Saturated Control Design For Feedforward Nonlinear Systems Subj Ect To Input Delay

Sensor delay or transport delay often appears in the input, also, actuator saturation is commonly encountered in control engineering. The saturated delayed feedback, or the saturated design for the systems subject to an arbitrarily large input delay, has thus attracted much attention. Based on equivalent transformations and robust stability theories to robustly stabilize a null-controllable linear system, one only needs to focus on a feedforward linear system that consists of multiple integrators and multiple oscillators. In view of this observation, this article addresses the saturated delayed design of the feedforward nonlinear systems whose nominal dynamic contains multiple integrators and multiple oscillators.The main works of this paper are stated as follows:First, the saturated design for the null-controllable linear systems is conducted. After decomposition, we only need to deal with the single-input null-controllable linear system whose nominal dynamics contains both multiple integrators and multiple oscillators, and present a class of simple saturated control laws. We do not follow the existing method which depends on passivity theory, but fully use a suitable normal form and elaborately assign saturated control laws. As a result, an iteration analysis mechanism is established and has been naturally extended to the case of high-order feedforward nonlinear systems.Second, we address the saturated delayed designs of the multiple integrators subject to nonlinearities. Based on a special coordinate transformation, the concerned system is transformend into the one which does not contain an input delay, and the saturated delayed design problem reduces to the pure saturated design issue. In this way, the ananlysis compexity is relaxed and the establishe algorithm is able to compensate an arbitrarily large input delay by tuning a related parameter.Third, considering the affect of actuator saturation, input delay, and nonlinear terms, we design saturated delayed control laws for the feedforward nonlinear system whose nominal dynamics is the cascade of multiple oscillators and multiple integrators. Here we have mainly solved the problem that the existing algorithms of compensating an arbitrarily large input delay are hard to be directly applied to the multiple oscillators.At last, as applications, explicit saturated delayed control laws have been presented for the null-controllable nonlinear systems and the translational oscillation rotational actuation (TORA) model.