Control charts for the on-line diagnostics of CMM performances

The quality of a production process is increasing its dependence on both th e manufacturing technology, and the production control. In most application s controls are operated by relying on intelligent instrumentation to 'autom atically perform the programmed checks. However, the performance systems th at verify the product's quality can deteriorate, as can the production proc ess. This paper presents a method for the on-line verification of the perfo rmance of a coordinate measuring machine (CMM) using statistically based co ntrol charts. The method is automated and performed on-line during a normal measurement cycle. Some experimental results are then presented and discus sed.