Trackaroo Trackmaster

Hi

Really looking forward to trying Trackmaster out for the first time this coming weekend (motorbike track day, Rockingham, UK) as the features look amazing.

If the phone (mine is an HTC Desire) was securely placed under the pillion seat and its height from the ground measured, would it be possible to calculate and record the lean angle? I would imagine it would need a feature to 'set' the phone's angle at 0 degress once it is secured and the rider on board (as it's unlikely to actually get the phone physically level under a seat).

This would be great information to know, perhaps when comparing lines, times and suspension settings through a particular corner.

Thanks for a great app.

Kevin

Hi Jeff

Yes, I was thinking of the built in gyro and not the GPS. I'm not sure how sensitive the gyro is and whether the phone effectively moving through an arc as the bike leans affects the accuracy or the way the angle is calculated, but it would be an interesting feature for those on two wheels.

Kevin

If it was possible to 'zero' the position of the phone within the app after it is mounted it shouldn't matter what the orientation is, i.e. the app would know what angle/level the phone was with the bike upright and could make it's calculations from this starting point.

Vibration might be a problem, perhaps securing the phone on a sponge would help

At my level of riding pinpoint accuracy of lean wouldn't be needed; I would be looking at it as a trend along with different lines and sessions. A few degress wouldn't worry me.

Although the lean would be much less, would this feature help those on four wheels with their suspension settings? Combined with G-forces this could be interesting data through corners.

I spent a fair amount time attempting to get lean angle of motorcycles using 3 axis accelerometers. My conclusion was that it was almost impossible without GPS and or gyro data.

It is possible to find the radius of your turn based on three consecutive data points and finding the center of the resulting circle. With this info and knowing the velocity, you can back in to the geez. At this point you can use the formula geez = (velocity * velocity ) / ( radius * 32.2 ) note that velocity has to be in the units ft/sec and radius is in feet.

Now the last step in this project is to take the arc tan of geez and you get lean angle. One gee comes out to 45 degrees lean angle.

Most likely you will need a fairly fast GPS to get this all to work.

Hope this helps

AW