Motion Control and Motor Drives

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stepping motor acceleration control

Dear Sir,
About the acceleration method, i still have problem.
please check my attach picture(question01.jpg & question02.jpg & dsolve_linear.vi). I create one VI,try to control every steps and velocity. for example i want the motor from start at 600pps and after 5steps the velocity change to 800pps...
thats means i want to control the motor exact steps (at the this same time to control the exact velocity pps). but I try several method not successful.
please see attach picture "question01.jpg",lower x-y graph is i wanted the motor accelerate curve, after 500steps the motor should be follow some formula accelerated to 14000pps, but the upper graph, which i use acqruire VI to get the acture 7344 card output data. The 73
44 card delay about to 750steps the speed come up to 14000pps. how to prevent this delay, how to control exact motor motion in certain steps.
When I segment the acceleration curve more small the dalay phenomenon more serious, almost out of control.(please see question02.jpg) when i segment this curve into 30segment the output daley up to 1100pps far away from my target. Is thesr any conutermeasure?
If i change to VB or C language can do this?
I have ask this question before (Reference#9525-2YN806), but form my application i cann't us contour, because the contour min. time interval is 10ms, my acceleration time only 40~60ms, that means in the acceleration curve i only can seperated 4~6 segment.
Can you give me any suggest?
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Stone. Unfortunately, the only way to really set position AND velocity is to use a contoured move. So while you can only set 4 to 6 points during your acceleration time, your motors should be at the correct velocity for those points. You can also set the time interval along with the position and velocity between points. This is called a PVT (Position, Velocity and Time) move. This will give you more control over the acceleration during your ramp up time.

Kyle V
Applications Engineer
National Instruments
www.ni.com/ask
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