Modeling and control of electromagnetic brakes for enhanced braking capabilities for automated highway systems

In automatic highway systems, a faster response and a robust braking system are crucial part of the overall automatic control of the vehicle. This paper describes electromagnetic brakes as a supplementary system for regular brakes. This system provides better time for emergency situations, and in general keeps the friction brake working longer and safer. A modified mathematical model for electromagnetic brakes is proposed to describe their static characteristics (angular speed versus brake torque). The performance of the modified mathematical model is better than the other three models available in the literature. To control the brakes, a robust sliding mode controller is designed to maintain the wheel slip at a given value. Simulations show that the controller designed is capable of controlling the vehicle with parameter deviations and disturbances.