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3220 Views 9 Replies Latest reply: Mar 29, 2013 11:51 PM by Nesikep RSS
damengineer Novice
damengineer
Currently Being Moderated

Mar 10, 2013 9:28 AM

Reservoir sluice gate controller

I am the engineer for a small HOA that owns/manages a 40 acre lake with 6 sluice gates.  The sluice gates were installed to prevent the operation/destruction of the flashboard system originally installed to provide an elevated reservoir level.  I need to find a logic controller that will receive input from the level sensors and raise the gates a set amount than wait a set time before raising or lowering the gates.  I am trying to maintain this reservoir at a level that will not allow more than 6 inches over the gates.   I can install magnetic reed switch level sensors in a dampened level container to detect the reservoir level.  I must keep this system simple.  I was considering a timer switch that would connect when the level sensor closed and operate the gate actuator for 60 seconds than wait 5 monutes then if the level sensor was still closed operate the actuator another 60 seconds than wait 5 minutes.   This system has 2ea 6ft gates with actuators then 4ea 4 ft gates with one actuator controlling 2 gates.  I would want to operate the 6 ft gates first then the 2ea 4 ft gates.  I am trying to maintain a balanced outflow as the gates are installed on each side of the spillway. Therefore needint 2 controllers. There is 120/240 single phase power at each site.   Do I need a logic relay or a logic controller?  Where can I obtain some fast and simple training to program this if needed?   I am a retired consultant and have an above average computer knowledge, but also a below average threshold of frustration!!!  

 

I would apreciate any recommendations.  I have wanted to try PLC's for years but do not know where to start.

 

Thanks in advance!

Tags: microcontroller, sensors, microcontrollers, components
  • MetMan Apprentice
    MetMan
    78 posts since
    Oct 24, 2011
    Currently Being Moderated
    Mar 11, 2013 10:35 AM (in response to damengineer)
    Reservoir sluice gate controller

    What type of budget do you have for this?  I have some ideas how I'd do it but some of the equipment runs in the hundreds of dollars.

  • MikeWeed Novice
    MikeWeed
    49 posts since
    Oct 21, 2011
    Currently Being Moderated
    Mar 11, 2013 12:09 PM (in response to damengineer)
    Reservoir sluice gate controller

    Intriging. I would build this controller using a PIC16F886 microprocessor (about $2 for a LOT of capability) and solid-state relays for the gate actuators. It appears you have 4 actuators, or perhaps 8 if there is a separate circuit for raising or lowering. The relays can be controlled directly by the processor outputs. You have to know the current drawn by the actuators to pick relays that can handle the current. You might consider a solid-state pressure sensor instead of a float switch. This would feed an A/D input on the processor. The PIC16F886 is fairly easy to program (I could do it for you) and has built-in timers. It takes a +5V power supply; A 120VAC to +5VDC would cost around $20. As far as setting up the controller, it could be very simple if all the parameters are programmed into the processor, but then you would need to re-program the processor if you ever wanted to change anything. It would be better to have a digital readout (also controlled by the processor) and several switches and pots so you could change parameters without reprogramming. 

    • damengineer Novice
      damengineer
      5 posts since
      Mar 10, 2013
      Currently Being Moderated
      Mar 11, 2013 12:47 PM (in response to MikeWeed)
      Reservoir sluice gate controller

      I would like to learn to do this for myself as I have had several applications to use this technology.  I would use magnetic float sensors in this application and sloid state relays.  The actuator is a 120v/60cy 1phase 1hp motor with FLA 14A and LRA 73A it takes 213 seconds and 192 turns to raise the gate 48 inches.  After getting some more data, the gates being raised the full 48 inches would not be a bad situation, but I wold still like to use the magnetic float sensors to actuate the gate rather than the mercury switches in the styrofoam balls.  We are controlling a AUMA SA10.1-54A

      Thanks in advance

      • MikeWeed Novice
        MikeWeed
        49 posts since
        Oct 21, 2011
        Currently Being Moderated
        Mar 11, 2013 4:52 PM (in response to damengineer)
        Reservoir sluice gate controller

        After looking over the actuator specs, it appears you need 2 relays per actuator, one for clockwise and another for counterclockwise. Each actuator has a limit switch and a torque switch for each direction, as well as a thermoswitch.

        With this many I/O, a PIC16F887 processor should be used (same as '886, but more I/O). To program these yourself, you need something like the PicKit3 (Digikey PG164130-ND, $44.95) with a 6 pin header (0.1" pitch) and a socket on a Vectorbord. If you do much programming, a ZIF socket is a good investment. The PicKit3 is run by Microchip's MPLAB, a free download. I write programs in Assembler (the One True Language) for these processors. It takes a while to learn Microchip's assembler language, but I would be happy to help you get started. The source code file (written in assembler) is processed by utilities in MPLAB to generate a Hex file, and PicKit3 writes the Hex file to the processor using its ICSP (in circuit serial programming) interface.

        • damengineer Novice
          damengineer
          5 posts since
          Mar 10, 2013
          Currently Being Moderated
          Mar 11, 2013 9:07 PM (in response to MikeWeed)
          Reservoir sluice gate controller

          THANK YOU!  I have tried to figure out where and how to get started with these for several years.   I could find no one here around OKC that I could get a straight answer from...  Would you mind listing what I should get to get started.  I will have to get the system working  pretty soon but I can get the parts going and then install before the spring rains....I should also mention that there are 3 gates at each side of this spillway.  The Auma actuators are the latest installation and one is on each side.  There are also 2 gates connected by a common shaft to one actuator on each side.  These gates are raised if the reservoir level continues to rise about 6 inches above the first sensor.    A little background:  The spillway flashboards I mentioned in the original post are held up by 2in. round iron pins stuck in concrete.  These pins are tested randomly to assure failure consistency and are calculated to bend with 1.5 ft of water flowing over the flashboards.  The center section of this 200+ wide boars system has 1.5in bars  in the center 50 ft to cause an intiial failure.   Problem is this causes a domino effect from the tension on the board system.  To make a long story short, this system costs between $20K and $50K to replace depending on what can be salvaged and labor.  Not to mention the loss of 4 ft of the reservoir and the over 70 boats grounded...  Still, with all this at stake, the HOA is in rough shape due to having to spend $140K last month to repair the riprap.  I have several clients that could use this technology in addition to some of my own projects here on the farm.  You can maybe get an idea of the work I do at www.thatdamengineer.com

          Thanks again for the info, if you do not mind giving me a list of what to get to get started I will get it ASAP

          Damengineer

          • MikeWeed Novice
            MikeWeed
            49 posts since
            Oct 21, 2011
            Currently Being Moderated
            Mar 12, 2013 2:47 PM (in response to damengineer)
            Reservoir sluice gate controller

            Hi Cecil,

            You will need a DIP ZIF socket for your programming fixture like Digikey 3M4006-ND (not the one you ordered).

            You will also need a 6 pin header (Digikey A26550-ND) to connect the PicKit3 to this socket. The fixture can be built on a vectorbord (Digikey V2011-ND). Cut off a small part with a bandsaw or shear and use the larger piece for the controller prototype. Small gauge solid wire like Digikey V1087-ND is good for wiring. Tools needed will include Picture 021.jpgwire strippers, small diagonal cutters, needle nose pliers, soldering iron, solder, etc.

            After it is programmed in the fixture, the processor will be placed in a socket (Digikey A94140-ND) on the prototype board. You will need 5VDC for the processor which you can get from the 120 VAC source using Digikey 102-2386-ND. I assume the limit switches in the actuators and the float switch will be at some distance from the controller, so it is highly recommended that the processor inputs be isolated from the cruel world using optoisolators. As far as I can make out, you intend to run 4 actuators, each having 5 limit switches. Optoisolators like Digikey H11L2M-ND should work for this, and there is a price break at 25 pieces. All chips in the design phase should be put on sockets; good sockets for the optoisolators are Digikey AE10021-ND. Finally, (and this is the major parts cost), the AC to the actuators need to be switched, preferably using solid-state relays like Digikey CC1080-ND. These are good for 25A which shold give you a good safety margin in case of actuator problems. I think you need 8 relays for 4 actuators, and there is a price break at 10 (a couple of spares wouldn't hurt).

            I have made a preliminary framework for the processor program and am attaching it. Also attached is a drawing of how the processor should be wired to the other parts.

            Attachments:
  • Nesikep Novice
    Nesikep
    2 posts since
    Mar 29, 2013
    Currently Being Moderated
    Mar 29, 2013 11:51 PM (in response to damengineer)
    Reservoir sluice gate controller

    I was wondering what sort of equipment you already have?  is there already some servo device of sorts to raise and lower the gates and is it capable of an incremental control?... Assuming you have this already...

     

    Why not go with something like a pressure sensor? I'm thinking something similar to a MAP sensor on an engine, which would be able to give you an analog signal of the water level... If you have an old laptop (or desktop, as long as it has serial and parallel ports), Using the serial port as an input (it could take inputs from both the water level sensor, and a second sensor on the gate mechanism), and you can use the parallel port as a digital output very easily even with VisualBasic.  I'm currently working on a PID program in VB with a PWM output.

     

    Rereading your first post, I think the best simplest that could work for you (Maybe even with an analog sensor) would be something like an Allen Bradley Powerflex invertor/motor controller, and using a 3phase motor to raise and lower the gates... I think you might be able to do it with the invertor alone with the "Step logic" feature which gives you 8 "logic" steps and has a couple timers in it...  The best part of them is they run on single phase 220V, and 3ph motors are easy to come by used (I often get nearly new 2hp motors for $40).  I have one I use to run my lathe, and a "stirring machine" which slowly ramps up to speed in one direction for a preset time, then slows down, stops, and reverses, and is all done without a PLC through the invertor... I think you'd need two of these... Depending on the size of the motors you need (1HP sounds like it would be plenty with a reduction drive), I think the cost of a unit  is between $4-800 according to

    http://www.plchardware.com/Products/81/5398649/5398651/default.aspx depending on the size, which would leave a fair bit of money left over for sensors, etc, but you wouldn't need relays anymore.  In fact, you'd have money left over for a PLC if you needed it, and invertor controlled motors are SO much nicer to work with that relay controlled motors... If they raise or lower too fast, you can just set a long acceleration ramp time on a low frequency and don't have to change gearing

     

    Hope that gives you some more food for thought

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