The wave variable method for multiple degree of freedom teleoperation systems with time delay

Time delay is a serious problem for bilateral teleoperation systems. Even a small time delay in a bilateral teleoperation system would generally degrade the system´s performance and cause instability. An important approach that guarantees stability for any fixed time delay is the wave variable method. In this paper we present some recent material dealing with teleoperation systems using wave variables. In particular, we describe a wave variable scheme based on a family of scaling matrices for multiple degree-of-freedom bilateral teleoperation system. We include a derivation of a larger family of scaling matrices that guaranteed the system remains stable for a fixed time delay. A multiple degree-of-freedom bilateral teleoperation system using the new wave variable method is simulated using a SIMULINK model. In addition, the new derivation was implemented in hardware using an Immersion joystick and a C++ program