Multi-Channel Motor Control — Firmware Tested Without the Motors¶

The drives and their sensors, simulated as the counterpart — so multi-axis motor firmware is validated at the desk and on every commit, instead of on heavy-load test benches.

Industry: Manufacturer of mechatronic devices with multi-channel motor control (several drives per controller).

The challenge¶

Motor-control firmware has to react to what the drives actually do — currents, positions, end-stops. Validating it used to mean the real thing on the bench: motors, heavy-load fixtures, and a full drive cycle for every test run.

Each drive cycle is slow, and the rig is bulky and awkward to handle.
Units are tested one after another, rarely in parallel.
Corner cases, load and stress scenarios eat even more manual bench time.

The result was a validation loop measured in hours and gated by physical hardware.

The LoopCheck solution¶

A test board adapted to the controller stands in for the drives and their sensor feedback. A motor model runs in real time — microsecond time steps — on the test controller, and the customer's MCU is wired in through its real interfaces and run against that model.

A LoopCheck adapter board configured for drive and sensor emulation

Drive simulation — current profile and mechanical behavior are tuned by parameter, not by swapping hardware.
Driven from Python — parameters and load torques are set at runtime; the suite runs automatically on every commit.
Owned by the customer — they add their own test logic on top and have built their own operating GUI.

Reproducing the messy parts¶

What makes motor firmware hard to test is the non-ideal behavior — and that is exactly what the counterpart reproduces deterministically, and what the customer can extend at will: end-stop variants and mechanical stops, the current profile within the PWM phase matched to real inductance and parasitic effects, hard load changes, mechanical backlash and non-ideal pulse encoders.

Tested interfaces (counterpart)¶

High-level overview of what the counterpart emulates and measures:

Motor drives (H-bridge PWM) with per-drive current sensing
Position feedback (quadrature encoders and analog)
Additional application-specific PWM signals
Digital and analog I/O, plus serial links, for the surrounding control signals

Result¶

Development desk

Tested at the development desk instead of on real drive hardware.
Parallel

Several units under test at once, instead of serially.
CI/CD

Automated test runs on every commit.