针对轮式移动机器人在曲面上运动时的镇定问题,结合横截函数方法和积分器backstepping技术,设计了实现机器人在曲面上实际镇定的光滑控制律.首先构造横截函数,由该横截函数定义出嵌入子流形;充分利用轮式移动机器人运动学模型对标准SE(2)群运算的左不变性,对相应的误差系统设计出光滑指数镇定控制律,实现运动学子系统的实际镇定;用积分器backstepping方法对轮式移动机器人的简化动力学模型推导出实际镇定控制律.整个设计过程系统化,相比于通常的光滑镇定律,所设计的控制律显著提高了闭环系统的收敛速度.仿真结果验证了算法的有效性.
The stabilization problem of nonholonomic wheeled mobile robots that move on uneven surface is investigated. Smooth control laws ensuring practical stabilization are proposed based on the transverse function approach and the integrator backstepping idea. Firstly, a transverse function is constructed, which defined a smooth embedded submanifold; based on the left-invariance property of the kinematic model of the wheeled mobile robots with respect to the standard group operation of SE (2), smooth exponential stabilizing control laws are proposed for the corresponding error system; then integrator backstepping technique is utilized to derive the practical stabilizing control laws for the dynamic system. The whole design process is systematic. Compared to some general smooth stabilizing laws, the proposed control law speeds up the convergence of the closed-loop system. Simulations are provided to demonstrate the effectiveness of the algorithm.