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Damiaen_Florian 29-10-2014 13:24

Fastest FRC Robot?
 
I couldn't find a thread post anywhere discussing this so I was wondering, to the best of everyone's knowledge, what was the fastest robot in FRC History? If you're aware of the robots FPS or any other interesting features about their drivetrain then please feel free to list them, thanks!

My current guess would be 148 in 2008 but I'm not entirely sure.

thatprogrammer 29-10-2014 15:10

Re: Fastest FRC Robot?
 
Team 102 was capable of going 27 fps in 2008, of course, they couldn't actually reach that speed on the FRC field.

Mk.32 29-10-2014 16:59

Re: Fastest FRC Robot?
 
254 in 2011? Was underweight and geared for 21FPS? If i remember.

AdamHeard 29-10-2014 17:13

Re: Fastest FRC Robot?
 
Our minibot on a horizontal surface ;)

Mike Marandola 29-10-2014 17:28

Re: Fastest FRC Robot?
 
Citrus Circuits were geared for 22 fps this year.

donkehote 30-10-2014 12:39

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by thatprogrammer (Post 1406315)
Team 102 was capable of going 27 fps in 2008, of course, they couldn't actually reach that speed on the FRC field.

My old now defunct team was geared and could hit 28 fps in 08. A 25 lb robot before batteries helps that a lot. 7 second laps for the win. Unfortunately, due to internal team politics, our team never went to competition with that robot.

Tyler2517 30-10-2014 12:53

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by donkehote (Post 1406476)
My old now defunct team was geared and could hit 28 fps in 08. A 25 lb robot before batteries helps that a lot. 7 second laps for the win. Unfortunately, due to internal team politics, our team never went to competition with that robot.

I do not think i have the mental capability to drive something with that much acceleration.

donkehote 30-10-2014 13:27

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Tyler2517 (Post 1406479)
I do not think i have the mental capability to drive something with that much acceleration.

It was surprisingly easy to drive. It had a double stacked omni on the front to turn. We drove forward on the small wheels, and turned when we rotated the wheel. we originally had Ackerman steering, but it never returned to center 100%. Using the omni, straight was straight. The rear axle was solid, but turning lifted the inside wheel, just like in a go-kart, so drag losses while turning were limited. It was a lot of fun to drive.

Caleb Sykes 30-10-2014 13:53

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by donkehote (Post 1406483)
It was surprisingly easy to drive. It had a double stacked omni on the front to turn. We drove forward on the small wheels, and turned when we rotated the wheel. we originally had Ackerman steering, but it never returned to center 100%. Using the omni, straight was straight. The rear axle was solid, but turning lifted the inside wheel, just like in a go-kart, so drag losses while turning were limited. It was a lot of fun to drive.

Did you incorporate any sensor feedback (e.g. gyros, encoders) to help the driver?

RoboChair 30-10-2014 14:11

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Mike Marandola (Post 1406334)
Citrus Circuits were geared for 22 fps this year.

There is Geared and Actual FPS. We only could hit 17-18 FPS on field(we measured this). Our 22 FPS was our theoretical top speed.

I vote that this thread reports Actual FPS as measured on the field, not what the gearbox was "capable" of.

donkehote 30-10-2014 14:44

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by inkling16 (Post 1406489)
Did you incorporate any sensor feedback (e.g. gyros, encoders) to help the driver?

We only had an array of ping sensors looking forward, and to the sides for auto.
it drove laps autonomously in auto with obstructions, but again, it never made it to comp, so I never got to see how well that would have worked in real competition.

Michael Hill 30-10-2014 17:49

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by RoboChair (Post 1406494)
There is Geared and Actual FPS. We only could hit 17-18 FPS on field(we measured this). Our 22 FPS was our theoretical top speed.

I vote that this thread reports Actual FPS as measured on the field, not what the gearbox was "capable" of.


I've always been annoyed when people say "Geared for [XX]". Is that according to the JVN spreadsheet? or is that actually measured? Simulated another way?

Ether 30-10-2014 18:16

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Michael Hill (Post 1406508)
Is that according to the JVN spreadsheet?

And if so, what value did you use for the "speed loss constant" fudge factor?



AdamHeard 30-10-2014 18:18

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Michael Hill (Post 1406508)
I've always been annoyed when people say "Geared for [XX]". Is that according to the JVN spreadsheet? or is that actually measured? Simulated another way?

When teams are comparing theoretical speeds, I think it makes sense to sense to use "geared for" assuming that means free speed. This way frictional estimates don't affect the number. This is essentially the rollout ratio times a CIMs free speed.

Any other number I think is only valid if actually measured, or from a team that has measured several of their similar drives and has decent enough friction parameters to estimate future drives.

Ether 30-10-2014 18:21

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by AdamHeard (Post 1406510)
Any other number I think is only valid if actually measured, or from a team that has measured several of their similar drives and has decent enough friction parameters to estimate future drives.

Quoted for truth.



Lil' Lavery 31-10-2014 07:17

Re: Fastest FRC Robot?
 
Without any standardized benchmarks to test completed drivetrains, I have no problem with "geared to" comparisons. It's still the most useful shorthand to compare different drive speeds.

Michael Hill 31-10-2014 10:41

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Lil' Lavery (Post 1406572)
Without any standardized benchmarks to test completed drivetrains, I have no problem with "geared to" comparisons. It's still the most useful shorthand to compare different drive speeds.

The problem is robots that are "Geared to [x]" will not even theoretically reach that speed. If I say I geared my robot to 25 ft/s, it will never reach close to that. In fact, if I say I geared my robot to 20 ft/s, it will actually go faster than the one "geared" to 25 ft/s. A more useful metric would be something like "it goes covers 20 feet in 2 seconds from a stop". That's something that's actually somewhat easily measurable and useful.

Chris is me 31-10-2014 12:31

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Michael Hill (Post 1406597)
The problem is robots that are "Geared to [x]" will not even theoretically reach that speed. If I say I geared my robot to 25 ft/s, it will never reach close to that. In fact, if I say I geared my robot to 20 ft/s, it will actually go faster than the one "geared" to 25 ft/s. A more useful metric would be something like "it goes covers 20 feet in 2 seconds from a stop". That's something that's actually somewhat easily measurable and useful.

The value of everyone using free speed to talk about gearing isn't in being able to literally use the number as is to know the robot's top speed. The problem with using adjusted speed is that everyone uses different constants and parameters to define what their adjusted free speed is. Geared free speed puts everyone on the same page, and the reader can apply their own constants to adjust that free speed if they so choose. It's just a known benchmark that's easiest for everyone to agree on in order to compare robots to each other.

AdamHeard 31-10-2014 12:49

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Michael Hill (Post 1406597)
The problem is robots that are "Geared to [x]" will not even theoretically reach that speed. If I say I geared my robot to 25 ft/s, it will never reach close to that. In fact, if I say I geared my robot to 20 ft/s, it will actually go faster than the one "geared" to 25 ft/s. A more useful metric would be something like "it goes covers 20 feet in 2 seconds from a stop". That's something that's actually somewhat easily measurable and useful.

No one disagrees with the point you're making about robots not hitting their free speed.

The point others are making is that in absence of good data on friction, teams should report free speed as that is a more clear comparison to others.

TLDR; I'd rather have someones idealized (frictionless) numbers than their BS guess at friction.

Mr. Lim 31-10-2014 13:08

Re: Fastest FRC Robot?
 
Fastest means something quite different on our team:

How long does it take to travel X ft from a standing stop?

Where X depends on the game as each one has a different typical "sprint" length.

I don't think we've geared for a specific top speed in a long time.

As a result, we probably have some of the "slowest" robots in FRC...:confused:

ErvinI 31-10-2014 13:46

Re: Fastest FRC Robot?
 
Quote:

Originally Posted by Mr. Lim (Post 1406629)
Fastest means something quite different on our team:

How long does it take to travel X ft from a standing stop?

Where X depends on the game as each one has a different typical "sprint" length.

I don't think we've geared for a specific top speed in a long time.

As a result, we probably have some of the "slowest" robots in FRC...:confused:

To be fair, if all teams reported this measurement, then all robots would be the "fastest" robots, however they would all be the "fastest" for different sprint lengths.

That being said, I would be surprised if the highest top speed of a robot was not one of the sprint bots of '08. Those little fellas looked nigh-uncontrollable.

Caleb Sykes 31-10-2014 15:16

Re: Fastest FRC Robot?
 
I think I remember playing with a team last year who told me their robot was geared for 26fps. I am also pretty sure that they only had a single speed transmission.

What I definitely remember was how long it took them to travel short distances. Frankly, I was not impressed.

Their reasoning was that, even though they knew they would never reach this speed, that the increased acceleration from this arrangement would be beneficial. Unfortunately, I didn't get a chance to explain to them why their reasoning was flawed. What I should have done is asked them why, by that reasoning, they didn't gear their robot for 100fps.


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