The first torsional mode (otherwise known as "shuffle" mode) of automotive drivelines is excited by engine torque transients and is typically around 2-5 Hz. The effect is particularly severe during step changes from the throttle pedal ("tip-in" or "tip-out"). Shuffle is manifest as a low-frequency longtitudinal acceleration oscillation which, if of sufficient magnitude, leads to driver discomfort. This brief examines the control of this aspect of "driveability" (the error between expected vehicle response and actual vehicle response to an arbitary control input) using feedforward control. The overriding principle to be obtained in this examination is the assessment of electronic throttle control in the context of rapid prototyping. The response surface methodology is adopted to achieve this goal. The potential of the electronic throttle for launch control is analyzed and investigated experimentally, confirming its effectiveness in controlling the first torsional mode.
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