Ordered parts on a tray are easy: the robot goes to a fixed coordinate. In a bin the parts overlap, lie at unpredictable angles and shadow each other. A 3D camera or laser scanner captures a point cloud, software estimates the pose of candidate parts, and a grasp planner picks one that is reachable, stable and collision-free, including the approach into a deep steel box.
After each pick the pile shifts, so the whole process repeats. Shiny metal parts are the classic difficulty because they confuse many 3D sensors.
It is a standard step in machine tending: emptying a crate of castings into a CNC machine, or picking mixed items in an e-commerce warehouse, where suction grippers and learned grasp models are common.
