Kinematic Analysis and Simulation of Parallel Mechanism with Three Translations and One Rotation
To satisfy the application needs of the steel handling industry,a novel parallel mechanism with three translations and one rotation is proposed.Each branch of the mechanism contains the actuated limb RPR and the passive limb RPaPaR,where the passive limb contains the parallelogram joint Pa,which has closed-loop structural characteristics,giving the mechanism a large stiffness.The degrees of freedom of the parallel mechanism are analyzed using the screw theory.The position inverse solution of the mechanism is constructed by using the geometric conditions between the mechanism links and the coordinate transforma-tion,obtaining the relationship between the actuator and the position and posture of the moving platform.According to the steel handling task requirements,the segmental drive function of the moving platform is calculated using the fifth polynomial,and the trajectory planning of the end of the mechanism from the ini-tial to the target position is realized with the simulation software ADAMS,and the simulation data of the ac-tuator is consistent with its calculated data,which verifies the correctness of the mathematical model of the inverse position solution of the mechanism.The position control model of the mechanism is constructed by using the PID controller,realizing the actual position of the moving platform is consistent with the theoreti-cal position trajectory.The accessible position workspace of the mechanism is obtained and analyzed using the CAD variable geometry method,deriving the workspace distribution characteristics.
NETL
NSTL
万方数据
维普
