Author Topic: DistoX2 Calibration issue, Solution (had to do more than just leave the house*)  (Read 6771 times)

Offline blhall195

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I have spent the majority of today trying to fix my Disto. I've finally done it! I didn't find this solution online so figured I'd share it...

So it had recently been dropped and the calibration was thrown massively out of whack - i.e. there were 60-80° of change  in the compass reading when I rolled the Disto - pointing it in the same direction.

I'm not sure if this is the case for Pocket Topo, but with TopoDroid (Android OS) calibration data is normally grouped together automatically as the software just matches up similar looking readings.

It seemed with my semi broken Disto, TopoDroid was having working out which readings were which, due to the huge difference in readings that were supposed to be similar, leading to the error message (not enough data) even though I was absolutely sure I had taken all 56 readings correctly! Had the readings had a slightly smaller variance, things would have been okay, TopoDroid allows you to simply up the threshold on what it considers an acceptable variance for one group of 4 data sets. However it was the case that I couldn't do this.

Turns out it is possible to manually group the data by going down the list of 56 readings on the calibrations screen pressing on each individual one and numbering them like so... 1111,2222,3333,4444,5555 and so on for all 56 readings. After doing this the disto only had a 5° deviance while being rolled. Allowing me to calibrate it more precisely and get it to below 1° variance in the end.  :smartass:
« Last Edit: October 24, 2015, 10:55:07 pm by Hall2501 »

Offline blhall195

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Seems I may have gotten a little over exited yesterday, tried to calibrate the disto again in the cave – ending in a failed surveying trip (always bring backup instruments!). Still couldn't get the calibration co-efficient to below 0.5°. Summarised the story so far lab report style on the way back in the car to work out what to do next.

Observation:
Disto showed a <80° variance when rolled 360° pointing forwards.

Cause:
Disto dropped, on a previous caving trip, began experiencing problems immediately afterwards.

Hypothesis:
The diso can be fixed via factory reset and recalibration.

Method:
Recalibration preformed indoors for convenience.

Results:
Failed to calibrate diso, automatic grouping of data impossible due to large differences in readings that were supposed to be the same.

Conclusion:
Couldn’t recalibrate my disto, probably because I was indoors & the magnetic field was too disturbed.

Hypothesis:
Calibration failed as I was indoors and the magnetic field of my environment was disturbing my disto readings.

Method:
Disto was taken to some woods and rolled 360°

Results:
Disto appeared to show a smaller variance when rolled pointing forwards outside.

Conclusion:
The problem must have been the disturbed magnetic environment of the house/bulidings. However this would not be enough to cause +40° variance.

Follow up:
Calibration carried out in a park. But topodroid could not automatically distinguish between/group data sets in order to complete calibration.

Hypothesis:
It is possible to manually assign calibration data.

Method:
Assigned all 56 data sets into groups of 4, via 1111, 2222, 3333,.

Results:
Calibration was successful with a 1.5° calibration coefficient.

Conclusion:
Manual assignment of data is a promising solution, however calibration coefficient needs to be below: 0.5° in order to be acceptable. A more precise calibration procedure in a extremely none magnetic environment such as a cave might work.

Hypothesis:
Calibration in a cave with a very controlled calibration method, might bring calibration co-efficient to below 0.5°

Method:
Calibration carried out in a cave very precisely with disappointed assistant.

Disappointing results:
Calibration co-efficient still above 0.5°

Conclusion:
Next attempt to fix it will be to update the firmware, if this doesn’t work I’m going to assume it is a problem with the board itself.

The manual says: "the acceleration sensor used for the inclination measurement is a delicate part. It can be damaged mechanically by large accelerations (strokes or drops)."

so it could be that it needs fettling or replacing, unfortunately I don't know how to do this so may ask someone else for help. Maybe ask someone to replace the board.

Offline blhall195

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Turn's out the firmware was the latest version, looks like I'll need to relace/get the board fixed :'(

Offline blhall195

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Might try using different software to calibrate it.

Offline KristianBrook

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This has made me smile. More lab report style writing please.
WHERE IS THE MUD!?! I WAS PROMISED MUD!!!

Offline blhall195

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after the most precise calibration I've ever attempted in a cave, used string to measure exact angles ect, these are the readings the disto gave out:

Format: Compass, Clino...

TopoDroid v 2.6.0a

# Calibration CVX
# 2015.10.25
# 00:13:43:0C:7C:C6
#
1,  95.11, 0.83,
2,  96.16, -1.09
3,  92.89, 2.19,
4,  93.36, 1.33,

5,  171.33, 3.50
6,  219.63, 2.10
7,  183.15, 3.84
8,  140.90, 3.29

9,  261.59, 1.69
10, 266.79, 0.12
11, 260.26, 1.33
12, 204.35, 1.69

13, 11.31, 0.56
14, 314.91, -1.03
15, 350.00, 0.61
16, 44.24, 0.16

17, 175.31, 87.31
18, 112.79, 88.72
19, 136.90, 88.50
20, 258.97, 86.76

21, 245.35, -88.81
22, 248.11, -84.76
23, 277.96, -84.18
24, 152.70, -86.46

25, 65.14, -49.11
26, 30.30, -44.28
27, 138.19, -45.46
28, 97.85, -49.20

29, 156.95, -51.71
30, 223.98, -48.59
31, 189.58, -47.25
32, 147.89, -50.58

33, 304.32, -53.65
34, 268.36, -52.43
35, 244.53, -44.93
36, 212.20, -52.85

37, 126.97, 51.39
38, 95.51, 50.55
39, 45.21, 52.77
40, 164.56, 48.80

41, 180.00, 48.65
42, 216.00, 49.08
43, 183.96, 45.60
44, 137.89, 46.99

45, 227.45, 46.59
46, 265.51, 46.78
47, 298.55, 46.23
48, 190.65, 47.30

49, 23.32, 49.30
50, 311.41, 50.43
51, 357.77, 50.78
52, 54.12, 48.53

53, 30.34, 48.65
54, 356.26, 45.08
55, 348.45, 45.60
56, 370.28, 46.99

Full details of the calibration trip can be found here...

http://www.ulsa.org.uk/rants/rant.php?rant_id=972


Offline maxf

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I made a calibration jig yesterday.

It's a long piece of wood (2m) with two flats bit of wood sticking up at each end, one to rest the end of the disto on. The other to for the laser to hit.

These are attached using plastic plugs, no metal used in the construction.

The thing can them be laid on the ground in various orientations and the disto rotated in its required positions with excellent repeatability.

It can also be proped up at  an angle for the vertices shots or tested against a tree vertically.


Went out to try and calibrate my disto yesterday and the best value I got was just over 1°

Need to have another go..

Offline blhall195

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When you did your calibration did you get similar readings the the one's shown above? Was the compass variance very wide when you rolled the disto?

Offline maxf

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Not as much as yours...

For example

48.9
35.5
43.9
56.6

Were my worst ones...

Offline 2xw

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Hahahahahahahahaha

Offline blhall195

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Few more experiments done by someone more technical than I:

Hypothesis:

Board is fucked

Experiment:

Board removed from disto and placed in another unit

Results:

Surprisingly DistoX works fine

Conclusion:

Something has happend to the lenica unit to cause the board to stop working, tried replacing the board back in the original disto same problem as before, looks like I'm gonna have to keep the board and battery but replace the lenica unit.

At least I've finally gotten to the bottom of this.
« Last Edit: November 02, 2015, 11:05:52 pm by Hall2501 »

Offline Olaf

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As far as I know, the Disto X2 uses the accelerometer (clino) built into the Leica. Probably that one is broken, while the laser and the compass (built onto the replacement board) are still fine.

As a side note, it appears that newer Leica X310s are fitted with a different accelerometer that behaves non-linearly, which requires a slightly different calibration procedure, which should be implemented in both PocketTopo and TopoDroid.

Offline blhall195

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Ahh, I assumed accelerometers were built in with the compass. But I guess it makes sense for the lenica to have the Clino if it's expected to do trigonometry and stuff. 

Offline Swallowneck

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What delta value are you actually getting, if you get >.5 then by how much. I ask because I have a newer Disto which I could never get below .5 until Beat released  firmware version with the the non-linearity correction added. So when I calibrate now I get around .52 then apply the correction and it drops to .26 ish. A rotation test then gets me less than .6 of a degree variance.
Before you condemn your unit make sure you have done this correctly.

Quote from Beat's FAQ's.
Q:

I carefully calibrated my DostoX2 but I do not get a delta below 0.5.

What is wrong?

 

A:

In some X2 devices the acceleration sensors have a significant non-linearity. This reduces the precision of the device.

A new version of the firmware and calibration software allows to compensate this error. To use it do the following:

- If your firmware is below 2.3, use the Updater to reload it.

- Use PocketTopo Version 1.372 to do the calibration.

- During calibration activate the ?NL? option in the menu to enable calculation and transfer of the non-linearity correction coefficients.

You can do this with existing calibration data; there is no need to redo the calibration measurements.

If your device is affected you will notice a significant reduction of the delta.

Do not use the ?NL? option for DistoX1 devices or firmware versions below 2.3!

 

Offline caver.adam

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When I run the calculation (on topoDroid) I get the same exact answer regardless of whether I check NL or not. Exactly the same. But my disto is 2.3. Does anyone know if the computer software will tell me whether I have an NL issue without me upgrading the disto?

I don't have a pockettopo capable computer at the moment. That's why I haven't updated my disto. But I'm consistently getting 0.8 to 0.9 when I calibrate.

Offline Swallowneck

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FW 2.3 should work but I have no experience of Topo Droid so can not comment.
I would get a Dell Axim and Pocket Topo, that seems to be the most popular combination and it works well once you get your head round the Windows.net and the Dell com port stuff. Plenty of info on here about those two lovely items.
Good luck.

Offline blhall195

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I've finally got it working with the help of some friends :)

The only difference: This time I used Pocket topo instead of Topo-Droid

Came out with the co-efficient: 0.3

Whats more the disto readings appeared more reasonable - strange. I guess it was either me or topodroid - might have changed the settings accidentally, I guess I'll find out when I try calibrating someone else's disto

compass clino

 21.8   -6.3
 20.9   -6.2
 20.8   -6.2
 21.9   -6.3
200.7    6.1
201.7    5.9
201.8    6.1
200.9    6.0
299.2   -0.6
298.6   -0.6
298.7   -0.5
299.2   -0.6
119.0    0.2
119.5    0.2
119.5    0.1
119.1    0.1
204.8   86.9
203.9   87.4
182.6   87.6
186.9   87.1
 13.6  -87.4
 28.4  -87.3
 22.8  -87.7
 13.7  -87.4
347.3   10.8
346.0   10.8
345.8   10.9
346.8   10.8
166.2  -11.4
166.7  -11.1
167.1  -11.3
166.3  -11.3
164.0   16.9
164.6   16.7
165.0   16.9
164.6   16.8
345.0  -17.1
344.2  -17.0
344.1  -17.3
344.9  -17.1
240.3   19.4
240.5   19.3
240.7   19.2
240.8   19.4
 60.9  -19.5
 60.4  -19.4
 60.5  -19.6
 61.0  -19.7
 63.4   10.2
 62.9   10.3
 62.6   10.4
 63.1   10.1
242.3  -10.8
242.8  -10.6
242.8  -10.7
242.2  -10.5








Offline maxf

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That's good news. I'm still at the 0.8° level.

I may try pocket topo

Offline footleg

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I made a calibration jig yesterday.
It's a long piece of wood (2m) with two flats bit of wood sticking up at each end, one to rest the end of the disto on. The other to for the laser to hit.
These are attached using plastic plugs, no metal used in the construction.
The thing can them be laid on the ground in various orientations and the disto rotated in its required positions with excellent repeatability.
It can also be proped up at  an angle for the vertices shots or tested against a tree vertically.
Went out to try and calibrate my disto yesterday and the best value I got was just over 1°
Need to have another go..

When using a jig of some sort, you cannot rest the side of the Disto body against a surface to ensure accurate positioning. For one thing the side of the Disto case are not parallel to each other, but also significantly the angle the laser points out of the Disto body is not necessarily parallel to the body of the device either. So it is vital to aim with the back of the Disto body (actually the point on the rear face of the body opposite the point where the laser emerges from the front) pressed up to a static point, and for the laser spot to hit the same a point target for each position in the barrel rolls (each set of 4 readings).

I think from your description you are doing this with your jig? I like the idea that it provides a convenient station point and target area to aim at which you can position in any orientation. But I am not sure the accuracy you can calibrate to over just a 2m distance. I try to look for 5m minimum (I generally calibrate in the cave using whatever rock points and target spots I can find). I have managed a good enough calibration once in a passage only 2m wide (I was between pitches and only had 3 move legs to measure when the batteries ran out and I had to re-calibrate with fresh batteries before we could measure the last 3 legs. Most of the passage was around 0.5m wide, so 2m was the widest point!).

Offline maxf

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If the sides arent parralell then how are you supposed to find out where the ref point is on the rear of the case based on measurements from the sides on the front of the case ?

I thought distance didn't come into the calibration ?

 
I made a calibration jig yesterday.
It's a long piece of wood (2m) with two flats bit of wood sticking up at each end, one to rest the end of the disto on. The other to for the laser to hit.
These are attached using plastic plugs, no metal used in the construction.
The thing can them be laid on the ground in various orientations and the disto rotated in its required positions with excellent repeatability.
It can also be proped up at  an angle for the vertices shots or tested against a tree vertically.
Went out to try and calibrate my disto yesterday and the best value I got was just over 1°
Need to have another go..

When using a jig of some sort, you cannot rest the side of the Disto body against a surface to ensure accurate positioning. For one thing the side of the Disto case are not parallel to each other, but also significantly the angle the laser points out of the Disto body is not necessarily parallel to the body of the device either. So it is vital to aim with the back of the Disto body (actually the point on the rear face of the body opposite the point where the laser emerges from the front) pressed up to a static point, and for the laser spot to hit the same a point target for each position in the barrel rolls (each set of 4 readings).

I think from your description you are doing this with your jig? I like the idea that it provides a convenient station point and target area to aim at which you can position in any orientation. But I am not sure the accuracy you can calibrate to over just a 2m distance. I try to look for 5m minimum (I generally calibrate in the cave using whatever rock points and target spots I can find). I have managed a good enough calibration once in a passage only 2m wide (I was between pitches and only had 3 move legs to measure when the batteries ran out and I had to re-calibrate with fresh batteries before we could measure the last 3 legs. Most of the passage was around 0.5m wide, so 2m was the widest point!).

Offline Spike

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I thought distance didn't come into the calibration ?

Distance doesn't, however if your four orientation shots vary across a 1cm target 10m away, the max angle error between them at the disto (~0.05o) is much smaller than if the 1cm target is 1m away (~0.5o) thus helping the calibration.

If your jig fixes this in place though, so you're not targeting the laser at a particular point each time, I don't think it would cause a problem - at least not in the way I'm envisaging your jig (and the one I indent to build at some point)

HTH, I've rewritten it three times to try and be clearer - not sure it's worked...

Offline maxf

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But i'm more likely to wobbling the laser around quite a bit over a larger distance and not actually targeting the same spot each time...

I had made a another thread showing my jig, the photos didn't show up but there is a link to the album

http://ukcaving.com/board/index.php?topic=19310.0

Offline Spike

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I get what you're saying, but at least with a long shot you can tell when you've missed and therefore got a dodgy angle, and can redo the measurement. If you're targeting a closer spot of the same size, you could get the same error by hitting both sides of the same target without knowing about it.

I've got a plan for my own jig - I might try and put some of it together this weekend and if I do I'll add details to your other thread.

Offline cavermark

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Isn't it better to get practiced at calibrating by hand (no jiggety ;-) ) for the times when you need to recalibrate in a cave (or on an expedition etc.)?

Offline wookey

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Brendan, if you think that PocketTopo gave meaningfully different calibration results in this case to TopoDroid, then do tell Marco about this thread, as I'm sure he'd be interested. Topodroid nominally implements exactly the same calibration algorithm as PocketTopo so it really shouldn't matter.