Class-8 Heavy Truck Duty Cycle Project Final Report - Center for ...

Weight [lb]
Weight [lb]
60,000
55,000
50,000
45,000
40,000
35,000
30,000
25,000
Truck Weight Tractor Weight
y = -1229.5x + 48463
R 2 = 0.8668
y = -1043.4x + 28201
R 2 = 0.936
20,000
0.00 0.25 0.50 0.75 1.00 1.25 1.50
Acceleration [m/s 2 ]
Fig. 58. Tractor and Total Truck Weight vs. Acceleration - Medium Load
70,000
65,000
60,000
55,000
50,000
45,000
40,000
35,000
Truck Weight Tractor Weight
y = -2603.1x + 68117
R 2 = 0.9469
y = -1905.3x + 36464
R 2 = 0.9692
30,000
0.00 0.25 0.50 0.75 1.00 1.25 1.50
Acceleration [m/s 2 ]
Fig. 59. Tractor and Total Truck Weight vs. Acceleration - Heavy Load
The methodology to determine truck total weight for trips where the trailer was not instrumented
(94% of the trips) was the same as the one used to test the weight model. That is, using the tractor
AirWeigh readings parameters m, b, and tw (i.e., model M1 parameters) were generated for each time
segment in those trips in which the truck was moving, as explained above. Those parameters were
then used as inputs in the corresponding tractor M2 model to predict the truck total weight. The latter
quantity was then assigned to the corresponding records in the database of collected information.
During the data collection period, the participating trucks were periodically weighted at commercial
vehicle scales and the information from those truck weight scale tickets was entered in a database for
subsequent use in the calibration of the AirWeigh devices. A distribution of the information collected
through these truck weight scale tickets is shown in Fig. 60 below which presents the truck total
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