This paper designs an adaptive robust controller for a class of strict-feedback nonlinear systems with time- varying parameters and bounded control coefficient and disturbances. Incorporating Nussbaum function gain and smooth projection algorithm with adaptive backstepping design tools, this design method does not require a priori knowledge of the sign of the time-varying control coefficient and the bound of time-varying parameters and disturbances. By means of Lyapunov function and related lemmas, we prove that the designed adaptive robust nonlinear controller guarantees the global uniform boundedness of all signals of the resulting closed-loop system. The desired system performances can be achieved by appropriately selecting the design parameters. Simulation studies show the feasibility and effectiveness of the presented approach.%针对一类带有有界控制系数和有界扰动的时变参数严反馈非线性系统，将Nussbaum函数增益及光滑投影算法与自适应逆推设计工具相结合，提出一种自适应鲁棒非线性控制方案．在此方案中无需知道控制系数的符号，以及时变参数和扰动的界．借助Lyapunov数及相关引理证明了所设计的自适应鲁棒非线性控制器能保证闭环系统中的所有信号全局一致有界．可以通过恰当地选取设计参数，保证系统具有任意指定的控制性能．仿真研究证明了所提出算法的可行性和有效性．
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