When the rubber hits the road

Automated control systems modified for weight-based road marking vehicles eliminate mistakes for customers

In the road marking industry, competitiveness among private contractors is intense. Vying for regional and local projects with rigorous specifications, contractors work hard to gain a competitive edge. Implementing strategies that help achieve specification requirements and reduce mistakes can vastly improve profitability and the likelihood of winning future contracts.

Historically, operation of vehicles involved in the painting, maintenance and construction of public roads has been largely manual. Changes in paint spray levels and the width and length of highway divider lines required adjustments by hand, with the vehicle at a full stop. The paint needs to be mixed with precise amounts of fine, sand-like glass beads to make divider lines more visible and increase light reflectivity for nighttime drivers. Using these manual systems, mixtures were often left to the least reliable measurement method – guesswork. For years, road maintenance experts told Jeff Wilkens, owner of Industrial Automation Supply (IAS) in Fargo, N.D., that cost-effectively automating road-marking vehicles was impossible.

A major focus for the IAS control systems business is the area of road automation machinery, or RAM lines, used to automate many of the manually operated parts of road-construction vehicle – including road-marking trucks. The RAM equipment is manufactured by ITW Safe Zone and IAS then provides the control system. Generally, IAS packages its control systems, a technology patented by M7 Monitoring Systems, and sends them to end users with installation instructions, or sends them to manufacturers that install IAS-built equipment in road construction vehicles.

Challenge

Challenges associated with manual labour can be one of the biggest problems for contractors that submit bids to win lucrative government road projects. Because work conditions can be demanding, achieving strong employee retention and productivity can be difficult. Because roadwork in areas with harsh winters is nearly always seasonal, projects must generally be completed in a five- to six-month time frame during the spring and summer.

Profits can be made or lost depending on the results of seasonal labour and heavy equipment working in tandem. In road-marking applications, contractors are often forced to repaint lines at their expense if the paint reflectivity isn’t up to specification. In such a situation, combined labour and paint costs can easily reach $10,000 per mistake. Painting trucks with mostly manual components can be so imprecise that repainting can sometimes be required several times during a single project.

Sensing a tremendous, untapped opportunity to improve an entire industry, Wilkens sought to create a programmable controller-based system that would completely automate road maintenance vehicles and provide highly precise on-road performance.

Solution

With the goal of creating completely automated road construction vehicles, Wilkens went directly to Rockwell Automation for a suite of control products to achieve his vision. Wilkens cites several years of previous experience with the company as the key reason behind his decision to rely on Rockwell Automation.

“We went with Rockwell because they had the product depth I was looking for, and I believe they have the best support channel of any automation manufacturer around today,” Wilkens says. “We wanted to make these trucks mini factories on the road by completely automating the truck. Using automation, we can give a flexible and cost-effective way to improve the process of how road paint is applied.”

Working with local Rockwell Automation senior channel sales engineer Bruce Penas and the area distributor, Border States Electric, Wilkens arranged brainstorming sessions to select the components necessary to create the IAS paint monitoring system.

After the sessions, Wilkens decided that the programmable controller-based system would use HMI software and bring the field inputs into the system using the DeviceNet platform. Allen-Bradley MicroLogix 1500 programmable controllers and RSView Machine Edition (ME) software running on a 6182 industrial computer were chosen for viewing the HMI in the cab of the paint truck. For systems that can be operated by remote control, the team chose PanelView screens for the operator interface. DeviceNet is used for the controller chassis scanner card and provides an open network that can seamlessly integrate other components – including components from other companies.

“We needed a rugged method of gathering data from the various sensors around the vehicles while taking electrical noise and vibration into account,” Penas says. “We went with DeviceNet specifically because we had to develop a system that travels down the road, as opposed to a fixed, mounted control panel. In such an environment, noise immunity and flexibility were vital.”

Today, IAS assembles all of the controls, panels and the equipment required to automate road construction vehicles. The IAS paint monitoring system mixes paint with glass beads at a constant ratio that delivers optimum reflectivity. The system can tell what the ratio is in five- or 10-foot increments, because the system tracks distance as well as current feet-per-gallon and pound-of-bead-per-gallon. Operators can automatically make adjustments on the fly by altering the pressure or speed to get the proper mixture ratio. Despite this paradigm shift for the truck operators, just three days of training are required to learn how to operate the control system.

Results

IAS customers have enjoyed numerous instances of substantial cost savings from usage of the paint monitoring system. One end user discovered that a large order of paint that was purchased previously was several hundred gallons short. Making the case using data from the IAS automated system, the end user was able to deduct more than $50,000 from the total paint bill.

“Our company effectively has 100 percent of the market share for our area because we are filling a void that was left completely unfilled,” Wilkens says. “No one else was offering an automated weight-based road-marking system. Going from zero sales when we started in 1999, we have achieved approximately $7.5 million in sales in 2003, and we expect healthy growth for years to come. We essentially started with a shovel and, with the help of Rockwell Automation, made a road marking machine that accurately and automatically does all the things that, in the past, required lengthy work stoppages and yielded weaker results.”

IAS now builds approximately 20 paint-monitoring systems and 120 to 140 RAM control systems per year and has been involved in improving the road construction fleets of several U.S. state Departments of Transportation (DOTs). IAS has even had an impact on the road marking specifications. If contractors want to work in certain states, they must have a control system like the ones developed by IAS for M7 Monitoring Systems.