chariot

   



   chariot月球車(chē)是NASA的最新月球車(chē)，12月份才經(jīng)過(guò)測(cè)試。NASA花了7個(gè)月的時(shí)間研制，這個(gè)龐然大物比一般月球車(chē)大，可以載7到8人。是NASA重返月球計(jì)劃的月球車(chē)測(cè)試品。下面是NASA提供的資料：
In preparation for the US led effort to build a lunar outpost, NASA has completed the first lunar truck prototype, named Chariot. Realizing the importance of crew and payload mobility on the lunar surface, the Exploration Technology Development Program&＃039;s Human-Robotics Systems Project set out, in Apollo-like style, to build a lunar truck and the team that could shepherd future lunar truck efforts. With only one year to design, manufacture, and assemble Chariot, NASA, teamed with companies from all across America, conquered the challenge.
Chariot was operational and unveiled to the entire agency only eleven months after the beginning of the project. The vehicle is designed to meet the payload transport, range, terrain and speed specifications defined by NASA’s Lunar Architecture Team. Chariot will serve as a 1g-scaled system for technology evaluation and EVA/Ops field testing. It&＃039;s design incorporates many of the lessons learned from the Apollo rovers, as well as trucks that we drive every day. However, the team also needed to challenge many basic assumptions about what a lunar truck might be - Should it have four wheels? Should people sit on seats? Should it have passive suspension? Should it steer like a car?
These challenges pressed the Chariot engineering team into the design and development of prototypes to answer these and other questions. The Lunar Architecture Team reviewed numerous design options, evaluating vehicle types and scales against mission requirements, launch limits and cost constraints. The Chariot was designed as a 1g (Earth) version of a Lunar Truck, able to work around a construction site like a utility vehicle. The system is sized to be able to carry a mixed suited crew, or combinations of crew and surface payloads such as tools, science equipment, and samples. Chariot’s chassis can be reconfigured to serve as an unpressurized lunar truck, with crew riding onboard in suits, or as a pressurized rover when it is outfitted with a small cabin. Pairs of Chariots can be used to extend crew surface ranges beyond walking distances, expanding the exploration horizon beyond the limits accepted by Apollo crews.
The development of Chariot and, more importantly, the lunar truck team has positioned America in an excellent position to develop a very robust and useful truck to be transported hundreds of thousands of miles away to become the workhorse of the lunar surface. The Chariot project positions NASA as a “smart buyer” of surface vehicles in advance of the System Requirement Review (SRR) and Preliminary Design Review (PDR) dates for Lunar Surface Systems.
Key Design Specifications
Chariot Spec Earth Prototype (1g) Lunar System (1/6g)
  
Payload 1000 kg 3000-6000 kg
Vehicle Mass 2000 kg 1000 kg
Top Speed 20 KPH 20 KPH
Slope Climbing 15 Deg 25 deg
Range 25 Km 100 Km


Chariot
測(cè)試網(wǎng)絡(luò)吞吐量的利器
Chariot測(cè)試網(wǎng)絡(luò)吞吐量的利器
    網(wǎng)絡(luò)測(cè)試的方法和手段因測(cè)試的目的不同而有所不同。典型的網(wǎng)絡(luò)設(shè)備測(cè)試的方法有2種：第一種是將設(shè)備放在一個(gè)仿真的網(wǎng)絡(luò)環(huán)境中，通過(guò)分析該產(chǎn)品在網(wǎng)絡(luò)中的行為對(duì)其進(jìn)行測(cè)試；第二種方法是使用專(zhuān)用的網(wǎng)絡(luò)測(cè)試設(shè)備對(duì)產(chǎn)品進(jìn)行測(cè)試，如專(zhuān)用的性能分析儀器SmartBits 2000、IXIA 1600 等。對(duì)于網(wǎng)絡(luò)系統(tǒng)的布線(xiàn)測(cè)試、物理連通性的測(cè)試和故障監(jiān)測(cè)也有專(zhuān)門(mén)的工具，這些工具是一些底層的網(wǎng)絡(luò)測(cè)試和維護(hù)工具，如Fluke 公司的網(wǎng)絡(luò)聽(tīng)診器、網(wǎng)絡(luò)一點(diǎn)通、企業(yè)級(jí)網(wǎng)絡(luò)測(cè)試儀等等。而網(wǎng)絡(luò)電纜測(cè)試儀、令牌環(huán)網(wǎng)測(cè)試儀、以太網(wǎng)測(cè)試儀還有光纜測(cè)試儀等等，都是在網(wǎng)絡(luò)系統(tǒng)的實(shí)施部署和運(yùn)行維護(hù)階段采用的常用的測(cè)試工具。對(duì)于網(wǎng)絡(luò)協(xié)議的一致性測(cè)試一般有專(zhuān)門(mén)的測(cè)試工具來(lái)支持，比如說(shuō)對(duì)ISDN、ATM、ADSL、幀中繼等的實(shí)現(xiàn)都有專(zhuān)門(mén)的測(cè)試儀。
    對(duì)網(wǎng)絡(luò)系統(tǒng)的測(cè)試也有相應(yīng)的測(cè)試工具，最典型和最重要的就是網(wǎng)絡(luò)協(xié)議分析儀。網(wǎng)絡(luò)協(xié)議分析儀一般有專(zhuān)用的硬件設(shè)備和專(zhuān)門(mén)的軟件。這類(lèi)協(xié)議分析儀典型的功能是數(shù)據(jù)包的捕捉、協(xié)議的解碼、統(tǒng)計(jì)分析和數(shù)據(jù)流量的產(chǎn)生。用協(xié)議分析儀我們可以捕捉網(wǎng)上的實(shí)際流量、提取流量的特征，據(jù)此對(duì)網(wǎng)絡(luò)系統(tǒng)的流量進(jìn)行模型化和特征化。此外，網(wǎng)絡(luò)協(xié)議分析儀還可以主動(dòng)地產(chǎn)生大量的數(shù)據(jù)包施加到網(wǎng)絡(luò)上，分析網(wǎng)絡(luò)的響應(yīng)或?qū)�網(wǎng)絡(luò)系統(tǒng)進(jìn)行加重測(cè)試。目前典型的協(xié)議分析儀有HP 公司的Internet Advisor(網(wǎng)絡(luò)專(zhuān)家系統(tǒng))、WG 公司的Domino 系列協(xié)議分析儀等。另外還有一些純軟件的協(xié)議分析工具，有些甚至可以從網(wǎng)上免費(fèi)下載。但這類(lèi)協(xié)議分析軟件無(wú)論在協(xié)議的解碼能力、解碼和數(shù)據(jù)分析的實(shí)時(shí)性以及數(shù)據(jù)流量的產(chǎn)生能力上與用專(zhuān)門(mén)硬件實(shí)現(xiàn)的協(xié)議分析儀相比仍有差距。
    還有一些比協(xié)議分析儀更高層次的網(wǎng)絡(luò)性能測(cè)試工具，站在應(yīng)用層的角度使用一些基準(zhǔn)流量對(duì)網(wǎng)絡(luò)系統(tǒng)的性能進(jìn)行分析，代表性的軟件是Ganymede Software 公司的Chariot 軟件......


   

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