Kinematics and dynamics analysis of a 3-7R parallel decoupling mechanism

One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three orthogonal distributional branch-chains, and all movable pairs are rotational joints. The movable platform of the mechanism has x, y, z translational decoupling directions. Furthermore, in order to verify the mechanism＇s decoupling characteristics, the mechanism＇s kinematics analysis is solved, and the mechanism＇s direct/inverse kinematics model, input/output velocities and accelerations are deduced, which confirm its decoupling movement characteristics. Finally, one kind of mechanism link decomposed-integrated approach is adopted, and the mechanism＇s dynamics model is completed with the Lagrange method, which also proves its decoupling force characteristics. All of these works provide significant theory for the further study of the mechanism＇s control strategy, design, path planning etc.

重力对超静定结构受力的影响

目前有关超静定结构的受力分析中几乎均未考虑分支重力的影响,针对此,提出了一种考虑分支重力情况下超静定结构受力分析的方法。首先基于分支的力矩平衡方程直接求解出在分支重力作用下产生的施加给动平台的垂直分支轴线方向的约束力分量,并将其视作施加给结构的广义外力;然后基于结构变形协调关系和受力平衡方程,获得超静定结构各分支沿其轴线方向的约束力分量的完整解析表达式以及存在制造误差时装配内力的解析表达式;最后讨论了分支重力对超静定结构受力的影响机理。以平面超静定结构3-RR和空间超静定结构7-SS为例进行了实例分析,并建立对应的刚柔混合模型,进行了仿真验证。

基于MATLAB的串并混联7-DOF仿人机械臂正运动学分析及仿真

设计了一种串并混联7-DOF仿人机械臂,并通过对并联机构进行运动学分析和D-H建模,建立了仿人机械臂正运动学的数学模型;运用MATLAB中的Robotics工具箱对仿人机械臂进行正运动学仿真,得到连续平滑的关节角度规划曲线和腕部笛卡尔空间轨迹。仿真结果表明,设计的仿人机械臂结构参数合理,为仿人机械臂的优化设计提供了依据。