Patent ID: 11992285

Abstract:
A robotic system comprises two robots and a control unit. Each robot has a base and an arm extending from the base to an attachment for an instrument. Each arm comprises a plurality of joints whereby the configuration of the arm can be altered. Each robot comprises a driver for each joint configured to drive the joint to move, and position and torque sensors. The control unit controls the drivers in dependence on inputs from the sensors. The control unit: determines the gravitational torques on the joints of the arms of the robots in the arm configurations indicated from the inputs from the position sensors; from the inputs from the torque sensors and the determined gravitational torques, determines residual torques on the joints of the arms of the robots in the indicated arm configurations; calculate a candidate force for each arm which when applied to that arm would cause the determined residual torques; and determines a collision if a candidate force on the arm of the first robot balances an opposing candidate force on the arm of the second robot.