A Variable Gain Nonlinear Controller for Ultrasonic Motor

The steering gear of supersonic small unmanned aerial vehicle (UAV) is directly driven by the ultrasonic motor. In order to make the steering gear meet the flight requirements of high dynamic and high positioning accuracy, a variable gain nonlinear controller is designed for the ultrasonic motor control. By dynamically changing the gain of the closed-loop control system, the fast response with large gain at the high speed and the low overshoot and high positioning accuracy with small gain at the low speed can be realized. The flight experiment shows that the controller can fully meet the requirements of the supersonic small UAV, and consequently realize the fast and stable tracking and positioning of the target points.