheel speed of the driving wheel.

  When the idling of the turning inner wheel occurs, the behavior of the vehicle changes due to the idling. Since such a change appears as yaw by the yaw rate sensor, when the first yaw rate is obtained based on the detection result of the yaw rate sensor, it is obtained at this timing. Further, since this also appears in the lateral acceleration, when the first yaw rate is obtained from the lateral acceleration, it is obtained at this timing.

  In this way, when obtaining the yaw rate, it can be seen that the time required for obtaining the yaw rate after the driver operates, that is, the responsiveness differs depending on the method of obtaining the yaw rate. Specifically, the response is delayed in the order of a method of obtaining from a steering angle, a method of obtaining from a difference in wheel speeds of driving wheels, a method of obtaining from a detection result of a yaw rate sensor, and a method of obtaining from a lateral acceleration. This difference in responsiveness is caused by the difference between the steering angle and the wheel speed of the drive wheels, which causes the yaw rate, while the yaw and lateral acceleration detected by the yaw rate sensor are the causes. This occurs because the physical quantity actually generated is detected.

  On the other hand, in this embodiment, the second yaw rate (drive wheel yaw rate) is obtained based on the difference in the wheel speeds of the drive wheels, and the target yaw rate is obtained from the steering angle and the vehicle speed. That is, the second yaw rate and the target yaw rate are obtained using a factor that generates the yaw rate, in other words, a fast response. For this reason, it is possible to obtain the target yaw rate and the second yaw rate with good responsiveness, and when performing ESC based on them, it is possible to perform ESC with good responsiveness.

(Other embodiments)
In the above embodiment, the end condition setting method for the vehicle stabilization control device previously filed by the present inventors has been described. However, the wheel speed is used to obtain a parameter for determining the vehicle stability. The present invention can also be applied to this. For example, as described in the background section above, the stability of the vehicle can be determined by detecting the tendency of idling of the turning inner wheel based on the wheel speed difference between the turning inner and outer wheels of the driving wheel, The present invention can also be applied to a vehicle stabilization control device that determines the stability of a vehicle from the difference.

  In the above embodiment, an example of using a parameter obtained by using a wheel speed of a non-control target wheel that is not a control target wheel of the vehicle stabilization control is used as a parameter used to determine a vehicle stabilization control end condition. However, even if the end condition is determined without using the parameters obtained by using the wheel speed, the same effect as in the above embodiment can be obtained. For example, it is also possible to obtain the vehicle state (for example, the difference between them) based only on the detection signal of the yaw rate sensor 7b or the lateral acceleration sensor, and to determine the vehicle stabilization control end condition based on this. is there. In this case, it is only necessary to obtain a parameter that does not use the wheel speed in step 170 described above, and the processing in each of the other steps is exactly the same as in FIG.

  Further, in the above embodiment, the first yaw rate obtained from the detection signal of the yaw rate sensor 7b is used as the parameter used for determining the end condition of the vehicle stabilization control. However, other parameters may be used. Absent. For example, the lateral acceleration (lateral G) of the vehicle may be obtained from a detection signal of an acceleration sensor that generates a detection signal corresponding to the lateral G, for example, and the obtained lateral G may be used for determining the end condition. In this case, when the lateral G falls below the level set as the end threshold value, it can be determined that the vehicle has stabilized, and the vehicle stabilization control can be ended.

  In the above embodiment, the stability of the vehicle is obtained based on the difference between the target yaw rate obtained from the steering angle and the vehicle speed and the second yaw rate obtained from the wheel speed difference between the turning inner and outer wheels of the driving wheel. The rollover tendency of the vehicle can also be obtained based on a differential value obtained by time-differentiating this difference. In this way, since the differential value of the difference between the target yaw rate and the second yaw rate has a phase earlier than the simple difference, the responsiveness can be further improved.

  In the above embodiment, detection signals from the steering angle sensor 7a, the yaw rate 7b, and the wheel speed sensors 8FR to 8RL are input to the ESC-ECU 6, and the ESC-ECU 6 calculates the steering angle, yaw rate, wheel speed, vehicle speed, and the like. I have to. However, this is merely an example, and detection signals from the steering angle sensor 7a, the yaw rate sensor 7b, or the wheel speed sensors 8FR, 8FL, 8RR, and 8RL are input to another ECU (not shown). Thus, various physical quantities may be obtained and transmitted to the ESC-ECU 6 through an in-vehicle LAN or the like.

  Furthermore, in the above embodiment, the vehicle stabilization control is shown in which the braking force is generated with respect to the wheel to be controlled so as to suppress the idling of the turning inner wheel, but other control modes may be used. For example, a braking force may be generated on the wheel to be controlled so that the second yaw rate approaches the target yaw rate.

  The steps shown in each figure correspond to means for executing various processes.

It is the figure which showed the whole system configuration | structure of the vehicle stabilization control apparatus in 1st Embodiment of this invention. It is a flowchart of vehicle stabilization control.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Transmission, 3 ... Propeller shaft, 4 ... Differential, 5 ... Drive shaft, 6 ... ESC-ECU, 7a ... Steering angle sensor, 7b ... Yaw rate sensor, 8FL-8RR ... Wheel speed sensor, 9 ... Steering DESCRIPTION OF SYMBOLS 10 ... Actuator for brake hydraulic pressure control, 11FR-11RR ... W / C, 12FR-12RR ... Caliper, 13FR-13RR ... Disc rotor, FL-RR ... Wheel.

Claims (5)

First vehicle state detection means (120, 130) for determining a vehicle state indicating the stability of the vehicle using a parameter determined based on the wheel speed;
The stability for determining whether to start the vehicle stabilization control by determining whether the vehicle state obtained by the first vehicle state detection means exceeds the start threshold value of the vehicle stabilization control. Start determination means (140),
Stabilization control means (150, 160) for adjusting a braking force or a driving force applied to the control target wheel of the vehicle stabilization control based on a determination result in the stabilization start determination means (140);
Second vehicle state detection means (170, 180) for determining a vehicle state indicating the stability of the vehicle using a parameter determined based on the wheel speed of a wheel different from the wheel to be controlled;
It is determined whether or not to end the vehicle stabilization control by determining whether or not the vehicle state obtained by the second vehicle state detection means is below an end threshold value of the vehicle stabilization control. And a vehicle stabilization control unit (190) for performing the vehicle stabilization control. The second vehicle state detecting means is
Means for obtaining a first yaw rate of the vehicle based on a detection signal of a yaw rate sensor (7b) provided in the vehicle;
The steering angle is obtained based on the detection signal of the steering angle sensor (7a) that outputs a detection signal corresponding to the operation of the steering (9) in the vehicle, the vehicle speed is obtained based on the wheel speed, and the obtained steering angle is obtained. And a means for obtaining a target yaw rate according to the vehicle speed;
The means for obtaining a difference between the first yaw rate obtained based on a detection signal of the yaw rate sensor (7b) and the target yaw rate as the vehicle state. Vehicle stabilization control device. The second vehicle state detecting means is
Means for obtaining a first yaw rate of the vehicle based on the detection signal of an acceleration sensor that outputs a detection signal corresponding to a lateral acceleration of the vehicle provided in the vehicle;
The steering angle is obtained based on the detection signal of the steering angle sensor (7a) that outputs a detection signal corresponding to the operation of the steering (9) in the vehicle, the vehicle speed is obtained based on the wheel speed, and the obtained steering angle is obtained. And a means for obtaining a target yaw rate according to the vehicle speed;
2. The vehicle stabilization according to claim 1, further comprising a unit that obtains a difference between the first yaw rate obtained based on a detection signal of the acceleration sensor and the target yaw rate as the vehicle state. Control device. First vehicle state detection means (120, 130) for determining a vehicle state indicating the stability of the vehicle using a parameter determined based on the wheel speed;
It is determined whether or not the vehicle stabilization control is to be started by determining whether or not the vehicle state obtained by the first vehicle state detection means exceeds a vehicle stabilization control start threshold value. Stabilization start determination means (140);
Stabilization control means (150, 160) for adjusting a braking force or a driving force applied to the control target wheel of the vehicle stabilization control based on a determination result in the stabilization start determination means (140);
Second vehicle state detection means (170, 180) for determining a vehicle state indicating the stability of the vehicle using parameters determined without using the wheel speed;
It is determined whether or not to end the vehicle stabilization control by determining whether or not the vehicle state obtained by the second vehicle state detection means is below an end threshold value of the vehicle stabilization control. And a vehicle stabilization control unit (190) for performing the vehicle stabilization control. The first vehicle state detection means includes
Means for obtaining wheel speeds of left and right drive wheels in the vehicle, and obtaining a drive wheel yaw rate that is a second yaw rate of the vehicle based on a difference in wheel speeds of the left and right drive wheels when the vehicle is turning;
The steering angle is obtained based on the detection signal of the steering angle sensor (7a) that outputs a detection signal corresponding to the operation of the steering (9) in the vehicle, the vehicle speed is obtained based on the wheel speed, and the obtained steering angle is obtained. And a means for obtaining a target yaw rate according to the vehicle speed;
5. The vehicle stabilization control device according to claim 1, further comprising means for obtaining a difference between the drive wheel yaw rate and the target yaw rate as the vehicle state.

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