A novel method for estimating the space range of battery-powered vertical take-off and landing(VTOL) aircraft is presented. The method is based on flight parameter optimization and numerical iteration. Subsystem model...A novel method for estimating the space range of battery-powered vertical take-off and landing(VTOL) aircraft is presented. The method is based on flight parameter optimization and numerical iteration. Subsystem models including required thrust, required power and battery discharge models are presented. The problem to be optimized is formulated, and then case study simulation is conducted using the established method for quantitative analysis. Simulation results show that the space range of battery-powered VTOL aircraft in a vertical plane is an oblate curve, which appears horizontally long but vertically short, and the peak point is not located on the vertical climb path. The method and results are confirmed by parameter analysis and validations.展开更多
The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wi...The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wing tips.The latter forces are not perpendicular to the body axis of the drone but are tilted by a small angle.The dynamic model of the VTOL undergoes ap-proximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method.For the approximately linearized model,an H-infinity feedback controller is designed.The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the VTOL aircraft.The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the aerial drone,under model uncertainties and external per-turbations.For the computation of the contollr's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the VTOL aircnaft,under moderate variations of the control inputs.The stability properties of the control scheme are proven through Lyapunov analysis.展开更多
This paper presents a new stabilizing control law for a planar vertical take-off and landing aircraft.The model is first transformed into an equivalent form,and then a control law consisting of a linear term and a sat...This paper presents a new stabilizing control law for a planar vertical take-off and landing aircraft.The model is first transformed into an equivalent form,and then a control law consisting of a linear term and a saturated term is given for a related subsystem,with the saturation levels being assigned as large as possible.Compared to the existing saturation scheme in which all states are restricted by saturations,the design brings about a relatively fast convergence.The effectiveness and advantage of the design are validated by numerical simulations.展开更多
Battery powered vertical takeoff and landing(VTOL) aircraft attracts more and more interests from public, while limited hover endurance hinders many prospective applications. Based on the weight models of battery, mot...Battery powered vertical takeoff and landing(VTOL) aircraft attracts more and more interests from public, while limited hover endurance hinders many prospective applications. Based on the weight models of battery, motor and electronic speed controller, the power consumption model of propeller and the constant power discharge model of battery, an efficient method to estimate the hover endurance of battery powered VTOL aircraft was presented. In order to understand the mechanism of performance improvement, the impacts of propulsion system parameters on hover endurance were analyzed by simulations, including the motor power density, the battery capacity, specific energy and Peukert coefficient. Ground experiment platform was established and validation experiments were carried out, the results of which showed a well agreement with the simulations. The estimation method and the analysis results could be used for optimization design and hover performance evaluation of battery powered VTOL aircraft.展开更多
Nowadays, the success of the new technology development and deployment process depends not only on technical, technological solutions, but also on solving the non-technological problems and crossing the societal and p...Nowadays, the success of the new technology development and deployment process depends not only on technical, technological solutions, but also on solving the non-technological problems and crossing the societal and psychological barriers. A large international European projects, GABRIEL1 had developed a maglev assisted aircraft take-off and landing, that was applied to conceptual design of aircraft and required on-board and ground systems, had analysed all impacts (effects of concept deployment on effectiveness, safety, security, noise, emissions) and had demonstrated the safe applicability by concept validation. The applied methodology, used methods and the results of the Gabriel projects had been described and discussed by 55 project deliverables. This paper has a special goal: investigating the problems and barriers of possible implementing of the radically new technology, aircraft MagLev assisted take-off and landing. The study was started by identification and classification of the problems and barriers. After it, the problems were systematically analysed by use of special methodology containing the understanding (description) of the problems, investigation of the possible solutions and discussing their applicability (mainly by use of the Gabriel project results). The paper has three major sections: 1) description of the Gabriel concept and project results, 2) introducing some related thoughts on general aspects of new technology developments, and 3) discussion on the problems and their solutions. The major classes of the problems are the 1) technical, technological problems as developing a radically new solution, landing the undercarriage-less aircraft on the magnetic tracks, 2) stakeholders’ problems as decision makers kicking against supporting the developments of so radically new technologies and 3) society barriers like society worrying on and fear of future passengers on flying by aircraft have not conventional undercarriage systems. The paper will show that these problems have safe and cost-effective solutions.展开更多
Climate change (CC) and variability have been world widely reported to pose number of risks in aviation industry including accidents, astray, and other operational difficulties. The impact of weather on landing and ta...Climate change (CC) and variability have been world widely reported to pose number of risks in aviation industry including accidents, astray, and other operational difficulties. The impact of weather on landing and take-off performances has been several times experienced at Abeid Amani Karume International Airport (AAKIA);however, the influence of climate change and variability to the aircraft performance needs to be assessed. Thus, this study investigated the influence of climate change and variability on aircrafts take-off and landing performances. Specifically, the study investigated;i) the influence of climate change on Take-off Distance Required (TODR) and Maximum Take-off Mass (MTOM) for different types of aircraft;ii) the influence of climate variability to the aircraft landing performance on light, medium and heavy aircraft and lastly, iii) the study investigated the seasonal and annual variability on aircraft landing performance due to climate variability. The datasets used in this study include the eight years (2014-2021), aircraft operational records (diversion and missed approach events) and Aviation Routine Weather Reports (METAR) records which were utilized as the indicators for landing performance, the long-term (1990-2020) annual maximum temperatures (Tmax) which was used to determine the TODR and MTOM. Statistical tools including mean, percentage changes, correlations, regression, and the chi-square test were used for analysis and hypotheses testing. The results revealed that light and medium aircraft categories were significantly most affected on diversion events as compared to the heavy categories;however, for the missed approach events the impact was vice versa. Moreover, the seasonal and annual variability on diversion and missed approach events were significantly different (at p ≤ 0.001). As for the take-off performance, results show that the TODR and MTOM were significantly increasing and decreasing (at p ≤ 0.001), based on increasing air temperatures. Therefore, the study concludes that the changing climate has significantly affected aircraft by increasing the TODR and decreasing the MTOM, while the climate variability has significantly affected landing performance by influencing the diversion and missed approach events. Thus, the study recommends (i) further research works including the feasibility study on runway extension for the safety of future aircraft operations at the AAKIA and (ii) proper maintenance and improvement of the Instrumental Landing Systems (ILS) as an adaptation measures to the landing aircraft during bad weather events.展开更多
The health management of batteries is a key enabler for the adoption of Electric Vertical Take-off and Landingvehicles (eVTOLs). Currently, few studies consider the health management of eVTOL batteries. One distinctch...The health management of batteries is a key enabler for the adoption of Electric Vertical Take-off and Landingvehicles (eVTOLs). Currently, few studies consider the health management of eVTOL batteries. One distinctcharacteristic of batteries for eVTOLs is that the discharge rates are significantly larger during take-off andlanding, compared with the battery discharge rates needed for automotives. Such discharge protocols areexpected to impact the long-run health of batteries. This paper proposes a data-driven machine learningframework to estimate the state-of-health and remaining-useful-lifetime of eVTOL batteries under varying flightconditions and taking into account the entire flight profile of the eVTOLs. Three main features are consideredfor the assessment of the health of the batteries: charge, discharge and temperature. The importance of thesefeatures is also quantified. Considering battery charging before flight, a selection of missions for state-ofhealth and remaining-useful-lifetime prediction is performed. The results show that indeed, discharge-relatedfeatures have the highest importance when predicting battery state-of-health and remaining-useful-lifetime.Using several machine learning algorithms, it is shown that the battery state-of-health and remaining-useful-lifeare well estimated using Random Forest regression and Extreme Gradient Boosting, respectively.展开更多
In this paper.Active Disturbance Rejection Control(ADRC)is utilized in the pitch control of a vertical take-off and landing fixed-wing Unmanned Aerial Vehicle(UAV)to address the problem of height fluctuation during th...In this paper.Active Disturbance Rejection Control(ADRC)is utilized in the pitch control of a vertical take-off and landing fixed-wing Unmanned Aerial Vehicle(UAV)to address the problem of height fluctuation during the transition from hover to level flight.Considering the difficulty of parameter tuning of ADRC as well as the requirement of accuracy and rapidity of the controller,a Multi-Strategy Pigeon-Inspired Optimization(MSPIO)algorithm is employed.Particle Swarm Optimization(PSO),Genetic Algorithm(GA),the basic Pigeon-Inspired Optimization(PIO),and an improved PIO algorithm CMPIO are compared.In addition,the optimized ADRC control system is compared with the pure Proportional-Integral-Derivative(PID)control system and the non-optimized ADRC control system.The effectiveness of the designed control strategy for forward transition is verified and the faster convergence speed and better exploitation ability of the proposed MSPIO algorithm are confirmed by simulation results.展开更多
根据旋翼机和固定翼飞机的气动理论开发了一个综合方法过程用于估算电动垂直起降(Electric vertical takeoff and landing, e VTOL)飞行器的飞行性能。这种飞机通常采用多旋翼垂直飞行,螺旋桨和机翼的不同组合方式实现飞行。其中,对旋...根据旋翼机和固定翼飞机的气动理论开发了一个综合方法过程用于估算电动垂直起降(Electric vertical takeoff and landing, e VTOL)飞行器的飞行性能。这种飞机通常采用多旋翼垂直飞行,螺旋桨和机翼的不同组合方式实现飞行。其中,对旋翼和螺旋桨的气动性能采用传统动量理论分析和旋翼元素分析。本文利用此综合理论研究了12架e VTOL飞行器的飞行性能,包括多旋翼飞行器、矢量推进飞行器和升力巡航飞行器。计算了悬停、爬升和下降以及巡航水平飞行,不同飞行状态时驱动电机、旋翼和机身的飞行特性。据此,可以进一步确定电力推进系统的性能指标,以匹配螺旋桨或旋翼,从而满足飞行任务。展开更多
Modern day VTOL fixed-wing aircraft based on quadplane design is relative<span style="font-family:Verdana;">ly simple and reliable due to lack of complex mechanical components</span><span styl...Modern day VTOL fixed-wing aircraft based on quadplane design is relative<span style="font-family:Verdana;">ly simple and reliable due to lack of complex mechanical components</span><span style="font-family:Verdana;"> com</span><span style="font-family:Verdana;">pared to tilt-wings or tilt-rotors in the pre-80’s era. Radio-controlled </span><span style="font-family:Verdana;">aerobatic airplanes have thrust-to-weight ratio of greater than unity and are capable of performing a range of impressive maneuvers including the so-called harrier maneuver. We hereby present a new maneuver known as the retarded harrier </span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">that is applicable to un/manned fixed-wing aircraft for achieving VTOL flight with a better forward flight performance than a quadplane in terms of weight, speed and esthetics.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> An airplane with tandem roto-stabilizers is also presented as an efficient airframe to achieve VTOL via retarded harrier maneuver, and detailed analysis is given for hovering at 45° and 60° and comparison is made against the widely adopted quadplane. This work also includes experimental demonstration of retarded harrier maneuver using a small remotely pilot airplane of wingspan 650 mm.</span></span></span>展开更多
Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in ...Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in the proposed article. During the computer simulation process, kinematics parameters diagrams were made, aerodynamic coefficients and propellers thrust components at all stages of aircraft take-off were estimated. That numerical data can be used in a preliminary stage of aerodynamic design for the vertical take-off and landing aircraft and electric drones at the determination of control and equalization elements geometric and kinematic parameters.展开更多
文摘A novel method for estimating the space range of battery-powered vertical take-off and landing(VTOL) aircraft is presented. The method is based on flight parameter optimization and numerical iteration. Subsystem models including required thrust, required power and battery discharge models are presented. The problem to be optimized is formulated, and then case study simulation is conducted using the established method for quantitative analysis. Simulation results show that the space range of battery-powered VTOL aircraft in a vertical plane is an oblate curve, which appears horizontally long but vertically short, and the peak point is not located on the vertical climb path. The method and results are confirmed by parameter analysis and validations.
文摘The paper proposes a nonlinear optimal control approach for the model of the vertical take off and landing(VTOL)aircraft.This aerial drone receives as control input a directed thrust,as well as forces acting on its wing tips.The latter forces are not perpendicular to the body axis of the drone but are tilted by a small angle.The dynamic model of the VTOL undergoes ap-proximate linearization with the use of Taylor series expansion around a temporary operating point which is recomputed at each iteration of the control method.For the approximately linearized model,an H-infinity feedback controller is designed.The linearization procedure relies on the computation of the Jacobian matrices of the state-space model of the VTOL aircraft.The proposed control method stands for the solution of the optimal control problem for the nonlinear and multivariable dynamics of the aerial drone,under model uncertainties and external per-turbations.For the computation of the contollr's feedback gains,an algebraic Riccati equation is solved at each time-step of the control method.The new nonlinear optimal control approach achieves fast and accurate tracking for all state variables of the VTOL aircnaft,under moderate variations of the control inputs.The stability properties of the control scheme are proven through Lyapunov analysis.
基金supported by the National Natural Science Foundation of China (No. 60874008)the Research Fund for the Doctoral Program of High Education of China (No. 200805331102)
文摘This paper presents a new stabilizing control law for a planar vertical take-off and landing aircraft.The model is first transformed into an equivalent form,and then a control law consisting of a linear term and a saturated term is given for a related subsystem,with the saturation levels being assigned as large as possible.Compared to the existing saturation scheme in which all states are restricted by saturations,the design brings about a relatively fast convergence.The effectiveness and advantage of the design are validated by numerical simulations.
文摘Battery powered vertical takeoff and landing(VTOL) aircraft attracts more and more interests from public, while limited hover endurance hinders many prospective applications. Based on the weight models of battery, motor and electronic speed controller, the power consumption model of propeller and the constant power discharge model of battery, an efficient method to estimate the hover endurance of battery powered VTOL aircraft was presented. In order to understand the mechanism of performance improvement, the impacts of propulsion system parameters on hover endurance were analyzed by simulations, including the motor power density, the battery capacity, specific energy and Peukert coefficient. Ground experiment platform was established and validation experiments were carried out, the results of which showed a well agreement with the simulations. The estimation method and the analysis results could be used for optimization design and hover performance evaluation of battery powered VTOL aircraft.
文摘Nowadays, the success of the new technology development and deployment process depends not only on technical, technological solutions, but also on solving the non-technological problems and crossing the societal and psychological barriers. A large international European projects, GABRIEL1 had developed a maglev assisted aircraft take-off and landing, that was applied to conceptual design of aircraft and required on-board and ground systems, had analysed all impacts (effects of concept deployment on effectiveness, safety, security, noise, emissions) and had demonstrated the safe applicability by concept validation. The applied methodology, used methods and the results of the Gabriel projects had been described and discussed by 55 project deliverables. This paper has a special goal: investigating the problems and barriers of possible implementing of the radically new technology, aircraft MagLev assisted take-off and landing. The study was started by identification and classification of the problems and barriers. After it, the problems were systematically analysed by use of special methodology containing the understanding (description) of the problems, investigation of the possible solutions and discussing their applicability (mainly by use of the Gabriel project results). The paper has three major sections: 1) description of the Gabriel concept and project results, 2) introducing some related thoughts on general aspects of new technology developments, and 3) discussion on the problems and their solutions. The major classes of the problems are the 1) technical, technological problems as developing a radically new solution, landing the undercarriage-less aircraft on the magnetic tracks, 2) stakeholders’ problems as decision makers kicking against supporting the developments of so radically new technologies and 3) society barriers like society worrying on and fear of future passengers on flying by aircraft have not conventional undercarriage systems. The paper will show that these problems have safe and cost-effective solutions.
文摘Climate change (CC) and variability have been world widely reported to pose number of risks in aviation industry including accidents, astray, and other operational difficulties. The impact of weather on landing and take-off performances has been several times experienced at Abeid Amani Karume International Airport (AAKIA);however, the influence of climate change and variability to the aircraft performance needs to be assessed. Thus, this study investigated the influence of climate change and variability on aircrafts take-off and landing performances. Specifically, the study investigated;i) the influence of climate change on Take-off Distance Required (TODR) and Maximum Take-off Mass (MTOM) for different types of aircraft;ii) the influence of climate variability to the aircraft landing performance on light, medium and heavy aircraft and lastly, iii) the study investigated the seasonal and annual variability on aircraft landing performance due to climate variability. The datasets used in this study include the eight years (2014-2021), aircraft operational records (diversion and missed approach events) and Aviation Routine Weather Reports (METAR) records which were utilized as the indicators for landing performance, the long-term (1990-2020) annual maximum temperatures (Tmax) which was used to determine the TODR and MTOM. Statistical tools including mean, percentage changes, correlations, regression, and the chi-square test were used for analysis and hypotheses testing. The results revealed that light and medium aircraft categories were significantly most affected on diversion events as compared to the heavy categories;however, for the missed approach events the impact was vice versa. Moreover, the seasonal and annual variability on diversion and missed approach events were significantly different (at p ≤ 0.001). As for the take-off performance, results show that the TODR and MTOM were significantly increasing and decreasing (at p ≤ 0.001), based on increasing air temperatures. Therefore, the study concludes that the changing climate has significantly affected aircraft by increasing the TODR and decreasing the MTOM, while the climate variability has significantly affected landing performance by influencing the diversion and missed approach events. Thus, the study recommends (i) further research works including the feasibility study on runway extension for the safety of future aircraft operations at the AAKIA and (ii) proper maintenance and improvement of the Instrumental Landing Systems (ILS) as an adaptation measures to the landing aircraft during bad weather events.
文摘The health management of batteries is a key enabler for the adoption of Electric Vertical Take-off and Landingvehicles (eVTOLs). Currently, few studies consider the health management of eVTOL batteries. One distinctcharacteristic of batteries for eVTOLs is that the discharge rates are significantly larger during take-off andlanding, compared with the battery discharge rates needed for automotives. Such discharge protocols areexpected to impact the long-run health of batteries. This paper proposes a data-driven machine learningframework to estimate the state-of-health and remaining-useful-lifetime of eVTOL batteries under varying flightconditions and taking into account the entire flight profile of the eVTOLs. Three main features are consideredfor the assessment of the health of the batteries: charge, discharge and temperature. The importance of thesefeatures is also quantified. Considering battery charging before flight, a selection of missions for state-ofhealth and remaining-useful-lifetime prediction is performed. The results show that indeed, discharge-relatedfeatures have the highest importance when predicting battery state-of-health and remaining-useful-lifetime.Using several machine learning algorithms, it is shown that the battery state-of-health and remaining-useful-lifeare well estimated using Random Forest regression and Extreme Gradient Boosting, respectively.
基金supported by Science and Technology Innovation 2030-Key Project of"New Generation Artificial Intelli-gence",China(No.2018AAA0100803)National Natural Science Foundation of China(Nos.U20B2071,91948204,U1913602)Aeronautical Foundation of China(No.20185851022).
文摘In this paper.Active Disturbance Rejection Control(ADRC)is utilized in the pitch control of a vertical take-off and landing fixed-wing Unmanned Aerial Vehicle(UAV)to address the problem of height fluctuation during the transition from hover to level flight.Considering the difficulty of parameter tuning of ADRC as well as the requirement of accuracy and rapidity of the controller,a Multi-Strategy Pigeon-Inspired Optimization(MSPIO)algorithm is employed.Particle Swarm Optimization(PSO),Genetic Algorithm(GA),the basic Pigeon-Inspired Optimization(PIO),and an improved PIO algorithm CMPIO are compared.In addition,the optimized ADRC control system is compared with the pure Proportional-Integral-Derivative(PID)control system and the non-optimized ADRC control system.The effectiveness of the designed control strategy for forward transition is verified and the faster convergence speed and better exploitation ability of the proposed MSPIO algorithm are confirmed by simulation results.
文摘根据旋翼机和固定翼飞机的气动理论开发了一个综合方法过程用于估算电动垂直起降(Electric vertical takeoff and landing, e VTOL)飞行器的飞行性能。这种飞机通常采用多旋翼垂直飞行,螺旋桨和机翼的不同组合方式实现飞行。其中,对旋翼和螺旋桨的气动性能采用传统动量理论分析和旋翼元素分析。本文利用此综合理论研究了12架e VTOL飞行器的飞行性能,包括多旋翼飞行器、矢量推进飞行器和升力巡航飞行器。计算了悬停、爬升和下降以及巡航水平飞行,不同飞行状态时驱动电机、旋翼和机身的飞行特性。据此,可以进一步确定电力推进系统的性能指标,以匹配螺旋桨或旋翼,从而满足飞行任务。
文摘Modern day VTOL fixed-wing aircraft based on quadplane design is relative<span style="font-family:Verdana;">ly simple and reliable due to lack of complex mechanical components</span><span style="font-family:Verdana;"> com</span><span style="font-family:Verdana;">pared to tilt-wings or tilt-rotors in the pre-80’s era. Radio-controlled </span><span style="font-family:Verdana;">aerobatic airplanes have thrust-to-weight ratio of greater than unity and are capable of performing a range of impressive maneuvers including the so-called harrier maneuver. We hereby present a new maneuver known as the retarded harrier </span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">that is applicable to un/manned fixed-wing aircraft for achieving VTOL flight with a better forward flight performance than a quadplane in terms of weight, speed and esthetics.</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> An airplane with tandem roto-stabilizers is also presented as an efficient airframe to achieve VTOL via retarded harrier maneuver, and detailed analysis is given for hovering at 45° and 60° and comparison is made against the widely adopted quadplane. This work also includes experimental demonstration of retarded harrier maneuver using a small remotely pilot airplane of wingspan 650 mm.</span></span></span>
文摘Methodological issues associated with the determination of the vertical take-off and landing aerodynamic parameters equipped with two rotary propellers during take-off and hovering, descent and landing are studied in the proposed article. During the computer simulation process, kinematics parameters diagrams were made, aerodynamic coefficients and propellers thrust components at all stages of aircraft take-off were estimated. That numerical data can be used in a preliminary stage of aerodynamic design for the vertical take-off and landing aircraft and electric drones at the determination of control and equalization elements geometric and kinematic parameters.