Research on coordinate displacement compensation algorithm based on CNC machine tools and laser displacement sensors

Abstract The aerospace industry demands increasingly stringent manufacturing tolerances for aircraft skin components, particularly regarding dimensional accuracy. During online thickness measurement of skin panels, a laser displacement sensor is mounted on a Computerized Numerical Control (CNC) machine tool to inspect panel thickness. However, insufficient motion ‐ timing precision and inter ‐ machine motion variability significantly degrade measurement accuracy and hinder broad applicability. To address these issues, this paper proposes a real ‑ time coordinate shift compensation algorithm. The algorithm processes the sensor data through a sequence of steps — machining allowance reservation, iterative compensation optimization, coordinate correction, data-point filtering, and computation of inspection-point values—to achieve accurate correction. Experimental results demonstrate that the algorithm attains a measurement accuracy of 0.025 mm and a repeatability of 0.002 mm, fully satisfying the stringent precision requirements of aerospace manufacturing.