ROBUST MULTI-OBJECTIVE IMPEDANCE CONTROL DESIGN FOR ELECTRIC POWER STEERING SYSTEMS: PRELIMINARY RESULTS

摘要

This paper is concerned with robust impedance shaping control for electric power steering (EPS) systems. The analysis here presents robust stability conditions for both sector-bounded and passive uncertainties. A 2-DOF controller formed of static output feedback (SOF) gains and a sector-bounded nonlinear-ity is proposed for the EPS closed loop system. The controller employs torque-feedback inner loop and an outer impedance shaping controller. The controller gains are synthesized via a multi-objective optimization involving nonlinear matrix inequality constraints. An iterative algorithm combining both semi-definite programming (SDP) and genetic algorithms (GA) is implemented to find the (sub)optimal controller gains.