JP2005206005A - Vehicle behavior control device with lateral acceleration sensor and yaw rate sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent unnecessary stop of behavior control in a state allowing the execution of the behavior control while effectively reducing the possibility of improper execution of the behavior control based on a detection value of a lateral acceleration sensor or a yaw rate sensor under abnormal conditions of those sensors. <P>SOLUTION: An index value ΔYr indicating the degree of behavioral deterioration is calculated as a value including Yr+KhGyV (S30). When the index value ΔYr is at a reference value Yro or more, and the behavioral deterioration of the vehicle is determined (S40), control for stabilizing the vehicle behavior is executed (S50-80). The reference value Yro is set at a standard value Yro1 when the average value ¾Acc¾/CTo of the absolute value of the integrated value Acc of Yr+KhGyV throughout a CTo cycle during a straight running state of the vehicle is at a reference value Th1 or less. When the average value ¾Acc¾/CTo is at the reference value Th1 or more, it is set at Yro2 greater than the standard value Yro1 (S120-240). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle including a lateral acceleration sensor and a yaw rate sensor, and more particularly to a vehicle behavior control apparatus that determines and controls the behavior of a vehicle based on detection results of the lateral acceleration sensor and the yaw rate sensor.

  As one of behavior control devices for vehicles such as automobiles, for example, as described in Patent Document 1 below, the reference yaw rate of the vehicle is calculated based on the vehicle speed and the steering angle, and the deviation between the reference yaw rate and the detected yaw rate is large. Is a behavior control device that controls the behavior of the vehicle by controlling the braking force of each wheel when the vehicle speed exceeds the reference value, and calculates the estimated yaw rate as a value obtained by dividing the lateral acceleration of the vehicle by the vehicle speed. The yaw rate sensor is determined to be abnormal and the behavior control is stopped when the deviation between the detected yaw rate and the estimated yaw rate when the vehicle is running straight is greater than a predetermined value. 2. Description of the Related Art Vehicle behavior control devices are conventionally known.

According to the conventional behavior control device described in Patent Document 1 described above, when the yaw rate sensor is abnormal, it is determined, and behavior control is performed inappropriately based on the detected value of the abnormal yaw rate sensor. This can be surely prevented.
JP 10-44954 A

  However, in the conventional behavior control apparatus described in Patent Document 1 described above, the yaw rate deviation, which is an index value for the deterioration of the behavior of the vehicle, is calculated based on the yaw rate, the vehicle speed, and the steering angle of the vehicle. The abnormality determination of the yaw rate sensor is performed based on the yaw rate of the vehicle, the vehicle speed, and the lateral acceleration of the vehicle. Therefore, even when the lateral acceleration sensor that detects the lateral acceleration of the vehicle is abnormal, there is a problem that behavior control based on the yaw rate deviation that does not require the detected value of the abnormal lateral acceleration sensor is unnecessarily stopped.

  Further, in a behavior control device in which a yaw rate deviation, which is an index value for deterioration of vehicle behavior, is calculated based on the yaw rate, vehicle speed, steering angle, and lateral acceleration of the vehicle, the yaw rate sensor for detecting the yaw rate of the vehicle and the vehicle Even if an abnormality such as a zero point deviation occurs in the lateral acceleration sensor that detects the lateral acceleration, if the abnormality of these sensors is an abnormality that mutually cancels the influence on the index value of the vehicle behavior deterioration, that is, the yaw rate sensor If the index value of the vehicle behavior deterioration can be calculated without a large error even if the lateral acceleration sensor is not normal, it is preferable to continue the behavior control without stopping, but it is described in Patent Document 1 described above. The conventional behavior control apparatus cannot cope with such a situation.

  The present invention has been made in view of the above-mentioned problems in the conventional behavior control apparatus, and the main problem of the present invention is that the yaw rate deviation, which is an index value of the deterioration of the behavior of the vehicle, is the yaw rate and laterality of the vehicle. When the calculation is based on the acceleration, the lateral acceleration sensor or the yaw rate sensor sensor is determined based on the index value of the deterioration of the behavior of the vehicle when the vehicle is traveling straight, thereby determining whether the lateral acceleration sensor or the yaw rate sensor sensor is abnormal. In the situation where the yaw rate sensor sensor is abnormal, the behavior control can be performed in a situation where the behavior control may be executed while effectively reducing the possibility of inappropriate behavior control being performed based on the detected values. It is to prevent being canceled unnecessarily.

  According to the present invention, the main problem described above is that according to the configuration of the present invention, that is, with the vehicle lateral acceleration Gy detected by the lateral acceleration sensor and the yaw rate sensor sensor, where the vehicle speed is V and the vehicle stability factor is Kh. Based on the detected yaw rate Yr of the vehicle, an index value of the vehicle behavior deterioration is calculated as a value including Yr + KhGyV, and the braking / driving force of each wheel is controlled when the behavior deterioration index value is larger than the reference value. Thus, the vehicle behavior control device for controlling the behavior of the vehicle is used, and when the magnitude of Yr + KhGyV when the vehicle is in the straight traveling state is larger than the reference value for abnormality determination, the reference value for the behavior deterioration determination is set as a standard. This is achieved by a vehicle behavior control device characterized by being larger than the value.

According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1, the steering angle is θ, the steering gear ratio is N, and the vehicle wheel base is L. ,
ΔYr = Yr + KhGyV− (θ × V) / (N × L)
The behavior deterioration index value is calculated according to the above (structure of claim 2).

  Further, according to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1 or 2, the larger the magnitude of Yr + KhGyV, the larger the reference value for the behavior deterioration determination. (Constitution of Claim 3)

In general, according to the vehicle model, when the stability factor is Kh, the vehicle speed is V, the steering angle is θ, the steering gear ratio is N, and the vehicle wheelbase is L, the vehicle yaw rate Yr is expressed by the following equation: Represented by 1.
Yr = {1 / (1 + Kh × V × V)} × (θ × V) / (N × L) (1)

  When (1 + Kh × V × V) is applied to both sides of the above formula 1, the following formula 2 is obtained. When the lateral acceleration of the vehicle is Gy, the following formula 3 is obtained from the relationship of Gy = Yr × V. Therefore, based on the vehicle speed V, the steering angle θ, and the lateral acceleration Gy of the vehicle, the reference yaw rate Yrt of the vehicle can be calculated according to the following equation 4.

Yr + Kh × (Yr × V) × V = (θ × V) / (N × L) (2)
Yr = (θ × V) / (N × L) −Kh × Gy × V (3)
Yrt = (θ × V) / (N × L) −Kh × Gy × V (4)

Therefore, the deviation ΔYr between the vehicle yaw rate Yr and the reference yaw rate Yrt is expressed by the following equation 5, and it can be understood that the behavior deterioration index value ΔYr can be calculated as a value including Yr + KhGyV.
ΔYr = Yr− (θ × V) / (N × 1) −Kh × Gy × V
= Yr + KhGyV- (θ × V) / (N × L) (5)

  If the yaw rate sensor for detecting the yaw rate Yr of the vehicle and the lateral acceleration sensor for detecting the lateral acceleration Gy of the vehicle are normal, the deviation ΔYr between the yaw rate Yr and the reference yaw rate Yrt when the vehicle is running straight is substantially Therefore, it can be determined that the yaw rate sensor or the lateral acceleration sensor is abnormal when the yaw rate deviation ΔYr is large when the vehicle is traveling straight.

  In particular, when the vehicle is running straight, the steering angle θ is 0. However, even if the steering angle sensor that detects the steering angle θ is normal, the steering wheel is misaligned or the road surface friction coefficient is extremely high. Since the detected value of the steering angle θ may become a certain value during acceleration in a very low situation, whether or not the magnitude of Yr + KhGyV excluding the term including the steering angle θ in Equation 5 is large. Thus, it can be determined whether the yaw rate sensor or the lateral acceleration sensor is abnormal.

  According to the configuration of the first aspect, when the magnitude of Yr + KhGyV when the vehicle is in the straight traveling state is larger than the reference value for abnormality determination, the reference value for behavior deterioration determination is made larger than the standard value. When an abnormality occurs in the yaw rate sensor or lateral acceleration sensor, this can be determined reliably, and there is an effect that inappropriate behavior control may be performed based on the detected value of the abnormal yaw rate sensor or lateral acceleration sensor. Can be reduced.

  Further, according to the configuration of the first aspect, an abnormality occurs in the yaw rate sensor and the lateral acceleration sensor, and the yaw rate Yr and the lateral acceleration Gy detected by the two sensors are inaccurate values different from the actual values of the vehicle. Even if there is an abnormality in the sensors, the influence of the deterioration in the behavior of the vehicle on the index value is mutually canceled. The magnitude of Yr + KhGyV is equal to or less than the reference value for the abnormality determination, and the vehicle behavior including the value of Yr + KhGyV. When the deterioration index value can be calculated accurately, the behavior control of the vehicle is executed with the reference value for the behavior deterioration determination set to the standard value, so the yaw rate sensor and lateral acceleration sensor malfunction. Regardless of this, the behavior of the vehicle can be effectively stabilized.

According to the configuration of claim 2, the steering angle is θ, the steering gear ratio is N, the vehicle wheelbase is L,
ΔYr = Yr + KhGyV− (θ × V) / (N × L)
Accordingly, the behavior deterioration index value is calculated according to the above, and therefore it is possible to accurately determine whether or not the vehicle behavior has deteriorated based on the behavior deterioration index value ΔYr.

  According to the third aspect of the present invention, the larger the magnitude of Yr + KhGyV is, the larger the reference value for determination of behavior deterioration is. Therefore, the magnitude of Yr + KhGyV is larger and the degree of abnormality of the yaw rate sensor or lateral acceleration sensor is higher. As the reference value of the behavior deterioration determination is increased and the risk of performing appropriate behavior control due to the abnormality of the sensor is higher, the risk of inappropriate behavior control being performed can be reduced.

[Preferred embodiment of problem solving means]
According to one preferable aspect of the present invention, in the configuration of the first to third aspects, the average value of Yr + KhGyV over a predetermined time when the vehicle is running straight is larger than the reference value. Sometimes, the reference value for the behavior deterioration determination is configured to be larger than the standard value (preferred aspect 1).

  According to another preferred aspect of the present invention, in the configuration of the above first to third aspects, the vehicle is brought into a straight traveling state based on vehicle parameters other than the yaw rate of the vehicle, the lateral acceleration of the vehicle, and the steering angle. It is configured to determine whether or not there is (preferred aspect 2).

  According to another preferable aspect of the present invention, in the configuration of the preferable aspect 2, it is configured to determine whether or not the vehicle is in a straight traveling state based on a difference between the left and right wheel speeds (preferably Aspect 3).

  According to another preferred aspect of the present invention, in the configuration of the preferred aspect 2 described above, whether or not the vehicle is in a straight traveling state based on the position change information of the vehicle by GPS (Global Positioning System). It is comprised so that it may determine (Preferable aspect 4).

  According to another preferred aspect of the present invention, in the configuration of claims 1 to 3, the magnitude of Yr + KhGyV when the vehicle is running straight is greater than the first reference value for abnormality determination. In addition, when it is less than or equal to the second reference value that is larger than the first reference value, the reference value for the behavior deterioration determination is made larger than the standard value, and the magnitude of Yr + KhGyV when the vehicle is running straight is judged to be abnormal. When the vehicle is larger than the second reference value, the vehicle behavior control by controlling the braking / driving force of each wheel is stopped (preferred aspect 5).

  According to another preferred aspect of the present invention, in the configuration of claims 1 to 3, the abnormality determination reference value is variably set according to the vehicle speed so as to decrease as the vehicle speed increases. (Preferred embodiment 6).

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing Embodiment 1 of a vehicle behavior control apparatus according to the present invention.

  In FIG. 1, 10FL and 10FR represent the left and right front wheels of the vehicle 12, respectively, and 10RL and 10RR represent the left and right rear wheels, respectively. The left and right front wheels 10FL and 10FR, which are steered wheels, are steered via tie rods 18L and 18R by a rack and pinion type power steering device 16 that is driven in response to turning of the steering wheel 14 by the driver.

  The braking force of each wheel is controlled by controlling the braking pressure of the wheel cylinders 24FR, 24FL, 24RR, 24RL by the hydraulic circuit 22 of the braking device 20. Although not shown in the drawing, the hydraulic circuit 22 includes an oil reservoir, an oil pump, various valve devices, and the like, and the braking pressure of each wheel cylinder is normally driven according to the depression operation of the brake pedal 26 by the driver. It is controlled by the master cylinder 28 and, if necessary, is controlled by the electronic control unit 30 as described later.

  Wheel speed sensors 32FR to 32RL that detect wheel speeds (rotational speeds) Vwi (i = fl, fr, rl, rr) of the corresponding wheels are provided on the wheels 10FR to 10RL, respectively. The steering column connected to the steering wheel 14 is provided with a steering angle sensor 34 for detecting the steering angle θ. The vehicle 12 detects a pressure sensor 36 for detecting the master cylinder pressure Pm, and detects the yaw rate Yr of the vehicle. A yaw rate sensor 38 and a lateral acceleration sensor 40 for detecting the lateral acceleration Gy of the vehicle are provided. The steering angle sensor 34, the yaw rate sensor 38, and the lateral acceleration sensor 40 detect the steering angle, yaw rate, and lateral acceleration, respectively, with the left turning direction of the vehicle being positive.

  As shown in the figure, a signal indicating the wheel speed Vwi detected by the wheel speed sensors 32FR to 32RL, a signal indicating the steering angle θ detected by the steering angle sensor 34, and a signal indicating the master cylinder pressure Pm detected by the pressure sensor 36. The signal indicating the vehicle yaw rate Yr detected by the yaw rate sensor 38 and the signal indicating the vehicle lateral acceleration Gy detected by the lateral acceleration sensor 40 are input to the electronic control unit 30. Although not shown in detail in the figure, the electronic control device 30 has, for example, a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other via a bidirectional common bus. Includes a microcomputer.

  The electronic control unit 30 calculates an index value ΔYr indicating the degree of behavior deterioration as a value including a deviation between the yaw rate Yr and the target yaw rate Yrt and including Yr + KhGyV according to the flowchart shown in FIG. When the absolute value of ΔYr is equal to or larger than the reference value Yro, the target braking pressure Pti (i = fl, fr, rl, rr) of each wheel for stabilizing the behavior of the vehicle according to the absolute value of the index value ΔYr The behavior stabilization control is performed by calculating and controlling the braking pressure Pi of each wheel to the target braking pressure Pti. Although not shown in the flowchart, the electronic control unit 30 determines that the braking pressure Pi of each wheel becomes the target braking pressure Pti based on the master cylinder pressure Pm when the absolute value of the index value ΔYr is less than the reference value Yro. The normal braking force control is performed to control the above.

  In particular, the electronic control unit 30 determines whether or not the average value of the absolute values of Yr + KhGyV is larger than the reference value Th1 (positive constant) when the vehicle is running straight ahead according to the flowchart shown in FIG. When the average value of the absolute value of Yr + KhGyV is equal to or less than the reference value Th1, the reference value Yro is set to the standard value Yro1 (positive constant), and the average value of the absolute value of Yr + KhGyV is larger than the reference value Th1. In some cases, the possibility that the yaw rate sensor 38 or the lateral acceleration sensor 40 is abnormal is high, so the reference value Yro is set to a positive constant Yro2 larger than the standard value Yro1.

  Next, a behavior control routine in the embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is started by closing an ignition switch not shown in the figure, and is repeatedly executed at predetermined time intervals.

  First, at step 10, a signal indicating the wheel speed Vwi of each wheel is read, and at step 30, the vehicle speed Vwi in the manner known in the art based on the wheel speed Vwi of each wheel. And an index value ΔYr indicating the degree of behavior deterioration, that is, the deviation between the vehicle yaw rate Yr and the reference yaw rate Yrt is calculated according to the above equation 5.

  In step 40, it is determined whether or not the absolute value of the index value ΔYr is greater than or equal to the behavior determination reference value Yro, that is, whether or not the vehicle behavior has deteriorated as in the spin state. When the determination is made, the process returns to Step 10, and when the determination is affirmative, the process proceeds to Step 50.

  In step 50, signYr is used as the sign of the vehicle yaw rate Yr, and the index value ΔYr, ie, the product of the deviation Yr-Yrt between the vehicle yaw rate Yr and the vehicle reference yaw rate Yrt, and signYr is a positive value. In other words, it is determined whether or not the vehicle is in a spin state in which the yaw rate of the vehicle increases in the turning direction. If an affirmative determination is made, in step 60, based on the absolute value of the index value ΔYr. When the spin control amount Sc is calculated from the map corresponding to the graph shown in FIG. 6 and a negative determination is made, in step 70, the map corresponding to the graph shown in FIG. 7 based on the absolute value of the index value ΔYr. Thus, the drift-out control amount Dc is calculated.

  In step 80, the target braking pressure Pti of each wheel is calculated based on the spin control amount Sc or the drift-out control amount Dc and the turning direction of the vehicle, and the braking pressure Pi of each wheel is set to the target braking pressure Pti. By being controlled, a braking force for stabilizing the vehicle behavior is applied to a predetermined wheel. In this case, an affirmative determination is made at step 50, and when the vehicle is in a spin state, the predetermined wheel is set as a front outer wheel, and a negative determination is made at step 50, and a predetermined wheel is set when the vehicle is in a drift-out state. The wheels are set to the left and right rear wheels.

  Next, the operation state determination and reference value setting control routine of the lateral acceleration sensor and the yaw rate sensor in the illustrated embodiment 1 will be described with reference to the flowchart shown in FIG. Note that the control according to the flowchart shown in FIG. 3 is also started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.

First, in step 110, a signal indicating the wheel speed Vwi of each wheel is read. In step 120, the vehicle tread is determined based on the difference between the wheel speeds of the left and right wheels according to the following equation 6 using Tr of the vehicle as Tr. The estimated yaw rate Yrw is calculated.
Yrw = (Vwfr−Vwfl) / Tr (6)

  In step 130, it is determined whether or not the absolute value of the estimated yaw rate Yrw is less than a reference value Yrwo (a positive constant), that is, whether or not the vehicle is substantially in a straight traveling state. When an affirmative determination is made, the count value CT of the counter is incremented by 1 at step 140. When a negative determination is made, the count value CT of the counter is reset to 0 at step 150 and Yr + KhGyV is integrated. The value Acc is reset to 0, and then the control by the routine shown in FIG. 3 is once ended.

In step 160, Accf is the integrated value of Yr + KhGyV calculated in step 240 described later, or the previous value of the integrated value Acc of Yr + KhGyV in the case where negative determination is performed in step 170 described later. The integrated value Acc of Yr + KhGyV is calculated according to the following equation (7).
Acc = Accf + Yr + KhGyV (7)

  In step 170, it is determined whether or not the count value CT of the counter is greater than or equal to a reference value CTo (a positive constant integer), that is, the straight running state of the vehicle and the calculation of the integrated value Acc of Yr + KhGyV are performed over the CTo cycle. It is determined whether or not the process has been continued, and when a negative determination is made, the control by the routine shown in FIG. 3 is once terminated, and when an affirmative determination is made, the process proceeds to step 180.

  In step 180, it is determined whether or not the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is larger than the reference value Th1 for abnormality determination. If the reference value Yro for the behavior deterioration determination is set to the standard value Yro1 and an affirmative determination is made, it is highly possible that the yaw rate sensor 38 or the lateral acceleration sensor 40 is abnormal in step 200, so the reference value Yro is the standard. A positive constant Yro2 larger than the value Yro1 is set.

  In step 250, the integrated value Acc 'is calculated as a value obtained by subtracting the Yr + KhGyV value calculated earlier than the integrated value Acc of Yr + KhGyV. Set to the previous value Accf.

  Thus, according to the first embodiment shown in the figure, in step 30, an index value ΔYr indicating the degree of behavior deterioration is calculated as a value including Yr + KhGyV based on the lateral acceleration Gy of the vehicle and the yaw rate Yr of the vehicle. It is determined whether or not the behavior of the vehicle is deteriorated by determining whether or not the index value ΔYr is equal to or greater than the reference value Yro of the behavior deterioration determination. In step 50, it is determined whether the vehicle is in a spin state or a drift-out state.

  When it is determined that the vehicle is in the spin state, the spin control amount Sc is calculated based on the absolute value of the index value ΔYr in step 60, and when it is determined that the vehicle is in the drift-out state, the process proceeds to step 70. Thus, the drift-out control amount Dc is calculated based on the absolute value of the index value ΔYr. In step 80, the braking pressure of each wheel is controlled based on the spin control amount Sc or the drift-out control amount Dc. The behavior is stabilized.

  In this case, the reference value Yro for determining the deterioration of the vehicle behavior in step 40 is the average of the absolute values of the integrated values Acc of Yr + KhGyV over the CTo cycle when the vehicle is running straight according to the flowchart shown in FIG. The value | Acc | / CTo is variably set. When the average value | Acc | / CTo is equal to or less than the abnormality determination reference value Th1, the standard value Yro1 is set, and the average value | Acc | / CTo is the abnormality determination reference value Th1. If the yaw rate sensor 38 or the lateral acceleration sensor 40 is more likely to be abnormal, the positive constant Yro2 larger than the standard value Yro1 is set.

  Therefore, according to the first embodiment shown in the figure, when an abnormality occurs in the yaw rate sensor 38 or the lateral acceleration sensor 40, and the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV becomes larger than the reference value Th1 of the abnormality determination, step 180 By making an affirmative determination in this step, it is possible to reliably determine that an abnormality has occurred in the yaw rate sensor 38 or the lateral acceleration sensor 40, and to increase the reference value Yro for determining the deterioration of vehicle behavior. Since it becomes difficult to execute the behavior stabilization control, the possibility that inappropriate behavior control is performed based on the detected value of the abnormal yaw rate sensor 38 or the lateral acceleration sensor 40 can be effectively reduced.

  Also, according to the illustrated embodiment 1, the yaw rate sensor 38 and the lateral acceleration sensor 40 are abnormal, and the yaw rate Yr and the lateral acceleration Gy detected by the two sensors are inaccurate values different from the actual values of the vehicle. Even so, these sensor abnormalities cancel each other out the influence on the vehicle behavior deterioration index value ΔYr, the magnitude of Yr + KhGyV is equal to or less than the abnormality determination reference value Th1, and includes the value of Yr + KhGyV When the vehicle behavior deterioration index value ΔYr can be calculated accurately, the vehicle behavior stabilization control is executed with the behavior deterioration determination reference value Yro set to the standard value Yro1, Regardless of the abnormality of the yaw rate sensor 38 and the lateral acceleration sensor 40, the behavior of the vehicle can be stabilized effectively.

  FIG. 4 is a flowchart showing a behavior control routine in the second embodiment of the vehicle behavior control apparatus according to the present invention, and FIG. 5 shows operation state determination and reference value setting control routine of the lateral acceleration sensor and the yaw rate sensor in the second embodiment. It is a flowchart which shows. 4 and 5, the same step numbers as those shown in FIGS. 2 and 3 are assigned to the same steps as those shown in FIGS. 2 and 3, respectively. . 4 and 5, the flag Fe relates to whether or not the yaw rate sensor 38 or the lateral acceleration sensor 40 is abnormal so that proper behavior control cannot be performed. It means that the acceleration sensor 40 is abnormal so that proper behavior control cannot be executed.

  In the behavior control routine of the second embodiment, it is determined whether or not the flag Fe is 1 at step 20 prior to step 30, that is, the yaw rate sensor 38 or the lateral acceleration sensor 40 performs appropriate behavior control. A determination is made as to whether or not the state is abnormal so that it cannot be executed. When an affirmative determination is made, the control by the routine shown in FIG. 4 is once terminated, and when a negative determination is made, the routine proceeds to step 30. The other steps are executed in the same manner as in the first embodiment.

  Although not shown in the figure, when an affirmative determination is made in step 20 during the execution of the behavior stabilization control by the braking force control, the braking pressure Pi of each wheel is prevented from changing suddenly. The braking pressure Pi is controlled to gradually become the target braking pressure Pti based on the master cylinder pressure Pm.

  In the operation state determination and reference value setting control routine routine of the second embodiment, if an affirmative determination is made in step 170, the average value of integrated values Acc of Yr + KhGyV | Acc | / It is determined whether or not CTo is greater than a second reference value Th2 for abnormality determination (a positive constant larger than the reference value Th1). If an affirmative determination is made, the flag Fe is set to 1 in step 210. When a negative determination is made, the routine proceeds to step 220.

  In step 220, the deterioration of behavior is determined based on the absolute value of the integrated value Acc of Yr + KhGyV based on the absolute value of the integrated value Acc of Yr + KhGyV so that the reference value Yro increases as the absolute value of the integrated value Acc of Yr + KhGyV increases. The reference value Yro is calculated, and in step 230, the flag Fe is reset to zero. The other steps are executed in the same manner as in the first embodiment.

  Thus, according to the illustrated second embodiment, as in the first embodiment described above, when an abnormality occurs in the yaw rate sensor 38 or the lateral acceleration sensor 40, it is reliably determined, and the abnormal yaw rate sensor 38 or lateral acceleration is detected. The possibility that inappropriate behavior control is performed based on the detection value of the sensor 40 can be effectively reduced, and the abnormality of the two sensors mutually cancels the influence of the deterioration of the vehicle behavior on the index value ΔYr. If it is abnormal, the behavior stabilization control of the vehicle is not stopped, so that the behavior of the vehicle can be effectively stabilized regardless of the abnormality of the yaw rate sensor 38 and the lateral acceleration sensor 40.

  In particular, according to the illustrated embodiment 2, when the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is larger than the second reference value Th2 for abnormality determination, the flag Fe is set to 1 in step 210. Since the affirmative determination is made in step 20, the behavior stabilization control by the control of the braking force is stopped, so that inappropriate behavior stabilization is performed based on the detected values of the abnormal yaw rate sensor 38 and the lateral acceleration sensor 40. It is possible to reliably prevent the control from being executed.

  According to the first and second embodiments shown in the drawing, whether or not the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV over the CTo cycle is larger than the reference values Th1 and Th2 for abnormality determination in steps 180 and 200. Therefore, the reference value Yro for the behavior deterioration determination is unnecessarily large as compared with the case where the determination is made whether or not the instantaneous value of Yr + KhGyV is larger than the abnormality determination reference values Th1 and Th2. Or the possibility that the vehicle behavior stabilization control will be unnecessarily stopped can be effectively reduced.

  Further, according to the first and second embodiments shown in the drawings, it is determined whether or not the vehicle is in a straight traveling state based on the estimated yaw rate Yrw of the vehicle based on the wheel speed difference between the left and right wheels. Compared with the case where the determination of whether or not the vehicle is traveling straight is based on the yaw rate Yr of the vehicle or the lateral acceleration Gy of the vehicle, the influence of the abnormality of the yaw rate sensor 38 or the lateral acceleration sensor 40 is surely eliminated. Compared to the case where the determination of whether or not the vehicle is in a straight traveling state is made based on the steering angle θ, there is a deviation in the alignment of the steering wheels or the friction coefficient of the road surface is very high. It is possible to accurately determine the straight traveling state of the vehicle even when accelerating in a low situation.

  Further, according to the first and second embodiments shown in the figure, the index value ΔYr indicating the degree of behavior deterioration is calculated as a value including the lateral acceleration Gy of the vehicle according to the above formula 5, so that the conventional technique described in the above-mentioned Patent Document 1 is used. Compared to the case where the index value of the vehicle behavior deterioration is calculated based on the yaw rate, vehicle speed, and steering angle of the vehicle as in the case of the behavior control device, the vehicle has a traveling road (bank) in which the road surface is inclined in the left-right direction. Even when traveling, it is possible to preferably execute the behavior stabilization control of the vehicle by offsetting the influence of the lateral force caused by the inclination of the road surface.

  Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in each of the above-described embodiments, whether or not the vehicle is in a straight traveling state is determined based on the estimated yaw rate Yrw of the vehicle based on the wheel speed difference between the left and right wheels. It may be performed based on the wheel speed difference itself of the wheels, or may be performed based on vehicle position change information by GPS (Global Positioning System).

  In each of the above embodiments, the estimated yaw rate Yrw of the vehicle based on the wheel speed difference between the left and right wheels is calculated based on the wheel speeds Vwfl and Vwfr of the left and right front wheels. The estimated yaw rate Yrw of the vehicle based on the speed difference may be calculated based on the wheel speeds Vwrl and Vwrr of the left and right rear wheels, and the average value of the wheel speeds Vwfl and Vwrl of the left front and rear wheels and the wheel speed Vwfr of the right front and rear wheels. The calculation may be made based on the average value of Vwrr.

  In each of the above-described embodiments, whether or not the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV over the CTo cycle is larger than the reference values Th1 and Th2 for the abnormality determination in steps 180 and 200. However, it may be modified so that it is determined whether or not a situation where the instantaneous value of Yr + KhGyV is larger than the abnormality determination reference values Th1 and Th2 continues for a predetermined time or more. .

  In each of the above-described embodiments, the abnormality determination reference value Th1 is a constant. Even if the error of the lateral acceleration Gy of the vehicle due to the abnormality of the lateral acceleration sensor is small, the higher the vehicle speed V, the more Yr + KhGyV. Since the influence of the lateral acceleration Gy of the applied vehicle is increased, the abnormality determination reference value Th1 may be variably set according to the vehicle speed V so that it decreases as the vehicle speed V increases.

  In each of the above-described embodiments, when the behavior of the vehicle is deteriorated, the behavior of the vehicle is stabilized by controlling the braking force of a predetermined wheel. May be modified to be achieved by controlling the braking and driving forces of the wheels.

  In the first embodiment, the stabilization of the vehicle behavior is not stopped even if the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is large. As in the case of the above-described second embodiment, when the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is larger than the second reference value Th2 for abnormality determination, the vehicle behavior stabilization is corrected. Also good.

  Further, in the second embodiment, the stabilization of the vehicle behavior is stopped when the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is larger than the second reference value Th2 of the abnormality determination. However, when the average value | Acc | / CTo of the integrated value Acc of Yr + KhGyV is larger than the second reference value Th2 for the abnormality determination, the stabilization of the vehicle behavior is not stopped, and the reference value for the behavior deterioration determination For example, Yro may be modified so as to be calculated as indicated by a thick broken line or an alternate long and short dash line in FIG.

It is a schematic block diagram which shows Example 1 of the vehicle behavior control apparatus by this invention. 3 is a flowchart illustrating a behavior control routine in the first embodiment. 3 is a flowchart illustrating an operation state determination and reference value setting control routine of a lateral acceleration sensor and a yaw rate sensor in the first embodiment. 12 is a flowchart illustrating a behavior control routine in the second embodiment. 3 is a flowchart illustrating an operation state determination and reference value setting control routine of a lateral acceleration sensor and a yaw rate sensor in the first embodiment. 6 is a graph showing a relationship between an absolute value of a yaw rate deviation ΔYr and a spin control amount Sc. It is a graph which shows the relationship between the absolute value of yaw rate deviation (DELTA) Yr, and the drift-out control amount Dc. It is a graph which shows the relationship between the absolute value of the integrated value Acc of Yr + KhGyV, and the reference value Yro.

Explanation of symbols

10FR to 10RL Wheel 20 Braking device 28 Master cylinder 30 Electronic controller 32FR to 32RL Wheel speed sensor 34 Steering angle sensor 36 Pressure sensor 38 Yaw rate sensor 40 Lateral acceleration sensor

Claims (3)

  An indicator of vehicle behavior deterioration as a value including Yr + KhGyV based on the vehicle lateral acceleration Gy detected by the lateral acceleration sensor and the vehicle yaw rate Yr detected by the yaw rate sensor sensor, where the vehicle speed is V and the vehicle stability factor is Kh. A vehicle behavior control device that controls the behavior of the vehicle by controlling the braking / driving force of each wheel when the value of the behavior deterioration index value is larger than the reference value is calculated, and the vehicle goes straight ahead. A vehicle behavior control device characterized in that, when the magnitude of Yr + KhGyV in a running state is larger than a reference value for abnormality determination, the reference value for behavior deterioration determination is made larger than a standard value. The steering angle is θ, the steering gear ratio is N, the vehicle wheelbase is L,
ΔYr = Yr + KhGyV− (θ × V) / (N × L)
The vehicle behavior control device according to claim 1, wherein the behavior deterioration index value is calculated according to the following. The vehicle behavior control device according to claim 1 or 2, wherein the reference value for the behavior deterioration determination is increased as the magnitude of Yr + KhGyV increases.

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