Today's industrial robots are almost always programmed using a position control scheme. Typically, the robot tool follows a prescribed trajectory in space which has been pre-programmed or "teached" before run-time. Sometimes, the robot gets its reference position from a vision system, which enables it to adapt its motion to its changing environment. However, for some applications, it is more important to precisely control the force applied by the end-effector rather than controling the robots positioning. One example of this is the finishing of a machined part, as seen in the video below: