Abstract
An electronic stability control (ESC) system improves the stability of a vehicle when it is understeered or oversteered by controlling the braking force exerted by each wheel according to a tire force characteristic. There is a tradeoff between the braking force and the lateral force. In order to improve upon a conventional ESC system, we have developed a control system that efficiently uses the regime of interest in tire force characteristic for brake control by monitoring the tire lateral force in real time. This ESC-i system works by defining a reference lateral force and estimating the actual lateral force based on the vehicle motion (e.g., lateral acceleration, yaw rate). When the actual lateral force is less than the reference value, the braking force increment is restrained to maximize the total lateral force acting on the vehicle. The control concept of ESC-i is verified by performing vehicle tests. In summary, ESC-i achieves vehicle stability and allows the vehicle to turn smoothly.
Keywords: Electronic Stability Control, Vehicle Dynamics, Tire Force Characteristic, Lateral Force