Time expenditure in computer aided time studies implemented for highly mechanized forest equipment

Musat, Elena-Camelia; Apăfăian, Andrei Ioan; Ignea, G.; Ciobanu, V.; Iordache, Eugen; Derczeni, R.; Spârchez, G.; Vasilescu, Maria Magdalena; Borz, Stelian Alexandru

doi:10.15287/afr.2015.473

Cited by 12 publications

(8 citation statements)

References 9 publications

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“…DES model construction also requires a considerable amount of data, such as time elements of individual machines and their probability distributions, and it is often the case that sufficient data are not available in forest operations to make DES modeling feasible. Although modern data acquisition technologies (e.g., auto-video recording, GPS tracking, sensors) can help access operational data more easily and frequently [47][48][49], long-term field data collection is still necessary to obtain a representative sample of field operations and thus ensure quality output. Also, the large amount of random inputs in DES modeling can make it difficult to interpret the output in simple terms, especially for highly complex systems [50].…”

Section: Des Model Drawbacksmentioning

confidence: 99%

Discrete-Event Simulation of Ground-Based Timber Harvesting Operations

She

Chung

Kim

2018

Forests

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Operational studies are necessary to support production and management decisions of forest industries. A time study (TS) approach is widely used in timber harvesting operations to understand the performance of individual harvesting machines as well as the entire system. However, several limitations of the TS approach include the use of generalized utilization rates, incapability of capturing interactions among equipment, and model extrapolation in sensitivity analysis. In this study, we demonstrated the use of discrete event simulation (DES) techniques in modeling a ground-based timber harvesting system, and compared the DES results with those of the TS model developed with the same observed data. Although both TS and DES models provided similar estimation results for individual machine cycle times and productivities, the estimated machine utilization rates were somewhat different due to the difference in synthesizing machine processes in each approach. Our sensitivity analysis and model expansion to simulate a hypothetical harvesting system suggest that the DES approach may become an appropriate method for analyzing complex systems especially where interactions among different machine processes are unknown.

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Section: Des Model Drawbacksmentioning

confidence: 99%

Discrete-Event Simulation of Ground-Based Timber Harvesting Operations

She

Chung

Kim

2018

Forests

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“…Considering similar examples from 20 years ago, the efficiency of feller-bunchers in timber production has increased with the developments in forest machine technology. Furthermore, the time study analysis with the help of software can easily find the best regressors for highly mechanized forest equipment (Mușat et al 2015). It can be suggested that mechanized harvesting with a feller-buncher can be very productive; however further studies on harvesting productivity of feller-bunchers are required for optimum selection of the carrier platform and equipment.…”

Section: Discussionmentioning

confidence: 99%

Analysis of a feller-buncher productivity: a case study of whole-tree harvesting from Marmara region, Turkey

Gülci

Yüksel

Gülci

et al. 2021

AFR

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In fully mechanized forest harvesting systems, tree felling activities are mostly performed by using harvesters or feller-bunchers. In some regions of Turkey, where terrain conditions and stand characteristics are suitable, fully mechanized harvesting systems have been recently practiced by some of the logging contractors as private forest industry demands for large amounts of forest products throughout the year. Thus, performances of these newly practiced harvesting systems should be carefully analyzed in order to implement productive and cost-effective mechanized harvesting systems. In this study, productivity of whole-tree harvesting using a feller-buncher was investigated based on stand parameters including tree height, DBH, and volume. The DBH of the felled trees were divided into four classes (i.e. very small: 16-19 cm, small: 20-23 cm, medium: 24-27 cm and large: 28-31 cm) to investigate the effects of various DBH class on the time consumption of cutting stage and productivity of the feller-buncher. To estimate productivity of feller-buncher in harvesting operation, multiple linear and polynomial regressions were also developed and discussed after the interpretation of diagnostic plots. The results indicated that the average productivity of the feller-buncher was 74.96 m3 /h which was closely related with tree height (r = 0.63), DBH (r = 0.67), and volume (r = 0.67). The average moving time was the most time-consuming stage (60%), followed by cutting (29%) and bunching stages (11%). It was found that DBH classes caused statistically significant (p < 0.05) effects on the time spent on cutting stage and productivity of the feller-buncher. The cutting time and productivity increased from very small to large diameter classes, while bunching time increased from very small to small diameter and then medium diameter to large diameter classes. Polynomial regression had a positive impact on the performance of the estimation model of manually field-measured data based on the error parameters.

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“…Borz et al 2014) and it is particularly useful when the researcher presence in the field is either not possible or not advisable. For such an approach, however, the processing effort at the office has been proved to be resource intensive in some cases, depending on the complexity of the studied system, and therefore on the number of work elements within a work cycle (Musat et al 2016).…”

Section: Time Consumptionmentioning

confidence: 99%

Evaluation of an HSM 208F 14tone HVT-R2 Forwarder Prototype under Conditions of Steep-Terrain Low-Access Forests

Borz

Marcu

Cataldo

2021

Croat. j. for. eng. (Online)

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Forwarding technology is well established in use around the world but, at the same time, forwarders are expensive machines that require a good planning to ensure the sustainability of operations. In addition, forwarder market is characterized by a limited pool of customers, therefore innovation attempts may be limited compared to other product development industries. Since the steps towards a full automation of operations are still at their beginning, improvements of forwarder machines may rest in developing and integrating components that could contribute to an increased effectiveness. To respond to such challenges, the Forwarder2020 project developed innovative components that were integrated in a number of forwarder prototypes based on a market pull approach that resulted in a flexible adaptation to customer requirements and work environments. Since one of the typical work environments was that of low access forests, some components (i.e. suspended cabin and transmission system) were engineered to enable faster and safer operations and to economize fuel. As a common validation step is that of bringing field evidence on the performance improvement, this study evaluated the operational speed, productivity and fuel consumption of a forwarder prototype in conditions of a steep-terrain low-access forest. The main findings were very promising as the prototype was able to operate at significantly increased speeds and the fuel savings were evident. For an average forwarding distance of about 1.5 km, net productivity and efficiency rates were estimated at 14.4 m3/h and 0.07 h/m3, respectively. They were related to the availability of wood, and further improvement of such figures is possible by a better organization of tree felling and processing. Operational speed was affected by the condition of skid roads used for forwarding, which were harsh. During the transportation tasks developed on roads typical for forwarding, the machine was able to sustain average speeds estimated at 8 km/h. As a matter of fact, in such tasks, the dominant operational speed (almost in 100% of the cases) was higher than 5 km/h irrespective of the road condition. Hourly fuel consumption was estimated based on the time in which the engine was working and it amounted to 17.1 l/h. More importantly, by considering the forwarded payload in terms of volume and mass, the unit fuel consumption was estimated to be 1.25 l/m3 and 1.47 l/t, respectively. These results bring evidence on the performance improvement by modular innovation. In fact, such solutions could answer the challenges related to the sustainability of forest operations in low access forests.

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Time expenditure in computer aided time studies implemented for highly mechanized forest equipment

Cited by 12 publications

References 9 publications

Discrete-Event Simulation of Ground-Based Timber Harvesting Operations

Discrete-Event Simulation of Ground-Based Timber Harvesting Operations

Analysis of a feller-buncher productivity: a case study of whole-tree harvesting from Marmara region, Turkey

Evaluation of an HSM 208F 14tone HVT-R2 Forwarder Prototype under Conditions of Steep-Terrain Low-Access Forests

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