基于并行计算的平面可调七杆机构动力学解析模型研究

Analytical dynamic model for planar adjustable seven-bar mechanisms based on parallel calculation

基于运动学分析、凯恩动力学方程及数字-符号法,提出采用并行计算建立平面可调七杆机构动力学解析模型的方法,并研究了构件杆长及惯性参数变化对驱动力/力矩的影响。利用封闭矢量法对平面可调七杆机构进行运动学分析,得到各构件的速度和加速度表达式;将独立广义坐标、杆长及惯性参数作为符号量,其余参数处理为数值量,导出动力学解析模型的数字-符号表达式,并构造了解析模型的并行算法。由于动力学模型及实时代码优化是离线建立的,并且采用并行计算结构,减少了在线计算时间,从而为实时控制打下了基础。给出的仿真实例证明了此方法的有效性。

Analytical dynamic model for planar adjustable seven-bar mechanisms is established based on kinematic analysis,Kane dynamic equation,numeric-symbolic approach and parallel calculation.The influence of lengths and inertia parameters of links on driving force/torque are also studied.The closed vector approach is applied in the kinematical analysis of planar adjustable seven-bar mechanisms and expressions of velocity and acceleration of links are obtained.Then the numeric-symbolic expressions of the analytical dynamic model are derived in which lengths and inertia parameters of links as well as generalized coordinates are expressed as symbols,the other variables as numeral,and a parallel algorithm is also proposed.The procedures of dynamic modeling and real-time code optimization can be performed off-line and parallel calculation structure is adopted,therefore on-line calculation time can be reduced greatly,which is of advantage to real-time control of mechanisms.The examples of dynamic simulation showed that the method is effective.