|
jacobdrachmann
Posts: 1
Joined: 7/27/2012
|
17000 points in space |
Flag »
Reply »
|
| Hello, I am currently working on a project where i need to install i.e. 17000 fixtures for a spatial roof structure. I need to mount the fixtures in unique posisition due to the shape of the roof surface. The surveyor on the project has a Leica 1203 totalstation, and my request is ideas to handle the large amounts of points to be able to methodically place the fixtures. The points are extracted from a Rhino3D model, and can be given as a spreadsheet - the surface will most likely be handled in sections of 100 fixtures. Any ideas will be appreciated! Best, Jacob Drachmann Civil Engineer Pihl & Søn A/S - Denmark |
|
| |
Friday, July 27, 2012 at 4:52:25 AM |
|
Kate
Posts: 9
Joined: 11/6/2008
|
|
Re: 17000 points in space |
Flag »
Reply »
|
Response from our Editorial Board member:
Without knowing more details of the project, it appears that this
layout should be fairly easy to execute in the stakeout mode of standard
surveying software and total stations. The laser "pointer" mode can be
set and if it is dark enough then the layout points will be visible. You
noted that the unique position of the fixtures due to the roof shape;
you may want to to add 3 or more alignment marks on each fixture in the
model (if 3D alignment is required). Also include in the model many
reference marks for the total station to backsight on.
Renting construction layout lasers could be cost effective for a
one-off layout of this kind, but the total station should be fine
(depneding on light conditions).
Exporting 3D linework will help the total station operator visualize
the layout in the surveying (data controller) software. Most software
can intake DXF, and your spreadsheet can be imported as a delimited
point file. Another interesting layout tool is the 3D-Disto - a kind of
mini-total-station desgined for BIM and building construction layout
work.
|
|
|
Kate
Posts: 9
Joined: 11/6/2008
|
|
Re: 17000 points in space |
Flag »
Reply »
|
Response from our Surveying Editor:
This
reply is necessarily based on some degree of assumption since there
isn't really enough info to give a step-by-step definitive answer.
Mr. Drachmann mentions 17000 fixtures FOR a roof structure, but further comments indicate that he means "on" a roof structure.
We could further infer that he likely means "on the ceiling", but says
on the roof - two (2) entirely different things which I will deal with
momentarily.
The mention of extracting points from a Rhino3D model indicates the
presence of a 2D datum in North and East plane coordinates, with
elevations as the third dimension. Since he speaks of staking out for
fixtures using a Leica instrument we must also assume that the 3D
coordinate system for the structure also exists on the ground.
First - Read the manual for either the data collector or controller that
the surveyor intends to use to operate the instrument, or, the manual
for the instrument if the surveyor intends to use the onboard programs.
In this way determine what formatting conventions the program uses
for point files, and how they must be delimited - by commas, by spaces,
etc. Then, number the points extracted from the 3D model, save the
delimited file, and transfer it to the stakeout software. Break it into
manageable sized (100) point groups if necessary.
Second - The Leica 1200 series can be optionally fitted with PinPoint - a
reflectorless EDM (RL mode.) If this one has PinPoint the Laser will
make a small dot on the structure at the appropriate place when marking a
point regardless of being on the roof or on the ceiling.
Third - If the Leica 1203 does not have PinPoint then the fixtures must
be staked out using a prism on a pole or a point. This means that
accounting must be made for a prism height. In the stakeout software the
prism height will be automatically subtracted. This is ideal if the
fixtures are on the roof of the structure since a subtracted rod height
will give you the correct elevation on the roof surface. HOWEVER, if you
are staking on the ceiling of the structure then you must enter the rod
height as a negative number which will algebraically correct the elevation, since a rod height held under something would need to be added to produce the correct elevation.
|
|