An apparatus for positioning a workpiece carrier with respect to a
workstation can include an encoder reader located in a fixed position at
a workstation for generating a signal in response to interaction with at
least one encoder strip, a workpiece carrier movable along a path of
travel through the workstation, and having an encoder strip connected
thereto, the encoder strip operably interacting with the encoder reader
located at the workstation, and a non-direct drive or friction drive
engaging the workpiece carrier for moving the carrier along the path of
travel through the workstation, the non-direct drive or friction drive
responsive to the signal from the encoder reader in a closed loop
feedback control system. The encoder reader can be selected from a group
consisting of an optical encoder reader, a magnetic encoder reader, and
any other absolute positioning encoder reader. A closed loop feedback
control system can be provided for receiving the signal from the encoder
reader, and for generating an output signal in response to the signal
from the encoder reader in accordance with a program stored in memory.
The encoder reader can be used for generating a signal corresponding to
at least one of a position identification signal, a workpiece carrier
identification signal, and a workpiece configuration identification
signal.