Noise and vibration tester hits production line

Version 5.0 of the Plato system offers a number of new features which enhance the ease of setup and extend the scope of noise and vibration testing of vehicle assemblies in the production environment.

Version 5.0 of the successful Plato system from Anthony Best Dynamics (ABD) offers a number of new features which enhance the ease of setup and extend the scope of noise and vibration testing of vehicle transmissions, engines and power-steering assemblies in the production environment.

End of line noise testing of powertrain assemblies and other components including rotating shafts in vehicles has been well established since the mid-1980s - as well as being hugely influential drivers of in-vehicle subjective impressions, noise and vibration responses are also indicators of manufacturing or assembly errors that can produce warranty issues and affect service life.

Although the Windows-based Plato v5.0 is ideally suited for the production environment, the system is also designed for offline analysis of data in the laboratory and in R and D work and provides an excellent correlation between test stand and in-vehicle noise assessments.

A new aspect of Plato v5.0 is a production mode window, which provides all of the information required by the operator during the entire production cycle.

At the top and left-hand side of this window are status panels providing clear indications to the operator of Plato's current status and position in the test cycle.

There are certain stages in any given test cycle and the status panels are updated to reflect transitions between these stages, alerting the operator to any problems/errors the system finds during the course of a test.

Also, as the production test progresses, it creates a series of tabbed windows that are conveniently organised into easily accessible groups.

Any window can then be inspected after the test should this be required.

Like its predecessors, Plato v5.0 offers an Explorer-like project tree that allows the user to easily organise their data specific to the testing/analysis of particular products.

Ease of setup is enhanced by exploiting the concept of "variant configurations" to provide a way of breaking up the test to be performed in a series of smaller tests relating to the same product in a number of different operational configurations (for example, discrete ratios in a transmission).

The new test template area provided by Plato v5.0 is available to define procedures to be carried out on a range of essentially similar products.

Simple menus allow the user to either create or delete test template areas according to their needs.

Production testing in Plato v5.0 is based on the ability to define the actual product under test with the Plato Project as well as the test schedule to be performed on the product.

In Plato v5.0, these two areas of definition are broken into two parts.

Test templates are used to define how the product will be tested and which processes will be carried out on it.

Data capture, processing and grading etc.

is defined within test templates for each variant configuration defined.

These settings may well be applicable to a range of products and are therefore considered to be generic settings.

There is also a requirement to define properties which are particular to each individual type of product being tested.

These variant specific settings are defined in a new project item named a production variant.

The production variant has properties that are used to define how the product is viewed from within Plato as well as to the outside world (for example the test stand).

Identification strings are set up for each production variant to inform the system of what product is being tested and variant specific properties such as key expected orders are defined here.

This two-sided approach to defining the product being tested and the tests to be performed allows a great deal of common test setup information to be shared between a number of Production Variants thereby greatly reducing the Plato setup time and effort.

An additional new feature in Plato v5.0 is the speed check action, which has many functions, including monitoring speed and ADC channels and ratio checking.

The action can be set up to stop once a particular speed has been reached (accelerating or decelerating).

A diagnostic tool has also been provided for interactive use to display on-the-fly ramp rates - useful for commissioning systems and verifying commissioning setups in the future.

The display options in Plato have been extended in Version 5.0 with a grade percentage histogram view added to the grade trend view.

The view wizard guides the user through a sequence of pages to collect the information needed to create the summary grade view.

When this is completed, a new view window will appear in the view area on the right of the screen.

This view consists of two tabs.

The graph tab displays the data graphically and, depending on the graph type chosen, a trend or the new histogram will be displayed.

In common with all Plato views, the text tab displays a table of the plotted values from the graph.

Plato is a variable-speed multichannel order locked analysis system that, unlike other systems on the market, is based on the use of multiple sensor channels (noise and/or vibration and/or torque fluctuation).

Arrays of microphones are often specified and spatial averaging of these channels has proven to provide reliable and robust data, even in manufacturing environments.

Channel averaging in this way improves the repeatability of the measurements and ensures that results are not unduly "coloured" by individual sensor positioning.

In Plato, measurements can also be taken across a speed range to ensure that all operational speeds are covered.

The current trend, especially in the car industry, is to make suppliers responsible for larger and larger subassemblies, of increasing complexity.

Hence the need for comprehensive end of line testing for noise and vibration such as that provided by the Plato v5.0 system is likely to increase, because suppliers and automotive OEMs will not be able to risk the consequences of rejection by the end user.

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