Oscillation annealing and driver/tire load torque estimation in Electric Power Steering systems

The paper presents several aspects of modeling, observation and control towards a new generation of Electrical Power Steering(EPS) systems. In particular we design an optimal control to reject oscillations of the steering column, then we device a new observer to estimate the internal state variables of the steering column, the driver applied torque (steering wheel torque), and the load torque (tire/ground contact friction). Finally, we also revisited the LuGre tire dynamic friction model by improving the transient behavior between the sticking phases and the dynamic ones. Simulation of the proposed control and observer are shown at the end of the paper using the improved LuGre-tire friction model.