Tolerance analysis and evaluation of uncertain automatic battery replacement system

Considering manufacturing errors and installation errors in the automatic battery replacement system, it is necessary to analyze the uncertainty of the automatic battery replacement system to improve the efficiency and accuracy of the system. There are a few universal approaches for uncertainty analysis, such as interval analysis, probability analysis, and combination approach. This paper uses grey number theory, a relatively new method, to analyze. The analysis on the coordinates of the support points finds that the grey number theory can output a range smaller than that of the other three methods, and its results are in line with the actual situation. The grey number theory is used to analyze the coordinate position change of the support point of the automatic battery replacement device with the input error change and the driving rod angle change. The bar tolerance and error circle (installation error) existing in the system are also taken into consideration. Comparing the results produced by the case where error circle is considered and that is not, it can be seen that the influence of the error circle on the results is relatively insignificant compared with that of rod tolerance, but the influence cannot be ignored for structures requiring high precision. Therefore, the analysis of the input error percentage can yield a reasonable control range of the input error based on the grey number theory, which not only ensures the system is safe and reliable, but also is cost-efficient.