为了提高四足机器人的运动灵活性和复杂环境适应性，设计了一种 Ｒ + {2-UPＲ + ＲPＲ}腿机构，并利用螺旋理论分析得知该机构具有两转动和一移动 3 个自由度; 接着， 根据空间中构件和运动副的位置关系，推导出运动学反解和正解方程，求解驱动构件速 度、加速度; 然后，借助 Matlab 计算软件和 ADAMS 仿真软件，通过对比运动学正反解 的理论计算结果与仿真结果来验证正反解模型的准确性; 最后，通过对机器人单腿的运 动仿真，得到腿部机构的运动轨迹和速度变化情况，并对腿部机构的工作空间进行分 析，得到其足端的可达工作范围及运动特点。结果表明，该腿部机构具有较好的工作适 应性和运动灵活性，关节数少且较独立。

An Ｒ + { 2-UPＲ + ＲPＲ} leg mechanism was designed to improve the mobility and adaptability of quadruped robots in complex environment． The spiral theory analysis showed that the mechanism has 3 freedom degrees of two rotations and one movement． Then，the inverse kinematics solution and the positive solution equation were derived based on the position relationship between the member and the motion pair in space，and the velocity and acceleration of the driving member were solved． Then，with the help of Matlab calculation software and ADAMS simulation software，the accuracy of the positive and negative solution model was verified through the comparison of kinematics positive and negative solution theoretical calculation results and simulation results． Finally，the motion trajectory and velocity changes of the leg mechanism were obtained through the motion simulation of the robot's single leg． And the working space of the leg mechanism was analyzed to obtain the working range and motion characteristics of the foot end． The results show that the proposed leg mechanism with less independent joints has better working adaptability and movement flexibility．