3—CRPa移动并联机构运动学分析与仿真

提出一种新型3自由度纯移动并联机构,该机构由动平台、静平台以及联接两平台的3条相同的分支运动链组成。基于单开链单元理论分析,计算出机构的自由度,分别讨论了以角位移和线性位移为主动输入形式的机构运动学问题,推导出位置、速度、加速度的解析解。利用Matlab和Pro/E软件分别绘制出机构的位移、速度、加速度理论曲线和虚拟样机仿真曲线,仿真结果证明了理论分析的正确性。尤其是当以线性输入为主动输入时,机构的运动雅可比矩阵为单位阵且条件数恒等于1,所以此时机构在整个工作空间内表现为完全各向同性。

Kinematic Analysis and Simulation of 3-CRPa Translational Parallel Mechanism

A novel translational parallel mechanism with three degrees of freedom was presented,which consisted of a moving platform connecting with a fixed base by three identical limbs.Mobility of the moving platform was analyzed and calculated according to the units of single-open-chain.Kinematic problems were discussed by means of different actuated joints inputs,i.e.,rotational angle displacements and linear displacements,respectively.The analytical solutions of position,velocity and acceleration were derived.The kinematic simulation of this mechanism was carried out by Matlab and Pro/E software.Position,velocity and acceleration curves were described based on the analytical solutions and virtual prototype.Simulation results showed that the theoretic analysis was correct and feasible.When the linear displacements are selected as the actuated inputs,the Jacobian matrix of the mechanism is an identity one and its condition number is always equal to 1.The parallel mechanism,therefore,is full-isotropic throughout the entire workspace in this case.