JP2006335193A - Rolling characteristic estimation device for vehicle, and rolling motion stabilization controller for vehicle using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely estimate an index for expressing the easiness in appearance of a rolling increase tendency in a vehicle, while taking an operation condition of a suspension controller into consideration, and to properly control stabilization for rolling motion. <P>SOLUTION: This rolling characteristic estimation device is provided with the suspension controller SCM capable of regulating a suspension characteristic, and estimates the index for expressing the easiness in the appearance of the rolling increase tendency in the vehicle, in response to a comparison result of an actual rolling motion detected by a rolling motion detecting means M1, with an estimated rolling motion computed by a rolling motion estimating means M3 based on a traverse acceleration detected by a traverse acceleration detecting means M2, and a suspension characteristic acquired by a suspension characteristic acquiring means M0. At least one out of braking force and driving force is controlled based on a rolling increase tendency determination reference set in response to the index. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a roll characteristic estimation device for a vehicle, and a rolling motion stabilization control device for a vehicle using the device, and in particular, a roll index representing the ease of occurrence of a roll increase tendency according to the operating state of a suspension control device. A rolling motion stabilization control device for a vehicle that can estimate a roll property of a vehicle and a vehicle rolling motion stabilization control device that stabilizes the rolling motion of the vehicle by controlling at least one of braking force and driving force in consideration of the control state of the suspension control device. Related.

  Regarding stabilization control of rolling motion of a vehicle, Patent Document 1 describes as a method of intervening vehicle motion control braking by a brake system, “at least one vehicle motion representing a tendency of the vehicle to tilt around its vertical axis. The corresponding anti-tilt threshold is defined as a dynamic characteristic variable, the instantaneous value of the characteristic variable is continuously acquired and compared with the anti-tilt threshold. As soon as the threshold is exceeded, the outer wheels are braked during cornering to prevent the vehicle from tilting about its longitudinal axis. The rolling motion of the vehicle is affected by vehicle specifications such as the height of the center of gravity of the vehicle and the characteristics of the suspension. Therefore, in the apparatus as disclosed in Patent Document 1 described above, it is desirable that control is performed based on vehicle specifications and suspension characteristics.

  On the other hand, with respect to suspension control, there are known devices that control suspension characteristics as shown in Patent Documents 2 to 4 in accordance with a running state. That is, Patent Document 2 describes an air suspension air pipe that controls opening and closing of an electromagnetic valve of an air pipe that communicates an air spring and an auxiliary air tank, and switches a spring constant of the air spring. Further, in Patent Document 3, the damping force of the shock absorber in the inner ring and the outer ring is determined according to the behavior state when the vehicle turns by using an actuator that can change the damping force of the shock absorber in a low speed region of the shock absorber expansion and contraction speed. A damping force control device that individually controls is described. Patent Document 4 describes a stabilizer efficacy control device that changes the apparent torsional rigidity of a stabilizer provided between the left and right wheels based on a signal from a lateral acceleration sensor.

  Further, in Patent Document 5, the estimation of the height of the center of gravity of the vehicle is based on the transfer function of the roll with respect to the steering angle of the dynamic model having the degree of freedom including the roll and the data collected from the actual vehicle using the roll rate sensor. Describes an apparatus for deriving the height of the center of gravity by comparing coefficients with a transfer function of a roll with respect to a steering angle obtained using the AR method (autoregressive method). Suspension characteristics (roll rigidity, etc.) are also included as parameters in the dynamic model for determining the height of the center of gravity of the vehicle. In order to estimate the characteristics related to rolling motion of the vehicle, the operation status of the suspension control device is grasped. It is necessary to accurately determine the suspension characteristics.

US Pat. No. 6,086,168 JP-A-6-127252 Japanese Patent Laid-Open No. 11-91327 JP 2000-71736 A JP-A-11-304663

  First, with reference to FIG. 2, the state quantity in the rolling motion of the vehicle will be described. Slip angle αxx on each wheel by the driver's steering wheel operation (here, subscript xx means each wheel, fr is a right front wheel, fl is a left front wheel, rr is a right rear wheel, and rl is a left rear wheel) And a lateral force SFxx is generated on each wheel, and the vehicle performs a turning motion. At this time, an inertial force (centrifugal force) Fy acts on the center of gravity of the vehicle so as to balance the lateral force generated by the wheels. The position of the center of gravity of the vehicle does not coincide with the center of rotation of the rolling motion (roll center), and there is a distance Hs (hereinafter referred to as roll arm length) between the center of gravity of the vehicle and the center of the roll. Fy) occurs. As a result, a rolling motion is caused in the vehicle by the rolling moment, and if this becomes too large, a tendency of increasing the roll of the vehicle appears.

  The roll increase tendency of a vehicle occurs when a sudden rolling motion occurs (hereinafter referred to as a dynamic roll increase trend) and when it occurs in a relatively slow rolling motion (hereinafter referred to as a static roll increase trend). And an intermediate roll increase tendency (hereinafter referred to as an intermediate roll increase tendency) between a dynamic roll increase tendency and a static roll increase tendency.

  The dynamic roll increase tendency is that the rolling motion suddenly increases due to the driver's sudden steering operation or turning back steering, the suspension member collides with the contraction side bound stopper, and the wheel on the suspension extension side tends to be lifted by the impact. Caused by that. Increasing the spring force and damping force by the suspension control device has a characteristic that the rolling motion of the vehicle does not occur abruptly. Therefore, the suspension control device has the effect of stabilizing the roll posture of the vehicle and suppressing the tendency of the vehicle to increase the roll while improving the ride comfort and the handling stability.

  On the other hand, the static roll increasing tendency occurs in a gradual rolling motion in which the roll angle gradually increases despite the small roll angular velocity. The main reason for this is that the position of the center of gravity of the vehicle is high due to an increase in occupants and changes in loading conditions. This is because when the roll arm length Hs is large, the rolling moment Mx is large even if the same inertial force Fy is applied, and a tendency to increase the roll tends to occur. Therefore, in order to determine the roll increase tendency in accordance with the rolling motion characteristic of the vehicle and perform the rolling motion stabilization control, a characteristic (hereinafter referred to as a roll index) representing the ease of appearance of the roll increase tendency including the height of the center of gravity of the vehicle. ).

  Therefore, the present invention provides an index representing the ease of appearance of a roll increasing tendency in a rolling motion of a vehicle in a vehicle having a suspension control device capable of adjusting suspension characteristics, taking into account the operation status of the suspension control device. It is an object of the present invention to provide a vehicle roll characteristic estimation apparatus that can be well estimated.

  In addition, the present invention provides a vehicle having a suspension control device capable of adjusting suspension characteristics, which suppresses the tendency of the vehicle to increase in rolls and performs rolling motion stabilization control in consideration of the operation status of the suspension control device. Another object is to provide a rolling motion stabilization control device.

  In order to achieve the above object, according to the present invention, a roll characteristic of a vehicle that is mounted on a vehicle including a suspension control device capable of adjusting a suspension characteristic and estimates the roll characteristic of the vehicle is provided. In the estimation apparatus, a suspension characteristic acquisition unit that acquires the suspension characteristic, a rolling motion detection unit that detects an actual rolling motion of the vehicle during traveling, a lateral acceleration detection unit that detects a lateral acceleration of the vehicle, A rolling motion estimating means for estimating a rolling motion of the vehicle by calculating based on a lateral acceleration detected by the acceleration detecting means and a suspension characteristic acquired by the suspension characteristic acquiring means; and an actual rolling motion detected by the rolling motion detecting means; Comparison with the estimated rolling motion calculated by the rolling motion estimation means Depending on the fruit, it is obtained by a further comprising a roll index estimation means for estimating a roll indicator of roll increasing tendency of appearing ease of the vehicle.

  And, as described in claim 2, in a rolling motion stabilization control device for a vehicle that is mounted on a vehicle equipped with a suspension control device capable of adjusting suspension characteristics and stabilizes the rolling motion of the vehicle during traveling. Suspension characteristic acquisition means for acquiring the suspension characteristic, rolling motion detection means for detecting the actual rolling motion of the vehicle while traveling, lateral acceleration detection means for detecting lateral acceleration of the vehicle, and the lateral acceleration detection means Rolling motion estimation means for estimating the rolling motion of the vehicle by calculating based on the lateral acceleration to be detected and the suspension characteristics acquired by the suspension characteristic acquisition means, the actual rolling motion and the rolling motion estimation detected by the rolling motion detection means Comparison with estimated rolling motion calculated by means And a roll index estimation means for estimating a roll index indicating the ease of occurrence of the roll increase tendency of the vehicle, and a criterion for determining the roll increase tendency of the vehicle based on the roll index estimated by the roll index estimation means. Roll increasing tendency determination criterion setting means to be set; and control means for performing at least one of braking force control and driving force control of the vehicle based on the roll increasing tendency determination criterion set by the roll increase tendency determination criterion setting means; It is good to have a configuration comprising

  Alternatively, as described in claim 3, in a vehicle rolling motion stabilization control device that is mounted on a vehicle equipped with a suspension control device capable of adjusting suspension characteristics and stabilizes the rolling motion of the vehicle during traveling. Suspension characteristic acquisition means for acquiring the suspension characteristic, rolling motion detection means for detecting the actual rolling motion of the vehicle while traveling, lateral acceleration detection means for detecting lateral acceleration of the vehicle, and the lateral acceleration detection means Rolling motion estimation means for estimating the rolling motion of the vehicle by calculating based on the lateral acceleration to be detected and the suspension characteristics acquired by the suspension characteristic acquisition means, the actual rolling motion and the rolling motion estimation detected by the rolling motion detection means Comparison with estimated rolling motion calculated by means According to the result, a roll increase tendency determination criterion setting means for setting a determination criterion for the roll increase tendency of the vehicle, and a braking force control for the vehicle based on the roll increase tendency determination criterion set by the roll increase tendency determination criterion setting means And a control means for controlling at least one of the driving force controls.

  Furthermore, as defined in claim 4, it is assumed that a failure determination means for determining a failure of the suspension control device is provided, and the roll increase tendency determination criterion setting means is configured to determine the vehicle based on the determination result of the failure determination means. You may comprise so that the criteria of determination of the roll increase tendency may be changed and set.

  Since this invention is comprised as mentioned above, there exist the following effects. That is, in the vehicle roll characteristic estimation apparatus according to claim 1, the rolling motion of the vehicle is estimated and calculated based on the lateral acceleration detected by the lateral acceleration detection means and the suspension characteristics acquired by the suspension characteristic acquisition means, and the calculation result The roll index is estimated according to the comparison result between the estimated rolling motion and the actual rolling motion, and the control status of the suspension control device is reflected in the roll index, so the roll index is accurately estimated. be able to.

  According to the rolling motion stabilization control device for a vehicle according to claims 2 and 3, since the rolling motion stabilization control can be performed based on the suspension characteristics that affect the stabilization of the rolling motion of the vehicle, It is possible to appropriately suppress the roll increase tendency and to suppress unnecessary control operations.

  Furthermore, according to the rolling motion stabilization control device for a vehicle according to claim 4, the roll increase tendency determination criterion setting means changes and sets the determination criterion for the roll increase tendency of the vehicle based on the determination result of the failure determination means. Therefore, if the suspension control device breaks down, it can be controlled to suppress the roll increase tendency at an early stage.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall configuration of a vehicle roll characteristic estimation device and a vehicle rolling motion stabilization control device according to an embodiment of the present invention. In FIG. 1, the vehicle of this embodiment includes a suspension control device SCM capable of adjusting suspension characteristics, and the roll property estimation device mounted on the vehicle includes suspension property acquisition means M0 for acquiring suspension properties. ing. Further, a rolling motion detection means M1 for detecting the actual rolling motion of the running vehicle, a lateral acceleration detection means M2 for detecting the lateral acceleration of the vehicle, and a lateral acceleration and suspension characteristic acquisition means detected by the lateral acceleration detection means M2. The rolling motion estimation means M3 that calculates based on the suspension characteristics acquired by M0 and estimates the rolling motion of the vehicle, the actual rolling motion detected by the rolling motion detection means M1, and the estimated rolling motion calculated by the rolling motion estimation means M3 According to the comparison result, there is provided a roll index estimation means M4 for estimating a roll index indicating the ease of appearance of the roll increase tendency of the vehicle. For example, the estimation accuracy of the roll index is improved by including the suspension characteristic in the parameter of the transfer function used for estimating the roll index and reflecting the control state of the suspension control device SCM.

  The rolling motion stabilization control device for a vehicle is mounted on a vehicle equipped with a suspension control device SCM, includes the roll characteristic estimation device described above, and, as indicated by a broken line, the roll index estimated by the roll index estimation means M4. Based on the roll increase tendency determination criterion setting means M5 for setting a determination criterion for the roll increase tendency of the vehicle, and the braking force control and driving of the vehicle based on the roll increase tendency determination criterion set by the roll increase tendency determination criterion setting means M5. A control means M6 that performs at least one of the force controls can be provided.

  Further, as a rolling motion stabilization control device for a vehicle, an actual rolling motion and rolling motion estimation means M3 detected by the rolling motion detection means M1, as indicated by a broken line arrow in FIG. 1, without providing the roll index estimation means M4. The roll increase tendency determination criterion setting unit M5 may set the determination criterion for the roll increase tendency of the vehicle in accordance with the comparison result with the estimated rolling motion calculated by.

  Further, as indicated by a broken line in FIG. 1, it is assumed that failure determination means M7 for determining a failure of the suspension control device SCM is provided, and the roll increase tendency determination criterion setting means M5 is based on the determination result of the failure determination means M7. It may be configured to change and set the criterion for determining the roll increase tendency. That is, it can be assumed that if the suspension control device SCM breaks down, the tendency to increase the roll is likely to occur, so the roll increase tendency determination criterion setting means M5 stabilizes the rolling motion, for example, with a small criterion. Therefore, it is possible to set the braking force control and the driving force control to be performed earlier.

  The rolling motion in the above-described rolling motion detection means M1 and rolling motion estimation means M3 can be classified as shown in FIG. 3, and the rolling motion of the vehicle can be expressed as a state quantity. In FIG. 3, the roll state quantity representing the rolling motion of the vehicle can be classified into an output state quantity that is an output (result) of the rolling motion and an input state quantity that is an input (cause). Here, the output state quantity relating to the output of the rolling motion includes a roll angle Ra and a roll angular velocity Rr. If attention is paid to the movement of the suspension, the suspension stroke STxx and the speed dSTxx correspond to the roll output state quantity. As the state quantity (input state quantity) representing the input of the rolling motion, the steering angle δsw and the steering angular speed dδsw of the steering wheel SW, the wheel slip angle αxx and the speed dαxx, the vehicle slip angle β and the speed dβ, There are a lateral force SFxx and its time change dSFxx, a vehicle body inertia force Fy and its time change dFy, a rolling moment Mx which is a direct input of the rolling motion, and its time change dMx.

  Further, since the inertial force (the sum of the lateral forces of the wheels) corresponds to the lateral acceleration of the vehicle, the lateral acceleration (detected lateral acceleration) Gy detected by a lateral acceleration sensor GY described later and its time change dGy are also input. It can be called quantity. The lateral force of the wheel generates a yawing moment. As a result, the vehicle performs a yawing motion. The yawing moment Ym and its time change dYm, the yaw angular velocity Yr and its time change (yaw angular acceleration) dYr are also affected by the rolling motion. It can be an input state quantity.

Here, since the lateral acceleration Gy of the vehicle can also be expressed using other state quantities as shown by the following equations, these can also be used as input state quantities. First, the calculated lateral acceleration Gy1 obtained from the yaw angular velocity Yr is calculated as follows.
Gy1 = V · Yr (1)
Here, V is the vehicle speed.

Similarly, the time change dGy1 of the calculated lateral acceleration Gy1 is calculated as follows.
dGy1 = V · dYr (2)
Here, dYr is a time change (yaw angular acceleration) of the yaw angular velocity Yr.

The calculated lateral acceleration Gy2 obtained from the steering angle δsw of the steering wheel SW is calculated as follows.
Gy2 = {V ² / [L · (1 + Kh · V ² )]} · (δsw / N) (3)
Here, L is a wheel base, Kh is a stability factor, and N is a steering gear ratio.

Further, the following equation (3 ′) can also be obtained by setting Kh = 0 (neutral steer).
Gy2 = (V ² / L) · (δsw / N) (3 ′)

Similarly, the time change dGy2 of the calculated lateral acceleration Gy2 is calculated as follows.
dGy2 = {V ² / [L · (1 + Kh · V ² )]} · (dδsw / N) (4)
Here, dδsw is the steering angular velocity of the steering wheel SW.

In addition, the following equation (4 ′) can also be used as Kh = 0 (neutral steer).
dGy2 = (V ² / L) · (dδsw / N) (4 ′)

The roll state quantities (represented by Rst) representing the above rolling motion are summarized as shown in [Table 1] below. Here, the roll amount Rmg and the roll speed Rsp representing the magnitude and speed of the rolling motion are classified and shown. Further, focusing on the result (output) and cause (input) of the rolling motion, it can be classified into a roll output state quantity (Rstr) and a roll input state quantity (Rsti). Here, the roll output state quantity Rstr is the roll output quantity Rmgr and the roll output speed Rspr, and the roll input state quantity Rsti is the roll input quantity Rmgi and the roll input speed Rspi. In [Table 1] below, the state quantities obtained by calculation are indicated by arrows in parentheses.

  There are cases of right turn and left turn in vehicle motion, and these are generally treated as positive and negative signed values, for example, left turn as positive and right turn as negative. However, when explaining the magnitude relationship of values, considering the sign of positive and negative, the representation of the magnitude relationship becomes complicated. Therefore, in the following explanation, the magnitude of the absolute value is not particularly limited. It represents a relationship.

  Next, FIG. 4 shows an overall configuration of a vehicle including a rolling motion stabilization control device for a vehicle according to an embodiment of the present invention. The brake system electronic control unit ECU1, the engine system electronic control unit ECU2, and the instrument panel system electronic control unit ECU3 are connected via a communication bus so that each system can share system information. ing. Further, a steering angle sensor SA that detects a steering angle (hereinafter simply referred to as a steering angle) δsw of the steering wheel SW, a longitudinal acceleration sensor GX that detects a longitudinal acceleration Gx of the vehicle, and a lateral acceleration sensor GY that detects a lateral acceleration Gy of the vehicle. The yaw angular velocity sensor YR for detecting the yaw angular velocity Yr of the vehicle and the roll angular velocity sensor RR for detecting the roll angular velocity Rr of the vehicle are connected to the communication bus and configured to provide sensor information to each electronic control unit. .

  The brake actuator BRK generates a braking force on each wheel in accordance with the operation of the brake pedal BP by the driver, and responds to a signal from the brake system electronic control unit ECU1 when the vehicle rolling motion stabilization control described later is required. Thus, the braking force of each wheel can be controlled independently. In order to detect the operation amount of the brake pedal BP of the driver, the brake actuator BRK is provided with a pressure sensor PS, and the detected pressure Pmc is supplied to the brake system electronic control unit ECU1. The braking force control for stabilizing the rolling motion is executed even when the driver is not operating the brake pedal BP. An operation amount Ap of a driver's accelerator pedal (not shown) is detected by an accelerator pedal sensor AP connected to the engine system electronic control unit ECU2, and sent to the brake system electronic control unit ECU1 via the communication bus. .

  The suspension of each wheel WHxx includes an air suspension ASxx (for example, described in Patent Document 2 described above) capable of switching and controlling a spring constant, and a damping force variable shock absorber SAxx (for example, Patent Document 3 described above) capable of controlling a damping force. Is provided). Further, between the front wheels and the rear wheels, control stabilizers FT and RT (for example, described in the above-mentioned Patent Document 4) capable of controlling roll rigidity are provided. These suspension control devices are controlled by an air suspension system electronic control unit ECU4, a shock absorber system electronic control unit ECU5, and a stabilizer system electronic control unit ECU6. These electronic control units are connected to a communication bus and share sensor signal information and calculation processing information in the electronic control unit. The vehicle suspension does not have to include all these suspension control devices, and includes at least one of the suspension control devices.

  Each wheel WHxx is provided with a wheel speed sensor WSxx, which is connected to the brake system electronic control unit ECU1, and the rotation speed of each wheel, that is, a pulse signal having a pulse number proportional to the wheel speed is generated by the brake system electronic. It is configured to be input to the control unit ECU1. Then, in the brake system control unit ECU1, a longitudinal speed (vehicle speed) V of the vehicle is calculated based on the wheel speed signal Vwxx from the wheel speed sensor WSxx. Further, the electronic control unit ECU4 for air suspension control is provided with a stroke sensor STxx for detecting the suspension stroke Stxx of each wheel WHxx in order to adjust the vehicle height.

  The rolling motion stabilization control of the present embodiment is executed in the brake system electronic control unit ECU1. When the rolling motion stabilization control is executed, the braking force acting on each wheel is independently controlled to suppress the tendency of the vehicle to increase in rolls. Further, in order to control the driving force acting on the wheels, a command signal is sent to the engine system electronic control unit ECU2 via the communication bus, and the throttle opening, ignition retard, and fuel injection amount are controlled according to the situation. Thus, the engine torque is reduced and the driving force of the wheels is controlled. At this time, a notification command is sent to the instrument panel electronic control unit ECU3 via a communication bus, and visual and audible notification means (not shown) are driven to notify the driver of the operating state of the device. Is done.

  Next, referring to FIG. 5 and FIG. 6, an example of a specific aspect of the suspension control device SCM shown in FIG. 1 and suspension characteristics (roll rigidity Kx and roll damping Cx) controlled by the suspension control device SCM. Will be described. FIG. 5 shows an air suspension control device ASxx that can change the spring constant and a shock absorber control device SAxx that can variably control the damping force.

  The air suspension control device ASxx includes a main air chamber CMxx that constitutes a main spring and a sub air chamber CSxx that constitutes a sub spring, and a valve that controls communication or non-communication between the main air chamber CMxx and the sub air chamber CSxx. The spring constant of the air suspension is made variable by VSxx. The spring constant characteristic (roll stiffness Kx) of the air suspension control device can be calculated based on the energization or non-energization information to the valve VSxx. The spring constant characteristic (roll rigidity Kx) of the air suspension control device can also be calculated based on the target spring constant characteristic that is calculated in the air suspension system electronic control unit ECU4.

  On the other hand, in the shock absorber control device SAxx, damping force control is performed by changing the orifice area that communicates the upper chamber and the lower chamber of the shock absorber. The orifice area is adjusted by an actuator DAxx such as a rotary actuator or a linear solenoid valve (not shown). Based on the drive information (rotation angle, current, etc.) of the actuator DAxx, the damping characteristic (roll damping Cx) of the shock absorber controller SAxx can be calculated. Further, the damping characteristic (roll damping Cx) of the shock absorber control device SAxx can be calculated based on the target damping force characteristic that is calculated in the shock absorber system electronic control unit ECU5.

  FIG. 6 shows a stabilizer control device FT or RT provided between the front wheels or the rear wheels. The stabilizer bar SB is divided into two, and one stabilizer bar SBr is connected to the motor rotor side (via the reduction gear), and the other stabilizer bar SBl is connected to the motor stator side. When the motor M is energized, the rotor and the stator of the motor M are relatively twisted, whereby the torsion spring rigidity of the entire stabilizer control device FT (or RT) is made variable. In this device, the torsion spring characteristic (roll stiffness Kx) of the stabilizer control device FT (or RT) can be calculated based on the current driving the motor M or the relative angular displacement of the divided stabilizer bar SB. it can. Further, the torsion spring characteristic (roll stiffness Kx) of the stabilizer control device FT (or RT) can be calculated based on the target screw spring characteristic calculated in the stabilizer system electronic control unit ECU6.

  FIG. 7 shows a processing example of the rolling motion stabilization control in the present embodiment. Regarding the roll increase tendency determination criterion and the control criterion, the subscript 1 turns left and the subscript 2 turns right regarding the turning direction of the vehicle. To express. First, in step 100, initialization is performed, and in step 101, sensor signals and communication signals are read. Based on these signals, the roll amount Rmg is calculated in step 102, and the roll speed Rsp is calculated in step 103. Here, the roll amount Rmg and the roll speed Rsp are the state amounts shown in the above [Table 1].

  Next, in step 104, the roll state quantity representing the actual rolling motion state of the vehicle is expressed using the roll amount Rmg and the roll speed Rsp. Then, in step 105, as shown in FIGS. 6 and 7, the roll stiffness and roll damping characteristics of the vehicle are calculated based on the control state of the suspension control device. Also, the control state of the suspension control device includes failure information of the control device, and information on whether or not the suspension control device is operating normally is also acquired. Note that the control information of these suspension control devices is performed via a communication bus.

  In step 106, it is first determined whether or not the suspension control device is operating normally. When the suspension control device is out of order, the process proceeds to step 117, and control is executed when the suspension control device described later is out of order. If the suspension control device is operating normally, the routine proceeds to step 107, and criteria Ref1 and Ref2 for determining the roll increase tendency of the vehicle when the suspension control device is normal (hereinafter simply referred to as roll increase tendency determination criteria). Is set. In step 107, it is determined whether or not the roll state quantity (Rmg, Rsp) calculated in step 104 is within the control region with respect to the roll increase tendency determination criteria Ref1 and Ref2. Here, the inside of the control region is a region where it is necessary to execute the braking force control and the driving force control in order to stabilize the rolling motion.

  If it is determined in step 108 that the roll state quantity (Rmg, Rsp) is not within the control region with respect to the roll increase tendency determination criteria Ref1 and Ref2, the braking force control and the driving force control are not executed. It returns to step 101. On the other hand, if it is determined that the current position is within the control region, then in step 109, control references Trf1 and Trf2 that serve as references for executing the braking force control and the driving force control are set. In step 110, the roll state quantity deviation (state quantity deviation Dr) is calculated based on the roll state quantity (Rmg, Rsp) and the control criteria Trf1 and Trf2.

  Thus, the process proceeds to step 111, where the target braking force BFdxx of each wheel is calculated based on the state quantity deviation Dr. In step 112, the brake actuator BRK is controlled according to the target braking force BFdxx, and the braking force of each wheel is controlled. In setting the target braking force, the amount of operation of the brake pedal BP by the driver (for example, the master cylinder pressure and input as the detected pressure Pmc) is also taken into consideration.

  Similarly, with respect to the driving force control, in step 113, the target driving force is calculated based on the state quantity deviation Dr, and the reduction amount of the engine torque is determined. In step 114, the throttle opening is determined by the engine system actuator. The ignition delay and the fuel injection amount are controlled. In setting the target driving force, the driver's accelerator pedal operation amount Ap is also taken into consideration.

  Next, the setting of the roll increase tendency determination criterion in step 107 of FIG. 7 will be described with reference to FIG. The criterion for determining the roll increase tendency is a two-dimensional relationship (map) in which a state quantity (roll amount Rmg) representing the magnitude of the rolling motion on the X axis and a state quantity (roll speed Rsp) representing the speed of the rolling motion on the Y axis. ) Is set. Here, the roll amount Rmg and the roll speed Rsp are the state amounts shown in [Table 1]. In this way, by determining the roll increase tendency as a two-dimensional map, a dynamic roll increase tendency that occurs during sudden steering, a static roll increase tendency that easily occurs at the high center of gravity of the vehicle, and an intermediate between them. It is possible to appropriately respond to the tendency of personality rolls to increase.

  By the way, in the initialization of step 100, the roll increase tendency determination criterion is initially set to Ref1o and Ref2o. In this initial setting, the suspension control device is set to have low roll rigidity and low roll damping, and is set in consideration of a case where a roll increase tendency is likely to occur. That is, the roll increase tendency determination criterion is set as a small value characteristic. Then, in consideration of the suspension characteristics of the suspension control device calculated in step 105, the roll increase tendency determination criterion is changed from the initial characteristics Ref1o and Ref2o to Ref1 and Ref2 adapted to the actual vehicle state. Since the roll increase tendency determination criterion is changed according to the control state of the suspension control device, unnecessary braking force and drive force control operations are suppressed, and the driver feels uncomfortable.

  Furthermore, the roll increase tendency determination criterion can be set as a characteristic having a lower limit value Rmg1 and an upper limit value Rmg2 in the roll amount. By setting the lower limit value Rmg1, unnecessary control operations on the low friction coefficient road surface can be suppressed. In addition, by setting the upper limit value Rmg2, it is possible to reliably suppress the roll increase tendency when the turning state becomes large.

  Next, the arithmetic processing in steps 108 to 110 in FIG. 7 will be described with reference to FIG. FIG. 9 shows a scene in which the vehicle first starts a left turn, then turns back to a right turn and returns to a straight traveling state. When the vehicle is traveling straight ahead, the roll state of the vehicle is at the zero point. Then, the vehicle starts the first turn by the driver's steering wheel operation (left turn in FIG. 9), and the roll amount Rmg and the roll speed Rsp increase. Step 108 is performed when the roll state quantity (Rmg, Rsp) of the vehicle crosses the roll increase tendency determination criterion Ref1 when turning left based on the suspension characteristics (point A shown in FIG. 9). Then, it is determined that it is within the control region.

  In step 109 of FIG. 7, control standards Trf1 and Trf2 used for braking force control and driving force control are set as follows. That is, the roll amount Rmg when the roll state amount (Rmg, Rsp) of the vehicle crosses the roll increase tendency determination reference Ref1 in the increasing direction is set as the control reference Trf1 in the first turning direction (left turn in FIG. 9). Is done. At this time, the control reference Trf2 in the second turning direction (right turn in the figure) is set symmetrically with respect to the origin 0 of the control reference Trf1.

  In step 110 in FIG. 7, the deviation between the actual roll amount Rmg and the control reference Trf1 is calculated as the state quantity deviation Dr. In the roll state at point B in FIG. The vertical distance to Trf1 is calculated as the state quantity deviation Dr. Further, the state quantity deviation in the second turn is obtained as a deviation from the control reference Trf2 in the second turn. In the roll state at the point E in FIG. 9, the vertical distance from the roll amount at the point E to the control reference Trf2 is calculated as the state amount deviation Dr.

  The determination as to whether or not the vehicle has entered the control region in the first turn is made based on the relationship between the roll state quantity (Rmg, Rsp) and the roll increase tendency determination criterion. However, once the roll state quantities (Rmg, Rsp) are within the control region and the control references Trf1 and Trf2 are set, the determination within the control region is performed based on the control reference in the subsequent arithmetic processing. That is, the departure from the control region in the first turning direction is determined by the roll state quantity crossing the control reference Trf1 in the decreasing direction (point C in FIG. 9). As described above, since the control criteria Trf1 and Trf2 are set as characteristics different from the roll increase tendency determination criteria Ref1 and Ref2, the determination of the roll increase tendency of the vehicle is performed after the rolling motion becomes sufficiently small. The power control and the driving force control are finished, and the control effect can be surely exhibited.

  Whether or not the vehicle has entered the control region for the second turn is determined when the roll state quantity (Rmg, Rsp) exceeds the control reference Trf2 in the increasing direction (point D in FIG. 9). As in the first turn, the second turn is outside the control range when the roll state quantity crosses the control reference Trf2 in the decreasing direction (point F in FIG. 9). In the above description, the case where the turning of the vehicle is first started from the left turn is described. However, when the vehicle starts from the right turn, the procedure is reversed.

  Next, the target braking force BFdxx calculated in step 111 of FIG. 7 will be described with reference to FIG. The target braking force BFdxx of each wheel is calculated based on the state quantity deviation Dr. The target braking force BFdxx of the turning outer front wheel, the turning outer rear wheel, and the turning inner rear wheel is calculated on the basis of the state quantity deviation Dr so that the roll increase tendency of the vehicle can be suppressed while maintaining an appropriate yawing moment. Since the braking force control is executed according to the state quantity deviation, a strong braking force is applied and suppressed when the roll increasing tendency of the vehicle is large. On the other hand, when the state quantity deviation is small, a braking force necessary for stabilizing the rolling motion is applied.

  In addition, in order to quickly decelerate the vehicle while appropriately controlling the yawing moment of the vehicle, a single or a plurality of wheels can be set as the target wheels for the braking force control. For example, it is also effective to apply a braking force to all four wheels, one wheel on the outer front wheel, two front wheels and the inner rear wheel, or two front wheels and the outer rear wheel.

  In the stabilization control shown in FIG. 7, a two-dimensional map is used. However, the present invention is not limited to this, and in order to determine or control the roll increase tendency, the above-mentioned [ The braking force control and driving force for stabilizing the rolling motion of the vehicle by using any one of the roll state quantities in Table 1 and setting the criterion for determining the roll increase tendency based on the suspension characteristics controlled by the suspension control device. Control can be performed.

  The case has been described above where it is determined in step 106 in FIG. 7 that the suspension control device is normal. On the other hand, if the suspension control device information obtained via the communication bus determines that the suspension control device is out of order in step 106, the process proceeds to step 117, and the roll increases when the suspension control device fails. Trend determination criteria (hereinafter referred to as failure roll increase tendency determination criteria) Ref1x and Ref2x are set.

  Then, based on the roll increase tendency determination criteria at the time of failure Ref1x and Ref2x, the determination in the control region is performed in the same manner as in the case where the above-described suspension control device is normal (step 118), the braking force control and the driving force Control standards Trf1x and Trf2x used for control are set (step 119), and a state quantity deviation Drx is calculated (step 120). Thus, based on the state quantity deviation Drx, braking force control and driving force control for stabilizing the rolling motion of the vehicle are performed in the same manner as described above.

  Next, with reference to FIG. 11 and FIG. 12, the setting of the roll increasing tendency judgment criterion at the time of failure will be described. In the following, only the characteristics of the first quadrant showing the left turn are shown, but the right turn is set as a symmetrical characteristic with respect to the origin 0. As indicated by a solid line in FIG. 11, the roll increase tendency determination criterion Ref1x when it is determined that the suspension control device has failed is smaller than the initial characteristic Ref1o of the roll increase tendency determination criterion set in step 100. The characteristic is changed. As a result, braking force control and driving force control for stabilizing the rolling motion are executed even in a smaller roll state quantity, so that even if the suspension control device breaks down, the tendency of the vehicle roll to increase is suppressed. Is done.

  The suspension characteristics can be broadly divided into spring elements (coil springs, air springs, stabilizers, etc.) that generate force depending on the suspension stroke, and damping elements (shock absorber, etc.) that generate force depending on the stroke speed. And classified. Since the roll amount Rmg is a state amount obtained corresponding to the spring element and the roll speed Rsp is respectively corresponding to the damping element, the roll increasing tendency depends on which element the suspension control device has failed. The method for changing the judgment criteria can also be changed.

  For example, as shown in FIG. 12, when the spring element fails, the roll increase tendency determination characteristic Ref1o when the suspension control device is normal is in the roll amount direction ( The characteristic is changed to the Ref1xs characteristic (dashed line) reduced in the X-axis direction in FIG. On the other hand, when the damping element fails, the roll increase tendency determination characteristic Ref1o is changed to the Ref1xd characteristic (solid line) that is reduced in the roll speed direction (Y-axis direction in FIG. 12). Thus, the roll increase tendency determination characteristic at the time of failure can be changed according to the function of the suspension control device.

  In FIG. 11 and FIG. 12, the roll increase tendency determination criteria Ref1x and Ref2x at the time of failure are set as characteristics different from the initial characteristics Ref1o and Ref2o of the roll increase tendency determination criteria. It is also possible to set the characteristic to be a characteristic that is expected even when the suspension control device fails, and the initial characteristic of the roll increase tendency determination criterion and the roll increase tendency determination criterion at the time of failure can be the same characteristic. In this case, when it is determined that the suspension control device is normal, the roll increase tendency determination criterion is changed from the initial characteristics Ref1o and Ref2o to the characteristics Ref1 and Ref2 adapted to the actual vehicle state, but the suspension control apparatus fails. Is determined, the initial characteristics Ref1o and Ref2o are returned from Ref1 and Ref2.

  As described above, in a vehicle equipped with a suspension control device, a roll increase tendency determination criterion is set according to the control state of the suspension control device, and rolling motion stabilization control is performed according to suspension characteristics. As described with reference to FIG. 2, the position of the center of gravity of the vehicle changes due to an increase in occupants, changes in loading conditions, etc., and the characteristic (roll index) indicating the tendency of the vehicle to increase its roll changes. According to the control state of the control device, it is possible to accurately determine the ease of appearance of the vehicle roll increase tendency. The roll index estimation described below is processed before step 107 shown in FIG. 7, and the result (roll index) is reflected in the setting of the roll increase tendency determination criterion.

First, the rolling motion of the vehicle can be expressed by the following equation of motion (5).
Ix · d ² φ / dt ² + Cx · dφ / dt + Kx · φ
= Ms · Hs · Gy + Ms · g · Hs · φ (5)
Where φ is the roll angle, Ix is the roll inertia mass, Cx is the roll damping, Kx is the roll stiffness, Ms is the sprung mass of the vehicle, and Hs is the roll arm length (from the roll center axis to the center of gravity height at the vehicle center of gravity position). Distance), Gy is the lateral acceleration, and g is the gravitational acceleration.

In the above formula (5), since the roll angle φ of the vehicle does not become so large, the second term on the right side can be ignored. Then, when Laplace transform is performed on the equation (5) to obtain the transfer function of the roll angle φ, the following equation (6) is obtained.
φ (s) / Gy (s) = (Ms · Hs) / (Ix · s ² + Cx · s + Kx) (6)
Here, s is a Laplace operator.

Further, when the transfer function of the roll angular velocity Rr is obtained based on the equation (6), the following equation (7) is obtained.
Rr (s) / Gy (s) = (Ms · Hs · s) / (Ix · s ² + Cx · s + Kx)
... (7)

  As is apparent from the above equations (6) and (7), the roll angle and roll angular velocity obtained based on the transfer function of the rolling motion of the vehicle with respect to the lateral acceleration, and the roll angle detected as the output of the vehicle motion And the coefficient (Ms · Hs) can be obtained by comparing the roll angular velocity. Since the coefficient (Ms · Hs) is a value including the characteristics of the center of gravity, this can be used as the roll index RI.

  The sprung mass Ms of the vehicle can be estimated from the braking force acting on the wheels and the deceleration of the vehicle. Therefore, each time the vehicle is decelerated, the vehicle sprung mass Ms is estimated to determine the roll arm length Hs, which can be used as the roll index RI.

  FIG. 13 shows a case where a roll index is obtained based on a transfer function of lateral acceleration and roll angular velocity. That is, the estimated roll angular velocity Rre is calculated based on the above equation (7) using the lateral acceleration Gy detected by the lateral acceleration sensor GY. Then, the roll index RI can be calculated by comparing the roll angular velocity Rr detected by the roll angular velocity sensor RR with the estimated roll angular velocity Rre. In this case, the roll damping Cx and the roll stiffness Kx in the above equation (7) are determined based on the control state of the suspension control device.

  FIG. 14 shows a case where the roll index is obtained based on the transfer function of the lateral acceleration and the roll angle. That is, the estimated roll angle Rae is calculated based on the above equation (6) using the lateral acceleration Gy detected by the lateral acceleration sensor GY. Then, from the suspension stroke Stxx detected by the suspension stroke sensor STxx, the stroke difference between the left and right suspensions is obtained, and the roll angle Ra is calculated. The roll index RI can be calculated by comparing this with the estimated roll angle Rae. In this case, the roll damping Cx and the roll stiffness Kx in the above equation (6) are determined based on the control state of the suspension control device.

  13 and 14, the estimated roll output state quantity calculated by the transfer function of the rolling motion using the lateral acceleration and the roll output state quantity detected as a result of the rolling motion of the vehicle (hereinafter, detected roll output). (Referred to as state quantity) to obtain a role index. In this case, the resulting rolling motion can be obtained directly from the roll angular velocity sensor RR, the suspension stroke sensor STxx, and the like. Furthermore, it is also possible to perform calculations based on various detected state quantities generated as a result of the rolling motion. For example, the roll angular velocity can be calculated from the suspension stroke speed, or the roll angle can be calculated from the roll angular velocity. Further, the lateral acceleration sensor is arranged at a predetermined distance in the vertical direction of the vehicle, and the detected roll output state quantity can be obtained from the difference between the lateral accelerations detected by the plurality of lateral acceleration sensors. Furthermore, when a rolling motion occurs, the in-vehicle lateral acceleration sensor detects the gravitational acceleration component because of the roll angle, and this phenomenon is used to calculate the lateral velocity calculated by the above-mentioned equation (1). The detected roll output state quantity can also be obtained by comparing the acceleration Gy1 with the lateral acceleration Gy detected by the lateral acceleration sensor GY.

  Next, the calculation process of the roll index RI using the roll angular velocity will be described with reference to FIG. In the initialization process of step 100 described above, the roll index is set to its initial value RIo. The initial value RIo of the roll index is set as a more stable value that tends to increase the roll so that the braking force control and the driving force control for stabilizing the rolling motion are easily performed. In addition, the roll index RI is estimated at the time of turning when a rolling motion exceeding a predetermined roll state amount is generated. In this way, since the roll index is not estimated for each turn but when it is equal to or greater than a predetermined roll state quantity, the roll index estimation error can be suppressed to a small value.

  In FIG. 15, in step 150, the roll state quantity Rst of the vehicle shown in the above [Table 1] is calculated based on the read sensor signal and communication signal. In step 151, the roll state quantity Rst is compared with a predetermined value in order to determine whether or not the roll index can be estimated with respect to the rolling motion of the vehicle. If it is determined that the roll state quantity Rst is not greater than or equal to the predetermined value, the roll index is not estimated, and therefore the roll index is not changed, and the value of the roll index in the previous control cycle is maintained.

  If it is determined in step 151 that the roll state quantity is equal to or greater than the predetermined value, the process proceeds to step 152 and subsequent steps, and the roll index is estimated. In steps 152 to 154, the roll index RI is calculated by the means shown in FIG. Then, the process proceeds to step 155, where the change from the previous roll index is performed based on the roll index RI calculated in step 154. Thus, since the roll index RI indicating the ease of appearance of the roll increase tendency of the vehicle is calculated according to the control state of the suspension control device, the roll index can be obtained with high accuracy.

  In changing the roll index RI in step 155, the roll index RI can be changed step by step without immediately changing to the calculated value. Since the estimation calculation of the roll index RI may include an error, the influence of the error is mitigated and the robustness of the estimation is improved by sequentially changing the roll index RI based on the roll index calculated for each turn. Can do.

  Next, an example of the roll index change will be described with reference to the time chart of FIG. 16. The roll index change range is limited, and the roll index RI (n) estimated this time and the roll of the previous control cycle are set. When the difference from the index RI is equal to or greater than the predetermined value Kri, the roll index is changed by the predetermined value Kri. In FIG. 16, the state in which the setting of the roll index is changed stepwise from the initial value RIo of the roll index is shown in time series. Here, the roll angular velocity is used as the roll state quantity in steps 150 and 151 in FIG. 15, and the roll index estimation calculation is performed when the absolute value is equal to or greater than Rr1.

  That is, the roll index is set to the initial value RIo, and when the first turn is performed, the first roll index is estimated. At this time, even if the roll index is estimated as RIa, the roll index is not immediately changed from RIo to RIa, but is decreased by a predetermined value Kri in a direction approaching RIa (the roll index decreases) (at time t1). . Then, in the second rolling motion, when the roll index is estimated again as RIa, the roll index is further decreased by a predetermined value Kri in a direction approaching RIa (at time t2). In this way, the roll index is changed so as to gradually approach RIa.

As another example of the change of the roll index, a predetermined ratio Wri of the difference between the roll index RI (n) estimated this time and the roll index RI of the previous control cycle is used, based on the following equation (8). The role index can also be changed.
RI ← RI-Wri · {RI-RI (n)} (8)
Here, Wri is a constant and a value smaller than 1.

  Thus, by comparing the roll index of the previous control cycle with the estimated value of the roll index of the current control cycle and changing the predetermined ratio Wri of the deviation, the influence of inappropriate estimation due to error is eliminated, The roll index can be asymptotic to its true value. In FIG. 16, the roll angular velocity is focused on as the rolling motion of the vehicle. However, as shown in FIG. 14, the roll index RI can be estimated and calculated based on the roll angle. Since the roll index RI is estimated by comparing the estimated roll angle or the estimated roll angular speed based on the lateral acceleration with the roll angle or the roll angular speed obtained as a result of the rolling motion of the vehicle, Friction conditions are eliminated and reliable estimation can be performed. Furthermore, since the estimated roll index is not changed immediately, but a change range limit value or change ratio is provided and changes are made in stages, robust estimation can be performed.

1 is a block diagram illustrating a configuration of a vehicle roll characteristic estimation device and a vehicle rolling motion stabilization control device according to an embodiment of the present invention. It is explanatory drawing which shows the relationship of the state quantity in the rolling motion of a general vehicle. It is a block diagram which classifies and shows the state quantity showing the input of rolling motion in the present invention. 1 is a configuration diagram illustrating an overall configuration of a vehicle including a rolling motion stabilization control device for a vehicle according to an embodiment of the present invention. It is a lineblock diagram showing an example of an air suspension control device and a shock absorber control device in one embodiment of the present invention. It is a block diagram which shows an example of the stabilizer control apparatus in one Embodiment of this invention. It is a flowchart which shows the process example of the rolling motion stabilization control in one Embodiment of this invention. It is a graph which shows an example of the control map containing a roll increase tendency judging standard in one embodiment of the present invention. It is a graph which shows an example of the control situation in one embodiment of the present invention. It is a graph which shows the example of a map for calculating the target braking force with respect to each wheel of a turn outside front wheel, a turn outside rear wheel, and a turn inside rear wheel based on a state quantity deviation in one embodiment of the present invention. It is a graph which shows an example of the setting map of the roll increase tendency judgment criterion at the time of failure in one embodiment of the present invention. It is a graph which shows the other example of the setting map of the roll increase tendency judgment criterion at the time of failure in one embodiment of the present invention. It is a block diagram which shows an example of the estimation calculation of the roll parameter | index in one Embodiment of this invention. It is a block diagram which shows the other example of the estimation calculation of a roll parameter | index in one Embodiment of this invention. It is a flowchart which shows the calculation process example of the roll parameter | index in one Embodiment of this invention. It is a time chart which shows an example of the change of the roll parameter | index in one Embodiment of this invention.

Explanation of symbols

SCM suspension control device M0 suspension characteristic acquisition means M1 rolling motion detection means M2 lateral acceleration detection means M3 rolling motion estimation means M4 roll index estimation means M5 roll increase tendency determination criterion setting means M6 control means M7 failure determination means M7
ECU 1 Brake system electronic control unit ECU 2 Engine system electronic control unit ECU 3 Instrument panel system electronic control unit ECU 4 Air suspension system electronic control unit ECU 5 Shock absorber system electronic control unit ECU 6 Stabilizer system electronic control unit SA Steering angle sensor GX Longitudinal acceleration sensor GY Lateral acceleration sensor YR Yaw angular velocity sensor RR Roll angular velocity sensor BRK Brake actuator BP Brake pedal AP Accelerator pedal sensor

Claims (4)

  In a vehicle roll characteristic estimation device that is mounted on a vehicle equipped with a suspension control device capable of adjusting suspension characteristics and estimates the roll characteristic of the vehicle, a suspension characteristic acquisition unit that acquires the suspension characteristic, and the vehicle that is running Rolling motion detection means for detecting the actual rolling motion of the vehicle, lateral acceleration detection means for detecting the lateral acceleration of the vehicle, lateral acceleration detected by the lateral acceleration detection means, and suspension characteristics acquired by the suspension characteristic acquisition means The rolling motion estimation means for calculating the rolling motion of the vehicle, and the vehicle according to a comparison result between the actual rolling motion detected by the rolling motion detection means and the estimated rolling motion calculated by the rolling motion estimation means. A row indicating the ease with which rolls tend to appear Roll characteristic estimation apparatus for a vehicle, characterized in that a roll-index estimation means for estimating an index.   Suspension characteristic acquisition means for acquiring the suspension characteristic in a vehicle rolling motion stabilization control device mounted on a vehicle equipped with a suspension control device capable of adjusting suspension characteristics and stabilizing the rolling motion of the vehicle during traveling; Rolling motion detection means for detecting an actual rolling motion of the vehicle while traveling; lateral acceleration detection means for detecting lateral acceleration of the vehicle; lateral acceleration detected by the lateral acceleration detection means; and the suspension characteristic acquisition means. Comparison result between rolling motion estimation means for calculating the rolling motion of the vehicle by calculating based on the obtained suspension characteristics, and the actual rolling motion detected by the rolling motion detection means and the estimated rolling motion calculated by the rolling motion estimation means Depending on the roll increase of the vehicle Roll index estimation means for estimating a roll index indicating the ease of appearance of the direction, and roll increase tendency determination reference setting means for setting a determination criterion for the roll increase tendency of the vehicle based on the roll index estimated by the roll index estimation means And a control means for performing at least one of braking force control and driving force control of the vehicle based on a roll increase tendency determination criterion set by the roll increase tendency determination criterion setting means. Rolling motion stabilization control device.   Suspension characteristic acquisition means for acquiring the suspension characteristic in a vehicle rolling motion stabilization control device mounted on a vehicle equipped with a suspension control device capable of adjusting suspension characteristics and stabilizing the rolling motion of the vehicle during traveling; Rolling motion detection means for detecting an actual rolling motion of the vehicle while traveling; lateral acceleration detection means for detecting lateral acceleration of the vehicle; lateral acceleration detected by the lateral acceleration detection means; and the suspension characteristic acquisition means. Comparison result between rolling motion estimation means for calculating the rolling motion of the vehicle by calculating based on the obtained suspension characteristics, and the actual rolling motion detected by the rolling motion detection means and the estimated rolling motion calculated by the rolling motion estimation means Depending on the roll increase of the vehicle A roll increase tendency determination reference setting means for setting a direction determination reference, and at least one of the braking force control and driving force control of the vehicle based on the roll increase tendency determination reference set by the roll increase tendency determination reference setting means And a rolling motion stabilization control device for a vehicle. Failure determination means for determining failure of the suspension control device is provided, and the roll increase tendency determination criterion setting means changes and sets the determination criterion of the roll increase tendency of the vehicle based on the determination result of the failure determination means. The rolling motion stabilization control device for a vehicle according to claim 2 or 3.

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