Simulation Guide
Knowledge Guides /How do you choose between software-in-the-loop and hardware-in-the-loop, and when is physical hardware worthwhile?
Last updated: · New Horizon Digital Outsourcing Team
Software-in-the-loop is suited to quickly checking algorithms and interface logic. Hardware-in-the-loop further checks real controllers, communications, and timing behavior. They are not substitutes for each other: select the validation level according to current risks, rather than treating connected hardware as proof of model correctness.
Select the validation level according to risk
- While algorithm logic is still unstable, prioritize software models to broaden operating-condition coverage. Consider hardware-in-the-loop when real-time scheduling, bus latency, or real drive behavior becomes critical. List the issues each level can and cannot reveal to align testing effort with objectives.
Establish replaceable interface boundaries
- Separate control algorithms, equipment interfaces, and environment models while keeping signal semantics consistent. When replacing a simulated controller with a real one, recheck sampling rates, scaling, saturation limits, and abnormal states. Idealized software interfaces often conceal timing issues that emerge with physical hardware.
Prepare before connecting hardware
- Check that the model can run within the target cycle time and define safe timeout handling. Physical equipment integration must follow laboratory safety and authorization requirements and be confirmed by the responsible on-site person. Steps involving motion or energy output cannot be judged safe solely from a remote interface.
Acceptance requires more than a successful run
- Compare software-in-the-loop and hardware-in-the-loop logs for the same inputs, explaining timing and output differences. Deliver wiring information, protocols, versions, scenarios, and stopping conditions. Passing one in-the-loop scenario does not validate all operating conditions of the real system.