NXT letter recognition

[Katarn]

Hi guys!

I've been following this forum for a couple of weeks now, and you guys seem amazing!

I am trying to build an nxt robot and was wondering if you guys could help me with some issues I am having. I have a fair bit of experience with the nxt, having done 4 years of robotics competitions with it, but now I am venturing into more advanced stuff using RobotC and other programming languages. Basically, what I want to build is a device that will use the light sensor to scan a letter that a person has written and then determine if that letter would be legible to a human. It is meant as a theoretical device that could teach handwriting to children that have trouble interacting with humans. It doesn't even have to recognize a word, just a single letter! I have already built the scanner and have had success using it to display the scanned letter on the nxt screen. My problem is that I don't know how to make a machine that can point at a letter and say "that is an 'a' and this letter is a 'c'" My first question is whether this is even possible with the nxt, and if so, how would I go about doing it?

Any help would be appreciated. thanks!

[JopieK]

Well, with the normal sensors that is not going to work. You will need a much more accurate one or write with a marker and very large.

[Mud]

This NXT su doku robot managed it

[chorlton]

Hi guys!

I've been following this forum for a couple of weeks now, and you guys seem amazing!

I am trying to build an nxt robot and was wondering if you guys could help me with some issues I am having. I have a fair bit of experience with the nxt, having done 4 years of robotics competitions with it, but now I am venturing into more advanced stuff using RobotC and other programming languages. Basically, what I want to build is a device that will use the light sensor to scan a letter that a person has written and then determine if that letter would be legible to a human. It is meant as a theoretical device that could teach handwriting to children that have trouble interacting with humans. It doesn't even have to recognize a word, just a single letter! I have already built the scanner and have had success using it to display the scanned letter on the nxt screen. My problem is that I don't know how to make a machine that can point at a letter and say "that is an 'a' and this letter is a 'c'" My first question is whether this is even possible with the nxt, and if so, how would I go about doing it?

Any help would be appreciated. thanks!

I can't find the link but remember reading about a neural-network implemented on a NXT brick. I think it was for a clap-counter. It's a complex topic but NNs can be used for character recognition.

I'm afraid I'm posting from a hotel with limited bandwidth so can't go find the links myself just now.

[Mud]

I can't find the link but remember reading about a neural-network implemented on a NXT brick. I think it was for a clap-counter. It's a complex topic but NNs can be used for character recognition.

I'm afraid I'm posting from a hotel with limited bandwidth so can't go find the links myself just now.

Perhaps cross correlation with reference characters would be more achievable....but would hinge on the handwriting being fairly well controlled: things like slanty handwriting and scaling could make the results poor. You can apply transforms to the kernel, but it'll quickly get complicated and the neural network will start looking more appealing (especially if someone's already written the code and you're just training it). If we're talking cursive, then that's a whole extra level of complication. Whatever approach you take, you'll probably have to do some de-noising, segmentation and dilation/erosion first.

I'm afraid I'm not far-enough along with the NXT to say what it can and can't do, but cross correlation is about as simple as it'll get!