Research On Inspection Method Of Sheet Metal Parts Based On Three-dimensional Model

With the rapid development of the aerospace industry, the performance of theaircraft have become increasingly demanding. Sheet metal parts，as an important partof aircraft parts, whose number and variety are increasing， and shapes are morecomplex, surface quality and dimensional accuracy of shape and position requirementsare also increasing, so the aircraft sheet metal parts’ corresponding inspection putforward higher requirements. In aircraft parts manufacturing enterprises, the traditionalmeans dominant. This measures rely mainly on the experience of inspectors andinspection tools, precision,which has been unable to meet today’s inspectionrequirements. With digitization and development of photovoltaic technologies and theintroduction of the concept of three-dimensional model, digital inspection means arealso on the agenda. Also note that neither the traditional testing methods nor digitaltesting methods, all have their own inherent advantages and disadvantages. A collectionof both of their strengths and building a high-efficiency, high precision sheet metal partsof the aircraft inspection system has become a trend in order to further improve partsinspection efficiency, shorten design and manufacturing production cycle.Object of this paper is unmanned aircraft sheet metal parts and the specificcontents of study is aircraft sheet metal inspection methods and methods of planningbased on three-dimensional model. The process of planning system is mainly as follow:firstly, according to precision of sheet metal parts, from known three-dimensionaldesign models to start, parts use sheet metal design software CATIA secondarydevelopment platform CAA, extract the design parameters of aircraft parts and then usethe JAVA rules engine library about keyword analysis on the design parameters toextract the characteristic parameters of sheet metal parts and parse out thecharacteristics of the formation of a three-dimensional inspectation model, and finallycombined with aircraft sheet metal parts and test specification inspection rules as themain content of the knowledge base, rational planning of the various parts of sheetmetal parts inspection means, eventually forming a complete sheet metal inspectionplanning. For programs involving traditional inspection methods, there is a need to plana reasonable inspection sequenceand inspection tools, inspection notes, cards givenprocess part inspection, inspectors according to process card to complete inspection tasks. The program involves the digitization inspection methods, requires the use ofthree-dimensional optical device ie handheld scanner inspection parts three-dimensionalscanning to reconstruct a three-dimensional verification model parts, through athree-dimensional design models and parts alignment, fitting, contrast and othermethods processed, access to the measured part surface errors automatically generateinspection reports. Overall plan achieve parameters of the extraction sheet metal parts,surface characteristics and inspection characteristics identification, human interaction,intelligent analysis, surface reconstruction, model comparison, as well as dataprocessing and other functions based on three-dimensional model of the aircraft.This article aims to explore an application of traditional and digital ways toinspection planning techniques and application mode under the three-dimensionaldigital inspection environment, generate and publish inspection reports, back the resultsto sheet metal parts inspection system, while the sheet metal to construct a reasonableinspection planning system database storage model, inspection characteristics, testspecification, inspection rules and other data, historical data collected regularly updatedstatistical analysis process causes errors caused further process for the design andprocessing process adjustments provide fast and accurate data support.