2015-03-25 20:02 GMT-03:00 Karlsson & Wang <[email protected] >:
> To get higher accuracy you need more accurate measurement, some extra > resolution above the accuracy is also useful. > > For better dynamic perfomance it may make sense to close the inner loop if > the inner loop is faster than the outer loop. If the electic response is > much faster than the mechanical response then there is rather little to > gain from faster control loop. If motor inductance is around 1mH, applied > voltage is 48 volt and current is 10A then U=L*di/dt <=> dt = L*di/U = > 1mH*10A/48V = 0.2ms = 200µs is the time to change motor torque from zero to > maximum which put an upper limit on dynamic response, there is also a > rotational speed dependent back emf reducing available voltage. > > If you do not like the math. Change servo loop peridicity adjust control > loop and see if it make any real difference. > Thanks for the data, and I really like the math, it's just that in cases like these you always want to put the machine to work as accurate as it coul be to make the job and then understand all the theory involved in the process (wich I really like to dig in a lot). Playing with the control loop it has been the best option because with that I achieved a 0.1 mm following error on the linear axis. I'm still managing to tune up the loop for the rotary axis (now I have 1.5 degrees of error more or less) but it's working ok for the job so far. -- *Leonardo Marsaglia*. ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
