Adaptive robust control of the PMSM servo system with servo and performance constraints

This paper presents a prescribed performance control scheme for an uncertain permanent magnet synchronous motor (PMSM) servo system. First, the position-tracking control goals are reformulated as servo constraints, while the prescribed tracking error performances are defined as performance constraints. Second, a modified prescribed performance function (PPF) is proposed to ensure the prescribed tracking performance, while the knowledge of the initial tracking error is unnecessary. Then, the new servo constraints are formulated by introducing the state transformation technique to incorporate the tracking error performance constraints into the servo constraints. Third, an adaptive robust constraint-following control (ARCFC) is presented to render the new servo constraints to be satisfied for the transformed system. Fourth, it is proved that the proposed ARCFC can ensure the position tracking error converges and remains in a preset bounded range. Finally, the simulation and experimental verification of the developed ARCFC are conducted.