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Custom Throttle-by-wire on Vanguard engine

Custom Throttle-by-wire on Vanguard engine

(OP)
Hello,
I am working on a project where we are developing a remotely operated vehicle which is powered by a Petrol IC Engine. The engine I am working with is a 23hp Vanguard Engine by Briggs&Stratton. I need to control this engine electrically, using some actuator similar to how it is done in a throttle-by-wire system in a vehicle. With regards to this, I have a few questions:

1. Where should the actuator be connected and how?
2. Should I use a linear actuator or rotary?
3. Is a throttle position sensor required? How to put a throttle position sensor on the engine?

I am attaching a video clip of the throttle lever actuation. Please suggest solutions for this or point to a resource where such a system was implemented.

RE: Custom Throttle-by-wire on Vanguard engine

You should provide a bracket to mount the actuator on that will allow you to apply the control to the same bellcrank the finger is using. Use a standard R/C servo as they're reliable inexpensive and made exactly for that service.

Examples:
Tower Hobby Servos

or better:
Hobby Partz

and:
Pololu - where you can get some servo education with more description and some FAQs

Keith Cress
kcress - http://www.flaminsystems.com

RE: Custom Throttle-by-wire on Vanguard engine

If the engine currently has a cable operated throttle, a linear actuator will replace the throttle cable with little additional modification.

You do not need a throttle position sensor. That is for driving fuel injection systems. You're engine already has that covered.

RE: Custom Throttle-by-wire on Vanguard engine

I was going to say the same thing Itsmoked said. Since you want remote control visit a hobby shop that deals in Radio Controlled cars, boats, airplanes, you will find the remote control and servo your needing.

RE: Custom Throttle-by-wire on Vanguard engine

Typical servo control of model engines is in push-pull configuration so there is no need for the return spring. Since an ordinary radio control system drives the servo to a location proportional to the movement of a control stick, the control stick provides feedback to the operator. It may be advantageous to add a separate throttle position sensor as an error detection mechanism in case the servo or remote control system fails.

One thing to know is that inexpensive servos are signaled with pulse-width modulation. If a servo stops receiving pulses it will tend to remain in position, which means the device being controlled would continue in a possibly unsafe manner. A good addition would be a system that detected that pulses were no longer being given and that system then generating pulses to cause the throttle to close. Such a system is easy to create with a cheap microcontroller, reading pulses from the control system and duplicating them to the servo unless there are no pulses, at which point it generates pulses to send the servo to close the throttle.

RE: Custom Throttle-by-wire on Vanguard engine

You also need to consider that the "finger" in the video is directly operating the throttle plate. This engine is fitted with a governor and the operator normally controls the engine by changing the governor setting, not the throttle plate.

Whether you decide to servo actuate the governor setting or directly actuate the throttle position will depend on what you need the engine to do. For example, - if the engine is driving the wheels through a conventional transmission, you probably need to regulate the engine torque directly - so actuate the throttle.
- if the engine is charging some kind of accumulator (batteries or a hybrid transmission) you may wish to regulate the engine rpm - so actuate the governor.

je suis charlie

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