Some of you have expressed interest in buying your own kit to work with and play with.
This was the lowest price I found for the "Rock-it" Robot (be aware that kits come with solder and nonsolder options -- we use the non-solder options):
http://www.owirobots.com/cart/index.php?l=product_detail&p=6
Here's the Jungle Bot:
http://www.owirobots.com/cart/index.php?l=product_detail&p=14
Here's a cute and cheap little solar powered "king crab" robot:
http://www.owirobots.com/cart/index.php?l=product_detail&p=23
Friday, May 09, 2008
Thursday, May 08, 2008
A short list of building tips and tricks
Get your own screwdriver kit. You should have a variety of sizes (most important are the Phillips screwdrivers -- the average cheap kit should do just fine.) The ones in the lesson kits aren't bad, but it's faster to work on kids' problems if you have your own set of screwdrivers.
Include a pair of needlenose pliers. They're good for getting out stripped screws -- and you can expect a lot of stripped screws in these classes.
A magnetic screwdriver is handy... BUT it also can put the motherboard at risk. The 1's and 0's in computer code are stored magnetically, and putting a magnet too near a chip will erase the programming on that chip. This is not a good idea when you're dealing with robots.
Use the magnets to find dropped screws on the floor.
Have kids put the parts they're not working on back in the bag and in their boxes and keep them there. Only have them do a few screws/nuts/bolts at a time to reduce the possibility of parts getting dropped on the floor.
(additional tips are welcome)
Include a pair of needlenose pliers. They're good for getting out stripped screws -- and you can expect a lot of stripped screws in these classes.
A magnetic screwdriver is handy... BUT it also can put the motherboard at risk. The 1's and 0's in computer code are stored magnetically, and putting a magnet too near a chip will erase the programming on that chip. This is not a good idea when you're dealing with robots.
Use the magnets to find dropped screws on the floor.
Have kids put the parts they're not working on back in the bag and in their boxes and keep them there. Only have them do a few screws/nuts/bolts at a time to reduce the possibility of parts getting dropped on the floor.
(additional tips are welcome)
Cool Robots
A small sampling of interesting robots:
Pleo is one of the newest robot toys on the market. This is an adorable little guy, about the size of a cat, with many play behaviors. He can learn certain things and in some respects acts as though he's alive. I have friends who own one, and I want one, too!
Pi-Tronics: this is a home builder's page and he has a number of easy robotics projects using cheap materials on his page.
Boston Dynamic's BigDog robot another one of my favorites. Built like an animal, it can carry packs, hop, jump, and walk around on very slippery ice without falling over. It models its motion from animal motion -- the video shows how it can recover its balance on a slippery surface. You almost forget that it's a machine that you are watching.
Leghorn is a "battle robot" from Japan. This small robot, which looks like a cartoon chicken, is one of the world's top "battlebots" in the lightweight division.
Honda's Asimo robot looks like a human and can speak and dance. I did see a performance piece where several Asimos danced a traditional Japanese dance in unison.
The Ever-1 Robot looks very human -- she blinks, moves her head, and gestures although if you look closely the movements are not completly convincing. She speaks and can understand around 400 words. One possible use for her is in information booths -- the Japanese don't like asking strangers for information and direction (I am glossing over some very complex cultural behaviors here... while the "don't like asking" is not precisely correct, it's close enough for a basic understanding.)
The Roomba vacuum cleaner -- this one is a great little robot that cleans up your house while you do other things. We have several -- a good investment for busy people. The I-Robot corporation also makes other interesting robots.
There's also a robot lawn mower. I don't have one, but I want one!
Lego Mindstorms is a wonderful robot building kit. I have several and they're fun to play with. The advantage of these is that you can build and rebuild robots into new configurations. Although the instruction set is fairly simple, people have built some odd and interesting projects with Lego Mindstorms.
The kits that we use in class come from the Omnico OWI robots. They make wonderful project kits for all levels of robot builders.
Pleo is one of the newest robot toys on the market. This is an adorable little guy, about the size of a cat, with many play behaviors. He can learn certain things and in some respects acts as though he's alive. I have friends who own one, and I want one, too!
Pi-Tronics: this is a home builder's page and he has a number of easy robotics projects using cheap materials on his page.
Boston Dynamic's BigDog robot another one of my favorites. Built like an animal, it can carry packs, hop, jump, and walk around on very slippery ice without falling over. It models its motion from animal motion -- the video shows how it can recover its balance on a slippery surface. You almost forget that it's a machine that you are watching.
Leghorn is a "battle robot" from Japan. This small robot, which looks like a cartoon chicken, is one of the world's top "battlebots" in the lightweight division.
Honda's Asimo robot looks like a human and can speak and dance. I did see a performance piece where several Asimos danced a traditional Japanese dance in unison.
The Ever-1 Robot looks very human -- she blinks, moves her head, and gestures although if you look closely the movements are not completly convincing. She speaks and can understand around 400 words. One possible use for her is in information booths -- the Japanese don't like asking strangers for information and direction (I am glossing over some very complex cultural behaviors here... while the "don't like asking" is not precisely correct, it's close enough for a basic understanding.)
The Roomba vacuum cleaner -- this one is a great little robot that cleans up your house while you do other things. We have several -- a good investment for busy people. The I-Robot corporation also makes other interesting robots.
There's also a robot lawn mower. I don't have one, but I want one!
Lego Mindstorms is a wonderful robot building kit. I have several and they're fun to play with. The advantage of these is that you can build and rebuild robots into new configurations. Although the instruction set is fairly simple, people have built some odd and interesting projects with Lego Mindstorms.
The kits that we use in class come from the Omnico OWI robots. They make wonderful project kits for all levels of robot builders.
Robots - Part two
In general, physical robots consist of 3 main parts: a programmable "brain", one or more moving parts, and one or more sensors. The "brain" may come pre-programmed so that the user is not able to change the behaviors of the robot. One of the most commonly used robot "brains" is the Basic Stamp http://en.wikipedia.org/wiki/BASIC_Stamp It's relatively easy to program this chip, and you can create a wide range of behaviors for it.
The company's home page has a lot of tempting robots and components http://www.parallax.com/
Choice of "brain" (and added memory) is the most important factor in determining what a robot can do and how easy it is to program. Needless to say, industrial robots do not use Basic Stamp chips as their "brains."
Choice of power supply also dictates how much a robot can do. It takes a lot of power to move a 150 pound humanoid machine -- only recently have robots like ASIMO been able to step away from the power cord for a few hours at a time.
A simple, programmable web emulation robot can be found here: http://home.att.net/~David.D.Barnett/tutorial.html You can program Karel to do a number of differet behaviors.
The company's home page has a lot of tempting robots and components http://www.parallax.com/
Choice of "brain" (and added memory) is the most important factor in determining what a robot can do and how easy it is to program. Needless to say, industrial robots do not use Basic Stamp chips as their "brains."
Choice of power supply also dictates how much a robot can do. It takes a lot of power to move a 150 pound humanoid machine -- only recently have robots like ASIMO been able to step away from the power cord for a few hours at a time.
A simple, programmable web emulation robot can be found here: http://home.att.net/~David.D.Barnett/tutorial.html You can program Karel to do a number of differet behaviors.
Robots - part one
Robot Basics
The most basic definition of robotics (that everyone agrees upon) is that it is a science that uses technology to design and make machines that do very specific tasks -- and which can also react to the environment in some way.
The line between what we call a robot varies from culture to culture (Japan's definition is a bit differen than ours) -- and the forms that the robots take are different from ours as well. Most robots today are used to make cars and appliances, or to work in some areas of nuclear plants and chemical plants where it woule be too dangerous for a human. The military and police also use robots to defuse bombs and to look into places where they think snipers might hide. Although robots in "Star Wars" and "Star Trek" do some very human things, our robots of today are a long way from being able to do those things. Most don't look very human -- and, in fact, many people would find a fully human-looking robot to be a creepy device.
There are internet robots that have no physical body, but are simply programs that do certain types of tasks. Usually they browse through the web looking for information and retrieving it for their owner. "Web spiders" (used by the search engine companies" are a type of web robot (called "bot" or "webbot") that search web pages, index them, and bring back the results to the search engine (like Google or Yahoo.) Other, more controversial ones, are software agents that do "bid sniping" on Ebay.
http://en.wikipedia.org/wiki/Internet_bot
It's useful to know about other types of robots, because classroom discussions may bring them up. For further reading on robot basics, see Wikipedia: http://en.wikipedia.org/wiki/Robot
Wikipedia is not entirely correct about the history of robotic things. The oldest story of something we might call a robot comes from ancient Sumeria (around 5,000 years ago or so); the story of a child of stone that grew so huge it threatened to shake the skies down.
The most basic definition of robotics (that everyone agrees upon) is that it is a science that uses technology to design and make machines that do very specific tasks -- and which can also react to the environment in some way.
The line between what we call a robot varies from culture to culture (Japan's definition is a bit differen than ours) -- and the forms that the robots take are different from ours as well. Most robots today are used to make cars and appliances, or to work in some areas of nuclear plants and chemical plants where it woule be too dangerous for a human. The military and police also use robots to defuse bombs and to look into places where they think snipers might hide. Although robots in "Star Wars" and "Star Trek" do some very human things, our robots of today are a long way from being able to do those things. Most don't look very human -- and, in fact, many people would find a fully human-looking robot to be a creepy device.
There are internet robots that have no physical body, but are simply programs that do certain types of tasks. Usually they browse through the web looking for information and retrieving it for their owner. "Web spiders" (used by the search engine companies" are a type of web robot (called "bot" or "webbot") that search web pages, index them, and bring back the results to the search engine (like Google or Yahoo.) Other, more controversial ones, are software agents that do "bid sniping" on Ebay.
http://en.wikipedia.org/wiki/Internet_bot
It's useful to know about other types of robots, because classroom discussions may bring them up. For further reading on robot basics, see Wikipedia: http://en.wikipedia.org/wiki/Robot
Wikipedia is not entirely correct about the history of robotic things. The oldest story of something we might call a robot comes from ancient Sumeria (around 5,000 years ago or so); the story of a child of stone that grew so huge it threatened to shake the skies down.
Wednesday, June 20, 2007
Absorption
This week I'm teaching a group of pre-schoolers a unit on absorption and water. It seems like a very simple idea (and the lesson plan is simple) -- we all know what absorption is. As I started outlining for myself the general information I wanted to give, I hit a real stumper:
"what's the mechanism for absorption and how do you explain it to a pack of 4 year olds?"
Uh.....
I knew what absorption IS, of course -- but how does it work? Internet turned out to be less help than I thought it would be. Dictionaries informed me that absorbency was "the property of being absorbant" (great. A circular definition. Everyone's favorite.) Absorbant was "the ability to absorb" (I was beginning to be suspicious at this point). "Absorb" means to "suck up" or "take up". I wasn't sucking up much knowledge from that.
The other dictionaries and encyclopedias were equally unhelpful. There's a boatload of tests for absorption, but no good explaination. After reading a number of articles, I eventually tracked down the answer -- an answer that's both interesting and surprising:
"what's the mechanism for absorption and how do you explain it to a pack of 4 year olds?"
Uh.....
I knew what absorption IS, of course -- but how does it work? Internet turned out to be less help than I thought it would be. Dictionaries informed me that absorbency was "the property of being absorbant" (great. A circular definition. Everyone's favorite.) Absorbant was "the ability to absorb" (I was beginning to be suspicious at this point). "Absorb" means to "suck up" or "take up". I wasn't sucking up much knowledge from that.
The other dictionaries and encyclopedias were equally unhelpful. There's a boatload of tests for absorption, but no good explaination. After reading a number of articles, I eventually tracked down the answer -- an answer that's both interesting and surprising:
The surprising answer is that water is sticky.
That's right -- it' s sticky. That answer seemed contrary to me until I explored it more thoroughly.
Stickiness is a physical property of things (ball bearings, for instance, are not sticky but the grease they're covered with is sticky. In the case of water, it's explained by a property called "cohesion" -- the electromagnetic forces that bond molecule to molecule. Because water molecules like to stick to each other (to "hold hands", as someone said) and water tends to "hang out" in globs and drops.
Think about it this way: sticky things stick to other things. If you put a metal spoon into a basket of beads, none of the beads stick to the spoon. Beads aren't sticky. If you put it into a cup of salt, salt won't stick to the metal because salt's not sticky. But if you put it into honey, when you pull it out there's honey on the spoon... honey's sticky. Oil sticks to the spoon.
So does water. We don't think of it as a sticky material because we use it to clean surfaces. But its stickiness... its tendency to "hold hands" with itself and with other substances gives water its most important properties: the ability to "wet" things and the ability to "soak into" things. It "slides into" small spaces and hangs around there (being very friendly), and adds to the weight of the object.
A good article on this is: http://www.exploratorium.edu/ronh/bubbles/sticky_water.html
Scholastic has a very nice little article for parents with some activities that will work for teachers or for curious adults who can't resist the chance to play with some sponges (that would be me!)
http://www.scholastic.com/earlylearner/age4/learning/sponges.htm
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