What Should You Do When Robot Collide With?

    When programming a robot in manual mode or trying it into automatic mode in production, robot could collide with other robots, machine parts or anything else into the cell. In that case, you may not keep going robot because of the collision effect onto the robot axes. It is hard to continue with just resetting the error and moving robot directly. Robot shock sensors/algorithms/torque controls sense the collision and stops immediately for preventing robot and other stuffs from huge damage. 

Figure 1: Illustration of Collision

         

Quick Information: I create a Reddit topic to understand "How industrial robots understand collision and stop immediately? "

Figure 2: Reddit Most Voted Answers 

    In this post, I would like to mention about how to change the level of the detection of each axes and/or making collision detection valid or invalid for maintaining the robot moveable after robot collision. I prepared some detailed information especially for two robots which are Yaskawa Motoman and ABB brands. You can ask me for more information about other robot brands. 

Friendly Reminder(1): Don't forget to turn on back shock sensing again after your operation. if you don't, robot doesn't stop when crashing so it may cause much bigger damage.

Friendly Reminder(2): Robot collision detection sensors/algorithms are not for safety to protect people. Robots make huge damage until stopping because of the collision detection.

Yaskawa Motoman 4 Axes Robot

Figure 3: Yaskawa 4 Axes Robot Detection Level Menu

ABB Robot Jog and Path Supervision

Figure 4: ABB Robot Jog and Path Supervision

    In addition to that, I would like to remind that another way to use these motion supervision execution settings in production mode. In some applications, robot gripper and the load that carrying by the robot may close or exceed the payload of the robot that change in the distance as you can observe from the Figure 5.

Figure 5: Payload vs Distance(Yaskawa Motoman)

So If your robot gives collision error without any collision unexpectedly, you may opt to turn off or decrease collision sensitivity. If you turn the collision detection off robot doesn't take count into shock sensors or torque control in the movement. You should use this in restricted way, not all the movement. Otherwise robot don't stop when crashing till huge damage occured.

Thanks For Reading...

Okan Okumuş

27.03.2021