Harry's GPS Suite Forum

www.gps-laptimer-forum.de
It is currently Sat Jul 26, 2014 12:10 pm

All times are UTC [ DST ]




Post new topic Reply to topic  [ 7 posts ] 
Author Message
PostPosted: Sun May 19, 2013 7:47 am 
Offline
Fewer than 10 Posts
Fewer than 10 Posts

Joined: Sun May 19, 2013 7:39 am
Posts: 3
Has thanked: 0 time
Been thanked: 0 time
Is there a way to make the GPS calculation the default for accelerometer calculations? Using the iPhone doesn't work well on a motorcycled since the bike is leaned over in a corner and not flat like in a car.


Share on FacebookShare on TwitterShare on MySpace
Top
 Profile  
 
PostPosted: Mon May 20, 2013 7:29 am 
Offline
Site Admin
Site Admin
User avatar

Joined: Sun Sep 12, 2010 10:32 am
Posts: 4429
Location: Cologne, Germany
Has thanked: 52 times
Been thanked: 132 times
That is not possible currently. I'm working on a feature to both record lat acceleration and lean angle on motorcycles. Once it is available (v18/19), you will hopefully have no need for this calculation any more :-)

Harry

_________________
Image Image Image Image


Top
 Profile  
 
PostPosted: Mon May 20, 2013 5:42 pm 
Offline
Fewer than 10 Posts
Fewer than 10 Posts

Joined: Sun May 19, 2013 7:39 am
Posts: 3
Has thanked: 0 time
Been thanked: 0 time
That would be awesome. Thank you very much.

I have another question.

I'm trying different lines at the track I'm riding and am trying to relate those to the times I'm getting. The app I use to use on android would show my exact lines in respect to the track map. So you would have the track map laid out like a road and the line I was taking within the boundaries of that road. Is that function somewhere in this program?


Top
 Profile  
 
PostPosted: Mon May 20, 2013 6:30 pm 
Offline
Site Admin
Site Admin
User avatar

Joined: Sun Sep 12, 2010 10:32 am
Posts: 4429
Location: Cologne, Germany
Has thanked: 52 times
Been thanked: 132 times
Please export your laps to .kml and watch in Google Earth. In my experience, GPS accuracy needs to be really high to derive reasonable information from plot comparison.

- Harry

_________________
Image Image Image Image


Top
 Profile  
 
PostPosted: Mon May 20, 2013 6:35 pm 
Offline
Fewer than 10 Posts
Fewer than 10 Posts

Joined: Sun May 19, 2013 7:39 am
Posts: 3
Has thanked: 0 time
Been thanked: 0 time
I'm using the XGPS150 with my iPhone. I hope that would be good enough since I was able to do this before with just the Android phone though the tracking frequency made the plotting very coarse but it was still distinguishable and it was visible on the phone app without exporting.

The reason this is super useful in phone is that I can check it quickly between sessions rather then waiting until I get home to use a computer.

Thank you again for your quick replies and great app.


Top
 Profile  
 
PostPosted: Thu May 30, 2013 9:30 pm 
Offline
20 or more Posts ★★★
20 or more Posts ★★★

Joined: Thu May 03, 2012 5:26 am
Posts: 282
Has thanked: 6 times
Been thanked: 6 times
Harry wrote:
That is not possible currently. I'm working on a feature to both record lat acceleration and lean angle on motorcycles. Once it is available (v18/19), you will hopefully have no need for this calculation any more :-)

Harry


You need pitch as well to correct for elevation change. To have any hope of doing that properly, you need vertical as well as horizontal velocity from the GPS, even if the vertical velocity will never be as precise as the horizontal velocity by the nature of GPS. You should also be calculating horizontal acceleration from the GPS velocity and rate of heading change rather than position. Calculating vertical velocity from the altitude reading is really, really noisy. The VBOX Sport is supposed to give vertical velocity, but it isn't working right now. And that's been acknowledged by RL, it's not just a problem with my box.

I've looked at the vbo file from the SD card in my VBOX Sport, and I see changes in velocity when there is no change in position because of insufficient resolution of the position. Interestingly enough, you also get lateral and lineal acceleration, although right now the column labels are reversed. Surprisingly, when you open the vbo file in Circuit Tools, it recalculates the accelerations.


Top
 Profile  
 
PostPosted: Thu May 30, 2013 10:14 pm 
Offline
Site Admin
Site Admin
User avatar

Joined: Sun Sep 12, 2010 10:32 am
Posts: 4429
Location: Cologne, Germany
Has thanked: 52 times
Been thanked: 132 times
When *calculating* acceleration you will apply different calculations in real time and in an analytics tool like CT. In real time you cannot look ahead and use this fixes ahead to calculate acceleration. In case you do it after the fact, you will use fixes surrounding the position acceleration is calculated for, and apply additional smoothing like a Kalman filter. I assume acceleration calculated by CT is a better approximation of reality than that written in realtime by the VBOX. LapTimer's acceleration calculation is not too sophisticated today, but it makes exactly that differentiation.

- Harry

_________________
Image Image Image Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 7 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group