Bionic Design and Analysis of a Multi-Posture Wheelchair

Abstract. Posture transformation is an essential function for multi-posture wheelchairs. To improve the natural motion in posture transformation that is a popular problem in the design of multi-posture wheelchairs because the current wheelchair's posture transformation mechanism cannot remain consistent between the rotation center of the wheelchair and the rotation center of the human body joints. This paper proposes a sitting–standing–lying three-posture bionic transformation mechanism for a smart wheelchair. A human–wheelchair coupling model is described and analyzed according to the biomechanical characteristics of the posture transformation of human beings and their functional requirements. Theconfiguration of the transformation mechanism is chosen by comparing thetrails of the wheelchair rotation centers and the corresponding human jointrotation centers. The kinematics of the optimized configuration are discussed in detail to obtain the most bionic motion performance using themultivariable nonlinear constraint optimization algorithm. Finally, themechanism is designed, and its posture transformation performance issimulated and verified using Adams (Automatic Dynamic Analysis of Mechanical Systems) software.