Bilateral Telemanipulation with Guidance Virtual Fixtures

Pseudo-admittance is introduced as a novel bilateral telemanipulation system that is designed to mimic proportional-velocity admittance control on systems where the master is an impedance-type robot. The controller generalizes to systems with slave robots of the impedance or admittance type. Pseudo-admittance uses a proxy with admittance dynamics combined with direct force feedback from the slave, resulting in unique properties that mimic admittance control and exhibit tremor attenuation and quasi-static transparency. Pseudo-admittance control has potential benefits for tasks that require better-than-human levels of precision, as well as with systems that are typically run under rate control. The controller can also be modified to include virtual fixtures that provide guidance during task execution, while leaving ultimate control of the system with the operator. Guidance virtual fixtures could be used as macros that increase both speed and precision on structured tasks that require direct human control. The properties of the system are verified through simulations and experiments. KEY WORDS—telerobotics, teleoperation, admittance control, rate control, virtual mechanism, proxy, motion scaling