Autonomous Flight Control System Research Articles

Autonomous flight performance maximization for slung load carrying rotary wing mini unmanned aerial vehicle

PurposeThis research study aims to minimize autonomous flight cost and maximize autonomous flight performance of a slung load carrying rotary wing mini unmanned aerial vehicle (i.e. UAV) by stochastically optimizing autonomous flight control system (AFCS) parameters. For minimizing autonomous flight cost and maximizing autonomous flight performance, a stochastic design approach is benefitted over certain parameters (i.e. gains of longitudinal PID controller of a hierarchical autopilot system) meanwhile lower and upper constraints exist on these design parameters.Design/methodology/approachA rotary wing mini UAV is produced in drone Laboratory of Iskenderun Technical University. This rotary wing UAV has three blades main rotor, fuselage, landing gear and tail rotor. It is also able to carry slung loads. AFCS variables (i.e. gains of longitudinal PID controller of hierarchical autopilot system) are stochastically optimized to minimize autonomous flight cost capturing rise time, settling time and overshoot during longitudinal flight and to maximize autonomous flight performance. Found outcomes are applied during composing rotary wing mini UAV autonomous flight simulations.FindingsBy using stochastic optimization of AFCS for rotary wing mini UAVs carrying slung loads over previously mentioned gains longitudinal PID controller when there are lower and upper constraints on these variables, a high autonomous performance having rotary wing mini UAV is obtained.Research limitations/implicationsApproval of Directorate General of Civil Aviation in Republic of Türkiye is essential for real-time rotary wing mini UAV autonomous flights.Practical implicationsStochastic optimization of AFCS for rotary wing mini UAVs carrying slung loads is properly valuable for recovering autonomous flight performance cost of any rotary wing mini UAV.Originality/valueEstablishing a novel procedure for improving autonomous flight performance cost of a rotary wing mini UAV carrying slung loads and introducing a new process performing stochastic optimization of AFCS for rotary wing mini UAVs carrying slung loads meanwhile there exists upper and lower bounds on design variables.

Design of an autonomous flight control system for imitation falcon flapping-wing aircraft

Bionic flapping-wing aircraft is a new type of aircraft with broad application prospects in the civil and military fields due to their low noise, good concealment, strong maneuverability, and high energy efficiency. The autonomous flying ability of bionic flapping-wing aircraft is the key to improving their flight efficiency. Although autonomous flight research on aircraft at home and abroad have made some achievements, few researchers have conducted corresponding studies on bionic flapping-wing aircraft. The unique driving structure of the bionic flapping-wing aircraft introduces great challenges to research on its autonomous flight control. In this paper, an autonomous flight control system is designed on the research platform of falcon flapping-wing aircraft. In consideration of the load problem of falcon flapping-wing aircraft, the hardware system is designed based on an STM32 microchip. A linear/nonlinear switching guidance algorithm is proposed considering the guidance accuracy and operation speed, due to the limited computing power of microcomputing platforms. Simulations prove that the proposed algorithm is more suitable for imitation falcon flapping-wing aircraft than linear guidance and nonlinear guidance algorithms. A cascade PID controller for roll angle and height is designed in consideration of the mechanism lag of falcon flapping-wing aircraft. By using this approach combined with ground station software for the imitation falcon flapping-wing aircraft, the task of autonomous fixed-height arc trajectory tracking based on imitation falcon flapping-wing aircraft is finally realized.

Autonomous Guidance and Flight Control on a Partial-Authority Black Hawk Helicopter

An autonomous guidance and flight control system was integrated and flight tested on a Black Hawk helicopter as part of an effort to provide all weather capability for U.S. Army fleet rotorcraft. The guidance and flight-control system components were previously flight tested on a full-authority helicopter, and were adapted to fly on the partial-authority test helicopter of this paper. The main autonomy guidance components consisted of the Risk Minimizing Obstacle Field Navigation algorithm, Safe Landing Area Determination algorithm, Mission Manager, and Integrated Cueing Environment. These components provided reactive obstacle avoidance guidance, landing site selection, pilot/autonomy interaction, and pilot situational awareness for degraded visual environments. In addition to the autonomy components, the Autonomous Partial-Authority Flight Control System provided a fully stabilized path-following capability to the guidance components. This paper describes how these components were adapted to a partial-authority helicopter that is typical of the current U.S. Army fleet. To test the system, a laser detection and ranging unit was used as a surrogate ranging device in lieu of an all-weather sensor system that was concurrently under development. Flight test results are presented from the fully integrated system navigating through terrain, selecting landing sites, and autonomously landing, while simultaneously keeping the pilot situationally aware of the autonomy’s intent.

Adaptive Learning-Based Observer With Dynamic Inversion for the Autonomous Flight of an Unmanned Helicopter

This article presents the development of an autonomous flight control system for a small-scale unmanned helicopter based on an online adaptive learning-based observer and model predictive control (MPC). The adaptive learning-based observer provides an approximate dynamic inversion for solving the coupled dynamic problem. The discrete-time MPC (DMPC) uses a prediction process to obtain a stable model. The Laguerre function, a state observer, and a recursive learning algorithm were integrated into DMPC, the core of the flight control system. Exponential data weighting was adopted to increase the stability of the designed flight control system. By integrating these approaches, an adaptive learning-based flight control system, which consists of the pitch, roll, yaw, and heave controllers, is presented to evaluate the stability and performance of the proposed autonomous flight control system of an unmanned helicopter. Moreover, an adaptive controller based on neural approximation for yaw motion is used to improve the performance of yawing control of the helicopter. In order to validate the feasibility of the proposed method, a hardware-in-the-loop simulation was performed in real time. The system included an embedded system, a self-developed users interface, and the X-plane flight simulator. The simulation results showed that the flight control system was able to maintain the position and the attitude of the helicopter in hover mode under the influence of wind gust and disturbance. The proposed method had better performance than a robust control system, in both ideal and disturbed environments.

Application of robust H-infinity controller in transition flight modeling of autonomous VTOL convertible Quad Tiltrotor UAV

PurposeThis paper aims to provide a mathematical modeling and design of H-infinity controller for an autonomous vertical take-off and landing (VTOL) Quad Tiltrotor hybrid unmanned aerial vehicles (UAVs). The variation in the aerodynamics and model dynamics of these aerial vehicles due to its tilting rotors are the key issues and challenges, which attracts the attention of many researchers. They carry parametric uncertainties (such as non-linear friction force, backlash, etc.), which drives the designed controller based on the nominal model to instability or performance degradation. The controller needs to take these factors into consideration and still give good stability and performance. Hence, a robust H-infinity controller is proposed that can handle these uncertainties.Design/methodology/approachA unique VTOL Quad Tiltrotor hybrid UAV, which operates in three flight modes, is mathematically modeled using Newton–Euler equations of motion. The contribution of the model is its ability to combine high-speed level flight, VTOL and transition between these two phases. The transition involves the tilting of the proprotors from 90° to 0° and vice-versa in 15° intervals. A robust H-infinity control strategy is proposed, evaluated and analyzed through simulation to control the flight dynamics for different modes of operation.FindingsThe main contribution of this research is the mathematical modeling of three flight modes (vertical takeoff–forward, transition–cruise-back, transition-vertical landing) of operation by controlling the revolutions per minute and tilt angles, which are independent of each other. An autonomous flight control system using a robust H-infinity controller to stabilize the mode of transition is designed for the Quad Tiltrotor UAV in the presence of uncertainties, noise and disturbances using MATLAB/SIMULINK. This paper focused on improving the disturbance rejection properties of the proposed UAV by designing a robust H-infinity controller for position and orientation trajectory regulation in the presence of uncertainty. The simulation results show that the Tiltrotor achieves transition successfully with disturbances, noise and uncertainties being present.Originality/valueA novel VTOL Quad Tiltrotor UAV mathematical model is developed with a special tilting rotor mechanism, which combines both aircraft and helicopter flight modes with the transition taking place in between phases using robust H-infinity controller for attitude, altitude and trajectory regulation in the presence of uncertainty.

Capture of UAVs Through GPS Spoofing Using Low-Cost SDR Platforms

The increased use of unmanned aerial vehicles (UAVs), better known as drones, by civilians has grown exponentially and their autonomous flight control systems have improved significantly, which has resulted in a greater number of accidents and dangerous situations. To help resolve this problem, in this paper, we address the use of low-cost Software Defined Radio (SDR) platforms for simulating a global navigation satellite system (GNSS), more specifically the global positioning system (GPS), in order to transmit false signals and induce a location error on the targeted GPS receiver. Using this approach, a defensive system can be implemented which can divert, or even take control of unauthorized UAVs whose flight path depends on the information obtained by the GPS system.

Comparison of black-grey-white box approach in system identification of a flight vehicle

Developing an autonomous flight control system for a fixed-wing unmanned aerial vehicle (UAV) requires the mathematical representation of the system dynamics which can be obtained through system identification, such as using white, grey or black box methods. In this paper, three system identification methods; white method modeling using Cook formulas which is used analytically to develop the linear-time-invariant model structure with the aerodynamic coefficients of the UAV extracted from Missile DATCOM computations at certain flight conditions, and two empirical mathematical models constructed from non-linear flight simulator defined as the Greyification of Black Box Model (B2G) and Direct Grey to White Linkage (G2W). The comparison shows that both empirical methods prove to be very instrumental to contrast and produce higher sense of engineering than the analytical one

Correlation of Hardware in the Loop Simulation (HILS) and real control vehicle flight test for reducing flight failures

After development of simulation system in laboratory tests has been completed, before implementing an autonomous flight control system directly in a high speed UAV, the system needs to be tested in a ‘transitional’ vehicle namely Clouds aeromodeling, to make sure all devices of the control system function well in manual mode, stability and auto pilot by way point. Compatibility of setting gain PID in the simulation test with the real flight test becomes a challenge to ensure the success of the vehicle in flying, as probability of flight failures or target missing is reduced. This research has successfully proven the compatibility of the gain PID in an auto pilot by way point flight condition.

Development of the algorithm for aircraft control at inaccurate measurement of the state vector and variable accuracy parameter

A parametric method of the synthesis of control in the closed circuit, taking into account explicitly generalized error of the inertial module, is presented. The law of control in the form of analytical formulas is typically assigned to the control program and does not change during flight of an unmanned aerial vehicle. This decreases the capabilities of the autonomous flight control system to overcome control errors, which occur for various reasons. To verify assumptions about a possibility of improving the accuracy of an aerial vehicle control by the data of the strapdown inertial navigation system on a certain time interval of autonomous operation, the calculation experiment was conducted with the use of the developed software complex, simulating operation of the automatic flight control system. Parametrization of the law of control is considered as the main contribution (the outcome). Introduction of the parameter made it possible to decrease a negative impact of measurement errors and other disturbing factors on accuracy of reaching by the point of flight destination. Through computer modeling, it was shown that it is possible to decrease the impact of a generalized measurement error on generation of values of control functions by changing the value of the parameter. Analytical expressions for the estimation of accuracy of automatic control at the known generalized error of the inertial module and limited disturbing influences were obtained. After analyzing the influence of these factors on accuracy of the object control, a set of recommendations on selection of a variable parameter of synthesis of control depending on precision level of the sensors, used in the inertial module of measuring sensors, was generated.

Autonomous flight control system of quadrotor and its application to formation control with mobile robot

Abstract This paper presents an autonomous flight control system of a quadrotor ARdrone 2.0 only using the internal sensor. Since AR.Drone is designed as a quadrotor with four control commands, four velocity models are constructed by the step response experiments. The basic control laws designed by LQR are combined with each other to construct the complex control system for required flight missions. Furthermore, the proposed autonomous flight control system is applied to a formation control with a mobile robot. The effectiveness of the proposed autonomous flight control system is demonstrated in experiments.

Research on visual autonomous navigation indoor for unmanned aerial vehicle

The aim of this paper is to study visual autonomous navigation of unmanned aerial vehicle (UAV) in indoor global positioning system (GPS) denied environment. The UAV platform of the autonomous navigation flight control system is designed and built. The principle of visual localization and mapping algorithm is studied. According to the characteristics of UAV platform, the visual localization is designed and improved. Experimental results demonstrate that the UAV platform can realize the tasks of autonomous localization, navigation and mapping based on visual in unknown environments.

A synthesis of autonomous flight control system for a drone

A synthesis of autonomous flight control system for a drone

スライディングモード制御を用いたクアッドコプターの自立飛行に関する研究

This study discusses the practical usefulness of Sliding Mode Control (SMC) in application to a quad-rotor vehicle as an autonomous flight control system. SMC shows high robustness to disturbances and modeling errors in theoretical conditions, where control inputs are assumed to be switched in a very high frequency. However in real systems, control input is calculated after a specified time interval, and furthermore rotors of vehicles have time delays due to motor's time constants. Thus, it is not clear that SMC systems can keep flying stability and robustness to disturbances and errors. In this paper, the effects of time interval of SMC and time constants of rotors are investigated in numerical simulations as a preliminary study of experiments.

425 小型無人飛行装置AR. Droneの自律飛行制御法の研究(GS4-3 移動ロボット・モジュールロボット)

425 小型無人飛行装置AR. Droneの自律飛行制御法の研究(GS4-3 移動ロボット・モジュールロボット)

253 AR.Droneを利用した自律飛行動作システムの検討

253 AR.Droneを利用した自律飛行動作システムの検討

Control System Design of a Hex-Rotor Aircraft Based on the Neural Network Sliding Mode Method

For the existing Multi-rotor aircrafts, the under-actuation and strong coupling characteristics have a remarkable influence on their flight performance. In order to overcome this effect, a novel Hex-Rotor aircraft is proposed in this paper. Based on the unique configuration of its six driving rotors, the Hex-Rotor aircraft has the ability to achieve the real independent control on the space 6-DOF channels. An autonomous flight control system with neural network sliding mode is designed. The simulation proved that the novel Hex-Rotor aircraft has desired maneuvering capability,and thehe control system is able to guarantee the aircrafts tracking flight of the aircraft.

Design Analysis of Autonomous Air Traffic Flight Control System

Software architectural design, also known as top-level design, describes the software top-level structure and organization and identifies the various components. The concept of an automated air traffic flight control system which controls airplanes requires a high degree of operational integrity and availability. One possible solution to alleviate air travel congestion could be the automation of air traffic control and allowing it to have direct control over airplane flight paths. Such a system would, in theory, reduce the workload of the flight crew and the air traffic controllers, as well as increase traffic flow. This paper presents several analyses of such a conceptual system from a net-centric perspective. First, the systems operation is described from the context of a flight, to provide a basis for the discussion of various system models and views. Spiral development model stages as well as related events which occur during system design give an idea of how the system would be developed incrementally. Formal methods can be used to improve software security but can be costly and also have limitations of scale, training, and applicability. To compensate for the limitations of scale, formal methods can be applied to selected parts or properties of a software project, in contrast to applying them to the entire system. The concept of object-oriented development (OOD) has gradually matured from being presented. The OOD can still be regarded as one of the mainstream development models. UML includes a standardized graphical notation used to create an abstract model of a system, referred to as a UML model. We describe AATFCS system with UML modeling techniques. AADL is an extensible and allows us to introduce new properties; we can define a set of properties specific to the data state variable. In this paper we present the AADL language for AATFCS system.

EFFECTS OF PROPELLER BLADE TWIST ON RECONNAISSANCE QUAD-ROTOR UAV

ABSTRACTRotors play a pivotal role in the overall performance of a rotary-wing aircraft. Forcesand moments required for flight are achieved through effective, compact and high-liftrotor design. Important rotor parameters are thrust, power and torque, which arefunctions of blade twist and rotor radius. A robust and efficient rotary-wing UAV flightcontrol system must provide the vehicle with the ability to perform safe flightmanoeuvres. This comprise normal flight conditions and proportionate regulation ofthrust in response to the variation in power demand, which comes to play due tochanges in aerodynamics conditions within the vehicle operating environment. Thispaper presents an in-depth analysis on the effect of variations of propeller blade twistand diameter with the view to designing an autonomous flight control system for amicro rotary-wing UAV. Virtual Blade Model (VBM) was used for the analysis and theresult validated using a quad-rotor vehicle. The study comes up with an efficientpropeller choice suitable for autonomous reconnaissance quad-rotor UAV.

Hex-Rotor无人飞行器及其飞行控制系统设计

A novel Hex-Rotor aircraft was proposed to overcome the effect of under-actuation and strong coupling characteristics on the flight performance of existing multi-rotor aircrafts.Based on the unique configuration of six driving rotors,the Hex-Rotor aircraft has the ability to control the space 6-DOF channels independently.First,the structures and characteristics of the Hex-Rotor aircraft were introduced and its dynamic model was established.Then,an autonomous flight control system with a parallel double-loop structure was designed,in which the command-filter backstepping approach was introduced into the attitude stability augmentation control loop,and the translational controller based on the active disturbance rejection control technique was used in the position loop.Finally,the total independent control of the aircraft on 6-DOF channels was achieved in the numerical simulation and the influences of unknown external disturbances and model uncertainties on the flight control performance were overcome.The prototype experiment results indicate that the horizontal tracking errors,altitude errors and attitude errors for the aircraft are limited in ±4 m,±3 m,and ±0.05 rad,respectively,which are all according with the precision ranges of measurement units and mean that the prototype has tracked the reference translational and attitude commands accurately.The simulation and experimental results verify that the designed Hex-Rotor aircraft has desired maneuvering capability,and the control system is able to guarantee the autonomous tracking flight of the aircraft.

2A2-J10 屋内飛行のための回転式揺動装置付測域センサ搭載飛行ロボット(飛行ロボット・メカトロニクス(2))

In case of disasters or accidents, such as earthquake, typhoon, and critical accidents, it may be occurred danger area that people can't enter. The areas may interfere with rescue work and wreak further damage. Flying robot which can move three-dimensionally and fly low altitude and narrow place is expected to play an important role in such disaster areas. The purpose of this study is to develop indoor autonomous flight control system using three-dimensional mapping by Laser Range Finder(LRF). If the LRF is fixed, in order to scan three-dimensionally, it is needed that flying robot to be able to move up and down. So in this study, we add roundly swing device that can scan three-dimensionally without moving up and down to flying robot.