Help wanted with small factory automation plz

Discussion in 'Embedded Systems and Microcontrollers' started by gilblais, Sep 25, 2012.

  1. gilblais

    Thread Starter New Member

    Sep 24, 2012
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    Hello, Gil Blais here. A newbie with programming skills, more along conventional commercial programming lines. I can handle callbacks, interrupts, etc but have no knowledge how and what specific considerations need attention. C, C++, VB, Java, PHP, JS, HTML5 are all proficiencies.

    I want to automate a furniture factory by starting with a small project that requires 8 holes being drilled into a piece of wood simultaneously via a bank of drills.

    The sequence that I need to perform is:

    1. Operator locks wood in place via a pneumatic lever that releases air to pneumatic valves to produce hold-down pressure on the wood. This is to also be used as a START SEQUENCE signal that a cycle has been initiated. What to use to detect this?
    2. Once a START SEQUENCE situation is detected, we need to send a signal to an electronic unit to start the drills spinning
    3. Send a signal to a pneumatic solenoid that raises the table containing the wood to allow the drills to penetrate halfway through
    4. Send a signal to a pneumatic solenoid that lowers the table containing the wood to the bottom of the drills
    5. Send a signal to a pneumatic solenoid that raises the table containing the wood to allow the drills to penetrate completely through the wood.
    6. Send a signal to a pneumatic solenoid that lowers the table containing the wood to the fully relaxed starting position
    7. Send a signal to an electronic unit to stop the drills from spinning
    8. Operator now unlocks the drilled wood by releasing the pneumatic lockdown lever, ending one processing sequence

    It seems that a simple controller (Arduino R3 ??) is the choice here, but the remaining hardware is where I need some guidance also. Which relays? What power level(s) to use? Which solenoids?

    The system will also need a Panic button to issue a STOP SEQUENCE in case of need.

    An LED indicating red for ‘Active Sequence’ and white for ‘Waiting/Ready’ would be nice. Later I will add an LCD for production info (counts, run time, etc).

    Any help, guidances, references will be gladly accepted. Once completed, I will publish the final working results and possibly a video of an actual sequence running.

    I can be reached at 401-484-0328 if there are items requiring a dialogue.

    Thank You
     
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Nothing. DO NOT DO THIS. It's really dangerous.

    Where are the operator's hands? Are they still on the wood? Are you 1,000% sure they are not in the way of the 8 spinning drills of death.

    There are several ways to insure this. The simplest is providing two buttons well spaced that both must be pressed together to start the machine. They need to be well spaced so it takes both hands to start the machine, and pressed together so one can't be taped down.

    While this is a simple problem and can use just about any controller, until you give me some idea the safety of the operator is the primary mission here I'm not going to discuss any specific details.
     
  3. gilblais

    Thread Starter New Member

    Sep 24, 2012
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    And wood lock is even further away.
    We have an excellent safety record that we are proud of.
    Glad to see you concerned about that.
    Regards, Gil Blais
     
  4. BMorse

    Senior Member

    Sep 26, 2009
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    Have you looked at PLC's? Im sure there are some available that would have all the outputs and inputs you would need to control the valves and drill motors.... and, all you would need to do is get all the off the shelf components and write a program, plus, you would eventually be able to connect multiple machines via network so they can all be monitored from one area, or shut down if needed be.... check here for available automation modules/controllers, etc. >> http://www.automationdirect.com/adc/Home/Home, especially if this is for a factory, might as well get something tried and true, to keep production going.....
     
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  6. John P

    AAC Fanatic!

    Oct 14, 2008
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    Dealing with the questions It seems that a simple controller is the choice here, but the remaining hardware is where I need some guidance also. Which relays? What power level(s) to use? Which solenoids?--

    If I were doing this and not being required to fit in with any existing hardware, I would go with a 24V DC system as that's the most common for industrial automation. You will have to select valves that can deliver the flow rate you need, and then from there add up the current for everything that has to operate simultaneously, and select a power supply with that capacity, with some extra left over for expansion. Interacing with a controller is probably dealt with via the accessory range of that controller's manufacturer, and driving a bunch of 24V solenoid valves is about as basic as you can get.

    If you feel able to write the code, you could just get a computer interface board and run the whole thing right off the computer. But most shops would use a PLC.
     
    strantor likes this.
  7. gilblais

    Thread Starter New Member

    Sep 24, 2012
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    How about using an Arduino R3 in place of a PLC / circuit board? Seems the programming tasks would require more common skills vs the specialized one of a PLC programmer?

    Gil Blais
     
  8. BMorse

    Senior Member

    Sep 26, 2009
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    You can pretty much use anything you want really, but most PLC's are capable of sinking or sourcing more current than an arduino, so trying to set up a 24 (or anything beyond 3.3/5volts) volt system with an arduino or any other microcontroller for that matter would require quite a bit more external components, power supplies, etc..... plus, most PLC's are programmed in ladder logic, probably the easiest to use type of programming that I know of :)
     
    Last edited: Sep 26, 2012
  9. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    An arduino and multichannel relay module would work just fine too.

    Don't forget about levels of safety and stuff like power outage during operation,etc...
     
  10. maxpower097

    Well-Known Member

    Feb 20, 2009
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    Thats what they do with heavy machine guns. Have to pull both triggers for it to fire. He could also use a proximity sensor to make sure no one was in the work area.
     
  11. lawncegary

    New Member

    Sep 27, 2012
    6
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    Im sure there are some available that would have all the outputs and inputs you would need to control the valves and drill motors[​IMG]
     
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