Hi Bart,
I couldn’t agree with you more regarding the vibration and marine environment. I remember asking a commissioning engineer what were the plastic struts on each of the control systems boards. He said they were to stop the boards flexing due to vibration from the ships engines; he also added that they were coated in a anti-fungal varnish for when the ships were in tropical climes - we were using them in a power station! With the wire wrapping, we had to ensure that the last three turns included the insulated part of the wire to act as stress relief on the bare wire.
One thing with my controller is that I can unplug it and put in my pocket for safe keeping.
I’m not actually using wire-wrap for this project. The system I use is “Vero-wire”, which has a pink insulating coating that becomes the flux when soldered, i.e. no need to strip the insulation before soldering; the wire’s diameter is only 0.2mm. The board is a gold-plated copper strip matrix type; I just poke the wire through the hole, bend it and solder and then test for continuity.
The controller was a development of a previous one, which was nearly three times the size. The current controller took three days for the layout design and three days to construct. The software development took two years to perfect, including learning the best method to control the monotube!
The software is written in assembler and the system runs in real time, since it has to respond to real-world events.
The main elements of the board are: two thermocouple amps, a display controller, the process controller, a pulse shaper, three RPM chips, a timer and an LED bank.
I have considered using something like the Allen-Bradley Programmable Controllers, but they were far too large to fit in a model boat – might be an idea for a full-size boat though. Another problem was sourcing a low RPM module to measure the pump strokes per minute (SPM) for the range 0.5 SPM to 200SPM and would also update every stroke.
Thanks for your interest Bart.
Keep on steaming!
Ian
Perfect control of monotube boilers in our lifetimes!
- barts
- Full Steam Ahead
- Posts: 1088
- Joined: Wed Nov 18, 2009 6:08 am
- Boat Name: Otter, Rainbow
- Location: Lopez Island, WA and sometimes Menlo Park, CA
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Re: Perfect control of monotube boilers in our lifetimes!
Thanks for filling in some of the details. I've written various kinds of software for digital control include multi-axis robots; I always enjoy writing software that has a immediate physical effect, and yes, control algorithms are always a challenge - esp. when one is programming on a limited environment like this.
Nice work - and I look forward to its application in a larger boat!
- Bart
Nice work - and I look forward to its application in a larger boat!
- Bart
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Bart Smaalders http://smaalders.net/barts Lopez Island, WA
Bart Smaalders http://smaalders.net/barts Lopez Island, WA
Re: Perfect control of monotube boilers in our lifetimes!
Hi,
It has been a long time since adding to this thread and the flash boiler, engine and control system have been installed in a new model, see YouTube:
https://www.youtube.com/watch?v=2HV4s9MjfaQ
In addition, a voice control (via a radio mic) and solid-state compass system have been developed and installed. The system has nearly fifty voice commands ranging from rudder trim to navigation instructions for example "GO WEST" and "FIGURE OF EIGHT" - it even responds to "MORE STEAM"!
The on-board MP3 player is also linked to the voice control system and the command "SAILING" starts the track "Sailing" by Rod Stewart. The intention is to build an old fashioned disk player to be fitted on the Edwardian Steam Launch.
So, there you have it - a voice controlled flash boiler!
Ian
It has been a long time since adding to this thread and the flash boiler, engine and control system have been installed in a new model, see YouTube:
https://www.youtube.com/watch?v=2HV4s9MjfaQ
In addition, a voice control (via a radio mic) and solid-state compass system have been developed and installed. The system has nearly fifty voice commands ranging from rudder trim to navigation instructions for example "GO WEST" and "FIGURE OF EIGHT" - it even responds to "MORE STEAM"!
The on-board MP3 player is also linked to the voice control system and the command "SAILING" starts the track "Sailing" by Rod Stewart. The intention is to build an old fashioned disk player to be fitted on the Edwardian Steam Launch.
So, there you have it - a voice controlled flash boiler!
Ian