非奇异快速终端滑模控制

现有的非奇异终端滑模控制方法和非奇异快速终端滑模控制方法都存在收敛速度缓慢以及“收敛停滞”等问题,针对这些问题提出了一种改进方法。在保证控制器非奇异的条件下将原滑模面中指数项设计参数由分数扩展到正实数域,既提高了收敛速度又扩大了参数选择的灵活性;引入快速终端趋近律,将原来的线性或指数渐近趋近改进为快速终端趋近,提高了系统状态的趋近速度;对“收敛停滞”问题产生的原因进行分析,提出了设计参数所应满足的条件。最后对某无人平台进行航向跟踪数值仿真,仿真结果验证了改进方法的有效性。

Study on nonsingular fast terminal sliding mode control

The existing nonsingular terminal sliding mode control (NTSMC) and nonsingular fast terminal sliding mode control share the same drawbacks of slow convergence speed and the convergence stagnation, and aiming at these problems, an improved method is proposed. Without losing nonsingularity, the index of the exponential terms of sliding surface is expanded from fraction to real, which increases the convergence speed and flexibility at the same time. By applying the fast terminal approaching law, the approaching movement is changed from linear or exponential movement to fast terminal movement. The reason for the occurrence of convergence stagnation is analyzed in detail, and a law that the design parameters should satisfy is deduced theoretically. Finally, course tracking simulations conducted on an unmanned platform validate the effectiveness of the improved method.