Problems and Barriers Impeding the Implementation of MagLev Assisted Aircraft Take-Off and Landing Concept

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.

The Influence of Climate Change and Variability on Aircraft Take-off and Landing Performance;a Case Study of the Abeid Amani Karume International Airport-Zanzibar

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.

Selection of a non-localized landing region for an unmanned helicopter based on an attention model

A new landing region selection algorithm for an unmanned helicopter is proposed based on an attention model.Different from the original attention model,some properties of the possible safe landing regions（e.g.,depth,regional color and motion features）are included in the selection algorithm.Furthermore,regional color and motion features are fused directly into the saliency map because these features do not have the ＂central-peripheral＂property.Experimental results validate the feasibility and efficiency of this approach.

发酵农林废弃物对镉污染耕地安全利用效果及持效性研究

为探讨以针叶类树皮为主的农林废弃物发酵后对镉污染耕地大米中镉含量的影响,通过耕地修复实验室小试、盆栽及大田试验,系统研究FBA(修复材料)对耕地镉污染土壤的钝化效果,考察修复材料对作物生长情况、农作物产量、作物中镉吸收、土壤中镉有效态含量和土壤中其他理化指标的影响。研究表明:①FBA对水溶液中镉的去除率均在93.3%以上;②添加1%FBA能够促进了农作物分蘖发生;③添加1%FBA土壤中全氮增加30.85%,有机质增加26.61%,有效提高了土壤的肥力;④添加1%FBA的处理组当季稻米中的镉含量均低于0.2 mg/kg。通过研究结果可知,FBA无生物毒性,对种子发芽率、根伸长均有促进作用,不仅能够有效降低稻米中的镉含量,添加材料后的当季水稻镉含量即刻达标,同时修复效果保持稳定,而且具有一定的肥效作用。

不同叶面阻控剂对水稻生长和安全利用的影响

为探索水稻生产适用的高效、可推广的叶面阻控剂,本研究选用4种叶面阻控剂(黄腐酸钾、硅肥、锌肥和硒肥),探究其对水稻生长及产量的影响,以及对镉在水稻各器官中的富集和转运的影响。结果表明,在水稻分蘖期和灌浆期分别喷施4种叶面阻控剂后,水稻株高、分蘖数和千粒重均有不同程度增加,与空白对照相比,叶面阻控剂处理的水稻产量较空白处理增产0.34%~4.83%。叶面阻控剂施用后,水稻根部、茎部、叶部和籽粒中的镉含量均有所下降,所有处理籽粒中镉含量均符合食品安全标准。综合水稻产量与降镉效果,建议在轻度镉污染稻田采取叶面喷施硅肥技术措施阻控水稻镉吸收和转运,以实现水稻安全生产。

Prognostics for Lithium-ion batteries for electric Vertical Take-off andLanding aircraft using data-driven machine learning

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.

关于“净土收储”“净土供应”“净土开发”模式研究

为防范人居环境风险,确保土地开发利用符合土壤环境质量要求,各地结合实际实施建设用地准入管理和联动监管。在全面梳理各地准入管理相关做法的基础上,基于土地开发利用流程和土壤环境质量监管程序,对常见的“净土收储”“净土供应”“净土开发”三种模式进行了探讨,明晰各模式的内涵,分析各模式的实践情况及其利弊,进而提出因地制宜选择适用模式、强化部门联动监管、扩展资金筹措方式等对策建议,为完善建设用地准入管理、保障建设用地安全利用提供借鉴。

A multi-strategy pigeon-inspired optimization approach to active disturbance rejection control parameters tuning for vertical take-off and landing fixed-wing UAV

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.

Development of a Bird-like Flapping-wing Aerial Vehicle with Autonomous Take-off and Landing Capabilities

The lack of autonomous take-off and landing capabilities of bird-like flapping-wing aerial vehicles(BFAVs)seriously restricts their further development and application.Thus,combined with the current research results on the autonomous take-off and landing technology of unmanned aerial vehicles,four types of technologies are studied,including jumping take-off and landing technology,taxiing take-off and landing technology,gliding take-off and landing technology,and vertical take-off and landing(VTOL)technology.Based on the analytic hierarchy process(AHP)-comprehensive evaluation method,a fuzzy comprehensive evaluation model for the autonomous take-off and landing scheme of a BFAV is established,and four schemes are evaluated concretely.The results show that under the existing technical conditions,the hybrid layout VTOL scheme is the best.Furthermore,the detailed design and development of the prototype of a BFAV with a four-rotor hybrid layout are carried out,and the vehicle performance is tested.The results prove that through the four-rotor hybrid layout design,the BFAV has good autonomous take-off and landing abilities.The power consumption analysis shows that for a fixed-point reconnaissance mission,when the mission radius is less than 3.38 km,the VTOL type exhibits longer mission duration than the hand-launched type.

六盘水市Cd污染耕地农艺调控措施研究

六盘水市耕地土壤存在重金属Cd污染问题。为了保障农产品质量安全和安全利用受污染耕地,本研究选取典型Cd污染耕地,采用品种调整、原位钝化、叶面调控与微生物修复4项农艺调控措施开展试验,对治理后土壤中Cd含量和玉米籽实中Cd含量进行测定并综合评价治理效果,筛选适宜六盘水市Cd污染耕地的治理技术模式。结果表明,各项措施实施后,耕地安全利用率均达标,其中原位钝化措施降低土壤中Cd含量效果最好,最大降幅约23.99%;叶面调控措施降低玉米籽实中Cd含量显著,最大降幅约40%。

浙西南镉高背景值耕地的水稻安全利用技术研究

我国土壤镉(Cd)污染区与水稻种植区在空间分布上基本吻合,水稻属于易积累Cd的作物之一。浙江省西南部分区域,由于母质原因,出现地质性重金属高背景值现象。本研究开展了中轻度Cd污染耕地安全利用的核心技术田间试验,包括低积累水稻品种筛选、钝化修复材料筛选、农艺调控措施三项技术。结果表明:采用水稻甬优1540+石灰100 kg/亩+全生育期淹水+有机肥1150 kg/亩的安全利用集成技术模式能最大限度地降低水稻籽粒中的Cd含量,可以作为该区域镉高背景值耕地的水稻安全利用技术集成模式并推广应用。

钝化剂对镉铅污染土壤修复效果研究

【目的】农田土壤重金属污染问题是农产品安全的隐患,以镉铅污染土壤为试验地,探究镉铅污染土壤上农产品安全利用的有效钝化措施,为镉铅污染土壤安全利用提供切实有效的方法。【方法】通过对镉铅污染土壤撒施碱性钝化剂石灰石粉,施用量为0.3 kg/m^(2),检测石灰石粉施用前后土壤pH值、重金属有效态,测定施用后采收的上海青茎叶的重金属含量,分析石灰石粉钝化措施效果。【结果】实施石灰石粉处理后,镉铅污染土壤的pH值升高0.2,有效镉含量降低0.04 mg/kg、有效铅含量降低1.38 mg/kg,产出的农产品可食用部位重金属含量均低于国家标准的污染限量值。【结论】0.3 kg/m^(2)石灰石粉钝化处理能够实现镉铅污染土壤的有效镉、有效铅钝化,处理后的土壤能够实现农产品安全生产。

New stabilization design for planar vertical take-off and landing aircrafts

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.

黄土高原坡耕地退耕还林(草)的生态经济效应研究

退耕还林(草)是改善黄土高原生态环境的重要措施。粮食安全问题作为实施退耕还林(草)的基础背景,成为黄土高原生态经济增长能否产生正效应的拐点。文章分析了黄土高原退耕还林(草)的生态经济效应,认为该区实施退耕还林(草)过程中存在生态与经济效益的不协调,不仅严重制约着当地的经济发展和社会进步,也给黄河中下游地区造成了一系列隐患。针对如何实施好退耕还林(草)这项工程,提出了从当地经济发展的目标和基本区情出发,实施退耕还林(草)工程中生态与经济效益协调化的运行策略。

广州市土地安全预警系统与RBF评估模型的构建

土地资源安全预警是区域资源安全研究的重点,通过构建具有实际操作意义的土地资源安全预警系统,可以进行土地资源安全的综合分析,以此来判断城市土地资源安全变化趋势。以广州市为例,应用人工神经网络改进模型(RBF)进行土地资源安全的综合评价,表明广州市土地资源安全已由轻警转为中警状态。实践证明RBF模型对土地资源安全综合评价具有较高的客观性和准确性。

惯导/测距/测速相结合的安全软着陆自主导航方法

针对地外天体软着陆中惯导误差随时间增大,无法提供准确的高度和三维速度信息的问题,提出了一种惯导、测距和测速相结合的安全软着陆导航方法。该方法以惯导为基础,利用测距仪修正惯导的高度信息,利用测速敏感器修正惯导的速度信息。详细介绍了惯性导航的基本原理及测距、测速组合修正的策略,对软着陆过程的动力学模型、敏感器测量模型、滤波方程、地形对修正的影响,以及组合使用的策略和算法等问题进行了论述。数学仿真结果表明惯导、测距和测速相结合的方法能够满足安全软着陆的需要。

中国粮食自给率与耕地资源安全底线的探讨

首先就粮食属性、粮食饥馑、粮食禁运、粮食贸易等与粮食安全密切相关的问题进行了深刻反思,并通过对国际国内粮食消费、粮食生产和粮食贸易的发展态势分析,探讨了中国适度粮食自给率的问题,由此提出当前中国粮食自给率目标以90%左右为宜。在此基础上,通过估算预期粮食综合生产能力,以人均粮食需求量420kg,粮食自给率达到90%为情景,确定我国近期适宜的耕地资源安全底线是人均0.056hm2。同时指出不同地区的人均粮食消费量不同,粮食自给率也会有区别,所以各地需要制定区域性或省级的耕地资源安全底线标准。

河南省粮食安全保障研究

利用GIS技术和作物生长机理模型对河南省的粮食生产潜力进行了测算 ,并在对粮食需求量分析的基础上 ,得出通过保护耕地数量和提高土地生产力 ,河南省不仅可以解决自身的粮食安全保障问题 。

一种基于形态学的探测器安全着陆点选择方法

探测器着陆点选择的优劣直接关系到探测器能否安全降落。提出了一种基于数学形态学的探测器安全着陆点选择算法。该算法先利用灰度形态学中的高、低帽变换对探测目标表面的弹坑及岩石等障碍进行检测,然后对形成的多连通区域利用数学形态学进行骨架提取并修正,进而求出最佳安全着陆点以及安全着陆半径,最后通过仿真验证了该算法的有效性。

月球探测器着陆中基于被动图像的着陆场搜索及斜坡估计

在无人探测器月面软着陆技术研究中,因为月球表面障碍物对探测器着陆安全构成的威胁,所以首先需要解决的是安全着陆区域确定及其坡度估计的问题。从被动图像角度出发,研究了基于灰度变化的着陆区域确定和基于两视图几何的候选着陆区域坡度估计的方法。首先,研究了一种基于多尺度窗口区域内灰度变化标准差的安全着陆候选区域确定方法;其次,为了计算基础矩阵F和单应矩阵H,本文利用SIFT算法和RANSAC策略进行特征点检测和跟踪;最后,本文利用平面单应H和基础矩阵F的相容性原理,提出了一种斜坡坡度估计方法。和同类方法相比,该方法无需探测器位姿转移参数。利用该方法得到的斜坡估计结果和其他方法的结果比较后可知:本文提出的方法检测出的坡度误差能够满足着陆过程中斜坡检测的要求。