Robust Continuous Wheel Slip Control With Reference Adaptation: Application to the Brake System With Decoupled Architecture

Modern and coming generations of electric and automated vehicles are characterized by higher requirements to robust and fault-tolerant operation of chassis systems independently from driving situations and road conditions. In this regard, this paper introduces an adaptive continuous wheel slip control (WSC) developed for the sport utility vehicle equipped with a high-dynamic decoupled electrohydraulic brake system. The system architecture, mathematical formulation of the WSC and state estimator as well as the experimental WSC validation is described in this paper. The focus is given on three continuous WSC strategies based on proportional integral (PI), sliding-mode PI and integral-sliding-mode control techniques. The proposed WSC also includes the state and parameter estimator for the adaptation of the reference wheel slip depending on current road conditions and using the standard on-board vehicle sensors and extremum-seeking algorithm. Adaptability and robustness of all WSC configurations were confirmed by the road experiments performed on low- and high-μ surfaces with mandatory condition of the same controls adjustments for all test cases. Tests show an enhancement of the vehicle safety and ride quality, compared to the vehicle with the rule-based WSC control.