Composite control of an automotive anti-lock braking system based on electromechanical braking

Aiming at the drawbacks of traditional anti-lock braking system hydraulic braking, such as uneven braking force and unsatisfactory braking effects, this paper proposes a composite control method for automotive anti-lock braking system based on electronic mechanical braking. First, under the premise of ensuring reasonable model simplification, a vehicle dynamics model was constructed, which consists of a slip ratio subsystem and an electronic mechanical braking subsystem. Second, in the slip ratio subsystem, based on the real-time disturbance estimation of the extended state observer, a sliding mode control based on finite-time prescribed performance backstepping was designed to make the slip ratio quickly and accurately track the expected value within the set time and provide a reference virtual braking pressure for the electronic mechanical braking subsystem. Then, in the electronic mechanical braking subsystem, an anti-lock braking system braking pressure tracking control strategy based on active disturbance rejection control was proposed to actively estimate and compensate for the unknown disturbances in the system, achieving precise tracking of the braking pressure to the reference braking pressure and improving braking performance. Finally, simulations were conducted under three conditions: dry asphalt, wet asphalt, and icy pavement. The results demonstrate that the designed control strategy enables the slip ratio to rapidly track the desired value within 0.3 s, with tracking efficiencies of 99.47%, 99.56%, and 99.87%, respectively. The braking pressure convergence errors were as low as 6.8 × 10 −9 , 3.4 × 10 −8 , and 5.4 × 10 −8 , significantly enhancing the robustness and control precision of the braking system.