基于能量反馈与OGY法的机器人混沌步态控制

Chaotic robot gait control based on energy feedback and OGY method

针对双足机器人被动步行中的混沌步态,提出一种基于自适应能量反馈与OGY法的混合控制方法,将混沌步态快速转换到单周期稳定步态。首先,利用Poincaré截面,将双足机器人混合动力学系统离散化,求取该系统的不动点;然后,将机器人自身不动点处的机械能作为参考能量,在保证系统渐进稳定的前提下,构造自适应能量反馈控制律,使机器人状态迅速收敛至自身不动点小的邻域内;进一步地,利用OGY法对机器人支撑腿处的变量施加微扰,把机器人混沌状态稳定在自身的不动点上,实现了对混沌步态的快速控制。仿真实验和机器人行走实验结果表明了所提控制方法的有效性。

Aiming at the chaotic gait of the biped robot in passive dynamic walking, a hybrid control method based on adaptive energy feedback and OGY method is proposed, which makes the chaotic gait converted to the single-cycle stable gait rapidly. Firstly, the Poincaré section is utilized to discretize the hybrid dynamics system of the biped robot, and the fixed point of the system is obtained. Then, taking the mechanical energy at the fixed point of the biped robot as the reference energy, the adaptive energy feedback control law is constructed on the premise of ensuring the system asymptotical stabilizing, which makes the state of the biped robot converged rapidly to a little neighborhood of its fixed point. Furthermore, the OGY method is used to exert perturbation to the variables of the supporting leg of the robot, the chaotic state of the robot is stabilized at its fixed point, and the fast control of the chaotic gait is achieved. The results of simulation and robot walking experiment show the effectiveness of the proposed control method.