Passivity based control of hydraulic robot arms using natural Casimir functions: Theory and experiments

This paper gives a new passivity based control of hydraulic arms based on a new model using ldquonaturalrdquo Casimir functions. Not only passivity but also Casimir functions are used in the modeling and control as a new structural property. First, we refer port-Hamiltonian systems and their properties. Second, we propose two stabilization methods, a new dynamic asymptotic stabilization method and a new partial stabilization method. Third, we give a new model of hydraulic arms using Casimir functions. Furthermore, the proposed two stabilization methods are applied to this model and finally, the validity of our methods are confirmed by not only numerical simulations but also experiments even thought the bulk modulus is not identified at all.