齿轮-五杆组合机构运动学特征仿真分析

Gear-5-bar combination mechanism's kinematics characteristic simulation

机械手常采用齿轮-五杆组合机构完成物料抓取动作,它由定轴轮系匀速旋转,向两自由度五杆机构传递运动。由于II级杆组轨迹通过第I级两个齿轮转角合成为位移输出,致使外伸点位移计算过程相对复杂,基于零件坐标变换求解的通用办法给出齿轮-杆组合机构的运动学推导结果,但编写程序完成仿真及后处理过程仍相对困难。为直观表达机构运动学规律,由ADAMS软件建立参数化模型,通过改变杆件长度、传动比和连架杆起始角相位差,寻求连架杆输出轨迹的改变规律。仿真结果表明齿轮对两曲柄的运动关联输出导致增大连架杆初始相位角时,外伸杆端点轨迹在横、纵两方向上均增大。

In order to accomplish a mission of grab materials, gear-link complex combination mechanism often used on the design of manipulator arm, which pass a motion to a two-degree-of-freedom five-bar mechanism by fixed axis gear system in uniform angular velocity. Due to level-II link＇ s trajectory output control by two level-I gears＇ turn angles,endpoint＇ s displacement is relatively hard to compute. Though some documents had gave a way to deduce a kinematic result of gear-5-bar combination mechanism, sim- ulation and post-process still can be a real problem by programming. For the aim of deducing the inner relation of this mechanism＇ s pose characteristics, a parameter model will be built by using ADAMS. By change some factors such as length,the links＇ phase difference of starting angular and the transmission ratio of gears, find the rules about output orbit of link. Because of related motion output between gear and links, the simulation result shows when increasing the starting angular of links, the links＇ endpoint traj ectory in horizontal, vertical directions are also increased.