Loaders tackling the rough stuff for Volvo Construction Equipment (CE) testing - Robust and flexible data acquisition in the field, using eDAQ

Margins are being squeezed as competition intensifies in the construction equipment market. That's why vehicle manufacturers have turned product development into a finely-tuned process, building on precise and advanced measurements and tests. Volvo Construction Equipment (CE) uses HBM's SoMat eDAQ test system to help it test loader prototypes under extreme conditions.

With its proud pedigree in Sweden, Volvo Construction Equipment (CE) is renowned for its engineering expertise and the excellent driving characteristics of its loaders and dumpers. And they're working hard to stay out in front. The large development and testing center near Eskilstuna is an example of how they intend to do this.

Refining the construction equipment of the future

Lennart Skogh, test engineer and test driver for Volvo CE in Eskilstuna

This is where the loaders of the future are tested – covering finished vehicle prototypes as well as individual components in exhaustively monitored rigs in the large test lab. The prototypes are subjected to a range of scenarios either within the test lab – which has the space to reproduce most conditions in controlled circumstances – or out in the real world. The testing department for loaders keeps several hundred people busy, and is based in the test center, occupying thousands of square meters.

"We are constantly optimizing our range of nine loaders, and we are increasingly turning to field testing as a way of further refining them. Fuel consumption is receiving an awful lot of attention at the moment. We often evaluate driver behavior as a way of improving our vehicles and making them more fuel efficient," explains Lennart Skogh, test engineer and test driver for Volvo CE in Eskilstuna. He is one of the people organizing the toughest tests in which the vehicle prototypes are subjected to real-world conditions in places like quarries and gravel pits.

More field testing

SoMat eDAQ test system for mobile data acquisition

As vehicle testing increasingly moves out into the field, it is vital for the measuring equipment to stand its ground. Lennart Skogh and the 20 or so other Volvo CE test engineers use HBM's SoMat eDAQ test system for mobile data acquisition.

"We were pioneers when we started using the SoMat 2500 test system back in the 1990s. We now do all our field testing with its replacement, eDAQ. It is actually installed in the loader so it has to be able to handle the rough stuff. We use anything between ten and 200 channels for a single test, obtaining parameters like pressure, strain, temperature, position and acceleration," explains Lennart Skogh.

Easy calibration

To prepare for a test, the loader is rigged up with test equipment. The Eskilstuna instrument workshop contains all the equipment the team could possibly need. Along with some eDAQ systems, there are various sensor types, cables, GPS systems and cameras that can all be selected according to the particular test. Because the eDAQ system is usually installed in the driver's cab, it needs to be robust and unobtrusive.

"The process of calibrating sensors to the eDAQ is straightforward without compromising on flexibility and versatility. Either the sensor's calibration values can be used, or a known value can be entered – such as minimum and maximum cylinder lengths," says Lennart Skogh. "User input is not always 100% reliable. That's why I particularly like the eDAQ's ability to detect most errors and flag them up in a warning dialog. This makes the system virtually foolproof."

Finding patterns

The field tests carried out by Volvo CE's own test drivers can take anywhere between a couple of minutes to three quarters of an hour. Engineers are interested in acceleration, speed, forward and backward movements, loading and unloading in various combinations. Tests like this can accumulate up to 300 megabytes of data.

Analysis of the measured data starts immediately out in the field, using the Infield software. At this stage, the priority is to check the quality of the data.

"Evaluation software is crucial these days," says Lennart Skogh. "InField is quick and easy. The next step for us and our analysis engineers is to analyze and manipulate the test data, using either GlyphWorks or Matlab to identify patterns, extract statistics and spot differences between different drivers and their behavior. Everything we learn will later be used to improve our machines.

Keeping track

It can be a challenge to keep track of the thousands of measurements. According to Volvo CE, one of the strengths of eDAQ is that each test setup is saved in the measured data file. This means that the data and the setup can be used to recreate an identical test in future using the same calibration values, or to verify that the calibration values were correct if there was an unexpected result.

Taking account of the customer's driving behavior

Although Volvo CE uses its own experienced test drivers to test the vehicles to the limit on its own test track, longer-term testing is also carried out under the customer's normal day-to-day conditions.

"We do this as a way of verifying our own test facilities but also to find out more about different driving behavior," explains Lennart Skogh. Customer testing is based on an eDAQ installed in the customer's cab with a direct CAN bus link so it can obtain a range of readings from the vehicle components. We can process the data back at base because the eDAQ is connected by modem. That way, we can switch the system off and on and schedule various short tests."

Lennart Skogh predicts that field testing will become even more important in future.

"Data simulations are all very well but it is only when we test for real that we can be sure we get the right information about how our machines behave in different situations. Understanding how our customers drive is becoming increasingly important in product development, so I'm convinced we'll see even more field measurements in future," he says.

The challenge

To test advanced construction equipment under real-life conditions as part of the product development process, exposing the vehicle to the real rough stuff, for example in a quarry. The test system not only has to cope with extreme conditions – it also has to handle a large number of test parameters while remaining easy to calibrate. And the entire system has to occupy a small footprint in the driver's cab.

The solution

Volvo Construction Equipment uses HBM's SoMat eDAQ test system as the basis for its field measurements. This robust system is installed in prototypes of construction equipment and operates out in the field, acquiring data like pressure, strain, temperature, position and acceleration as the vehicle is loaded and unloaded and moved around. Around ten channels are used for testing, but as many as 200 may be needed in some cases.

The result

The SoMat eDAQ used by Volvo CE is a robust, reliable and flexible test system that sits unobtrusively in the driver's cab while loaders are being tested. The system can obtain data from a large number of channels, and the integrated modem means they can be remotely operated in order to analyze the customer's day-to-day driving.

Once the large volume of data has been analyzed, the results are used as a basis for developing the fuel-efficient loaders of the future, with improved driving characteristics and greater sustainability.

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