Dynamic Surface Control Using Neural Networks for a Class of Uncertain Nonlinear Systems With Input Saturation

In this article, a backstepping control scheme is developed for the motion control of a Three degrees of freedom (3DOF) model helicopter with unknown external disturbance, modelling uncertainties and input and output constraints. In the developed robust control scheme, augmented state observers are applied to estimate the unknown states, unknown external disturbance and modelling uncertainties. Auxiliary systems are designed to deal with input saturation. A barrier Lyapunov function is employed to handle the output saturation. The stability of closed-loop system is proved by the Lyapunov method. Simulation results show that the designed control scheme is effective at dealing with the motion control of a 3DOF model helicopter in the presence of unknown external disturbance and modelling uncertainties, and input and output saturation.

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“…41 Based on Assumption 1, it is obvious that the time derivation of equivalent disturbance _ " D is bounded. We can obtain that…”

Section: Remarkmentioning

confidence: 99%

Backstepping control for a 3DOF model helicopter with input and output constraints

Mei

Cui

2016

International Journal of Advanced Robotic Systems

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“…Input saturation has an effect on control performance, which has been investigated in the last few decades. [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] The Takagi-Sugeno fuzzy modeling approach was utilized to control the nonlinear systems with actuator saturation in the work of Cao and Lin. 37 The stabilization problem was addressed for a class of Hamiltonian systems with state time-delay and input saturation in the work of Sun.…”

Section: Introductionmentioning

confidence: 99%

Robust adaptive constrained boundary control for a suspension cable system of a helicopter

Ren

Shi

2017

Adaptive Control & Signal

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SummaryIn this article, the problems of modeling and controlling are investigated for a suspension cable system of a helicopter with input saturation, system parameter uncertainties, and external disturbances by using the boundary control method.In accordance with the Hamilton's principle, the model of the suspension cable system of a helicopter is established by using a set of partial differential and ordinary differential equations. Considering nonsymmetric saturation constraint, the auxiliary systems are designed to handle with the effect of input saturation. Considering Lyapunov's direct method and the designed auxiliary systems, two robust adaptive boundary controllers are provided by the actuators at the helicopter and the box. Under the proposed controllers, the error between the bottom payload and the target location and the vibration range are uniformly ultimately bounded. Moreover, they will converge to a small neighborhood of zero by selecting the suitable parameters. Meanwhile, to guarantee the validity of the proposed adaptive boundary control laws, some sufficient conditions are raised. Simulation results are provided to verify that the effectiveness of the designed controllers in this paper.

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“…11 In order to overcome this demerit, dynamic surface control was employed to facilitate the controller design by letting the virtual command pass through a first-order filter. [11][12][13][14] In order to further eliminate the complexity of the immediate controllers in the recursive design, a hyperbolicsine-function-based tracking differentiator was constructed to obtain good estimations for the derivatives of virtual controllers involved in the control system design of an air-breathing hypersonic vehicle (AHV) in the work by Bu et al 15 However, some issues are still open for differentiators such as a good dynamic response and high estimation accuracy.…”

Section: Introductionmentioning

confidence: 99%

Efficient adaptive constrained control with time-varying predefined performance for a hypersonic flight vehicle

Wei

Luo

Dai

et al. 2017

International Journal of Advanced Robotic Systems

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A novel low-complexity adaptive control method, capable of guaranteeing the transient and steady-state tracking performance in the presence of unknown nonlinearities and actuator saturation, is investigated for the longitudinal dynamics of a generic hypersonic flight vehicle. In order to attenuate the negative effects of classical predefined performance function for unknown initial tracking errors, a modified predefined performance function with time-varying design parameters is presented. Under the newly developed predefined performance function, two novel adaptive controllers with low-complexity computation are proposed for velocity and altitude subsystems of the hypersonic flight vehicle, respectively. Wherein, different from neural network-based approximation, a least square support vector machine with only two design parameters is utilized to approximate the unknown hypersonic dynamics. And the relevant ideal weights are obtained by solving a linear system without resorting to specialized optimization algorithms. Based on the approximation by least square support vector machine, only two adaptive scalars are required to be updated online in the parameter projection method. Besides, a new finite-time-convergent differentiator, with a quite simple structure, is proposed to estimate the unknown generated state variables in the newly established normal output-feedback formulation of altitude subsystem. Moreover, it is also employed to obtain accurate estimations for the derivatives of virtual controllers in a recursive design. This avoids the inherent drawback of backstepping -"explosion of terms" and makes the proposed control method achievable for the hypersonic flight vehicle. Further, the compensation design is employed when the saturations of the actuator occur. Finally, the numerical simulations validate the efficiency of the proposed finitetime-convergent differentiator and control method.

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Dynamic Surface Control Using Neural Networks for a Class of Uncertain Nonlinear Systems With Input Saturation

Cited by 421 publications

References 54 publications

Backstepping control for a 3DOF model helicopter with input and output constraints

Backstepping control for a 3DOF model helicopter with input and output constraints

Robust adaptive constrained boundary control for a suspension cable system of a helicopter

Efficient adaptive constrained control with time-varying predefined performance for a hypersonic flight vehicle

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