Control design of a tilting mechanism for the Uk national rotor test rig facility

Abstract

This work describes the development of a model and a controller for the tilting mechanism of the UK National Rotor Test Rig Facility (NRTRF). The rig has been designed to operate in two modes: helicopter and tiltrotor. In tiltrotor mode, the regulation of the tilt angle is required between - 20° and 90°, measured with respect to the vertical axis. In order to ensure that the tilt angle of the rig is set at the required angular position, a feedback controller is found most appropriate to address disturbances, off-sets and such like. The controller must have access to the tilt angular position and adjust the motor torque (or current) as necessary to achieve the desired position. This work describes the whole process of designing the controller, including the construction of appropriate models from open-loop input-output data. We pursue two control design approaches: classical (PID) and advanced (H?), and provide a comparison of their benefits in terms of robustness and performance via experimental results.