| 摘要 |
<p>An engine speed control unit for a gas turbine engine, e.g. an aircraft jet engine, is operative to adjust the level of fuel flow and incorporates in the control loop means for smoothing the rate of acceleration or deceleration to a newly demanded speed to avoid overshooting or undershooting the new speed. This is particularly effective when decelerating to a new low speed by avoiding engine speed undershoot and thus the subsequent re-acceleration which can cause a surge. The deceleration curve is smoothed controlling the rate of deceleration by substituting a false demand level NHd for the newly demanded speed PLd, and by progressively reducing the substituted level in an iterative control process so that actual engine speed NH is substantially assymptotic to the demanded speed after roughly four iterations. <IMAGE></p> |
