When the tray moves to a pickup location, it stops above a strip of retro-reflective material, which bounces back nearly all the light it receives. What the machine needs is to accurately know the position of the part and its orientation. Something good for a human being is not necessarily good for a machine. You could talk to it, but speech recognition is not yet reliable enough. You could type commands on a keyboard, but that's slow and sometimes imprecise.
Joysticks work, but give no feedback about forces working against the robot.
Harvey Lipkin believes the answer lies in a force-feedback joystick that pushes back against an operator's directions to give feedback on the environment affecting the robot. The joystick would even stop abruptly if the robot crashed into a wall. That's important because many things you do are force-sensitive. If you can give the human a sense of feel, you can increase system sensitivity. Researchers in the School of Mechanical Engineering are developing improved control schemes which allow robots to learn from their experiences and adapt to changes in their tasks.