Research On Integrated Vision And Force Alignment Technology For Micro Assembly System

In recent years,micro-electromechanical systems have been widely used in major fields of Defense Science and technology,such as aeronautics,aerospace,weapons and electronics,and micro-electromechanical products have been developing to the direction of intelligent,integrated and miniaturized.People have increasingly strict requirements for the performance index and accuracy stability of the micro assembly system.The research of micro-assembly system has also become the focus and difficulty of domestic and foreign experts and scholars.As the key technology of micro-assembly system,the alignment assembly technology directly affects the assembly accuracy index of the product.At present,although there are certain achievements in the research of micro-assembly systems in China,there is still a lack of alignment assembly equipment and instr?ments.There is still a certain gap between the service life and accuracy of the same type of product compared with Western developed countries.In view of the above problems,this paper has designed an alignment assembly system based on visual and force sense integration.Its assembly accuracy can reach micron level.It provides the theoretical basis and equipment support for solving the assembly of three-dimensional complex structures with large size span and high assembly precision.The main contents of this paper are as follows:(1)The research background and significance of the micro-assembly system were introduced.The research status and development trend of the micro-assembly system at home and abroad at the present stage were investigated.The advantages and disadvantages of the existing alignment detection technology were summarized,and the integrated alignment detection method based on "microscopic visual alignment + force feedback adjustment" was proposed.(2)In this paper,the assembly requirement of micro-scale parts in cross scale is analyzed.Based on the alignment detection method of force and vision integration,a micron level assembly system with man-machine collaboration is designed by modularization.The main functions of the assembly execution module,the visual alignment module,the force feedback module,the clamping module,the auxiliary module and the design and selection of the key equipment are introduced in detail.The general scheme and communication structure of the system control section are introduced,and the assembly sequence of the target parts and the overall assembly process flow of the parts are planned.(3)Based on the machine vision alignment method and the principle of camera geometry imaging,a coaxial alignment method of "camera imaging system + cube prism" is proposed.The calibration and error calculation of the vision alignment system are completed by the design experiment.The MIL image mosaic algorithm is used to solve the problem of large field of view and high resolution in visual alignment.The alignment detection MFC program and man-machine operation interface were programmed.The target parts were tested for alignment and test setup.The alignment detection accuracy was up to 2?m,which verified the feasibility of the alignment detection method.(4)The NANO-17 six-dimensional force sensor is used to complete the evaluation of the assembly force measurement uncertainty,and the assembly force and micro-motion platform coordinate transformation model is established.Design the experiment to collect the corresponding relationship between micro-assembly force and micro-displacement as a training sample,and use the BP neural network algorithm in Matlab toolbox to obtain the micro-force and displacement mapping model.It also completed the design of force-feedback assembly strategy and flow,and realized force-feedback adjustment,which provided a new idea and new method for force-feedback assembly of cross-scale micro-miniature parts.