Estimation of clamp force in brake-by-wire systems: a step-by-step identification approach

Elimination of a clamp force sensor from brake-by-wire system designs is strongly demanded due to implementation difficulties and cost issues. In this paper a new method is presented to estimate clamp force using the motor angular position of the actuator that can be sensed by an internal resolver. The estimator is a dynamic nonlinear model that is derived from a system identification approach where frequency domain analysis is merged with nonlinear compensation. The designed estimator is able to accurately track a wide range of sinusoidal, ramp and random clamp force signals. It is particularly tolerable to high-speed cases as demanded by ABS controls. This paper is concluded with further investigation detailed that is necessary to ensure a robust clamp force estimator is developed.