Hardware-in-the-Loop Simulation (HILS) for Avionic Test Systems - Digilogic Systems
                     H A R D WA R E - I N -T H E - L O O P  
S I M U L AT I O N
Real-time, closed-loop validation of avionics, flight control, and 
missile guidance systems — bridging simulation and hardware for 
mission-critical reliability.
Digilogic Systems  |  Engineering Real-Time Simulation & T
est Solutions
HILS for Aerospace & Defence Testing  |  Digilogic Systems 01 / 10
FOUNDATIONS
What Is Hardware-in-the-Loop Simulation?
Hardware-in-the-loop simulation (HILS) is a r
eal-time testing THE CLOSED LOOP
methodology that integrates actual physical 
hardware — such as flight control units, avionics Unit Under Test
computers, or missile guidance electronics — with Real avionics / guidance hardware
a simulated model of the surrounding system or 
Instead of relying purely on software models or 
environment. Real-Time Simulator
costly live flight/field trials, engineers validate how Models flight dynamics & sensors
real hardware responds to realistic, dynamically 
generated inputs — in real time, under repeatable I/O Interfaces
and safe laboratory conditions.
Feeds live signals both ways
Quick Answer: HILS = real hardware + real-time 
simulated environment, connected in a closed loop Result: validated hardware behavior, in 
to validate system behavior before deployment. real time, without flight risk.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 02 / 10
STRATEGIC  IMPORTANCE
Why HILS Is Critical in Modern Aerospace and 
Defence
Mission-Critical Reliability Reduced Program Risk
Flight control, avionics, and missile guidance 
Identifying integration and timing defects in 
systems must perform flawlessly — HILS 
the lab avoids costly failures during flight test 
validates behavior under both nominal and 
or, worse, in operational service.
fault conditions before fielding.
Regulatory Compliance Faster, Safer Iteration
Supports certification evidence for DO-178C Engineers test thousands of scenarios — 
software verification, DO-254 hardware including hazardous edge cases — without 
validation, and MIL-STD testing requirements. risk to aircrew, assets, or test ranges.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 03 / 10
METHODOLOG
Y
How HILS Works: The Real-Time Test Loop
1 2 3 4 5
The mRoedaell- Truime Model the Plant ns on a Hardware 
Aircraft/missile Execution
Signal Interfacing
I/O modules convert The uRnesponsedeterministic real- it under test Closed-Loop 
dynamics, sensors & time target (e.g., simulated signals (flight computer, Feedback
environment built in PXI/FPGA) at into real electrical guidance electronics) Hardware outputs feed back 
a real-time into the simulation, and microsecond-level interfaces the processes inputs results are logged, 
simulation model. timing. hardware expects. exactly as in the field. analyzed, and validated.
The entire loop executes deterministically in real time — often at kHz-level update rates — so the hardware cannot distinguish the 
simulation from reality.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 04 / 10
SYSTEM ARCHITECTURE
Key Components of a HILS Test Setup
Real-Time Simulation 
Unit Under Test (UUT) I/O & Signal Conditioning
Platform
PXI/FPGA-based deterministic Interfaces for analog, discrete, bus 
The avionics, flight control, or 
compute for plant & environment (ARINC 429, MIL-STD-1553), and RF 
guidance hardware being validated
models signals
Test Management & Data 
Modeling & Test Software Logging
Model-Based Design environments Scenario orchestration, automated 
for plant models, scenarios & test sequencing, and results 
automation reporting
HILS for Aerospace & Defence Testing  |  Digilogic Systems
05 / 10
APPL ICAT IONS
Applications in Aerospace and Defence
Flight Control Systems Missile Guidance & Navigation Avionics & Sensor Integration
Validating fly-by-wire and autopilot logic Testing guidance algorithms and seeker Verifying radar, GPS/INS, and sensor 
under realistic flight dynamics. response across engagement scenarios. fusion under simulated flight conditions.
Electronic Warfare Systems UAV & Autonomous Platforms Vehicle & Weapons Systems
Evaluating countermeasure and threat- Validating autonomy stacks and control Testing embedded controllers for ground 
response electronics safely in the lab. laws before live flight trials. vehicles and weapons platforms.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 06 / 10
VALUE  PROPOSIT ION
Benefits of HILS Over Traditional Testing Methods
Criteria Traditional Testing Hardware-in-the-Loop Simulation
Live flight/field trials carry Hazardous scenarios tested safely 
Test Safety
operational risk in the lab
Flight test hours and range time are 
Cost Lower-cost, repeatable bench-
expensive level validation
Repeatability Field conditions vary and are hard to Identical scenarios re-run 
reproduce precisely, on demand
Limited ability to inject rare failure Fault injection across a wide 
Fault Coverage
modes scenario matrix
Schedule Sequential, weather- and asset- Parallel, round-the-clock lab-
dependent testing based test cycles
HILS for Aerospace & Defence Testing  |  Digilogic Systems 07 / 10
PROVEN PRACT ICE
Industry Use Cases and Real-World Examples
Commercial & Military Flight 
Guided Weapons Programs
Control
Flight control computer validation against 
Closed-loop testing of guidance, navigation, and 
certified aircraft dynamics models, supporting 
control electronics across simulated engagement 
DO-178C software verification evidence prior to 
profiles and countermeasure environments.
flight test.
Radar & Sensor Fusion Labs UAV Autonomy Validation
Integration labs use HILS to validate sensor 
Autonomous flight control stacks are exercised 
fusion algorithms against synthetic radar, 
through thousands of simulated missions before 
GPS/INS, and electro-optical signal 
committing to live UAV flight campaigns.
environments.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 08 / 10
PARTNER SPOTL IGHT
Digilogic Systems: HILS Engineering Capabilities
Digilogic Systems designs and delivers custom Hardware-in-the-Loop Simulation platforms for aerospace and defence programs 
— from requirements and architecture through integration, validation, and long-term support.
Custom Test System Real-Time Simulation & 
Engineering Integration Validation & Certification 
Purpose-built HILS rigs tailored to PXI- and FPGA-based real-time Support
specific avionics, guidance, or Structured test procedures supporting DO-178C, platforms integrated with plant DO-254, and MIL-STD evidence needs.
platform requirements. models and I/O.
Ongoing Engineering 
Test Automation System Integration Services
Automated scenario execution, Bus, sensor, and network emulation Support
Long-term maintenance, upgrades, 
regression testing, and reporting integrated into a cohesive test 
and technical support across the 
frameworks. environment.
program lifecycle.
HILS for Aerospace & Defence Testing  |  Digilogic Systems 09 / 10
CONCLUSI
ON
Key Takeaways and Next Steps For enquiries, reach out 
to us at:
HILS enables safe, real-time, cost-effective validation of 
mission-critical hardware Hyderabad: (+91) 40 4547 
4601
Reduces development risk and improves reliability 
through early issue Bengaluru: (+91) 80 4975 
detection 6034
Supports compliance with DO-178C, DO-254, and AWdedbrseite: 
MIL-STD standards wewsw.digilogicsystems.com
HEemaad iOl: ffice
Applies across flight control, avionics, missile #in1f0o2@, 1dsigt iflloogori,c DsySsLt Aebmasc.ucso Tmech 
guidance, UAVs, and defence Park, beside DSL Virtue Mall,
 electronics Uppal, Hyderabad, Telangana-
Digilogic Systems delivers custom HILS platforms — 500039.
simulation, integration, Marketing Office
validation, and support #216, 3rd Floor, Zareen Heights, 
Varthur Road, Nagavarapalya,
C. V. Raman Nagar, Bengaluru, 
Karnataka – 560093.
www.digilogicsyste
ms.com
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HILS for Aerospace & Defence Testing  |  Digilogic Systems