Small engine speed controller/governor test

This is a Parallax Propeller (P8X32A) based experimental small engine speed controller/governor. In this video I’m doing some basic testing using an old lawn tractor engine. The software implements a proportional-integral-derivative controller (PID controller) to maintain a target RPM even if the load on the engine changes. A PID controller is a generic control loop feedback controller. In this video the knob (potentiometer) on the left controls the target RPM, and the potentiometer on the right controls the proportional Gain (Kp) of the PID controller. At this time, the Integral (Ki), and Derivative (Kd) gain are hard-coded in software and can’t be adjusted externally. The engine throttle is controlled with an old Futaba RC servo.



6 thoughts on “Small engine speed controller/governor test

  1. I have a homemade inverter generator that I made with a PMA (permanent magnet alternator ) and would love to program something that would boost the RPMS of the engine based on dc voltage. Would this be possible ?

  2. This is precisely a circuit I'm interested in.  And, very nice of you to put so much thought into it.  I myself was interested in approaching this in another way;  Developing my own software and programming a pair of microchip 8bit MCU's which are very cheap or going bigger with 16bit.  While flow charting, and pondering several technical questions I noticed many problems with controlling a gas engine with a standard servo.  First on the list was servo destruction.  Any flywheel pickup system that processes in real time would have to average inputs.  Compression, power, exhaust, intake strokes all produce different stroke profiles, and those are changed under different load conditions.  If these things aren't taken into consideration any one shot pickup could produce different responses to the servo, constantly varying it, and therefore overworking and destroying it.  Having no practical experience in application, and you do, how has the system been working for you?  I intend to use a system similar, to provide better governing action, while providing two, to three throttle inputs;  Gas pedal, Standard Throttle, and PTO auxiliary. 

  3. Dear Sir ,
    It's really great control system . I am studying automation subject , and now I have plan to study for Control Simulation of Diesel Engines Electronic Governor by adaptive control . Could you help to share your experience for this solution to me .
    Please send to email thanks so much !

    Regards ,

  4. How do you turning the Kp, Ki ? Why do you think that them siutable for this system?
    I think, You should give PID parameter for each period in order to regulate the stable speed. SC

  5. Great. I was looking at something similar to control an old Generator of mine.  I notice that the mechanical governor is not optimal, and I fancied tinkering! Great post!

  6. Nice work there. PID is amazing!
    Can you control a normal DC motor with PID using encoder as feed back device? Basically build a servo motor for cnc 🙂

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