The Earthmoving Vehicle Powertrain Simulator at the University of Illinois, Urbana-Champaign

What is an earthmoving vehicle powertrain?
-- a MIMO hydraulic system!

The powertrain of an earthmoving vehicle is similar to that of a passenger vehicle, both of which are comprised the following main components:

The earthmoving vehicle powertrain is different in that it is a fluid power system instead of a mechanical one;it usually has more loads than a passenger vehicle powertrain. So, the earthmoving vehicle powertrain is a Multi-Input-Multi-Output hydraulic system. This figure shows a typical earthmoving powertrain. The variable displacement pump driven by the engine converts mechanical energy into hydraulic power, and drives different loads. The individual load loops are controlled by their own valves.

How to control an earthmoving vehicle powertrain?
-- an experienced operator, or a MIMO coordinated controller!

Without coordination, we can't control a MIMO system even for the simplest task. For example: the powertrain is working at an equilibrium point, and all the different loads are running at a certain speed. Now, a step reference is given to load1. If only one control valve is used without coordinating with other control inputs, of course the load1 speed can be made to track its own reference, but the other load speeds will decrease because their shared flow with load1.

So, we have to aware the MIMO structure of the system and take it as a MIMO control problem instead of speparated component controls. Currently, this MIMO control task is usually performed by an experience operator. And now, we want to build this intelligence into a MIMO controller.

How to test a controller of an earthmoving vehicle powertrain?
-- an Earthmoving Vehicle Powertrain Simulator!

Schematic of The EVPS

click here for an actual photo (161K) of The Earthmoving Vehicle Powertrain Simulator at UIUC
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