3RHUR/PUS+PP混联机器人构型与性能分析

Configuration and Performance Analysis of 3RHUR/PUS+PP Hybrid Robot

为提升串并混联机器人大行程刚度与综合性能,提出一种带随动滑筒的3RHUR/PUS三自由度并联头串联XY双导轨的混联五自由度机器人构型。根据非线性约束方程组给出其位置正反解,并基于螺旋理论建立了串并混联的正逆运动学映射关系,基于建立的混联机器人的柔度模型讨论了其方向刚度;综合考虑机器人的转动能力、力传递性能、速度和刚度性能,在利用线性加权法对机器人进行多目标优化的基础上,提出最优拉丁超立方采样(Optimal Latin hypercube sampling,OptLHS)与插值相结合的优化算法,从而缩短了优化计算所需时间,得到了机器人最优尺寸参数。

In order to improve the large travel stiffness in direction Z and the comprehensive performance of the hybrid robot,a five degree-of-freedom(DOF)hybrid robot 3RHUR/PUS+PP was proposed,which was composed of a 3-DOF parallel head with a following sliding barrel in series double slideways.Firstly,the forward and inverse position solutions were given based on the nonlinear constrained equations.Considering the parallel mechanism and the series mechanism,the forward and inverse kinematics mapping relationships of the hybrid robot were established based on the screw theory,which provided the basis for the research on the overall performance of hybrid robots.The stiffness of the direction without DOF was infinity,because the hybrid robot was lower-mobility hybrid mechanism.Its direction stiffness was discussed by the flexibility model of the hybrid robot.Secondly,taking into account the rotational ability,force transmission performance,speed performance and stiffness performance of the 3RHUR/PUS+PP hybrid robot,the hybrid robot was optimized with multiple objectives on the basis of the linear weighted method.The optimization algorithm combining optimal Latin hypercube sampling(OptLHS)and interpolation was proposed,which shortened the time required to optimize the calculation and obtainedthe optimal parameters of the robot.Finally,according to the optimization result,the preferred robot parameters were obtained,and its rotational ability,speed performance and stiffness performance were studied.