Control system configured to compensate for non-ideal actuator-to-joint linkage characteristics in a medical robotic system

A control system for controlling a first actuator that is mechanically coupled through a first mechanical coupling characterized by non-idealities to a first distal joint which in turn is coupled to an end effector so as to control movement of the end effector in a first degree of freedom in response to operator manipulation of an input device, the control system comprising:

• an end effector controller configured to generate a first distal joint command using an end effector command indicative of operator manipulation of an input device, and to generate a first feed forward command to compensate for residual error in a first actuator state error due to the non-ideal characteristics of the first mechanical coupling by using at least one of a friction model and a cable compliance model of the first mechanical coupling;
• a first distal joint sensor disposed proximate to a distal end of the first mechanical coupling so as to be proximate to the first distal joint relative to the first actuator to generate information of a state of the first distal joint;
• a first distal controller configured to generate a first actuator command using the first distal joint command and the state of the first distal joint;
• a first local sensor disposed proximate to a proximal end of the first mechanical coupling so as to be proximate to the first actuator relative to the first distal joint to generate information of a state of the first actuator;
• and
• a first proximal controller configured to close a first feedback loop around the state of the first actuator to ensure tracking of the state of the first actuator by generating the first actuator state error using the first actuator command and the state of the first actuator and providing the first actuator state error to the first actuator along with the first feed forward command so that the first actuator causes corresponding movement of the first distal joint through the first mechanical coupling.