Force control of a class of standard mechanical systems in the port-Hamiltonian framework

This work is devoted to a force control strategy of a class of standard mechanical systems in the port-Hamiltonian framework. First, a coordinate transformation is applied to equivalently describe the original port-Hamiltonian system in a port-Hamiltonian form which has a constant mass-inertia matrix in the Hamiltonian. Then, we show how to derive an extended port-Hamiltonian system with structure preservation which can be used for force control purposes. Furthermore, we prove that the closed-loop system is asymptotically stable via a Lyapunov candidate function. Finally, experiments results are provided to show the advantages of the force control strategy in presence of external forces.