Peter Nachtwey
Member
Good show, Gerry
Gerry is right again! The Rockwell engineer probably did make it clear that their formula was for the time the jerk was postive or negative, not for the whole ramp.
So Gerry, are you up to calculating what you call dS as a function of Vf, Vi and J only? This involves substituting the equation for time you developed into the distance equation. This starts to get messy.
It is best if you use a math package that can do symbollic math. I use Mathcad 11. I am told that Mupad is a similar package that can do symbollic math.
Questions
1. What if the initial acceleration is not zero.
2. How does one know which set of equations to use? There is a simple formula I use to determine whether I use the formula where a constant acceleration is reached or the simpler version you have been working on. I call these two sets of formulas the seven or five segment equations. See the link to Keith's thread above. I explain the seven segments there.
Gerry is right again! The Rockwell engineer probably did make it clear that their formula was for the time the jerk was postive or negative, not for the whole ramp.
So Gerry, are you up to calculating what you call dS as a function of Vf, Vi and J only? This involves substituting the equation for time you developed into the distance equation. This starts to get messy.
It is best if you use a math package that can do symbollic math. I use Mathcad 11. I am told that Mupad is a similar package that can do symbollic math.
Questions
1. What if the initial acceleration is not zero.
2. How does one know which set of equations to use? There is a simple formula I use to determine whether I use the formula where a constant acceleration is reached or the simpler version you have been working on. I call these two sets of formulas the seven or five segment equations. See the link to Keith's thread above. I explain the seven segments there.
I didn't say that. I am just going to let the forum continue this thread at its own pace instead of mine.Dan said:Peter commented it may not be worth his time to post since there are so few responses.