JP2006056330A - Control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vehicle capable of enhancing the accuracy in judging whether possibility of rolling over exists. <P>SOLUTION: The control device of the vehicle is equipped with a transverse acceleration sensing means to sense the transverse acceleration acting on the vehicle and directed parallel with the runway surface, a vertical acceleration sensing means to sense the vertical acceleration acting on the vehicle and directed plumb to the runway surface, a transverse acceleration correcting means to correct the transverse acceleration sensed by the transverse acceleration sensing means to a greater value when the upward directed acceleration in the vertical acceleration sensed by the vertical acceleration sensing means is larger than when it remains small, which is used as corrected transverse acceleration, and a brake control means to apply a greater braking force to the vehicle when the corrected transverse acceleration is larger than when it remains small. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle control device for preventing a vehicle from rolling over during a sudden turn.

When turning, the lateral acceleration acting outward with respect to the turning center acts on the vehicle, and the behavior of the vehicle becomes unstable. In particular, when the vehicle turns suddenly while turning at a high vehicle speed, the lateral acceleration increases and the possibility that the vehicle rolls over increases. Therefore, various control devices have been developed to prevent rollover. This control device compares the lateral acceleration applied to the vehicle with a rollover determination reference value considering the roll angle and the center of gravity height, and performs deceleration control when the lateral acceleration exceeds the rollover determination reference value ( Patent Document 1). Thus, by performing deceleration control during a sudden turn, the lateral acceleration of the vehicle is reduced and the behavior of the vehicle is stabilized.
JP-A-6-297985

  The vehicle is traveling with roll vibration during a sudden turn. Although the lateral acceleration fluctuates due to the influence of the roll vibration, the conventional control device does not take into consideration whether or not the influence of the roll vibration is likely to roll over.

  Therefore, an object of the present invention is to provide a vehicle control device that improves the accuracy of determining whether or not there is a possibility of rollover.

  A vehicle control apparatus according to the present invention detects a lateral acceleration detecting means for detecting a lateral acceleration parallel to a traveling road surface acting on the vehicle, and detects a vertical acceleration in a vertical direction with respect to the traveling road surface acting on the vehicle. Vertical acceleration detecting means, and lateral acceleration correcting means for correcting the lateral acceleration detected by the lateral acceleration detecting means to a large value when the upward acceleration in the vertical acceleration detected by the vertical acceleration detecting means is larger than when it is small, to obtain a corrected lateral acceleration And braking control means for applying a large braking force to the vehicle when the corrected lateral acceleration is larger than when it is small.

  In this vehicle control device, the lateral acceleration detecting means detects the lateral acceleration applied to the vehicle (acceleration in a direction parallel to the traveling road surface), and the vertical acceleration detecting means detects the vertical acceleration applied to the vehicle (perpendicular to the traveling road surface). Direction acceleration). Then, the control device corrects the lateral acceleration detected when the upward acceleration in the vertical acceleration detected by the lateral acceleration correction means is larger than when it is small, and obtains a corrected lateral acceleration. The corrected lateral acceleration is a lateral acceleration for determining the possibility of rollover. The larger this value, the higher the possibility of rollover. The higher the upward acceleration that generates a moment component for rollover, the higher the possibility of rollover. Therefore, when the upward acceleration is smaller than when it is small, the corrected lateral acceleration is corrected so as to increase, and the possibility of rollover is increased. Therefore, even if the lateral acceleration is small, if the upward acceleration is large, the corrected lateral acceleration becomes large, so it can be determined that the possibility of rollover is high. On the other hand, even if the lateral acceleration is large, if the upward acceleration is small, the corrected lateral acceleration is small, so it can be determined that the possibility of rollover is low. Therefore, in the control device, the braking control means applies a large braking force to the vehicle when the corrected lateral acceleration is larger than when it is small. That is, when the possibility of rollover increases, the vehicle is decelerated and the behavior of the vehicle when turning is stabilized. At this time, a larger braking force may be applied as the corrected acceleration increases, or a certain larger braking force may be applied when the corrected lateral acceleration is greater than a threshold value. As described above, in this control device, the lateral acceleration is corrected by the vertical acceleration, and therefore, the fluctuation due to the influence of the vertical acceleration can be suppressed as much as possible. Therefore, the control device can determine whether or not there is a possibility of rollover due to the corrected lateral acceleration, and can perform appropriate deceleration control. As a result, the behavior of the vehicle is stabilized and rollover can be prevented.

  The vehicle control apparatus according to the present invention includes vehicle speed detection means for detecting the vehicle speed, and the braking control means is a large control when the vehicle speed detected by the vehicle speed detection means during turning is greater than when the vehicle speed is small. It is good also as composition which makes power act.

  In this vehicle control device, the vehicle speed is detected by the vehicle speed detecting means. In the control device, the braking control means applies a large braking force to the vehicle when the vehicle speed is larger than when the vehicle speed is small during a turn. That is, as the vehicle speed increases during turning, the vehicle turns more rapidly and increases the possibility of rollover. At this time, deceleration control can be performed.

  The vehicle control apparatus according to the present invention comprises a steering angular velocity detecting means for detecting the steering angular velocity of the vehicle and a steering angle detecting means for detecting the steering angle of the vehicle, and the braking control means is detected by the steering angular velocity detecting means. A great braking force may be applied when the steering angular velocity is larger than a predetermined steering angular velocity and the steering angle detected by the steering angle detecting means is larger than the predetermined steering angle.

  In this vehicle control apparatus, the steering angular velocity is detected by the steering angular velocity detection means, and the steering angle is detected by the steering angle detection means. In the control device, when the steering angular velocity is larger than the predetermined steering angular velocity and the steering angle is larger than the predetermined steering angle, a large braking force is applied to the vehicle by the braking control means. In other words, the faster the steering angular velocity and the larger the steering angle, the sharper the turning state and the higher the possibility of rollover. At this time, deceleration control can be performed. The predetermined steering angular velocity and the predetermined steering angle are threshold values for determining whether or not the steering angular velocity and the steering angle are indicative of a sudden turning state.

  According to the present invention, by determining whether or not there is a possibility of rollover using the corrected lateral acceleration obtained by correcting the lateral acceleration by the vertical acceleration, the determination can be performed with high accuracy, and the vehicle rollover can be performed. Can be prevented.

  Embodiments of a vehicle control apparatus according to the present invention will be described below with reference to the drawings.

  In the present embodiment, the vehicle control device according to the present invention is applied to a vehicle behavior control device. The vehicle behavior control apparatus according to the present embodiment controls the behavior when the vehicle is bent by the engine output and the braking force. In particular, the vehicle behavior control device according to the present embodiment has a function for preventing rollover. In the present embodiment, a rollover prevention function in the vehicle behavior control device will be described in detail.

  With reference to FIGS. 1-3, the structure of the vehicle behavior control apparatus 1 is demonstrated. FIG. 1 is a configuration diagram of a vehicle behavior control apparatus according to the present embodiment. FIG. 2 is a model diagram of the vehicle for explaining the rollover limit lateral acceleration. FIG. 3 is an example showing temporal changes in lateral acceleration, vertical acceleration, and rollover limit lateral acceleration during a sudden turn.

  The vehicle behavior control device 1 stabilizes the behavior of the vehicle by controlling the engine output and the braking force of each wheel according to the vehicle behavior based on the detection values of various sensors during turning. In particular, when it is determined that there is a possibility that the vehicle behavior control device 1 may roll over during a sudden turn, the vehicle behavior control device 1 performs deceleration control using a braking force to prevent the rollover. For this purpose, the vehicle behavior control device 1 includes a lateral acceleration sensor 2, a vertical acceleration sensor 3, a vehicle speed sensor 4, a steering angular velocity sensor 5, brake actuators 6a to 6d for each wheel, and an ECU 7. In the present embodiment, the vehicle speed sensor 4 corresponds to the vehicle speed detection means described in the claims, and the steering angular velocity sensor 5 corresponds to the steering angular speed detection means described in the claims.

  Here, the rollover limit lateral acceleration LAR for determining whether or not there is a possibility of rollover will be described with reference to FIG. The rectangle shown in FIG. 2 is a vehicle model. h is the height of the center of gravity of the vehicle. t is one half of the tread of the vehicle. θ is the roll angle. g is the acceleration due to gravity acting on the vehicle. LA is a lateral acceleration acting on the vehicle, and is an acceleration parallel to the traveling road surface. The lateral acceleration LA is an outward acceleration with respect to the turning center generated by turning of the vehicle. VA is vertical acceleration acting on the vehicle, and is acceleration in a direction perpendicular to the traveling road surface. The vertical acceleration VA includes a gravitational acceleration g and an acceleration generated by an overturning moment or the like due to roll rigidity distribution or tire deformation. a is the lateral acceleration detected by the lateral acceleration sensor 2, and is the acceleration in the left-right direction of the vehicle. b is the vertical acceleration detected by the vertical acceleration sensor 3, and is the acceleration in the vertical direction of the vehicle. M is a rotational moment acting on the vehicle. m is the vehicle weight. In the present embodiment, the vertical acceleration has a positive value in the upward direction.

  A lateral acceleration occurs in the vehicle during turning. Therefore, a roll generation moment due to the lateral acceleration LA, which is a moment that promotes rollover, and an anti-roll generation moment due to gravity that suppresses the rollover act on the vehicle. Therefore, during the turn, the rotational moment M shown in Expression (1) acts on the vehicle.

タイヤが浮き始めるときには、ロール角θ＝０°となる。このとき、ロール発生モーメント［ｍ×ＬＡ×（ｔ×ｓｉｎθ＋ｈ×ｃｏｓθ）］が反ロール発生モーメント［ｍ×ｇ×（ｔ×ｃｏｓθ−ｈ×ｓｉｎθ）］より大きくなる瞬間であり、ロール発生モーメントと反ロール発生モーメントとが釣り合い、回転モーメントＭは０となる。したがって、式（１）は、式（２）の関係になる。このタイヤが浮き始めるときの横加速度ＬＡを横転限界横加速度ＬＡＲとし、式（２）を変形すると、式（３）の関係になる。重力加速度ｇは１Ｇなので、式（３）は式（４）の関係となる。

When the tire starts to float, the roll angle θ = 0 °. At this time, the roll generation moment [m × LA × (t × sin θ + h × cos θ)] is larger than the anti-roll generation moment [m × g × (t × cos θ−h × sin θ)]. The counter-roll generation moment is balanced and the rotational moment M becomes zero. Therefore, the formula (1) becomes the relationship of the formula (2). When the lateral acceleration LA when the tire starts to float is defined as the rollover limit lateral acceleration LAR and Equation (2) is transformed, the relationship of Equation (3) is obtained. Since the gravitational acceleration g is 1 G, the equation (3) has the relationship of the equation (4).

車両には走行路面に対して鉛直方向の加速度としては、重力加速度ｇだけが作用しているのではなく、実際には、重力加速度ｇ以外にも鉛直方向の加速度が作用している。重力加速度ｇと重力加速度以外の加速度を合わせた加速度が符号ＶＡで示す上下加速度である。したがって、式（２）に示す式は、上下加速度ＶＡを用いた式（５）となる。式（５）を変形すると、式（６）の関係になる。

In the vehicle, not only the gravitational acceleration g is acting as the acceleration in the vertical direction with respect to the traveling road surface, but also the acceleration in the vertical direction is actually acting in addition to the gravitational acceleration g. The acceleration obtained by combining the gravitational acceleration g and the acceleration other than the gravitational acceleration is the vertical acceleration indicated by reference numeral VA. Therefore, the equation shown in equation (2) becomes equation (5) using the vertical acceleration VA. When the equation (5) is transformed, the relationship of the equation (6) is obtained.

式（４）と式（６）から式（７）に示す関係となり、横転限界横加速度ＬＡＲは、横加速度ＬＡを上下加速度ＶＡで除算した値に−１を乗算した値となる。ちなみに、上下加速度の下向きをプラス値とした場合、横転限界横加速度ＬＡＲは、横加速度ＬＡを上下加速度ＶＡで除算した値となる。ここで、上下加速度ＶＡは、式（８）により、ロール角θ、センサ横加速度ａ及びセンサ上下加速度ｂを用いて求めることができる。また、横加速度ＬＡは、式（９）により、ロール角θ、センサ横加速度ａ及びセンサ上下加速度ｂを用いて求めることができる。なお、タイヤが浮き始めるのとき（ロール角θ＝０°のとき）で考えると、上下加速度ＶＡは式（８）からセンサ上下加速度ｂ自体に近似でき、横加速度ＬＡは式（９）からセンサ横加速度ａ自体に近似できる。

The relationship shown in Equation (4) and Equation (6) to Equation (7) is established, and the rollover limit lateral acceleration LAR is a value obtained by multiplying the value obtained by dividing the lateral acceleration LA by the vertical acceleration VA by -1. Incidentally, when the downward direction of the vertical acceleration is a positive value, the rollover limit lateral acceleration LAR is a value obtained by dividing the lateral acceleration LA by the vertical acceleration VA. Here, the vertical acceleration VA can be obtained by using the roll angle θ, the sensor lateral acceleration a, and the sensor vertical acceleration b according to Equation (8). Further, the lateral acceleration LA can be obtained by using the roll angle θ, the sensor lateral acceleration a, and the sensor vertical acceleration b by Equation (9). When the tire starts to float (when the roll angle θ = 0 °), the vertical acceleration VA can be approximated to the sensor vertical acceleration b itself from the equation (8), and the lateral acceleration LA is calculated from the equation (9). It can be approximated to the lateral acceleration a itself.

式（７）で示すように、横転限界横加速度ＬＡＲは、単位上下加速度当たりの横加速度ＬＡとなり、上下加速度ＶＡの影響を排除した横加速度となる。したがって、図３に示すように、横加速度ＬＡは上下加速度ＶＡの変動に応じて変動するが、横転限界横加速度ＬＡＲは上下加速度ＶＡが変動しても殆ど変動しない。そこで、横転限界横加速度ＬＡＲを用いることにより、上下加速度ＶＡの変動（ロール振動）による影響を受けることなく、横転する可能性があるか否かを判断できる。

As shown in Expression (7), the rollover limit lateral acceleration LAR is the lateral acceleration LA per unit vertical acceleration, and is the lateral acceleration excluding the influence of the vertical acceleration VA. Therefore, as shown in FIG. 3, the lateral acceleration LA varies according to the variation of the vertical acceleration VA, but the rollover limit lateral acceleration LAR hardly varies even if the vertical acceleration VA varies. Thus, by using the rollover limit lateral acceleration LAR, it is possible to determine whether or not there is a possibility of rollover without being affected by fluctuations in the vertical acceleration VA (roll vibration).

Incidentally, as shown in FIG. 3, the vertical acceleration VA fluctuates with a negative value around the gravitational acceleration g (= −9.8 m / s ² ). Therefore, when the upward acceleration in the vertical acceleration VA increases, the vertical acceleration VA has a negative value smaller than −9.8 m / s ² and the rollover limit lateral acceleration LAR increases. On the other hand, when the downward acceleration in the vertical acceleration VA is large (that is, when the upward acceleration is small), the vertical acceleration VA has a negative value larger than −9.8 m / s ² and the rollover limit lateral acceleration LAR is small.

  Now, a specific configuration of the vehicle behavior control device 1 will be described. The lateral acceleration sensor 2 is a sensor that detects acceleration acting in the left-right direction of the vehicle, and transmits the detected value to the ECU 7 as a lateral acceleration signal LS. The vertical acceleration sensor 3 is a sensor that detects acceleration acting in the vertical direction of the vehicle, and transmits the detected value to the ECU 7 as a vertical acceleration signal VS. The vehicle speed sensor 4 is a sensor that detects the speed of the vehicle, and transmits the detected value to the ECU 7 as a vehicle speed signal SS. The steering angular velocity sensor 5 is a sensor that detects the steering angular velocity input from the steering wheel, and transmits the detected value to the ECU 7 as a steering angular velocity signal AS.

  Each of the brake actuators 6a to 6d is an actuator that changes the hydraulic pressure of each of the four wheel cylinders. In each of the brake actuators 6a to 6d, a right front wheel brake pressure signal RFBS, a left front wheel brake pressure signal LFBS, a right rear wheel brake pressure signal RRBS, and a left rear wheel brake pressure signal LRBS are transmitted from the ECU 7, and each signal RFBS, LFBS, RRBS is transmitted. , The hydraulic pressure of each wheel cylinder of the four wheels is changed according to LRBS, and the braking force of the four wheels is adjusted respectively.

  The ECU 7 is an electronic control unit including a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], and the like. In the ECU 7, when the vehicle behavior control apparatus 1 is activated, a dedicated program stored in the ROM is loaded into the RAM, and each process described in the program is executed by the CPU. The ECU 7 takes in various signals LS, VS, SS, AS from the various sensors 2, 3, 4, 5 and controls the brake actuators 6a to 6d of each wheel in order to prevent rollover. In the present embodiment, the lateral acceleration correction means and the braking control means described in the claims are each configured by executing a program (software) in the ECU 7.

  The ECU 7 first performs a sudden turn determination process. For this purpose, the ECU 7 calculates the steering angle by time-integrating the steering angular velocity based on the steering angular velocity signal AS. Then, the ECU 7 determines whether or not the steering angle is greater than or equal to the steering angle threshold value and the steering angular velocity based on the steering angular velocity signal AS is greater than or equal to the steering angular velocity threshold value. When the steering angle is less than the steering angle threshold or the steering angular velocity is less than the steering angular velocity threshold, the ECU 7 does not shift to the lateral acceleration correction process. On the other hand, when the steering angle is greater than or equal to the steering angle threshold and the steering angular velocity is greater than or equal to the steering angular velocity threshold, the ECU 7 determines whether or not the vehicle speed based on the vehicle speed signal SS is greater than or equal to the vehicle speed threshold. When the vehicle speed is less than the vehicle speed threshold, the ECU 7 does not shift to the lateral acceleration correction process. When the vehicle speed is equal to or higher than the vehicle speed threshold, the ECU 7 proceeds to the lateral acceleration correction process. The steering angle threshold value, the steering angular velocity threshold value, and the vehicle speed threshold value are threshold values for determining whether or not the steering angular velocity, the steering angle, and the vehicle speed indicate that the vehicle is turning rapidly. In the present embodiment, software processing in the steering angular velocity sensor 5 and the ECU 7 corresponds to the steering angle detection means described in the claims.

When the process proceeds to the lateral acceleration correction process, the ECU 7 divides the sensor lateral acceleration a by the lateral acceleration signal LS by the sensor vertical acceleration b by the vertical acceleration signal VS, and multiplies the divided value by −1 to obtain the rollover limit lateral acceleration LAR. calculate. Here, the lateral acceleration LA is approximated by the sensor lateral acceleration a and the vertical acceleration VA is approximated by the sensor vertical acceleration b to obtain the rollover limit lateral acceleration LAR. Therefore, in the present embodiment, the lateral acceleration sensor 2 corresponds to the lateral acceleration detection means described in the claims, and the vertical acceleration sensor 3 corresponds to the vertical acceleration detection means described in the claims. For example, when the lateral acceleration VA is a positive value, the rollover limit lateral acceleration LAR becomes a positive value because the vertical acceleration VA (sensor vertical acceleration b) is a negative value in the vicinity of −9.8 m / s ² . When the acceleration (plus value) increases, the plus value increases, and when the downward acceleration (minus value) of the vertical acceleration VA increases, the plus value decreases. That is, the value of the rollover limit lateral acceleration LAR increases as the upward acceleration that generates a moment to roll the vehicle increases. As the rollover limit lateral acceleration LAR increases, the rotational moment M applied to the vehicle increases, and the possibility of rollover increases.

  When the rollover limit lateral acceleration LAR is obtained, the ECU 7 proceeds to rollover determination processing. The ECU 7 determines whether the rollover limit lateral acceleration LAR is equal to or greater than the lateral acceleration threshold. When the rollover limit lateral acceleration LAR is less than the lateral acceleration threshold, the ECU 7 does not shift to the deceleration control process. On the other hand, when the rollover limit lateral acceleration LAR is equal to or greater than the lateral acceleration threshold, the ECU 7 proceeds to a deceleration control process. The lateral acceleration threshold value is a threshold value for determining whether or not the rollover limit lateral acceleration LAR has increased to a value that may cause a rollover.

  When shifting to the deceleration control process, the ECU 7 sets brake pressure signals RFBS, LFBS, RRBS, and LRBS for each wheel in order to apply a predetermined constant brake pressure, and brake actuators 6a to 6d for each wheel. Send to each. The constant brake pressure generates the braking force necessary to reduce the vehicle speed that is higher than the vehicle speed threshold (that is, the vehicle speed that is increased to the vehicle speed that is likely to roll over) to the vehicle speed that is not likely to roll over. This is the brake pressure.

  The operation of the vehicle behavior control device 1 will be described with reference to FIG. Here, the operation when the vehicle is going to turn at a high speed on a curve will be described.

  When the vehicle starts turning at a high speed, a large lateral acceleration acts on the vehicle and roll vibrations are generated (thus, the vertical acceleration fluctuates). Each sensor 2, 3, 4 and 5 detects the acceleration applied to the left and right direction of the vehicle, the acceleration applied to the vertical direction of the vehicle, the speed of the vehicle, and the steering angular velocity, respectively, and detects each of the detection signals LS, VS, SS and AS as Is sending to. At this time, the vehicle speed and the steering angular velocity indicating a sharp turn are detected, and a large lateral acceleration is also detected.

  The ECU 7 receives the detection signals LS, VS, SS, AS from the sensors 2, 3, 4, 5. Then, the ECU 7 calculates the steering angle from the steering angular velocity obtained from the steering angle steering signal AS. Subsequently, the ECU 7 determines whether or not the calculated steering angle is greater than or equal to the steering angle threshold and the steering angular velocity is greater than or equal to the steering angular velocity threshold. Since the vehicle starts turning on the curve, if it is determined that the vehicle is greater than or equal to the steering angle threshold and greater than or equal to the steering angular velocity threshold, the ECU 7 determines whether or not the vehicle speed obtained from the vehicle speed signal SS is greater than or equal to the vehicle speed threshold. Since the vehicle is turning at a high speed, the ECU 7 determines that the vehicle speed is equal to or greater than the vehicle speed threshold, and determines that the vehicle is in a sudden turning state.

  When it is determined that the vehicle is in a sudden turning state, the ECU 7 divides the sensor lateral acceleration a obtained from the lateral acceleration signal LS by the sensor vertical acceleration b obtained from the vertical acceleration signal VS, and multiplies the divided value by −1 to roll over. The limit lateral acceleration LAR is obtained. Then, the ECU 7 determines whether or not the rollover limit lateral acceleration LAR is equal to or greater than the lateral acceleration threshold. At this time, since the vehicle is in a sudden turning state, the sensor lateral acceleration a is large, and the rollover limit lateral acceleration LAR shows a large value. Therefore, the ECU 7 determines that the rollover limit lateral acceleration LAR is equal to or greater than the lateral acceleration threshold, and determines that there is a possibility of rollover.

  Therefore, the ECU 7 sets the brake pressure signals RFBS, LFBS, RRBS, and LRBS in order to apply a constant brake pressure, and applies the brake pressure signals RFBS, LFBS, RRBS, and LRBS to the brake actuators 6a to 6d, respectively. Send. Each of the brake actuators 6a to 6d applies a brake pressure to the wheel cylinder of each wheel according to the brake pressure signals RFBS, LFBS, RRBS, and LRBS, and generates a brake force on each wheel. Then, the vehicle decelerates and the lateral acceleration applied to the vehicle (and consequently the rollover limit lateral acceleration LAR) decreases. Therefore, the behavior of the vehicle is stabilized and the curve is smoothly bent.

  According to this vehicle behavior control apparatus 1, by correcting the lateral acceleration LA with the vertical acceleration VA, the influence of the vertical acceleration can be eliminated from the lateral acceleration as much as possible, and the accuracy of the lateral acceleration (rolling limit lateral acceleration LAR) is improved. Furthermore, since the vehicle behavior control device 1 determines the possibility of rollover using the rollover limit lateral acceleration LAR, the possibility of rollover can be determined with high accuracy. Therefore, the vehicle behavior control device 1 can perform appropriate deceleration control during a sudden turn, prevent the vehicle from overturning, and obtain a stable vehicle behavior.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the present embodiment, the rollover prevention function is incorporated as one function in the vehicle behavior control apparatus, but the rollover prevention control apparatus having only the rollover prevention function may be configured, and the braking force can be controlled. It is good also as a structure integrated in another control apparatus.

  In the present embodiment, the vertical acceleration acting in the vertical direction of the vehicle is directly detected by the vertical acceleration sensor. However, the vertical acceleration may be obtained from the stroke amount of the suspension detected by the stroke sensor. The vertical acceleration may be obtained from the vehicle height detected by the sensor, the vertical acceleration may be obtained from the internal pressure of the shock absorber detected by the pressure sensor, or from the stroke amount of the active stabilizer detected by the stroke sensor. It is good also as composition which asks for vertical acceleration.

  In this embodiment, the vertical acceleration VA is approximated by the detection value of the vertical acceleration sensor, and the lateral acceleration LA is approximated by the detection value of the lateral acceleration sensor. However, the roll angle sensor detects the roll angle of the vehicle. Further, the vertical acceleration VA may be strictly determined by the equation (8), and the lateral acceleration LA may be strictly determined by the equation (9). In this case, the vertical acceleration detection means and the lateral acceleration detection means are configured by software processing in the roll angle sensor, the vertical acceleration sensor, the lateral acceleration sensor, and the ECU. In addition, if there is a sensor that can directly detect lateral acceleration parallel to the traveling road surface or a sensor that can directly detect vertical acceleration in the vertical direction relative to the traveling road surface, the sensor may be used.

  In the present embodiment, the steering angular velocity sensor is provided and the steering angle is calculated from the steering angular velocity. However, the steering angle may be directly detected by the steering angle sensor. It is good also as a structure which differentiates and calculates steering angular velocity.

  Further, in this embodiment, a constant brake pressure is applied to the brake mechanism of each wheel when the rollover limit lateral acceleration LAR becomes equal to or greater than the lateral acceleration threshold during a sudden turn. However, the rollover limit lateral acceleration LAR is large during a sudden turn. You may comprise so that big brake pressure may be added. Further, a larger brake pressure may be applied as the vehicle speed, the steering angle, and the steering angular velocity increase, or the brake pressure necessary for decelerating to a vehicle speed that eliminates the possibility of overturning the vehicle speed is applied. You may comprise as follows.

It is a block diagram of the vehicle behavior control apparatus which concerns on this Embodiment. It is a model diagram of a vehicle for explaining a rollover limit lateral acceleration. It is an example which shows the time change of the lateral acceleration at the time of sudden turning, a vertical acceleration, and a roll-over limit lateral acceleration.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle behavior control apparatus, 2 ... Lateral acceleration sensor, 3 ... Vertical acceleration sensor, 4 ... Vehicle speed sensor, 5 ... Steering angular velocity sensor, 6a ... Right front wheel brake actuator, 6b ... Left front wheel brake actuator, 6c ... Right rear wheel brake Actuator, 6d ... Left rear wheel brake actuator

Claims (3)

Lateral acceleration detection means for detecting lateral acceleration in a direction parallel to the traveling road surface acting on the vehicle;
Vertical acceleration detection means for detecting vertical acceleration in the vertical direction with respect to the traveling road surface acting on the vehicle;
Lateral acceleration correction means for correcting the lateral acceleration detected by the lateral acceleration detection means to a large value when the upward acceleration in the vertical acceleration detected by the vertical acceleration detection means is larger than when it is small, and making it a corrected lateral acceleration;
A vehicle control device comprising: braking control means for applying a large braking force to the vehicle when the corrected lateral acceleration is greater than when it is small. Vehicle speed detecting means for detecting the speed of the vehicle,
2. The vehicle control apparatus according to claim 1, wherein the braking control unit applies a large braking force when the vehicle speed detected by the vehicle speed detection unit during turning is greater than when the vehicle speed is small. Steering angular velocity detection means for detecting the steering angular velocity of the vehicle;
Steering angle detection means for detecting the steering angle of the vehicle,
The braking control means applies a large braking force when the steering angular speed detected by the steering angular speed detecting means is larger than a predetermined steering angular speed and the steering angle detected by the steering angle detecting means is larger than a predetermined steering angle. The vehicle control device according to claim 1, wherein the control device is a vehicle control device.

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