DL1 datalogger questions
03-05-2005, 08:49 AM
#31
Rennlist Member
Dr. GPS, any idea how long your DL90 for DL1 discounted trade in program will be in effect? I have a DL90 and would like to upgrade but just haven't prioritized the change yet in my track budget...
03-05-2005, 11:59 AM
#32
Addict
Rennlist Member
Rennlist Member
Originally Posted by Eric86Red911
I used the DL1 last summer and agree with the above comments that you can in fact see the lines you take. But I didn't find this to be helpful; i mean, what do you do with that? I know what line I should be taking, and that often I miss it, causing slow exit speeds. So I don't think analyzing my lines helps that any.
When you are down to small time increments, often times you cannot tell one line is faster than another. A lap timer alone does you no ultimate good because you don't know where you did it right. THIS is were Acq is most effective. It gives you the luxury of trying every wacky line you can think of and then getting a direct comparison of whether it actually worked or not, quite apart from the driver's perception, which can often be wrong.
03-05-2005, 01:03 PM
#33
Lifetime Rennlist Member
I really question the value of an accurate map of your line, via GPS. Now I have never used a GPS system, so it is just my guess, but here goes.
1) If you can not run consistent laps, within a couple tenths of each other, then how can you tell if subtle line changes are making any difference or if it is inconsistency? If it is major line changes, then you don't need GPS to see that - just watch the fast guys.
If you are looking for seconds and half seconds in sections of the lap, then a coach will help get that. At that level, I doubt that experimenting with different lines is the answer. Rather it is just learning to drive the car closer to the edge.
2) If you can run at that higher level, then you are likely experienced enough to make changes in the line, know what change you made and then look at lap and segment times to see what was faster. Now I can see how GPS might be a help with this - simply to help you remember what lap you tired what line. Video will work much better for that, IMO so what does GPS really do for you.
3) At our levels, you simply can not take two different drivers (let alone two different cars), overlay data and learn anything about the line. You CAN learn a great deal about braking points, throttle, turn in techniques, balance, etc - as long as you have the right data. BUT, if you have .3 seconds difference in skills/consistency between 2 drivers, you can't possibly understand how a slightly different line contributes to that. The faster driver could be on a slightly worse line but be much faster because they are using all the car.
Now, do that with F1 level drivers who you know are all driving at the limit, and you can learn something.
Finally, back to the start. If a driver is not able to turn consistent laps, then what does any data mean? It will be far, far less than with a consistent driver. So since I have no personal experience with GPS, can anyone cite how it has really helped them? Now I have no problem with people who gather data and play with it. I do that with a lot of my data. I have yet to actually be able to use shock data to help tune the car. All I can do is see strange patterns when I know the car sucked, but I can't look at data and determine what to change. In that sense, it is just fun data. Is GPS just 'fun' data, or is it really useful.
1) If you can not run consistent laps, within a couple tenths of each other, then how can you tell if subtle line changes are making any difference or if it is inconsistency? If it is major line changes, then you don't need GPS to see that - just watch the fast guys.
If you are looking for seconds and half seconds in sections of the lap, then a coach will help get that. At that level, I doubt that experimenting with different lines is the answer. Rather it is just learning to drive the car closer to the edge.
2) If you can run at that higher level, then you are likely experienced enough to make changes in the line, know what change you made and then look at lap and segment times to see what was faster. Now I can see how GPS might be a help with this - simply to help you remember what lap you tired what line. Video will work much better for that, IMO so what does GPS really do for you.
3) At our levels, you simply can not take two different drivers (let alone two different cars), overlay data and learn anything about the line. You CAN learn a great deal about braking points, throttle, turn in techniques, balance, etc - as long as you have the right data. BUT, if you have .3 seconds difference in skills/consistency between 2 drivers, you can't possibly understand how a slightly different line contributes to that. The faster driver could be on a slightly worse line but be much faster because they are using all the car.
Now, do that with F1 level drivers who you know are all driving at the limit, and you can learn something.
Finally, back to the start. If a driver is not able to turn consistent laps, then what does any data mean? It will be far, far less than with a consistent driver. So since I have no personal experience with GPS, can anyone cite how it has really helped them? Now I have no problem with people who gather data and play with it. I do that with a lot of my data. I have yet to actually be able to use shock data to help tune the car. All I can do is see strange patterns when I know the car sucked, but I can't look at data and determine what to change. In that sense, it is just fun data. Is GPS just 'fun' data, or is it really useful.
03-05-2005, 03:12 PM
#34
Instructor
Thread Starter
Join Date: Apr 2002
Location: Caledon East Ontario
Posts: 159
Likes: 0
Received 0 Likes
on
0 Posts
Need some help with sensors,
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
They recommend them for suspension, however my concern is that the rate of recoil may not be as fast as the rate of compression experienced during bump.
Does anyone have a source for the linear potentionometers similar to the ones race technology sells? I believe I have also seen the shaft body style in the pits on some GT3 RS cars. Also, my preference would be to measure actual damper travel, any ideas for mounting to a leda damper?
Thanks,
Andrew
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
They recommend them for suspension, however my concern is that the rate of recoil may not be as fast as the rate of compression experienced during bump.
Does anyone have a source for the linear potentionometers similar to the ones race technology sells? I believe I have also seen the shaft body style in the pits on some GT3 RS cars. Also, my preference would be to measure actual damper travel, any ideas for mounting to a leda damper?
Thanks,
Andrew
03-05-2005, 04:57 PM
#35
Originally Posted by Andrew Wojteczko
Need some help with sensors,
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
The UniMeasure stuff is US manufacture, right?
There are numerous other US sources.
- Advantage
- Pi Research
...and more
Race Technology, AIM, Stack & MoTeC all have good sensor product lines, of course.
03-05-2005, 05:02 PM
#36
Lifetime Rennlist Member
Originally Posted by Andrew Wojteczko
Need some help with sensors,
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
They recommend them for suspension, however my concern is that the rate of recoil may not be as fast as the rate of compression experienced during bump.
Does anyone have a source for the linear potentionometers similar to the ones race technology sells? I believe I have also seen the shaft body style in the pits on some GT3 RS cars. Also, my preference would be to measure actual damper travel, any ideas for mounting to a leda damper?
Thanks,
Andrew
I am trying to locate sensors in the US or Canada to use to measure damper position. Has anyone used the recoiling string style for damper position, as seen here http://www.unimeasure.com/initinfo.htm
They recommend them for suspension, however my concern is that the rate of recoil may not be as fast as the rate of compression experienced during bump.
Does anyone have a source for the linear potentionometers similar to the ones race technology sells? I believe I have also seen the shaft body style in the pits on some GT3 RS cars. Also, my preference would be to measure actual damper travel, any ideas for mounting to a leda damper?
Thanks,
Andrew
Veracity Data
03-05-2005, 08:10 PM
#37
Addict
Rennlist Member
Rennlist Member
Join Date: Dec 2001
Location: MA
Posts: 1,010
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by SundayDriver
So since I have no personal experience with GPS, can anyone cite how it has really helped them? Now I have no problem with people who gather data and play with it. I do that with a lot of my data. I have yet to actually be able to use shock data to help tune the car. All I can do is see strange patterns when I know the car sucked, but I can't look at data and determine what to change. In that sense, it is just fun data. Is GPS just 'fun' data, or is it really useful.
I believe the addition of the AIM GPS option allows for 3-D track mapping which might add some data that was of some interest or at least put some of the G data in finer perspective. Useful? Well, I'm sure it's good for impressing the pit babes!
03-05-2005, 08:31 PM
#38
Burning Brakes
Join Date: Nov 2001
Location: Jupiter
Posts: 1,093
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by SundayDriver
I really question the value of an accurate map of your line, via GPS. Now I have never used a GPS system, so it is just my guess, but here goes...
If you compare segment times on two different laps then you can see which is faster in those segments. You can then look at the details to figure out why one lap is faster than the other. Is it segment entry speed (suggesting the exit speed from the previous corner might have been faster)? Is it the braking point? Is it the turn-in point? Is it the point where the driver gets back into the power? Is it that the driver is not braking as much? And so on.
You mention that one driver might just be pushing harder than another but this should be obvious as he will be performing better in all segments and not just one or two.
Your G-sum calculation will find the driver who is pushing harder everywhere but it is not useful for analysing why one driver is faster than another. And as I’ve said before, this is why I think looking at G-sum information is only about as useful as lap times.
Lap times alone are also not sufficient because they do not tell you about specific segments. I could be faster on certain parts of the track than you but lose time elsewhere. The lap time would be similar. Yet if you looked at specific segments then you still might learn something useful.
Ideally, you would compare two laps from two different drivers with similar lap times. If you see an improvement in a specific segment then you know that he is doing something better in that corner. Then you figure out what he is doing better.
Lastly, one big advantage of looking at segments is that a driver need not push hard for the entire lap. He might need to deal with traffic on part of a lap and yet the remaining data will still be useful. If you looked at lap times or G-sum figures then the whole lap would be ruined. At the Nürburgring this is important because the laps are long and a driver is almost certainly going to have to deal with traffic at some point during the lap.
So the process is to divide the track into segment, identify segments where one driver is faster than another and then analyse specifically what a driver is doing in a segment to make them faster. Video information alone is not accurate enough for this. Driver feel is not accurate enough either.
Stephen
03-06-2005, 08:35 AM
#39
Nordschleife Master
I currently have a DL90 and the thing I like about the GPS is the accuracy of the track map. While I've never used it to compare line, it does give you a sense of what is happening at a given point on the track. I would also agree that video overlay is probably even better for this purpose.
03-06-2005, 10:31 AM
#40
Lifetime Rennlist Member
Originally Posted by FixedWing
I think you’ve answered your own question. It is all about segment times.
If you compare segment times on two different laps then you can see which is faster in those segments. You can then look at the details to figure out why one lap is faster than the other. Is it segment entry speed (suggesting the exit speed from the previous corner might have been faster)? Is it the braking point? Is it the turn-in point? Is it the point where the driver gets back into the power? Is it that the driver is not braking as much? And so on.
You mention that one driver might just be pushing harder than another but this should be obvious as he will be performing better in all segments and not just one or two.
Your G-sum calculation will find the driver who is pushing harder everywhere but it is not useful for analysing why one driver is faster than another. And as I’ve said before, this is why I think looking at G-sum information is only about as useful as lap times.
Lap times alone are also not sufficient because they do not tell you about specific segments. I could be faster on certain parts of the track than you but lose time elsewhere. The lap time would be similar. Yet if you looked at specific segments then you still might learn something useful.
Ideally, you would compare two laps from two different drivers with similar lap times. If you see an improvement in a specific segment then you know that he is doing something better in that corner. Then you figure out what he is doing better.
Lastly, one big advantage of looking at segments is that a driver need not push hard for the entire lap. He might need to deal with traffic on part of a lap and yet the remaining data will still be useful. If you looked at lap times or G-sum figures then the whole lap would be ruined. At the Nürburgring this is important because the laps are long and a driver is almost certainly going to have to deal with traffic at some point during the lap.
So the process is to divide the track into segment, identify segments where one driver is faster than another and then analyse specifically what a driver is doing in a segment to make them faster. Video information alone is not accurate enough for this. Driver feel is not accurate enough either.
Stephen
If you compare segment times on two different laps then you can see which is faster in those segments. You can then look at the details to figure out why one lap is faster than the other. Is it segment entry speed (suggesting the exit speed from the previous corner might have been faster)? Is it the braking point? Is it the turn-in point? Is it the point where the driver gets back into the power? Is it that the driver is not braking as much? And so on.
You mention that one driver might just be pushing harder than another but this should be obvious as he will be performing better in all segments and not just one or two.
Your G-sum calculation will find the driver who is pushing harder everywhere but it is not useful for analysing why one driver is faster than another. And as I’ve said before, this is why I think looking at G-sum information is only about as useful as lap times.
Lap times alone are also not sufficient because they do not tell you about specific segments. I could be faster on certain parts of the track than you but lose time elsewhere. The lap time would be similar. Yet if you looked at specific segments then you still might learn something useful.
Ideally, you would compare two laps from two different drivers with similar lap times. If you see an improvement in a specific segment then you know that he is doing something better in that corner. Then you figure out what he is doing better.
Lastly, one big advantage of looking at segments is that a driver need not push hard for the entire lap. He might need to deal with traffic on part of a lap and yet the remaining data will still be useful. If you looked at lap times or G-sum figures then the whole lap would be ruined. At the Nürburgring this is important because the laps are long and a driver is almost certainly going to have to deal with traffic at some point during the lap.
So the process is to divide the track into segment, identify segments where one driver is faster than another and then analyse specifically what a driver is doing in a segment to make them faster. Video information alone is not accurate enough for this. Driver feel is not accurate enough either.
Stephen
BTW - as far as G-Sum, I am still interested in any evidence that it has value. I have run a few years worth of my own data through it and reached my own conclusion, based on hard data. When comparing laps or segments that are very different in time (say 2-4 seconds per lap) then it agrees with lap times and segement times. When you start analyzing laps or segments that are within tenths, it fails. There is no correlation. Even when it works, I fail to see why it has any value in the real world. I can read lap and segment times directly and that is what counts. G-Sum is a less than accurate estimator of lap times. What is the point?
03-06-2005, 10:35 AM
#41
Lifetime Rennlist Member
How accurate is the lap timer with GPS. I saw the earlier post, but my data does not support the idea that beacon and loop times vary becasue of the size of the field or width of the beam. I think in both cases, you get the time when you enter the beam or field. I almost always get beacon based times that agree wihin 2-3 thousandths of a second with the AMB loop times. Anyone have GPS based times in an event that also has AMB times? If so, how well do they agree?
BTW - I do agree and like the idea that for DE's and other casual environment, not needing a beacon is a great feature. I am just wondering how effective that time is when you care about small fractions of a second. Do GPS based lap times use the clock internal to the DA system or do they grab times from the GPS signal?
BTW - I do agree and like the idea that for DE's and other casual environment, not needing a beacon is a great feature. I am just wondering how effective that time is when you care about small fractions of a second. Do GPS based lap times use the clock internal to the DA system or do they grab times from the GPS signal?
03-06-2005, 03:15 PM
#42
3rd Gear
Join Date: Mar 2005
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Hi SundayDriver et al,
The information I related about accuracy of lap times from optical system comes our own experimentation and our customers experience - but please note I was quoting the *worst* case... of course most the time it is far far better, I was simply making the point that you could not be guaranteed 0.01 second accuracy from either GPS or optical beacons.
GPS has huge advantages - both in terms of track mapping and just as importantly high accuracy speed measurements and that is why *all* DA manufactures I'm aware of are now in the process of integrating it into there own systems - indeed we work with a number of other manufacturers with their own GPS products. However it should be added, whilst as an engineer I "like" GPS for its technical advantages, it is fair to say *most* our customers simply prefer the convenience, and the improved accuracy is just a bonus.
A couple of other points that have come up....
1/ 3D track mapping is a nice idea, but in practice the errors in the vertical axis are twice the horizonal errors so unless you are looking for big changes the data is of limited value. That said, our "next generation" fully differential system will also include altitude but this has a much higher base accuracy.
2/ We will continue to offer upgrades from DL90 to DL1 indefinitely, and we have no plans to stop supporting the DL90 in future software upgrades.
...I hope I have helped a little?! I'm not going to be posting anymore - I don't feel entirely comfitable as this forum isn't the place for me to be promoting our own products, there are rules on the subject I'm sure!! If you do have any questions about GPS, or DA in general then you can of course email us directly and we would be delighted to help.
Many thanks, and happy (safe) racing!
Andy
The information I related about accuracy of lap times from optical system comes our own experimentation and our customers experience - but please note I was quoting the *worst* case... of course most the time it is far far better, I was simply making the point that you could not be guaranteed 0.01 second accuracy from either GPS or optical beacons.
GPS has huge advantages - both in terms of track mapping and just as importantly high accuracy speed measurements and that is why *all* DA manufactures I'm aware of are now in the process of integrating it into there own systems - indeed we work with a number of other manufacturers with their own GPS products. However it should be added, whilst as an engineer I "like" GPS for its technical advantages, it is fair to say *most* our customers simply prefer the convenience, and the improved accuracy is just a bonus.
A couple of other points that have come up....
1/ 3D track mapping is a nice idea, but in practice the errors in the vertical axis are twice the horizonal errors so unless you are looking for big changes the data is of limited value. That said, our "next generation" fully differential system will also include altitude but this has a much higher base accuracy.
2/ We will continue to offer upgrades from DL90 to DL1 indefinitely, and we have no plans to stop supporting the DL90 in future software upgrades.
...I hope I have helped a little?! I'm not going to be posting anymore - I don't feel entirely comfitable as this forum isn't the place for me to be promoting our own products, there are rules on the subject I'm sure!! If you do have any questions about GPS, or DA in general then you can of course email us directly and we would be delighted to help.
Many thanks, and happy (safe) racing!
Andy
03-07-2005, 05:33 AM
#43
Advanced
Join Date: Aug 2003
Location: Norway
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
I for one would really like that you'd stay onboard Andy. There's a good chance that your answer to someone else will be of a topic that interests me too. And there are plenty of other vendors here that are managing to balance their posts to avoid direct advertising.
Folks, is there anything that prohibits a vendor/manufacturer from participating? As long as it's not direct advertising, I would not think so.
Cheers,
Ørjan
Folks, is there anything that prohibits a vendor/manufacturer from participating? As long as it's not direct advertising, I would not think so.
Cheers,
Ørjan
Last edited by Orjan; 03-07-2005 at 05:51 AM.
03-07-2005, 09:46 AM
#44
Lifetime Rennlist Member
Originally Posted by Orjan
I for one would really like that you'd stay onboard Andy. There's a good chance that your answer to someone else will be of a topic that interests me too. And there are plenty of other vendors here that are managing to balance their posts to avoid direct advertising.
Folks, is there anything that prohibits a vendor/manufacturer from participating? As long as it's not direct advertising, I would not think so.
Cheers,
Ørjan
Folks, is there anything that prohibits a vendor/manufacturer from participating? As long as it's not direct advertising, I would not think so.
Cheers,
Ørjan
03-07-2005, 11:38 AM
#45
Andy has a wealth of real-world knowledge, and lots of testing to back it up. It would be terrific to have this contribution to the board. Just looking at the number of threads on data analysis over the past few months shows that this is an active topic. Having someone with strong credentials to clarify questions on technology, resolution and the like would be a real asset.
If Andy has the time, his participation should be welcomed.
If Andy has the time, his participation should be welcomed.