Robots are coming to a forest near you
Stung by workplace accidents and deaths, the forestry industry is hoping robots will soon take over the most dangerous jobs. Will Harvie reports.
No worker on the slope, no hand on the chainsaw.’’ That was the theme of a recent research project funded by the New Zealand forestry industry and Government to reduce accidents and deaths in our forests.
While funding has ended for one aspect, it’s still a long-term goal and university researchers such as Dr Rien Visser, director of studies in forest engineering at the University of Canterbury, foresees autonomous felling machines, robot trucks delivering logs to mills and drones replanting forests – eventually and maybe.
While other researchers are looking deep into robotic tree fellers, Visser believes robotic chainsaws are some time away – and there’s lower hanging fruit to tackle first.
He also doesn’t foresee robots with humanoid features – two legs, two arms and perhaps a head – clomping through New Zealand forests, as fun or frightening as that might be.
Forestry robots will be wheeled or tracked vehicles – uncool, but high-tech industrial beasts built to survive the steepest terrains, festooned with video cameras, connected to the internet cloud, but still overseen by a human. Think of big bulldozers, without a cab for human control.
Visser, in a public lecture earlier this month that marked his promotion as a full professor, said mechanisation of the forestry industry had already come to New Zealand.
There are fewer hands on chainsaws and more big machines felling and processing trees, especially on flat land.
Once they are cut, logs have to be extracted from the forest floor to a cleared, flat area called a ‘‘landing’’.
Log extraction is the most promising aspect of autonomous forestry, Visser says. In a January report he wrote for Forest and Wood Products Australia, Visser called it the ‘‘most realistic’’ area for autonomous development. These days, machines called skidders and forwarders driven by humans are used for extraction on flat and rolling terrain.
Extraction is predictable but sometimes dangerous work,
Visser says. Autonomous machines could work on relatively well-defined trails in the forest. They don’t need to think much, just move along the trail back and forth, extracting logs to the landing.
‘‘However, for such extraction systems to become productive and cost effective, [they] need to be able to self-load and unload,’’ Visser wrote in the Australian report.
In other words, robots need to be able to identify the trees or logs in the forest, know how to pick them up, and stack them.
He thought autonomous extraction technology was a ‘‘nearfuture opportunity’’, one to five years away.
Agriculture is already leading the way with this. Driverless machines have been developed to harvest wheat fields, for example. Guided by GPS, they drive simple, straight lines back and forth.
Alternatively, a human drives the harvester but the tractor pulling the grain cart is driverless and positions itself with 5cm accuracy with GPS, radar and lasers. It’s called ‘‘precision agriculture’’ and Visser says the technology is mature.
Similar technology is used at airports: Driverless shuttle buses drive strict routes with predictable hazards and stops.
Once logs have been extracted to the landing, they need to be processed, and this is another near future opportunity for automation, Visser says. Work on landings is dangerous because it mixes humans, heavy machinery and logs. It can also be monotonous and workers are exposed to the weather.
Systems exist that can autonomously scan logs and make judgments about length and quality. The next step is for robotic systems that can cut, sort and load them.
The Forest Growers Research has a proposal before funders at the moment for work on such a conveyor belt system, says Russell Dale, R&D manager at Forest Growers Research, the applied science arm of the Forest Growers Association. The association harvests about 80 per cent of the annual take and is funded by a levy on cut trees.
Dale also recognises the need for more steep-slope harvesting and operations research. These are the country’s most dangerous forestry workplaces.
The risks – falling trees, chainsaws themselves, large moving machines – are exacerbated on steep slopes. Some of hills being harvested are 50 degrees.
On steep slopes, there are still hands on chainsaws, although fewer than in recent years, says Dale.
For extraction on steep slopes, ‘‘cable yarding systems’’ are used. They are something like ski or tourist gondolas and lift bunches of logs from the ground and convey them through the air to the landing.
But there are still problems, most notably that humans, called choker-setters, are still sometimes needed to wrap chains around logs, or bunches of logs, before they can be extracted.
Grapples – essentially giant claws – have been developed in New Zealand and elsewhere to pick up logs. Grapples can move humans some distance away from the dangerous logs and chains.
In some cases, the operator is working the grapple with remote control systems. Sometimes a spotter is needed to help the remote controller to ‘‘see’’ the logs.
A relatively recent innovation, already successfully marketed overseas, are video camera systems on these grapple systems.
Meanwhile, New Zealand companies have developed systems that anchor bulldozers or excavators at the top of hills and use winches to help move and stabilise heavy machinery.
They are moving up and down the hill along straight lines. When a line is cleared of logs, the set-up is moved sideways along the slope and re-deployed. This allows machines to fell and help extract trees on all but our most steep and difficult slopes, says Visser.
This work on steep slopes is also ripe for automation.
Longer term, thoughts turn to autonomous trucks hauling logs to mills. Forestry may be able to adopt this technology fast as it can be used on dedicated (private) forestry roads from which civilians are banned.
There’s also talk of drones shooting saplings into the ground in reforesting operations.
This may be needed because the new Government wants to plant a billion trees over the next 10 years and we don’t have the workforce to plant that many by hand, Visser says.
One particularly cool development is a radio-controlled tree-to-tree swinging harvester.
A prototype was built by Scion – the Crown Research Institute specialising in trees and wood – and Canterbury mechanical engineering and mechatronic students.
One claw grips a tree while another claw reaches out to grip another tree. It can then release the first tree, swing to a third tree and grip it. The machine would not touch the ground and could operate in steep or rough conditions.
A chainsaw would have to be developed that can be carried by this tree-to-tree swinging harvester.
Both Dale and Visser acknowledge that mechanisation and eventually robotics have and will affect jobs.
But some former cutters are now operating big machines, they say. And there will always be work maintaining machines – keeping hydraulics working, engines tuned and so forth.
However, if New Zealand is smart, we’ll be the ones designing and building the robots, adding high-quality jobs to regional manufacturing, says Visser.