Cooperative control of virtual objects over the Internet using force-reflecting master arms

Force-reflecting master arms are explored for use as haptic displays in physical therapy interventions over the internet. Rehabilitation tasks can be constructed in which both the patient and therapist can interact with a common object from distant locations. Each haptic master exerts "forces" on a virtual object which, in response, generates desired velocities for the master arm to track. A novel cooperative control architecture based on wave variables is implemented to counter the destabilizing effect of internet time-delay. The control scheme is validated experimentally using a pair of InMotion2 robots in a virtual beam manipulation task between remote sites.