Reliability optimization of location precision of extraction manipulator
LAO Ke ming1, ZENG Qing feng2
(1.Key Laboratory of E&M, Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China;
2.Zhejiang Machinery Industry Federation, Hangzhou 310009, China)


Abstract: Aiming at the problem of absolute location precision deficiency and high cost of the extraction manipulator, reliability optimization design about the manipulator was made based on the evaluating method for the reliability of the location precision. The static error model of the manipulator was set up with the application of multi body system theory, location precision was analyzed based on the Monte Carlo method and total error sensitivity of the end of the manipulator was calculated. An approximate dynamic error model of the manipulator was set up with the adoption of response surface method, and the output quantity expression was gained. Dynamic and static coupling error model was also set up through seeing the dynamic error as the deformation of the manipulator end, and with the consideration of coupling between the dynamic and static error in the practical project. Location precision optimization model was established with the location precision reliability as the constraints, minimum cost and volume as the goal, as well as the static error sources and structural parameters as the design variable; and the design variable was optimized with the NCGA II combining with the Monte Carlo method. The results indicate that actual requirement on the location precision is satisfied through the optimization; cost and volume are lowered by 15% and 7.6% respectively, which all provide the basis for the design and manufacture of the manipulator.

Key words: reliability optimization; absolute location precision; montecarlo method; dynamic error; static error