Never, we created them, we can destroy them.
Hopefully
We already have a body armor that allows the controller to carry massive amounts of weight and run up to 10mph. The government (I think US) has built some of these that can carry up to an extra 200 pounds and feel like 10 pounds.
But it can carry up to (If I recall correctly) 1,000 pounds and then some.
The Japanese have created tons of robots. Include the famous one ASIMO, who still has it's bugs.
But lots of these things can be worked out in time.
Will they work together with man more than they are now?
Most likely.
Will they be able to make decisions for themselves?
I have a theory on how to do this..
But with out my theory. No.
They can only be programmed to do what the creator tells them to do.
Meaning they are LIMITED.
So in general, will robots take over the world?
I say no, they will not.