A laser scanning posture optimization method to reduce the measurement uncertainty of large complex surface parts

Non-contact laser scanning is widely used in aircraft parts inspection and components assembly, especially for the dimensional error of complex structural parts. Careful scan path planning can greatly improve the measurement accuracy and efficiency of scanning. This paper presents a methodology to solve the design and optimization problems of scanning posture. The scanning quality is improved by reducing measurement uncertainty to obtain the optimum posture angle and spatial position for scanning. A posture coordinate system is established to obtain the posture angle deviation between the current scanning posture and the principal direction of all points in the corresponding measuring area, which quantifies the measurement uncertainty of the scanning area. The posture adjustment interval is defined according to the limit scanning envelope to search for the feasible direction and position of the scanner, and the measurement uncertainty of the scanning area is reduced by optimizing the posture angles iteratively. We demonstrate the effectiveness of the proposed method by comparing it with other posture planning algorithms.