Uncertainty evaluation for dynamic identification of a micro contact probe based on the signal transmission chain analysis method

Abstract

The dynamic characteristics of a probing system directly affect the accuracy of dynamic measuring results and should be investigated comprehensively. Many methods can be used to identify the dynamic model of a probe. However, the uncertainty evaluation for the identified probe model remains a problem. A method based on signal transmission chain analysis is proposed in this paper to evaluate the uncertainties for dynamic identification of a micro contact probe. Taking a homemade micro contact probe as an example, the adaptive recursive least squares method is adopted to identify the probe model parameters according to the step input signals and the corresponding output signals of the probe. The signal transmission chain analysis method is utilized to analyse the source of uncertainties and their transmission relationships. The Monte Carlo method is employed to evaluate and combine the uncertainties of the obtained model parameters. Evaluation results are verified by experiments. The results of uncertainty evaluation can guide the compensation and improvement of the dynamic characteristics of the probing system. The proposed method can also be used to evaluate the uncertainties of dynamic identification for other sensors.