Kinematic Control of Redundant Knuckle Booms

Löfgren, Björn; Wikander, Jan

doi:10.1080/14942119.2009.10702572

Cited by 13 publications

(7 citation statements)

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“…General strengths and weaknesses of automatic data gathering in forest-work studies, which naturally also apply to our study, have been discussed in detail by, for example, Väätäinen et al (2003), Nuutinen (2013) and Manner (2015). Meanwhile, study-specific weaknesses are addressed in the paragraphs below.…”

Section: Discussionmentioning

confidence: 99%

“…Consequently, modelling unloading time, including all the factors affecting it, is complex. Unloading-drive distance can be considered as a control variable for unloading work, as both disadvantageous load structure and placement of (load-specific) assortment-piles far apart from each other lead to a substantial amount of driving at the landing, hence increasing Unloading-drive distance (Manner et al 2013;Manner 2015). Covariates were used if they significantly contributed to the model, were considered logical, and there was no risk of them being confounded with treatment effects.…”

Section: Statistical Modelsmentioning

confidence: 99%

“…The development of boom-tip control for forestry applications began as early as the 1980s (Löfgren 1989;Löfgren et al 1994;Löfgren and Wikander 2009). The steering principles of CBC and IBC are described in Section 2.1.…”

Section: Introductionmentioning

confidence: 99%

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Comparing forwarder boom-control systems based on an automatically recorded follow-up dataset

Manner¹,

Mörk²,

Englund³

2019

Silva Fenn.

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Highlights• Boom-tip control saves time compared to the conventional system. • This study introduced a field-study design enabling establishment of causal relationships during ordinary forwarding operations. • Although the study design requires some extra arrangements, it efficiently combines the representativeness of conventional follow-up datasets with establishment of causal relationships that traditionally have been possible only through observational time studies or standardized experiments. AbstractCrane work is the most time-consuming work element in forwarding. Hence, assist systems like boom-tip control are of interest. The first commercially available boom-tip control for forwarders was introduced in 2013. In this study we analysed whether replacing conventional boom control (CBC) with John Deere's version of boom-tip control (named Intelligent Boom Control, IBC), increases crane-work productivity. We used data automatically gathered from 10 final-felling stands, covering typical logging conditions for southern, central and northern Sweden. Two John Deere 1510E and two John Deere 1910G forwarders were operated by seven experienced operators during the follow-up study, covering 1238 loads in total. A split-plot design was applied to isolate effects of the boom-control system being used (CBC, IBC). We found that using IBC for loading work (crane work and driving included) saved 5.2% of productive machine time compared to using CBC (p ≤ 0.05). The corresponding saving when using IBC for unloading work was 7.9% (p ≤ 0.05). Depending on geophysical factors, this corresponds to approximately 4% savings in productive machine time for forwarding as a whole, including pure transport (with and without load). Moreover, the study introduced in cut-to-length context a novel field-study design to collect a large follow-up dataset in the course of ordinary forwarding operations. We found the study design to be a cost-efficient way to combine the representativeness of conventional follow-up datasets with the ability to establish causal relationships. Establishment of causal relationships has traditionally been possible only through observational time studies or standardized experiments. Silva Fennica vol. 53 no. 2 article id 10161 · Manner et al. · Comparing forwarder boom-control systems based …

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Section: Discussionmentioning

confidence: 99%

Section: Statistical Modelsmentioning

confidence: 99%

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Comparing forwarder boom-control systems based on an automatically recorded follow-up dataset

Manner¹,

Mörk²,

Englund³

2019

Silva Fenn.

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“…Studying the possibilities of the automation of these work operations has therefore become a subject of interest since the late 1980s and early 1990s. Löfgren, Wikander (2009) studied the kinematic driving strategy in order to achieve the maximum lifting capacity suitable for PC-controlled hinged hydraulic cranes. Lindroos et al (2015) analyzed various sensing technologies to estimate the harvester head position and discussed their pros and cons with respect to potential applications, accuracy and costs.…”

Section: Introductionmentioning

confidence: 99%

Influence of Intelligent Boom Control in Forwarders on Performance of Operators

Zemánek

Fiľo

2021

Croat. j. for. eng. (Online)

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This paper deals with the influence of an Intelligent Boom Control (IBC) in forwarders on the work of operators. The work with the IBC and standard system of crane control was measured by the use of a John Deere harvester and forwarder simulator. Two individuals without any practical training and two individuals with experience in the control of the crane took the measurements. The monitoring included eight different performance indicators. The use of the IBC system allowed the untrained operators to increase their work output by 27. With the use of the IBC system, these individuals also showed 53% fewer direct damages to the machine. However, our findings show that the length of experience influenced the performance of the operators out of all the monitored indicators. Notwithstanding that fact, the use of the IBC system has a direct positive influence on the economy of the machine operation.

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“…IBC is now offered as an option on all John Deere forwarders, but the development of boom tip control began as early as the 1980s (e.g. Löfgren 1989;Löfgren et al 1994;Löfgren and Wikander 2009). IBC is claimed to increase productivity and accelerate learning curves for beginner-level operators (John Deere 2013).…”

Section: Introductionmentioning

confidence: 99%

Forwarder crane’s boom tip control system and beginner-level operators

Manner¹,

Gelin²,

Mörk³

et al. 2017

Silva Fenn.

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Highlights• Boom tip control (BTC) allows the operator to control boom tip movements directly, instead of controlling each movement separately to achieve the desired boom tip movement.• BTC eased boom control, so beginner-level operators using BTC achieved higher productivity than beginner-level operators using a conventional (reference) system. • There were no significant differences in the slopes of learning curves between the systems. AbstractThe forwarder loads processed wood and transports it to a landing. Productivity of forwarding could be improved by increasing driving speed, but difficult forest terrain limits this. According to current literature, crane work is the most time-consuming work element of forwarding, so improving crane work productivity is essential for improving forwarding productivity. One way to do this is through automation of recurrent boom movement patterns, or alternatively automation can be used to ease crane work. When using conventional boom control (CBC), the operator manually controls each of the independent boom joint movements and combines them to achieve a desired boom tip movement, but boom tip control (BTC) allows the operator to control boom tip movements directly. The objective of the present study was to examine whether BTC facilitates crane work and affects the slopes of learning curves for beginner-level forwarder operators. The study was carried out using a standardised test routine to evaluate effects of two fixed factors, system (levels: CBC, BTC) and point of time (four levels), on five dependent variables. Four of the five dependent variables measured ease of boom control and the fifth measured crane work productivity. The results showed that there were no significant differences in the slopes of learning curves between the systems but the BTC did increase crane work productivity and made boom control easier.

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Kinematic Control of Redundant Knuckle Booms

Cited by 13 publications

References 13 publications

Comparing forwarder boom-control systems based on an automatically recorded follow-up dataset

Comparing forwarder boom-control systems based on an automatically recorded follow-up dataset

Influence of Intelligent Boom Control in Forwarders on Performance of Operators

Forwarder crane’s boom tip control system and beginner-level operators

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