Fixture failure diagnosis for sheet metal assembly with consideration of measurement noise

This paper expands previously developed assembly fixture fault diagnosis methodology (Ceglarek and Shi, 1996) by considering the impact of measurement noise on the diagnostic results. The proposed solution provides a new analytical tool to address the diagnosability issue during the assembly process design stage. An evaluation of fault diagnosis index as a function of noise, fixture geometry and sensor location is presented, The index is derived from the general class covariance matrices describing tooling faults. Simulation based on the real fixture is presented to illustrate the proposed method.