Dual axis compensator VS IMU

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b_clive
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Dual axis compensator VS IMU

Post by b_clive » Tue Oct 02, 2018 8:26 am

Maybe it's a stupid question but just out of curiosity:
What is the main difference between and dual axis compensator and the new IMU tilt? I found some reliable answers about the dual axis compensator but none that really made it clear about IMU. Also regarding the dual axis compensator Is it ever good practice to switch the compensator off?

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Re: Dual axis compensator VS IMU

Post by pburrows145 » Tue Oct 02, 2018 9:19 am

Consider a whole can of worms.
Now consider it opened... :lol:

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Re: Dual axis compensator VS IMU

Post by smacl » Tue Oct 02, 2018 9:27 am

pburrows145 wrote:
Tue Oct 02, 2018 9:19 am
Consider a whole can of worms.
Now consider it opened... :lol:
Nice. Coffee spat all over my keyboard. Cheers Paul! :)

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Re: Dual axis compensator VS IMU

Post by Formula1982 » Tue Oct 02, 2018 9:58 am

b_clive wrote:
Tue Oct 02, 2018 8:26 am
Maybe it's a stupid question but just out of curiosity:
What is the main difference between and dual axis compensator and the new IMU tilt? I found some reliable answers about the dual axis compensator but none that really made it clear about IMU. Also regarding the dual axis compensator Is it ever good practice to switch the compensator off?
i'll answer the relatively easy bit of your question: I would keep the compensator on as standard unless its set up on a structure that isn't in a stable position. For example on an offshore platform or vessel where it's obviously moving under you. The compensator is pretty much always a good thing to have in most any other situation.

I'm going nowhere near the rest of your question about the relative accuracy of an IMU unit. :D

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Re: Dual axis compensator VS IMU

Post by b_clive » Tue Oct 02, 2018 12:14 pm

Thanks, Formula1982 for your answer. That is what we usually do. The compensator is always on by default. We did once do some scans on an oil rig and we did switch off the compensator as well as you said. So what would happen to the data if for instance the compensator is off and let's say we are on the oil rig and during the measurement it starts to sway? Would that data be unusable? cause like I said we did have compensator off while scanning on the rig and the data came out pretty much normal.

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Re: Dual axis compensator VS IMU

Post by pburrows145 » Tue Oct 02, 2018 1:33 pm

As long as your scanner stays relative to the object in motion you should be fine: on a ship/oil rig etc.

If you have it on, and the object starts to move, that's when you will get a warning (with any scanners that have a real-time dual axis compensator ;) )

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Re: Dual axis compensator VS IMU

Post by Formula1982 » Tue Oct 02, 2018 4:37 pm

b_clive wrote:
Tue Oct 02, 2018 12:14 pm
Thanks, Formula1982 for your answer. That is what we usually do. The compensator is always on by default. We did once do some scans on an oil rig and we did switch off the compensator as well as you said. So what would happen to the data if for instance the compensator is off and let's say we are on the oil rig and during the measurement it starts to sway? Would that data be unusable? cause like I said we did have compensator off while scanning on the rig and the data came out pretty much normal.
Depending on what scanner and software you're using, the data should still be fine as long as you can toggle all the scans to 'unlevelled' before you start your registration.
You can be scanning on a boat with it pitching and rolling during the scans, but as long as the objects are moving together (ie the rest of the boat), then all the scans with the compensator off will look 'normal' and 'level' relative to the boat.

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Re: Dual axis compensator VS IMU

Post by b_clive » Tue Oct 02, 2018 10:46 pm

Thank you, it’s pretty clear now :)

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Re: Dual axis compensator VS IMU

Post by GavFoster » Wed Oct 03, 2018 2:21 pm

Over 650 views and no answer. Is this another feature we think we need but don't know what it does ? :D

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Re: Dual axis compensator VS IMU

Post by tbwester » Wed Oct 03, 2018 2:56 pm

If you don't know if you need it, then you don't need it :)

On Leica machines, the DAC is incredible accurate and allows for precise level over very long distances. It also can clean vibrations from the scan (if scanning on a vibrating floor).

For MOST scanning folks on MOST projects, there is a little or no difference in the two techniques. And even if there is a difference, very very very few projects ever even need the accuracy of a DAC.

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