A Linear Quadratic Regulator Based Speed Control for Remote-Controlled Racing Cars

This paper introduces a Linear Quadratic Regulator (LQR) based speed control for remote-controlled (RC) car racing. When it comes to RC car racing, the objective is to be the fastest by reducing the laps time. This means that the race driver model must be as fast as possible on the track while staying within the track's boundaries. In this paper, a linearized vehicle dynamics model is used to develop speed controller for regulating the car speed to the speed target which is generated based on a friction circle model. The friction circle model, which calculates the speed limit based on tyre grip and track curvature, is used to develop the speed target. The Proportional-Integral (PI) controller was also used to compare the speed control obtained by the LQR. Given that all trajectories are not equivalent in terms of time efficiency, this study of speed controllers is performed on an optimized trajectory which is a compromise between speed and distance. In comparison to a Proportional-Integral (PI) controller's performance, the speed regulated by LQR resulted in a time advantage of 1.58 seconds over four laps and a fastest lap of 25.926s on the fourth lap.