旋转对称型四足机器人站立-翻滚变形规划

Standing-to-rolling transformation planning for a rotational symmetric quadruped robot

设计了一种可实现翻滚的四足机器人,不仅可以采用步行方式通过崎岖地形,而且可以自主变形成为滚动体,从而采用翻滚模式通过平坦地形.机器人四肢由弓形杆件组成,机体采用球冠外形,根据旋转对称原则设计肢体的几何参数和质心分布.由站立模式向翻滚模式变形过程中,将机器人简化为平面连杆机构,建立了变形过程中机器人质心运动学模型.提出势能变化最小的变形策略,采用惩罚函数法,优化变形终止时刻机器人的位形.针对变形运动学方程的非线性特性,采用最小二乘法进行关节轨迹规划.结果表明机器人质心运动轨迹满足变形策略.

A rolling quadruped robot was proposed which not only can walk through the rugged terrain,but also can roll on the flat terrain after being automatically transformed as a rolling body.The limbs of the robot were composed of bow-shaped bars,and the shape of robot body was as spherical cap.The structure parameters and mass distribution of the robot were designed according to rotational symmetrical principle.The robot was simplified as planar linkages during the transformation from standing mode to rolling mode,and the kinematics model of the robot mass was established.The transformation strategy for the minimal potential energy variation was proposed.The penalty function method was used to search the optimal termination configuration.According to the nonlinear characteristics of the kinematics equations,the least square method was used to plan the trajectories of the joints.The result shows that the trajectory of the robot mass can meet the requirements for the proposed strategy.