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Mechanism analysis: Domain boundaries &

HelterSkelter

New member
User defined functions?



I'm busy specifying the motion of a servo motor. The motion curve is
composed of piecewise analytical curves. The boundaries of each
piecewise section are determined by the models geometry and are hence
not constant.



I've run into two ugly problems in trying to get my motion into the servo motor:

1) The time domains for segments of a user defined function are
normally specified in the form :0.27 <= t <= 0.4. I really need
to spec the boundaries with parameters rather than numerical values.
This doesnt seem to work for me. Can this actually be done?



2) Altenatively I could put an analytical description of the whole
range in one time domain. But here again I'm snookered by the lack of a
max() function in the cut down built-in function list of the user
function window. Basically if my function goes negative I want the
returned value to be a zero rather than a negative value. The positive
function evaluations would be used as return values.



I really seem to have been check mated here by ProE's petty
limitations. Can someone advise me on how to overcome these problems?#



smiley18.gif
 
I've run into two ugly problems in trying to get my motion into the servo motor:


1) The time domains for segments of a user defined function are
normally specified in the form :0.27 <= t <= 0.4. I really need
to spec the boundaries with parameters rather than numerical values.
This doesnt seem to work for me. Can this actually be done?




I don't think you can put parameter in the limits for the function.<br style="color: rgb(0, 0, 255);">





2) Altenatively I could put an analytical description of the whole
range in one time domain. But here again I'm snookered by the lack of a
max() function in the cut down built-in function list of the user
function window. Basically if my function goes negative I want the
returned value to be a zero rather than a negative value. The positive
function evaluations would be used as return values.

<br style="color: rgb(0, 0, 255);">
I think you can use a computed measure with a "if else end" logic stament. For example If F(x)<=0, then 0 else F(x). <br style="color: rgb(0, 0, 255);">
<br style="color: rgb(0, 0, 255);">
Without realy looking at your problem with more detail I would not be able to specify other workarounds.



Luis
 

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