The dynamic range of the fuel injection feedback control loop is probably a factor of 100 or so (pressure and injection time). It's my understanding that the two primary feedback signals are the AFM, which gives the approximate point of operation within the dynamic range, and the O2 sensor, which provides a fine adjust within a very small percentage (1% or so?) at the optimum point within the dynamic range. It's difficult to imagine a "manual closed loop" configuration that would work better in a Vanagon, and easy to imagine that any would work far worse. Note that in the straight and level airplane example the throttle is fixed and the load is fixed, both of which are impractical when driving. Cheers, Tom Neal '87 ...................................................... Some key feedback loop variables to contend with: open loop gain closed loop gain phase margin dynamic range slew rate saturation performance bang-bang or analog output (Vanagon is bang-bang [digital]) time delays sampling rates crossover points ....is this more than we wanted to know about control systems yet? |
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