Guidance Of Unmanned Aerial Vehicles Research Articles

Design and development of an on-board autonomous visual tracking system for unmanned aerial vehicles

This paper proposes the design and development of an on-board autonomous visual tracking system (AVTS) for unmanned aerial vehicles (UAV). A prototype of the proposed system has been implemented in MATLAB/ Simulink for simulation purposes. The proposed system contains GPS/INS sensors, a gimbaled camera, a multi-level autonomous visual tracking algorithm, a ground stationary target (GST) or ground moving target (GMT) state estimator, a camera control algorithm, a UAV guidance algorithm, and an autopilot. The on-board multi-level autonomous visual tracking algorithm acquires the video frames from the on-board camera and calculates the GMT pixel position in the video frame. The on-board GMT state estimator receives the GMT pixel position from the multi-level autonomous visual tracking algorithm and estimates the current position and velocity of the GMT with respect to the UAV. The on-board non-linear UAV guidance law computes the UAV heading velocity rates and sends them to the autopilot to steer the UAV in the desired path. The on-board camera control law computes the control command and sends it to the camera's gimbal controller to keep the GMT in the camera's field of view. The UAV guidance law and camera control law have been integrated for continuous tracking of the GMT. The on-board autopilot is used for controlling the UAV trajectory. The simulation of the proposed system was tested with a flight simulator and the UAV's reaction to the GMT was observed. The simulated results prove that the proposed system tracks a GST or GMT effectively.

Design of an unmanned aerial vehicle based on acoustic navigation algorithm

Autonomous unmanned aerial vehicles (UAV) navigate using Global Positioning System (GPS). However, in places where GPS signals are interfered, or blocked (e.g., tunnel, downtown with high-rise buildings), auxiliary navigation systems are desirable. In this work, an acoustic based near field (< 1km) UAV guidance system is proposed. This system utilizes acoustic phase array mounted on UAV to provide direction of arrival estimates of narrow band acoustic sources at known locations. As such, the positions of UAV may be easily tracked. Through sensor fusion, this acoustic navigation system may also work together with GPS to provide even more accurate estimates.

Guidance Methodologies of Unmanned Aerial Vehicle Using Virtual Instrumentation Technique

The unmanned aerial vehicle guidance is very significant nowadays. Guidance of unmanned aerial vehicle generates commands to and controls the attitude to follow the reference trajectory. This paper presents a new guidance of unmanned aerial vehicle using virtual instrumentation technique. LabView is a system design platform and development environment for a visual programming language from national instruments and provides a virtual environment to guide the UAV in terms of bank angle and aileron angle. Aileron angle control the UAV roll degree of freedom and bank angle. In this method the guidance is considered under the atmospheric disturbance especially wind and. Aileron angle is used to direct the UAV against the wind. The gain of the system can also be controlled. Manual and automatic control of this vehicle is alsopossible.

Selecting a Flight Path of an UAV to the Ship in Preparation of Deck Landing

Objectives: Automatic landing of an aircraft-type Unmanned Aerial Vehicle (UAV) on the ship is a complex research and engineering problem. In the general case, a set of problems must be solved subject to the initial position of the UAV and the ship, weather, visibility, reliable radio communication etc. in preparation for landing and capturing the initial point of a glide path for landing. These problems include the UAV flying to the ship location, searching for and identifying the ship, determining rolling parameters and estimating the position of landing markers on the ship deck. Method: Methods of UAV guidance to the ship search area have been compared. Conditions for the effective application of various methods of UAV guidance to the ship have been determined. Findings: It was demonstrated that insufficient attention is paid in available research to scenarios, when the ship may change its direction and a communication channel with the UAV is not stable due to the weather. The following tasks are discussed: • determining conditions of physical realizability of the successful ship search; • selecting a method to guide the UAV towards the ship, with view to ship maneuverability intensity and duration of transmission breaks to the UAV about current ship parameters according to the flight endurance minimization criteria; and • determining UAV flight endurance to the ship location subject to the duration of transmission breaks. Conditions of the successful ship search have been determined and the ratio of the initial search area and UAV flight endurance has been shown. Improvements: The results of the study can be used in the development of autopilots for autonomous UAVs based on the ships.

Attitude Determination of Multirotor Aerial Vehicles Using Camera Vector Measurements

The employment of embedded cameras in navigation and guidance of Unmanned Aerial Vehicles (UAV) has attracted the focus of many academic researches. In particular, for the multirotor UAV, the camera is widely employed for applications performed in indoor environments, where the GNSS signal is often unreliable and electromagnetic interference can be a concern. In the literature, images are mostly adopted for position and velocity estimation, rather than attitude estimation. This paper proposes an attitude determination method for multirotor aerial vehicles using pairs of vector measurements taken from a downward-facing strapdown camera. The method is composed of three modules. The first one detects and identifies the visible landmarks by processing the images. The second module computes the vector measurements related to the direction from the camera to the landmarks. The third module estimates attitude from the vector measurements. In the last module, a version of the Multiplicative Extended Kalman Filter (MEKF) with sequential update is proposed as estimation method. The overall method is evaluated via Monte Carlo simulations, showing that it is effective in determining the vehicle's attitude and revealing its properties.

A Nonlinear Control Method for Autonomous Navigation Guidance

This paper deals with a nonlinear feedback control method based on Lie derivatives for the navigation guidance of unmanned aerial vehicles (UAVs). The paper proposes a modelling concept for planar and three-dimensional navigation together with proven algorithms to cope with the autonomous navigation along waypoints and on loiters. The steps that were performed in order to validate the autonomous navigation method are clearly described. The method was successfully validated on various realistic navigation scenarios for unmanned aircraft.

A Brief Survey on Bio-inspired Algorithms for Autonomous Landing∗∗The work is supported under IISc-DRDO collaborative project TR-DRDO-PAME-2015-05. The authors acknowledge Mr Ashutosh Simha, SERC, IISc for technical inputs and DRDO-FIST for the infrastructure provided.

The paper briefly introduces a few bio-inspired algorithms which can be applied to autonomous landing for Unmanned Aerial Vehicles (UAVs). A number of vision based data acquisition methodologies used for UAV navigation and guidance are described. Monocular camera based vision data can be used to extract plethora of information about the dynamics of a target plane in landing problems and also about the pose of the camera itself. Some recent, developments in the areas of autonomous landing and perching based on vision data from monocular camera are introduced. Some possible relevant extensions are also provided. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

Higher-order sliding mode based lateral guidance for unmanned aerial vehicles

A nonlinear sliding mode based scheme is developed for lateral guidance of unmanned aerial vehicles. The guidance and control system is considered as an inner and outer loop design problem, the outer guidance loop generates commands for the inner control loop to follow. Control loop dynamics is considered during derivation of the guidance logic, along with saturation constraints on the guidance commands. A nonlinear sliding manifold is selected for guidance logic design, the guidance loop generates bank angle commands for the inner roll control loop to follow. The real twisting algorithm, a higher order sliding mode algorithm is used for guidance logic design. Existence of the sliding mode along with boundedness of the guidance command is proved to ensure that controls are not saturated for large track errors. The proposed logic also contains an element of anticipatory or feed-forward control, which enables tight tracking for sharply curving paths. Efficacy of the proposed method is verified by flight testing on a scaled YAK-54 unmanned aerial vehicle. Flight results demonstrate robustness and effectiveness of the proposed guidance scheme in the presence of disturbances.

On the Guidance of Multiple UAV using a Centralized Formation Control Scheme and Delaunay Triangulation

This manuscript presents an application of the multi-layer control scheme to guide a formation of unmanned aerial vehicles (UAV) in positioning and trajectory tracking missions. In such case, each part of the formation control problem is dealt by an individual layer, which is independent module dealing with a specific part of the navigation problem. These layers are responsible to generate the desired path of the formation, to provide the desired posture of the robots, and to establish the control signal of each robot to reach their desired positions. The formation controller here introduced is able to coordinate the robots to the desired formation, including the possibility of time-varying position and/or shape, while a nonlinear underactuated controller previously proposed is responsible to guide the UAVs to their desired positions. The stability analysis of the closed-loop system is demonstrated in the sense of Lyapunov, resulting that the formation errors are ultimately bounded. In the sequel, a strategy to guide a formation of multiple unmanned aerial vehicles (MUAV) to accomplish positioning and trajectory-tracking tasks is also proposed. Delaunay triangulation is here used to split the platoon of UAVs in N-triangles, which are individually guided by the multi-layer control scheme (MLCS). The advantage of the MLCS in such proposal is the maintenance of the the Jacobian matrix order, regardless of the number of robots in the formation, which reduces the complexity of the control problem. Simulation results demonstrate the ability to accomplish the aforementioned tasks, thus validating the proposal.

Formation Flight of Multiple UAVs via Onboard Sensor Information Sharing.

To monitor large areas or simultaneously measure multiple points, multiple unmanned aerial vehicles (UAVs) must be flown in formation. To perform such flights, sensor information generated by each UAV should be shared via communications. Although a variety of studies have focused on the algorithms for formation flight, these studies have mainly demonstrated the performance of formation flight using numerical simulations or ground robots, which do not reflect the dynamic characteristics of UAVs. In this study, an onboard sensor information sharing system and formation flight algorithms for multiple UAVs are proposed. The communication delays of radiofrequency (RF) telemetry are analyzed to enable the implementation of the onboard sensor information sharing system. Using the sensor information sharing, the formation guidance law for multiple UAVs, which includes both a circular and close formation, is designed. The hardware system, which includes avionics and an airframe, is constructed for the proposed multi-UAV platform. A numerical simulation is performed to demonstrate the performance of the formation flight guidance and control system for multiple UAVs. Finally, a flight test is conducted to verify the proposed algorithm for the multi-UAV system.

Coordinated guidance for multiple UAVs

This paper addresses the path planning problem of multiple unmanned aerial vehicles (UAVs). The paths are planned to maximize collected amount of information from desired regions (DRs), while avoiding forbidden regions (FRs) and reaching the destination. This study focuses on maximizing collected information instead of minimizing total mission time, as in previous studies. The problem is solved by a genetic algorithm (GA) with the proposal of novel evolutionary operators. The initial populations are generated from a seed-path for each UAV. The seed-paths are obtained both by utilizing the pattern search method and by solving the multiple-Traveling Salesman Problem (mTSP). Utilizing the mTSP solves both the visiting sequences of DRs and the assignment problem of ‘which DR should be visited by which UAV?’ All of the paths in the population in any generation of the GA are constructed using a dynamical UAV model. Simulations are realized in a MATLAB/Simulink environment for different mission scenarios and the results provide physically realizable flight paths, which visit DRs and avoid FRs. Real-world experiments are conducted by using small UAVs, which are constructed by autopilot integration on model airplanes. Flight tests performed based on simulated scenarios proved beneficial in maximizing the collected amount of information for multiple UAV missions.

Robust Model Predictive Control of Unmanned Aerial Vehicles Using Waysets

This paper introduces a new formulation of model predictive control for robust trajectory guidance of unmanned aerial vehicles. It generalizes the ubiquitous concept of waypoints to waysets, in order to provide robustness to bounded state disturbances in the presence of obstacles. Using a variable horizon formulation of model predictive control, it shows how wayset guidance combined with constraint tightening can guarantee robust recursive feasibility and finite-time completion of a control maneuver. Simulations on a point mass fixed-wing unmanned aerial vehicle model moving through a field of obstacles with wind disturbances demonstrate significant computational benefits from using waysets when compared to existing mixed-integer optimization methods that employ long prediction horizons. Using the controller’s robustness to mitigate linearization error, an additional example implements the strategy on a simulated quadrotor, demonstrating how waysets can be used to control more complex nonlinear systems.

Design of Fuzzy Neural Network Guidance Law Based on TakagiSugeno for UAV

Guidance of unmanned aerial vehicle (UAV) in three-dimensional space was studied in this paper. We designed a three-dimensional fuzzy neural network guidance law with the fuzzy rules of Takagi-Sugeno that based on proportional guidance principle and put the characteristics of the fuzzy neural network control into use. We decomposed the 3-D tracking trajectory into two two-dimensional planes and guided respectively, and took the influence of target mobility for guidance trajectory into consider. The design of guidance law was using the principle of proportional guidance, based on the Takagi-Sugeno type fuzzy inference, we took horizontal line of approaching velocity of missile-to-target, vertical line of sight angle velocity and sight angle velocity as inputs of fuzzy neural network, and yaw and pitch acceleration commands of UAV are the outputs, then we simulated the seeker tracking process against the target doing uniform motion in a straight line, curve movement and uniform circular motion respectively for UAV. Verified by simulation in this paper, the effect of the design of guidance law is ideal, and the proposed law is superior to the others and has good effect in response to the maneuvering target, and guidance trajectory is smoother.

3D Guidance of Unmanned Aerial Vehicles Using Sliding Mode Approach

3D Guidance of Unmanned Aerial Vehicles Using Sliding Mode Approach

Lateral track control of UAVs using the sliding mode approach: from design to flight testing

This paper develops sliding-mode-based nonlinear logic for guidance of unmanned aerial vehicles (UAVs) for curved and straight path following. UAV trajectories generally consist of straight path segments, curved arcs, circular loiters and other manoeuvres; tight ground track control is desired throughout the trajectory. This is achieved by controlling the lateral (cross-track) deviation of the vehicle in flight. The main objective of the guidance algorithm is to keep the lateral track error of the vehicle as small as possible while performing graceful and stable manoeuvres despite the presence of uncertainties and disturbing winds. Lateral track control is usually achieved by banking the vehicle, that is, by executing roll manoeuvres. The scheme must perform well without saturating the roll angle of the vehicle, which serves as the control input for the guidance algorithm. The algorithm proposed here is shown to perform well for both straight and circular path tracking while ensuring control boundedness, and hence no saturation. Crosswinds are a major source of disturbance for the guidance problem. This is incorporated into the design formulation and guidance gains are selected to provide the desired performance despite the presence of disturbing winds. A sliding-mode-based scheme is developed which includes a feedforward component related to the rate of change of the desired path heading. Stability of the algorithm is proved using an appropriate Lyapunov function. The algorithm is implemented in the flight control computer of a scaled YAK-54 research aircraft; flight test results are presented and compared with those from other guidance algorithms. Flight results demonstrate the effectiveness and performance of the proposed guidance scheme. The algorithm considers guidance in the 2D lateral plane only and minimizes deviations from the desired ground track of the vehicle.

Vision-Based Detection and Tracking of a Mobile Ground Target Using a Fixed-Wing UAV

This paper presents a framework for tracking a mobile ground target (MGT) using a fixed-wing unmanned aerial vehicle (UAV). Challenges from pure theories to practical applications, including varying illumination, computational limits and a lack of clarity are considered. The procedure consists of four steps, namely: target detection, target localization, states estimation and UAV guidance. Firstly, the MGT in the wild is separated from the background using a Laplacian operator-based method. Next, the MGT is located by performing coordinate transformations with the assumption that the altitude of the ground is invariant and known. Afterwards, a Kalman filter is used to estimate the location and velocity of the MGT. Finally, a modified guidance law is developed to guide the UAV to circle and track the MGT. The performance of our framework is validated by simulations and a number of actual flight tests. The results indicate that the framework is effective and of low computational complexity, and in particular our modified guidance law can reduce the error of the tracking distance by about 75% in specified situations. With the proposed framework, such challenges caused by the actual system can be tackled effectively, and the fixed-wing UAV can track the MGT stably.

Dynamic Inversion-Based Nonlinear Aiming Point Guidance of Unmanned Aerial Vehicles for Reactive Obstacle Avoidance

A dynamic inversion-based three-dimensional nonlinear aiming point guidance law is presented in this paper for reactive collision avoidance of unmanned aerial vehicles. When an obstacle is detected in the close vicinity and collision is predicted, an artificial safety sphere is put around the center of the obstacle. Next, the velocity vector of the vehicle is realigned towards an 'aiming point' on the surface of the sphere in such a way that passing through it can guarantee safe avoidance of the obstacle. The guidance command generation is based on angular correction between the actual and the desired direction of the velocity vector. Note that the velocity vector gets aligned along the selected aiming point quickly (i.e., within a fraction of the available time-to-go), which makes it possible to avoid pop-up obstacles. The guidance algorithm has been verified with simulations carried out both for single obstacles as well as for multiple obstacles on the path and also with different safety sphere sizes around the obstacles. The proposed algorithm has been validated using both kinematic as well as point mass model of a prototype unmanned aerial vehicle. For better confidence, results have also been validated by incorporating a first-order autopilot models for the velocity vector magnitude and directions.

Research of Integrated Design about Guidance and Control of Homing UAV

Integrated design about guidance and control of homing unmanned aerial vehicle (UAV) is proposed. Firstly, an integrated guidance and control model with uncertainties can be described. Secondly, a nonlinear observer is designed for the integrated guidance and control model. Finally, the simulation results show that the nonlinear adaptive guidance law using the proposed integrated design model can perform better than the one designed separately.

Differential Geometry based Collision Avoidance Guidance for Multiple UAVs

A guidance law based on a differential geometry is proposed for UAV(Unmanned Aerial Vehicle) collision avoidance and formation reconfiguration. The proposed guidance law makes multiple UAVs avoid obstacles and provides a guideline for formation reconfigurtion. Differential geometry uses the line of sight vector and relative velocity vector information, and therefore it is effective to generate the real-time guidance command. Recognition process is introduced for obstacle recognition and judgement whether or not the collision avoidance is completed. Lyapunov theorem is used to prove the stability of the proposed guidance law. The analysis on the collision avoidance is also performed using the maximum angular rate of the UAV and the range of the recognition. Numerical simulation is performed to verify the performance of the proposed guidance and formation reconfiguration strategy.

Aerodynamic Model Analysis and Flight Simulation Research of UAV Based on Simulink

Mathematical simulation method can be adopted to check flight characteristic of UAV, also can be adopted to simulate hardware experiments of unmanned aerial vehicle (UAV), then related flight experiments can be performed. The simulation method can reduce the flight periods, cost and risk. UAV flight model research play an important role in simulation and modeling in initialize periods of the UAV producing. The study of the paper focuses on the aerodynamic force modeling work of UAV based on Simulink. The designed model not only can afford mathematics simulation experiment but also will do benefits to the research of flight control, navigation guidance of UAV.