平行导轨二滑块驱动在一侧的并联操作手的运动轨迹实现与仿真研究

Realization and Simulation of Motion Trajectory of a 2-DOF Parallel Manipulator Driven by Two Sliders Moving on the Parallel Guides

以平行导轨二滑块驱动在一侧且内点作为操作点的并联机构为研究对象,在给出显式位移、速度、加速度运动学逆解模型的基础上,对其运动轨迹进行了分析仿真研究;在操作头轨迹规划中,加减速及匀速阶段采用四次多项式进行拟合,拐角段采用对称的Clothoid曲线光滑匀速过渡;同时,利用运动学逆解确定了操作点按预期轨迹运动时应在原动件上施加的运动规律;最后,利用虚拟样机技术对所规划的运动轨迹进行仿真验证。仿真结果表明:并联机构驱动滑块的速度、加速度及作用在滑块上的驱动力均为连续函数,机构运行平稳,操作点的位置和速度与规划一致,能够满足操作点快速和实时控制的要求。

A kind of 2-DOF parallel manipulator driven by two sliders moving along two parallel guides is analyzed.Based on the explicit expression of inverse position,velocity and acceleration analyses,the mobile trajectory of this manipulator is investigated and simulated.In trajectory planning,the trajectory profiles are assigned to be accelerated and decelerated at the first and last few seconds,respectively,and keep at constant speed for the remainder of time,where the forth-order polynomial is fitted during acceleration and deceleration,and clothoid curve is applied around the corner of axis.Then the mobile rule exerted on the actuator sliders is obtained using inverse position based on the desired end-effecter trajectory.Finally,the virtual prototype of this mechanism is modeled using Solidwork and the kinematics and dynamics simulation is performed using Cosmostion.The result shows that both velocity,acceleration of the sliders and the driving force exerted on the sliders are continuous curves,which can fully satisfy the demand of high-accuracy and real-time processing of the high-speed manipulator.