Research On Multi-branch Cable Automatic Layout Design Technology For Complex Products

Cable layout design is a complex and time-consuming work in complex mechanical and electrical product development. Cable automatic layout design using computer-aided become a trend due to the informationization, light-weight, precision and optics-mechanics-electrics integration of the complex products such as aeronautics and astronautics products. The multi-branch cable layout design is more complex compared to a single cable for automatic layout design. This paper takes the astronautics complex products as the specific objects, conducts the research on the theories, key technics and implementation methods of multi branch cable automatic layout design.The studies of this dissertation focus on following aspects:(1) The features of cable layout design of complex mechanical and electrical products and the research status of domestic and foreign related fields are analyzed. The research background, significance are discussed. The existing methods used in multi branch cable and pipe path planning are summarized.(2) The problem of multi-branch cable automatic layout design is analyzed. The model of the cable wire harness is introduced and some engineering constraints are described. The overall technological process of the automatic layout design of the multi-branch cable in virtual environment is also proposed. Finally, two typical kinds of path planning algorithms are introduced.(3) According to the characteristics of the multi-branch path planning, a multi-branch cable automatic routing method by Steiner Minimal Tree and improved PRM algorithms is proposed. Firstly, solve Steiner points with constraints by Steiner Minimal Tree to determine the location of middle forked points. Then based on the basic PRM algorithm, the mixed sampling strategy based on the low dispersion and the obstacle is adopted to construct a path map covering the surface of the whole space obstacle. The shortest distance of each path is searched by A* algorithm.(4) According to the characteristics of the multi-branch structure, a multi-branch cable automatic routing method based on co-evolutionary algorithm is proposed. The approach divides the whole system of branch cable into a few single cables based on the cable harness model and every single cable represents a population; We use improved RRT algorithm to obtain initial path of every single cable, then optimize middle forked points based on the idea of co-evolution, which is affected by other single cables during its evolution, and make the branch cable routing optimized.(5) To make the research result into engineering application, cable automatic layout design system is developed. The develop background, technical way, system structure, function module, interface criterion, application method and example are expatiated.Finally, the summing-up of the whole dissertation is made, prediction of the future research and direction of relative techniques are made.