Hybrid UAV Research Articles

Sampling-Based Planning for Guaranteed Safe Energy Management of Hybrid UAV Powertrain Under Complex, Uncertain Constraints

Sampling-Based Planning for Guaranteed Safe Energy Management of Hybrid UAV Powertrain Under Complex, Uncertain Constraints

Performance evaluation and energy management strategy of drone methanol reforming fuel cell hybrid power system: A case study

The performance of hydrogen production by methanol steam reforming and high temperature proton exchange membrane fuel cells on drone lacks the comparison of experimental data, resulting in the overall performance improvement of the system is difficult to evaluate. Therefore, the energy management strategy of methanol reforming high temperature proton exchange membrane fuel cell hybrid power system and state machine is designed and optimized. The performance of this system is analyzed and compared with the flight experiment data of a proton exchange membrane fuel cell hybrid UAV. The results show that the SOC of the system can be stabilized between 70 and 80 during the long cruise phase. The test results show that the maximum hydrogen storage mass density of the hydrogen supply system is increased by 67.6%. The flight time of the system under economic cruise flight of the drone is improved by 29.1%–44.9% with different quality of fuel. Under the maximum flight speed of a certain wind speed, the system can meet the flight requirements and increase the flight time by 31.9% and 17.6% respectively under the wind speed of 1.5 m/s and 4 m/s. Its flight time has been greatly improved, and it has great potential as a drone system.

Nonlinear modeling and designing transition flight control scenarios for a dual thrust hybrid UAV

Nonlinear modeling and designing transition flight control scenarios for a dual thrust hybrid UAV

Research on the design of direct-drive permanent magnet generator for hybrid UAV

As the core of the power system, the performance of the generator is crucial to the flight and operation of the drone. This paper introduces the design and research of a direct-drive permanent magnet generator for gasoline-electric hybrid UAV. A computationally efficient optimization design method was proposed, and the generator used in the 25 kg UAV was designed

Real-Time Nonlinear Control Allocation Framework for Vehicles with Highly Nonlinear Effectors Subject to Saturation

Hybrid Unmanned Aerial Vehicles UAV are vehicles capable of take-off and landing vertically like helicopters while maintaining the long-range efficiency of fixed-wing aircraft. Unfortunately, due to their wing area, these vehicles are sensitive to wind gusts when hovering. One way to increase the hovering wind-rejection capabilities of hybrid UAV is through the addition of extra actuators capable of directing the thrust of the rotors. Nevertheless, the ability to control UAVs with many actuators is strictly related to how well the Control Allocation problem is solved. Generally, to reduce the problem complexity, conventional (CA) methods make use of linearized control effectiveness in order to optimize the inputs that achieve a certain control objective. We show that this simplification can lead to oscillations if it is applied to thrust vectoring vehicles, with pronounced non-linear actuator effectiveness. When large control objectives are requested or actuators saturate, the linearized effectiveness based CA methods tend to compute a solution far away from the initial actuator state, invalidating the linearization. A potential solution could be to impose limits on the solution domain of the linearized CA algorithm. However, this solution only reduces the oscillations at the expense of a lag in the vehicle acceleration response. To overcome this limitation, we present a fully nonlinear CA method, which uses an Sequential Quadratic Programming (SQP) algorithm to solve the CA problem. The method is tested and implemented on a single board computer that computes the actuator solution in real time onboard a dual axis tilting rotor quad-plane. Flight test experiments confirm the problem of severe oscillations in the linearized effectiveness CA algorithms and show how the only algorithm able to optimally solve the CA problem is the presented Nonlinear method.

Effect of flight level to maximum power utilization for PEMFC/supercapacitor hybrid uav with switched reluctance motor thruster

In this study, the performance of a fixed-wing PEMFC/SC hybrid UAV with an SRM thruster is investigated by different flight levels. Flight levels negatively affect the PEMFC due to changing ambient conditions such as air temperature and pressure. Hence, the international standard atmosphere (ISA) model for PEMFC voltage-current-power ratings is derived with 100 m intervals for 0–7500 m. The demanded electrical power by UAV increases at high altitudes due to the compressor used for air pressurization of PEMFC. Therefore, a maximum power point tracking (MPPT) model of PEMFC should be utilized in case of overshooting the maximum power level that can be provided. While the main power source of the UAV is PEMFC, the auxiliary power source is SC. The SC is preferred for DC bus voltage stabilization, avoiding maximum power point overshoot, and preventing high instantaneous current that shortens the lifespan of PEMFC. The proposed UAV model is verified at MATLAB/Simulink and the results prove that the system is satisfying.

Design and Innovative Integrated Engineering Approaches Based Investigation of Hybrid Renewable Energized Drone for Long Endurance Applications

At present, surveillance is attracting attention in the field of UAV development. In particular, border surveillance plays a vital role in obtaining the required data around the border and for assisting in military operations. The primary function of this Hybrid UAV (VTOL and Fixed Wing) is to provide prerequisite data, captured during day/night surveillance, to the respective database. One of the primary problems that arise in border patrolling is the use of the UAV under different environmental conditions, thereby reducing its endurance firmly. In addition to the surveillance equipment, energy harvesting techniques are involved in solving the problem of endurance. The piezoelectric energy harvester and solar panels are added to harvest electrical energy in the UAV. Based on this application, the conceptual design of the Hybrid UAV, based on nature, was designed and investigated theoretically, as well as computationally. A series of analysis, which includes Computational Fluid Dynamics, Finite Element Analysis and Analytical approach, was used to determine the energy harvested from the energy harvester. This work confirms the proposed integrated engineering approach for the estimation of renewable energy, via PVEH patches, and the same approach is thus offered to researchers for subsequent applications. Additionally, a hybrid energy idea for newly developed drones was proposed in this work. This concept will be extensively used in the unmanned aircraft system sectors.

Control of Hybrid Transitioning Morphing-wing VTOL UAV

Hybrid UAV has combined characteristics of fixed-wing UAV and multi-rotor UAVs. Fixed-wing UAV has higher flight endurance, while the multi-rotor UAV requires no runways and can also perform vertical take-off and landing. Hybrid morphing wing UAV has ability to perform mission both as quadcopter and fixed-wing aircraft combined in efficient manner. This paper discusses the flight capability of a hybrid UAV that can transition between fixed-wing and quadcopter mode of flight. Dynamic equations of the hybrid UAVs are presented. The paper proposes a single non-linear controller with ability to handle the two different flight modes. The proposed controller uses a novel backstepping method and quaternion formulation, as transition between Euler angles provides problems like singularities. Although, backstepping has been used in various control design,it is unique to use backstepping that handles the complex vehicle transition phase along with use of quaternions. The performance of the proposed scheme is demonstrated via numerical simulations.

Double Hybrid Tailsitter Unmanned Aerial Vehicle With Vertical Takeoff and Landing

We propose a new double-hybrid concept and architectural design of a tailsitter unmanned aerial vehicle with vertical takeoff and landing capability. Basically, it consists of a modified flying wing with a single combustion powertrain set and a multirotor with 2 powertrain sets with electric motors. With the electric propellers fixed at the leading wing edge, the tailsitter has two standard surfaces for elevation control and two vertical stabilizers that are used to give the necessary direction on vertical takeoff and landing. We have designed, built, and tested a prototype based on this new double-hybrid concept, which spends less energy on vertical taking off and landing and also on horizontal flight, thus maximizing flight endurance and travelled distance. We performed several experimental tests starting with the aircraft on the ground in vertical positioning. These tests include executing vertical takeoffs and landing, transitions from vertical to horizontal flight modes and transitions back (from horizontal to vertical), and hovering, which were carried out successfully. Transitions fourth and back from combustion to multirotor are inherent to some of those flight mode transitions, which have also been performed smoothly. We also performed tests (in bench) to estimate the maximum flight duration, which has demonstrated about 32 minutes of endurance. To this end, the proposed and currently built double-hybrid prototype has proven to be functional as an effective hybrid UAV system.

Improved Flight Dynamics of a Fuel-Cell Powered Hybrid UAV with a Cyclorotor

Improved Flight Dynamics of a Fuel-Cell Powered Hybrid UAV with a Cyclorotor

Hierarchical model-based predictive controller for a hybrid UAV powertrain

The emerging trend of vehicle electrification is transforming the transportation industry by replacing traditional mechanical and hydraulic components with higher performing, more reliable, and more efficient electrical components. However, the introduction of a complex electrical network onboard mobile systems poses significant challenges for control design. A notable challenge is the coordination of multi-domain and multi-timescale system dynamics. This article seeks to address this challenge through the design and validation of a model predictive controller for a hybrid unmanned aerial vehicle powertrain. A multi-domain extension of the graph-based modeling framework is formulated and used to model the multi-physics behavior of the air vehicle. An extensive model validation procedure is performed and the validated graph model is used to develop two control strategies: one baseline and one predictive controller. To coordinate multi-timescale system dynamics, the predictive controller leverages a hierarchical control architecture to plan a battery state of charge bound. The control strategies are experimentally validated and show that the advanced controller yields improvements in performance and reliability metrics while reducing fuel consumption by ∼10%.

Experimental Analysis of Hybrid UAV at Different Velocities

The primary goal of this project is to constricting a hybrid UAV with both rotary and flapping wing. The primary objective of this project is to find the Lift in respect to RPM/Frequency in different modes of operation i.e. with operating only the propeller, flapping wing and with both propeller and flapping wing working simultaneously. For finding lift we will be using load cell. we will be studying the effect of a Flapping Wing when placed in Quadcopter and check whether the result have a positive effect or negative effects. The end result show's that there's a minute increase in lift when flapping wing is added to a quadcopter

A Hybrid Unmanned Arieal Vehicle With A Rover For Disaster Rescue Management Operation

The present invention proposed in this paper is a multi-role UAV with in-built Rover for Disaster Rescue Management (DRM) operation. As we know, Disaster Rescue operation are very complex, difficult and time consuming. The loss of human life during such operations after a disaster has been an area of concern for various organizations. In places with heavy rainfall and bad weather, DRM operation becomes an uphill task. The proposed invention is a hybrid UAV with an in-built Rover capable of image capturing with live feeds to the remote central station and thermal image capturing capability. The system is built such that, in case of heavy debris and landslide where Rover operation can’t be initiated at starting due to blockage of path for rover to move, the UAV is initiated and the Rover takes over when is clear path is visible. The device is equipped with GPS (Global Positioning System) with sends the location to the central system or remote command Centre whenever the image capturing system detects a heat signature through thermal imaging. In case of GPS failure, the system is developed with secondary back up which drops a sensors marker which the remote unit can track. The system proposed here is developed with an aim of reducing the loss of human life and increase effective DRM operation which reduces the time taken for search and rescue operation.

Multidisciplinary design optimization of an electric propulsion system of a hybrid UAV considering wind disturbance rejection capability in the quadrotor mode

The electric propulsion system (EPS) of a quadrotor fixed-wing hybrid unmanned aerial vehicle (QFHUAV) has important effects on its time of endurance and wind disturbance rejection capability in the quadrotor mode. Currently, the design methods of most QFHUAV EPSs are to design the quadrotor propulsion system and fixed-wing propulsion system independently. The wind disturbance rejection capability in the quadrotor mode is not considered in these methods. The multidisciplinary design optimization (MDO) method can reduce design time and cost by integrating all the disciplines involved in the design process. The MDO solutions are generally more optimal with respect to standard optimal sequential solutions. This paper proposes an MDO for a QFHUAV EPS considering the wind disturbance rejection capability in the quadrotor mode. The analysis modules of the propeller/rotor discipline, brushless direct current motor discipline, electronic speed control discipline, lithium polymer battery discipline, time of endurance discipline, mass discipline, and wind disturbance rejection capability in the quadrotor mode discipline are modeled. The MDO process of a QFHUAV EPS is constructed according to the transfer process and coupling relations among the discipline parameters. Based on the mission profile, the flight performance and mission requirements of the QFHUAV are created and a multi-objective optimization design model of the QFHUAV EPS is modeled. The Multidisciplinary feasible approach is implemented to decompose the mass coupling variables between the EPS component analysis modules and the mass analysis module effectively. A multi-objective evolutionary algorithm named NSGA-II is used to discover the full Pareto front for the multi-objective problem. The proposed MDO method is used to design the EPS of a self-developed QFHUAV. The optimal combination of QFHUAV EPS components is determined based on the optimization results. A comparison between the optimization results and the actual flight performance of the QFHUAV shows that the flight performance is in good agreement with the optimization results, which indicates that the MDO method proposed in this paper is feasible and reasonable.

TWQH Attitude Control Experiments on Horizon Ground Simulator and Flight Test

This paper presents the results of two experiments on the Horizon ground simulator and outdoor flight test of TWQH hybrid UAV in presence of wind perturbation. The simulation results show the stability and error boundedness of the PID controller while the experimental inflight tests indicate the good performances of the proposed controller.

基于复合式无人机的输电通道监测与图像分类

基于复合式无人机的输电通道监测与图像分类

Energy-Optimal Guidance of Hybrid Ultra-Long Endurance UAV

The paper addresses the problem of calculating energy optimal trajectory for a novel class of hybrid UAV equipped with hydrogen fuel cell and solar photovoltaic energy production technologies. The objective of the design is to minimize the energy used for propulsion by optimally utilizing the finite energy stored in the onboard hydrogen fuel cell and routing the aircraft through the time-varying energy fields of solar irradiance and wind. The optimal guidance task is formulated as a two-point boundary value problem with an objective of finding the minimum energy route and the associated controls. The task is solved by applying Pontryagin minimum principle to the resulting 2D kinematics of a UAV along with its aerodynamics, energy management, and propulsion models. The paper derives the necessary conditions and synthesizes the optimal control laws of the bank angle and the airspeed which depend on the time and position derivatives of the wind, and the total angle of incidence toward the sun. The developed method is used to solve a task of path planning of a long endurance flight of a hybrid UAV over multiple 1000 nmi.

Design and Implementation of Hybrid UAV Starter/Generator Module

UAVs have the advantages of long endurance, remote operation, high load capacity, high reliability, etc. Its airborne energy power system is the key core technology of the aircraft platform. Based on the research on the electrical power supply system of UAVs, a starter/generator module for the hybrid power system is designed in this paper. This module has functions such as engine electric starter, power generation, secondary power supply, uninterrupted circuit, status monitoring, fault detection and so on. Through the modeling and simulation of permanent magnet brushless DC motor system and the hardware and software circuit design based on TMS320F28035 control chip, the Principle Prototype of starter/generator module was developed. The experimental results show that the module can work normally and achieve its function. That means hybrid UAV starter/generator module has good performances.

Conceptual design method adapted to electric/hybrid aircraft developments

Developing more electric, hybrid, and full electric aircraft became one of the most important research directions today. The available and emerging technologies, mainly due to the low specific energy of batteries, have not yet allowed the development of full electric aircraft with performance similar to existing conventional ones. This paper deals with the adaptation of conceptual design methodologies to electric/hybrid aircraft development. It introduces the analysis of energy fractions of flight mission stages into the conceptual design, the definition of extra constraints for optimisation, and the implementation of the hybridisation factor and power split. The applicability of the adapted method is demonstrated through the development case studies of a full electric small aircraft and a cargo hybrid UAV.

A method for evaluating the wind disturbance rejection capability of a hybrid UAV in the quadrotor mode

The wind disturbance rejection capability of a quadrotor fixed-wing hybrid unmanned aerial vehicle (QFHUAV) in the quadrotor mode is an important factor restricting its large-scale applications. In this paper, based on static equilibrium analysis of the quadrotor mode of a QFHUAV with a wind disturbance, a method for analyzing and evaluating the wind disturbance rejection capability of the QFHUAV in the quadrotor mode is presented. The six degrees-of-freedom (6-DOF) static equilibrium equations of the QFHUAV are established in headwind and crosswind situations. The maximum wind velocity that satisfies the equilibrium equations under the constraints of the maximum thrust and torque of the quadrotor propulsion system is used to determine the wind disturbance rejection capability of the QFHUAV in the quadrotor mode. A QFHUAV with a twin-boom is used as an example to analyze and evaluate its wind disturbance rejection capability in the quadrotor mode. The configuration parameters, quadrotor propulsion system parameters, and aerodynamic parameters affecting the wind disturbance rejection capability of the QFHUAV in the quadrotor mode are presented, discussed, and explained. The yawing moment from the wind disturbance is the main factor threatening the safe flight of the QFHUAV in the quadrotor mode. The rotor disk angle, the maximum thrust of the quadrotor propulsion system, and the moment arms of the components of the quadrotor propulsion system thrust are the main factors affecting the wind disturbance rejection capability of the QFHUAV in the quadrotor mode. Increasing these parameter values is an effective approach to improve the wind disturbance rejection capability of the QFHUAV in the quadrotor mode. From the perspective of wind disturbance rejection capability, tailless and X-type layouts are better choices for QFHUAVs. The correctness of results obtained by the proposed method is verified by two flight test schemes.