摘要：High positioning accuracy with odometer wheel is of great importance for internal pipeline defect detection. In current research, the qualitative analysis is focused on and the accumulation characteristics of positioning errors are not shown. Based on this, the models and the accumulation characteristics of positioning errors are investigated in this paper. The errors are classified into systematic errors and random errors. Systematic errors consist of difference between actual and nominal diameters, diameter difference among wheels, and terminal error. Random errors consist of initial point error, weld error, and oversized clearance. The mathematical models of the errors are obtained by the methods of quantitative analysis and contrastive analysis. Through calculation examples, the results show the relationship of the errors and the effect of each error on total error. Diameter calibration and detection in sections are proposed to improve the positioning accuracy.
