四足机器人对角小跑步态非线性控制方法仿真

Simulation of Nonlinear Control Method for Diagonal Running State of Four-legged Robot

针对现有的四足机器人对角小跑步态控制方法存在的机器人运动速度较慢、灵活性较差等问题,提出了一种基于虚拟模型的四足机器人对角小跑步态非线性控制方法。方法需要构建一个四足机器人模型,并在该模型的工作范围内建立一个平面直角坐标系,在不考虑机器人足端车轮滑动的情况下,将驱动四足机器人的运动方程转换成矩阵的形式,寻找有界输入平动线速度和转动角速度,使矩阵在其控制下产生的误差可以在大范围内保持稳定。求解该四足机器人在工作平面坐标系中姿态误差的微分方程,构造该微分方程的Lyapunov函数并对其求导,根据求导结果设计一个四足机器人驱动控制器,通过该驱动控制器实现对四足机器人的对角小跑步态非线性控制。仿真结果表明,所提方法能够在快速、灵活的情况下实现对四足机器人对角小跑步态的非线性控制,且鲁棒性较高,能够满足用户需求。

This article puts forward a method of non-linear control for trotting gait of quadruped robot based on virtual model.It is necessary to construct a quadruped robot model and establish a plane rectangular coordinate sys-tem within the working range of this model.Without considering the wheel sliding at the foot end of robot,the motion equation of quadruped robot was transformed into the form of matrix.Moreover,the mean linear velocity of bounded input and rotational angular velocity were searched,so that the error produced by the matrix under its control could be stable for a wide range.The differential equation of attitude error of the quadruped robot in the working plane coordi-nate system was solved.Lyapunov function of the differential equation was constructed to find its derivative.Accord-ing to the derivative result,a quadruped robot driving controller was designed.Through this driving controller,the trotting gait of this quadruped robot could be controlled nonlinearly.Simulation results verify that the proposed method can realize the non-linear control for the trotting gait of quadruped robot in fast and flexible cases.Meanwhile,this method has high robustness,and it can satisfy the needs of users.