Robotics deep dive: THREE FINGERS OR FIVE
The robot-hand world is arguing about finger count, and a startup went and checked the data.
Tacta
@TactaSystems put tactile gloves on expert factory workers in Japan, China, Vietnam, Mexico and Taiwan, and watched what the best hands actually do.
The finding: high-value precision work comes down to three fingers.
A thumb, an index and a middle finger do the picking, placing, inserting and threading.
The ring and the little finger mostly go along for the ride.
Look at your own hand holding a pen or a small part: two of your fingers are just there for support.
The robot even improves on the human here.
A robot finger does not tire and does not overheat, so it can hold a 2 kg part for days without a break.
So why does almost everyone still build five?
The honest answer is the training data, not the task.
Five fingers match the human hand you are learning from, which closes the embodiment gap between the demonstration and the robot.
That congruency is why the five-finger camp is prominent.
Tacta's answer is to not be dogmatic about it.
Three fingers for the job, because it is simpler, cheaper and more robust.
Five if a customer wants the human match.
The design is modular, so you can even add a sixth.
The lesson here: let the data pick the finger count.