Go homepage(回首页)
Upload pictures (上传图片)
Write articles (发文字帖)

The author:(作者)aaa
published in(发表于) 2013/12/16 0:32:22
7，500 n variable thrust engine has completed its first show

Last night, the moon lady "three girls" embraces, "the rabbit" arrival of the Moon Palace, detectors this fall, upon drawing a beautiful arc. It sounds easy and romantic, but it's not. Just imagine, 3,780 kilograms of "Leviathan" landing from the 15-km, which is how thrilling! Experts said the researchers "the moon lady", "brain" entered the main deceleration, rapid adjustment, near, hover, moderate speed of obstacle avoidance dropped six "password". According to Xinhua News

　"The power"

Variable speed motor precise speed reducer

Q: over the moon has no atmosphere, Chang, third how slow?

Fell to 15 km altitude from the lunar surface, this soul-stirring 12 minutes were called "black 12 minutes". During this period, almost zero possibility of manual intervention.

Rocket experts, China Aerospace Science and Technology Corporation, the sixth Vice President of the Institute Liu Zhirang: we developed for Chang ' e third variable thrust engine. It towards the goddess Moon, third movement in the opposite direction, which slows down. Only the engine "push" allows to become immortal, the third speed to "become". Chang, third propulsion system consists of four 1-cow variable thrust engine and several attitude control engine components. This engine is the current maximum engine thrust range. This is variable thrust engine's debut in China's aerospace industry.

Overall, Deputy Director of flight control center in Beijing Wu Fenglei: within just a few minutes to become immortal, the third in the navigation, guidance and control system under the command of changing thrust and completed the main deceleration and rapid adjustments. From 1.7 km down to about 50 meters per second per second, height from 15 km to less than 3 km away.

　"Guidance"

Smart "brain" autonomous navigation

Q: when powered down to become immortal, the third is autonomous navigation based on the ground?

Tan Mei Chang-detector systems, third Deputy Commander: foreign peers cannot directly control detector on the ground like this short time known as "dark moments". Can only save program set in advance, Chang e, third "smart enough brain" – navigation guidance and control systems.

Moon lander system Deputy Chief Designer Zhang 熇, third: we have furnished for Chang, third new location speed sensor, and terrain recognition equipment. Navigation guidance and control system combines speed range finder data and topographic data to judge and eventually form a comprehensive policy to control the propulsion system to ensure a smooth landing.

Five Yuan, Party Secretary LI Xian branch of China Aerospace Science and Technology Corporation: power down range velocity sensors play an important role. Ranging speed antenna installed on the lander, as sensitive "horn", sending and receiving radio signals in real time, and promptly passed to the detector control system, a real-time understanding of Chang e, third Lander of velocity and position relative to the surface of the moon.

　　"Hover"

"Eyes," three dimensional imaging to avoid obstacles

Q: the lunar surface is rugged, Chang, third how to ward off rock pit?

Zhang 熇: Chang e in close to one third, optical imaging, wide range of find a flat place was moved to the area. Then 100 meters back when hovering over a flatter small areas.

Tan Mei: hover so that Chang, third to avoid the obstacle, the search for a safe landing area. Chang, third preselection Rainbow Bay landing zone is relatively flat. But lunar surface slopes, rocks and other geological conditions of uncertainty still exist. Chang-third carry ranging gun, three-dimensional laser imaging sensor will be Yu Change the "eyes". They quickly scan the Moon's surface, and draw out the stereo image.

Shanghai Institute of technical physics, CAs Shu Rong researcher: three-dimensional laser imaging sensor measuring range is 50 to 120 metres, about 100 metres from a month began to work providing landing zone terrain information to Chang, third, helping it to avoidance.

"Moon"

Four "joyfulness" leg cushion landing

Q: Chang, first complete the mission hit a month after death of a pretty woman to become immortal, the third how to do soft Moon?

Wu Fenglei: after a rough, fine-avoidance of obstacle avoidance to become immortal, the third when only several meters from the landing sites of their own choosing, into non-powered down. On landing, "the moon lady" vertical speed no greater than 4 metres per second.

Chang-third Sun Zezhou, Chief Designer of the spacecraft system: extraterrestrial probes gasbag floor buffer or cushion legs to become immortal, the third using four landing legs. It was the first spacecraft of the legs.

Lander absorbing components used has excellent mechanical properties, high energy absorption abilities of new material, ensure the lander landed in an easy way without tipping over.

Landing cushion System Designer Yang Jianzhong, Director: this four-legged land under considerable shock, but can guarantee that Chang, third is strong, lightweight, soft, steady fall month.

Chang, third in the schematic diagram of Lunar soft landing

From 1 month 15 km

Main speed reduction

7,500 cattle engine braking, to lower the speed of 57 mph and the detector. Using inertial navigation, and lasers, microwave and speed will be introduced to amend the information

From 2 months 3 km

Quick adjustment

Engine to maintain thrust, dropped 600 metres in height

From 3 months 2.4 km

Close (thick-avoidance)

Maintain the thrust of the engine, by means of optical imaging sensors to monitor the landing zone, determine the landing zone and obstacle avoidance

4 from the lunar surface 100 m

Hover

Detectors remain hovering, essential obstacle detection to the landing zone, using a three-dimensional image sensor observations to the landing zone, select safe landing sites

5-avoidance (essential obstacle avoidance)

According to hover over the safe landing of relative position information, the lander dropped to 30 meters above the landing site. Main engine thrust Adaptive according to the appropriate speed adjustment

6 from the lunar surface 30 m

Slow decline

Maintain the thrust of the engine slow down, down near the lunar surface when the engine shut down, the lander on its own gravity at the Lunar soft landing

(Original title: Chang-how to make the Moon "light work"? ）

　　昨晚，嫦娥“三姑娘”怀抱“玉兔”驾临月宫，探测器这一落，在天宇划出一条美丽的弧线。这听起来轻松浪漫，其实不然。试想，3780公斤的“庞然大物”从15公里高处降落，该是怎样的惊心动魄！专家表示，科研人员在“嫦娥”的“脑子”里输入主减速、快速调整、接近、悬停、避障和缓速下降六道“密码”。 据新华社电

　　【动力】

　　变速发动机精准减速

　　问：月球上空没有大气，嫦娥三号如何实现减速？

　　从15公里高度降至月球表面，这惊心动魄的12分钟被称为“黑色12分钟”。这期间，人工干预的可能性几乎为零。

　　火箭专家、中国航天科技集团公司第六研究院副院长刘志让：我们为嫦娥三号量身研制了变推力发动机。它朝着嫦娥三号落月运动的反方向作用，从而实现减速。只有发动机“推得精”，嫦娥三号的速度才能“变得准”。嫦娥三号推进分系统由1台7500牛变推力发动机和若干台姿控发动机组成。这台发动机是我国目前推力变化范围最大的发动机。这是变推力发动机在我国航天事业中的首秀。

　　北京飞控中心总体室副主任吴凤雷：短短几分钟内，嫦娥三号在导航制导控制系统的指挥下改变推力大小，完成主减速和快速调整。速度从每秒1.7公里降至大约每秒50米，高度从15公里降至不到3公里。

　　【制导】

　　聪明“大脑”自主导航

　　问：动力下降时，嫦娥三号是自主导航还是根据地面指令行动？

　　嫦娥三号探测器系统副总指挥谭梅：国外同行把类似这种地面无法直接控制探测器的短暂时间称为“黑色瞬间”。只能事先把程序设定好存进去，让嫦娥三号有“足够聪明的大脑”——导航制导控制系统。

　　嫦娥三号着陆器分系统副总设计师张熇：我们为嫦娥三号装备了全新的测距测速敏感器以及地形识别设备。导航制导控制系统将测速测距数据和地形数据结合判断，最终形成一套完善的策略来控制推进系统，确保实现平稳降落。

　　中国航天科技集团公司五院西安分院党委书记李军：动力下降段测距测速敏感器发挥重要作用。安装在着陆器上的测距测速天线，像灵敏的“触角”，实时收发射频信号，并及时传递至探测器控制系统，实时掌握嫦娥三号着陆器相对于月球表面的速度和位置。

　　【悬停】

　　“双眼”三维成像避障碍

　　问：月面崎岖不平，嫦娥三号如何避开岩石大坑？

　　张熇：嫦娥三号在接近段有一次光学成像，先大范围找一个相对平的地方挪到那附近。然后一百米悬停的时候再找一个更平坦的小范围。

　　谭梅：悬停的目的就是让嫦娥三号避开障碍、搜索安全着陆区。嫦娥三号预选着陆区虹湾相对平坦。但月球表面仍然存在坡度、石块等不确定地质条件。嫦娥三号携带的测距测速仪，激光三维成像敏感器等就相当于嫦娥的“眼睛”。它们对月球表面快速扫描，并绘制出立体影像。

　　中科院上海技术物理研究所舒嵘研究员：激光三维成像敏感器的测量范围是50至120米，大约从距月面100米处开始工作，为嫦娥三号提供着陆区三维地形信息，帮助它避障。

　　【落月】

　　四条“轻功”腿缓冲着陆

　　问：嫦娥一号完成使命后撞月香消玉殒，嫦娥三号如何做到轻柔落月？

　　吴凤雷：经过粗避障、精避障，嫦娥三号距离自己选择的着陆点只有数米时，进入无动力下降。着陆时，“嫦娥”的垂直速度不大于4米每秒。

　　嫦娥三号探测器系统总设计师孙泽洲：地外探测器的落地缓冲可以用气囊或者缓冲腿，嫦娥三号采用了四条着陆腿。它因此成为我国第一个带腿的航天器。

　　着陆器缓冲吸能部件，采用了一种具有优异力学性能、高吸能本领的新材料，确保着陆器以舒适的方式着陆，而不翻倒。

　　着陆缓冲分系统主任设计师杨建中：这四条腿着陆时承受巨大的冲击，却能保证嫦娥三号强、轻、柔、稳地落月。

　　嫦娥三号在月球软着陆示意图

　　1距月面15公里

　　主减速段

　　利用7500牛发动机进行制动，将探测器的速度降至57米/秒。采用惯性导航，并引入激光、微波测距和测速信息进行修正

　　2距月面3公里

　　快速调整段

　　发动机维持一定推力，高度下降600米

　　3距月面2.4公里

　　接近段(粗避障)

　　发动机维持一定推力，通过光学成像敏感器对着陆区进行监测，确定安全着陆区并避障

　　4距月面100米

　　悬停段

　　探测器保持悬停状态，对着陆区进行精障碍检测，使用三维成像敏感器对着陆区进行观测，选择安全着陆点

　　5避障段(精避障)

　　根据悬停段给出的安全着陆点相对位置信息，着陆器下降至着陆点上方30米。主发动机推力根据相应速度进行自适应调整

　　6距月面 30米

　　缓速下降段

　　发动机维持一定推力缓慢下降，降至月面附近时发动机关闭，着陆器依靠自身重力在月面软着陆

（原标题：嫦娥怎样炼成落月“轻功”？）

赞