Fail-safety of Automated Workpiece Inspection Systems in Production Metrology

摘要

Automated Workpiece Inspection Systems (AWIS) must fulfill ever higher requirements. At the same time, the high expenditures have to be compensated by high availability as well as high quality and quantity performance. In addition to these requirements, recently a new quality characteristic has been gaining importance, namely the fail-safety of AWIS. While the manual calibration of inspection processes is state of the art, for automated processes the question arises: Who monitors the inspection devices? The difference between automated production measurement and laboratory measurement lies in monitorability. In laboratory measurement, the operator can check the measured values for plausibility and carries out an evaluation afterwards, whereas automatic production is not capable of this "common sense" process. These influences cause the measurement uncertainty of AWIS to show larger variations. Nowadays, we face these challenges by using robust measurement systems with systematic and periodic manual monitoring and calibration. However, this method brings about a conflict between quality performance and availability of an AWIS. One possible solution for this conflict is the use of fail-safe Automated Workpiece Inspection Systems. These systems are characterized by automatic monitoring of their operability, which reduces the frequency of manual monitoring. This helps to meet the growing quality requirements and the tightened liability regulations.