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Swampdude 12-10-2005 15:25

Kit item request for 2006
 
As far as sensors go, I think most people would agree that a couple rotary encoders would be a great addition. Maybe a couple pots as well. I'm not sure what the success rate of the Hall effect sensors were, but I personally didn't see many teams "successfully" using feedback during autonomous. I think pots and encoders would be much easier and much more useful as far as autonomous navigation goes.
I personally doubt we'll see the banners or CMU's (I hope) again. I also haven't seen too many people use the accelerometers or gyro's when we had them. But every year I've wanted pots and encoders just as a basic need. Sure we could go buy whatever, but I think FIRST would save money by getting rid of the halls, accelerometers and especially the CMU. Then give us something useful like pots and encoders (preferably optical with good resolution). Although seeing as how the registrtion didn't get cheaper, there's still a costly gizmo likely to be coming like the CMU but hopefully not. What say you?

BrianBSL 12-10-2005 15:40

Re: Kit item request for 2006
 
With the exception of the CMU Cam, I believe most of the sensors (banners, gyro, hall effect) were donated or given to FIRST for next to nothing. If we got ADXRS300EB's in the kit as gyro's, or a sparkfun IMU board, I think you might find more teams using them.

I've actually found some interesting uses for the Banners, but nothing you couldn't do with a $5 part instead of the $50 the Banner's cost...but they were "free" so why not.

I don't see why pot's aren't included in the kit - perhaps because they are so cheap as COTS parts. My vote is for a good set of optical, high speed (ball bearing), medium count per rev (high enough for good resolution, but low enough to not flood the RC with interrupts) rotary encoders and a high quality gyro.

Holtzman 12-10-2005 16:07

Re: Kit item request for 2006
 
One sensor that I would like to see in the Kit of parts is an ultra sonic range finder. You could use it to measure the distance from the player station wall, or the distance to some other field features, and it wouldn't depend on wheel slip like optical encoders or hall effect sensors would. They would give you a certain degree of absolute positioning on the field, and not depend on perfect starting orientation.

They're not nearly as expensive as I would have expected either. Hobby Engineering has a selection of these sensors, and a number of other goodies on their website.
Check it out.
http://www.hobbyengineering.com/Sect...l?src=overture

BrianBSL 12-10-2005 16:20

Re: Kit item request for 2006
 
Quote:

Originally Posted by Holtzman
One sensor that I would like to see in the Kit of parts is an ultra sonic range finder. You could use it to measure the distance from the player station wall, or the distance to some other field features, and it wouldn't depend on wheel slip like optical encoders or hall effect sensors would. They would give you a certain degree of absolute positioning on the field, and not depend on perfect starting orientation.

They're not nearly as expensive as I would have expected either. Hobby Engineering has a selection of these sensors, and a number of other goodies on their website.
Check it out.
http://www.hobbyengineering.com/Sect...l?src=overture

We used the SRF04 in 2004 to measure the distance to the stairs. It worked pretty well - but if you are not pointing at what you think you are pointing at, then the reading is useless. They also are not the most durable device, and you can't completely enclose it like a gyro or accelerometer.

JamesBrown 12-10-2005 16:44

Re: Kit item request for 2006
 
I was thinking, VEX sensors are coming out and appear to be easy to use, they may not be the most accurate but they would be a solid alternative to counting loops.

Is there any reason why they wouldnt work?

John Gutmann 12-10-2005 17:36

Re: Kit item request for 2006
 
Quote:

Originally Posted by Holtzman
One sensor that I would like to see in the Kit of parts is an ultra sonic range finder. You could use it to measure the distance from the player station wall, or the distance to some other field features, and it wouldn't depend on wheel slip like optical encoders or hall effect sensors would. They would give you a certain degree of absolute positioning on the field, and not depend on perfect starting orientation.

They're not nearly as expensive as I would have expected either. Hobby Engineering has a selection of these sensors, and a number of other goodies on their website.
Check it out.
http://www.hobbyengineering.com/Sect...l?src=overture

you can use some thing like a mouse(optical or ball)

jdiwnab 12-10-2005 18:27

Re: Kit item request for 2006
 
Quote:

Originally Posted by sparksandtabs
you can use some thing like a mouse(optical or ball)

Robotic mice...you have to navigate though a program and avoid physical obsticals, using your robot at the mouse.... Sorry about the interruption, but that was just sweet.

Tom Bottiglieri 12-10-2005 19:56

Re: Kit item request for 2006
 
I would love to see out of the kit support for drive motor feedback. This be can be in the form of encoders, hall effect sensors, or some other form of technology (Back EMF :)). I would love to see 2 encoders in every kit with premade mounting equipment to the output shafts on the transmissions.

While this modification isn't extremely hard to handle on your own, out the the box support for motor feedback might make autonomous mode alot easier and more reliable for lots of teams.

Andrew Rudolph 14-10-2005 21:42

Re: Kit item request for 2006
 
I remember many years ago FIRST gave us Pots. Its one of thoes useful things that is difficult to find well made ones, and they used to give us good quality ones.

Kims Robot 15-10-2005 08:54

Re: Kit item request for 2006
 
I think any sensors FIRST can provide (personally I would check all of the above) are great to get teams thinking on their feet. While a lot of people had trouble with the CMUcam, I think it was a great learning device, and something that they can spend plenty of time on in the preseason. It didnt take us long to have it following a color target around, but we had to recruit new programmers with 2 weeks left, and had decided to focus on the other autonomous modes.

As an electrical engineer, all of the sensors fascinate me. We tried to get an ultrasonic sensor onto our robot last year, but didnt have enough robot or code space. We will likely try and plan for it this year.

Mike 15-10-2005 14:14

Re: Kit item request for 2006
 
I'd like to see some kind of radar system. Something similar to http://www.ri.cmu.edu/pubs/pub_561.html
Quote:

This thesis research presents the design and evaluation of an integrated sensor system for obstacle detection and collision avoidance for automobile vehicles and mobile robot outdoor navigation.
...
Clutter rejection and the ability to classify and differentiate between objects in different road lanes and off-road is improved by integration of the radar data with information from a road geometry perception system. Road geometry perception is based on either of two systems: the first one detects road lane markers or other features parallel to the road through a video camera and thereby computes vehicle position and orientation with respect to the current driving lane; the second system uses a digital road map in combination with a GPS and heading gyroscope unit to compute vehicle location and orientation on the road. Finally, we discuss the performance results obtained for both systems.
It sounds pretty hard, but this is FIRST =D

Billfred 15-10-2005 17:05

Re: Kit item request for 2006
 
I'm going to second the call for good pots. We got some pots from RadioShack to control our bubble maker instead of using a joystick, but they were so glitchy that it wasn't even funny.

On the other hand, gyros and encoders wouldn't be too bad to have in the kit either.

Andrew Schuetze 12-11-2005 08:31

Re: Kit item request for 2006
 
Quote:

Originally Posted by Tom Bottiglieri
I would love to see out of the kit support for drive motor feedback. This be can be in the form of encoders, hall effect sensors, or some other form of technology (Back EMF :)).
While this modification isn't extremely hard to handle on your own, out the the box support for motor feedback might make autonomous mode alot easier and more reliable for lots of teams.

Okay, I just saw a robot application of this using Lego system motors yesterday. Charmed labs has created a new interface (Gameboy based) for Botball that uses back emf and reportedly has precision down to 10,000 cpr.

Is back emf possible using the victor speed controllers? Using the FRC 2005 system, would we need to add in a voltage sensing circuit between the motor and victor?

Mostly curious as we will attempt to add non-driven encoder wheels to help with autonomous this year.
:cool:

Okay, I just found a lot more on this topic in this thread
http://www.chiefdelphi.com/forums/sh...d.php?p=386117

sorry :o

Bill_Hancoc 12-11-2005 15:04

Re: Kit item request for 2006
 
Quote:

Originally Posted by sparksandtabs
you can use some thing like a mouse(optical or ball)

We thought of doing that and had plans to utilize one and were testing different mice until I realized, if you move the mouse forward it reads a forward movement; if you move the mouse backward it reads a backward movement; unless you have an omni bot which contiunssly has the same NSEW orientation to the field it wont work. ie If you go forward then turn the mouse 90 deg right adn then go forward again the mouse will still register forward movement. It doesnt reconize rotation.

lukevanoort 13-11-2005 14:46

Re: Kit item request for 2006
 
Quote:

Originally Posted by Bill_Hancoc
We thought of doing that and had plans to utilize one and were testing different mice until I realized, if you move the mouse forward it reads a forward movement; if you move the mouse backward it reads a backward movement; unless you have an omni bot which contiunssly has the same NSEW orientation to the field it wont work. ie If you go forward then turn the mouse 90 deg right adn then go forward again the mouse will still register forward movement. It doesnt reconize rotation.

What if you had two mice, one for each side. When you turn one registers backward movement, and the other forward. We did this with encoders on a couple kit wheels on the sides, so wheelspin didn't affect them. Those were really heavy though (~two pounds a side), mice would be much lighter (writes email).


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