Automation and Robotics in Forest Harvesting Operations: Identifying Near-Term Opportunities

Technology development, in terms of both capability and cost-effective integration, is moving at a fast pace. While advanced robotic systems are already commonplace in controlled workspaces such as factories, the use of remote controlled or autonomous machines in more complex environments, such as for forest operations, is in its infancy. There is little doubt autonomous machinery will play an important role in forest operations in the future. Many machine functions already have the support of automation, and the implementation of remote control of the machine where an operator can operate a piece of equipment, typically in clear line-of sight, at least is commonly available. Teleoperation is where the operator works from a virtual environment with live video and audio feedback from the machine. Since teleoperation provides a similar operator experience to working in the machine, it is relatively easy for an operator to use teleoperation. Autonomous systems are defined by being able to perform certain functions without direct control of a human operator. This paper presents opportunities for remote control, teleoperated machines in forest operations and presents examples of existing developments and ideas from both forestry and other industries. It identified the extraction phase of harvesting as the most logical placement of autonomous machines in the near-term. The authors recognise that, as with all emerging technologies and sectors, there is ample scope for differences in opinions as to what will be commercially successful in the future

Including Exogenous Factors in the Evaluation of Harvesting Crew Technical Efficiency using a Multi-Step Data Envelopment Analysis Procedure

The performance of a harvesting crew in terms of its ability to transform inputs into outputs is influenced by discretionary factors within the unit’s control, such as the selection of machines and operators. However, factors associated with the operating environment, such as terrain slope and tree size that are outside the direct control of management, can also influence harvesting system efficiency. Using data on forest harvesting operations in New Zealand, this paper applies an established four-stage Data Envelopment Analysis (DEA) procedure to estimate the managerial efficiency of independent forest harvesting contractors, while taking into account the influence of the operating environment. The performance of 67 harvesting contractors is evaluated using seven inputs, one output (system productivity) and three operating environment factors in an input-oriented, variable return to scale DEA. The results show that the operating environment including terrain slope, log sorts and piece size influence the efficient use of inputs by harvesting contractors. A significant difference is observed between the mean managerial efficiency of the crews before and after controlling for the influence of the operating environment, the latter being higher by 11%. This study provides evidence that without accounting for the influence of the operating environment, the resulting DEA efficiency estimates will be biased; the performance of crews in favourable operating environment would be overestimated and those in unfavourable environment underestimated

Analyses of Parameters Affecting Helicopter Timber Extraction

In the last 25 years, helicopter extraction of timber has developed as an important harvesting alternative in mountainous areas. Typical helicopter operations include the extraction of valuable timber from stands with inadequate road networks, large areas of difficult to reach wind-throw, and sensitive sites where the negative impact on soil and water must be minimized. An empirical study provides information on the effect of silvicultural treatment and pilot experience on the productivity of the K-Max helicopter. The productivity model is a function of the average stem piece size, the horizontal distance between stump and landing, the silvicultural treatment, and the experience of the pilot. The productivity obtained when harvesting from a clear-cut was greater than from the `femel-cut' (patch-cut) extraction site by 0.20 m3/min, or 21% at an average piece size of 1.5 m3. The inexperienced helicopter pilot had timber extraction experience but just 30 flight hours on the K-Max while the experienced pilot had 22,000 K-Max flight hours. The experienced pilot yielded a 0.37 m3/min increase in productivity, which is a 63% increase at an average piece size of 1.5 m3. This indicates that operator experience on a particular machine may be very important when comparing harvesting systems based on time studies

An Applied Hardwood Value Recovery Study in the Appalachian Region of Virginia and West Virginia

An analysis of log-making (bucking) performance for five logging crews in southern Appalachian mixed-hardwood stands of Virginia and West Virginia was conducted. Cutting accuracy and value recovery were analyzed and compared to an optimal solution that was determined through the use of the HW-BUCK computer software. In total 148 trees were bucked into 510 logs and only 11 percent were cut accurately. Fifteen percent were under cut and 74 percent were over length. The crew with the best performance in length cutting accuracy also recorded the lowest value recovery loss. An average value loss of 20.7 percent was calculated for all five crews

Cable Extraction of Harvester-Felled Thinnings: An Austrian Case Study

A time study of the cable extraction of thinnings in short corridors was carried out in the Neuberg an der Mürz forest area, Austria. Both the yarder and the choker-setter(s) were studied. Six options were compared. For the "standard" option the timber was felled, cut to length, and pre-bunched by the harvester on a 20-meter-wide corridor, and was yarded downhill. Two choker-setters were employed. The five variations included: (1) "larger" bundles, (2) in-creased lateral hauling distance, (3) one choker-setter, (4) the harvester cutting-to-stem length and the timber yarded uphill with only one choker setter, and (5) trees in a 30-meter-wide corridor felled and bucked by motor-manual methods. The harvester used was a Skogsjan 687 XL with a 601 head; the medium-sized yarder was a Syncrofalke with a Sherpa U3 carriage. The time study results showed that the corridors felled and cut to length by the harvester, in comparison to the motor-manually cut corridor, provided a significant improvement in the cable extraction cycle times: 3.7 min compared to 4.6 min. Additionally, an average turn volume increase of 26% was achieved by the improved presentation of the timber. A 20-meter lateral-hauling distance increased the cycle time by only 7%. The use of one choker-setter increased the delay-free cycle time by just 10%, however it significantly decreased the work-related waiting time for the choker-setter to just 5%. Uphill stem extraction using one choker-setter had the same cycle time as the downhill cut-to-length extraction using two choker-setters, although a 5% greater average turn volume was recorded

A Decade of Benchmarking Harvesting Cost and Productivity

The FGR harvesting cost and productivity benchmarking database was expanded by 97 new entries from harvesting operations in 2018. The average ground-based logging rate increased to $28.35/t, up$1.55 compared to 2017 data. Ground-based logging rates ranged from $17.60/tonne for a highly mechanised grapple skidder operation, through to$49.50/t for a mechanised felling/forwarder combination working in a difficult windthrow setting. For cable logging the average rate was $41.25/t, which was$1.85/t higher than the previous year. The level of mechanised felling has continued to increase for cable logging operations, now used in 40% of operations. An additional 17 entries were recorded where felling was supported by winch-assist, with all but four in cable yarder operations. Based on 2018 data the average logging rate for the winch-assist operations was $1.25/t lower than other mechanised felling cable operations. This might in part reflect the increased productivity of winch-assist operations as the industry becomes more experienced with its implementation

Developing an Automated Monitoring System for Cable Yarding Systems

Cable yarders are often the preferred harvesting system when extracting trees on steep terrain. While the practice of cable logging is well established, productivity is dependent on many stand and terrain variables. Being able to continuously monitor a cable yarder operation would provide the opportunity not only to manage and improve the system, but also to study the effect on operations in different conditions. This paper presents the results of an automated monitoring system that was developed and tested on a series of cable yarder operations. The system is based on the installation of a Geographical Navigation Satellite System (GNSS) onto the carriage, coupled with a data-logging unit and a data analysis program. The analysis program includes a set of algorithms able to transform the raw carriage movement data into detailed timing elements. Outputs include basic aspects such as average extraction distance, average inhaul and outhaul carriage speed, but is also able to distinguish number of cycles, cycle time, as well as break the cycles into its distinct elements of outhaul, hook, inhaul and unhook. The system was tested in eight locations; four in thinning operations in Italy and four clear-cut operations in New Zealand, using three different rigging configuration of motorized slackpulling, motorized grapple and North Bend. At all locations, a manual time and motion study was completed for comparison to the data produced by the newly developed automated system. Results showed that the system was able to identify 98% of the 369 cycles measured. The 8 cycles not detected were directly attributed to the loss of GNSS signal at two Italian sites with tree cover. For the remaining 361 cycles, the difference in gross cycle time was less than 1% and the overall accuracy for the separate elements of the cycle was less than 3% when considered at the rigging system level. The study showed that the data analyses system developed can readily convert GNSS data of the carriage movement into information useful for monitoring and studying cable yarding operations

Forest Machinery Fires: Trends in New Zealand Forest Harvesting Sector

Fires in forest machines are typically catastrophic in terms of machine destruction and can develop rapidly to be a risk to the machine operator. They are an issue worldwide and there can be larger consequences such as starting a major forest fire. This paper describes trends in machine fire occurrences in the New Zealand forest harvesting sector. A total of 224 machinery fire incidents were recorded over an 8 year period from 2007 to 2014. Trends in forest machinery fires in the sector were identified and summarized. Late morning (10 am-noon) and mid-afternoon (2–4 pm) showed the highest incidence of machine fire, corresponding to periods with the highest level of work. Excluding the main holiday months, there was a correlation of machine fires to average monthly temperature. Summary statistics on causes of fire ignition showed that 40% were attributed to electrical and hydraulic faults; however, some remain unidentified as the fires commenced after work was completed. A short survey of industry managers was carried out to ascertain machine fire perceptions. 67% agreed that machine fire was an issue, and only 33% thought the current industry procedures were sufficient to mitigate them. The report concludes with proactive measures to reduce the incidence of forest machine fire risk

How to market and harvest your forest woodlot for profit

This booklet is aimed at woodlot owners who are close to the harvesting stage of their woodlot operation. It is not a manual for the establishment and management of woodlots. Nor is it a textbook for logging contractors on how to carry out their business. This booklet attempts to provide you, the woodlot owner, with sufficient information to help you successfully manage the marketing and harvesting of your woodlot