Error in Calculation Time?

[chinahuangyong]

Error in Calculation Time?

[pantor]

This seems to be fine to me. Why should t2 be equal to t4? It would be ambiguous anyway, as the resulting trajectory would be identical (as t3==0). I know that the paper states this, but the Ruckig library has evolved since then 😉

[chinahuangyong]

From the curve, it is true that t3=0, but a2, a3, a4, a5 should also be equal to 0，but here a2 is not equal zero.

[pantor]

Why should a2 be zero? Or, why should t2 == t4?

Ruckig doesn't make any guarantees about the internal data structure of the profiles, and the resulting trajectories are correct and identical. The current data structure has advantages in computational efficiency, so there are some reasons to use a2 != 0.

[chinahuangyong]

like this, if t2 is jerk(-1), and then is t6, this means t3 t4 t5 are all equal 0.

[pantor]

Yes, and what's the problem with t3, t4, t5 being all zero? I currently don't see a bug or issue here.

I think the point is: The trajectories are all identical, and there isn't a unique timing for t1-t7. Ruckig doesn't give any guarantees about the internal timings t1-t7.

[chinahuangyong]

Ruckig doesn't give any guarantees about the internal timings t1-t7, if so, i do not have any problem.

[pantor]

Great, thanks for the clarification!