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Haul Truck Specifications
To access these functions:
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Activate the Schedule ribbon and select Setup. Select any haul truck item on the left.
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In the Update Schedule dialog, enable the Haul Trucks option and click the browse button.
The Specifications control group is used to define the haul truck mass, drive wheel load distribution and traction parameters. These form part of the settings on the General Settings panel for each truck
Field Details
Vehicle Weight (tonnes): enter a values for the Empty state.
Load Distribution on Wheels (%): enter values for both Empty and Loaded states.
Coefficient of Traction: enter a value.
Compute Accelerations: if unchecked, a static speed will be used for the distance travelled for EFH, if enabled, the schedule will be constructed based on an acceleration formula.
How acceleration is calculated
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The maximum force without slipping is calculated using the load distribution, weight, gradient and traction coefficient:
maximum force without slipping = cos ( atan ( gradient / 100 ) ) * weight * traction coefficient * load distribution / 100 -
The rimpull force is calculated as follows:
If using the rimpull and retardation model, rimpull force is looked up on the chart using the current speed.
If using the linear model, rimpull force = gross weight * sin ( atan ( effective gradient / 100 ) ) -
The force of gravity is calculated:
force of gravity = sin ( atan ( gradient / 100 ) ) * weight -
The accelerating force is calculated:
accelerating force = ( smallest of rimpull force and maximum force without slipping ) – force of gravity -
The acceleration rate is calculated:
acceleration rate = accelerating force * 9.81 / weight -
The acceleration time is calculated:
acceleration time = ( max speed – current speed ) / acceleration rate -
The acceleration distance is calculated:
acceleration distance = acceleration rate * acceleration time * acceleration time / 2
