Alex Beckerman and Donald Margolis
A number of distinct actuation setups exist for directional control of ground vehicles. Additive front steering allows for the controlled modification of tire-steered angle away from the driver’s input with benefits to vehicle handling and safety. Traditional electric power steering systems (EPS) allow for tunable feedback that improves steering feel and provides assistance to the driver. A bond graph model of a steering system is developed to investigate a dual-motor configuration for simultaneous additive-front and power-assist steering. The bond graph structure here helps to identify system configurations that achieve the stated system goals while not inhibiting the ability of the driver to steer the vehicle under various failure modes. Controllers are designed for both motors using the model reference approach with analytical and simulation-based results confirming the efficacy of the methods used.