A voice-actuated wind tunnel model leak checking system was developed. The system uses a voice recognition and response unit to interact with the technician along with a graphics terminal to provide the technician with visual feedback while checking a model for leaks

Larson, W. E.

English

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NASA Technical Memorandum 86359
NASA-TM-8635919850009627
AVOICE-ACTUATED WIND TUNNEL MODEL LEAK
CHECKItIG SYSTEM
WILLIAM E. LARSON
FEBRUARY 1985
• NI\SI\
National Aeronautics and
Space Administration
Langley Research center
Hampton, Virginia 23665
https://ntrs.nasa.gov/search.jsp?R=19850009627 2020-03-20T20:12:50+00:00Z

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SUMMARY
A voice-actuated wind tunnel model leak checking system has been developed.
The system uses a voice recognition and response unit to interact with the
technician along with a graphics terminal to provide the technician with visual
feedback while checking a model for leaks.
INTRODUCTION
When a model is placed in a wind tunnel for testing, it is connected to
pressure measuring devices with small diameter plastic tubing and stainless steel
tubing. This installation is a tedious task, and errors in plumbing can easily
occur as the number of orifices on a model can frequently exceed one thousand.
Leaks can be caused by the improper installation of the plastic tubing over the
stainless steel tubing. The soldered joints of the stainless steel tubing
sometimes leak also. Whatever the source, these leaks must be detected and
repaired so that erroneous test results do not occur.
The previous method for leak checking required two or three people. As shown
in figure 1, one technician applies pressure to an orifice on the model while
another technician in the control room selects, via a control panel, the orifice
being tested. Once the pressure has been applied, a third technician, who
generally handles the intercom and record keeping duties, requests a decision
on the leak rate from the control room technician who can see the pressure
displayed on a CRT in the control room. These steps are repeated until all the
orifices have been checked.
Due to the number of technicians and the amount of time required to perform
this relatively simple task, an effort was undertaken to improve the model leak
checking procedure. The result was a computer program that interfaces with the
technician via a voice recognition and response unit. This paper will discuss
the requirements that led to the development of this leak checking system as well
as the capabilities of the system.
THE WIND TUNNEL MODEL LEAK CHECKING SYSTEM
The computer-based Leakcheck system was developed to allow the computer to
perform more of the work done in checking a model for leaks with the objective
of reducing the manpower and time required to perform the task. To eliminate
the need for a control room technician, it was necessary to provide the
technician applying the orifice pressure the ability to select the orifice to be
tested. An early prototype system considered the use of a portable terminal.
This allowed the technician to select the orifice from a keyboard but did not
allow his hands freedom to work on the model. Therefore, a voice recognition
system was chosen for this task.
The voice system used is capable of voice recognition and response. The
recognizer is a speaker-dependent, isolated command unit that can handle a
vocabulary of up to 100 separate commands. A command can be a single word or a
phrase with a duration of 1.5 seconds or less. Each technician trains the
Leakcheck vocabulary by speaking each command as directed by the program. After
all the commands have been trained, their patterns are stored on a disk file for
recall when the technician wishes to use the program again. The voice response
unit is a speech synthesizer that is capable of speaking any number of words.
It uses an algorithm that converts English text strings to speech. With these
recognition and response capabilities the technician can issue commands to the
computer and get positive response via the spoken word.
To give the technician some visual feedback in the leak checking process, a
CRT which displays information about the orifice currently being checked is
included in the system. An example of this display is shown in figure 2. The
first two columns in the upper left of the screen contain information about the
orifice currently selected. The orifice number and the data channel to which
the orifice is assigned are displayed in the first column along with the port
number of the orifice, if it is connected to a scanivalve (a pressure scanning
device that sequentially connects up to 48 pressures onto a single transducer).
The second column contains the X, Y, andZ coordinates of the orifice on the
.model. The upper right portion of the display shows the. current pressure on
the selected orifice. This pressure is updated three times each second. The
bottom half of the screen is dedicated to a graphical display of the data
gathered versus time. Each data point taken is plotted, then the best straight
line fit of the data is also plotted. The straigh~ line fit gives the
technician a good visual cue as to the rate of leakage per second. Using this
information,the technician can make a decision about the status of the orifice
and tell the program, by voice, what to record in the database. Alternatively,
if the automatic mode of operation is selected, the computer will make a decision
on the status of an orifice, record it in the database, and report its findings
to the technician.
The program maintains a database of the orifices on the model. This database
can be created manually or automatically. In the manual configuration mode,
the technician specifies the number of scanivalves, their channel numbers, and
the number of orifices connected to an Electronically Sensing Pressure (ESP) unit
(refs. 1 and 2). If the automatic configuration is chosen, the program ac~esses a
database that was created by a different program for the current model. This .
database is parsed for the information necessary to create the leak checking
program's database. At the end of the configuration the program records the
zero-pressure value for each orifice. This pressure is recorded for two
important reasons. First, in an effort to speed up the leak checking process,
knowing the zero value of each orifice allows a search mode'to be incor-
,porated in the program where the technician just applies a pressure to the
desired orifice and the program will search all orifices, stopping on the one
with the non-zero value. Without a search mode the technician needs to know the
number of the orifice he wishes to check so that it can be selected for
monitoring by the program. This can cause delays due to the technician having
to refer to the drawing to obtain the correct orifice number. The second, and
2
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perhaps more important reason for recording the zero value, revolves around the
data gathering function of the program. When the program is instructed to begin
taking data, it first checks to see if there is sufficient pressure on the
orifice being checked to perform a leak check. If there is not, it will report
this condition to the technician. This is a vitally important error check
because an orifice checked with little or no pressure on it would probably
appear to be non-leaking even if there was a leak. This could easily lead to
incorrect test results.
The system is currently configured as shown in figure 3. The only pieces of
equipment that are brought into the tunnel test section are the CRT and the
headset that the technician wears. With this arrangement, one technician can
accomplish the entire task, reducing the number of man-hours needed to perform
leak. checking on a model by a factor of three.
CONCLUDING· REMARKS
The leak checking system has been installed and tested successfully at the
l6-foot transonic tunnel at Langley Research Center. During the test, a technician
was able to perform the entire leak check of a model in the test section without
any dependence on other technicians for help. In the near future, after facility
dependent changes are made, the leak checking system will be installed at other
Langley wind tunnels. . .
REFERENCES
1. Gross, C. and Juanarena, D. B.: "A Miniature 48-'-Channel Pressure Sensor Module
Capable of In Situ Calibration," ISA 23rd International Instrumentation
Symposium, May 1977.
2. Juanarena, D. B.: "A Distributed Processing High Data Rate Multiport Wind
Tunnel Pressure Measurement System," ISA 23rd International Instrumentation
Symposium, May 1977 .
3

·'
PREVIOUS SYSTEf1 CONTROL ROOM
.~
•
SV, AND
r-------------....I---I ES P
CONTROLLEr\
..-----------_......... DAU 1-41Q-~ INTERCOMlj]
TUNNEL
INTERCOH
[i]
OPERATOR 1
- APPLIES VACUUM
OR PRESSURE
- SEALS ORIFICE
- CALLS FOR DECISION
ON LEAK RATE
OPERATOR 2
- MAINTAINS LOG OF
ORIFICE STATUS GOOD,
BAD, OR NOT CHECKED
- PROVIDES X,Y,Z
COORDINATE OF ORIFICE
FIGURE 1
CPU
.........I>ICONTROL
PANEL
CRT
OPERATOR 3
- SELECTS DESIRED PORT
- SELECTS CHANNEL FOR
DISPLAY
- MONITORS READING TO
DECIDE ON LEAK RATE
PORT =
MANUAL LEAKCHECK
#37 X=I.0
CHANNEL = *35 Y=5.37 PRESSURE= 1748
ORIFICE .= #149 Z=0
1800
1790
1780
1770
1760
1750
1740
1730
1720
1710
PRESS. B B.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
SECONDS
-, .
FIGURE 2
- .
•
or
AUTOMATED SYSTEM
OPERATOR - "SPEAKS" DESIRED ORIFICE OR COHPUTRR AUTO
SEARCHES FOR APPLIED PRESSURE
-
• • • I ,
STATUS, OR DISPLAYS ON CRT CONTROL ROOM
- MAINTAINS DATA BASE OF STATUS AND
PROVIDES REPORTS SV. AND
ESP
CONTROLLER
DAU u~ --eL1-
.....
f f
-
1-0
TUNNEL TALKER Ie,
'V ...,.--, ~~ HEADSET~.- .:::::s:--
.' :> '- ISTENER P CPU({\~COLOR
DISPLAY ) J OP.ERATOR
-- c )
COMPUTER DECIDES WHETHER LEAK RATE IS OK "SPEAKS"
FIGURE 3
,. Report No.
NASA TM-86359
I 2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
A VOICE-ACTUATED WIND TUNNEL MODEL LEAK CHECKING SYSTEM
7. Author(s)
William E. Larson
9. Performing Organization Name and Address
NASA Langley Research Center
Hampton, Virginia
12. Sponsoring Agency Name and Address
National Aeronautics and Space Administration
Washington, DC 20546
15. Supplementary Notes
5. Report Date
Fphrtlarv lQ8"
6, Performing Organization Code
992-19-00-18
8. Performing Organization Report No.
10. Work Unit No.
11. Contract or Grant No.
14. Sponsoring Agency Code
16. Abstract
A voice-actuated wind tunnel model leak checking system has been developed. The
system uses a voice recognition and. response unit to interact with the technician
along with a graphics terminal to provide the technician with visual feedback
while checking a model for leaks.
17. Key Words (Suggested by Author(sl I
Data Acquisition
Wind Tunnel Instrumentation
Voice Input/Output
18. Distribution Statement
Unclassified - Unlimited
Subject Category 01
..
r
19. Security Oassif. (of this report)
Unclassified
20. Security Classif. (of this pagel
Unclassified
21. No. of Pages
7
22. Price
A02
N·305 For sale by the National Technical Information Service. Springfield, Virginia 22161




A voice-actuated wind tunnel model leak checking system

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