[step-manufacturing] Minutes of Renton Call #3

[Martin Hardwick]

_Attendees_
Martin Hardwick, STEP Tools, USA
David Loffredo, STEP Tools, USA
Vincent Marchini, Ameritech, USA
Sid Venkatesh, Boeing, USA
Leon Xu, Boeing, USA
Rich Morihara, Boeing, USA
Larry Maggiano, Mitutoyo, USA
Bengt Olsson, Sandvik, Sweden
Magnus Lundgren, KTH, Sweden
Bob Erickson, Pratt & Whitney, USA

_Apologies for Absense_
Fred Proctor, NIST, USA
Fiona Zhao, NIST,/New Zealand
David Odendahl, Boeing, USA
Alain Brail, AlBavis,  France
Mikael Hedlind, KTH, Sweden

We discussed the measurement process that will be used at the 
demonstration. The proposed process includes an "extra" measurement  to 
establish a world coordinate system for the part after the first faces 
have been machined in the first setup. There was some discussion on how 
to insert these coordinates into the Boxy data and it was agreed that 
they should be used to define a setup for the main workplan that 
contains all the other setups and workplans. In the list below this will 
happen at step 4. The additional coordinate systems will then be defined 
for the other setups relative to this coordinate system. For example, in 
step 10 for setup 2 and subsequently for the other setups.

_Process for measuring and generating new NC programs for Boxy._
1. Cut Setup 1 on machine.
2. Measure features on the machine to identify machine reference.
3. Measure three planes on Boxy.
4. Create coordinate system from planes.
5. Rotate part to Setup 2.
6. Measure three planes from Setup 1 on Boxy again.
7. Create coordinate system from planes.
8. Save file with coordinate systems relative to machine reference.
9. Process file to reorient NC model.
10. Generate Setup 2 program from reoriented NC model.
11. Cut Setup 2 on machine.
12. Repeat steps 5-10 for remaining setups.

We discussed how to transfer the results of a measurement from the FARO 
arm to the STEP-NC environment. We can use a text format or a CSV format 
but these carry very little context data. In an exciting new development 
we found that the FARO arm also exports STEP files. We quickly made two 
test files. The first contains the Boxy workpiece input given to the 
FARO arm and some planes measured by the arm. The second contains the 
results of some corner measurements and corresponds to the csv data in 
the Boxy_test files but with real geometry defined for the planes.

ftp://www.steptools.com/private/Renton/Boxy_faro_output.stp
ftp://www.steptools.com/private/Renton/Boxy_measurements_faro_output.stp

Both files contain multiple shape representations and we will need to 
determine which representation should be used to define the faces that 
are to be used for the closed loop machining compensation.

We discussed the schema for the closed loop information model. Two 
changes have been made since the last call.
ftp://www.steptools.com/private/Renton/Closed_loop_model.txt

1. The measurement_workingstep has been divided into a 
measurement_execution_workingstep that will get/create the measurement 
data and a measurement evaluation workingstep that will evaluate the 
measurement data to create the geometry needed for a compensation.

In the demonstration we will use the measurement_execution_workingstep 
to get the measurement data from the FARO arm and the 
measurement_evaluation_workingstep to create an axis2_placement_3d 
entity from the 3 planes created by the arm. The axis2_placement_3d will 
then be used to define the new setup.

2. To make it easier to understand, the compensation_workingstep has 
been enlarged to include more of the data that was previously in 
sub-entities. The workingstep now has three main attributes: a set of 
items to be corrected, a measurement defining an error that needs to be 
corrected, and an operation that determines how much of the error is to 
be corrected in this step.

The next call will be at the regular times on Wednesday August 25.

The video recording for this weeks call includes images of the data 
returned by the FARO arm.
ftp://www.steptools.com/private/Renton/stepmanuf_telecon_20100818.wmv

Written at 30,000 feet using an Airplane WiFi and respectfully submitted by

Martin Hardwick
Team Leader STEP-Manufacturing

Action Items
----------------
Rich Morihara and Martin Hardwick to investigate the options available 
for STEP output from the FARO arm
Martin Hardwick to "stress test" the closed loop machining model using 
the process proposed for the demonstration
David Loffredo to map the closed loop machining model into the AP-238 AIM

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