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A motorized throttle model has been developed in block diagram form (Simulink®). Its primary input is the control signal to the throttle motor's electrical H-driver. The model's primary output is throttle position sensor signal. The model's utility for vehicle and engine simulations is proved with validation data. While a DC motor actuated positioning device is well known, special attention is paid to modeling subtle but significant physical characteristics. Further, the model is structured to overcome numerical simulation issues. The laboratory environment that connects a Powertrain Control Module (PCM) to vehicle powertrain simulation hardware is diagramed. This paper is useful to those modeling this and similar actuators as it points out pitfall avoidance for real time simulation issues. It avoids reliance on difficult-to-measure characteristics that cloud validation validity.

Motorized throttle valves on conventional spark-ignited engines are designed to have a default position such that when unpowered they go to a fixed position which is between closed-in-bore and wide open. This position allows some, albeit limited, vehicle function in the event of a throttle positioning fault. Described here is a new default positioning mechanism attained by rotating the valve past the conventional operating arc (between closed-in-bore and wide open) through wide open to a partially open position. This default throttle position concept eliminates control difficulties and an undesirable failure mode. The advantages and disadvantages are discussed. Further, the required valve geometry is derived.

A time-efficient throttle flow data collection method is described. It uses a sonic nozzle flow bench to measure air flow as a function of throttle angle and pressure in a manner analogous to on-engine dynamometer throttle flow characterization. Opening each sonic nozzle combination, then recording throttle downstream pressure and computed nozzle flow allows data to be taken in a fraction of the time normally needed. Throttle flow modeling considerations are then discussed.