Impossible lateral acceleration data

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Harry
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Re: Impossible lateral acceleration data

Post by Harry »

MrBlah wrote:They all use track addict or the dedicated hardware solutions
LapTimer imports HLPTRL, VBO, NMEA, GPX.

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Re: Impossible lateral acceleration data

Post by MrBlah »

Ohh I did not know that I'll try it toniggt
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Re: Impossible lateral acceleration data

Post by MrBlah »

Oops I can't, hlt does not split my laps right, I end up with a 1 min lap in there, circuit tools split them correctly
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Re: Impossible lateral acceleration data

Post by gplracerx »

As I've said several times before, CT is worth the money you paid for it, i.e. nothing. CT does have an acceleration calculation smoothing function. I don't think it will help, though. CT is designed to be used with Racelogic devices like the Vbox Sport. The Vbox Sport gives you two more significant figures on the latitude and longitude data, ten instead of 8. That allows for a much better calculation of speed and acceleration from GPS data at 20Hz.

RaceLogic has an IMU add on for their high end data loggers, if you want to spend multible kilobucks. Otherwise acceleration is calculated, not measured directly.
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Re: Impossible lateral acceleration data

Post by MrBlah »

where is the smoothing function in ct?

I've already spent more than I want on this racecapture pro
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Re: Impossible lateral acceleration data

Post by gplracerx »

It's on the graph tab in the top menu. There's a box called acceleration/smoothing. Enter a number in the box. Bigger numbers give more smoothing at the cost of the usual distortion from low pass filtering.

I don't think it will help, though, because of the low resolution of the RaceCapture GPS. After conversion to decimal degrees, the VBox Sport has seven decimal places compared to six for the RaceCapture. To calculate speed and acceleration, you subtract two large numbers to get a small number. With only six decimal places, that usually means no more than one significant figure, especially at a high data rate like 20 or 25Hz. As a result, I doubt it's worth going higher than 10Hz like the XGPS160, which also has only six decimal places for decimal degrees.
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Re: Impossible lateral acceleration data

Post by MrBlah »

it helped a tiny bit, it's really strange that it's repeatable every single lap looks the same, lat is bad but long and speed are fine
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Re: Impossible lateral acceleration data

Post by MrBlah »

Importing the vbo from trackaddict fails, HLT hangs for a while then crashes
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Re: Impossible lateral acceleration data

Post by gplracerx »

MrBlah wrote:it helped a tiny bit, it's really strange that it's repeatable every single lap looks the same, lat is bad but long and speed are fine
CT is probably calculating lateral acceleration using the heading data. The easiest way is to use speed and yaw rate. But the heading data using a RaceCapture device is not calculated correctly by HLT at the moment so the yaw rate will be wrong too. Harry says he has a fix in the works, but it's not out yet.
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