Engineering Test Rig

CAREER EPISODE 3 –
ENGINEERING TEST STATION FOR AVIONIC UNITS

SUBMITTED TO:
ENGINEERS AUSTRALIA

PREPARED BY:
VIJAYANANDA D MOHIRE
Bachelor of Engineering (Electronics and Communication)

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CE 3. 1 INTRODUCTION .................................................................................... 5
CE 3.1.1 PROJECT DURATION...................................................................... 5
CE 3.1.2 PROJECT LOCATION ...................................................................... 5
CE 3.1.3 NAME OF INSTITUTE ..................................................................... 5
CE 3.1.4 MY ROLE............................................................................................ 5
CE 3.2 BACKGROUND ........................................................................................ 6
CE 3.2.1 AIMS & OBJECTIVES OF THE PROJECT ..................................... 6
CE 3.2.2 METHODOLOGY ............................................................................. 7
CE 3.3 PERSONAL ENGINEERING ACTIVITIES............................................ 7
CE 3.3.1 ANALYSIS OF DFCC ........................................................................ 7
CE 3.3.2 ANALYSIS OF ETS ........................................................................... 8
CE 3.3.3 DESIGN OF HARWARE AND SOFTWARE INTERFACES ........ 9
CE 3.3.4 MY TECHNIQUES AND STRATEGIES ....................................... 10
CE 3.4 SUMMARY ............................................................................................. 11

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Document control

Distribution list
NAME ROLE REPRESENTING
Engineers Australia

Amendment record
VERSION DATE STATUS COMMENT
0.1 2-May-09 Draft Prepared by Vijayananda
D Mohire

Document statistics
VERSION NUMBER OF PAGES NUMBER OF WORDS NUMBER OF LINES
0.1 11 1742 347

Disclaimer:
The technical material contained in this document is provided for information
purpose only and the author does not guarantee implicitly or explicitly the
accuracy of the information provided. However, best effort has been made to
provide accurate information. Logos, trademarks and brand names, if any, used in
this document are exclusive property of their respective owners.

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Declaration:

„All statements of fact in this report are true and correct and I have made claims of
acquired competencies in good faith.

The report is all my own work and is a true representation of my personal
competence in written English. I confirm that I understand that members of the
engineering team in Australia are required to display a commitment to exercising
professional and ethical responsibility in all aspects of their work.

I also understand that documentation submitted in support of my application may
be referred to the Department of Immigration and Citizenship (DIAC) for integrity
checking.‟

Printed Name:

Signature:

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CAREER EPISODE 3

ENGINEERING TEST STATION FOR AVIONIC UNITS

CE 3. 1 INTRODUCTION

CE 3.1.1 PROJECT DURATION

The project started in June 1996 and was completed by Jan 2000. This
project was basically carried out in order to provide ground clearance of
aviation equipments like Navigator units, Digital Flight Control computer,
and quadruple fly by wire communication devices.

CE 3.1.2 PROJECT LOCATION

The project was carried out in Light combat Aircraft (LCA) hanger and
Aircraft Research and Design Center. The campus is located in Bangalore,
Karnataka state, India.

CE 3.1.3 NAME OF INSTITUTE

Hindustan Aeronautics Ltd. is a central government undertaking under
the Defense Research and Development Organization (DRDO). It is
located in Bangalore city, Karnataka state, India

CE 3.1.4 MY ROLE

I joined on Contract and based on my performance I was inducted in role
of Assistant Engineer for this project. I reported to Deputy Manager, who
was also our guide for this project. I had to interact with a large group of
Scientist both local and from overseas.

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CE 3.2 BACKGROUND

I am placed in this
hierarchy as
Project /Assistant
Engineer
Figure 1: Organizational chart

CE 3.2.1 AIMS & OBJECTIVES OF THE PROJECT
 Study and Identify the existing systems and devices in hand
 Identify the gaps needed to execute the current test cases
 Design and develop missing electronic interfaces to the Flight control
systems – hardware and software
 To develop suitable Low level programming meant for capture of
instruction set from the Microprocessor

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 To interfaces relevant external devices and toolkits for measuring
digital avionic parameters like airspeed, vector velocity, angle of attack
etc..
 To develop unit and integration test cases based on Defence standards
 To do testing on actual devices using real and simulated software and
other COTS products

CE 3.2.2 METHODOLOGY
 Analysis of the existing testing platform – hardware and software
 Design new interfaces using electrical and electronic devices
 Interface with Electromechnical switches and actuators
 Design and develop Low level code using C and Ada to either
simulate or extract data from the MIL-1553B bus.
 Mount the test devices in proper orientation – roll pitch and yaw
 Run the test cases under simulated conditions of varying flight
parameters
 Confirm the behavior of the devices and tabulate the same
 Report the observations
 Provide clearance to the incoming devices that need to be on
boarded to the actual aircraft.
 Repeat the procedures for different devices

CE 3.3 PERSONAL ENGINEERING ACTIVITIES

CE 3.3.1 ANALYSIS OF DFCC

I had to read operating manuals and attend session classes related to the
DFCC and avionic industry standards.

I was able to identify and summarise the finding in short:
The DFCC is an Intel 80960 μC-based 32-bit quad redundant computer
having a throughput of 2 MIPS (1750 digital avionics instructions per
second equivalent). The cross-channel data links transfer data across the
four channels at 2 MBPS. Over 512 parameters are exchanged for
redundancy management. The I/O interface consists of 256 channels of
12-bit ADCs (analog to digital converter) and 32 channels of
12-bit DACs (digital to analog) with full scale accuracies of not less than
99.81 per cent and redundant high performance RS422 and MIL 1553B
links to the rest of aircraft avionics and instrumentation. The DFCC has a
fault detection capability of more than 95 per cent and has a proven
reliability of 5235 hours MTBF.

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CE 3.3.2 ANALYSIS OF ETS

I had to attend training sessions and get familiarize with the ETS. Also I
had to identify the interface requirements and what all external and
internal dependencies exist. In short I was able to summarize about the
ETS.

This is a multi -processor-based realtime, automatic/manual test station
used for the functional verification of FCS. Engineering test station (ETS)
provides capability to simulate, stimulate, monitor and generate failure
for all the inputs/outputs of the DFCC. The ETS is used for acceptance
testing and real-time hardware/software integration of the DFCC, system
integration, and testing of the LCA-FCS. It can replace some or all
simulated sensors and actuators with real hardware. Also, the ETS
interfaces with the mini-bird and iron-bird test facilities to monitor the
DFCC performance during closed-loop testing, pilot-in-the-loop testing,
interface calibration, end-to-end dynamic testing and FCS verification and
validation.

Figure 2: ETS and Mini Bird setup

The functional architecture I defined using Structured Analysis and
Design Technique (SADT). I had to follow to follow Ward and Mellor
DFD methodology. C and Ada languages were used as both design and
code language. The software I developed and documentation broadly
followed the MIL-STD-2167A standard. The software has been categorised
as a computer software configurable item (CSCI) that executes on the
hardware configurable item (HWCI). I had to work on the above defined
principles and standards.

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CE 3.3.3 DESIGN OF HARWARE AND SOFTWARE INTERFACES

 I designed and developed new circuit for proper power supply
of the Navigator unit. I used the standard input and designed a
mini board using electronic switches, rectifiers and power
devices with power supply health indicators.
 I interfaced Data Device Corporation (DDC) chipset onto the
external board using flat ribbon cables, RS232 serial
communication cables.
 I developed low level code to capture and change the Timer
settings in terms of nano seconds.
 I wrote interrupt sub routine for different interfaces
 I captured data from the RAM using suitable addressable
memory, and made them persist onto archived files.
 I conducted the routine “Happy scenario” mode of operations,
changed the external parameters and unit mounting positions
and conducted several rounds of testing.
 I tabulated the readings and provided a copy to the reporting
manager

One sample working scenario of the card was as Bus controller mode. I
interfaced the required Pins of the chip and wrote code to run the card
as Bus Controller and provide the controller settings to other
terminals. Suitable data was coded in the data block and sent across to
other terminals that would then take the commands and data.

Figure 3: DDC chip in Bus controller mode

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Below provides equipments used in one sample validation scenario

Sl.No Equipment Purpose
1 Connection Panel This provides the equivalent
functions of bus couplers, networks,
terminators and cables required for
test configurations.
2 1553 Bus Tester Acts as external data monitoring
Oscilloscope, devices
True RMS
Voltmeter,
Impedance
Analyzer
3 The 1553 Noise provides band-limited
Generator white Gaussian noise required for
noise rejection testing
of terminals designed to MIL-STD-
1553
Table 1: Validation equipments

Sl. Parameter Normal values Recorded values
No
1 Vpp value [V] 18.0-27.0 18
2 Sync waveform - 100-300 150
Tr value [nsec]
3 Data bit 100-300 150
waveform - Tr
value [nsec]
Table 2: Sample report

CE 3.3.4 MY TECHNIQUES AND STRATEGIES

 I adapted to the new environment that was quiet different from the
academic world. This I did by observing carefully my seniors, their
reporting orders, and their break times etc.
 I overcame few challenges like not making myself restricted to
ideas and suggestions and at times I did advise changes in electrical
wiring diagrams as it did not obey the laws of electricity.
 I had to start off without any help at times when I was on different
shift and I did this by taking Knowledge transfer of staff on duty
previous day.

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 I used the official diary to record day to day works and that helped
me recollect for any earlier issues that needed solution today.
 I got involved in a collaborative manner during Integration testing
with other team members and had to trust on their efforts in
delivering the results.
 I attended technical review meetings scheduled weekly to report
and understand the progress of work. This needed me to be
actively involved in the operations and provided me an opening to
communicate effectively and seek help for any issues.
 I learnt a lot from senior scientist and overseas defense contractors
who were working on the actual aircraft. I had to manage the
language and accent they were speaking and had to respond
properly.
 I learnt ways to reducing risks of failure due to human errors and
report for any faulty operations immediately

CE 3.4 SUMMARY
My responsibility of design and implementation of the interfaces and
testing of the avionic devices using ETS was completed successfully. This
provided me the confidence to work on live projects and take on more
responsibility of the same. I had good experience working of different
engineering fields like Electrical, Mechanical and Instrumentation as
relevant to Avionics.
Also this was a project I started off my career with the working
knowledge in a Public sector and an opportunity to work hands on an
aircraft.

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