Potentiometer useage in remote controlled mechanical arm

[Iranon]

I have been working on a project building a mechanical arm and shoulder ending in a manipulator. I would like to control this using a frame mounted to my own arm with a rotary potentiometer at each joint. I'm better at the actual build of the machine than the building of circuits so I need some help on the setup of this. I want the mechanical arm to mimic the actions of my own arm using the pots in the joints and I'm using a flex sensor in a glove to control the end effector. Thanks!

 

[MikeHalloran]

To use a potentiometer, you supply a constant voltage difference across the end terminals. The voltage at wiper terminal lies between the voltages at the ends, in proportion to the physical wiper position.

So then you connect the wiper to the input of a servoamplifier/motor that moves an output shaft (connected to the slave arm) in proportion to the voltage at the input. The motor typically has a pot of its own on the output shaft that tries to minimize the difference between the input voltage and the slave shaft pot voltage by driving the motor.

R/C servos work similarly, except that the control signal is represented by the width of a pulse instead of a voltage.

That's grossly oversimplified. Get some local help.




Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

Look up "string pots". I would think they'd work well for that application.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Iranon]

Thanks, thats about what I needed, just some general pointing in the right direction.