Nonlinear Tracking of Natural Mechanical Systems for HWIL Simulation

Abstract

Auburn University has entered into collaboration with the US Department of Defense for academic study and development of hardware-in-the-loop simulation laboratory. One aspect of this collaboration has been research into new concepts for the control of flight motion tables, a critical component in HWIL simulations.

Commonly used Proportional-Integral-Derivative (PID) controllers can suffer limitations in applications with nonlinear and multi-input/multi-output systems. To overcome these limitations, a nonlinear dynamic-inversion controller was developed. Applying Lagrange’s equations to determine equations of motion, a Lyapunov function was used to develop a globally asymptotically stable controller.

After comparing PID and dynamic-inversion controllers through multiple commanded motions and adjustments to gain, the dynamic-inversion was more stable and produces less error. Both controllers are capable of performing real-time applications.