Research Of 3-dimensional Spatial Geometrical Parameter Composite Measuring Key Technology

With the rapid development of contemporary technology, verification and calibration of high precision parts are more and more important; especially verification of war industry products is related with national defense. This topic is from National Defense Metrology"the eleventh five-year plan"of COSTIND (No. B20301118), this project aims to research on a composite CMM (Coordinate Measurement Machine) which combines contact measurement, laser measurement and camera measurement, to make sure the high precision verification of all kinds Special Gauge, geometry size of special test equipment, form and position errors, angles, to improve the efficiency of measurement work, as a result, it will meets the needs of war industry products'research, development and produce.The subject is a sub-subject of the project, mainly referring to some key technology of three-dimensional spatial geometrical parameter composite measuring: deep research of design and standardization of the composite probe, path planning, form and position error evaluation, proposed suitableand feasible solution based on those key technologies, improved the accuracy and speed of composite Measuring.Fist of all, this paper analyzes the trend and development in China and abroad of this area, researches on the general structure of composite CMM, makes summary and conclusion on the current situation and trend of CMM multi-sensor measurement, determines the main research contents of this paper.The mathematical model of composite CMM is studied. The various geometric errors transfer coefficient and synthesis method are given by considering the motion lines displacement error and angular displacement error of X, Y, Z three direction; The influence of various errors on the mathematical model of CMM is discussed; The mathematical model of rotary index table is established; Based on the characteristics of composite measure, the coordinate conversion relation between non-contact measurement head and contact measurement head is established, lays the foundation of multi-sensor composite measure.Standardization of contact probe, non-contact probe and unification standardization of composite probe is researched deeply. The paper calibrates the contact probe by standard ball fitting method based on least square method, calibrates camera by Tasi two-step approach, and designs a new calibrate approach based on first-order radial distortion model; realizes multi-probe unification standardization.According to the characteristics of composite measuring methods, this paper redefines the elements of the measurement path, designs multi-sensor measurement path rules, and establishes its basic mathematical model. After the work piece loading and sampling points, we uses the improved genetic algorithm to create generate path, uses a simple bounding box detect path, and rebuilds the collision path to achieve collisions circumvent, finally uses the simulation system based on the OpenGL realize the path planning.The paper discusses on the definition and assessment method of form and position errors, establishes evaluation models of the minimum zone spatial straightness error and sphericity error, designs two improved buzzers algorithms: NABC (Improved Artificial Bee Colony Algorithm based on Niche Technique) and DABC (Double-quick Artificial Bee Colony Algorithm), evaluates spatial straightness error uses the former, and evaluates sphericity error uses the latter. The experimental result shows these algorithms have conquer the field, and have a good stability and accuracy.