Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: Michael7S on March 07, 2017, 03:55:08 PM

Title: Actuators too small to simulate human arm?
Post by: Michael7S on March 07, 2017, 03:55:08 PM
To simulate human arm action,  I can build an aluminum test cage and the arm that pivots in the same dimensions as an adult human arm.

Actuator choice will be pivotal ( ;) ) to design of the arms and I could use some pointers on which style/sizes of actuators would be a good starting point.

Some more info: The arm action simulates the plunging of a 12 pound tool, e.g., a soil tamper or post hole digger, for up to 36 inches of vertical travel, at the 'hand'.  Simlar to this video: [youtube]https://www.youtube.com/watch?v=SfFXSGT2qtA  [/youtube]  The cage can remain stationary.   Ultimate goal is to measure the impact force of various designs of hand-operated soil compaction tools.

Thank you for pointers -- either to devices or places where more research can be done.  Most of my searches have included terms like "simulate human arm" and "actuators for axial acceleration" among others, but the results seem to be focused on human performance and medical. 

-Michael
Title: Re: Actuators too small to simulate human arm?
Post by: rastas on April 12, 2017, 05:09:51 AM
hi in my opinion forget trying to reproduce the human movement it looks like a lift then drop movement simple to do with a pneumatic ram
Title: Re: Actuators too small to simulate human arm?
Post by: Michael7S on April 12, 2017, 07:42:16 AM
Thanks Rastas,  I'll look into pneumatic as well.  -Michael
Title: Re: Actuators too small to simulate human arm?
Post by: actuonix on June 20, 2017, 09:24:18 AM
Did you get this sorted out? I agree with the above comment. Pneumatic is probably the way to go
Title: Re: Actuators too small to simulate human arm?
Post by: Michael7S on June 20, 2017, 10:10:24 AM
For now I've used a spring assist for the first 2/3 of the travel.  The last third is pure drop.  This approximates the human propulsion, though a light spring for 100% of the travel might be a touch better.

If I do go to actuated propulsion (and lift), the specs will be much clearer.

Thanks for your help so far.

-Michael

Title: Re: Actuators too small to simulate human arm?
Post by: midhun131 on July 30, 2017, 12:52:11 PM
Pneumatic ram is a good option but then the speeds would be not as per the requirement. Check out either linear actuator/servo. Another method you could consider is a motor and cam assembly.