Optimization design of eight bar mechanism of electric sofa
                                    JIA Fu yang1, QIN Bao rong1, XIE Wei1, PENG Chen chen1, WANG Zheng xing2
（1.Key Laboratory of E&M, Ministry of Education&Zhejiang Province, Zhejiang University of Technology, hangzhou 310014, China；2.Zhejiang Henglin Chair Industry Co., Ltd., Anji 313300, China）


Abstract: Aiming at the problem of the unstability of the foot rest mechanism during working process, the velocity and transmission angle of the eight bar rest mechanism were studied. The position and velocity equations of the eight bar rest mechanism were established by using kinematic theory of rod system for better stability, and the theoretical model that operated in Matlab was evaluated by the motion simulation analysis in Adams. Based on the theoretical model, the size of the rod of the foot rest mechanism was optimized by genetic algorithm with the stability of the running speed of the foot rest mechanism as goal. Then, the model parameter before and after optimization were imported into Adams to simulation analysis. The results indicate that after optimization, the speed stability of the foot rest mechanism is improved and the transmission angle is also increased.
Key words: foot rest mechanism; Adams; eight bar kinematic theory; Matlab; genetic algorithm; optimization