In this section, a virtual system of the proposed simulator, i.e., software based on a numerical model to calculate each thrust force, , as a function of the command of fuel injection, , the angle of throttle, , and the crank angle, , is quickly reviewed (See (Shen 2011) for the details). Note that the crank angle, , is acquired from the hardware, i.e., the piston-crank mechanism. Figure 7 shows a schematic diagram of an engine to be a base of the virtual system.