Four-wheel steering automobile stability control system

Abstract

The invention discloses a four-wheel steering automobile stability control system which comprises an automobile body slip angle measuring device, an automobile body rotation angular speed deviation measuring device and an electronic control unit, wherein the automobile body slip angle measuring device is used for detecting a deflection angle, namely, an automobile body slip angle of the speed direction of the mass center of the automobile body relative to the longitudinal axial line of the automobile in real time; the automobile body rotation angular speed deviation measuring device is used for detecting the automobile rotation angular speed deflection between the automobile body actual rotation angular speed and the driver given rotation angular speed in real time; and the electronic control unit is used for correspondingly controlling a rear wheel rotation angle controller and a braking wheel judge and braking moment distribution controller according to signals output by the automobile body slip angle measuring device and the automobile body rotation angular speed deviation measuring device in real, wherein the braking wheel judge and braking moment distribution controller controls wheel brakes of four wheels. The four-wheel steering automobile stability control system has reasonable structure, is easy and convenient to use and operate, and can effectively improve the running stability of the automobile under limit or dangerous working conditions and improve the safety of the automobile during steering at high speed at a large turning corner on a smooth road.

Description

technical field [0001] The invention relates to the technical field of automobile steering and braking comprehensive control, in particular to a four-wheel steering automobile stability control system. Background technique [0002] The stability of the car refers to the ability of the car to maintain stable driving against disturbances such as external forces or external moments that attempt to change its driving trajectory when the driver gives the car a driving direction by manipulating the steering wheel. The quality of vehicle stability will directly affect the quality of its maneuverability. The loss of stability will often cause the driver to lose control of the vehicle, making the dynamic behavior of the vehicle unpredictable and causing serious traffic accidents. [0003] The causes of vehicle instability mainly include the following aspects: 1) Due to the load transfer of the front and rear axles and the left and right sides caused by the longitudinal and lateral ac...

AI Technical Summary

Problems solved by technology

The quality of vehicle stability will directly affect the quality of its maneuverability. The loss of stability often leads to the driver losing control of the vehicle, making the dynamic behavior of the vehicle unpredictable and causing serious traffic accidents.

[0003] The causes of vehicle instability mainly include the following aspects: 1) Due to the load transfer of the front and rear axles and the left and right sides caused by the longitudinal and lateral acceleration of the vehicle, in some cases, the vehicle can change from understeer to understeer 2) The angular velocity response of the car often lags behind the driver's manipulation of the steering wheel. When the car performs an emergency lane change, this lag will cause the vehicle to generate a relatively large yaw moment when turning , after a period of time, it will cause a larger side slip angle of the car body, so under the larger side slip angle of the car body, it is often difficult for the driver to control the vehicle and cause instability; 3) The car tires are in different friction coefficients When the road is on the road (separating the road surface), it is easy to cause a great change in the attitude of the car; in addition, the interference of the uneven road on the vehicle and the interference of the side wind will also cause the change of the attitude of the car. When the side slip angle is very large, the car may be unstable; 4) When the driver encounters an emergency, the lateral force of the tire reaches saturation due to panic and improper operation, and the car will produce a large body side deflection angle, making it impossible for the driver to steer the vehicle through further adjustments, causing instability

[0004] Through comprehensive analysis of the above reasons, it can be concluded that excessive vehicle body side slip angle and inappropriate vehicle body rotation angular velocity (understeer or oversteer) are the two main causes of vehicle instability. Reasonable control is an effective way to improve the driving stability of the car, but for the current common pure front-wheel steering cars, in dangerous situations, only relying on the driver to adjust the front wheel angle of the car through the steering wheel to ensure its stability usually has little effect , so it is necessary to add an effective auxiliary control system to improve the driving stability of the vehicle

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