ROBOTIC JOINT CONTROL

A method for limiting joint velocity of a plurality of joints of a surgical robotic system, the surgical robotic system comprising a robot having a base and an arm extending from the base to an attachment for an instrument, the arm comprising a plurality of joints whereby the configuration of the arm can be altered, the method comprising: obtaining joint states for a first group of k joints of the arm, where k>1; for each of the k joints: determining from the obtained joint state a permitted range of motion for that joint; deriving, using the permitted range of motion, a joint velocity limit for that joint; selecting the minimum joint velocity limit of the k joints to be a common joint velocity limit used to limit each of the k joints individually; and calculating drive signals for driving the k joints wherein the velocity of each of the k joints is limited using the common joint velocity limit.