# Are there standard angular velocities when it comes to robotic arms?

for manipulators that lift heavy loads, e.g. a car or a cow, what would be the ideal angular velocity?

Are there any standards for arm safe moving speed? (of course I know it depends on the project and use, the question is a yes or no)

Is there any difference when the manipulator works around people ? (since in some cases people can be moving around it, so should it move slower ?)

• waht do you mean by angular velocity ? Do you refer to joint velocity or end-effector velocity ? Jul 27, 2018 at 8:57
• also your second question is rather unclear Jul 27, 2018 at 9:01

First of all there is nothing like an ideal angular velocity. There might be an optimal one based on some cost function you defined, there might be a nominal one related to you operational ranges, there might be a typical one related to the task in general.

Usually the manipulators moving heavy loads are moving rather slowly because of the dynamics effects induced by the load and the manipulator itself. If the load was to me moved faster, it will require more energy and generate way more strains on the manipulator structure. Also typically if you design a manipulator you thing at the level of forces and moments, which implies considering joint torque more than joint velocity.

Lastly concerning the human-robot interactions there are some norms to be followed by industry, ISO 10218 and more recently ISO/TS 15066. Both are rather restrictive in terms of end-effector velocity. Additionally you can look at the work of Pr. Haddadin on human-robot interactions and how to consider different metrics than just end-effector velocity and take into account the shape (and associated trauma) of the end-effector.

• That's exactly what I was looking for! thank you very much ! Jul 27, 2018 at 12:27

Ideally, angular velocity would be provided in radians per second.

Other than suggesting the use of the metric system, there are not pre-specified values for what is best for a robot arm.

These numbers are highly dependent on the current task and robot. Even your term "heavy" is not specific enough- is it heavy for an industrial arm that can lift up cars? Or is it a heavy gallon of milk?

Lastly, not knowing the robot arm geometry also makes this answer impossible. If the robot arm is extremely long then a small angular velocity would result in a very high linear velocity which might not be desirable for your current task. If there are multiple joints, then you probably want each individual joint moving at different velocities, which is again, dependent on the current task.

If you absolutely have to take a random guess at the best angular velocity to use, I would suggest 0 rad/s.

• I love the last sentence. I was working on an answer and it would have been extremely similar. Jul 26, 2018 at 19:33
• thank you for your answer, it didn't help at all but i'll edit the question. Hopefully someone will try to answer it. Jul 26, 2018 at 23:06
• What does the metric system have to do with the answer? Jul 28, 2018 at 5:35