Robotic co-manipulation with 6 DoF admittance control: Application to patient positioning in proton-therapy

The paper focuses on controlling by hand a robot carrying a patient lying down on a “couch top” located at the extremity of the end-effector. The Orion prototype, is a six Degree-of-Freedom (DoF) robotic system. The control of the robot is achieved through a home-made co-manipulated haptic device located under the couch top and operated by a paramedical assistant. This device enables the operator to move the couch top, on which the patient lies down, and within an identified operational safety space. The 6 DoF admittance control algorithm is implemented on this new robotic platform. An experimental validation has been carried out to validate the co-manipulation control of the robot. The adaptable admittance parameters have been tuned on several experiments in order to observe the mass-spring-damper equivalent behaviour and demonstrate the validity of the implemented admittance algorithm.