Operated by a crew member positioned in an above-ground office at Boliden’s Kankberg underground mine, the wheel loader performed loading tasks in a production atmosphere while researchers examined remote-control-to-machine communication concerns such as network delays.
Safety was Boliden’s primary driver in participating in the research, says Fredrik Kauma, Boliden project manager. “The best way to avoid accidents is to take the operator away from a dangerous situation,” Kauma says. “We believe remote control is a critical component of removing the human element from the production face.”
At Boliden, wheel loaders typically load and move ore. “It’s crucial that remote control not hamper the flexibility of the loader. While remote control has been around in some form since the 1980s, it was pre-programmed. Not all of our loader work is planned, and we wanted the operator to use the machine as if he were inside the actual cab.”
Boliden sees other benefits to remote-controlled loaders at the mine face. It increases an operator’s quality of life, since he or she is working in an office environment instead of underground. This also might help the company recruit future operators. And there are possible production upsides, since there would be no need to wait to ventilate an area after blasting. “You could send the loader in early,” Kauma says.
No more line-of-sight
In a typical remote control process, the operator keeps the machine he’s controlling in sight.
In the Volvo/Boliden test, the operator is connected to the machine via the internet. During the test, researchers tested the controls using both standard Wi-Fi and 4G+ networks.
The remote-controlled loader used 16 diffused lights and six cameras, three facing forward and three on the rear of the machine. An inertial measurement unit transmitted machine motion to the above-ground control station, which featured seven screens, one for each camera, and an additional screen that gave information on such functions as machine articulation, bucket tilt angle, cylinder pressures, etc. “We turned down the machine’s vibration and rocking at the control station, but we still felt it was important for the operator to feel the machine,” says Erik Uhlin, Volvo’s advanced engineering program leader.
During the test, an operator sat in the underground loader as a safety measure. “But we never needed to use them,” Kauma says.
The research revealed some challenges. “Since we’re real-time streaming, it puts stresses on our dedicated internal network,” Kauma says. “It’s critical that the delay between the above-ground controls and the machine be minimal. Since the operator is in an office environment, he loses feeling of the machine, and he needs to know if he’s stressing the machine.”
Volvo says it wants to prove remote control technology is applicable in a challenging application. “Industrial applications in mobile networks aren’t just something out of science fiction – they’re real,” Uhlin says.
Uhlin calls the project “a great success,” giving Volvo and its partners the ability to showcase a more efficient, safer future underground mine. Kauma goes one step further: “Our mine manager asked when it would be available for sale.”
The remote control project offers an interesting peak at future loader design, such as what happens to when you take away the cab. “You could make a machine more energy efficient without the weight of the cab, and you could lift material more vertically,” Uhlin says.
The Volvo/Boliden tests are part of a “Pilot for Industrial Mobile Communication in Mining” project, and also involves communications network giant Ericsson, phone company Telia, robotics firm ABB, applied research institute RISE SIC and Lulea University Technology.
No timeline was discussed for future development of the remote-controlled loader.