共查询到16条相似文献,搜索用时 342 毫秒
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飞机地面操纵转弯半径和转弯速度计算方法研究 总被引:1,自引:0,他引:1
对于具有前轮操纵系统的飞机 ,本文给出了飞机地面操纵转弯半径和转弯速度的计算方法 ,并分析了飞机地面操纵转弯半径与转弯速度之间的关系 相似文献
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飞机在进行地面转弯过程中,机场道面不平、侧风等环境因素可能导致主起落架转向轮的实际转角与理论转角不符,引起前轮转角和两侧主轮转角关系不匹配,增大轮胎侧向力,主起落架受到的扭矩增加。针对上述问题,提出两侧主轮独立控制的飞机地面转弯控制策略和基于内侧主起落架转向轮为主导对象,外侧主起落架转向轮为从动对象的主从控制策略以及实时转弯角度控制算法。建立基于弹性轮胎的飞机地面转弯模型,计算飞机地面转弯时的主起落架总扭矩。通过MATLAB设置不同主轮转角偏差,对两侧主轮的独立控制策略和主从控制策略下的主起落架总扭矩进行对比,发现前者能更有效降低飞机主起落架扭矩,增加飞机地面转弯安全性以及减小起落架设计难度。 相似文献
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串列多支柱主起落架布局飞机的起飞载荷研究 总被引:1,自引:0,他引:1
大型军用运输机、民航客机广泛采用可视为前三点式(前起落架组、左主起落架组、右主起落架组)的多支柱起落架布局方案.通常,此类飞机的最大起飞质量高达数百吨,起飞滑跑速度也较大,因此,起飞情况是起落架强度设计的重点.本文基于前三点式起落架计算理论,以及对An-124、An-225飞机起落架设计方案的研究,提出一类串列多支柱多轮主起落架的起飞情况地面载荷算法. 相似文献
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飞机地面转弯和刹车响应动力学分析 总被引:5,自引:2,他引:3
建立了飞机地面运动的数学模型,模型中考虑机体的六自由度运动和起落架弹性;基于滑移率控制方式建立了机轮防滑刹车模型。通过仿真得出了飞机地面匀速转弯和滑跑刹车的动态响应。其结果表明,飞机匀速转弯时,其峰值出现在初始非稳态时刻;弹性起落架在着陆和刹车过程中产生走步现象;采用滑移率控制方式使飞机在整个刹车过程中取得最佳刹车性能。 相似文献
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推导了某型飞机尾起落架主支柱转角与缓冲器行程的关系,以及尾起落架主支柱转角与轮轴倾角之间的关系,并指出在停机载荷下,尾起落架轮轴倾角受到主支柱转角的影响。将某型飞机与它同类型飞机尾起落架的转弯情况进行了比较,发现某型飞机尾起落架转弯困难的原因是:在停机载荷下,缓冲器压缩量较大,轮叉转动较小的角度就可以导致轮轴与地面之间产生较大的倾角。在满足缓冲性能的基础上,将某型飞机的尾起落架缓冲器重新进行了充填,提高其充气压力,减少灌油量,使尾起落架缓冲器在停机载荷下的压缩量为0。缓冲器经过重新充填后,在停机载荷下,该型飞机尾起落架轮轴与地面的倾角始终为0°,机轮垂直地面,即使在小转弯半径条件下,牵引转弯和首飞滑跑转弯时,尾起落架机轮左右转动也很灵活。改变该飞机尾起落架缓冲器充填参数后,解决了转弯困难的问题。 相似文献
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为了使运输类飞机起落架的设计更好地满足适航规范的要求,介绍一种针对CCAR25部规范要求的计算起落架地面操纵载荷的流程,并提出根据轮胎、缓冲支柱压缩状态计算起落架基本尺寸数据和飞机姿态的旋转"虚拟接地点"方法。通过上述流程能够计算得到起落架地面操纵载荷结果,包括飞机在某种地面操纵工况下的姿态、地面坐标系和飞机坐标系下的地面操纵载荷以及起落架基本尺寸数据。通过对转弯地面载荷工况的计算与分析,表明计算流程和旋转"虚拟接地点"方法是准确可靠的且能较好地满足CCAR25部规范要求。 相似文献
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This study investigates an instability that was observed during high-speed taxi tests of an experimental flying-wing aircraft.In order to resolve the reason of instability and probable solution of it,the instability was reproduced in simulations.An analysis revealed the unique stability characteristics of this aircraft.This aircraft has a rigid connection between the nose wheel steering mechanism and an electric servo,which is different from aircraft with a conventional tricycle landing gear system.The analysis based on simulation results suggests that there are two reasons for the instability.The first reason is a reversal of the lateral velocity of the nose wheel.The second reason is that the moment about the center of gravity created by the lateral friction force from the nose wheel is larger than that from the lateral friction force from the main wheels.These problems were corrected by changing the ground pitch angle.Simulations show that reducing the ground pitch angle can eliminate the instability in high-speed taxi. 相似文献
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《中国航空学报》2021,34(10):166-176
The maneuvering time on the ground accounts for 10%–30% of their flight time, and it always exceeds 50% for short-haul aircraft when the ground traffic is congested. Aircraft also contribute significantly to emissions, fuel burn, and noise when taxiing on the ground at airports. There is an urgent need to reduce aircraft taxiing time on the ground. However, it is too expensive for airports and aircraft carriers to build and maintain more runways, and it is space-limited to tow the aircraft fast using tractors. Autonomous drive capability is currently the best solution for aircraft, which can save the maneuver time for aircraft. An idea is proposed that the wheels are driven by APU-powered (auxiliary power unit) motors, APU is working on its efficient point; consequently, the emissions, fuel burn, and noise will be reduced significantly. For Front-wheel drive aircraft, the front wheel must provide longitudinal force to tow the plane forward and lateral force to help the aircraft make a turn. Forward traction effects the aircraft’s maximum turning ability, which is difficult to be modeled to guide the controller design. Deep reinforcement learning provides a powerful tool to help us design controllers for black-box models; however, the models of related works are always simplified, fixed, or not easily modified, but that is what we care about most. Only with complex models can the trained controller be intelligent. High-fidelity models that can easily modified are necessary for aircraft ground maneuver controller design. This paper focuses on the maneuvering problem of front-wheel drive aircraft, a high-fidelity aircraft taxiing dynamic model is established, including the 6-DOF airframe, landing gears, and nonlinear tire force model. A deep reinforcement learning based controller was designed to improve the maneuver performance of front-wheel drive aircraft. It is proved that in some conditions, the DRL based controller outperformed conventional look-ahead controllers. 相似文献
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为了评估起降阶段的飞机操控特性,针对某型飞机多轮多支柱式起落架系统,研究组成单个起落架支柱的轮胎、缓冲器、刹车系统、前轮转弯等部件的受力、力矩特性及传递过程。基于线性理论,将多个支柱运动特性叠加,运用Matlab/Simulink软件工具,建立整个系统的仿真模型。嵌入某型飞机六自由度运动解算模型进行飞机落震、加速滑跑、高低速转弯、起飞离地、着陆接地、刹车减速等仿真验证,并在某型飞机动基座模拟器上进行飞行试验。结果表明:该起落架模型各项功能完善,能够正确反映飞机姿态响应过程,飞机起降过程感受与真实飞机基本一致。 相似文献
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某型飞机的前轮转弯防摆控制系统,采用了机械单余度,电气双余度的数字式前轮转弯防摆系统,在国内是首次使用的先进技术,与传统的机械-液压系统相比,具有重量轻、布局灵活,实现控制率方便等优点,目前,国外先进的现代飞机大都采用这种形式前轮转弯系统。本文详细阐述了系统的工作原理、系统特点、系统组成及试验分析工作。 相似文献
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王汉斌陆波 《民用飞机设计与研究》2012,(2):57-61
飞机前轮转弯系统是起落架系统的重要组成部分,在对前轮转弯系统进行分析研究的基础上,应用液压仿真软件DSHplus,对前轮转弯液压系统建模仿真。仿真结果与地面试验结果基本一致,验证了模型的准确性。并提出应用频谱分析的方法,对转弯液压系统进行频率响应分析。该方法在设计初期能够增强系统的稳定性,减少研发开支,提高核心竞争力。 相似文献