Fuzzy adaptive PDF controller for motion control systems

High performance AC drives requiring good position command tracking and load regulation responses are increasingly demanded in industrial applications. Adaptive control methods that take plant disturbances suppression into account have been used to improve servo drive performance. Generally, the adaptation is achieved by using either the model reference approach or recursive plant parameter identification. Instead, this paper proposes a single self-tuning control based on supervisory fuzzy adaptation which changes the integral term of an standard PDF controller for adapting it to the plant evolution according to the dynamics of the system. The fuzzy logic adaptive strategy has been readily implemented, with very good tracking and regulation characteristics. Stability of the developed controller has been established in the Lyapunov sense, and simulations results demonstrate the robustness of the suggested algorithm in contending with varying load and torque disturbance.