Autonomous pruning: the future of forest management

Autonomous pruning: the future of forest management

The findings of a new report into the current state of autonomous pruning equipment, both in Australia and overseas, have given confidence to plantation managers around the future potential of these technologies. 

With anticipated future innovations, this type of technology could be used to support bushfire risk management, improve the economic value of the nation’s timber resource, and overcome occupational health and safety risks.

The recently completed report, A review of current mechanical & robotic tree pruning equipment, was developed by the University of the Sunshine Coast’s Forest Research Institute (FRI) and international research partners.

“In recent years, increased interest has been expressed by Australian plantation forest managers in the potential use of mechanical or robotic tree pruning systems,” said lead author Mark Brown, Professor of Forestry Operations at USC and Director of the Forest Industry Research Centre, who led the review.

“Meanwhile, Australian researchers agree there could be potential value in importing and testing specific commercial solutions, or even designing and developing specific solutions domestically.”

Before committing to significant financial investment in this space, FWPA commissioned an independent global review of mechanical tree pruning technologies currently being used in plantation forest management, as well as the prospective development of future technologies both domestically and internationally.

A technical desktop review was used to inform the report, alongside a review of academic literature published in the last five years and industry journals published in the last two years.

Information was collected on each identified system of interest, covering capabilities and performance, while considering stem and branch size, height, tree age, species, trees per hour and the impact of gradient.

Equipment was also compared for technological readiness, capital and operating costs, range of application, and the general strengths and weaknesses for potential use in the Australian setting.

“While the mechanics of these inventions have improved, the agility and range of application are still limited, in particular when applied to radiata pines,” said co-author of the report Dr Sam Van Holsbeeck, a research fellow at the University of the Sunshine Coast who worked closely with Brown on the review.

The report highlighted issues with early robotic pruning systems, such as the Sachs Tree Monkey, including the equipment’s weight, agility, range of application, and capacity to move along whorls and cut large branches on stems.

“The heaviness makes equipment unattractive for use on young trees, or to be carried by forest workers, particularly in steep or rough terrain. Often the equipment needs to be carried by two or more people, and still results in physical strain on the body,” Van Holsbeeck said.

However, the researchers identified trends indicating likely upcoming improvements and investments. These include the more recently developed technologies such as PATAS, Unmanned Ariel Vehicle (UAV)-based pruning, and futuristic stick insect-inspired robots.

“The PATAS manufacturer noted that rough bark increased the performance of the system, that performance is dependent on-site conditions and is potentially higher in plantations, and that further developments are underway,” said Van Holsbeeck.

“More recent technologies such as UAV’s and the stick insect-inspired robots also show promise. Their remote control and access to rugged terrain, as well as some high-performance artificial intelligence in terms of branch detection and automated tree measurements, are attractive attributes.

“However, these technologies still need to overcome several technical and operational challenges to become operational and commercial.”

The findings of the report will be used to inform decisions around future Australian R&D investment in this space.

The full report can be found by visiting https://www.fwpa.com.au/resources/reports/resources/2420-a-review-of-current-mechanical-robotic-tree-pruning-equipment.html