Slashdot Mirror
Cross Country Solar Race
"Many teams (as well as Iowa State) are using advanced technologies like lithium batteries, near space-grade solar cells, and composite materials such as carbon fiber and fiberglass in their cars. Additionally many of us are utilizing Linux with amateur radio and satellite data phones to monitor weather conditions and to help optimize energy usage.
"We run a LinuxPPC server in our solar car chase vehicle that receives GPS coordinates from a Motorola Encore GPS receiver that is driven by a Lineo uCdimm board running uClinux. The uCdimm board reads in the GPS coordinates and broadcasts the coordinates every second via UDP packets on the ethernet network in the van. The LinuxPPC machine uses the coordinates to track our position and to display upcoming route information (stop lights, turns, road contitions) and to aid our racing strategy. Additionally, the LinuxPPC machine connects to the Internet via a Globalstar satellite phone to periodically download weather maps and forecasts for our current location. We also use GPS and amateur radio with APRS in our other support vehicles to monitor all of our vehicles' positions.
"Most of the code that runs everything is developed in house with C/C++, some of it with the Qt library. Myself and another member of our team will be preparing a detailed presentation in September for our local Unix users group about how we've utilized Linux on our team. If there is interest, I'll post the URL here for that once we've got it prepared.
"A list of other teams competing in ASC next week is available online at the American Solar Challenge web site. Most are university teams from North America, but there are some international teams as well."
1. Does the race route have to be carefully planned to avoid long tunnels or deep forests?
The race is carefully planned. not so much for tunnels and forests, but more for safety. Avoiding interstates, and avoiding small towns (i.e. traffic) are both good ideas, although seem to be in conflict with each other. It takes the race organizers the better part of a year to plan the route.
2. What sort of percentage of maximum speed is attainable on a cloudy day (compared to a sunny day)?
The speed is not a function of sun (at least not directly). These are electric vehicles, powered by batteries. The more sun, the slower you drain your batteries.
3. Do the cars carry batteries as a backup in case of sudden eclipses etc. that block out the light briefly?
Yes.
4. If batteries (or some other energy store) are carried, how much running time can be added before the weight of the storage reduces the efficiency to a point where it'd be better to just run off solar power?
The rules of the race limit the amount of batteries you can carry (ex: Li-ion=30kg). After the first few days of a race, teams typically run only off the sun, using power from the batteries only in the morning/evening/cloudy periods.
5. Do you ever get kids who think it's funny to throw tins of paint at your cars to cover the photovoltaic cells?
Kids (and adults) are always a risk. They never realize that the paper thin silicon they are about to touch is worth more than them. For this reason, when they are on display, the cars are never left unguarded. I haven't heard of any intentional vandalism though.
6. What sort of a drain on the speed is the Linux-GPS setup?
I beleive this setup was in the support van, not the solar car. The rules allow auxiliary batteries (replacable) to be used to power telemetry equipment, so this is not an issue.
7. Just how fast do these cars go anyway? Are we talking Smokey and The Bandit or what?
Honda (WSC 96) attained a maximum speed of 138km/hr. I beleive this is still the record. More typical max speeds are between 100-115 km/hr. Typical average race speeds are around 70-85 km/hr although can reach higher speeds depending on the terrain.
Rob
Midnight Sun Solar Car Team
>>Unless it clouds over in which case it can take much longer to get to the finish line.
I attend Iowa State, and I was on the Solar Car team my Freshman year. The race they had the year before I joined, was pretty much clouded over the whole time. With high efficiency solar cells, the car still receives energy, just not as much. This is why, in these races, strategy is a must.
>I also wouldn't be suprised if they incorporated some sort of energy reclamation system into the brakes (like the one on the Honda Insight) to help keep the battery charged.
The car we had then did have regenerative braking. Part of strategizing was determining whether it saved more energy on a hill to brake, and reclaim energy, or to give the car more speed, to make it over the next hill.
These solar cars can go surprisingly fast. The car before the Oddysey could go upwards of 60mph, although it was really hard on the engine. The previous car probably weighed much more than the current one, since the old one had lead-acid batteries, and the new one has more advanced - lighter batteries.
Time flies like an arrow, Fruit Flies like bananas.
- Does the race route have to be carefully planned to avoid long tunnels or deep forests?
- What sort of percentage of maximum speed is attainable on a cloudy day (compared to a sunny day)?
- Do the cars carry batteries as a backup in case of sudden eclipses etc. that block out the light briefly?
- If batteries (or some other energy store) are carried, how much running time can be added before the weight of the storage reduces the efficiency to a point where it'd be better to just run off solar power?
- Do you ever get kids who think it's funny to throw tins of paint at your cars to cover the photovoltaic cells?
- What sort of a drain on the speed is the Linux-GPS setup?
- Just how fast do these cars go anyway? Are we talking Smokey and The Bandit or what?
Cheers. I look forward to being enlightened.where their vehicles will be commandeered by the state and used to provide an alternative energy source to PG&E.
Athletic Scholarships to universities make as much sense as academic scholarships to sports teams.
Actually, you could be quite right here, Michael. In the wonderful, corporate-sponsored brainwas^H^H^H^H^H^H^H^H educational world of Disney Worlds Epcot there is an Exxon sponsored "History of Energy" run.
Allthough it's a fun run, it nearly made me barf. The kiddies are told The "history" of energy purely from the sponsors perspective and agenda. The fact that energy could actually be conserved and used responsibly was just ridiculed in one snide side remark.
It was then, when I realised that Disney is a truely and absolutly evil corporation, unmatched even by M$.
ich bin der musikant
mit taschenrechner in der hand
kraftwerk
This is obviously not a Microsoft sponsored race! Damn Universities! Don't you know you're suppose to get prior approval from Microsoft before you do such things??
*QH picks up the red Microsoft phone on his desk*
QH: Bill...We have a situation. The free thinkers are at it again...
Scientist...
Geesh...
LFS. Have you built your system today?
I'd never heard of that 'Route 66' before, but when you mentioned the fabled freeways of song and television - Interstates 55, 44, and 40 - it just came to life, man. Thanks.
+5:offtopic,but anti-American
Unless it clouds over in which case it can take much longer to get to the finish line.
Probably, but not much longer. Many of the designs (if not all of them) incorporate some sort of battery system. The solar cells provide energy to drive the motor, but they also charge a battery to be used when it's not as bright out/overcast. I also wouldn't be suprised if they incorporated some sort of energy reclamation system into the brakes (like the one on the Honda Insight) to help keep the battery charged.
Granted, a couple days of serious overcast/thunderstorms would cause quite a bit of delay, but then the car that was most efficient would probably have an advantage (having larger energy reserves, being able to build power on lower light levels). That's the cool thing about engineering races.
Say "NO!" to tax money for religious groups.
n.
A movement from one place to another, as on a stage; a crossing.
So, cross country is moving from one place to another, within a country. Oh look - that's what they're doing. Now give it a rest, please.
Um, get a government not run by guys from Big Oil...
Be part of the world's largest collaborative work of art: http://www.paintthemoon.org
http://www.acs.org/nsa/intcong.htm
Sure, not all the teams are using them - but many are, and this is sure to change the dynamics (if not the outcome) of the race.
We're talking 150% greater efficiency here, and at lower cost.
The photovoltaics is the interesting story - after all, we all could guess that many participants are using Linux and GPS!