"Drive by wire" suggestions
"Drive by wire" suggestions
(OP)
Hello All!!
I am currently working on a slow moving (15mph max) off highway vehicle that has a tandem pump directly coupled to the engine. There are two operator control levers connected to the pump via mechanical linkage.
I am trying to eliminate vibration transmitted from the pump/engine to the control levers. One option I am considering is some sort of "drive by wire" configuration (possibly microcontrolled servo or stepper motor?). Can anyone tell me if this can be done economically and possibly list some resources? Everything I have found seems to be for expensive industrial motion control systems.
Some of the initial design parameters:
+/- 21 degrees of rotation (42 degrees total travel) to control each pump input shaft
Actuate the full range (42 degrees) within 1 second
requiring around 10-15 ft-lbf
12 V DC electrical system
Harsh conditions including engine vibration and some moisture
What do you guys think? Is a servo/stepper motor system a good option for this application, or am I missing something. Any info or ideas will be greatly appreciated.
I am currently working on a slow moving (15mph max) off highway vehicle that has a tandem pump directly coupled to the engine. There are two operator control levers connected to the pump via mechanical linkage.
I am trying to eliminate vibration transmitted from the pump/engine to the control levers. One option I am considering is some sort of "drive by wire" configuration (possibly microcontrolled servo or stepper motor?). Can anyone tell me if this can be done economically and possibly list some resources? Everything I have found seems to be for expensive industrial motion control systems.
Some of the initial design parameters:
+/- 21 degrees of rotation (42 degrees total travel) to control each pump input shaft
Actuate the full range (42 degrees) within 1 second
requiring around 10-15 ft-lbf
12 V DC electrical system
Harsh conditions including engine vibration and some moisture
What do you guys think? Is a servo/stepper motor system a good option for this application, or am I missing something. Any info or ideas will be greatly appreciated.





RE: "Drive by wire" suggestions
I think they have a drive by wire throttle.
Mike Halloran
Pembroke Pines, FL, USA
RE: "Drive by wire" suggestions
Problem is "what is cheap enough" for you? And what technical abilities do you have? And are these just move fully here - move fully there, or some sort of turn just barely to this point and change the point according to some system result.
The cheapest solution, if you are just moving to a fixed repeatable position, is to use cable actuators to remove the vibration problem.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: "Drive by wire" suggestions
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If you like it, don't forget to give Clyde38 a star.
respectfully
RE: "Drive by wire" suggestions
Itsmoked, I am actually in the process of assembling a cable actuated system. However, I would eventually like to prototype a model that eliminates the mechanical control levers in favor of a "playstation controller" :)
Movement of the pump input shaft controls the speed and rotational direction of a hydraulic wheel motor. Therefore it is not a "move fully here to fully there" situation.
Correct me if I'm wrong, but I think my basic setup will involve 1) servos to control pump input shafts 2) A main control system to tell servos what to do and monitor sensors 3) input sensors to detect operators desired action, 4) another sensor to detect the machines actual action
My technical abilities are definitely not up to par for what this project will probably turn out to be, so if anyone knows of any servo control kit...let me know :)
Allowable cost for a production run...a few hundred $. For this prototype...under 1000.
RE: "Drive by wire" suggestions
Cost? no idea.
RE: "Drive by wire" suggestions
respectfully
RE: "Drive by wire" suggestions
Well that's pretty a pretty good budget!
Just use a gear drive motor that is reversible.
There are some in automotive land that are cheap and integrated.
Examples:
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There's Jameco too:
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You can use one of the windshield wiper species. You may get the translation aspect for free! Use a short cable to your motor actuator. Run the motor back and forth by reversing the DC leads.
You can go different ways by using a joy stick to dink it to position or an H-bridge for micro control.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: "Drive by wire" suggestions
This would work but it makes me a little nervous. On a vehicle drive, I prefer a fail-safe arrangement. You don't want to have a wire come loose and find that you can't stop.
Respectfully
RE: "Drive by wire" suggestions
Actually just turn the prime mover off, the thing will probably come to a quick stop. (?)
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: "Drive by wire" suggestions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.