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Aisin World Corp. of America: Automobile
Seat Durability Test Stand 
Products Used:
LabVIEW 6.1
NI-DAQ 7.0
Measurement & Automation Explorer 3.0
PXI-1002 Chassis with rack mount kit
PXI-6711 Analog output board
TB-2705
PXI-6071E Multifunction I/O module
SCB-100 Shielded Terminal Block
PXI-6508 Digital I/O Module
CB-100
The Challenge:
V I Engineering Inc. has developed a Seat Durability Test
System for Aisin World Corp. of America. The tests are
performed on up to two seats simultaneously. However,
each test can be individually controlled to perform on
an individual seat.
The tests procedures involve repeated operation of seat
functions along with manual force application to the seat
in pre-determined cycles. Seat performance is observed
for adherence to specification during test operation.
The motor current, motor voltage, travel, load, acceleration,
and the number of cycles completed are monitored and recorded.
The software also provides utilities for editing of the
tests schedules.
The Solution:
Using NI hardware and software for I/O, CLD actuators,
Puritan Automation machining, and Circuit Board Services
custom interface with Allen Bradley drives allowed this
complicated system to come together. The program made
by V I Engineering uses LabVIEW to produce an easy to
use interface for the engineer in the lab to take control
of this large machine.
Abstract:
Aisin's large seat tester requirements push the boundaries
of what linear actuators can do. The stand presses a butt
form against a seat up to 1500N, accurately following
waveforms upwards of 6Hz. The tester applies force to
the seat in 4 axis of motion. Three of the motions are
governed by independently programmable waveforms capable
of functioning in displacement, force, or acceleration
modes. At the same time the stand can run a functional
test on the power track of the seat. The pattern of seat
travel is also programmable. Both varieties of tests keep
track of cycle count, collect data, schedule breaks in
the test to evaluate the seat, and abort based on operator
defined limits.
Overview:
The software is broken up into two tests, a setup for
each, and a few manual-testing options. The Durability
- Manual tab (Figure 1) allows the user complete viewing
of the entire system. The sections of the display are
broken up into force, acceleration, and displacement graphs
with a list of channel options to the right. This lets
the operator choose the channels they want to view on
any graph. The schedule editor allows the user to define
which functions are cycled in the Durability - Manual
test, how many cycles will occur in the test, how often
data should be saved to file and the alarms for the selected
schedule. The editor can be accessed via menu on the main
screen. In order for the system to be flexible enough
to accommodate various seat tests, including future programs,
a simple yet through editor was created.
The Durability - Power tab allows the user complete viewing
of the entire power track system. The sections of the
display are broken up into directional graph pairs. These
display current and voltage of motor. The schedule editor
allows the user to define which functions are cycled in
the Durability - Power test, how many cycles will occur
in the test, how often data should be saved to file, the
tolerance, and the alarms for this schedule. The editor
can be accessed via menu on the main screen.
Cylinder Synchronization
The Analog Output of the system will follow the waveform
pattern viewed in the graph. The waveforms are large arrays
of single precision numbers corresponding to the amplitude
of the output signal. The Update Rate defines the time
between each point. Every point of the curve is synchronized
on all four channels. The software to ensure signal integrity
defines the update rate programmatically. The hardware
does have limitations. The software cannot force the hardware
to do more then it was designed for. In a case that the
user attempts to give the cylinders a waveform outside
of spec, a warning will be given that could possibly result
in an emergency shutdown of the test.
Alarm Limits
To avoid damage to the seat or the data acquisition equipment,
alarm limits are fully configurable for each individual
seat being tested. As long as the alarm channel stays
within the limits placed upon it and all hardware stays
within the hardware limits of the system, the seat will
be considered 'good'. If either alarm is breached for
any of the four axes, the test will stop. There is also
a hardware EStop on the test stand to cut power to the
machine for user safety.
Start / Stop Test
The start buttons on both tests allow the user to start
and stop the manual durability test. When each test is
started, the schedule selected for the seat is run. If
a seat schedule isn't loaded, one can be loaded by selecting
the schedule once Start Test is pressed.
Pause
At any time the graphs may be paused to allow for the
user to zoom in seeing an event in more detail. This only
pauses what the user sees. The test still runs continuously.
The graphs shall continue to stream incoming data when
unpaused. At this time the screens can be printed for
documentation and a .jpg file is saved with the data for
that test.
Data
During a test, at user definable times, a cycle of data
is taken and saved into an excel readable format for convince.
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