Thank you so much, that clears up quite a lot. The formula I need is much cleaner now and I've got a better handle on how to input what I want. I do have one more problem...perhaps you might have some advice on.
I need to write up the correct formula in a programming language that doesn't...
Bill,
Thanks so much, I should have done that to start with. I have attached a notebook showing the original formula I was using(the formula using 0.5 instead of a fraction).
I want Mathematica to solve for Vs so I can write out this new formula as part of programming a...
I used the Reduce function on my on my source equation the output gives three solutions for (Vs) that use the Root[] function.
The first solution gives the correct answer for my purposes when I refine it using a set of actual values in place of the variables.
I don't really understand what...
I am using Mathematica to create a formula to solve for (Vs) in an equation shown at the top of the attached image. Using the assumptions shown, Mathematica outputs three possible solutions, all of which appear to be incorrect when I check them using actual values.
I get this error when...
Thanks Patrick...
I'm going to create a new topic to try to solve the problem with my Mathematica output before continuing because I don't have a formula that works anyway.
Lars
Hurkyl,
Good suggestion! None of the three formulas returned valid results when I plugged values back into them, but the source formula does produce valid results so I am not sure when I am doing wrong. As you can see in the attached jpg I get an error:
"Solve::ratnz: Solve was unable to...
I have attached an image showing the three possible solutions (as determined by Mathematica) when solving for the peak velocity(Vs) in a trapezoidal move where the following are already known: distance(d),total time(t),units of acceleration(Ma),units of deceleration(Ma),initial velocity(Vi)...
OK great, I will proceed accordingly. I have plugged the original equation into the motion control software I'm using, and I immediately see a problem. If AC = DC then I get a division by zero error, because the first item in the equation [ 1/2(ac-dc) ] will always equal zero if...
Thanks! One more question :)
In the original equation you posted there is what I interpret as a Square Root symbol right about in the middle of the equation. I read this as if it extends to the end of the equation from there, based on the placement of parentheses.
In the new results you...
Could I trouble you once more? I would like to see (Vs) solved for using just a portion of the equation, leaving off the deceleration period (the middle portion of the first equation):
d = \frac{Vs^2 - Vi^2}{2AC} + Vs ( t - \frac{Vf - Vs}{DC} - \frac{Vs - Vi}{AC} )
and then using only...
Dear JHamm,
Thank you so much for doing that for me... although I screwed up an would ask you or someone else to plug this equation back into Mathematica for me. I realized when trying to apply the equation you gave that I had included a typo in my original post. There is in fact no "Fs"...
I am trying to program some motion control devices which have trapezoidal motion profiles to define a move. I can define the slewing(peak) velocity, accel/decel rates and distance to travel, the the hardware moves a motor the appropriate distance with the parameters given.
I need to be able...
I am having a lot of trouble factoring the equation once I get it in quadratic form, so I can isolate Vs. Can anyone help? If someone can solve this for Vs or give me more help getting started I'd really appreciate it.
Lars
Thanks for that... I'll give it a try. Am I correct that the x in Vx^2 you mentioned is supposed to be an "s" ? It's been a long time since I've done this kind of math so if I'm not entirely sure I'll get this right... if anyone has some more specific tips I'd love to hear them.
Lars