Garmin Virb Ultra 30

[sennister]

~snip
Sitting in my driveway, waiting for my daughter to gear up and ride with me, the speed sensors say I'm doing 24 MPG while I'm still on a kick-stand. (Vibration perhaps? It's definitely not based on just GPS readings). The G-Force readings when you are on a bike that leans into and out of corners is kind of irrelevant, isn't it? If the unit was held flat, say on a dashboard, it could pick up true G-Force information, but when attached to a motorcycle dashboard that leans into a turn, you get a completely bogus reading.
~snip

I know I said I wasn't going to post a video but the more I was thinking about what you said about the MPH made me think to go in and play with the settings a bit. So here is what is going on in the video....

In the clip I was on the highway on wet roads so I was in economy mode (Sport Intelligent) which dials back the car a bit for better economy but traction control was dialed back which are the warning lights on the instrument cluster. I drive like this in the winter because in default mode the car steps in a bit more than I like. This was the same first drive that the original screen shot was from in the earlier post but I have tweaked the gauges a bit. As I mentioned it is pretty normal for GPS speed to jump around when you first power it on. However in this clip I was probably 25 minutes into my commute and coming up on a red light on the highway and as I came to a stop it went green. So the camera has had plenty of time to get a good 3D fix to minimize the drift as it acquires a good signal. Now my WRX has a sun roof and the camera is strapped to the passenger headrest so ignore all the shaky cam. The key thing I will call your attention to is the speed readings in the lower left corner. The bottom one is OBD-II speed as is the round gauge on the lower right. The speed on the lower left above the OBD-II speed is the one based on 3D GPS. The interesting thing is that as I come to a stop you will see the OBD-II speed show 0 MPH as I came to a complete stop. However while the readings are pretty close the GPS speed never dropped to 0 but got down two 2 MPH. What really shocked me is when I pulled away from the stop light. The GPS speed was consistently much higher than the OBD-II speed. It was reading 10-15MPH faster than OBD-II for much of the time. Even though I was going a pretty constant speed around 63-64 it was reading 10 MPH faster. Before the internet police show up the speed limit on this section of road is 60. It took about a mile of driving before the speeds started to come together. I was shocked by this.

Also ignore the music. No I wasn't listening to that goofy song. I had the radio on and deleted the audio and dropped this song in the place of what was on the radio to avoid any copy-wright issues. This song was available as free use in the Virb Edit software.

[video=youtube;fIEd__I4-8g]https://www.youtube.com/watch?v=fIEd__I4-8g[/video]

 

[BakerBoy]

Interesting ... all those visual blurs and vibrations appear to be mathematically added onto the GPS signal. The GPS' calculated speed, heading, and braking indicators are all highly noisy and sometimes saturated as you actually accel/decel.

Is there a setting available in the Virb to smooth/average/dampen the inertial signals? If not, it appears that the Virb needs to be mounted with a good vibration isolator/dampener. Have you tried a different (like a dash beanbag mount)?

 

[sennister]

Getting back to the original topic, I have the first generation Garmin Virb Elite Camera:

~snip Just quoting you in case you want to follow this a bit more...

Interesting ... all those visual blurs and vibrations appear to be mathematically added onto the GPS signal. The GPS' calculated speed, heading, and braking indicators are all highly noisy and sometimes saturated as you actually accel/decel.

Is there a setting available in the Virb to smooth/average/dampen the inertial signals? If not, it appears that the Virb needs to be mounted with a good vibration isolator/dampener. Have you tried a different (like a dash beanbag mount)?

So I did another test the other day. I don't know that the noise was from a bad mount. Maybe but I am not thinking this is the case because in this second video is from a different trip on a different section of road. This time I used a suction cup mount on the windscreen. Like last time this was about 20 minutes into the the trip but that was edited out because it was boring being stuck behind the cars that are in front of me as the clip starts. I did a bit of searching and I did find something in the Garmin forums stating that calculated GPS speed is for rapid speed changes. Maybe that is the vibrations but this new mount is much more rigid and it goes even more whacky. As in I am going a pretty constant around 70 MPH and I saw readings north of 100MPH. The difference was the mount as well as I had a different back on the case. The camera shipped with a waterproof back and one that isn't waterproof but is to be used when you want the barometric pressure sensor to work. Since this is in the car I had this non-waterproof back on. The Garmin forum did mention that calculated GPS speed does take inputs from other sensors like barometric pressure.

So in this clip as I mentioned, windscreen mount, look at the speed gauges in the lower left. This time there are three of them as I found another one that works much better. The top one is "Recorded 3D GPS Speed" the middle one is the "Calculated 3D Speed" that I used in the first video. The bottom one is the OBD-II speed. For the most part the Recorded 3D Speed is within a couple MPH of the OBD-II and based on the fact that the car doesn't have a calibrated speedometer, once the speed stabilizes it very well could be more accurate than the OBD-II Speedometer. The "Calculated 3D Speed" is even worse than the first video. I am glad I found what appears to be a reliable source for this data as I was dissapointed with the first test. Like before this video was shot in 2.7K with the stabilization enabled. I also deleted the audio as the radio was on and dropped in the free audio from Virb Edit.

[video=youtube;f52UpFCTNHk]https://www.youtube.com/watch?v=f52UpFCTNHk[/video]

 

[JMartin]

~snip Just quoting you in case you want to follow this a bit more...

I'll have to see if I can figure out how to post (YouTube I suppose) one of the few video's I have recorded with my original Virb Elite, of my daughter and I riding together for the first couple times.