8/9/2014 11:43 PM | |
Posts: 5225 Rating: (1192) |
@Marcjan: You are voicing what I thought but did not say. I was hoping for another approach. You words were civil yet passionate. I hope those words are absorbed. ------------------------------------------------------------------------------------------------------ @Duchuy: I am passionate about people taking up the burdens of engineering - therefore this post. I have a feeling that you know how to negotiate and talk to people. Use this skill. If you are back in "school" ask around on what is available, hidden away in warehouse / storage. Laboratory personal can be a great resource for finding equipment you can use. ..this is my experience talking. More hard but also possible, is to get a sponsor available. Don't just think Siemens; add to your thinking SEW or Omron or .. Instead of giving you all sorts of ideas, I will keep it simple with one idea: Closed loop positioning control of a 3 phase motor driven by a VSD. Onboard to your PLC you have several high speed counters, PWM / pulse train outputs, x2 analog inputs, several multi-purpose digital inputs/outputs, ethernet port and PROCESSING POWER. As standard we have available open loop position control that drives pulse train outputs. These are meant for stepper motor or servo motor amplifiers. As standard these are NOT closed (position) loop when using the motion control algorithms. VSD (inverter) control for AC motors is not covered in this. To create a less accurate but less costly option, you can use the PLC as motion controller for a VSD driven motor. Creating the software is costly but it is a once off cost. Other than the built-in motion control, you could also create a closed position loop system. You can piggyback onto the existing motion controller or develop your own maths or use PI-loop. The sky is the limit to what complexity you can go to.. your concept could even compensate or detect for increase in backlash. okay.. I will stop there to give you time to absorb all of this first. Lastly.. In my part of the world this development would allow us to better control of existing systems without the need to overall everything. This would also use what we have readily available, avoiding costly imports. From there my idea. But my motivation is not important to you.. please find a focus for YOUR work - whatever it may be. Regards. w |
Last edited by: William B. at: 8/10/2014 10:54 PMremove foot from mouth |
|
This contribution was helpful to1 thankful Users |