Robust control using adaptive LMI for permanent magnet synchronous motor

This article presents a novel data-driven adaptive LMI speed tracking control strategy for permanent magnet synchronous motors (PMSMs). To achieve precise speed servo control, the speed loop is closed by a single static state feedback acting on the rotor speed, the q -axis current and an error integrator, whose output is the q -axis voltage command itself rather than a current reference for an inner regulator. The proposed adaptive LMI-based algorithm is formulated based on LMI to compute the static feedback gain directly from measured input-state trajectories, so that the gain synthesis requires no prior knowledge of the PMSM parameters and no measurement of the load torque. Simulation results show accurate speed tracking and well-shaped transients, and indicate that the controller tolerates mismatch in the inertia, stator resistance, inductance, flux linkage, and friction coefficient, including simultaneous load variations.