9522845 Ziegert A new design concept for coordinate measuring machines uses a novel parallel kinematic structure that provides five degrees of freedom for orientating the measurement probe. The structure is a hexahedron formed from two tetarahedra that share a common base. The six legs of the device are telescoping tubes that incorporate laser ball bars to measure their extension, held together by spherical magnetic joints. The redundancy of six measurements for five degrees of freedom positioning will be used for calibration and compensation for the thermal environment. The hexahedron design also promises lower mass, which means improved dynamic performance. The research issues are: assessing the accuracy and thermal stability of the structure formed by the links and magnetic joints, the actuation and delivery of laser beams for metrology through evacuated or helium filled tubes, and control and dynamic performance tests. Using self-compensation to make it thermally insensitive, this design can be moved out of temperature controlled rooms to the factory floor. Lower mass improves the dynamic response, so measurements can be made faster, lowering inspection cost. Taken together, the impact of this project will be faster feedback on dimensional attributes of mechanical parts at the process, speeding up process improvements. ***
