在采用线性耦合振荡器模型的仿人机器人步态规划中,振荡器部分参数依靠手动调整难以获得能稳定行走的值,故提出了一种优化振荡器参数的算法以改善整个步态规划方法.将机器人的步行速度、行走过程中的质心振动幅度和ZMP(zero moment point)曲线的回绕率组合起来作为优化目标,定义并选定ZMP稳定裕度为约束条件,采用带约束的非线性优化方法作为求解工具,在部分参数固定的情况下,计算得到线性耦合振荡器部分参数的最优值.仿真结果表明,优化方法选择的参数能在保证较大ZMP稳定裕度的情况下实现机器人的快速步行.在DARwIn-OP仿人机器人开放平台上进行的步态规划实验结果表明,优化得到的线性耦合振荡器参数能保证仿人机器人以较大速度稳定行走。
For the gait pattern planning algorithm of humanoid robots with the linear coupled oscillator model, some oscillator parameters were chosen by manual adjustment, which makes it difficult to get the parameters' values that could ensure stable walking. To reduce the time of parameter selection and simplify the gait planning algorithm, a parameter selection algorithm based on linear coupled model for humanoid robots was proposed. By combining the walking speed, oscillation amplitude of the mass center during walking, and the trajectory curvature of ZMP, the optimization goal was established. The stable margin was defined and chosen as a constraint condition, and the nonlinear constraint method was used to obtain the optimization parameters which could ensure stable walking at faster speed. Simulation experiment demonstrated that the optimization parameters could ensure stable walking with rich stable margin. The proposed method wasimplemented on the open humanoid platform DARwin OP, and the results indicate that the optimized parameters in the linear coupled oscillator can achieve stable walking with fast gait pattern generation.