Safety analysis of Universal Robots' UR5 robot arm

Описание: Our lab did a series of tests to asses the risks related with Universal Robots' UR5 robot arm. Firstly, we found that the maxmum TCP linear velocity is alsmot 3,000 mm/s. (We did this with Creaform's C-Track optical tracker.) This is way faster than the maximum speed of 255 mm/s imposed on industrial robots operating in manual (teach) mode.

Secondly, we found that if the robot is already constrained against an obstacle, its end-effector cannot exert more than 200 N. There is one major exception, however. If we program the robot to repeatedly cross that obstacle at maximum speed, the UR5 bounces back and exerts nearly 1,500 N at the obstacle.

Next, we didn't dare hit our force plate at maximum speed, but even at 500 mm/s, the force of impact is nearly 1,500 N.

Then, we confirmed that the robot is tolerant to a disturbance force of up to 100 N. It simply deviates from its path. If the force is larger, the robot stops.

Finally, we noticed that it is very easy to forget to specify the correct payload. In such a case, when we press the "Teach" button on the back of the etach pendant, the robot falls down pretty fast. We beleive that the user should be warned before the robot starts to move, e.g. "Please acknowledge that the current payload is 0 kg."

This work was performed by Yannick Boivin, with the help of Yanick Noiseux and Alexandre Filion.