JP4462045B2 - Vehicle motion control device - Google Patents

Description

  The present invention relates to a vehicle motion control device.

  An anti-lock brake system (ABS) that suppresses wheel locking during vehicle braking to ensure vehicle stability, a traction control system (TRC) that suppresses wheel slip during vehicle acceleration to ensure vehicle stability, and Devices for controlling vehicle motion such as a vehicle behavior control system (VSC: Vehicle Stability Control system) that stabilizes vehicle behavior by mitigating the side slip of wheels during vehicle turning have been put into practical use.

Patent Document 1 below describes a vehicle motion control device that changes control amounts such as antilock control, traction control, and vehicle behavior stabilization control in accordance with lateral acceleration and vertical acceleration acting on wheels. .
JP 2003-237337 A

  However, in the above apparatus, the relationship between road surface conditions and vehicle motion control has not been sufficiently considered. For this reason, the vehicle motion control may not function properly depending on the road surface condition. For example, in the anti-lock control, on a soft unpaved road such as sand (road surface having a large running resistance), the wheel is submerged in the sand tendency when the wheel is controlled to be locked as compared with the leveling road, so that the stop distance is shortened. In traction control, running on sandy roads and the like is improved by slipping the wheels compared to leveling roads because the wheels come out of the sandy ground. On the other hand, if the driving force is reduced on a sandy road in the same manner as when running on a leveling road, the running resistance is large, and there is a risk that a significant speed reduction (acceleration failure) may occur against the driver's will. Similarly, in the vehicle behavior stabilization control, if the driving force is reduced on the sandy road in the same manner as the leveling road, there is a possibility that a significant speed reduction (acceleration failure) may occur.

  On the other hand, if the wheel air pressure decreases, the ground contact area increases and the running resistance increases. Therefore, even when running on a leveling road, there is a risk of misjudging that the road is running on a sandy road with a high road resistance. There is.

  The present invention has been made to solve the above-described problems, and it is possible to determine the state of a running road surface without making an error and to execute appropriate vehicle motion control according to the determined road surface state. An object of the present invention is to provide a possible vehicle motion control device.

A vehicle motion control device according to the present invention includes a control means for controlling vehicle motion by adjusting at least one of a driving force and a braking force acting on a vehicle wheel, and a travel resistance for detecting a travel resistance during travel of the vehicle. A detecting means; an air pressure detecting means for detecting the air pressure of the wheel; and an air pressure determining means for determining whether or not the air pressure of the wheel is lowered based on a detection result of the air pressure detecting means. When the running resistance detected by the resistance detecting means is equal to or greater than the first predetermined value and the air pressure judging means determines that the wheel air pressure has not decreased, the control characteristic of the vehicle motion control is changed. It is characterized by.

  According to the vehicle motion control device of the present invention, when it is determined that the running resistance is greater than the first predetermined value and the wheel air pressure is not lowered, that is, the running resistance caused by the wheel air pressure drop is reduced. When it is determined that the vehicle is traveling on a road surface that does not increase or is small and actually has a large traveling resistance, the control characteristics of the vehicle motion control are changed. Therefore, it is possible to prevent an erroneous determination due to a decrease in the air pressure of the wheels. Therefore, it is possible to accurately determine whether or not the vehicle is actually traveling on a road surface having a large running resistance, and to appropriately determine the road surface condition that is accurately determined. It is possible to execute vehicle motion control.

  The control means determines that the running resistance detected by the running resistance detection means is equal to or greater than a second predetermined value that is greater than the first predetermined value, and that the air pressure of the wheels has decreased by the air pressure judging means. In such a case, it is preferable to change the control characteristics of the vehicle motion control.

  The maximum value of running resistance caused by the decrease in wheel air pressure is smaller than the maximum value of running resistance caused by road surface conditions such as sandy roads. For example, when the second predetermined value is set to a value larger than the maximum value of the running resistance caused by the decrease in the air pressure of the wheel, the wheel air pressure is detected when the running resistance exceeding the second predetermined value is detected by the running resistance detecting means. Even if the traveling resistance increases due to the decrease, it can be determined that the vehicle is actually traveling on a road surface with a large traveling resistance. Therefore, it is possible to accurately determine whether or not the vehicle is actually traveling on a road surface having a large running resistance, and to execute appropriate vehicle motion control according to the accurately determined road surface condition.

  The vehicle motion control device according to the present invention further includes air pressure warning means for calling a driver's attention when it is determined by the air pressure determination means that the wheel air pressure is reduced, and the control means has the above-mentioned running resistance. 2 It is preferable to prohibit the operation of the air pressure warning means when it is determined that the air pressure of the wheel is lower than the predetermined value.

  When traveling on a road surface having a large running resistance such as a sandy road, the tire air pressure is often intentionally lowered in order to improve running performance. According to the vehicle motion control device of the present invention, when the running resistance exceeding the second predetermined value is detected, and it is determined that the running resistance is actually running on a road surface with a large running resistance, the air pressure of the wheel is reduced. Even when it is determined that the air pressure has been determined, the operation of the air pressure warning means is prohibited. For this reason, the warning is issued only when it is necessary to truly call attention, so that it is possible to suppress a reduction in the effect of alerting the driver.

  In the vehicle motion control device according to the present invention, the vehicle motion control described above includes anti-lock control that suppresses wheel lock during vehicle braking, traction control that suppresses wheel slip during vehicle acceleration, and stabilizes vehicle behavior during vehicle turning. It is at least one of vehicle behavior stabilization control, and when a control means changes the control characteristic of vehicle motion control, it is preferable to change a control characteristic so that control intervention may be delayed.

  In this case, for example, in the anti-lock control, it is possible to shorten the braking distance by delaying the control intervention and controlling the wheels in a locking tendency. In the traction control, it is possible to prevent the stall and improve the running performance by delaying the control intervention and controlling the wheels in a slip tendency. Further, in the vehicle behavior stabilization control, it is possible to prevent the stall by delaying the control intervention and to suppress the decrease in the vehicle motion performance.

  According to the present invention, the control characteristic of the vehicle motion control is changed when it is determined that the detected running resistance is not less than the first predetermined value and the wheel air pressure is not lowered. Thus, it is possible to determine the situation of the road surface being traveled without error and to execute appropriate vehicle motion control according to the determined road surface condition.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts. First, the configuration of the vehicle motion control device according to the embodiment will be described with reference to FIG. FIG. 1 is a main part configuration diagram of a vehicle V equipped with a vehicle motion control device.

  The vehicle V of this embodiment uses the engine 13 as a drive source. The brake mechanism of the vehicle V can control the brake hydraulic pressure of each wheel independently. The vehicle motion control device has an anti-lock brake (ABS) function with an electronic break force distribution control (EBD), a traction control (TRC) function, and a vehicle behavior stabilization function. TRC control and vehicle behavior stabilization control are executed to control vehicle motion.

  ABS control with EBD adjusts the braking force of each wheel, in addition to the conventional ABS function that suppresses the locking of each wheel. Adjust brakes appropriately to ensure braking performance. The TRC control controls the slip ratio of the drive wheel by adjusting the output of the engine 13 and the braking force of the drive wheel. The vehicle behavior stabilization control controls yawing by adjusting the output of the engine 13 and the braking force of each wheel.

  The vehicle V includes four wheels 1FR, 1FL, 1RR, 1RL (hereinafter, the four wheels 1FR, 1FL, 1RR, 1RL may be collectively referred to as a wheel 1). Each wheel 1 has a wheel speed sensor 2FR, 2FL, 2RR, 2RL for detecting the wheel speed (hereinafter, the four wheel speed sensors 2FR, 2FL, 2RR, 2RL may be collectively referred to as a wheel speed sensor 2). It is attached.

  Also, air pressure sensors 18FR, 18FL, 18RR, and 18RL (hereinafter, the four air pressure sensors 18FR, 18FL, 18RR, and 18RL may be collectively referred to as the air pressure sensor 18) are mounted near the air valve of each wheel 1 respectively. It has been. Each air pressure sensor 18 detects the air pressure of each wheel 1 (tire) and transmits the detection result to the air pressure receiver 17. That is, each air pressure sensor 18 functions as air pressure detecting means.

  A brake disc 3 is attached to each wheel 1. A brake caliper 4 incorporating a brake pad and a wheel cylinder is attached to each brake disk 3. Each wheel cylinder is connected to a hydraulic circuit 6 via a brake pipe 5. Each wheel cylinder is also connected to a master cylinder 7 via a brake pipe 5 and a hydraulic circuit 6.

  During normal braking, when the brake pedal 8 is operated by the driver, the pressure in the master cylinder 7 rises, and this pressure rise is transmitted to the wheel cylinder via the brake pipe 5 and the hydraulic circuit 6 so that the pressure in the wheel cylinder is increased. Pressure increases. When the hydraulic pressure in the wheel cylinder is increased, the brake pad is pressed against the brake disc 3, and each wheel 1 connected to the brake disc 3 is braked by the frictional force.

  The hydraulic circuit 6 has a hydraulic pump, an electromagnetic valve, and the like. At the time of ABS control that controls braking force during vehicle braking and suppresses the locking of the wheel 1, the brake pedal 8 is operated to reduce or maintain the brake hydraulic pressure in the wheel cylinder that is raised by controlling the electromagnetic valve. The braking force for each wheel 1 is reduced or maintained. By these controls, the braking force for each wheel 1 is adjusted, and the lock of the wheel 1 is suppressed. That is, the brake disc 3, brake pad, wheel cylinder, brake caliper 4, brake pipe 5, hydraulic circuit 6 and the like function as control means.

  Also, during TRC control, the brake hydraulic pressure increased by the hydraulic pump of the hydraulic circuit 6 is controlled by the electromagnetic valve and transmitted to the wheel cylinder in the brake caliper 4 to be cut off, and the braking force for each drive wheel 1FR, 1FL is controlled. Increase or maintain Further, the pressure in the wheel cylinder for each drive wheel 1FR, 1FL can be reduced by controlling the electromagnetic valve. With these controls, the braking force for each of the drive wheels 1FR and 1FL is adjusted, and the slip of the drive wheels 1FR and 1FL is suppressed.

  During vehicle behavior stabilization control, the electromagnetic valve of the hydraulic circuit 6 is controlled to transmit the brake hydraulic pressure increased by the hydraulic pump to the wheel cylinders of some of the wheels 1 to increase the yaw moment. Note that the pressure in the wheel cylinder can be maintained or reduced by controlling the electromagnetic valve. The behavior of the vehicle V is stabilized by the generated yaw moment. Further, during vehicle behavior stabilization control, the vehicle speed itself may be lowered using such a brake mechanism.

  The brake system used in this embodiment is a disc brake system, but may be a drum brake system or the like. The hydraulic circuit 6 is connected to a vehicle motion control computer (ECU) 9 that controls the motion state of the vehicle. The hydraulic pump and electromagnetic valve of the hydraulic circuit 6 are driven by the vehicle motion control ECU 9. Wheel speed sensors 2FR to 2RL are also connected to the vehicle motion control ECU 9. The vehicle motion control ECU 9 is responsible for ABS control including EBD control, TRC control, and brake control in vehicle behavior stabilization control.

  The vehicle motion control ECU 9 is also connected to a longitudinal acceleration sensor 10, a lateral acceleration sensor 11, a steering angle sensor 15, a yaw rate sensor 16, and the like. The vehicle motion control ECU 9 executes vehicle behavior stabilization control based on the outputs of these sensors and the wheel speed sensor 2. Further, the vehicle motion control ECU 9 calculates the estimated vehicle body speed necessary for ABS control and TRC control, the slip ratio (amount) of each wheel, and the like based on the output of the wheel speed sensor 2 and the output of the longitudinal acceleration sensor 10.

  The vehicle motion control ECU 9 is also connected with a pneumatic receiver 17 and a pneumatic warning light 19. The air pressure receiver 17 receives the air pressure information of each wheel 1 output from the air pressure sensors 18FR to 18RL, and outputs the received air pressure information to the vehicle motion control ECU 9. The vehicle motion control ECU 9 determines whether or not the air pressure of the wheel 1 has fallen below the appropriate range based on the air pressure information input from the air pressure receiver 17, and the air pressure of any wheel 1 is within the appropriate range. When it is determined that the air pressure has decreased below, the air pressure warning light 19 arranged in the instrument panel or the like is turned on (or flashes), and the driver is informed that the air pressure of any wheel 1 has decreased. Is notified. That is, the vehicle motion control ECU 9 functions as air pressure determination means, and the air pressure warning light 19 functions as air pressure warning means.

  Further, the vehicle motion control ECU 9 calculates the estimated wheel acceleration based on the engine torque, the gear stage, and the like, calculates the actual wheel acceleration based on the output of the wheel speed sensor 2, and calculates the estimated wheel acceleration and the actual wheel acceleration. The road running resistance is detected from the degree of deviation. That is, the vehicle motion control ECU 9 also functions as a running resistance detection unit.

  The vehicle motion control ECU 9 is also connected to an engine control computer (ECU) 12. The engine control ECU 12 comprehensively controls the engine 13 and controls injection amount (air-fuel ratio) control and ignition timing control.

  The vehicle motion control ECU 9 and the engine control ECU 12 control the slip ratio by adjusting the output of the engine 13 (the driving force of the drive wheels) during TRC control. The output adjustment of the engine 13 is performed by controlling the intake air amount and the fuel injection amount. The throttle valve of the engine 13 is a so-called electronically controlled throttle valve, and the throttle valve opening can be arbitrarily controlled by a throttle motor. Sensors and actuators necessary for this control are connected to the engine control ECU 12. For example, in addition to the throttle motor described above, a throttle position sensor and a rotation speed sensor that detect the throttle valve opening are also connected to the engine control ECU 12. The whole mechanism attached to these engines 13 also functions as a control means.

  Further, the vehicle motion control ECU 9 and the engine control ECU 12 adjust the output of the engine 13 (the driving force of the drive wheels) and control the yawing by controlling the output of the engine 13 during the vehicle behavior stabilization control. As described above, the output adjustment of the engine 13 is performed by controlling the intake air amount and the fuel injection amount.

  The engine control ECU 12 also controls the operation of a transmission 14 provided along with the engine 13. The engine control ECU 12 can detect the gear stage of the transmission 14 and change the gear stage. It is also possible to change the gear stage of the transmission 14 during vehicle behavior stabilization control. The vehicle motion control ECU 9 is also connected with a steering rudder angle sensor 15 that detects a steering amount of a steering wheel (not shown). The steering rudder angle sensor 15 detects the steering rudder angle as one of information amounts indicating the state of the vehicle V in the vehicle behavior stabilization control. The detected steering angle can be reflected in the vehicle behavior stabilization control.

  Here, as described above, the vehicle motion control ECU 9 and the engine control ECU 12 cooperate to perform TRC control and vehicle behavior stabilization control. These ECUs 9 and 12 are stored in memory by a microprocessor that performs calculations, a ROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, and a battery. It has a backup RAM and the like inside.

  Next, operation | movement of a vehicle motion control apparatus is demonstrated using FIG. FIG. 2 is a flowchart showing a processing procedure of vehicle motion control by the vehicle motion control device. This process is performed by the vehicle motion control ECU 9, and is repeatedly executed at a predetermined timing from when the power of the vehicle motion control ECU 9 is turned on to when it is turned off.

  In step S100, it is determined whether sensors and actuators related to ABS control (including EBD control), TRC control, and vehicle behavior stabilization control for controlling the motion of the vehicle V are valid. If these sensors are not valid and step 100 is negative, ABS control, TRC control, and vehicle behavior stabilization control are not performed, and the process exits the flowchart of FIG. On the other hand, if the sensors are valid and step 100 is affirmed, the process proceeds to step S102.

  In step S102, the degree of divergence between the estimated wheel acceleration calculated based on the engine torque, the gear stage, and the like and the actual wheel acceleration calculated from the outputs of the wheel speed sensors 2FR to 2RL and the longitudinal acceleration sensor 10, that is, the road surface A determination is made as to whether the running resistance is greater than or equal to a first predetermined value. As shown in FIG. 3, the first predetermined value is smaller than the maximum value of the running resistance caused by the decrease in the air pressure of the wheel 1, and is a value that can distinguish a normal leveling road from a sandy road or a deep snow road. Set to

  Here, if the degree of deviation between the estimated wheel acceleration and the actual wheel acceleration is less than the first predetermined value, that is, if it is determined that the vehicle is traveling on a normal leveling road with a low running resistance, the normal state is determined in step S108. The vehicle motion control is performed. On the other hand, when the degree of deviation between the estimated wheel acceleration and the actual wheel acceleration is greater than or equal to the first predetermined value, that is, when it is determined that the vehicle is traveling on a sandy road or a deep snow road with a large running resistance, the process proceeds to step S104. Will migrate.

  In step S104, it is determined whether or not the air pressure warning lamp 19 is lit, that is, whether or not the air pressure of the wheel 1 has fallen below the appropriate range. If the air pressure has fallen below the appropriate range, the process proceeds to step S106. On the other hand, when the air pressure is within the appropriate range, the process proceeds to step S112.

  If it is determined that the air pressure of the wheel 1 has decreased, in step S106, whether or not the degree of deviation between the estimated wheel acceleration and the actual wheel acceleration, that is, the running resistance of the running road surface is equal to or greater than a second predetermined value. Judgment is made. As shown in FIG. 3, the second predetermined value is set to a value that is slightly larger than the maximum value of the running resistance caused by the decrease in the air pressure of the wheel 1, and thus a value that is larger than the first predetermined value.

  Here, if the degree of deviation between the estimated wheel acceleration and the actual wheel acceleration is less than the second predetermined value, it is determined that the increase in running resistance is due to a decrease in air pressure, and normal vehicle motion control is performed in step S108. Done. On the other hand, when the degree of deviation between the estimated wheel acceleration and the actual wheel acceleration is greater than or equal to the second predetermined value, it is determined that the vehicle is actually traveling on a sandy road, a deep snow road, or the like with a large running resistance, and in step S110, the pneumatic warning light 19 Turns off.

  Subsequently, in step S112, the control characteristics are changed so as to delay intervention of ABS control, TRC control, and vehicle behavior stabilization control. More specifically, the target slip ratio or the target slip amount in the ABS control is set to a larger value than in the normal time. For this reason, in the ABS control while traveling on a road surface having a large traveling resistance such as a sandy road or a deep snow road, the wheel 1 is controlled to be locked more easily than when traveling on a normal road surface, and the braking distance is shortened.

  Further, the target slip ratio or the target slip amount in the TRC control is set to a larger value than that in the normal time. For this reason, in TRC control while traveling on a road surface having a large traveling resistance such as a sandy road or a deep snow road, the wheel 1 is controlled to slip more easily than when traveling on a normal road surface, thereby improving running performance and suppressing stall. Figured.

  Furthermore, the deviation width between the target yaw rate and the control intervention yaw rate value in the vehicle behavior stabilization control is set to be larger than normal. As a result, the control is not started until the deviation of the actual yaw rate from the target yaw rate becomes larger, so that the control intervention timing is delayed from the normal time. For this reason, the deterioration of the vehicle motion performance due to the decrease in the vehicle speed is suppressed.

  According to this embodiment, when it is determined that the difference between the estimated wheel acceleration and the actual wheel acceleration is greater than or equal to the first predetermined value and the air pressure of the wheel 1 is within the appropriate range, that is, the air pressure of the wheel 1. When it is determined that the vehicle is traveling on a road surface where there is no or small increase in running resistance due to the decrease and the running resistance is actually large, the control characteristics are changed so as to delay the intervention of the vehicle motion control. Therefore, an erroneous determination due to a decrease in the air pressure of the wheel 1 can be prevented, so that it is accurately determined whether or not the vehicle is actually traveling on a road surface with a large running resistance, and appropriate according to the accurately determined road surface condition. Vehicle motion control can be executed.

  More specifically, in the ABS control, the braking distance can be shortened by delaying the intervention of the control and controlling the wheels in a locking tendency. In the TRC control, stalling can be prevented and running performance can be improved by delaying control intervention and controlling the wheels in a slip tendency. Further, in the vehicle behavior stabilization control, it is possible to prevent the stall by delaying the control intervention and to suppress the decrease in the vehicle motion performance.

  According to the present embodiment, the second predetermined value is set to a value that is larger than the maximum value of the running resistance caused by the decrease in the air pressure of the wheel 1. Therefore, when a travel resistance exceeding the second predetermined value is detected, it is determined that the vehicle is actually traveling on a road surface with a large travel resistance even when the air pressure of the wheel 1 is reduced to an appropriate range or less. be able to. Therefore, it is possible to accurately determine whether or not the vehicle is actually traveling on a road surface having a large running resistance, and to execute appropriate vehicle motion control according to the accurately determined road surface condition.

  When traveling on a road surface having a large running resistance such as a sandy road, the tire air pressure is often intentionally lowered in order to improve running performance. According to the present embodiment, when the traveling resistance exceeding the second predetermined value is detected and it is determined that the traveling resistance is actually traveling on a road surface with a large traveling resistance, the air pressure of the wheel 1 is decreased. Even when it is determined, the air pressure warning lamp 19 is turned off. Therefore, the air pressure warning lamp 19 is turned on only when it is necessary to truly call attention, so that it is possible to suppress a reduction in the alerting effect for the driver.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, detection of a decrease in air pressure is not limited to a method using a pressure sensor, and other detection methods may be used. For example, since the rotation speed of the wheel increases when the wheel air pressure decreases, it is possible to determine the decrease in air pressure based on the wheel speed. Further, the degree of delaying the intervention of vehicle motion control such as ABS control and TRC control may be varied according to the magnitude of the running resistance.

  In the above-described embodiment, the vehicle travels on the road surface based on the degree of deviation between the estimated wheel acceleration calculated based on the engine torque, the gear stage, and the like and the actual wheel acceleration calculated from the outputs of the wheel speed sensor 2 and the longitudinal acceleration sensor 10. Although the resistance is detected, the method of detecting the running resistance is not limited to the above embodiment. For example, the running resistance can also be detected based on the wheel speed estimated from the engine speed and the gear speed ratio (gear stage) and the actual wheel speed detected by the wheel speed sensor 2. Further, the running resistance may be detected based on the vehicle body lateral acceleration estimated from the steering angle and the actual lateral acceleration detected by the lateral acceleration sensor 11. Further, the running resistance can be detected based on the hydraulic pressure (estimated longitudinal acceleration) of the master cylinder 7 and the actual longitudinal acceleration detected by the longitudinal acceleration sensor 10. In the case of this method, it is preferable to perform correction using a slope gradient.

  Although a plurality of examples have been given as detection methods for running resistance, the running resistance may be detected only by any one of the detection methods, or two or more detection methods may be used in combination. In addition, a method for detecting a running resistance may be selected depending on a running state such as start acceleration, steady running, turning or braking.

  In the above embodiment, the vehicle motion control device executes the ABS control, the TRC control, and the vehicle behavior stabilization control to control the vehicle motion. However, only one control may be executed. The above control may be executed in combination.

It is a principal part block diagram of the vehicle carrying the vehicle motion control apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the vehicle motion control by the vehicle motion control apparatus which concerns on embodiment. It is a figure which shows the relationship between the 1st predetermined value, the 2nd predetermined value, running resistance at the time of air pressure fall, and running resistance at the time of sandy road driving.

Explanation of symbols

  1FR, 1FL, 1RR, 1RL ... Wheels, 2FR, 2FL, 2RR, 2RL ... Wheel speed sensor, 3 ... Brake disc, 4 ... Brake caliper, 5 ... Brake piping, 6 ... Hydraulic circuit, 7 ... Master cylinder, 8 ... Brake Pedal, 9 ... Vehicle motion control ECU, 10 ... Longitudinal acceleration sensor, 11 ... Lateral acceleration sensor, 12 ... Engine ECU, 13 ... Engine, 14 ... Transmission, 15 ... Steering angle sensor, 16 ... Yaw rate sensor, 17 ... Air pressure reception 18FR, 18FL, 18RR, 18RL ... Air pressure sensor, 19 ... Air pressure warning light.

Claims (4)

Control means for controlling vehicle motion by adjusting at least one of driving force and braking force acting on the wheels of the vehicle;
Travel resistance detection means for detecting travel resistance during travel of the vehicle;
Air pressure detecting means for detecting the air pressure of the wheel;
Air pressure determination means for determining whether or not the air pressure of the wheel is lowered based on the detection result of the air pressure detection means,
When the running resistance detected by the running resistance detecting means is greater than or equal to a first predetermined value and the air pressure judging means determines that the air pressure of the wheels has not decreased, the control means A vehicle motion control device characterized by changing control characteristics of motion control.   The control means is such that the running resistance detected by the running resistance detecting means is equal to or greater than a second predetermined value that is greater than the first predetermined value, and the air pressure of the wheel is reduced by the air pressure determining means. The vehicle motion control device according to claim 1, wherein when it is determined, the control characteristic of the vehicle motion control is changed. An air pressure warning means for alerting the driver when it is determined by the air pressure determination means that the air pressure of the wheel is lowered;
The control means prohibits the operation of the air pressure warning means when it is determined that the running resistance is equal to or greater than the second predetermined value and the air pressure of the wheel is reduced. The vehicle motion control device according to claim 2. The vehicle motion control is at least one of anti-lock control that suppresses the lock of the wheel during vehicle braking, traction control that suppresses the slip of the wheel during vehicle acceleration, and vehicle behavior stabilization control that stabilizes the vehicle behavior when the vehicle turns. And
The said control means changes the said control characteristic so that control intervention may be delayed, when changing the control characteristic of the said vehicle motion control, The control characteristic of any one of Claims 1-3 characterized by the above-mentioned. Vehicle motion control device.

Images