In this paper, the stabilization problem of nonlinear time-delay systems in presence of known exogenous disturbances and by means of quantized sampled-data event-based controllers is investigated. In particular, nonlinear systems with state delays are studied. Known exogenous disturbances affecting the plant dynamics are considered in order to address, for instance, tracking control problems commonly studied by considering the stabilization problem of the corresponding tracking error system in which the chosen reference signal appears as a known exogenous signal. The stabilization in the sample-and-hold sense theory is used as a tool to provide sufficient conditions for the existence of a suitably fast sampling and of an accurate quantization of the input/output channels such that: the quantized sampled-data implementation of continuous-time controllers, updated through a proposed event-based mechanism, guarantees the semi-global practical stability property, with arbitrarily small final target ball of the origin, of the related closed-loop system. A spline approximation methodology is used in order to: (i) cope with the problem of the possible non-availability in the buffer of suitable past values of the system variables needed for the digital implementation of the controller; (ii) consider approximations related to the hardware implementation of the signal describing the known exogenous disturbance (e.g., the chosen reference signal). The provided results include the case of non-uniform quantization of the input/output channels and the case of aperiodic sampling. Applications are presented in order to validate the results, one of which concerning a single-link flexible joint robot arm with time delays.

中文翻译：

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具有外生干扰的非线性时滞系统的基于数字事件的控制

在本文中，研究了存在已知外源干扰并通过量化采样数据基于事件的控制器的非线性时滞系统的稳定性问题。特别是，研究具有状态延迟的非线性系统。考虑影响被控对象动态的已知外源扰动，以便解决例如通常通过考虑相应跟踪误差系统的稳定问题来研究的跟踪控制问题，其中所选择的参考信号表现为已知的外源信号。采样保持传感理论中的稳定性被用作一种工具，为输入/输出通道的适当快速采样和精确量化的存在提供充分的条件，使得：连续采样的量化采样数据实现-时间控制器，通过所提出的基于事件的机制进行更新，保证了相关闭环系统的半全局实际稳定性属性，其中原点的最终目标球是任意小的。使用样条近似方法是为了：(i)处理控制器的数字实现所需的系统变量的合适的过去值在缓冲器中可能不可用的问题； (ii)考虑与描述已知外源干扰的信号的硬件实现相关的近似（例如，所选择的参考信号）。提供的结果包括输入/​​输出通道的非均匀量化的情况和非周期采样的情况。为了验证结果，提出了应用程序，其中之一涉及具有时间延迟的单连杆柔性关节机器人臂。