Fuyang Chen

Robust Backstepping Sliding-Mode Control and Observer-Based Fault Estimation for a Quadrotor UAV

This study gives the mathematic model of a quadrotor unmanned aerial vehicle (UAV) and then proposes a robust nonlinear controller which combines the sliding-mode control technique and the backstepping control technique. To achieve Cartesian position trajectory tracking capability, the construction of the controller can be divided into two stages: a regular SMC controller for attitude subsystem (inner loop) is first developed to guarantee fast convergence rapidity of Euler angles and the backstepping technique is applied to the position loop until desired attitudes are obtained and then the ultimate control laws. The stability of the closed-loop system is guaranteed by stabilizing each of the subsystems step by step and the robustness of the controller against model uncertainty and external disturbances is investigated. In addition, an adaptive observer-based fault estimation scheme is also considered for taking off mode. Simulations are conducted to demonstrate the effectiveness of the designed robust nonlinear controller and the fault estimation scheme.

Adaptive compensation control of the quadrotor helicopter using quantum information technology and disturbance observer

Abstract In this paper, an adaptive compensation control scheme is developed via disturbance observer and quantum information technology for the four-rotor helicopter, which can handle the control problems of helicopters attitude with the unknown actuator failures and external disturbance effectively. Both the digital simulations and the semi-physical simulations in a Quanser 3-DOF hover platform illustrate the effectiveness of the proposed compensation control scheme.

A Reconfiguration Scheme for Quadrotor Helicopter via Simple Adaptive Control and Quantum Logic

A reconfiguration control scheme is proposed for a quadrotor helicopter with loss of control effectiveness via simple adaptive control and quantum logic. Some good control performances of the helicopter can be achieved by applying quadratic optimal control with scheduled stability degree when the system is in normal operation. A parallel feedforward compensator is introduced to fulfill the condition of positive realness, and thus, the simple adaptive controller can be utilized for the helicopter. Quantum logic is also applied to the quadrotor control system, which achieves the quantization of the disturbances patterns. A mathematical model of the quadrotor helicopter for application is obtained from its dynamic equations with pitch, roll, and yaw axes, which includes the parameter perturbation and outer disturbances. Several simulation and experimental results for the faulty helicopter validate the robustness and reconfiguration control capability of the proposed scheme.

Self-repairing control of a helicopter with input time delay via adaptive global sliding mode control and quantum logic

This study proposes a solution to the problem of designing adaptive global sliding mode controllers for a class of linear helicopter systems with actuator faults and time delay. An adaptive global sliding mode control approach is proposed based on dynamic nonlinear sliding mode function and adaptive law. The advantages of the controller include elimination of the reaching movement of traditional sliding mode control, realization of online identification of the fault value, and overcoming of the effect of the actuator faults and time delay. In addition, quantum information technique is used to increase the control accuracy of helicopter. Simulation results demonstrate the efficiency and superiority of the proposed method.

An intelligent self-repairing control for nonlinear MIMO systems via adaptive sliding mode control technology

Abstract In this paper, an intelligent self-repairing control scheme is proposed for a class of nonlinear MIMO system. A direct self-repairing controller of a nonlinear SISO system is firstly designed, and then the control scheme is promoted to a nonlinear MIMO system. The error signals are replaced by the state variables to deal with the high derivate problems of the desired signals and a nonlinear regulating function is brought in to improve the performances of the sliding mode. The self-repairing controller is made up of four parts: the nonlinear regulator, the equal controller, the compensator I and the compensator II. The control method is applied to a helicopter flight control system with loss-in-effectiveness faults. Some simulation results illustrate the effectiveness and feasibility of the proposed control scheme in the paper.

Trajectory tracking of a quadrotor with unknown parameters and its fault-tolerant control via sliding mode fault observer:

Based on the nonlinear equations of a quadrotor, position tracking with unknown parameters and fault-tolerant control scheme is proposed in this article. First, a multi-loop structure is designed with multiple time-scale analysis to make the system realizable. Then, to achieve the goal of accurate tracking, a sliding mode fault observer is added into each loop to accommodate the effects of all the uncertainties. This controller shows great applicability because of the simple structure. The only information the controller needs to know is the limits of uncertainties. In addition, since the above controller cannot guarantee robustness when the system model is unknown, an online adaptive estimation method is proposed to learn the parameter information. Stability of the overall closed-loop system is analyzed with the Lyapunov stability theory, and output tracks the expected trajectory. The simulation is presented with several situations (including adaptive estimation result test/robust test under parameter uncertainties and high-frequency noise/fault-tolerant ability under actuator faults) to verify the effectiveness and feasibility of the proposed scheme.

Fault Self-repairing Flight Control of a Small Helicopter via Fuzzy Feedforward and Quantum Control Techniques

In this paper, the longitudinal-lateral attitude control and fault self-repairing of a small helicopter is investigated using fuzzy feedforward and quantum control techniques. The Lagrange-Euler equation is used to derive a mathematical model of the helicopter flight dynamics. To handle the complex faults of the helicopter flight system, a model reference-based self-repairing control law is proposed using quantum control techniques, which can improve the helicopter’s self-repairing and control precision. In addition, a fuzzy feedforward compensation controller is designed to improve the anti-disturbance performance. Finally, simulation results are given to illustrate the effectiveness of the developed intelligent self-repairing controller.

Adaptive Controller Design for Faulty UAVs via Quantum Information Technology

In this paper, an adaptive controller is designed for a UAV flight control system against faults and parametric uncertainties based on quantum information technology and the Popov hyperstability theory. First, considering the bounded control input, the state feedback controller is designed to make the system stable. The model of adaptive control is introduced to eliminate the impact by the uncertainties of system parameters via quantum information technology. Then, according to the model reference adaptive principle, an adaptive control law based on the Popov hyperstability theory is designed. This law enable better robustness of the flight control system and tracking control performances. The closed-loop systems stability is guaranteed by the Popov hyperstability theory. The simulation results demonstrate that a better dynamic performance of the UAV flight control system with faults and parametric uncertainties can be maintained with the proposed method.

Direct self-repairing control for a helicopter via quantum multi-model and disturbance observer

In this paper, a new direct self-repairing control scheme is developed for a helicopter flight control system with unknown actuator faults and external disturbance. The design of multi-model-based adaptive control is used to accommodate the faulty system under different fault conditions. By appropriate switching based on quantum information technique, the system can be converted to the best model and the corresponding controller. Asymptotic model following performance and system stability is guaranteed. A disturbance observer is introduced to observe the disturbance of the system, which can produce corresponding control signals according to the disturbance. The results including a numerical simulation and a semi-physical verification demonstrate the effectiveness of the proposed self-repairing control approach for the helicopter flight control system.

Robust Adaptive Fault-Tolerant Control for Hypersonic Flight Vehicles with Multiple Faults

AbstractThis paper proposes a robust adaptive strategy for longitudinal dynamics of generic hypersonic flight vehicles with uncertainties and faults. Flight vehicles are generally subjected to disturbances and multiple faults, which should be compensated for to preclude performance degradation. To solve this problem, considering fast abrupt faults such as actuator stuck faults, an adaptive fault observer is added into the nominal dynamic inversion controller to accommodate the effects of faults with discrete function patterns. In addition, since the above observer is designed only for fast abrupt faults, an online support vector machine compensator is proposed to learn the state error caused by other faults. As the error contains both dynamic uncertainties and slow variation faults, additional controllers are not required to get rid of the unwanted faults. Stability of the overall closed-loop system is analyzed with the Lyapunov stability theory, and output tracks the expected trajectory. The simulation i...