Work piece processing device with servo-elastic actuator system with compliance elastic member and weight compensation elastic member

A work piece processing device, comprising:

• a tool device and a work piece holder;
• and
• a servo-elastic actuator system having simultaneous precision force and position control that moves one of the tool device and the work piece holder to the other of the tool device and work piece holder;
• the servo-actuator system including a servo-actuator, a compliance elastic member and a weight compensation elastic member disposed in a force transmission path with the compliance elastic member and the weight compensation elastic member disposed with respect to each other so that a spring force exerted by the weight compensation elastic member is opposed to a spring force exerted by the compliance elastic member and a force to sensitivity position ratio is equal to a combined spring constant that is a combination of a spring constant of the compliance elastic member and a spring constant of the weight compensation elastic member;
• a controller coupled to the servo-actuator;
• and
• the controller configured to determine a force being applied to a work piece held by the workpiece holder as the compliance elastic member is deflected based on a spring deflection of the compliance elastic member in combination with the weight compensation elastic member and simultaneously control force and position of the servo-actuator based on the combined spring constant.