OCCRA
Go to Post Everything is possible. Some things are just harder to do than others. - vigkvagkv2 [more]
Home
Go Back   Chief Delphi > Technical > Programming
CD-Events   CD-Media   CD-Spy   FRC-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rate Thread Display Modes
  #1   Spotlight this post!  
Unread 05-26-2010, 04:07 PM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Finding Distance From Driver Station

Right now I'm playing with an idea for finding position based on the time it takes for a wlan message to take a round trip.

My goal is to do it in such a way that it would be legal, most specifically with R58.

The goal is to ping both the OPERATOR CONSOLE and the Field Management System. By knowing the position of both of those, and the distance from your robot to each you should be able to estimate your position.

I was wondering if anyone has any idea how to ping the OC or the FMS.

I am hoping that if this proves to be successful, that beacons (access points) could be put on the field, such that it could be more accurate. Similar to 2004 but using the wlan technology.


Quote:
<R58> One KOP wireless bridge (either model WGA600N or WET610N) is the only permitted mechanism for communicating to and from the ROBOT during the MATCH. The signal output from the wireless bridge must be directly connected to Port 1 of the cRIO-FRC with an Ethernet cable. All signals must originate from the OPERATOR CONSOLE and/or the Field Management System, and be transmitted to the ROBOT via the official ARENA hardware. No other form of wireless communications shall be used to communicate to, from or within the ROBOT (e.g. radio modems from previous FIRST competitions and Bluetooth devices are not permitted on the ROBOT during competition).
__________________
"Never let your schooling interfere with your education" -Mark Twain
  #2   Spotlight this post!  
Unread 05-26-2010, 04:12 PM
Vikesrock's Avatar
Vikesrock Vikesrock is offline
Team 2175 Founder
AKA: Kevin O'Connor
no team
Team Role: Engineer
 
Join Date: Mar 2006
Rookie Year: 2007
Location: Manchester, NH
Posts: 3,305
Vikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond reputeVikesrock has a reputation beyond repute
Send a message via AIM to Vikesrock Send a message via MSN to Vikesrock Send a message via Yahoo to Vikesrock
Re: Finding Distance From Driver Station

Before you go very far with this try something:

Figure out how long it would take an electromagnetic wave to travel from one corner of the field to the other. I believe you will find that it is a tiny fraction of the total ping time you would observe.
__________________


2007 Wisconsin Regional Highest Rookie Seed & Regional Finalists (Thanks 930 & 2039)
2008 MN Regional Semifinalists (Thanks 2472 & 1756)
2009 Northstar Regional Semifinalists (Thanks 171 & 525)
  #3   Spotlight this post!  
Unread 05-26-2010, 04:40 PM
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
Itinerant Programmer
AKA: Hey dad...Father...MARK
FRC #0358 (Robotic Eagles)
Team Role: Engineer
 
Join Date: Mar 2003
Rookie Year: 2002
Location: Hauppauge, Long Island, NY
Posts: 7,454
Mark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond repute
Re: Finding Distance From Driver Station

I don't follow what useful data you are looking to collect.

Are you looking for the latency of the robot's wireless bridge to FMS Access Point to derive the robot's distance from the AP?
Sounds like a step towards Zigbee triangulation...

All the rest of the communications are over a wired network with near-identical lengths of Ethernet cable, regardless of the Driver Station physical location. They'll all be at identical (wired) distance from the field Access Point, so I don't see that data as being useful.
It seems like any single ping (FMS or DS) would produce the same information, i.e. distance to AP or maybe length of the field Ethernet cables, speed of the network switches, frequency of collisions if you stretch it...
Assuming network collisions and retransmitted TCP/IP packets don't mess up your timings entirely...
__________________
The mind sees only what the mind is prepared to comprehend - Henri Bergson
358 Beta notes & results

Last edited by Mark McLeod : 05-26-2010 at 05:08 PM.
  #4   Spotlight this post!  
Unread 05-26-2010, 05:57 PM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by Vikesrock View Post
Before you go very far with this try something:

Figure out how long it would take an electromagnetic wave to travel from one corner of the field to the other. I believe you will find that it is a tiny fraction of the total ping time you would observe.
http://www.tkn.tu-berlin.de/publicat..._16_paper3.pdf

Using this technique they were able to get accuracy within 4m.
Not great, but it would be something.
Also if you had multiple APs to reference you could probably get more accurate by looking at their overlaps. It would eliminate some outliers.
Also based on what area in you could look for points of reference, bumps field borders, tunnels that kinda stuff.

This is only a proof of concept, as Mark pointed out the ideal solution would be to use zigbee which is much more accurate. I would also like to see robots use zigbee for robot to robot comms.

Quote:
Originally Posted by Mark McLeod View Post
Are you looking for the latency of the robot's wireless bridge to FMS Access Point to derive the robot's distance from the AP?
Sounds like a step towards Zigbee triangulation...
Zigbee is definitely what I want, I am hoping that if this even sort of works, that it will strengthen the argument to allow us to use zigbee devices on the robots.

And yes I would like to use the latency to estimate the robots position. I think it could give me enough accuracy to estimate what zone it is in, which is all I would need for localization. Even as bad as a 4m radius would still help, ie knowing roughly what heading to point to robot to see a target.
__________________
"Never let your schooling interfere with your education" -Mark Twain
  #5   Spotlight this post!  
Unread 05-26-2010, 06:10 PM
Dave Flowerday Dave Flowerday is offline
Software Engineer
VRC #0111 (Wildstang)
Team Role: Engineer
 
Join Date: Feb 2002
Rookie Year: 1995
Location: North Barrington, IL
Posts: 1,352
Dave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond reputeDave Flowerday has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by lineskier View Post
http://www.tkn.tu-berlin.de/publicat..._16_paper3.pdf

Using this technique they were able to get accuracy within 4m.
Not great, but it would be something.
In that paper, they were directly manipulating the WLAN card to send and receive raw WLAN frames, not IP layer pings. In FRC you do not have such control over the access point or the WLAN radio on the robot, so the method they employed would not be possible. Also, even with their method (that you can't reproduce), they achieve 4m accuracy, which is 1/4 of the length of the field or 1/2 of the width, so even at that (unobtainable) accuracy it doesn't seem very useful.

Also keep in mind that this method only gives you a distance, but not a direction, so even if it worked you would only be able to locate your robot along a circle across the field that would be drawn by using that distance as the radius of the circle. And to further complicate things, the access point used at the field is not located in a pre-defined position, and will vary between events and possibly even during the day of an event if it gets moved a bit by field personnel.
  #6   Spotlight this post!  
Unread 05-26-2010, 06:20 PM
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
Itinerant Programmer
AKA: Hey dad...Father...MARK
FRC #0358 (Robotic Eagles)
Team Role: Engineer
 
Join Date: Mar 2003
Rookie Year: 2002
Location: Hauppauge, Long Island, NY
Posts: 7,454
Mark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond repute
Re: Finding Distance From Driver Station

It'd be kind of interesting. You'd only be able to derive the radius of an arc from the field AP from this method. Probably a distance of 10 to 60 feet, so even with a best error of +/-12 feet it won't place you in one of this year's zones.

You'd only want to ping the AP (an 10.0.0.x address) if you can to eliminate other network latency from throwing off your results. For your tests at home pinging your wireless router at 10.xx.yy.4. That'll be a nice experiment that you don't have to confine to the dimensions of an FRC field.
__________________
The mind sees only what the mind is prepared to comprehend - Henri Bergson
358 Beta notes & results

Last edited by Mark McLeod : 05-27-2010 at 09:23 AM. Reason: unjumble sentence
  #7   Spotlight this post!  
Unread 05-26-2010, 06:30 PM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Re: Finding Distance From Driver Station

I guess my goal of trying to do it without breaking any rules isn't going to work.

Also I would be trying it with multiple access points, and this phase would just be to get the architecture in place for this kind of triangulation. I don't want to do it via WLAN, but the cRIO zigbee module is $700, and I don't have $2100 kicking around to produce a zigbee triangulation set up, as much as I would love to (anyone have grant money to do such a spike?? haha). Maybe I'll purchase some zigbee chips and try it that way. http://www.trossenrobotics.com/biolo...x?feed=Froogle ($25 a sensor)

http://ieeexplore.ieee.org/stamp/sta...umber=04463608

Thanks for all the feedback everyone!

(Hence why I switched from EE to CS )
__________________
"Never let your schooling interfere with your education" -Mark Twain

Last edited by lineskier : 05-26-2010 at 06:34 PM.
  #8   Spotlight this post!  
Unread 05-26-2010, 09:53 PM
RyanCahoon's Avatar
RyanCahoon RyanCahoon is offline
Compulsive frobnicator
FRC #0766 (M-A Bears)
Team Role: Leadership
 
Join Date: Dec 2007
Rookie Year: 2007
Location: Pittsburgh->Mountain View
Posts: 582
RyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond repute
Re: Finding Distance From Driver Station

I don't think this qualifies as thread-jacking as I think it still applies...

What about putting a beacon light on your driver station and using the camera to locate it? If you talked to your alliance partners and got the teams at stations 1 and 3 to each have a light, you could triangulate position using two cameras.

--Ryan
__________________
--Ryan

FRC 2046, 2007-2008, Student member
FRC 1708, 2009-2012, College mentor; 2013-2014, Mentor
FRC 766, 2014-, Mentor
  #9   Spotlight this post!  
Unread 05-26-2010, 10:18 PM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by RyanCahoon View Post
I don't think this qualifies as thread-jacking as I think it still applies...

What about putting a beacon light on your driver station and using the camera to locate it? If you talked to your alliance partners and got the teams at stations 1 and 3 to each have a light, you could triangulate position using two cameras.

--Ryan
Think we could use the beacons that already exist??

The red vs blue would be real nice cause you could look at either side.

Good idea!
__________________
"Never let your schooling interfere with your education" -Mark Twain
  #10   Spotlight this post!  
Unread 05-26-2010, 11:41 PM
davidthefat davidthefat is offline
Alumni
AKA: David Yoon
FRC #0589 (Falkons)
Team Role: Alumni
 
Join Date: Jan 2011
Rookie Year: 2010
Location: California
Posts: 792
davidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud ofdavidthefat has much to be proud of
Re: Finding Distance From Driver Station

Why not just software localization? Just keep track of where you are through software
__________________
Do not say what can or cannot be done, but, instead, say what must be done for the task at hand must be accomplished.
  #11   Spotlight this post!  
Unread 05-27-2010, 12:33 AM
RyanCahoon's Avatar
RyanCahoon RyanCahoon is offline
Compulsive frobnicator
FRC #0766 (M-A Bears)
Team Role: Leadership
 
Join Date: Dec 2007
Rookie Year: 2007
Location: Pittsburgh->Mountain View
Posts: 582
RyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond reputeRyanCahoon has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by lineskier View Post
Think we could use the beacons that already exist??

The red vs blue would be real nice cause you could look at either side.
Ooh... Sounds like I have a new offseason project

Good idea, yourself

Quote:
Originally Posted by davidthefat View Post
Why not just software localization? Just keep track of where you are through software
Maybe I don't understand what you're suggesting; you would be using software to detect the position of the lights from the camera images and triangulate your position.

If you're suggesting (the fairly standard method of) dead-reckoning using encoders/accelerometers/gyros, the advantage to the methods talked about in this thread is that you can determine absolute position on the field, whereas relative localization has accumulated error since at each point in time you're only calculating the change in position, so successive errors in the sensor readings lead to increasing errors in the position estimate.

--Ryan
__________________
--Ryan

FRC 2046, 2007-2008, Student member
FRC 1708, 2009-2012, College mentor; 2013-2014, Mentor
FRC 766, 2014-, Mentor
  #12   Spotlight this post!  
Unread 05-27-2010, 02:13 AM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by davidthefat View Post
Why not just software localization? Just keep track of where you are through software
Take this years game for instance, all sort of disorientation would occur when you cross the bump. So by having a absolute reference, you could re-initialize your position based on that reference. At that point you could switch to a sensor-driven localization similar to what your suggesting.

It kind of like zeroing a gyro based on a compass when you suspect drift.
__________________
"Never let your schooling interfere with your education" -Mark Twain
  #13   Spotlight this post!  
Unread 06-02-2010, 08:28 PM
DonRotolo's Avatar
DonRotolo DonRotolo is offline
Feeling Honorable
FRC #1676 (Pascack PI Oneers)
Team Role: Mentor
 
Join Date: Jan 2005
Rookie Year: 2005
Location: Montvale NJ
Posts: 6,510
DonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond reputeDonRotolo has a reputation beyond repute
Re: Finding Distance From Driver Station

Thinking in a different direction: If you were on the field, how would you find your location?

If it were me, I'd just look around, find objects I recognize, and estimate the distance to two or three of them by their relative size in my field of vision.

Turning that into a machine function, you can have your camera rotate until it finds your home driver station wall (this assumes you are able to see it). Hand each of your alliance partners a battery-powered flashing LED, each with a different blink pattern. Your camera sees the blinks, knows which one is where, and calculates location based on separation between LEDs (how close or far apart they are) and angle based on camera rotation.

Sure, there's a few issues to address. For example, what to do when you're up against the driver station wall. Perhaps four Maxbotix distance sensors can help there. Whatever, these issues can be solved.

The point is, consider how nature does this, and emulate. Nature usually has a pretty good algorithm.
__________________

I am N2IRZ - What's your callsign?
  #14   Spotlight this post!  
Unread 06-02-2010, 09:49 PM
lineskier's Avatar
lineskier lineskier is offline
Registered User
AKA: mike
FRC #0319 (Big Bad Bob)
Team Role: Mentor
 
Join Date: Feb 2005
Rookie Year: 2003
Location: Alton, New Shire
Posts: 680
lineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond reputelineskier has a reputation beyond repute
Re: Finding Distance From Driver Station

Quote:
Originally Posted by Don Rotolo View Post
Turning that into a machine function, you can have your camera rotate until it finds your home driver station wall (this assumes you are able to see it). Hand each of your alliance partners a battery-powered flashing LED, each with a different blink pattern. Your camera sees the blinks, knows which one is where, and calculates location based on separation between LEDs (how close or far apart they are) and angle based on camera rotation.
This was the idea behind looking at the driver station lights.
Also these lights are on either side, so you would just have to look to one side or the other, thus it wouldn't be side dependent. By seeing all 3 beacons in one scan you could tell where you were.

I think its relatively the same idea.
__________________
"Never let your schooling interfere with your education" -Mark Twain
  #15   Spotlight this post!  
Unread 06-03-2010, 11:42 AM
548swimmer's Avatar
548swimmer 548swimmer is offline
CAD Leader
AKA: Alec Wagner
FRC #0548 (Robostangs)
Team Role: CAD
 
Join Date: Apr 2010
Rookie Year: 2005
Location: Michigan
Posts: 304
548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of548swimmer has much to be proud of
Re: Finding Distance From Driver Station

Have you considered trying a sonar sensor to find your distance?
That might not have a narrow enough beam though.
__________________
My religion is physics, it can explain everything.

WINNER -- 2011 Waterford District
District Chairman's -- 2011 Waterford District
Finalist -- 2011 Ann Arbor District
State Chairman's -- 2011 Michigan State Championship
Quarter-finalist -- 2011 Galileo
2011 Championship -- Highest Ranking Score
Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Digital I/O from driver station vs FirstTouch I/O Module meakerb FRC Control System 4 03-05-2010 11:06 PM
using digital inputs from the driver station SL8 NI LabVIEW 2 02-04-2009 03:53 PM
Programming Digital Inputs from Driver Station spooncwru Programming 8 02-01-2009 01:14 PM
LabVIEW - Analog inputs from driver station lag? RedOctober45 NI LabVIEW 1 01-30-2009 10:39 AM
Problem Downloading Program from WindRiver to Driver Station The_Laughing_ManMII WindRiver C++ 10 01-09-2009 08:03 PM


All times are GMT -5. The time now is 10:45 AM.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi