Towards a safe physical human-robot interaction for tele-operated system: Application to doppler sonography

Abstract

The use of variable stiffness actuators in robots allows to enhance the human safety criteria when both human and robot coexist in a shared workspace. We study the behavior of V2SOM, a joint variable stiffness mechanism developed by Pprime Institute, when the mechanism is adapted in the joints of a multi-DoF robot. We compare the impact forces produced by a rigid-body and the joint-flexible robot, through the dynamic model of a 7-DoF robot. We propose the robot-assisted Doppler echography as an example of application, where patient safety must be guaranteed by effectively limiting the force applied by the robot over the patient. For this purpose, we define a cartesian control approach allowing to control the displacements of the ultrasound probe carried by the robot’s end-effector. Simulation results showed the effectiveness of using the V2SOM in a multi-DoF robot, in terms of human safety.