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Design by Modelling

Design by Modelling

Process to define a Sheet Control System for a model Sailboat

Hellmut1956

Aug 11, 2014
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Aug 11, 2014
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Hellmut1956 submitted a new Showcase Item:

Design by Modelling

Hi friends, I want to present an important project that has come up during my project of building from scratch a sailboat model. I use this project as the platform to engage in the most diverse fields and here is one of my babies!

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I started with my sailboat project when it started to get evident that I would not get hired for any new job and so I searched for a project that would not demand much cash and that would help me to have my days filled with activity and by keeping my brain active to succeed to master this difficult condition! I used to build sailplane models as a kid and during my time at the university, but those crash and that implies the need for money. Ships do not crash, worst case sink in a pod at a close lake and so are recoverable. I had very little knowledge about sailboats and so i purchased a plan and start to build from scratch. here a picture that shows how that boat is going to look like some day in the future:



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This second picture shows the sheet implementation as I want to make it happen on my sailboat Model!. In this model the technique used in the original sailboat, the Endeavour, is only fake as the sheet that goes from the deck to the boom at the very rear is what really controls the sail. In my model I need to be able to support 8400 mm of sheet length change so that what the next picture shows is achieved!

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So this kind of "winch" capable to handle a sheet length change of 8400 mm in a sailboat were the hull is just 1650 mm long builds around electronics to establish a control scheme that uses a stepper motor as actuator. I have created a block diagram while trying to enable others to understand what the hack I was talking about!

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Sorry for the text the drawing being in Spanish, but allow me to explain to get the picture!

This sailboat model, I will call it from now on Carina, is radio controlled. So some place at the border of a lake am I with a R/C transmitter. This used to be i.e. a 40 MHz R/C transmitter that poled the status of its controls and send them to a receiver in the model which received this 40 MHz signal and delivered at its 8 ports, called channels, a PWM signal that had a duty cycle of approx. 1 to 2 ms...

Read more about this showcase item here...
 

Hellmut1956

Aug 11, 2014
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Aug 11, 2014
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You are welcome to ask questions, criticize the way I am doing this project and to the objectives of the project. But to filter those out that do not have the background of why I do my project, here my explanation!

I lost my job as a director in one of the largest US telecommunication companies at the time when the Internet boom ended. Now, at least in Germany, at my age then, I became 45 years old, I could not find another hired position and so, as many in my industry, I switched to consulting and I did reactivate my activities as a technical translator and interpreter. To have something to deal with and which would help me to stay up-to-date in the technologies I found of interest, I started a project to build from scratch a model sailboat, as such a project would last for as long as I might wish it to do. As a consequence my way of dealing with what ever I did and do engage with, the way is the objective and not finishing my project. This is the reason why I do follow extensively the topics I meet as part of my project. So please do not come up with arguments like the ones that I should not reinvent the wheel, that I should first finish a project and then start a new one, and so on! I do mention this because I have been confronted with those arguments and those publishing them do often get personal! I have decided to go this way in the way I am doing it!
 

Martaine2005

May 12, 2015
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Why are you trying to reinvent the wheel?
Geez, you should finish one project before starting another!!
Just kidding...
Nice build and a nice project too. Sometimes, one has to have a few projects on the go. Boredom and repetition can be broken up by going from one project to another.
Keep up the good work..

Martin
 

Hellmut1956

Aug 11, 2014
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Aug 11, 2014
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Hi Martin, thanks for responding! I had explained the issue you mention in my thread. I actually do have a lot of tasks, each a project in its own right so that I could switch when I felt better in doing something different. I do:

Work on my Workshop:
I have reports of that project in other forums that do not fit into an electronic forum like this one.

Work on my "Electronics Lab":
As I have decided to add to my tasks an activity that has a lot to do with electronics and with embedded software, design by modelling being the main reason. I do expect to spend at least the time until 2017 and later on it, the effort is to my believes justifiable. In the project log I do explain the issues.

Learning as a beginner to master Linux on the raspberry Pi B+ and 2.

To master FreeRTOS on a LPCXpresso1769, as I will probably use this OS in my sheet control system.

To learn to use Mathematica from Wolfram and to be able to link symbolic data structures in there to data generated in the embedded subsystems. Also the use of Mathematica on the RaspBerry Pi to communicate to Mathematica on the PC to learn how the communication can be done.

Learn the use of SystemModeler, also from Wolfram Software, and its communication via the Firmata Protocol to the supported device "Teensy 3.1". I want this way to study existing ways of communicating external proprietary hardware with Mathematica/systemModeler.

The long term goal of this tasks for preparation I want to learn how to model different parts of my Sheet control system using the language for modelling "Modelica" and to analyze their behavior and so be able to design pretty optimal systems. Now I am sure you know, that data generated from models is only as good as the models. So by using the "solvers" available in Mathematica I want to find equations for use in the Modelica objects which fit as close as possible real data gained from experiments. "Hardware-in-the-Loop", short HiL, and "Software-in-the-Loop", short SiL, are terms that define the means by which I want to accomplish this goals.

As the above demands solid knowledge in electronics, physics and for both and in its own right, mathematics, I have found university courses available for free. It is worth to mention the MIT OpenCourseWare offering of more than 2200 courses taught at MIT and many of them offer the recorded video of lectures and assignments, as well as notes and exercises and the books often for free available legally in the Internet, edx, Coursera, as well as offerings from german universities and of universities in the spanish speaking area of the world. So I have chosen courses were the style of teaching were best fits for me. Sadly serious problems with my health have for some periods made it impossible for me to work on those topics at all, at other times I engaged in mechanical work with my lathe machine and my milling machine, and last but not least on my workshop, which may be one day I will get it to orderly!
 

Martaine2005

May 12, 2015
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I admire a person like you that can have the time and space to keep all projects alive.
Mine seem to be 'organised in a box' for next winter..
One day I will achieve my goals. "What goals" I hear you ask. Nothing in particular, just a really well organized work bench with tools I have but never got out of the box yet!!
Projects I have put to one side, when I understand a little more I can repair them.
Just things like that. Oh, and I have a boat/yacht that was not destroyed while film making of a 007 movie. I will one day remote controll that!!

Martin
 

Hellmut1956

Aug 11, 2014
69
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Aug 11, 2014
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I love to change with you if I could have your health, your job and your age!
 

Hellmut1956

Aug 11, 2014
69
Joined
Aug 11, 2014
Messages
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May be I am excessive! With my intention to "work" with the RaspBerry Pi in the way I have presented it in my project log I felt it worth to refresh/update/new stuff learning quite a few topics:

1. I want to learn Linux and I am using for this purpose a "german bible" for linux as a book from an author called "Kofler" and the edx.org course "LinuxFoundationX: LFS101x.2 Introduction to Linux"

2. I want to learn to use the language "Python" by following the course "MITx: 6.00.1x Introduction to Computer Science and Programming Using Python" and I purchased the Kindle version of the booK
"
Introduction to Computation and Programming Using Python, revised and expanded edition" Which presents how to use Python to resolve tasks programming in Python and keeps introducing the Python language as needed. I like this approach as it combines the use of Python, a language I will them be able to used as an educated user on RaspBerry Pi and get to know its flavours and tools. With flavours I mean that the book goes by using the Python language IDE in version 2.7, which is not completely equivalent to version 3.5. So by having on one monitor screen open both the editor "IDLE" and the command line interface and using version 3.5. When ever the code presented in the book does not execute on 3.5 I go and first verify it works on 2.7 and so I learn how a certain aspect is handled in the current version 3.5. The course from MIT available at edx.org is now speaking about using the "Enthought Canopy Python" environment I have downloaded it in their "Express" version that is made available for free.

3. RaspBerry Pi book from "Kofler" that gives a complete introduction to the RaspBerry Pi, is one of the 2 paths I follow as I am advancing in my studies presented here under points "1" and "2". Their are other good books available for other languages. The purpose is to get a picture of what the RaspBerry Pi and its "eco-system" has available. This is mainly thought as a "reference and introduction" source to its eco-system.

4. Finally I plan to go though the exercises presented in the book "RaspBerry Pi measurements Electronics: hardware and software" from Yury Magda which I have also acquired cheaply for the Kindle. A word of advice: Using the "Kindle software for the PC" allows to read the books in high quality as an ebook on the PC screen. Through this exercises I want to learn how to access external hardware through the GPIOs and special functions like I2C or SPI for example and how to make it possible to have Mathematica from Wolfram link symbolic entities to external data sources as this is supported by Mathematica as an external device being the RaspBerry Pi B+ or 2.

Point "4" should see me prepared to engage into linking Mathematica to my "Sheet Control System". Then and only then it makes sense to purchase a license of "SystemModeler" so that I can combine models written in Modelica modeling language to my proprietary hardware and software system to achieve the models that actually reflect the behavior of the real system elements. This would then allow me to design a good sheet control system based on the optimization iterations done with my Modelica written models, which quality would be the result of the experiments and verifications done by combining "Hardware-in-the-Loop", HiL and "Software-in-the-Loop", SiL.

On the work I am doing with my workshop in general and my electronic lab specifically I have reached the point where I need to organize my pile of stuff in the boxes that can be stores at the places I have build and am building. This is a tedious work as it requires to group stuff to be stored in the proper boxes and write the labels for it. I have also been thinking about writing a database either with the "Access" database of the Office software or to use a database provided by my translation software which could be used for that purpose. Lets see what I will end up with!
 
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