Coordinated lateral and longitudinal vehicle dynamics control of a scale RC vehicle

This paper addresses the design, implementation and validation of a coordinated lateral and longitudinal dynamics control for a racing four-wheel driven RC vehicle. The coordination is achieved hierarchically: a wheel slip control loop stabilizes the fastest longitudinal dynamics, so that the outer lateral dynamics control can rely on non-saturated tires. Designing a wheel slip controller on a scale model requires the estimation of the wheel slip using a reduced set of sensors. The issue of estimating the wheel slip on such a small vehicle is addressed using a complementary filter. The presence of the inner wheel slip control enables the use of a simple gain-scheduled yaw-rate controller to stabilize the yaw rate dynamics and make the yaw rate gain velocity independent. The combined longitudinal and lateral controller is experimentally tested, using both repeatable tests with precomputed inputs and human-in-the-loop tests. The experimental results indicate that the controller is able to extend the operating envelope of the vehicle yielding an easier to operate vehicle.