Although there are fruitful results on adaptive control of constrained parametric/nonparametric strict-feedback nonlinear systems, most of them are contingent upon “feasibility conditions”, and/or are only applicable to constant and symmetric constraints. In this work, we present a robust adaptive control solution free from “feasibility conditions” and capable of accommodating much more general dynamic constraints. In our design, instead of employing the commonly used piecewise Barrier Lyapunov Function (BLF), we build a unified barrier function upon the constrained states, with which we convert the original constrained nonlinear system into an equivalent “non-constrained” one. Then by stabilizing the “unconstrained” system, the asymmetric state constraints imposed dynamically are handled gracefully. By blending a new coordinate transformation into the backstepping design, we develop a control strategy completely obviating the “feasibility conditions” for the system. It is worth noting that the requirement on the constraints to be obeyed herein is much less restrictive as compared to those imposed in most existing methods, rendering the resultant control less demanding in design and more user-friendly in implementation. Both theoretical analysis and numerical simulation verify the effectiveness and benefits of the proposed method.

尽管在约束参数/非参数严格反馈非线性系统的自适应控制方面取得了丰硕的成果，但它们大多取决于“可行性条件”，和/或仅适用于恒定和对称约束。在这项工作中，我们提出了一种健壮的自适应控制解决方案，该解决方案没有“可行性条件”，并且能够适应更一般的动态约束。在我们的设计中，我们没有采用常用的分段屏障Lyapunov函数（BLF），而是在受约束状态上构建了统一的势垒函数，利用该函数将原始受约束非线性系统转换为等效的“非受约束”系统。然后，通过稳定“不受约束”的系统，可以很好地处理动态施加的非对称状态约束。通过将新的坐标转换混入backstepping设计中，我们开发出一种控制策略，完全消除了系统的“可行性条件”。值得注意的是，与大多数现有方法所施加的约束相比，此处要遵守的约束要求的约束性要小得多，从而使得所得控件在设计上的要求降低，实现起来更加用户友好。理论分析和数值模拟都验证了该方法的有效性和优势。使得最终的控件在设计上的要求降低，并且在实现上更加用户友好。理论分析和数值模拟都验证了该方法的有效性和优势。使得最终的控件在设计上的要求降低，并且在实现上更加用户友好。理论分析和数值模拟都验证了该方法的有效性和优势。