Clearing block cave drawbell hang ups robotically

Penguin Automated Systems has shipped what is thought to be the world’s first hangup assessment and clearing robotic system to Codelco’s Andina mine in Chile. The robot hangup clearance unit features an arm that extends 4.6 m horizontally and 10 m vertically through the throat of a drawbell in a block cave mine. At the end of the arm are a 3D camera, an infrared lighting system, a drill and an explosives loader.

The robot scans the inside of the drawbell and creates a virtual map of the hangup, explains Penguin CEO Greg Baiden. The system collects point cloud data and transfers it into a gaming engine that allows an operator in a specially adapted Normet RBO personnel carrier a safe distance away to optimise the position of the arm, drill a hole, load an explosives charge and remotely clear the blockage.

The robotic system built for Codelco could be the first of many more units given the growing number of block cave mines around the world and the importance of coming up with a way to clear blockages without exposing miners to unnecessary risk.

Of the estimated 200,000 drawbells in the world, up to 10% of them are blocked at any one time, said Baiden.

The robot uses a military positioning system that allows for the adjustment of the pitch, roll and yaw of the machine, which in turn allows the operator to precisely guide the robotic arm through the throat to the blockage. “It’s probably one of the most sophisticated robotic arms ever built,” said Baiden. “There are 20-plus patents in it.”

An optical communication system provides the bandwidth necessary to gather the point cloud information and transmit it back to the robot in real time. Optical receivers on each side of the robot absorb the light from LEDs and convert it to a different format so it can be digitised.

“Typically, optical signals have to be point-to-point and aimed right on line, which would have been a problem, but we developed a way to collect the optical information in a 70-m hemisphere all around the receiver,” said Baiden.

One of the challenges Penguin designers had to overcome was how to open and extend the arm to its full extent within the limited confines of an underground drift. The problem was overcome by designing it to telescope out horizontally and then vertically with support for the vertical part of the arm provided by a stinger that extends down to the ground. In overcoming this as well as other challenges, Penguin worked closely with Codelco’s Hector Cerda, who heads up innovation, and Juan Sanchez, a senior operations engineer at Andina.

The robot is an all-electric, battery-powered machine. It operates without emissions and so quietly that Codelco wanted it equipped with beepers and lights so it could warn underground personnel of its approach, said Baiden.

Pan-tilt-zoom cameras with spritzers and windshield wiper blades to keep the lenses clean are installed on each corner of the robot to provide the operator with situational awareness.

Penguin is working with a mining equipment manufacturer to market the robots worldwide, but has committed to building the electronics and robotics in Sudbury, Canada.

According to Baiden, there are several other potential applications for a robot with these capabilities – in sublevel cave mines and ore passes, as well as for explosives dismantling, environmental disaster response, or cleanup and remediation work at a nuclear power plant like Fukushima in Japan – where the Penguin robot can access and perform complex tasks without putting people at risk.