Go to Post A dedicated team is a happy team. - sgreco [more]
Home
Go Back   Chief Delphi > Competition > Rules/Strategy
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
  #31   Spotlight this post!  
Unread 01-07-2008, 01:16 PM
WaterFreak WaterFreak is offline
Registered User
FRC #0708 (Hardwired Fusion)
Team Role: Mentor
 
Join Date: Feb 2007
Rookie Year: 2002
Location: Warrington, PA
Posts: 29
WaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to beholdWaterFreak is a splendid one to behold
Re: Top speed?

Quote:
Originally Posted by Bongle View Post
a perfectly efficient drivetrain and no resistance.
this is where is all goes awry, since that does not exist
__________________
Thanks, Jim Orr
Senior Software Engineer - Motorola, Connected Home
Supporting Team 708 - Hardwired Fusion
  #32   Spotlight this post!  
Unread 01-07-2008, 01:23 PM
Bongle's Avatar
Bongle Bongle is offline
Registered User
FRC #2702 (REBotics)
Team Role: Mentor
 
Join Date: Feb 2004
Rookie Year: 2002
Location: Waterloo
Posts: 1,016
Bongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond reputeBongle has a reputation beyond repute
Send a message via MSN to Bongle
Re: Top speed?

Quote:
Originally Posted by WaterFreak View Post
this is where is all goes awry, since that does not exist
Along with the need to draw more amps than our breakers provide, the ability to accelerate hard enough that your tires rather than your motors are the limiting factor, the ability to turn controllably without losing velocity, the assumption that nobody would get in your way while you lapped, etc. It was all just a thinking exercise to figure out the absolute fastest laptime possible. The next step would be to constrain it so that your power output is less than 120amps and see what happens then.

Last edited by Bongle : 01-07-2008 at 01:27 PM.
  #33   Spotlight this post!  
Unread 01-07-2008, 01:26 PM
Elgin Clock's Avatar
Elgin Clock Elgin Clock is offline
updates this status less than FB!
AKA: the one who "will break into your thoughts..."
FRC #0237 (Black Magic)
Team Role: Mentor
 
Join Date: May 2001
Rookie Year: 2001
Location: H20-Town, Connecticut
Posts: 7,754
Elgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond repute
Send a message via AIM to Elgin Clock
Re: Top speed?

Quote:
Originally Posted by Scott Carpman View Post
Good luck trying to turn with a 30 fps drivetrain...
It's all relative...

It all depends on what type of drive system you are going to be using I guess.
__________________
The influence of many leads to the individuality of one. - E.C.C. (That's me!!)

  #34   Spotlight this post!  
Unread 01-07-2008, 01:30 PM
bmather bmather is offline
Dr. Digital
AKA: Bruce
FRC #0499 (Toltechs)
Team Role: Mentor
 
Join Date: Dec 2007
Rookie Year: 2004
Location: San Antonio, Texas
Posts: 1
bmather is an unknown quantity at this point
Re: Top speed?

There is no rule that specifically states that you must obey the law of physics during the competition. This may be an oversight.
  #35   Spotlight this post!  
Unread 01-07-2008, 01:39 PM
petek's Avatar
petek petek is offline
What would Dave do?
AKA: Peter Kieselbach
FRC #3654 (Tech Tigers)
Team Role: Mentor
 
Join Date: May 2002
Rookie Year: 2002
Location: Middletown, CT
Posts: 923
petek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond reputepetek has a reputation beyond repute
Send a message via AIM to petek
Re: Top speed?

Quote:
Originally Posted by bmather View Post
There is no rule that specifically states that you must obey the law of physics during the competition. This may be an oversight.
I believe that is covered by <General Rule 0>: the part about "...recognition of science..."
__________________
Pete Kieselbach
#4

  #36   Spotlight this post!  
Unread 01-07-2008, 01:40 PM
Rupnick's Avatar
Rupnick Rupnick is offline
Registered User
FRC #1675 (UPS - Ultimate Protection Squad)
Team Role: Mentor
 
Join Date: Oct 2007
Rookie Year: 2006
Location: Milwaukee, Wi
Posts: 47
Rupnick is on a distinguished road
Send a message via AIM to Rupnick
Re: Top speed?

last year we had a 16fps robot and if anyone was at the Milwaukee regional they would have seen our programming error where we went full forward for 2 secs and for got to put the stop in. Needles to say it was devistating we hit the far wall at full speed and thewheels just kept moving. Head ref estoped us and that was the end of that. It truly was a sight to see.

Last edited by Rupnick : 01-07-2008 at 01:43 PM.
  #37   Spotlight this post!  
Unread 01-07-2008, 01:47 PM
Dave Scheck's Avatar
Dave Scheck Dave Scheck is offline
Registered User
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Feb 2003
Rookie Year: 2002
Location: Arlington Heights, IL
Posts: 568
Dave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond reputeDave Scheck has a reputation beyond repute
Re: Top speed?

Quote:
Originally Posted by thefro526 View Post
(20 fps mecanum/holonomic/swerve).
This makes me chuckle a little bit. Last year, we had a 7fps crab system. Driving full forward and doing a 90 degree crab maneuver put a ton of stress on the drive modules. We cracked the hubs on quite a few wheels due to the tremendous side load. I can only imagine what would happen if the wheels of a robot moving 20fps were suddenly turned perpendicular to the direction of travel.
  #38   Spotlight this post!  
Unread 01-07-2008, 01:50 PM
Tom Line's Avatar
Tom Line Tom Line is offline
Raptors can't turn doorknobs.
FRC #1718 (The Fighting Pi)
Team Role: Mentor
 
Join Date: Jan 2007
Rookie Year: 1999
Location: Armada, Michigan
Posts: 2,070
Tom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond reputeTom Line has a reputation beyond repute
Re: Top speed?

I think you should consider that just like last year - in the absence of other robots you might be able to hang 10 or 11 tubes. When other robots are present, however, you are sometimes lucky to hang 3 or 4.

I would bet with slow movers on the course and having to dodge other robots, even disregarding hurdling and pushing balls, you'll average 8-10 second lap times.
  #39   Spotlight this post!  
Unread 01-07-2008, 01:51 PM
Koko Ed's Avatar
Koko Ed Koko Ed is offline
Serial Volunteer
AKA: Ed Patterson
FRC #0191 (X-Cats)
Team Role: Mentor
 
Join Date: Mar 2002
Rookie Year: 2002
Location: Rochester,NY
Posts: 21,696
Koko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond reputeKoko Ed has a reputation beyond repute
Re: Top speed?

As I remeber hearing once. I don't care about the car that goes 0-55 inn 2.5 seconds. I want the car that can go from 80 - 50 in 1.2 seconds. It's not gonna just be how fast you get around the straightaway but can you survive the hairpin turn.
__________________
  #40   Spotlight this post!  
Unread 01-07-2008, 02:01 PM
Jherbie53's Avatar
Jherbie53 Jherbie53 is offline
Hoshua The 2nd
AKA: Joshua aka "Hosh"
FRC #0085 (Built On Brains B.O.B.)
Team Role: College Student
 
Join Date: Mar 2005
Rookie Year: 2003
Location: Zeeland, MI
Posts: 363
Jherbie53 is a splendid one to beholdJherbie53 is a splendid one to beholdJherbie53 is a splendid one to beholdJherbie53 is a splendid one to beholdJherbie53 is a splendid one to beholdJherbie53 is a splendid one to beholdJherbie53 is a splendid one to behold
Send a message via Yahoo to Jherbie53
Re: Top speed?

Quote:
Originally Posted by Tom Line View Post
I would bet with slow movers on the course and having to dodge other robots, even disregarding hurdling and pushing balls, you'll average 8-10 second lap times.
I've been thinking. With a speed of 10fps it would take you about 5 seconds to travel the length of the field. Double that and add about 5 seconds overall turning time and you get a lap average of 15 seconds. This is of course without anything in your way.

If you did average 15 seconds a lap, the max number of laps you could do in two minutes is 8. Now if you started at the right spot, you can cross the finish line 9 times, scoring 18 points. This is even with traffic.

I'm not really expecting more than 5-7 laps for one robot in a match. No matter how fast you are going.
__________________
  #41   Spotlight this post!  
Unread 01-07-2008, 02:02 PM
abeD's Avatar
abeD abeD is offline
Registered User
FRC #4707 (Mentor FRC#4707 Alumni FRC#710)
Team Role: Mentor
 
Join Date: Sep 2003
Rookie Year: 2001
Location: Ft Lauderdale, FL
Posts: 305
abeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to beholdabeD is a splendid one to behold
Re: Top speed?

Going around this turn reminds me a lot of autonomous mode of 2003, some teams would steer (mine included) and some teams had tank but would have wheel lowered on an angle that would steer them around the corner then bring it up into the chasis (312 did this and a few others but I can't remember them now)
__________________
Penn Class 08
  #42   Spotlight this post!  
Unread 01-07-2008, 02:10 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: Top speed?

This is somewhat related to the topspeed discussion so I figure I'll ask it here. When determining the "top speed" of a robot in relation to it's gearing, wheels, motors, ect. what point on the motor curve are you taking the RPM numbers from? My team is a second year team with little or no help from any Mech E's and we are looking to do a bit more in terms of drivetrain design than we did last year.

So when someone says they have a 15fps or 16fps robot what RPM is that on the motor (assuming 2.5" CIM)?
__________________


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)
  #43   Spotlight this post!  
Unread 01-07-2008, 02:34 PM
RobJ RobJ is offline
Registered User
FRC #0254 (Cheesy Poofs)
Team Role: Teacher
 
Join Date: Jan 2007
Rookie Year: 2005
Location: San Jose
Posts: 34
RobJ is a glorious beacon of lightRobJ is a glorious beacon of lightRobJ is a glorious beacon of lightRobJ is a glorious beacon of lightRobJ is a glorious beacon of lightRobJ is a glorious beacon of light
Re: Top speed?

Quote:
Originally Posted by Vikesrock View Post
This is somewhat related to the topspeed discussion so I figure I'll ask it here. When determining the "top speed" of a robot in relation to it's gearing, wheels, motors, ect. what point on the motor curve are you taking the RPM numbers from? My team is a second year team with little or no help from any Mech E's and we are looking to do a bit more in terms of drivetrain design than we did last year.

So when someone says they have a 15fps or 16fps robot what RPM is that on the motor (assuming 2.5" CIM)?
It depends on the size of your wheel. If you go 16 fps with 8 inch wheels then your motors will be rotating twice as fast at 16 fps with 4 inch wheels
  #44   Spotlight this post!  
Unread 01-07-2008, 03:11 PM
Elgin Clock's Avatar
Elgin Clock Elgin Clock is offline
updates this status less than FB!
AKA: the one who "will break into your thoughts..."
FRC #0237 (Black Magic)
Team Role: Mentor
 
Join Date: May 2001
Rookie Year: 2001
Location: H20-Town, Connecticut
Posts: 7,754
Elgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond reputeElgin Clock has a reputation beyond repute
Send a message via AIM to Elgin Clock
Re: Top speed?

I can easily see teams doing laps under 10 seconds with a great line of travel, and no interference.

Whether or not this will happen is to be seen.

But it can, which to me is pretty darn awesome.
__________________
The influence of many leads to the individuality of one. - E.C.C. (That's me!!)

  #45   Spotlight this post!  
Unread 01-07-2008, 03:12 PM
lukevanoort lukevanoort is offline
in between teams
AKA: Luke Van Oort
no team
 
Join Date: Oct 2005
Rookie Year: 2005
Location: Waterloo, ON, Canada
Posts: 1,873
lukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond reputelukevanoort has a reputation beyond repute
Send a message via AIM to lukevanoort
Re: Top speed?

Quote:
Originally Posted by Vikesrock View Post
This is somewhat related to the topspeed discussion so I figure I'll ask it here. When determining the "top speed" of a robot in relation to it's gearing, wheels, motors, ect. what point on the motor curve are you taking the RPM numbers from? My team is a second year team with little or no help from any Mech E's and we are looking to do a bit more in terms of drivetrain design than we did last year.

So when someone says they have a 15fps or 16fps robot what RPM is that on the motor (assuming 2.5" CIM)?
It also depends on the team reporting that speed. Relatively few teams measure actual speed (I think the Martians do, but beyond that I can't think of anybody). So, then you get into theoretical calculations. Some teams approximate inefficiencies (JVN's famous .81% of free speed is an example), some just use the 12V free speed, and some report numbers based off of operation at 40A draw.

I wouldn't use the 40A one, because most of the time you aren't going to draw that much just driving around, and if you are you're probably in trouble. (40A per motor doesn't leave much wiggle room at all on either the motor breakers or the main breaker) Similarly, I highly doubt teams will be driving with their motors running at 12V free speed; however, there is something to be said for the argument that the battery doesn't output 12V, more like 13.5ish, and that can make up for some of the inefficiency losses. The approximation method may end up more accurate than either of the above, but that is obviously dependent on how accurate the inefficiency approximation itself is.

Personally, I just use free speed in calculations because it is easier to work with. In my experience, underestimating speed has worse consequences than overestimating (to many interrupts per sec, dead-reckoning autonomous driving too far, etc). Whatever you choose stick with one; you can then compare speeds year to year much easier than if you had to convert from one method to the other.
__________________
Team 1219: 2009 - Mentor
Team 587: 2005 - Animator, 2006-2008 - Team Captain
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
pic: Back-in-Black 4-speed Top View unclewaldo Extra Discussion 10 04-10-2013 11:40 PM
Letting robots on top vs getting on top of robots sanddrag Rules/Strategy 44 02-09-2007 09:50 AM
pic: Top Gun Top Wheels Rick TYler Robot Showcase 4 02-04-2006 10:13 AM
speed controller max speed Team 668 Programming 15 02-13-2005 01:05 PM
Top Speed Victim of Fate Technical Discussion 43 12-16-2003 09:10 PM


All times are GMT -5. The time now is 07:29 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