Theoretic and Experimental Research on The Nonlinear Control of Nonlinearly Actuated Systems and The Steering of Mobile Robots

本研究旨在为非线性驱动系统和移动机器人的转向开发实用的非线性控制方法。并开发了相应的控制系统包。得到的结果如下：1。针对链式系统这一类移动机器人，提出了一种切换控制算法。该方法保证了全局指数收敛性，并具有明显的特点，可以应用于具有空间约束和转向角度限制等物理约束的移动机器人转向控制。在此基础上开发了一个现实的自动泊车系统，该系统能够处理受车库约束和转向角度限制的泊车任务。大量的实验验证了该方法的高适用性。此外，为了更有效地完成停车任务，通过引入辅助停车目的地，建立了各种停车算法。作为自动停车控制的另一种选择，基于自行车家族跟踪的思想提出了另一种方法。实验结果也证实了该方法的有效性。针对典型的非线性驱动系统电磁轴承系统，建立了一种低偏置非线性动态输出反馈控制方法。通过使用这种方法，偏置电流大大减小。并且，将这种动态输出反馈控制方法推广到具有时变转速和柔性的被控对象。作为一个对偶问题，对线性作动器驱动的非线性系统的控制也进行了研究。为了保证整个系统的稳定性，对直线执行器的速度应该有多快进行了定量分析。我们还成功地实现了独轮车机器人的运动控制和旋转起重机的高速非线性控制。此外，在H2控制器的模型约简、电机驱动系统的自适应控制以及H_∞控制解的新推导等方面获得了新的知识。从而达到了本研究的目的。少

This research aims at developing practical nonlinear control methods for nonlinearly actuated systems and the steering of mobile robots. The corresponding control system packages are also developed. The obtained results are listed below :1.A switching control algorithm has been proposed for chained systems, a general class of mobile robots. This method guarantees the global exponential convergence and has a distinctive feature that it can be applied to the steering control of mobile robots with physical constraints such as space constraint and steering angle limitation.2.A realistic automatic parking system has been developed based on the above algorithm, which is able to handle parking tasks subject to garage constraint and steering angle limitation. Its high applicability has been validated by numerous experiments. Further, in order to achieve parking task more efficiently various parking algorithms have been established via the introduction of auxiliary parking destinations.3.As an … More alternate for automatic parking control, another method has been proposed based on the idea of tracking of a cycle family. Its effectiveness has also been verified by experiments.4.A nonlinear dynamic output feedback control method using low bias has been established for electromagnetic bearing systems, a typical nonlinearly actuated system. By the use of this method, the bias current is reduced dramatically.5.Moreover, this dynamic output feedback control method is extended to handle plants with time-varying rotation speed and flexibility.6.As a dual problem, the control of nonlinear systems driven by linear actuators has also been studied. A quantitative analysis has been conducted to answer the question that how fast should the linear actuator be in order to ensure the stability of the whole system.We have also succeeded in the motion control of a unicycle robot and the high speed nonlinear control of a rotary crane. Further, new knowledge have been obtained on the model reduction of H2 controllers, adaptive control of motor-driven systems and new derivation of H_∞ control solution. As a result, the objective of this research has been achieved. Less