A medical robotic system has a robot arm holding an instrument for
performing a medical procedure, and a control system for controlling
movement of the arm and its instrument according to user manipulation of
a master manipulator. The control system includes at least one joint
controller that includes a controller having programmable parameters for
setting a steady-state velocity error and a maximum acceleration error
for the joint's movement relative to a set point in response to an
externally applied and released force.