Feedforward and Feedback Tracking Control of a 3DOF Helicopter Experiment under Input and Output Constraints

This article describes the feedforward/feedback tracking control design for a 3DOF helicopter experiment with input and state constraints. By appropriate choice of the outputs, the state constraints are interpreted as output constraints, in order to apply a newly presented feedforward control design under input and output constraints for finite-time transition problems. The fast 360-degree turn of the helicopter within a finite-time interval serves as a challenging test maneuver. The feedforward design treats the setpoint transition as a two-point boundary value problem in the input-output normal form of the system. This approach also allows to systematically account for the constraints of the helicopter. In addition, an optimal feedback controller is used to stabilize the system along the desired trajectories. The performance of the feedforward/feedback tracking control scheme is demonstrated by experimental results