Electronic efficiency: road construction equipment update

The road building equipment sector is becoming increasingly competitive and manufacturers are trying to differentiate themselves by developing electronic control systems to increase machine productivity and operator comfort.

The development of electronic systems used in road building equipment has been rapid in the last decade. As technology progresses these systems are becoming more sophisticated, easing labour for the operator and increasing machine productivity and efficiency. They also make machines easier to use.

Richard Owen, vice president for Volvo's road building division in Europe, told iC, Volvo's ABG paver range is fitted with a CAN-Bus electronic control system. "The heart of that and the main thing which most benefits the operator and the customer is the operator control system," he added.

He explained the Electronic Paver Management (EPM) system allows the operator to control machine functions by pressing buttons that refer to pictures of the relevant machine parts. He added there are two separate parts to the control system - the planned view of the paver and a display screen which gives additional information like the engine oil temperature, the water temperature and the engine speed.

Electronic evolution

Mr Owen said there has been "fairly intensive development" of this system in the last decade and a full colour, second generation Electronic Paver Management system - the EPM2 is now available.

"One of the important things here is that we provide information to the operator if he needs it. Mr Owen said. "It's simple to operate at a basic level but if the operator needs or wants more information then that's available too."

The company believes the easier it is for the operator to work on the machine the less likely he is to make a mistake, which in turn saves the contractor money.

He added, "In a modern age it is absolutely necessary for the contractor to operate fault free. The penalties for laying a defective asphalt mat are quite extreme and are getting worse."

Meanwhile, Volvo's electronic compaction measuring device is vital to ensure contractors have compacted correctly in each section of the jobsite, Mr Owen said. It also allows them to record the fact that they have achieved the correct levels of compaction, which is important proof for site inspections. Other manufacturers have systems that measure the level of compaction and automatically adjust the compaction performance/compaction output, he added.

"Our vibration system has two fixed levels of performance. But basically we fix the compaction output from the drum, we then measure the level of compaction but by doing that we are leaving the operator in control of the compaction system itself. We are not varying it automatically," he explained.

Meanwhile, John Irvine, vice president, sales and marketing for US-based Roadtec said the company steers away from CAN-Bus systems.

"We know other manufacturers are moving in that direction but our customer base is telling us they want something that works every day and that they can fix in the field," he said. "They don't want to have to go and get computers replaced, have back up computer systems or be in the software business," he added.

The company has hardwired all its pavers, milling machines and material transfer vehicles (MTVs), and despite this costing more to manufacture, "if problems occur the machine is much easier to fix in the field," Mr Irvine said.

Other compaction optimisation systems available include Hamm's Hammtronic system for its compactors. Automatic adjustment of the front and rear drive prevents a spinning of the drum or wheels and allows a gradeability of up to 70%, and the system also manages all engine and roller functions, in particular drive, vibration, oscillation and engine speed. The vibration system and the driving speed are adapted by the electronic engine management to the respective operating conditions. All information is transmitted to the information display and this documents the most current data.

Dynapac's Compaction Analyzer for asphalt (DCA-A) helps operators achieve the ideal rolling pattern by keeping track of the number of passes and showing temperatures in the asphalt. Bomag's measuring and documentation system, meanwhile, detects and logs not only the stiffness but also controls and documents the compaction process, the number passes, the amplitude, the frequency and the working speed, as well as asphalt compaction and asphalt temperature.

The ErgoPlus paver handling system from Vögele focuses on the operator, the company said. It encompasses the operator platform, the operator's control desk and the screwman's lateral console on the screed, the new Niveltronic Plus for automated grade and slope control and a well-thought-out service concept, Vögele said. All vital paving and paver functions are controlled via push-buttons on the control desk and there are four different operating modes available: Neutral, Job Site Mode, Positioning Mode and Pave Mode.

Next generation

Manufacturers are constantly developing new ways to improve the technical capabilities of electronic controls.

Mr Irvine said the next generation will have more add-on features that will plug into grade and slope controls.

"I would hope at some point that we could measure the smoothness of the road being laid behind the mat and also tie it into the system in real-time - so not only could you measure thermal imaging behind the mat but also measure the actual smoothness that you are achieving so you could make adjustments on the fly," he explained.

Mr Owen said automatically linking GPS into a paver control system would become very beneficial because of the quality assurance issues and the financial penalties of not achieving the right compaction results.

Operator comfort

Improving the operator's working environment is also crucial for enhancing productivity in road building equipment.

Mr Owen said, "A comfortable operator will be more productive and on the paving side particularly, the more comfortable he is the better he is able to concentrate on the job in hand and the less likely he is to make mistakes."

The EPM system is easy to position, he added, so the operator has an ergonomic working position both in terms of operating the controls and visibility around the machine.

Meanwhile, Mr Irvine said, "In our environment it's hot - you have a 350°F (175°) mix and we are hopeful that with the popularity of warm mix it will be more comfortable for the paver operator in the future."

Using warm mix technology means operators unload mix at about 240 to 270°F (116 to 132 °C) instead of 275 to 300°F (135 to 150°C).

He added Roadtec has lowered the deck height on its pavers so the operator can communicate more easily to the workers on the ground and introducing asphalt fume collection systems have also been important for improving operator comfort. "By using a fume collection system it makes it about 10°F cooler for the operator and the screed man," Mr Irvine said.

Outlook

The global road building sector, like the rest of the construction industry, is facing an uncertain future - although some territories are less affected by the economic crisis than others.

Manufacturers must remain focused on improving operator comfort and machine productivity in order to remain competitive in increasingly challenging market conditions.

Electronic control systems are key to improving machine performance. "There is a whole generation of customer and contractor who grew up with electronics and expect and demand those kinds of features on the machinery," Mr Owen said.

With regards operator comfort he added the big challenge for Volvo is to improve operator comfort to the standard that the company's customers expect, "which I think is a standard that the road building industry hasn't seen before...the bar is set very high," he said.