Using rollers and stencils to draw turn arrows and crosswalk stripes on roads seems a bit archaic to MnDOT District 3 Maintenance Superintendent Randy Reznicek, who asked researchers if they could develop an automated road message painter.
University of Minnesota-Duluth Associate Professor Ryan Rosandich has taken that vision and created an robotic arm that can spray-paint pavement signs, with the goal of saving crews time and keeping them safer.
Designed to be mounted to the front of a maintenance vehicle, the robot is operated remotely by a laptop, programmed with numerous types of messages.
In an earlier prototype, researchers developed a trailer painter that could be pulled behind a truck.
Crews currently use heavy, eight-foot by four-foot stencils and rollers to paint designs, with an estimated 75 percent of such work involving the repainting of existing markings.
“It takes two people to lift the stencils,” explained MnDOT maintenance worker Joe Gilk, whom Reznicek presented with the idea about five years ago. “This would eliminate one position. One person could just run the truck and you could use that other person in another area of our job.”
Rosandich, who heads the Mechanical and Industrial Engineering Department at the University of Minnesota-Duluth, led the initial development of a software system and trailer painter.
MnDOT has funded further research to develop the more technically difficult robotic arm, which it anticipates could be used in other aspects of maintenance work as well.
Rosandich recently demonstrated the mechanical arm to a MnDOT road crew (no paint was used during the demonstration), but additional software and mechanical tweaks remain before researchers take the machine out for final testing on the pavement this spring.
A companion vision system is being developed to identify existing markings to guide the robot in the repainting of existing messages.
The robot’s three-segmented aluminum shell arm is capable of painting up to a 12-foot wide lane and has enough battery power for a whole day’s worth of work, Rosandich said.
Once the prototype is complete, researchers hope to find a manufacturer to develop and produce a machine that could be used by maintenance crews across the state. MnDOT has already had great success in deploying automated pavement patching systems in some districts.
Not only would a robotic message painter free up maintenance crews and speed up sign-painting, but Rosandich sees worker safety as its “biggest selling point.”
The start-up cost for manufacturing such a device is estimated to be $150,000.