Control of interactive robotic interfaces. A port-Hamiltonian approach
The presented monograph is based on the Ph.D. thesis of the first author which he defended at the University of Modena and Reggio Emilia in 2004 and it deals with energy based control of interactive robotic interfaces. When two physical systems interact they exchange energy and in order to control the interaction in a sensitive way, it is necessary to control this energy exchange. The port-Hamiltonian formalism provides a framework for modeling physical systems based on the concept of energy, interconnection and power ports which model the phenomena of energy storage, energy exchange and external interaction respectively. In this book, port-Hamiltonian framework is exploited both for modeling and controlling interactive robotic interfaces. Starting with the port-Hamiltonian model, it is possible to identify the energetic properties that have to be controlled in order to achieve a desired interactive behavior and it is possible to build a port-Hamiltonian controller that property regulates the robotic interface. Due to its generality, port-Hamiltonian formalism allows to deal also with complex interactive systems, both linear and non-linear. In Chapter 1, starting from the so-called behavioral approach for modeling, it is shown that the energy and the energetic interconnections, along with the internal power exchange takes place, and, the ports which power is exchanged with the external world, are the essential ingredients to model the behavior of physical systems; the mathematical object of Dirac structure is introduced and both implicit and explicit port-Hamiltonian systems are introduced. In Chapter 2 energy is exploited for control purpose and it is shown how to exploit the energetic properties of port-Hamiltonian systems to build energy based controllers that allow to solve the regulation problem for physical systems. The basics of passivity theory are presented and the link between stability of certain configuration and the shape of the energy of the physical system is illustrated. A control strategy that embeds variable structure techniques in energy based control is shown. In Chapter 3 the problem of controlling interactive robotic interfaces is introduced. An energetic analysis of interaction is provided and an intrinsically passive control strategy for interactive systems is presented; port-Hamiltonian controllers are used to shape the energetic properties of the robotic and, therefore, to achieve the desired kind of contact behavior. A port-Hamiltonian impedance is introduced and some new developments that allow to deal also with defective and anthropomorphic robots and with complex robotic interfaces as robotic hands are illustrated. An energetic model of a generic haptic interface is presented and the port-Hamiltonian formalism is used for building an intrinsically passive control scheme for haptic interfaces which allows a stable interaction with generic, both linear and non-linear, virtual environments. In Chapter 4 bilateral telemanipulation systems, that allows to interact with remote environment, are introduced and an energy based analysis is provided. Port-Hamiltonian formalism together with scattering theory are used to achieve an intrinsically passive port-Hamiltonian based bilateral telemanipulation scheme which exhibits a stable behavior both in case of contact with the remote environment and of free motion, independently of any delay. It is shown how to extend the scheme in order to passively deal with the discrete nature of the controllers and with variable delay packet switching communication channels (e.g. Internet) In Chapter 5 the problem of transparency in bilateral telemanipulation is illustrated. A framework, based on the behavioral approach, for the evaluation of transparency is presented and used to evaluate transparency of port-Hamiltonian based intrinsically passive bilateral telemanipulation schemes. Extended port-Hamiltonian systems are introduced to allow a passively preserving variation of physical parameters characterizing the port-Hamiltonian controllers used to control master and slave robots. In Appendix A, some background on the mathematical tools used in the book is provided.
scientific article; zbMATH DE number 5133929