Research on Measuring Point Selection for Strain-Based On-Machine Estimation of Workholding States

To ensure the reliability of small-lot machining for thin-structured parts, an on-machine workholding state estimation method based on measured strain has been proposed. When applying this method to actual machining scenarios, it is necessary to select appropriate measuring points to achieve estimation accuracy. This paper proposes a method capable of systematically selecting measuring points for individual cases. First, finite element simulation was used to calculate strain values for each fixturing case. Moreover, the variations in strain values corresponding to the variated fixturing process were calculated using feasible varied fixturing conditions. Using the strain values corresponding to the feasible fixturing conditions, an evaluation criterion was applied to evaluate the candidate measuring points. The feasibility of the proposed criterion was investigated by estimating workpiece deformation using different measuring candidate points and comparing the accuracy of the estimations. In the investigation, the estimated workpiece deformation results were compared with the actual workpiece deformation. The comparison demonstrated that the proposed method can effectively identify appropriate strain measuring points.