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Different Roles of Multiple Control Inputs
Of an Earthmoving Vehicle Powertrain

Figure 1 Visualization of an Operating Point

Any operating point of an Multi-Input Multi-Output earthmoving powertrain (See Introduction) can be visualized in a two-dimensional picture. In Fig. 1, the (speed, torque) plane of the engine and the (flow, pressure) plane of the pump are put in the same plot. In this way, we can observe at the same time the operating conditions of the engine in the mechanical domain, and the operating conditions of the pump, valves and loads in the hydraulic domain. (In this example, a simple linear engine model instead of a realistic one is used, which is enough to discuss different input effects.)

For a powertrain with one prime mover, one variable displacement pump and three load units, five control inputs are available to maneuver the system: Engine Throttle, Pump Displacement, and three Valve Inputs. These five inputs play different roles.

Demonstrations for an example powertrain
throttle variation simulation Engine throttle is a Power Generating input: it changes the amount of power generated by the prime mover.	pump variation simulation Pump displacement is a Power Matching input: it changes the transmission ratio in which the mechanical power is converted into hydraulic power.
valve variation simulation Valve commands are Power Distributing inputs: they reallocate the available hydraulic power among different loads.	all inputs variation simulation

Different Roles of Multiple Control Inputs Of an Earthmoving Vehicle Powertrain

Different Roles of Multiple Control Inputs
Of an Earthmoving Vehicle Powertrain