Hardware-in-the-Loop Testing for Embedded Valve Control

Developing a HIL platform that connects a physical ESP32-C6 controller to a valve emulator on NI ELVIS III. The project investigates command sequencing, fault handling and timing through physical digital I/O, controlled fault injection and experimental evaluation.

Discipline: EMBEDDED SYSTEMS / HARDWARE-IN-THE-LOOP / VALVE CONTROL
Course: TPK4560 — Robotics and Automation, Specialization Project
Project type: academic
Period: Autumn 2026 — ongoing
Evidence: Project summary
My role: Test platform development and controller testing

01 / Engineering challenge

The system behind the project

This ongoing 15-credit specialisation project at NTNU is supervised by Amund Skavhaug. It asks how accurately and repeatably a HIL platform can reproduce defined valve behaviour and faults, and how effectively it can verify the controller's sequencing, timeout and fault-handling logic. The work is motivated by verification challenges in industrial automation and subsea control systems, where access to physical equipment can make fault testing difficult. The valve model is a generic benchmark with defined experimental assumptions; it does not represent a validated commercial subsea actuator.

02 / My responsibility

What I personally worked on

My work covers controller firmware in C using ESP-IDF and FreeRTOS, physical I/O integration, the LabVIEW valve model, fault-injection design and experimental planning. I am now developing automated tests and structured data collection to evaluate controller behaviour and the timing and repeatability of the test platform.

Engineering focus

— Hardware-in-the-loop testing
— State machines, sequencing and timeouts
— Fault injection and requirements-based testing
— Timing measurements and repeatability

Tools and methods

Embedded CESP-IDFFreeRTOSLabVIEWESP32-C6NI ELVIS IIIDigital I/OTimestamped logging

03 / Design and implementation

From concept to working system

01
Run C firmware on an ESP32-C6 using ESP-IDF and FreeRTOS. Separate tasks handle user commands and valve-control logic, with commands passed through a queue.
02
Use a state machine with UNKNOWN, CLOSED, OPENING, OPEN, CLOSING and FAULT states. Monitor movement timeouts and contradictory feedback; a latched FAULT state sets both movement outputs LOW and rejects further movement requests.
03
Run a simplified valve model in LabVIEW on the NI ELVIS III real-time processor. Configurable constant-speed movement updates a bounded position, while a stuck-valve condition freezes movement.
04
Connect the controller and emulator through two digital movement commands and two end-position signals. Record timestamped command and status messages, with an initial software test mode for artificial feedback during firmware development.

04 / Testing and outcome

What the work demonstrated

The initial prototype has demonstrated normal opening and closing and a stuck-valve scenario. Physical I/O exchange, queue-based command handling, the valve state machine, movement timeout and contradictory-feedback detection are implemented. These demonstrations establish basic functionality. Systematic evaluation against predefined requirements, including measurements of reaction time, model-update timing, signal-generation delays and repeatability, remains in progress.

05 / Next iteration

Next steps in the project

1Develop requirements-based tests for normal operation, stuck and slow movement, missing feedback, contradictory feedback and plausible but incorrect position indications.
2Automate test sequences and collect an experimental dataset linking each test condition to the observed controller response.
3Measure event-to-response time, actual model-update timing and signal-generation delays, then assess variation across repeated runs.
4Document detection limits: a blocked valve and a failed end-position sensor can produce the same observations when only two end-position signals are available.
5Produce a reproducible test procedure and scientific report documenting the platform's capabilities, limitations and results against the requirements.