This is the opposite/complement of my previous question, which concerned measuring the precise position of an object as it is moved/drawn by someone over a short duration. Assuming I use one of @Rocketmagnet's suggested approaches (probably using linear encoders), next:
Suppose I have tracked/recorded the X-Y position data as an object is moved arbitrarily through some pattern across a 2-D plane by someone:
Goal: Now I would like the object to replicate that same recorded movement pattern, i.e., I would like the object to move through those same X-Y positions -- but automated this time.
In other words, I would like the system to carry/displace the object from the recorded (X1, Y1) to (X2, Y2) to (X3, Y3) and so on. Again, completely constrained to a 2D plane/surface, like so:
- I would like fairly controlled/accurate movement of the object, with no greater than 0.5mm error.
- The domain of points for the object to move will extends across a 30cm X 30cm square.
- Exact duration/path between points is NOT critical -- since I will have a fairly well-populated point set (so it will already be pretty close to continuous movement).
The one potential solution I have considered for this (and I think one that is easy to implement) is to use motors placed on the edges but somehow connected to the object. But I am not sure how to connect them in a way that allows 2 degrees of freedom simultaneously, and moreover, I'm not sure how/if it's possible to attain the desired movement accuracy using motors.
So my question is: What are potential methods I can try for this kind of accurately controlled 2-dimensional movement? There are very few physical limitations on my setup as it currently stands, so I am open to toying with (reasonable) implementations of any level of complexity!
One piece of good news is: Since I will have a precise measurement/tracking system (from the previous question), it would be possible to integrate feedback / calibrate during the movement, which I suppose will be essential if I want to assure the 0.5 mm maximum error.
EDIT: In case the exact application is of interest: The system is my attempt at a simplified electronics-art demo of action-replication, i.e., a person's action is recorded and it is then duplicated either after a period, or on a duplicate system nearby. I initially tried working with shape memory alloys (nitinol specifically), but recording a 3-D movement of a multi-point shape was not easy (FAR from it!), hence my simplification to a "single-point" object across a 2-D plane.