A realization of haptic training system by multilateral control

In recent years, the realization of a haptic system has been desired strongly in the fields of medical treatment and expert's skill acquisition. An integrated system design of the analysis of the interaction between a robot and the environment required for stable contact operation, an observation method of the reaction force from the environment, and the architecture of a bilateral control system are absolutely essential for acquisition and reproduction of a vivid tactile sensation. In this paper, a haptic training system is realized based on multilateral control. The law of action and reaction is attained by three robots. Bilateral control is extended, and multilateral control is introduced. Multilateral control is designed similarly as bilateral control based on modal decomposition; force is controlled in the common mode, and position is controlled in the differential mode. The scaling factors of position and force are set independently. Therefore, it is possible to change a trainer's assistant force according to a trainee's skill level. The proposed training system based on multilateral control will be a fundamental technology for the evolution of haptic devices.