Sliding Mode Flight Controller Research Articles

Sliding Mode Flight Control Law Design Requirements for Oblique Wing Aircraft Based on Perturbation Theory

Sliding Mode Flight Control Law Design Requirements for Oblique Wing Aircraft Based on Perturbation Theory

Fixed-time sliding mode flight control with model-based switching functions of quadrotor unmanned aerial vehicles

Fixed-time sliding mode flight control with model-based switching functions of quadrotor unmanned aerial vehicles

Fixed-time sliding mode flight control with model-based switching functions of quadrotor unmanned aerial vehicles

Fixed-time sliding mode flight control with model-based switching functions of quadrotor unmanned aerial vehicles

Design of sliding mode flight control system for a flexible aircraft

The evolution of large transport aircraft is characterized by longer fuselages and larger wingspans, while efforts to decrease the structural weight reduce the structural stiffness. Both effects lead to more flexible aircraft structures with significant aeroelastic coupling between flight mechanics and structural dynamics, especially at high speed, high altitude cruise. The lesser frequency separation between rigid body and flexible modes of flexible aircraft results in a stronger interaction between the flight control system and its structural modes, with higher flexibility effects on aircraft dynamics. Therefore, the design of a flight control law based on the assumption that the aircraft dynamics are rigid is no longer valid for the flexible aircraft. This paper focuses on the design of a flight control system for flexible aircraft described in terms of a rigid body mode and four flexible body modes and whose parameters are assumed to be varying. In this paper, a conditional integral based sliding mode control (SMC) is used for robust tracking control of the pitch angle of the flexible aircraft. The performance of the proposed nonlinear flight control system has been shown through the numerical simulations of the flexible aircraft. Good transient and steady-state performance of a control system are also ensured without suffering from the drawback of control chattering in SMC.

Erratum to “Fast Nonsingular Terminal Sliding Mode Flight Control for Multirotor Aerial Vehicles”

Due to a production error, in the original article [1], Figs. 1, 2 and 3 were incorrectly published. We apologize for this error. The correct figures, with their corresponding captions, are shown below: Fig. 1. Schematic representation of MAVs with fixed single (a) or double (b) rotors. Fig. 2. Hierarchical flight control architecture for MAVs with fixed rotors. PC: position controller; AC: attitude controller; CA 1, CA 2: control allocators. Fig. 3. Rotational control errors along the time (above) and in the phase plane (below).

Evaluation of Hunting-Based Optimizers for a Quadrotor Sliding Mode Flight Controller

The design of Multi-Input Multi-Output nonlinear control systems for a quadrotor can be a difficult task. Nature inspired optimization techniques can greatly improve the design of non-linear control systems. Two recently proposed hunting-based swarm intelligence inspired techniques are the Grey Wolf Optimizer (GWO) and the Ant Lion Optimizer (ALO). This paper proposes the use of both GWO and ALO techniques to design a Sliding Mode Control (SMC) flight system for tracking improvement of altitude and attitude in a quadrotor dynamic model. SMC is a nonlinear technique which requires that its strictly coupled parameters related to continuous and discontinuous components be correctly adjusted for proper operation. This requires minimizing the tracking error while keeping the chattering effect and control signal magnitude within suitable limits. The performance achieved with both GWO and ALO, considering realistic disturbed flight scenarios are presented and compared to the classical Particle Swarm Optimization (PSO) algorithm. Simulated results are presented showing that GWO and ALO outperformed PSO in terms of precise tracking, for ideal and disturbed conditions. It is shown that the higher stochastic nature of these hunting-based algorithms provided more confidence in local optima avoidance, suggesting feasibility of getting a more precise tracking for practical use.

A Specific Sliding Mode Control for Autopilot Design of Bank-to-Turn Missiles

This paper studies the BTT missile's sliding mode flight controller. Firstly, the control model is established according to dynamic inverse method and the general dynamic equation of the missile flying in the atmosphere. Then, the sliding mode controller is designed and it adopts the time-varying sliding mode surface, the self-defined reaching law and the adaptive control parameters. Finally, three sets of simulation are carried out to prove the flight controller designed in this paper for BTT missile can follow the guidance instructions and meet operational needs.

Integral Sliding Mode Flight Controller Design for a Quadrotor and the Application in a Heterogeneous Multi-Agent System

This paper investigates a novel integral sliding mode control (ISMC) strategy for the waypoint tracking control of a quadrotor in the presence of model uncertainties and external disturbances. The proposed controller has the inner–outer loop structure: The outer loop is to generate the reference signals of the roll and pitch angles, while the inner loop is designed by using the ISMC technique for the quadrotor to track the desired $x$ , $y$ positions and roll and pitch angles. The Lyapunov stability analysis is provided to show that the negative effects of the bounded model uncertainties and external disturbances can be significantly decreased. The designed controller is then applied to a heterogeneous multi-agent system (MAS) consisting of quadrotors and two-wheeled mobile robots (2WMRs) to solve the consensus problem. We present the control algorithms for the 2WMRs and quadrotors. Consensus of the heterogeneous MAS can be reached if the switching graphs always have a spanning tree. Finally, the experimental tests are conducted to verify the effectiveness of the proposed control methods.

Flight dynamic modeling and control for a telescopic wing morphing aircraft via asymmetric wing morphing

In this paper, a sliding mode flight controller is formulated in order to enhance the lateral maneuverability for a tailless telescopic wing morphing aircraft by using additional asymmetric wing telescoping. Based on the nonlinear time-varying equations of motion and the approximate aerodynamic model obtained by wind tunnel tests, a nonlinear time-varying model with coupling between aerodynamic parameters and control inputs is established and the open-loop dynamic response characteristics are analyzed. According to the difficulty of precise aerodynamic modeling during both sides of wing telescoping, the sliding mode control approach is used to design the control law to track maneuver reference command, which has a low requirement for modeling precision and is suitable for the nonlinear time-varying system. In addition, the control inputs are allocated to asymmetric wing telescoping and aerodynamic control surfaces based on the minimum energy method. The closed-loop simulation results of a roll agility maneuvering called “T90 maneuvering” are presented. The results show that a larger roll angular velocity is produced and the control surfaces in the maneuvering flight can maintain a large control margin, which means the maneuverability is significantly improved and the control burden of the aerodynamic control surfaces has been reduced compared with the aircraft without use of telescopic wings; moreover, the robustness of the sliding mode controller is verified by simulation of aerodynamic perturbations.

Adaptive backstepping sliding mode control for heavy-weight airdrop operations

This paper proposes an adaptive backstepping sliding mode flight control method that is compatible with heavyweight cargo airdrop. The goal is to maintain the plane states during cargo extraction process, in the presence of uncertainties of both constant and time-varying types, as well as matched and unmatched types. A backstepping sliding mode flight control law with parameter adaptation is presented based on the plane-cargo dynamics in strict-feedback form. The control approach consists in having an adaptation law that approximates the disturbance and uncertain aerodynamic function, which is separated from the complex nonlinearities. Also, the adaptation algorithm with projection can bound the estimated function. This ensures the robustness of the controller against time-varying disturbance and uncertainty. The convergence performance and robustness property of the control law are proved by the Lyapunov theory. The control effect is evaluated on a transport plane performing a maximum load airdrop task in a number of simulation scenarios.

Robust adaptive multivariable higher-order sliding mode flight control for air-breathing hypersonic vehicle with actuator failures

This article proposes an adaptive multivariable higher-order sliding mode control for the longitudinal model of an air-breathing vehicle under system uncertainties and actuator failures. Firstly, a fast finite-time control law is designed for a chain of integrators. Secondly, based on the input/output feedback linearization technique, the system uncertainty and external disturbances are modeled as additive certainty and the actuator failures are modeled as multiplicative uncertainty. By using the proposed fast finite-time control law, a robust multivariable higher-order sliding mode control is designed for the air-breathing hypersonic vehicle with actuator failures. Finally, adaptive laws are proposed for the adaptation of the parameters in the robust multivariable higher-order sliding mode control. Thus, the bounds of the uncertainties are not needed in the control system design. Simulation results show the effectiveness of the proposed robust adaptive multivariable higher-order sliding mode control.

Autonomous Aerial Refueling Modeling and Dynamic Inversion Adaptive Sliding Mode Control

A dynamic inversion adaptive sliding mode flight control method for autonomous aerial refueling (AAR) is approved in this paper. The drogue model and refueling aircraft 6-DOF nonlinear model is built. In order to improve the flight control precision and performance, the dynamic inversion control method is used to design the flight control law. Fuzzy adaptive control is combined with the sliding mode control is used to compensate the error of inversion, so the robustness and transient characteristic performance could be improved. The simulation results show that the AAR flight control has excellent control performance.

Tailless aircraft flight control using multiple time scale reconfigurable sliding modes

A triple time scale tailless aircraft flight control problem is addressed via continuous sliding mode control. A reconfigurable sliding mode flight controller is designed that achieves robust, high accuracy command angle tracking both before and after damage to an aircraft. Command angles and angular rate commands are robustly tracked in outer and inner loops correspondingly via finite reaching time continuous sliding mode controllers. An optimal control allocation algorithm is employed using nominal mathematical model of an aircraft. Sliding surface boundary layer reconfiguration (direct adaptation) is used in the "very" inner loop to account for actuator dynamics, deflection limits, and rate limits. Online damage identification is not required by this design. The reconfigurable sliding mode flight control technique is applied to a flight dynamics model of a tailless jet fighter that was developed under is the innovative control effectors program. Simulations demonstrate stability and high accuracy tracking performance without violation of actuator limits.