Positioner for a robotic workcell

An apparatus for positioning a feature of a tray, comprising:

• a first source configured to emit a first type of light to illuminate a first region of a surface of the tray,
• a first detector coupled to the source and configured to sense the first type of light reflected from the surface of the tray and provide a first signal comprising information about the sensed first type of light,
• an actuator coupled to the source and to the tray and configured to cause the tray to move relative to the source upon receipt of a command,
• a processor coupled to the actuator and the detector and configured to receive the first signal and send the command, and
• a memory coupled to the processor and comprising instructions that, when executed on the processor, cause the processor to:
• evaluate a magnitude of the first type of sensed light,
• determine the location of the feature relative to a designated location based on the magnitude of the first type of sensed light, and
• cause the actuator to move the tray so as to move the feature toward the designated location.