Work environment of a harvester operator

Abstract

We investigated a harvester operating in Hokkaido to examine the operating environment from the viewpoint of the harvester operator. The work intensity level equaled light physiological loads; the % HRmax of the operator at operating being 54%. The HRmax occurs when the operator is operating the harvester in reverse. The visual field of the operator was analyzed from a photograph taken by a camera with a fish-eye lens. It was considered good results that the main invisible objects in the visual field were gib, head, wheel and instrument for measuring logs, being visibility information at operating, but the operator could not look at the right fore-wheel in the shade of the instrument. Results from an eye-camera showed that the operator looked at the head of harvester, the stand condition, the trees for felling, and the delimbed tree-length log for bucking. Considering the cutting direction of chain saw and the location of instrument for measuring logs, the harvester was operated most efficiently when the operator was looking at the tree for felling and the tree in felling to 10° on the left, and the delimbed tree-length log for bucking and the bucked logs to 10° on the right. From the distributions of time the operator's eye was fixed on different objects, it was found that the instrument for measuring logs required the most concentration. The noise level of the equivalent continuous sound level at operator's ear was 65dB (A) at stopping, 76dB (A) driving, 77-81dB (A) at operating. Those values were under the limit of occupational noise level, that is 85dB (A), in "Occupational Safety and Health Regulation".