标签: rocket

Oh what horror! As you may know, I currently hang my hat in Huntsville, Alabama, home of the US Space and Rocket Center and NASA's Marshall Space Flight Center . I've been told that there are more rocket scientists per square foot in Huntsville than anywhere else in America, and that's saying something. In fact, there's a joke here in town that, if someone says, "Well, it doesn't take a rocket scientist to do that," half the people in the room look disappointed and leave (LOL).   The really exciting news is that registration is now open for next year's NASA Human Exploration Rover Challenge , which will be held April 16-18 at the US Space and Rocket Center. This challenge is open to teams from high schools, colleges, and universities from around the world. The challenge involves designing and building a human-powered rover, which reflects NASA's interest in exploring planets, moons, asteroids, and comets.   Each student team will comprise six members. Two members of each team (one male and one female) will power their team's rover over a half-mile obstacle course that simulates an extraterrestrial terrain, including craters, boulders, ridges, inclines, and crevasses.   (Image: NASA)   A few days ago, I was delighted to have the opportunity to meet up with Human Exploration Rover Challenge project manager Diedra Williams, volunteer coordinator and education program specialist Amy McDowell, and university affairs officer (and all-around technical guru) Dr. Frank Six. This meeting was kindly organized and coordinated by Angela Storey, public affairs officer for the Rover Challenge competition.   As you will see from the Rover Challenge website, there are all sorts of interesting technical restrictions. For example, the entire rover must be capable of being packed into a 5x5x5-foot cubic crate. Also, no energy storage components are permitted -- everything must be human powered.   This is actually a huge undertaking. Based on previous challenges, the organizers expect up to 100 teams to register. (Registration closes Jan. 9 for international teams and Feb. 6 for US teams.) In addition to the 600 students and their parents/supervisors, the race itself is staffed by more than 300 volunteers, including employees from the Marshall Space Flight Center, representatives from sponsoring companies, and members of the community.   There's also a "pit crew" staffed by 50 technicians and engineers -- accompanied by just about every tool available, including welding equipment -- who are on hand to help the students fix any problems with their rovers. These experts don't actually do the work; instead, they teach the students how to do it themselves.   This all sounds tremendously exciting. I cannot tell you just how much I would have loved to have taken part in something like this challenge when I was at high school or at university.   In our meeting, the folks from NASA were telling me some of the interesting things that have happened in previous challenges, and how the course is constantly evolving to include new trials. There will be a big emphasis on creating a Mars-like environment for the forthcoming challenge. Also, the 2015 course will include new obstacles, including a five-foot climb, which is a lot harder than you might expect when you are powering one of these rovers.   In addition to teams from all over America, the folks at NASA were bragging about the participants they've had from around the globe in previous challenges. They were reeling off the names of countries like Russia, Canada, India, Romania, Mexico, the United Arab Emirates, Italy, Germany, and even France, for goodness sake.   Eventually, they ran dry without mentioning my home country. "What about England?" I asked, with only a little quaver in my voice. They all looked sad, and then someone said in a doleful voice, "I'm afraid that no team from the United Kingdom has ever taken part."   Well, this was a blow, and no mistake. I mean to say, it's a sad state of affairs when a country like France is represented on the international stage while England is nowhere to be seen. I cannot believe my ears. I hang my head in shame. It's probably too late for an English school or university to create a vehicle and field a team for the 2015 Rover Challenge, but -- as the folks from NASA pointed out -- anyone can come over to observe and report back to home base in anticipation of attending a future challenge.   Speaking of which, I'm going to make it my personal mission to ensure England is represented in the 2016 Rover Challenge. Yes, of course, I'd also be happy to see contenders from the rest of the United Kingdom, including Northern Ireland, Scotland, and Wales, but I'm only one man, and I can only do so much, so I'm afraid I will have to focus my attentions on England for the moment. So long as we trounce the French, I can die a happy man (LOL).   In particular, I'm hoping to persuade my alma mater, Sheffield Hallam University, to field a team. I'm planning on contacting my old engineering department as soon as I can. Perhaps I can even persuade some UK space-related companies to sponsor the "Max's Marauders" team (don't worry, this name is just a place-holder). Ooh, just a moment, my chum Adam Taylor is head of the Engineering -- Systems for the Space Stream -- High Performance Imaging Solution Division at e2v . Some of the imaging systems on the Rosetta space probe were created by e2v. I wonder.   Adam... incoming!  

  最近在摸索  V5的 rocket io 的使用   ，主要收获如下   1  GTP  时钟    GTP 的时钟源可以有 三种提供方式    1,  相邻的  GTP_TILE   2.  从差分端 经过 IBUFDS输入，应为 GTP 为  一对 公用 一个PMA_PLL，则GTP0 可以直接使用GTP1的用户时钟，如TXUSRCLK时钟，但在接收端需要使用自己独立的时钟   RERXCCLK   恢复时钟，或则使用公共的TXUSRCLK  但必须使用频率矫正，如为16bit 端口宽度  则 useclk2  =useclk/2   2 复位  所有的GTP  设计必须复位，使用 PLLLKDET_OUT做DCM  及PLL 的复位信号， PLLKDET_OUT完成 后 变高，则DCM退出复位，   然后 RXRECCLK 时钟锁定，DCM锁定，LOCKED 信号有效，rxusrclk 被锁定，而此时 DCM及PLL的LOCKED 信号作为 GTP TX与RX 的复位信号， RX-TX退出复位状态，开始工作      3 对齐 comma对齐是必须的，对齐的序列由ALIGN_COMMA_WORD设置，合法边带间隔由INTDATAWIDTH定义，边带位置数由RXDATA字节数定义，通常不GTP默认的对齐序列 为 K28.5，接收机在字符中搜寻对齐序列字符，一旦找到 ，将对齐到此字符边界，并将通常此序列也作为时钟修正序列，将RXENMCOMMAALIGN拉高，使能负命令对齐功能，任何符合对齐命令的模块都将引起命令重对齐，在成功对齐后，RXBYTEISALIGNED 将拉高，此时将命令对齐使能关闭以保持此时的对齐， 4时钟修正 对于非同源时钟驱动的TX与RX，时钟修正是必须的，使用rxrecclk可以不修正 由于任何两个不同源的时钟总存在一定的频率差，对于 GTP来说 由于频率不同步，将产生字符丢失      1，CLK_CORRECT_USE  设为 TRUE      2，设置时钟校正序列 CLK-COR_SEQ_1     3，RXbuffer  极限值设置     4, CLK_COR_ADJ_LEN用于设置子序列数目，如果内部数据位宽为10bit，则时钟校正电路适配所有10bit 大的每个子序列     4.8B/10B     1，字符运行一致性检查     2，K码指示RXCHARISK     3,命令检查 DEC_PCOMMA_DETECT is TRUE，RXCHARISCOMMA有效     4，限制命令触发 DEC_VALID_COMMA_ONLY   K28.1 , K28.5,K28.7 因为他们都有一样的8/10B头   5，通道绑定   1，发送器同时在所有线上发送一个虚序列模式，来调整每路LANE的延迟    2，使能每个GTP收发器的通道绑定功能    3，设置主通道  CHAN_BOND_MODE 为TRUE   主通道 CHAN_BOND_LEVEL设为1   4， 设置 从通道为CHAN_BOND_MODE=SLAVE     从通道 CHAN_BOND_LEVEL设为 0       5，连接通道绑定端从 MADTER到 每个SLAVE，或者直接使用菊花链     6，设置通道绑定序列 和检测参数 CHAN_BOND_SEQ_LEN设置子序列长度 1-4 CHAN_BOND_SEQ_1*设置序列值，如CHAN_BOND_SEQ_2_USE 为TRUE，CHAN_BOND_SEQ_2*设置2的序列值，子序列有效激活的位数由 内部数据宽度和RX_DECODE_SEQ_MATCH决定， 设置最大偏移 ----当主通道接收到通道绑定序列 ，将不立即触发通道绑定，猪头感到必须等待一些时钟，否则 慢的通道可能还未接收到绑定序列，时钟校正和通道绑定电路一起执行，正常的他们不会冲突，除非通道绑定事假和时钟校正同时发生，这种情况，一个电路必须优先，确保时钟校正有更高的优先级，CLK_COR_PRECEDENCE设置为TRUE         6 使用 TX/RX phase Alignment    1   bypass buffer  减少延迟，但此时 时钟校正和通道绑定无效，RX 时钟源必须使用RXRECCLK，   2， RX_SXCLK_SEL设置为  RXUSR   3，由 RXRECCLK驱动 RXUSECLK  4，使用GTPRESET或 CDRreset 复位RX数路径  5，等待 PMA PLL好 RXUSRCLK  DCM 或PLL  LOCK  6 等待CDR锁定 提供一个稳定的RXRECCLK  7，驱动RXPMASETPHASE 为高32个用户周期后，释放   ,                      

When it came time to select my senior design project it seemed fitting to do something along the lines of avionics since I had been working as a software engineer at an avionics manufacturer for four years. So I chose to design a rocket avionics card that would monitor flight characteristics, deploy two parachutes at the proper time, and help you find the rocket once it returned to the ground. Once the design was done and made it through the standard review process design by my professor, it was time to build and test the system. Due to the usual issues associated with supply chains I was already well behind schedule by the time the parts arrived and I began assembling the hardware. It basically came down to having 48 hours to assemble the circuit, test the software that I had mostly completed but never tested, and package the system into a payload bay for a high powered rocket launch. Since the launch event was coordinated with a local amateur rocketry club and the next event was well after my project due date, I could not miss the deadline or I would not be graduating that year. Needless to say, the phrase "failure is not an option" was forefront in my mind over that 48 hour period! Once I had the circuit assembled and had the USB communication link between it and my computer, I thought the rest was going to be smooth sailing. Any engineer reading this is probably laughing hysterically at this point since "smooth sailing" prior to an upcoming deadline is a fantasy held only by overly optimistic junior engineers. With only a day left, I began working the bugs out of my code and got the various features of the device working. After a short time I could save data from the pressure sensor and accelerometer to the EEPROM and dump that data over the USB port to the PC and I could manually force the electrical outputs that were designed to ignite the parachute deployment charges to cycle on and off. Everything seemed to be working great so off I went to the university's physics department to use the pressure chamber to test my system. Upon arriving at the pressure chamber I learned that it had broken the day before and it was the only chamber on campus. I now had no way to test if my algorithms to convert the sensor data through the ADC inputs were correct. If they were wrong then the parachute charges would be ignited at the wrong time which would present a serious safety threat to launch attendees. If I could not find a way to test the system then I would not be able to launch it and graduate the following month. So I did what any smart engineer would do at this point; ask an even smarter engineer for their advice. In this specific case, I drove over to my parents' house and consulted with my dad who was designing circuits long before I was even born. We needed to find or create a pressure chamber of some sort that would fit my circuit card and test it from ground level up to at least 20,000 feet ASL (which, in Central Florida, also happens to be 20,000 feet AGL). While we were sitting at the table brainstorming ideas my mom was working on canning (i.e. jarring) tomatoes from the recent harvest of their garden. Tomatoes... Jarring... Glass Jars... Eureka! With only 10 hours left before I had to be at the launch event we began hacking together a pressure chamber using two glass masonry jars, a few valves, and an automotive vacuum pump. One jar was the reservoir and the other held the avionics card. A little bit of physics and math determined the algorithm used to find the pressure needed in the reservoir to equalize with the other jar that represented a specific altitude. Thus, using the pump and valve system, we were able to simulate a rocket's accent and decent by creating a vacuum in the jar with the circuit card and then equalizing it with the normal atmospheric air around it. Using this hacked together pressure chamber I found a few bugs in my algorithm and was able to fix them prior to the launch event. After a successful flight and a few weeks of documentation writing, I presented my design along with the masonry jar pressure chamber to the senior design judges at the university's showcase event. A few of the judges were actual rocket scientists from NASA and they really enjoyed the story behind the pressure chamber. In the end, my project won the Best in Show award in the Computer Engineering category and it was all thanks to a jar full of tomatoes. - Terry Reinert Terry Reinert is a software engineer, karate instructor, and amateur photographer residing in Central Florida.