On the simulation stuff, I made a huge step forward in the code. The previous cornering model was pretty crappy to be honest - constant velocity. I changed that up and have brake and throttle modulation working. I also changed the way it solved the straightaways. Check it, suckas-
Some interesting stats on the blog itself... with some of the stats Google started giving me:
- Total views: 12,285 (don't think it started counting until middle of year)
- Views in last month: 3,350
- Views back in September: 1,957
- Followers: 84... that I know of
Despite the slow start this year, think I got a hell of a lot of momentum going here toward the end. Looking forward to 2011 - both personally and professionally. Hopefully making amends with some people (one person in particular), maybe making some decisions on what direction I want my life and career to take. Lot of things to consider.
In any event, I thank all for stopping by and hope everyone has a good holiday. I'll catch you all next year-
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| Jersey Tom - Giants fan, vehicle dynamics engineer, tire data guru, and all around cool guy |
8 comments:
I'm currently working on a lapsim for a project of my own, and I'm wondering where you found accurate straight length and corner radius/banking data for Road America? Or did you manually measure it with Google Earth or something similar? I've tried Googling for some basic numbers, and the layout for ovals are pretty easy to come by but road courses are obviously a little different. Exact numbers aren't necessarily important from a vehicle design perspective, but it would be fun to compare predicted results to DAQ data.
Initially I was looking at data from Google maps and tracing out a racing line on top of it. Eventually someone was willing to share their F1000 daq with me and it is uncanny how closely the two match up. To be honest I was shocked!
Hi Tom,
really interesting work.
Did you use a point mass approach, bicycle model, full vehicle?
Did you consider any downforce?
BTW congratulations for your blog, it's really nice
It is a point mass model. Doesn't use tire data, just a total vehicle friction ellipse (which I've mentioned in an earlier post).
Down force is included, proportional to the square of velocity.
Even as simple as it all is, the results are really crazy close to reality. In effect, if you have an accurate vehicle friction ellipse it can take the place of a full vehicle model with tire data and kinematics... and makes for a fast running simulation.
So did the DAQ come with a GPS trace I take it? Then you just made a simplified version of that?
Nah no GPS. As I think I mentioned in an earlier post, all you really need is speed and lateral acceleration and you can make a trace of inverse corner radius over the lap. That's all you need for a simple track map. It's even a default math channel in MoTeC i2. Obviously doesn't include any banking, but that's fine for this application.
Thanks for all the stuff keeping us interested and perplexed over the year! Looking forward to next years ideas!
Happy holidays Tom
Ed
2:13 is a great point at RA, that is mid to rear of the pack of what people were running at Runoffs, the fast time was high 2:08's. Hopefully next year someone gets the whole BMW engine figured out and top speed goes up for maybe another half second.
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