NI-Based HIL Platform for Electric Bus VCU Validation

Application Summary

TMCS developed an NI-based HIL platform to validate Vehicle Control Units (VCUs) for electric buses. Using NI PXI, VeriStand, TestStand and LabVIEW, the platform runs real-time drive cycle and fault simulation, enabling automated, repeatable and traceable testing of performance, safety and diagnostics. Simulink integration supports safe virtual validation while reducing prototype use, test time and risk.
Author: TMCS Team | Theta Measurement And Control Solutions Pvt. Ltd.

CHALLENGE

An electric bus VCU works with many other ECUs, such as motor control, high-voltage battery, braking and
the instrument cluster, over the vehicle CAN network. Validating it on full-size prototype buses is costly and
slow, and testing faults and safety functions on a real vehicle is risky. The challenge was to simulate the
whole vehicle around the VCU, run complete drive cycles and fault scenarios automatically, and keep every
result traceable.

SOLUTION

TMCS delivered a real-time NI PXI platform in which NI VeriStand executes vehicle models (braking,
battery, motor/drive) and CAN messages, including models brought in from Simulink. The I/O and CAN
interfaces connect to the VCU and other ECUs, and fault insertion allows electrical and communication
faults to be injected safely. NI TestStand automates drive-cycle and fault test sequences, and LabVIEW
provides the operator interface and reporting

Test Types / Parameters Monitored

TEST TYPE	DESCRIPTION / PARAMETERS MONITORED
Drive Cycle Simulation	Runs real-time drive cycles to evaluate VCU performance
Fault Simulation	Injects electrical and CAN faults to verify safe responses
Diagnostics Validation	Checks fault detection, reporting and diagnostic behaviour
Multi-ECU Interaction	Verifies VCU communication with MCU, battery, braking and cluster ECUs
Safety Functions	Validates VCU behaviour in safety-critical scenarios

Specifications & Features

Feature	Description
Real-Time Vehicle Models	Braking, battery and motor/drive models in NI VeriStand
Simulink Integration	Reuses model-based development assets in the HIL loop
Automated Sequencing	NI TestStand executes test campaigns without manual intervention
Traceable Results	Logged data and reports for every test run
Scalable Architecture	Supports additional ECUs, I/O and networks

Technology Used

The platform integrates NI PXI real-time hardware with NI VeriStand for model execution, NI TestStand for test automation and reporting, and LabVIEW for the operator interface. Simulink models plug directly into the real-time system, and CAN and I/O interfaces with fault insertion connect the platform to the ECUs under test.

Advantage / Benefit

Less prototype dependence: much of the validation happens before buses are built.
Reduced test time and risk: faults and safety scenarios are tested virtually and safely.
Automated, repeatable and traceable: every test campaign is consistent and documented.
Model reuse: Simulink integration connects design and validation teams.
Scalable: the platform grows with new ECUs and vehicle variants.

Conclusion and Future Plan

The HIL platform provides a safe, efficient way to validate electric bus VCUs for performance, safety and diagnostics. Future enhancements may include more ECUs in the loop, additional network protocols and expanded drive-cycle and fault libraries.