Analysis of Measurement Uncertainty of Crankshaft Comprehensive Measurement Follow-up System

Abstract:
The follow-up system is one of the most important functional components for comprehensive crankshaft measurement, and its accuracy level is the most critical factor affecting the entire crankshaft measurement system. In order to improve the measurement accuracy of the follow-up system, it is necessary to carry out research on the key factors affecting the accuracy and its uncertainty. According to the principle of follow-up measurement of comprehensive crankshaft measurement, the main factors such as the geometric error of the follow-up rail, the error of the displacement sensor and the change of contact force that cause the measurement accuracy of the follow-up system are analysed. According to the uncertainty components produced by various influencing factors, the measurement uncertainty model of the follow-up system is established. Calculation examples show that the geometric error of the follower guide rail and the accuracy of the linear displacement sensor have the greatest influence on the measurement uncertainty of the follower system. The accuracy indexes of the follower guide rail and linear displacement sensor required when the uncertainty of the followup system reaches 1.5 µm and 0.5 µm are respectively given, which provide a reference for the design and development of a comprehensive crankshaft measurement follow-up system.