Grzegorz Szewczyk, Raffaele Spinelli, Natascia Magagnotti, Paweł Tylek, Janusz M. Sowa, Piotr Rudy, Dominika Gaj-Gielarowiec. (2020). The mental workload of harvester operators working in steep terrain conditions. Silva Fennica vol. 54 no. 3 article id 10355. https://doi.org/10.14214/sf.10355

Keywords: logging; ergonomics; eye tracking; fatigue; gaze behaviour

Highlights: We analysed a harvester operator’s perception of his work environment as slope gradient increased; Increasingly difficult work conditions (steeper terrain) were reflected by increased eyeball activity; Fixation duration increased with slope gradient, while the duration of saccades was shorter; Variation of the eyeball movement cycles was also related to work difficulty caused by slope gradient.

Abstract | Full text in HTML | Full text in PDF | Author Info

The use of modern multi-functional forestry machines has already been associated with central nervous system fatigue induced by high mental workload. As these machines are being used under increasingly difficult terrain conditions, further knowledge is required on the expected aggravation of operators’ mental workload, so that suitable work/rest schedules can be developed. Within such a context, the aim of this study was to gauge aggravations of mental workload derived from increasing slope gradient. Measurements of eye activity were obtained from a representative harvester operator working in corridors with the following mean inclinations: 9%, 23% and 47%. The duration, frequency and trajectory of eye movements were used to determine the harvester operator’s mental workload, on the assumption that worsening work conditions would be reflected by increased eyeball activity. The number of fixations during the performance of all tasks increased with the increasing slope gradient. Similarly, fixation duration increased with slope gradient. The mean duration of saccades when working on a 23% slope was 5% shorter compared to work under a 9% gradient. A further significant shortening of saccade duration (~22%) occurred when working on a 47% slope. The good match between eye activity cycles and work cycles, visible especially on steep slopes, indicates that mental workload is related to work conditions. Overall, operating a forest harvester on steep slopes results in a greatly increased mental workload and calls for suitable rest schedules.

Szewczyk, University of Agriculture in Krakow; al. 29 Listopada 46, 31-425 Kraków, Poland E-mail: rlszewcz@cyf-kr.edu.pl
Spinelli, National Research Council of Italy, Firenze, via Madonna del Piano, 10 50019 – Sesto Fiorentino, Italy E-mail: spinelli@ivalsa.cnr.it
Magagnotti, National Research Council of Italy, Firenze, via Madonna del Piano, 10 50019 – Sesto Fiorentino, Italy E-mail: natascia.magagnotti@ibe.cnr.it
Tylek, University of Agriculture in Krakow; al. 29 Listopada 46, 31-425 Kraków, Poland E-mail: rltylek@cyf-kr.edu.pl
Sowa, University of Agriculture in Krakow; al. 29 Listopada 46, 31-425 Kraków, Poland E-mail: janusz.sowa@urk.edu.pl
Rudy, State Forests, Biłgoraj Forest District, ul. Zamojska 96, 23-400 Biłgoraj, Poland E-mail: rudy.piotrek@o2.pl
Gaj-Gielarowiec, State Forests, Barycz Forest District, Barycz 69, 26-200 Końskie, Poland E-mail: dominika.gaj@gmail.com

article id 1159, category Research article

Grzegorz Szewczyk, Janusz Michał Sowa, Włodzimierz Grzebieniowski, Mariusz Kormanek, Dariusz Kulak, Arkadiusz Stańczykiewicz. (2014). Sequencing of harvester work during standard cuttings and in areas with windbreaks. Silva Fennica vol. 48 no. 4 article id 1159. https://doi.org/10.14214/sf.1159

Keywords: time consumption; time series; timber harvesting; harvesters; post-disaster stands

Highlights: In standard cutting stands and thinning areas with windbreaks there occurred three-activity operational cycles. In mature stands with windbreaks the occurrence of stable sequences supplemented with five-activity cycles was noted. Consequently, the operational time in post-disaster thinning stands should be increased by 55% whereas in mature stands it should be 30% longer in comparison with standard stands.

Abstract | Full text in HTML | Full text in PDF | Author Info

The aim of the study was to characterize repetitive cycles of harvester operation. The study was conducted in thinning, mature and post-disaster pine stands. The sequences of the activities characteristic of harvester operation were described as time series. In order to detect the cyclic variable structure of the analysed time series, the methodology of the single spectrum Fourier analysis was applied. In standard stands, post-disaster late-thinning stands and mature stands, the existence of stable operational cycles with the length of three activities was discovered while in post-disaster mature stands additional five-activity operational phases were noted. Described in this way, the lengths of the operational cycles of harvesters working in post-disaster areas were higher by about 55% and 30% respectively, as compared to standard thinning and mature stands.

Szewczyk, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlszewcz@cyf-kr.edu.pl
Sowa, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlsowa@cyf-kr.edu.pl
Grzebieniowski, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: wrzoswj@interia.pl
Kormanek, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest Work Mechanisation, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlkorma@cyf-kr.edu.pl
Kulak, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlkulak@cyf-kr.edu.pl
Stańczykiewicz, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Utilization and Forest Technology, Department of Forest and Wood Utilization, Al. 29-Listopada 46, 31-425 Krakow, Poland E-mail: rlstancz@cyf-kr.edu.pl

Click this link to register to Silva Fennica.

If you are a registered user, log in to save your selected articles for later access.

Contents alert

Your selected articles

Follow @SilvaFennica