How can I control the position of a pneumatic piston?
The only way I know about is using a magnetic reed switch (magnetic sensor) with a matching piston and use some type of control algorithm, like PID for instance, to keep the piston where the sensor is.
The problem with that is that it gives you only limited control of the position, it just adds another "state" (open, closed, sensor position) and not full control. for example I want it to be 43% once and 70% the other time, but without using a sensor for each position because I would like all the "options" to be available (I mean that the percentages aren't pre-defined)
This is an example of the pistons I use:
This is a good example of what I want: http://www.youtube.com/watch?v=A8LZ15uiuXU