An Offset-Free Explicit Model Predictive Pressure Controller for Integrated Braking System

Integrated brake system (IBS) is gaining attention due to its superior performance and applicability in high-level autonomous vehicles. Despite its high potential, the strong coupling and nonlinearity of the IBS system present significant challenges to controller design. The precision and response speed of the controller are critical factors affecting the performance of the IBS system. This paper proposes a pressure controller based on offset-free explicit model predictive control (OFEMPC) architecture to enhance accuracy and robustness. First, the pressure-position relationship is modeled as a second-order polynomial based on experimental results. Second, the Karnopp friction model is adopted for feedforward compensation, and is optimized according to the system characteristics. Further, a disturbance observer is constructed to estimate the total disturbance, which is composed of model mismatch, time-varying parameters, and unexpected disturbances. Last but not least, an explicit model predictive controller (EMPC) is constructed. To validate the performance of the OFEMPC controller, a co-simulation platform and a bench test are conducted. The results of the simulations and experiments demonstrate that the OFEMPC improves tracking precision and disturbance suppression capability. Additionally, the real-time performance is validated on the microchip.