Affiliations: School of Engineering, University of Guelph, Guelph,
ON, Canada | School of Human Kinetics, Laurentian University,
Sudbury, ON, Canada | School of Kinesiology, University of Western Ontario,
London, ON, Canada
Note: [] Corresponding author: Michele L. Oliver, School of Engineering,
University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada. Tel.: +1
519 824 4120 ext 52117; E-mail: moliver@ uoguelph.ca
Abstract: OBJECTIVE: The purpose of this work was to help a steel industry
partner select the most appropriate of three high end heavy equipment seats to
retrofit a number of their heavy mobile machines used in the steel making
process. PARTICIPANTS: The participants included 8 males (22.3 ± 2.0
yrs.) and 8 females (23.5 ± 1.8 yrs.) with no experience operating heavy
mobile equipment. METHODS: Previously recorded 6-DOF chassis acceleration data from a
Pot Hauler (a machine which picks up and transports pots of slag) were used to
extract six, 20 second representative profiles for implementation on a
lab-based heavy machine simulator (6-DOF Parallel Robotics System Corporation
robot). Subjects sat on three heavy equipment seats (BeGe7150, Grammar MSG
95G1721, and a 6801 Isringhausen with the seat pan cushion retrofitted with a
Skydex™ cushion) mounted on the simulator. Each subject completed three
trials for each combination of seat (n=3) and vibration profile (n=6). Chassis
and operator/seat interface vibration were measured by 2, 6-DOF vibration
transducers. Variables included Seat Effective Amplitude Transmissibility
(SEAT) (X,Y,Z,Roll,Pitch,Yaw,6DOF Vector Sum) to determine if the seat was
attenuating or amplifying the vibration, 6-degree of freedom (DOF) vibration
total value weighted predicted comfort (A_{vc}) (according
to ISO 2631-1) and operator reported comfort (ORC). RESULTS: Factorial ANOVAs revealed significant differences (p⩽
0.05) between seats for all SEAT variables but different seats performed better
than others depending on the axis. Significant differences between males and
females were observed for SEAT in X,Y, and Pitch as well as for
A_{vc}. As expected there were significant differences
between vibration profiles for all assessed variables. A number of interaction
effects were observed, the most frequently occurring of which was between seat
and vibration profile. CONCLUSIONS: Based upon the number of seat and vibration profile
interactions, results suggest that a single seat is not suited for all tested
conditions. However, SEAT values for all of the seats tested were extremely low
(e.g., 6-DOF SEAT < 30%) indicating that all of the seats were capable of
providing good vibration attenuation.
Keywords: Whole-body vibration, operator reported comfort, seat selection, ISO 2631-1(1997)
