Create test software for a one-time duration test of a high-voltage, high-current automotive product. Full functionality was necessary within 5 days while test rack hardware was concurrently developed.
National Instruments LabVIEW with client-supplied hardware including MagnaPower high voltage supply, Neslab heater/chiller, and Wago Kontakttechnik digital I/O.
During the development of a new product, or perhaps the troubleshooting of unanticipated field failures, an endurance test may be completed to obtain data on performance over a long period. Tests are often executed only once or twice. While high confidence in the measurement is critical, the budget of such a system is generally minimal.
The client required a 1,000 hour test of a high-voltage, high-current automotive component. The challenges were numerous. Testing needed to start 5 days from the client request. Test software would be completed by Tecnova using National Instruments LabVIEW while the test rack would be assembled concurrently using in-house client resources – leaving no time for shakedown of the test solution. Failure of the test component could be catastrophic (i.e., destruction, fire). The tester must run unmonitored on a 24/7 basis, yet to reduce cost, software was to execute in a Windows environment (instead of an embedded platform). Since Windows may crash at some point during testing, the test must restart from the last recorded data point.
The software application uses a Producer-Consumer State Machine design pattern. Functional Globals are used to encapsulate instrument drivers. The system controls temperature of heating/coolant flow to the test component and cycles power to the device. Voltage, current, temperature, and heating/coolant flow are monitored continuously and logged at periodic intervals.
Error handling was necessary since the unit was to run overnight. However, cost/time constraints limited development options to a basic error handler for simple shutdown of the process and prompting of the operator that a shutdown had occurred. This provided the needed level of safety but did not allow for automated attempts at recovery.
Project coordination was key, and there were few issues despite the obstacles. The test allowed our client to complete their testing with logged data as proof that the test was completed and passed.