OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Analysis of variance (ANOVA) was performed to identify the process parameters that were statistically
significant. With the ANOVA analyses, the optimal combination of the process parameters was predicted.
Worker Age, Work Time Duration and Workplace Temperature were selected for investigating the effect on HR
during MMH task. Vertical Height, lifting Frequency, Box Size and Weight of Lifting Load were kept constant
during the entire experimentation. The design parameters as well as their chosen levels considered for the
Taguchi experiment are listed in Table 2.
Table 2: Parameters with their levels
Parameters
Levels Age of Worker
(Years)
Work Time Duration
(Minutes)
Workplace Temperature
(Degree Centigrade)
Level 1 20 9 20
Level 2 30 13 27
Level 3 40 17 34
Fixed Parameters
Vertical Height 90 cm, Lifting Frequency 4 lifts/minute, Box size 40*40*20 cm and
weight of lifting load 15 Kg
The basic objective of the study was to evaluate the effect of parameters associated with a lifting task to
minimize the risk of injuries caused during MMH task. The desired responses from such a study would be Heart
Rate during the lifting/lowering task. Based on the literature review and the pilot experiment results Workers
Age, Working Time duration, and Workplace Temperature were identified for this study. Three male workers of
age 20, 30 and 40 years had participated in this study. All three selected male workers were not having any type
of disease or health problems. The experiments were conducted at each trial conditions as given in Table 3. For
each trial, experiments were replicated (three times). For each experiment free style lifting technique was used.
Pebbles were used as the lifting material. The responses of heart rate during all nine trails each repeated three
times are given in Table 3 along with its S/N ratio considering as smaller-the-better.
Table 3: Experimental Design and Responses of each Trial
Trials Parameters Responses of Heart Rate
Age (Years)
Work Time
Duration (Minutes)
Workplace
temperature
(Degree Centigrade)
R1 R2 R3
S/N Ratio
1 20 9 20 88.03 90.15 87.4 -38.94
2 20 13 27 95.6 91.22 93.23 -39.40
3 20 17 34 110.22 108.38 112.27 -40.85
4 30 9 27 115.31 113.16 116.31 -41.21
5 30 13 34 135.48 128.78 131.5 -42.41
6 30 17 20 118.12 114.14 110.36 -41.15
7 40 9 34 132.01 135.26 127.8 -42.39
8 40 13 20 122.78 125.11 120.65 -41.79
9 40 17 27 133.28 135.21 128.65 -42.44
TOTAL 1050.83 1041.41 1028.17 -370.59
Mean HR T = 115.57
692