Autonomous Perception

[davidthefat]

Originally Posted by kamocat

Going back to the gamepieces, is the camera really the best way of finding them?
Could a robot have "whiskers" along the sides, so it could tell if it brushed up against a ball?
For now, I'm going to ignore how much IO each sensor (or set of sensors) might require.

I was going with the idea of using a technology that allows you to see any shape using the photon particles reflected from the object... And also sound waves... AKA a sonar and IR and a camera

[kamocat]

Originally Posted by davidthefat

I was going with the idea of using a technology that allows you to see any shape using the photon particles reflected from the object... And also sound waves... AKA a sonar and IR and a camera

Well, one of the factors I'm trying to work with is cost. I want to get the most out of what I spend.
If I line my robot with SONAR, that's $250 for only two per side.
If I use IR, it's still $120 for the same thing (though lower range, non-linear, and unknown view angle)
The camera has a view angle of +-15 degrees.

Please show me a diagram that demonstrates that 8 SONAR or 8 IR (plus the camera) are all I need to find a game piece anywhere around the 'bot. Feel free to demonstrate why they're the best solution.

[ideasrule]

I would suggest implementing autonomous with the minimum possible number of sensors. The camera seems very promising, but it's very hard to use, especially in real time. Does anybody have an idea of how to find a robot using the camera? How about a ball resting against a robot or wall?

[davidthefat]

Originally Posted by kamocat

Well, one of the factors I'm trying to work with is cost. I want to get the most out of what I spend.
If I line my robot with SONAR, that's $250 for only two per side.
If I use IR, it's still $120 for the same thing (though lower range, non-linear, and unknown view angle)
The camera has a view angle of +-15 degrees.

Please show me a diagram that demonstrates that 8 SONAR or 8 IR (plus the camera) are all I need to find a game piece anywhere around the 'bot. Feel free to demonstrate why they're the best solution.

I think you are over spending here, I was going to put 2 or 3 IR sensors on a servo, so it sweeps side to side, the sonar would be the general guideline and there only will be 1 on a servo that goes 360 degrees, if it detects something, the irs and camera turn that way to check up on it... Not sure if its the fastest, but that is a pretty cheap way to do it

[kamocat]

If the sensors are at the same height as the balls, won't the robot be in the way of seeing 360 degrees?
If they're on top of the robot, won't they be in the way of each other? How do you spot a gamepiece if it's right up against your 'bot?

[davidthefat]

Originally Posted by kamocat

If the sensors are at the same height as the balls, won't the robot be in the way of seeing 360 degrees?
If they're on top of the robot, won't they be in the way of each other? How do you spot a gamepiece if it's right up against your 'bot?

Who says it will be a ball? IDK I want to make it as generic as possible and add if I need more stuff, also the robots will be one of the things I want to track

[kamocat]

Oh, sorry, I misunderstood you.
I thought you were talking specifically about the game piece.
You're saying that these SONAR and IR will be an excellent method of tracking other robots?

[davidthefat]

Originally Posted by kamocat

Oh, sorry, I misunderstood you.
I thought you were talking specifically about the game piece.
You're saying that these SONAR and IR will be an excellent method of tracking other robots?

I would just use it to get a general sense of direction and the camer will get the color of the bumper

[kamocat]

Originally Posted by davidthefat

I would just use it to get a general sense of direction and the camer will get the color of the bumper

A general sense of direction for navigation?
Does that mean you would treat walls, bumps, towers, and gamepieces just as obstacles?
Or would you compare the data to where you are on the field, to determine what is a bump, what is a wall, what is a tower, and what must be something else?
Would these sonar and IR generally be angled down, or would they be straight out?

This sounds like an interesting method, and I'd love to see some working code for it. Would you be willing to do that and post your results?

[davidthefat]

Originally Posted by kamocat

A general sense of direction for navigation?
Does that mean you would treat walls, bumps, towers, and gamepieces just as obstacles?
Or would you compare the data to where you are on the field, to determine what is a bump, what is a wall, what is a tower, and what must be something else?
Would these sonar and IR generally be angled down, or would they be straight out?

This sounds like an interesting method, and I'd love to see some working code for it. Would you be willing to do that and post your results?

They will be angled down, but not too much. Its just theory right now, can't start since Im on spring break and I have not yet met with our group to actually start

[kamocat]

Well, when you're ready, Maxbotix makes some great SONAR.
http://www.maxbotix.com/Performance_Data.html

[Al3+]

Range finders are a good idea, but they're kind of limited. Unless you plan to have a whole row of them, you probably need a better way to distinguish between gamepieces, robots, and obstacles.

I imagine a possible "find gamepiece" routine going something like this:
Use the camera to find the nearest blob matching certain parameters (depending on gamepiece). If one exists, compute the angle from the x-position in the image, rotate the bot to that angle using gyro, confirm that the gamepiece is still there, then use a rangefinder on the front of the robot to find the distance and drive up to it. If none are found, rotate 30 degrees or so and try again.

[kamocat]

That sounds like a good routine for finding gamepieces.
However, I feel that the gimbals still limit the 'bot to dealing with one gamepiece at a time.

[Radical Pi]

Originally Posted by kamocat

That sounds like a good routine for finding gamepieces.
However, I feel that the gimbals still limit the 'bot to dealing with one gamepiece at a time.

And this is bad? If the bot is trying to deal with multiple balls at the same time, by the time it takes care of one ball there's a good chance the other ball it noticed isn't there any more, and will have to seek for it again anyways

[kamocat]

It depends whether your goal is to acquire the gamepiece, or to keep another 'bot away from them.
However, I would still argue that if you can keep track of multiple gamepieces around you at the same time, then you immediately know where to go when one is taken, and you don't waste time looking for another. I think gamepiece detection should be passive most of the time.
Also, by not using the camera for finding gamepieces, then the robot could focus on the target to fire, but still be aware of what's happening around it.

EDIT: I replaced all instances of "ball" with "gamepiece". Isn't there PHP for this?