Control System Project

Control Tutorials for MATLAB and Simulink - PI Control of DC Motor ...

Closed-loop System and Closed-loop Control Systems

That's neat. Yeah, he can improve may be response time or load it on an rc plane perhaps carrying this

An idea is worth something, you know. Why not try to google some patents and do some improvements or modification?

You could build a drone. They have lots of control loops.

thanks for the thoughts.

I just graduated in december and I'm realizing that i know jack sh888t

and I'm trying to fill in some of the gaps hence why i wanted to build something.

I really want to build an inverted pendulum but i figured doing some actual motor control would be the first step.

Yep. Dive right in! No dipping toes!

GA

Response #3 of this posting http://cr4.globalspec.com/thread/110261/Best-Instrumentation-and-Control-Books has a link to a free control systems book you might want to download. It is not an answer to your control systems question but for free the price is right.

Thanks, Bruce. That was pretty comprehensive.

I doubt that it is an accessible solution for you but what you are asking for exists. My company manufactures such a product but it is for 50kW+ . A smaller version (10-25kW) will be available next year.

As others stated, look at the hobbyist stores. They have plenty of nice kits to build your skills. Contact us once you need real power...

Regards

hmmmmmm

Where to begin!

I think what i really wanna figure out how to do is the following.

I would kill to have a real time target machine that i could hook up hardware to and have a model from simulink synthesized to hardware on the target machine and then ran.

This would save me time when i want to change small things in the controller to see the responses. I can just do it in code instead of trying to build real hardware with say op amps or something. Another idea i thought is possibly trying to implement it on an FPGA.

Has anyone done this before? Im sure its possible.

If i wanted to build a digital controller I'm assuming this can be on an FPGA using gates and such? Admittedly i know nothing about the digital control arena. The digital class was not offered when i was in my senior year and will be ordering a good digital book and attempting to teach myself

I guess I'm stuck in general on what i should tackle that would offer the best learning experience per hour of my time. Would type of project would be beneficial and something i could use in a career and not just another you tube video.

Thanks for all the enthusiasm here and if i come up with something interesting ill let you all know! Anymore ideas and comments greatly welcomed

digital . . . . .

The real world that you are trying to master is analog. It is often easiest to measure, analyze and alter (control) it using digital. The digital is the hammer and screwdriver. The analog is the knowledge and wisdom of the carpenter.

It's a shame Bob Pease drive his VW off the side of a mountain after having too many drinks at Jim Williams memorial service. You should still be able to Google "Pease Porrage" and get an ear full (eye full) of what an analog master has to say about people jumping straight to digital.

To a large extent the digital programmer is skilled at taking the requirements of the analog guy and cramming 12 pounds of algorithms into 10 pounds of hardware. Analog is the goal. Digital is typically the best way to get it done. Both are important, but you are not looking for a computer programming job.

I don't know about Simulink. When I was in college the school had 3 computers. Admin had one. One computer lab for beginners had a single computer with about 30 terminals and I think they only ran BASIC. The "advanced" computer lab only accepted decks of punch cards. Let's just say I haven't had any class for a while.

I would assume that it would be cool to somehow plug your test rig into Simulink. I know for sure it would be educational to sit there with calipers, scales and a few other fundamental instruments and figure out how to model your system in Simulink.

One possible starting point would be to consider the erector-set looking rail slide thing that you used to do the F=MA experiments in an early physics lab. That gives you a cheap and easy slider thing. EBay and Amazon probably have these things from some science education shop.

Next use the GlobalSpec web site, Google, Amazon, EBay, etc. and look for linear actuators or any other device where the magnitude of electrical energy into the device controls the amount of linear displacement.

Never under estimate the usefulness of that God-Awful boom box speaker and mega-giga-watt amplifer system that you have in the trunk of your car. I have used them as a very crude shaker table to vibration test devices. I have also tossed the speaker and used my computers sound card through the mega-giga-watt amplifier to provide intentional and repeatable "faulty" power to test devices. There are many useful things you can do with your mega-giga-watt amplifier that are so much better than just driving crazy the peaceful, law-abiding person next to you at the red light. Pull it out of the car and use it in your lab. Your life will be better. Our lives will be better.

There are 3-axis solid state accelerometers on the market at a very cheap price. I believe Analog Devices and several other manufacturers make the chips. I think there are Arduino shields for them. Googling "arduino drone" might provide many useful links.

Computer audio card driving motion, Arduino accelerometer making measurements, everything moving was carefully measured and weighed. All data pushed into Simulink. I'm starting to feel an opportunity to learn coming on.

Being able to accurately and cheaply measure position would be a great next step. At the moment I don't have a good suggestion but someone else might.

When you first do all this the numbers won't all match up correctly. Welcome to the real world. Figure it out and make it right. Take the pebble from his hand grasshopper.

I love digital, but digital is just a tool. Don't get caught feeling good about your tools and neglecting to become a master of them.

By the way, didn't your professor say that analog control systems and electrical control systems are the same thing? Aren't springs = inductors, dashpots = resistors and whatever. A small shopping spree at Digikey or Mouser for a low voltage DC wall wart, a handful of op-amps, caps, resistors and inductors and all you need is access to an oscilloscope. You can under damp, over damp, critically damp, oscillate, filter, etc. You can pretend that the voltage waveform is position and calculate velocity, acceleration, jerk and G-load. It is not quite the same as doing it mechanically but you can gain a huge amount of almost "real world mechanical" experience with $30 worth of parts, a couple of dozen hours and access to an oscilloscope.

You could also use one of the free versions of SPICE and do all this electrical stuff on the screen in front of you for free. A little cross training never hurt anyone. (Linux is often a little more useful than Windows for the DIYer that wants to get his hands dirty on a budget of near zero.)

I feel the need to resume my life, already in progress.

lol wait a second!

you mean you want me to do all the things we are suppose to do in college.....

i have many many resources available to me at the moment but i guess what i really lack at this point is creativity to take my pile of parts ,computers boards, fpga,s, arduinos, raspberry pis etc and make something really cool out of them other then some already done you tube video. Im used to have a professor tell me to "do this" with explicit instructions :)

Im also in the mists of job searching i just need a project to keep myself occupied and continuing learning. My memory is terrible and if I'm not always doing something EE related I'm afraid ill forget half of what i learned!

Thanks again for all the ideas, suggestions and enthusiasm from everyone

p.s i actually prefer analog to digital

My mind works better in S then it does in Z

Perhaps the pebble will remain with the blind guy for a while.

o believe me I'm fast enough to snatch the pebble

If I were you, I would do a research on controls. Find a scheme better than PID and the ones they use in NASA.

A simple system to try....

Get an old loudspeaker from a radio. Cone can be positioned by a DC current. You can step or modulate the current by simple analog means or use ADC/amplifier from whatever. Some vibration tables are like loudspeakers, in essence.

Make a spider or disc (with nut at centre for attachments) and glue it onto the cone centre.

Run a piece of thread or wire (say strand from flexible cable) from the spider to a mirror, with a "hinge" at its other side (could be just a very thin elastic sheet as a hinge). Or you could have a pin in the nut touching mirror.

Shine light beam, e.g. laser plumbline, onto mirror - reflected to remote surface for lots of amplification [the mirror galvanometer principle]. Or maybe onto digital camera... or just put a position sensor against/on the disc (Hall effect? there is a magnetic field).

Current will move spot along wall & wave about with overshoot etc. At audible frequencies, you can hear what happens, use microphone into PC audio capture programme.

This makes a system with inductance in driver, floppy connections, masses and elastic bits that plague a real system.