Abstract
To realize ultra precise machining or measurement, a machine system generating accurately relative motion between its tool and the workpiece is required as well as the accuracy improvements of each element of the machine. This paper proposes a machine system using a compensation device for 6-degree-of-freedom (6-DOF) motion errors between the tool and the workpiece. A hexapod-type parallel mechanism installed between the tool spindle and the surface plate is passively actuated by a conventional machine. Then, the parallel mechanism measures the 6-DOF motions regardless with temperature fluctuation and external forces because the mechanism has a compensation system for elastic and thermal errors of the joints and the links. Therefore, the tool position and orientation are compensated by using the measured 6-DOF errors. This paper describes the conception and the fundamentals of the system. Moreover, a passively extensible strut with a compensation device for the joint's errors was tested.
