Opening New Dimensions: Vehicle Motion Planning and Control using Brakes while Drifting
Tushar Goel, Jonathan Y. Goh, J. Christian Gerdes
Abstract
Autonomous vehicles should be able to maintain control in scenarios that push them beyond the limits of handling. In case of unintended rear tire force saturation while driving, the vehicle should be able to decelerate while ensuring the navigation of an obstacle free path. With that objective, this paper presents a novel architecture capable of controlling a rear-wheel drive vehicle in a drift using brakes in addition to steering and throttle. We demonstrate the existence of another dimension of drift equilibria which allow motion planning algorithms to prescribe vehicle states independently even while drifting. A tangent space analysis illustrates the transformation from an under-actuated to a fully-actuated system with the use of front-wheel braking. Minimal modifications to existing state of the art in drifting can exploit the additional actuation to significantly increase the set of feasible actions for the vehicle. The framework is then experimentally validated for two different trajectories on MARTY, an electric DeLorean drift research platform.