Enhancing Regenerative Energy Capture in Electric Vehicle: Braking Performance through Integral Sliding Mode Control

Abstract

<div>This article focuses on the development of an active braking control system tailored for electric vehicles. The essence of this system lies in its ability to regulate the slip coefficient to optimize traction during braking, thereby maximizing energy recuperation. In the context of the simulation on enhancing regenerative energy capture in electric vehicles, the use of integral sliding mode control (ISMC) as an alternative for regulating braking performance can be understood through a comparison of two key output variables in braking control systems: wheel deceleration and wheel slip. Traditionally, wheel deceleration has been a controlled variable in braking systems, and it is still utilized in some anti-lock braking systems (ABS). It can be easily measured using a basic wheel encoder. However, the dynamic performance of wheel deceleration control may suffer when there are rapid changes in the road surface. On the contrary, regulating wheel slip offers high robustness from a dynamic perspective. Despite its robustness, accurately measuring wheel slip poses a challenge as it necessitates estimating the vehicle speed. Nonetheless, despite this challenge, controlling wheel slip remains the most suitable option for designing braking controllers that can adapt to variations in road surface conditions. Therefore, integrating ISMC into the braking system as an alternative enables more effective regulation of wheel slip, enhancing the overall performance and resilience of the braking system, which is particularly crucial in electric vehicles where optimizing regenerative braking is a significant concern.</div> <div>The article explores the theoretical dynamics of electric vehicle braking maneuvers and introduces the concept of an ISMC for managing the slip coefficient. Utilizing a robust control law in conjunction with this controller guarantees the exponential convergence of slip error. Afterward, we explore the visualization and simulation of the braking process performed by the ISMC, as well as the storage of the recovered energy in a supercapacitor system using MATLAB/Simulink.</div>