一平移两转动并联运动振动筛动力学建模与精度分析

Dynamic Modeling and Precision Analysis of Parallel VibratingScreen with One-translation and Two-rotation

对单自由度一平移两转动(1T2R)并联运动振动筛进行了动力学分析。由于该机构包含2个子运动链(SKC),且其耦合度均为零,因此,首先由求得的符号式位置正解直接求解各杆件(角)速度和(角)加速度;然后,基于Newton Euler原理的序单开链法,对含两个SKC的空间并联机构进行动力学建模,计算得到该机构主动副的驱动力矩变化曲线;与利用传统Lagrange法得到的驱动力矩进行了动力学建模误差对比分析,结果表明,基于Newton Euler原理的序单开链法具有更高的动力学建模精度。本文为多回路空间并联机构高效、精确动力学建模与分析,以及该并联运动振动筛的动力学参数优化提供了理论基础。

Dynamic analysis for the one-DOF parallel mechanism(PM)vibrating screen with one-translation and two-rotation(1T2R)developed by the authors was performed.Firstly,since the PM contained two sub-kinematic chains(SKC)and its coupling degree was 0,it was easy to solve the symbolic solutions of the forward position and directly obtain the(angular)velocity and(angular)acceleration of all links.Then,the ordered single-open-chain(SOC)method based on the Newton Euler principle proposed by the author s team was used in the dynamic modeling of this spatial PM with two SKCs,and the driving torque M curve of the actuated joint of the PM was calculated.Comparing the curves obtained by Matlab programming and ADAMS simulation,the correctness of the ordered SOC method based on the principle of Newton Euler was verified.In addition,the dynamic modeling error analysis was carried out with the driving torque M obtained by the traditional Lagrange method.The results showed that the absolute error range of the ordered SOC method based on the Newton Euler principle was 33.39%smaller than the absolute error range based on the Lagrange modeling method.It was showed that the ordered SOC method based on the Newton Euler principle had higher dynamic modeling accuracy.The research result provided a theoretical basis for efficient and precise dynamic modeling of multi-loop spatial PM as well as the motor optimization,parameters optimization and dynamic optimization of the parallel vibrating screen.