Production Testing Case Studies

To confirm PULSE's suitability in Production line testing, here are a couple of case studies showing PULSE™ in action. In each case, the software was modified out of house, further confirming PULSE's credentials as an open system.

The Austrian Connection
Brüel & Kjær Austria has developed several production test systems for customers, mainly automotive sub-suppliers. Working with an external software developer, they have used both their sound and vibration expertise and a good deal of creativity to develop systems for testing products as diverse as electric motors in electric door mirrors to sintered (ceramic) articles for car engines. All of their systems use a PULSE™ unit to serve more than one production line, reducing system costs. A feature of these systems is the extent to which Brüel & Kjær have gone to produce a thoroughly developed product that incorporates customers' wishes.

One of the systems is in operation with Magna Auteca, an Austrian subsidiary of Magna International, a Canadian automotive sub-supplier. A single PULSE™ system is used to control four independent test stations on production lines being used for the manufacture of car electric-door mirrors. Testing is done using a vibration transducer with a specially developed probe system for measuring the vibration generated by the mirror motor in operation. The system measures the cepstrum of the vibration signal and compares it with a tolerance mask giving a pass or fail indication via a series of red, green and yellow lights. This information is sent via floating contacts to the existing QC system.

The system is password protected with normal users only able to observe the results and supervisors having permission to set tolerance masks. The complete system is monitored. In the event of system failure, fail-safe mechanisms are activated to ensure no part leaves the factory unchecked.

North America
In North America a slightly different approach has been used. Here, a whole new PULSE application has been developed called the Production Test Advisor (PTA). PULSE™ and the PTA combine to form the PULSE™ Production Test System (PPTS). What the PTA brings is flexibility; you can set your own evaluation criteria (what is to be measured and the pass/fail criteria) and interface with the production controller.

The PPTS is configurable for multi-product production lines, and will identify the product coming down the line using any of a variety of inputs, such as from a bar- code reader or programmable logic controller. With the product identified, the PPTS will then perform the appropriate test and pass on the pass/fail information to the system controller via a relay interface.

As with other PULSE™ based test systems, the PPTS can be made available as a turnkey solution. These systems are now being used across North America. The PTA software fully utilizes the power of the PULSE™ analyzer, thus allowing it’s use in a wide range of industries. The PULSE™ Production Test System is currently used in the automotive industry to test transmissions, transfer cases, alternators, super chargers, electric seats and AC systems. It is used in the Appliance industry to test refrigerators, dishwashers and components. The multi-analysis capabilities of the PULSE™ system allows multiple analysis techniques to be performed simultaneous in real time and the PTA software tolerances each data set and saves the data to a database. In addition to providing a pass or fail, the PTA software provides a reject ID thus identifying the nature of the fault. The PTA software also has a wide range of statistical tools built in to allow quickly setting tolerances based on the statistics of acquired data and statistical tools to check limits and monitor production distributions.