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Matt - thanks for the post. I took Roger's seminar but we didn't get to do a lot of advanced work on math channels. I'm utilizing many of his examples but there is one type of channel I want to create that has me stumped, which is how to show the Vmin and Vmax values for the turns at a given track. In my case, I'm starting with Road Atlanta. I know how to calculate the distance function, but I'm not sure how to represent the rest of the calculation. In English, it would go something like this: Calculate the minimum GPS speed when the distance is between 500 and 1000 ft. Once I have one working example, I'd be happy to create all the variations and post them. Not sure if this is possible, or if I'm overlooking a simpler way to do this. I know you can get this info in many of the reports, but I want it represented in a math channel so I can quickly compare laps in the channels report.
I just PM'ed you the methodology and an example how to do it. I'll post up the finished product later tonight/tomorrow.
Here's a couple of visuals on the end results. There are two shots from Race Studio 2 and then one from Excel. RS2 always puts the channels reports in alphabetical order, so they don't end up in order. I exported that to Excel, then rearranged it and added some spark lines and the data coloring on the two columns.
It was probably 45 to set up the math channels for the corners (which included getting the distances from the data), doing the min/max channels, and setting up the channel report. The Excel part was about 5 minutes. This creates a nice report and is a great idea by rm21!
Matt - Really appreciate your help with this. It is exactly what I was looking for. I find it much better than the track report since that gets very busy when you display multiple laps. Here is my Road Atlanta report that I cleaned up in Excel. I sequenced the data so that the straights precede the turns. Wish I could get back on track after looking at this. So much opportunity!
BTW - You may have noticed there is a minor bug in the export routine. It replaces a couple of the values in the first row with asterisks. Easy enough to clean up manually.
I reposted the image since I mislabeled one of the columns in Excel. I also added some comparison data from my other car.
I own a 944 race car with an AIM MXL. My focus was to learn how to drive a momentum car, doing DE'S and then hiring procoaches to learn the nuances of level of braking and modulation, trail braking at turn in, earlier corner turn in then instructed in DE and looking foward as far as needed. The AIM was used for measure lap times to determine improvement.
Now I have plateaued and looking for utilizing the AIM system to look for opportunities. Peter Argetsinger, my coach, drove the 944 at Watkins Glen and the session was video recorded and car data was collected on the AIM.
I believe that I have found for me the most useful math channel to compare my best solo lap time with Peter's best lap time. The differential was 4 seconds but Peter was handicapped with my weight, giving up 20 equivalent HP.
The Radius of the corner comparison indexes when you turn in, how effective is your spiral to the apex, is it an early or late apex compared to the procoach,.etc.? For me gsum comparisons were not illuminating.
I now know where I turned in early or late, what was the efficacy spiral to the apex resulting in an early, apex, proper spex, or late apex. The video will provide the non-movable visible track markers for the efficacy turn in point and the data provides the brake efficacy point, ramp up and down or modulation and release point for trail braking.
I would be remiss if I did not give kudos to Peter Krause's SVRA DOP's teachable moments which I transferred to an 8 second lower lap time.
I own a 944 race car with an AIM MXL. My focus was to learn how to drive a momentum car, doing DE'S and then hiring procoaches to learn the nuances of level of braking and modulation, trail braking at turn in, earlier corner turn in then instructed in DE and looking foward as far as needed. The AIM was used for measure lap times to determine improvement.
Now I have plateaued and looking for utilizing the AIM system to look for opportunities. Peter Argetsinger, my coach, drove the 944 at Watkins Glen and the session was video recorded and car data was collected on the AIM.
I believe that I have found for me the most useful math channel to compare my best solo lap time with Peter's best lap time. The differential was 4 seconds but Peter was handicapped with my weight, giving up 20 equivalent HP.
The Radius of the corner comparison indexes when you turn in, how effective is your spiral to the apex, is it an early or late apex compared to the procoach,.etc.? For me gsum comparisons were not illuminating.
I now know where I turned in early or late, what was the efficacy spiral to the apex resulting in an early, apex, proper spex, or late apex. The video will provide the non-movable visible track markers for the efficacy turn in point and the data provides the brake efficacy point, ramp up and down or modulation and release point for trail braking.
I would be remiss if I did not give kudos to Peter Krause's SVRA DOP's teachable moments which I transferred to an 8 second lower lap time.
Great post!
I think you're right on with a lot of points. Regarding Gsum, I think people put an over reliance on it sometimes. At the end of the day, it's laptime that most people are looking for, which comes down to speed. All the other channel, be it brake pressure, throttle position, steering input, or any other, support and describe why the speed channel looks like it does. GSum is a calculation based on speed.
Corner radius is a great channel. To compare turn in, apex, etc, it's sometimes easier to use curvature, which is the inverse of corner radius. Just take your corner radius channel and put "1/" in front.
I think you're right on with a lot of points. Regarding Gsum, I think people put an over reliance on it sometimes. At the end of the day, it's laptime that most people are looking for, which comes down to speed. All the other channel, be it brake pressure, throttle position, steering input, or any other, support and describe why the speed channel looks like it does. GSum is a calculation based on speed.
Corner radius is a great channel. To compare turn in, apex, etc, it's sometimes easier to use curvature, which is the inverse of corner radius. Just take your corner radius channel and put "1/" in front.
Matt, Thank you. I tried to input the math channel curvature into my AIM Race Studio 2 Analysis and my plot was "garbage." The formula was 1/R where R was the equation using the band pass limits of -2000 and 2000. The calculation yields a number that is 0.00×××, but the Math Channel is limited to 3 decimal points. I did not try to multiply 1/R by 1000 to get an integer and allowing for 3 decimal precision.
What are your thoughts? Also, for corner radius R, a shift of the parabola to the right is early apex and to the left is late apex. I know this is true for curvature
Then, there's Danny Nowlan's excellent book, "The Dynamics of the Race Car"
__________________ -Peter Krause www.peterkrause.net www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
Matt, Thank you. I tried to input the math channel curvature into my AIM Race Studio 2 Analysis and my plot was "garbage." The formula was 1/R where R was the equation using the band pass limits of -2000 and 2000. The calculation yields a number that is 0.00×××, but the Math Channel is limited to 3 decimal points. I did not try to multiply 1/R by 1000 to get an integer and allowing for 3 decimal precision.
What are your thoughts? Also, for corner radius R, a shift of the parabola to the right is early apex and to the left is late apex. I know this is true for curvature
Here are screen shots of the radius formula and curvature based on Roger's work. You have to watch the magnitude of numbers on occasion and I think that is what got you. I've had problems with graphs and things when are in the range of 0 to 1. Multiplying by 10 to get 0-10 usually fixes it.
For the radius, it's easy to remember if you think about the tightest part of the radius. If the parabola is left offset, then the tighest part of the turn was at the turn in and it's a late apex. If the smallest radius is at the end of the corner (offset right), then it's an early apex.
I didn't read the links Peter posted up. Bob Knox's book has a good discussion of radius. I'm not sure Danny's book even mentions it, though I would have to check. His book is really on engineering, not data. I don't have it with me, but I'll double check tonight at home.
If this doesn't work, let me know and we'll get you tuned up.
Danny's book did have a couple of paragraphs on using curvature. Good stuff, but not a lot.
I just noticed the math channels in those screen shots is pretty small, so here they are:
absolute curvature is abs(1/(GPS_Speed*MPH2FTS)^2/(GPS_LatAcc*32.2))
Regular would be 1/(GPS_Speed*MPH2FTS)^2/(GPS_LatAcc*32.2)
Hi Matt, l got "garbage" from the two formulae.
I finished reading the 3 book series on "The Science of Speed Series by Brouillard. The Euler Spiral concept makes perfect sense applied to road racing. He did the best explanation on the physics of auto racing
I spent seven years as an engineering student, BS and MS ar Cornell between 1958 and 1965. My engineering background keeps me interested in auto racing at my age.
So, can you help me out with how to implement r curvature into the AIM math channel.
I finished reading the 3 book series on "The Science of Speed Series by Brouillard. The Euler Spiral concept makes perfect sense applied to road racing. He did the best explanation on the physics of auto racing
I spent seven years as an engineering student, BS and MS ar Cornell between 1958 and 1965. My engineering background keeps me interested in auto racing at my age.
So, can you help me out with how to implement r curvature into the AIM math channel.
Thanks,
Tom
I would be glad to help out. Email me what you have in for math channels right now and I'll see what I can get them to do here. My email is matt@trailbrake.net
I would be glad to help out. Email me what you have in for math channels right now and I'll see what I can get them to do here. My email is matt@trailbrake.net
thank you Matt, will email on Saturday and also send the data file I am working with, track is Watkins Glen
Another practical example from Off Camber Data here:
Hi Peter,
I appreciate the resource list. All very helpful and plan to purchase the Kindle version of Graham Templeman's book
This winter I have time to reverse engineer my best lap time at Watkins Glen vs Peter Argetsinger's best lap time driving my 944. I have GoPro video of Peter's laps but not mine. It takes time to reverse engineer but fortunately I have plenty of time plus Peter's video helps in the visualizations. I can establish the best turn in points, the best apex for each corner and establish the brake point and how much brake pressure and how long is the trail braking. I know that I am not trail braking long enough in some corners, specifically turn 1.
I am now ready for data analysis to improve lap times....not ready to purchase an AIM smartycam unless you have a used one for a reasonable price. You were the coach that helped me knock multiple seconds off my lap times with the DOP SVRA.. Racing is challenging and fun, DE is fine when I spend the time with my co-owner, my son-in-law.
12-11-2016, 10:16 PM
