Kinematic modeling and simulation of a 5-DOF hybrid mechanism for active vibration isolation

Vibration generated by road bumps can cause secondary injury to patients. The risk of secondary injury can be significantly reduced by attaching an active suspension system to isolation medical beds. In this paper, a five DOFs (degree of freedoms) hybrid mechanism is designed by combining a 3-P(UU)<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> mechanism and a 2-PUS mechanism through a universal joint, leading to 3T2R movement capabilities to reduce the vibration. The kinematic models are firstly established to evaluate the displacement, velocity and acceleration of the hybrid mechanism. On this basis, a typical trajectory is planned to simulate the movement capabilities of the mechanism by using the trapezoidal acceleration curve motion law. Finally, the effectiveness of the kinematic models is verified by compared the results with those simulated by SolidWorks. The research results of this paper provide a solid foundation to the dimensional synthesis of the hybrid mechanism.