Gauss's principle and tracking control of underactuated mechanical systems

Gauss's principle of least constraint is used to derive equations of motion. The principle is then used to motivate a template for the closed loop of the (tracking) controlled system. The control law arises from minimization of the distance between the controlled model and the template in the sense of least constraint. The control template is derived and analysed for the example of a free rigid body. This leads to quite natural formulations of its controlled inertia, damping and stiffness. This template is then used to compute a controller for a quadcopter, an underactuated system. A simulation result for an aerobatic maneuver demonstrates quite good performance of the proposed controller even though there is no formal proof of stability. Copyright (C) 2021 The Authors.