Zhang Huaguang, Ming Zhongyang, Yan Yuqing, Wang Wei
IEEE Trans Neural Netw Learn Syst. 2023 Aug;34(8):4687-4701. doi: 10.1109/TNNLS.2021.3116464. Epub 2023 Aug 4.
In this article, the neural network (NN)-based adaptive dynamic programming (ADP) event-triggered control method is presented to obtain the near-optimal control policy for the model-free finite-horizon H∞ optimal tracking control problem with constrained control input. First, using available input-output data, a data-driven model is established by a recurrent NN (RNN) to reconstruct the unknown system. Then, an augmented system with event-triggered mechanism is obtained by a tracking error system and a command generator. We present a novel event-triggering condition without Zeno behavior. On this basis, the relationship between event-triggered Hamilton-Jacobi-Isaacs (HJI) equation and time-triggered HJI equation is given in Theorem 3. Since the solution of the HJI equation is time-dependent for the augmented system, the time-dependent activation functions of NNs are considered. Moreover, an extra error is incorporated to satisfy the terminal constraints of cost function. This adaptive control pattern finds, in real time, approximations of the optimal value while also ensuring the uniform ultimate boundedness of the closed-loop system. Finally, the effectiveness of the proposed near-optimal control pattern is verified by two simulation examples.
本文提出了一种基于神经网络(NN)的自适应动态规划(ADP)事件触发控制方法,以获得具有约束控制输入的无模型有限时域H∞最优跟踪控制问题的近最优控制策略。首先,利用可用的输入输出数据,通过递归神经网络(RNN)建立数据驱动模型来重构未知系统。然后,通过跟踪误差系统和指令生成器获得具有事件触发机制的增广系统。我们提出了一种无芝诺行为的新型事件触发条件。在此基础上,定理3给出了事件触发哈密顿-雅可比-Isaacs(HJI)方程与时间触发HJI方程之间的关系。由于增广系统的HJI方程的解是时间相关的,因此考虑了神经网络的时间相关激活函数。此外,引入了一个额外的误差以满足成本函数的终端约束。这种自适应控制模式实时找到最优值的近似值,同时还确保闭环系统的一致最终有界性。最后,通过两个仿真例子验证了所提出的近最优控制模式的有效性。