变刚度柔性机器人关节的设计与解耦控制方法

Design and decoupling control of variable-stiffness flexible robot joint

设计一种采用永磁变刚度装置的绳索驱动式柔性机器人关节,在不增加驱动力的情况下,增加关节刚度调整范围。详细阐述关节的机械结构和变刚度原理。利用雅可比矩阵和模型间静力学关系,得到关节刚度,位置和绳索伸长量的对应关系,实现了刚度与位置解耦。建立变刚度关节的动力学模型,以轨迹控制为目标,设计解耦控制器,搭建实验系统,验证本方案的可行性。采用永磁弹簧,绳索驱动的柔性关节可以有效的减小关节的质量,惯性和体积,同时具有较大的刚度调整范围以及较短的调整时间,较快的响应速度和较小超调量。此柔性关节的构型和控制方式也适用于多自由度柔性并联机器人关节的构建。

The wire-driven flexible robot joint using permanent magnetic variable-stiffness mechanism was designed,which increases the variable-stiffness range,without increasing the driving tension.The principle and structure of the variable-stiffness flexible robot joint were explained.The correspondence between joint stiffness,joint position and wire length were obtained by using the Jacobi matrix and the mechanics relationship between models,which realizes the decoupling of stiffness and position.The dynamic model of the variable-stiffness joint was established,a decoupling controller was designed,based on the trajectory control,and the experimental system was set up to verify the feasibility of the scheme.Using permanent magnet spring and wire-driven,the flexible joint can effectively reduce the weight,inertia and volume of the joint,and at the same time,it has a greater variable-stiffness range,a shorter stiffness adjustment time,a faster response and a smaller overshoot.This configuration and control method are also suitable for multi-degree parallel flexible joints.