Steady-hand teleoperation with virtual fixtures

We present a method for implementing "steady-hand control" on teleoperators where the master device is of the impedance type. Typical steady-hand systems are admittance controlled cooperative robots that can implement very high damping. Such systems are ideal for implementing guidance virtual fixtures, which are constraints in software that assist a user in moving a tool along preferred paths. Our steady-hand teleoperation method implements a type of admittance control law on an impedance-type master, but requires no force sensor. Combined with guidance virtual fixtures, the system results in a slave device that is precisely constrained to preferred paths. Experimental results demonstrate the desirable behavior of the system. This research is applicable to impedance-type telemanipulation systems, particularly those used in robot-assisted minimally invasive surgery.