governor /cruise control

hello
I love arduino projects and I need help with one that I have been thinking about for a while.
I wanted to make a engine governor with arduino but I cant write the code. what I was thinking was this,
if I have a servo motor on the engine controlling the throttle and a 10k pot hooked up to the arduino controlling the servo the I
can rev up and down the engine with the servo. that's all good I can build that, but what I want to do next is add a hall effect sensor to the engine
so I get the rpm of the engine and mix it in with the servo motor, so when I set the engine revs and there is a load on the engine, the hall sensor will pick up that the rpm has gone down and adjust the servo to keep the set rpm.
so it is a electronic gonvernor.
but maybe if you add buttons (remove the 10kpot) then it will be cruise control.
if any one feels like writing me the code you will be my hero.

A small engine already has rotational speed control ("cruise control") that responds to changes in load to maintain an even speed. When you pull on the throttle lever you're not directly changing fuel flow but rather adjusting the tension on the governor for more/less speed; the governor then decides if it needs more or less fuel to hold that speed.

If you're thinking of solving situations where the engine bogs down when under heavy load then you're looking at a problem where the engine is simply incapable of meeting the power demand. You can't change that with any governor -- you need a larger engine.

thanks for the reply.
sorry for the late reply work was flat out.
yes your right, small engines have a governor, but it is hard to keep them at the set rpm. so to make a electronic governor would (in my mind) be better.
I can find the two codes for arduino ( servo motor and a 10k pot, and hall effect senor rpm code) and upload them to the arduino, but what I need help with is mixing them together.
just need someone to help.

@milhobs:

small engines have a governor, but it is hard to keep them at the set rpm. so to make a electronic governor would (in my mind) be better.

Ask yourself, it the electronic governor was really "better" why are they not everywhere? Because there are temperature and electrical (noise) considerations that make this approach more expensive than the traditional air vane governor.

There is merit, I think, in perusing the creation of a device were the intent on an educational basis and if the outcome of the research produced some variable data, but otherwise...

There is some pretty serious math behind process control. Read this and understand it and you will not require anyone to write your code:
http://hrl.harvard.edu/publications/brockett01new.pdf ... anyway, this forum is to assist people who are working on code, have a sample of that code to post, and ask specific questions. No one here is going to write you code for you... it does not work that way.

Ray

mrburnette:
Ask yourself, it the electronic governor was really "better" why are they not everywhere?

They're starting to be. Toyota has drive-by-wire on their cars (you may remember the infamous "unexpected acceleration" issue), other manufacturers are doing the same.

As for the OP, you will probably want to consider "PID control" as a starting point for combining the hall effect sensor with a servo.

wow
that is a lot to read and understand.
I have just work out what to do.
cause it will take to long for me to lean.
and I fully understand why no one will write/help with the code, cause as you said there is a lot involded.
I will just throw the arduino in the bin and go buy something that is on the market.
thanks for the reply
I will ever bother anyone on this site again.

milhobs:
I fully understand why no one will write/help with the code, cause as you said there is a lot involded.
I will just throw the arduino in the bin and go buy something that is on the market.

There is a fair bit of work involved, but it all seems technically feasible. Whether it's good use of your time and money is another matter. To many people, the satisfaction of solving the problem and having a working solution that they built themselves is the big reason for taking on a DIY project. But only you can say whether you actually want to do the project for its own sake, or whether it's worth the time and money to do it yourself, or the cost of paying somebody else to do it for you. If not, then buying an existing product (if there is such a thing) may well be a more realistic option.

I will just throw the arduino in the bin and go buy something that is on the market.
thanks for the reply
I will ever bother anyone on this site again.

Immediate gratification with minimal (if any) work effort on your part. My post was terse because, as you have shown, your interest is just with the outcome, not the trek to the finish. You are a consumer, not a maker, as your response clearly shows.

It takes initiative and time; questions are answered here every day in large numbers. Students are put back on track, code samples are corrected, ideas are bracketed in experience totaling hundreds of years, and references are provided to those who want to learn. A college professor once told me, "... There is nothing that you cannot do with a computer if you have enough time... And money!". Of course, there are some things that should not be done with a computer and there are times when there is not satisfactory time to devise the correct computer solution.

if any one feels like writing me the code you will be my hero.

You need to learn to be your own hero.

Ray