Assuming your sensors reliably detect your magnetic tape, it may be as simple as using existing line-following code for QTI (optical) sensors, and there are plenty of examples extant. What's more difficult is finessing the particulars of your situation, since there are so many variables: chassis size & weight, wheel grip/power/speed, type of steering (Ackerman/differential), chassis geometry, sensor type, number & location. Do you have your bot, tape, and sensors already? The more info you provide, the quicker you'll get useful info here.
I already used QTR sensor, but the robot is big and the lights are very high...the robot is lost in the shadows that causes.
I have magnetic tape, and i just need to create a magnetic sensor. I read MGS1600S, its a very expensive. . .i need to create a sensor like QTR, but magnetic. . .understand? The everything rest works , i just need the ''eye sensor''. I have 6 sensores A1302, but i think thats sensor its not very sensible. I need options :frown:
Help me
I already used QTR sensor, but the robot is big and the lights are very high...the robot is lost in the shadows that causes.
I have magnetic tape, and i just need to create a magnetic sensor. I read MGS1600S, its a very expensive. . .i need to create a sensor like QTR, but magnetic. . .understand? The everything rest works , i just need the ''eye sensor''. I have 6 sensores A1302, but i think thats sensor its not very sensible. I need options :frown:
Help me
Asking the obvious,
What MicroController are you using?
What is the width of the magnetic tape?
What is the size of the vehicle?
The A1302 may work, but it depends on how close to the ground.
What kind of surface?
I'm using de Arduino Uno
The magnetic tape have 25mm
The robot have 40cm x 60cm
The surface of the ground is shifting. . . has parts which is cement, other cement that is varnished.
Have you tried any Hall-effect sensors with the magnetic tape? I'd think the magnetic field from the tape would be very weak. I think it would be much easier to fix your IR sensors than to use magnetic tape.
One problem people often have with line following robots is the tape they are using doesn't absorb IR well. Electrical tape doesn't always work. Parallax sells black masking tape which works well at absorbing IR.
IR sensor its not possible, because the ground floor can be dark or white, its irregular.
The manetic tap , I'm using the tapes that are used in classroom board
I'll need to let someone else help here. I haven't done this sort of thing before.
It might help if someone else if you give a link to the type of tape you're referring to. Is it the kind of tape one uses to make ornamental magnets? Or is it magnetic tape used to record video or music?
IR sensor its not possible, because the ground floor can be dark or white, its irregular.
The manetic tap , I'm using the tapes that are used in classroom board
Actually, IR could be best. There are two properties at play, one is IR reflection, one is IR absorption. Some floor surfaces reflect, some absorb. Same with the tape.
If you make a reflective line, and border it with a pair of absorptive lines, you should have a uniform path over ANY floor surface. So you can use IR for the cost of an additional roll of tape.
There might be a reason many folks use IR and few use magnetic tape.
Actually, IR could be best. There are two properties at play, one is IR reflection, one is IR absorption. Some floor surfaces reflect, some absorb. Same with the tape.
If you make a reflective line, and border it with a pair of absorptive lines, you should have a uniform path over ANY floor surface. So you can use IR for the cost of an additional roll of tape.
There might be a reason many folks use IR and few use magnetic tape.
IIRC Jessica's S2 line following demo used used a light colored tape on Parallax's dark carpet.
If the robot knew which area it was in, it could switch between looking for reflective tape or looking for absorbing tape. I think prof_braino's idea of using three stripes is better though.
If you could shield the tape and sensors from sunlight, you'd probably get better results. Maybe some sort of disc around the sensor would be a enough to block the ambient light?
I'd be concerned the magnetic tape would damaged from people walking on it.
The magnetic tape might be worth experimenting with. I hope you share your results with us if you do.
After reading your suggestions, and see the limit of material I have available, tomorrow i try one thing.
Place one 25mm white tape up 100mm black tape. . .
what do you thing. probably work or not?
And put the leds together my IR sensors, its a good idea?
After reading your suggestions, and see the limit of material I have available, tomorrow i try one thing.
Place one 25mm white tape up 100mm black tape. . .
what do you thing. probably work or not?
And put the leds together my IR sensors, its a good idea?
I use QTR-8A, its a good sensors?
It sounds good to me. I don't have a lot of experience with line following robots but I do know what looks white or black to our eyes might not look that way to the sensor. I think you should test a variety of tapes to see which work the best.
I don't know if I've used the QTR-8A but from what I've read they seem like they're a good sensor.
We (chibots.org) use everything and anything. The same tape from the same manufacturer could be different between batches. Some work anywhere, some have trouble in sunlight, some have trouble in flourescent light. Test them all, under each likely lighting condition.
As Duane says, it would be best if you could rig a portable version of you sensor and light source, and test at the store.
Also, If you put the sensor UNDER the bot, so its always in shadow, you can eliminate much (but not all) of the effect of ambient light.
If anyone can help you out, this guy can. Nathan uses magnetic tape and IR sensors to drive a fleet of autonomous LEGO vehicles. The video doesn't show the underside, but I know Nathan and have personally seen the underside of these boards which contain the magnetic strip tape. The IR is used for collision detection and avoidance of other vehicles. Specialized sections of the track also allow for charging.
Comments
I have the same problem. . .i nedd to using a magnetic tape and hall efect sensors.
You already have a solution?
Tell me which sensor you use. . .pleaseeeeeeeeeeeeee
I have magnetic tape, and i just need to create a magnetic sensor. I read MGS1600S, its a very expensive. . .i need to create a sensor like QTR, but magnetic. . .understand?
The everything rest works , i just need the ''eye sensor''. I have 6 sensores A1302, but i think thats sensor its not very sensible. I need options :frown:
Help me
Asking the obvious,
What MicroController are you using?
What is the width of the magnetic tape?
What is the size of the vehicle?
The A1302 may work, but it depends on how close to the ground.
What kind of surface?
The magnetic tape have 25mm
The robot have 40cm x 60cm
The surface of the ground is shifting. . . has parts which is cement, other cement that is varnished.
One problem people often have with line following robots is the tape they are using doesn't absorb IR well. Electrical tape doesn't always work. Parallax sells black masking tape which works well at absorbing IR.
The manetic tap , I'm using the tapes that are used in classroom board
It might help if someone else if you give a link to the type of tape you're referring to. Is it the kind of tape one uses to make ornamental magnets? Or is it magnetic tape used to record video or music?
I think that should work well with a Hall-Effect sensor. You might need to worry about the continually changing north south bands.
Phil used the changing bands as an encoder here. Maybe you'll find some useful information in Phil's thread.
That's the only example I can think of someone using that kind of tape.
Actually, IR could be best. There are two properties at play, one is IR reflection, one is IR absorption. Some floor surfaces reflect, some absorb. Same with the tape.
If you make a reflective line, and border it with a pair of absorptive lines, you should have a uniform path over ANY floor surface. So you can use IR for the cost of an additional roll of tape.
There might be a reason many folks use IR and few use magnetic tape.
IIRC Jessica's S2 line following demo used used a light colored tape on Parallax's dark carpet.
If the robot knew which area it was in, it could switch between looking for reflective tape or looking for absorbing tape. I think prof_braino's idea of using three stripes is better though.
If you could shield the tape and sensors from sunlight, you'd probably get better results. Maybe some sort of disc around the sensor would be a enough to block the ambient light?
I'd be concerned the magnetic tape would damaged from people walking on it.
The magnetic tape might be worth experimenting with. I hope you share your results with us if you do.
After reading your suggestions, and see the limit of material I have available, tomorrow i try one thing.
Place one 25mm white tape up 100mm black tape. . .
what do you thing. probably work or not?
And put the leds together my IR sensors, its a good idea?
I use QTR-8A, its a good sensors?
It sounds good to me. I don't have a lot of experience with line following robots but I do know what looks white or black to our eyes might not look that way to the sensor. I think you should test a variety of tapes to see which work the best.
I don't know if I've used the QTR-8A but from what I've read they seem like they're a good sensor.
Thanks for everything. . .tomorrow i comeback with news :cool:
The tape I linked to in post #10 is all I've used.
It would be nice if you could make your sensor portable and test the various tapes at the store without having to buy them first.
FIRST check if the tape is reflective or absorptive IN IR!!!!!!!
Black could reflect IR, white could absorb IR. Black eletrical tape and black Duct tape are both different in IR, at least the ones I have.
Since you can't see IR you shouldn't assume a material looks the same in visible light and IR.
As Duane says, it would be best if you could rig a portable version of you sensor and light source, and test at the store.
Also, If you put the sensor UNDER the bot, so its always in shadow, you can eliminate much (but not all) of the effect of ambient light.
http://okrobotics.com/
http://www.youtube.com/watch?v=eo9sAHwrr6Y
http://www.youtube.com/watch?v=VyzYfBkwRsc