Adaptive Neural Control of Hypersonic Vehicles with Actuator Constraints

Abstract

An adaptive neural control method is proposed in this paper for the flexible air-breathing hypersonic vehicle (AHV) with constraints on actuators. This scheme firstly converts the original control problem with input constraints into a new control problem without input constraints based on the control input saturation function. Secondly, on the basis of the implicit function theorem, the radial basis function neural network (RBFNN) is introduced to approximate the uncertain items of the model. And the minimal-learning-parameter (MLP) technique is adopted to design the adaptive law for the norm of network weight vector, which significantly reduces calculations. Meanwhile, the finite-time convergence differentiator (FD) is introduced, through which the model state variables and their derivatives are accurately estimated to ensure the control effect. Finally, it is theoretically proved that the closed-loop control system is stable. And the effectiveness of the designed controller is verified by simulation.

Adaptive Neural Control for Nonaffine Pure‐Feedback System Based on Extreme Learning Machine

“…The MLP algorithm is adopted to adaptively adjust the norm of the weight vector, which greatly reduces the amount of adaptive calculations. And through employing FD to achieve effective estimation of the system state variables, the control accuracy is ensured [24]. Simulation examples verify the effectiveness and the superiority of the design method.…”

“…At this point, using ELM to approximate Ψ( , ), only is needed as the input signal of the neural network to obtain a satisfactory approximation effect. This is where the special meaning of the implicit function theorem lies [24].…”

“…where , where 0 represents nominal value and stands for simulation value. And after 50s, add external disturbances 1 = 2 sin(0.1 ) and 2 = 0.02 sin(0.1 ) to (64) and (68) in AHV model, respectively [24]. The subscript "1" in the Figures 3 to 11 shows the result obtained by the proposed method and the subscript "2" shows the result obtained by the method of [19].…”

Guardian Map Approach to Feasible Range of Static Stability Margin of Hypersonic Flight Vehicles with Input Saturation

“…Plenty of advanced control methods have been investigated to address the flight control problems [5,6]. The majority focuses on the adaptive nonlinear approach for non-affine models with mismatched disturbance [7,8] and large-envelope tracking problem with global stability and prescribed performance [9][10][11]. The global stability can be hardly guaranteed in closed-loop system with input saturation since the longitudinal dynamics is inherently unstable for hypersonic flight [12].…”

Fuzzy-Approximation-Based Novel Back-Stepping Control of Flexible Air-Breathing Hypersonic Vehicles with Nonaffine Models

“…International Journal of Aerospace Engineering loop system simulation of FHV is carried out by using the method presented in this paper (controller 1) and the method of adaptive neural control with nonaffine dynamics (controller 2) in [34]. When the actuators are constrained, the simulation results using the two methods are shown in Figures 8-14.…”