Research and verification of the logic threshold self-adjusting control method for ABS

Independently developing anti-lock braking system (ABS) is the basis of mastering the active dynamic control technology of vehicle chassis. According to the experimental data and the logic threshold control method widely used in the industrial ABS, the impact on ABS control of every logic threshold is analyzed and the basic rules of calibrating the logic thresholds is established. By borrowing the idea from the self-tuning regulator in adaptive control, a logic threshold self-adjusting algorithm is presented. The algorithm identifies the optimal brake slip ratio of the road and calculates the reference speed on-line. The main logic thresholds are adjusted automatically according to the error between the wheel slip ratio and the optimal slip ratio in order to improve the control performance. The control parameters are calibrated and the control performance of the self-adjusting algorithm is verified by road tests under various conditions. The test results indicate that the presented logic threshold self-adjusting algorithm overcomes the influence of different factors, such as road adhesion coefficient, speed and load, on the ABS, thereby the optimal ABS control under every condition is realized. The developed ABS has good control effect and meets the development requirement. It provides a foundation for ABS industrialization.