Perception of the Harvester Operator’s Working Environment in Windthrow Stands

Abstract

The aim of the study was to determine the mental workload of a harvester operator when working in late thinning and in windthrown stands of the same type and age, using eye movement patterns as an indicator. Eyeball movement variability was analysed using the eye tracking method. The mean duration of eyesight fixations in windthrown stands was shorter than in the control undamaged stands by about 20% (444 ms and 534 ms, respectively). The mean time of eyesight movements (saccades) in the windthrown stands was shorter than in the control undamaged stands by approx. 15%. The largest differences between the duration of saccades in the windthrown and control stands were observed between the cutting of trees and cutting logs off their root plates: the saccades were longer by about 20% when working in the control stands (49 ms) as compared to the windthrown stands (43 ms). Large differences in the duration of saccades between the windthrown area (42 ms) and the control area (47 ms) were also found when travelling between successive operation sites. In both types of stands, the shortest saccades were observed during processing: 39 ms. Summary durations of saccades observed during the processing of successive trees occurred in sequences showing repeated periods of variable eyeball activity, where longer saccades were followed by shorter ones. Documented more variability of eyesight activities of the harvester operator performing the operations of processing and moving is new standard of eye balls activities for the more taxing work conditions presented by windthrown stands.

Positive and Negative Work Practices of Forest Machine Operators: Interviews and Literature Analysis

“…Sixteen studies were examined in total [4,8,24,27,[31][32][33][34][35][36][37][38][39][40][41][42]. Three out of these studies [24,31,36] were simulator-based studies, and 13 studies were conducted in-field [4,8,27,[32][33][34][35][37][38][39][40][41][42]. Simulator studies assessed more participants, whereas field studies range from 1-6 participants.…”

“…Generally, when reported, the operators that served as participants were experienced and had more than 10 years of experience. Four [4,27,33,36] out of the sixteen studies were assessing forwarder work whereas ten [24,31,32,34,[37][38][39][40][41][42] were concerned with harvester operations, a single study was concerned with a harwarder [35], which is a combined machine of harvester and forwarder. Both thinning and clear-felling operations were the focus of the research.…”

The Effect of Different Road Types on Timber Truck Drivers by Assessing the Load Environment of Drivers by Monitoring Changes in Muscle Tension

“…Alternatively, Babic [42] has used eye-tracking technology on drivers and its relationship with the visual information processing speeds and driver fatigue, e.g., from traffic signs. Additionally, Szewczyk [43] used eye-tracking technology in assessing the psychological load of a harvester operators. The increasing popularity of modern methods that analyze physiological signals is likely due to the accuracy of detecting the participant's condition and the technical innovations.…”

Estimation of Productivity and Costs of Using a Track Mini-Harvester with a Stroke Head for the First Commercial Thinning of a Scots Pine Stand

“…Several authors pointed out that thinning young stands presents several dilemmas, including high operational costs, frequency of invasive trips involving various kinds of field machinery, tree damage [13,14], and mental stress on the harvester operator [15][16][17]. To improve its efficiency, new and more effective methods for harvesting are being sought [18,19].…”