The robotic arm reportedly failed to distinguish between the man and the boxes it was handling.
The incident occurred when the man, a robotics company employee in his 40s, was inspecting the robot.
The robotic arm, confusing the man for a box of vegetables, grabbed him and pushed his body against the conveyer belt, crushing his face and chest, South Korean news agency Yonhap said.
Robots don't get confused. They have a path, and they follow it. This one followed the path when someone was in the way. Why it did is likely human error, either in robot control, programming, or lock out tag out.
It's a safety procedure: if equipment is faulty, you lock the controls with a special device to render it unusable until it is serviced, and a tag accompanies the lock to show when the service call was placed. If locking is impossible, just the tag will suffice.
LOTO or lock out, tag out is a safety practice of physical locking out any and all energy sources attached to a piece of equipment. Gravity, electrical, chemical, potential, pneumatic, hydraulic. You put a lock on it with a tag stating your name, date and typically a reason. You keep that key for that lock so no one else can energize.
Probably just a good old fashioned presence sensor. If the sensor is triggered, there's a "box" there, and the robot does a pre-programmed set of actions. The robot would place the box on the conveyor nicely, but if the man's head and chest stuck out differently than the box does, robot doesn't care. It goes to the programmed position regardless. By the time it encounters enough resistance to trigger the collision detection, the damage has already been done.
Are you sure it didn't have computer vision? This would be a valid statement if it was looking for boxes of vegetables and it confused a human for them