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
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
飞行控制系统作为电动垂直起降(electric vertical take-off and landing,eVTOL)飞行器的关键机载系统,需要具备和民机同样的安全性。为了设计满足eVTOL飞行器需求的飞控系统架构,根据适航规章梳理了安全性要求,并基于安全性要求介绍了e...飞行控制系统作为电动垂直起降(electric vertical take-off and landing,eVTOL)飞行器的关键机载系统,需要具备和民机同样的安全性。为了设计满足eVTOL飞行器需求的飞控系统架构,根据适航规章梳理了安全性要求,并基于安全性要求介绍了eVTOL飞行器飞控系统飞控计算机、传感器和作动器余度设计技术,设计了一种基于安全性考虑的eVTOL飞行器飞控系统架构;分析了eVTOL飞行器旋翼构型下的典型功能危险,并采用故障树进行了安全性分析。结果表明,设计的飞控系统架构的典型功能危险能够满足失效概率的要求。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
Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propul...Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.展开更多
为迎接电动垂直起降航空器的到来,降低平均无故障时间,对电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器的一般运行场景和系统构成做出了分析,并从人为因素、设备因素、环境因素和其他因素中提取了可能的失效诱因;...为迎接电动垂直起降航空器的到来,降低平均无故障时间,对电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器的一般运行场景和系统构成做出了分析,并从人为因素、设备因素、环境因素和其他因素中提取了可能的失效诱因;构建了失控坠地和空中碰撞的贝叶斯网络,并依据所建网络和通过不同专家得到的概率值计算控制失效情况下失控坠地和中间事件发生概率,然后进行反向推断,推演事故发生主要诱因。结果表明:电动垂直起降航空器正常运行发生事故的概率为9.648×10^(-7),其中,控制失效、飞控系统断电/故障是事故主要诱因,计算结果可为电动垂直起降航空器安全运行防控提供依据。展开更多
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.
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.
文摘飞行控制系统作为电动垂直起降(electric vertical take-off and landing,eVTOL)飞行器的关键机载系统,需要具备和民机同样的安全性。为了设计满足eVTOL飞行器需求的飞控系统架构,根据适航规章梳理了安全性要求,并基于安全性要求介绍了eVTOL飞行器飞控系统飞控计算机、传感器和作动器余度设计技术,设计了一种基于安全性考虑的eVTOL飞行器飞控系统架构;分析了eVTOL飞行器旋翼构型下的典型功能危险,并采用故障树进行了安全性分析。结果表明,设计的飞控系统架构的典型功能危险能够满足失效概率的要求。
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。
基金supported by the National Natural Science Foundation of China(No.51877178)。
文摘Distributed Electric Propulsion(DEP)aircraft use multiple electric motors to drive the propulsors,which gives potential benefits to aerodynamic-propulsion interaction.To investigate and quantify the aerodynamic-propulsion interaction effect of the wing section,we built a DEP demonstrator with 24"high-lift"Electric Ducted Fans(EDFs)distributed along the wing’s trailing edge.This paper explores and compares the aero-propulsion coupling characteristics under various upstream speed,throttle,and EDF mounting surface deflection angles using a series of wind tunnel tests.We compare various lift-augmentation power conditions to the clean configuration without propulsion unit under the experiment condition of 15-25 m/s freestream flow and angles of attack from-4°to 16°.The comparison of computational results to the experimental results verifies the effectiveness of the computational fluid dynamic analysis method and the modeling method for the DEP configuration.The results show that the EDFs can produce significant lift increment and drag reduction simultaneously,which is accordant with the potential benefit of Boundary Layer Ingestion(BLI)at low airspeed.
文摘为迎接电动垂直起降航空器的到来,降低平均无故障时间,对电动垂直起降(electric vertical takeoff and landing,eVTOL)航空器的一般运行场景和系统构成做出了分析,并从人为因素、设备因素、环境因素和其他因素中提取了可能的失效诱因;构建了失控坠地和空中碰撞的贝叶斯网络,并依据所建网络和通过不同专家得到的概率值计算控制失效情况下失控坠地和中间事件发生概率,然后进行反向推断,推演事故发生主要诱因。结果表明:电动垂直起降航空器正常运行发生事故的概率为9.648×10^(-7),其中,控制失效、飞控系统断电/故障是事故主要诱因,计算结果可为电动垂直起降航空器安全运行防控提供依据。
