Control charts for the on-line diagnostics of CMM performances

The quality of a production process is increasing its dependence on both the manufacturing technology, and the production control. In most applications controls are operated by relying on intelligen t instrumentation to `automatically’ pe rform the programmed checks. However, the pe rformance systems that verify the product’ s quality can de teriorate , as can the production process. This paper presents a method for the on-line ve rification of the performance of a coordinate measuring machine (CMM) using statistically based control charts. The method is automated and performed on-line during a normal measurement cycle . Some experimental results are then presented and discussed.