Does PID control toolkit worth purchasing?

[bjbdts]

Hi, everyone:

I'm trying to heat up samples in a chamber (The chamber will not be heated up, as the process is very fast). I would like to set a desired  sample tempertuare profile (i.e. how fast the temperature rises, the desired maximum temperture, dwell time, etc.)The temperature of the samples is monitored by an IR temperature sensor. I'm trying to use simple pid control.vi provided by NI to control the temperature of the samples, and get some promising results. But the drawback is it takes a long time to find the appropriate P, I, D values to fit one temperature profile. For different temperatuare profile, different set of P,I,D is required. In addition, P,I,D values will be different for different sample size of same temperature profile. I'm wondering if the PID control toolkit can help me on this, will the PID control toolkit find the appropriate P,I,D values automatically? From what I understand, the PID control toolkit has some auto tuning algorithms to help finding the right P,I,D values. Will it help in my case? Any experiences(good or bad) will help me a lot.

Thanks,

bj

[Brian_Beal]

There are a couple ways to do this.  One is to use the PID toolkit, the other is to get a controller with comms.  I have used the PID toolkit with pretty good results.  The autotuning function works, and usually gets you very close, but if I recall it had some quirks.  You may also benefit from the gain scheduling functions.

[bjbdts]

Thanks, Brian:

I just have some more questions: How long will it take for the autotuning process(seconds or minutes)? For our sample heating, it takes about 20 seconds to heat up small samples, and 1 to 2 minutes to heat up bigger samples. Do you still have to fine tune manually after autotuning process?

bjbdts

[Brian_Beal]

Autotuning time depends on your system.  If it can heat up and cool down quickly, then the autotuning process will be very fast.  Autotuning relies on the algorithm to see a response to a power change.  You may or may not have to fine tune manually.  It depends on how well the autotuning works on your system, and how accurate you need it to be.