Impact deceleration for robotics safety
Impact deceleration for robotics safety
(OP)
Hi,
I'm working on figuring out how badly a person gets hurt if hit by the robot. I was planning to determining this using F=ma. Given a force I was hoping to find someway of correlating this with severity of injury to give me a rough idea. I've worked out the top speed of the robot, the weight of robot+payload. The only thing I'm missing is a decelleration value to determine the Force. I tried assuming a decelleration time time of 0.1sec but I'm not sure if this this realistic or not.
Does anyone have any ideas or suggestions about this.
Thanks
I'm working on figuring out how badly a person gets hurt if hit by the robot. I was planning to determining this using F=ma. Given a force I was hoping to find someway of correlating this with severity of injury to give me a rough idea. I've worked out the top speed of the robot, the weight of robot+payload. The only thing I'm missing is a decelleration value to determine the Force. I tried assuming a decelleration time time of 0.1sec but I'm not sure if this this realistic or not.
Does anyone have any ideas or suggestions about this.
Thanks





RE: Impact deceleration for robotics safety
RE: Impact deceleration for robotics safety
I think you need to describe what is going on a bit more fully, is this a collision between a pedestrian and a mobile unit? or a blow from an arm?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Impact deceleration for robotics safety
Thanks for the input thus far.
I'm looking at the safety guarding aspects of a laboratory automation application for a biotech company. The robots are Scara type robot arms with Z-axis capability and are table mounted.
What I am trying to do is get a feel for the injury that being smacked by a robot at max speed with max payload will have on a person. This will provide the appropriate argument for me to show the value added to the barriers/light curtains. I was reading through the R15.06 ANSI standard which is referenced by OSHA, they have a section on choosing the appropriate guarding relating to injury. I know I can put up these big barriers but what my customers are looking for is a safe way to access the unused instruments while the system is in operation by having the instruments on slides or turntables.
The robots used in this application are not the heafty industrial robots used automation type plants they are a bit smaller. It would be nice to have some rough calculations to show that being hit by the robot at max speed and weight would cause permanent damage (the robot seems too puny to cause death).
How is this handled in other industries ? do you automatically assume being hit by a robot causes irreverable injury to a person ? If not how does one go about correlating the impact of a robot with severity of injury ?
Thanks again for the feedback
Cheers
RE: Impact deceleration for robotics safety
You can't be the first one ever to try to do this. Perhaps they could offer you some direction.
RE: Impact deceleration for robotics safety
RE: Impact deceleration for robotics safety
Never design a robot system that allows human access to the workspace while power is on the servos and the machine is in auto operation. ANSI/RIA 15.06 covered this, and that's all the justification you need. Access is permitted only on teach mode, which requires reduced voltage to servos and reduced speed. Guard it, and control access through Schmersal gate switches or similar. I don't like light curtains because folks tend to stick their elbows through them and cause and inadvertent e-stops.
It doesn't matter what the impact force is. Which, BTW, is probably too difficult to try to calculate (KE = 0.5mV^2, coeff of restitution on a human body, area of impact, yadda yadda yadda) and should be done experimentally.
Anything less on an OEM product to a customer is a recipe for a liability lawsuit.
TygerDawg
RE: Impact deceleration for robotics safety
Guard the robots safety like this should not be compromised.
RE: Impact deceleration for robotics safety
Does that put it in perspective?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.