Servo motor testing with pytest and Nominal Connect
Nominal Connect is streamlining hardware-in-the-loop Python tests
Test & evaluation: from manufacturing to operations
Before component parts are integrated into aircraft and vehicles, they undergo extensive testing. It’s critical to ensure every circuit board or actuator is functioning properly before being installed in an aircraft.
Test coverage in manufacturing is scaling with the complexity of today’s hardware products. And with the low-cost of cloud data storage, manufacturers are automating more tests and collecting more test data. This test data is critical - it feeds into AI optimizations such as predictive maintenance, and it helps achieve market-unlocking certifications in highly-regulated industries. No one has ever been fired for collecting too much test data.
Nowadays, Hardware-in-the-Loop (HITL) tests are often written in Python because of Python’s excellent ecosystem for test and measurement instruments. Libraries such as pyserial, python-can, pyvisa, pytest, and unittest have made HITL test and measurement accessible, fast, and low-cost.
As HITL testing continues to accelerate, there are two primary challenges:
Python scripts run directly on command lines are failure-prone and inaccessible to anyone but the test engineer who wrote the script.
Resulting test data is siloed between facilities, product life-stages, and even different measurement instruments for the same asset.
HITL testing in Python
Nominal’s desktop product, Nominal Connect, is being used by vehicle and robotics manufacturers for component tests and end-of-line tests. One customer, for example, uses Nominal Connect to test their servo motors, as shown in the recording below. The motor must pass this test before being integrated into a quadruped arm downstream (a “quadruped” is a 4 legged robot).
In this example, Connect provides a highly customizable, ergonomic UI for Python HITL tests that interacts with the servo motor controller. With Connect, any technician or manufacturing line operator can run these Python HITL tests and understand their output. The test results are automatically synched with the Nominal platform, where they can be collaboratively analyzed, visualized, and triaged.
Nominal Connect provides the first customizable Human-Machine Interface (HMI) framework on top of Python HITL scripts.† Without an HMI, these Python scripts are run directly on the command line, creating failures, inflexibility, and information siloes. For the first time, Nominal Connect is operationalizing Python HITL tests with customizable HMIs for the manufacturing line.
† In addition to Python, Nominal Connect supports sequencing HITL tests in Bash, MATLAB, and Robot Framework.
Distributed, Continuous Manufacturing
Manufacturing test data captured in Nominal Connect automatically syncs with Nominal’s cloud (or on-premises) platform. This means that an entire organization can monitor, analyze, and triage manufacturing test results in realtime – no matter how far from the manufacturing site.
For example, nuclear reactor manufacturer Antares uses Nominal Connect at headquarters to monitor tests at their remote production facility (read the Mission Brief). Nominal Connect can even be deployed at 3rd-party contract manufacturers so that test data is automatically sent back to the OEM’s Nominal platform. Nominal is the only test and evaluation platform with this vertically-integrated, edge-to-server capability.
Critically, this connectivity does not end with manufacturing. On Nominal, the HITL test data from manufacturing is stored alongside the data from the vehicle’s field tests, operating lifetime, and retirement. Several years into a vehicle’s lifetime, a part’s original performance during manufacture should be retrievable to compare to its current or end-of-life performance. Nominal is the only end-to-end test & evaluation platform ushering in this future.
Manufacturing the future
Testing should be delightful, low-friction, collaborative, ubiquitous, and insightful at every stage. At Nominal, we’re building the test & evaluation platform for all stages of a hardware product’s lifecycle - research, manufacturing, deployment, long-term operations, and retirement.
As the US scales up its manufacture of complex hardware products, exponentially more test data will be generated to support their reliability and development. This data is multi-modal: images, audio, and video are increasingly captured with every HITL test. Nominal is empowering this future for some of the US’s most advanced hardware manufacturers and operators. If you’re interested, reach out to us to discuss your test & evaluation efforts at any stage of a product life cycle.
All manufacturing lines Nominal.