Research On Flexible Manufacturing Equipment Based On Self-positioning Technology For Aerospace Titanium

More and more aviation titanium is used in the aircraft skin production becauseof its excellent material performance. At present, it is difficult for domestic aircraftmanufacturers to clamp and locate the skin pieces or reduce the cost during theprocessing because of skin parts’ various specifications, complex surfaces, smallquantities, and Titanium’s difficulties for pre-producing positioning holes. In recentyears, with the development of modern manufacturing industry, many newtechnologies emerge: on the one hand, some studies abroad have used flexible toolingtechnology in the manufacture of aircraft skin, but the cost is still too high; on theother hand, the workpiece positioning technology has also made certain researchresults in some special manufacturing fields. Against this background, this paperstudies and designs a set of flexible processing equipment based on self-positioningtechnology for aviation titanium. The main results are as follows:（1）Aiming at solving the existing problems in domestic aviation titaniummechanical processing, this paper proposes a flexible self-positioning processingmethod. According to the needs of different enterprises, two sets of processingprogram are proposed. And a "flexible clamping-measurement-positioning-processing-detection" integration is achieved using the flexible tooling to clampblank, the measure system to locate the position and orientation of the blank, theself-seeking system to position the blank.（2）In this thesis, the structural design of one low-cost passive sets of flexibletooling system and one active sets of flexible tooling system are achieved with themethod of multi-point positioning and vacuum clamping. And a support software system based on CATIA is developed for determining the parameters of flexibletooling support.（3）Aiming at solving the self-positioning problems in aviation titaniumprocessing, this thesis proposes a "two-tier positioning" policy based on ICP (IterativeClosest Point). Match the CAD model to point cloud at coarse matching, and matchthe point cloud to the CAD model at fine match. A policy for mining points at finematch is proposed. This paper establishes an optimization objective function ofmatching algorithm, solves the function with the method of cutting plane, and finally,validates the accuracy and reliability of positioning strategy and iterative algorithmwith the help of the simulation.