Model Boat Mayhem

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Author Topic: Electronics and Informatics  (Read 1997 times)

Hellmut1956

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Electronics and Informatics
« on: September 19, 2018, 08:53:27 pm »

Due to needs that rose from the way I do my project of the sailboat Carina from scratch presented also in this forum I came up with ideas for electronic based solutions for the project Carina! Initially i started considering the use of electronics when I enjoyed an event during one of our come-together weekends of a German forum. It was the running the naval models during the night!
So after a certain process of developing the idea I came up with the objective to have indirect lightning of the deck and 2 strong LEDs to illuminate the sail of the boat! Of course I wanted to be able to dimm the light using my RC equipment!


Then I run into the idea of implementing a sheet control system with a stepper motor. This goal became a fast increase of complexity and so I run into the limits of my mathematical knowledge from decades ago at the university! Here I found that universities offer the complete courses for free making videos and scripts and reading material required available in the Internet! Starting with it you investigate what is offered in the Internet of so called MOOC. Having the opportunity to study the courses 24/7/365 made evident to me my fascination of topics related to my project of the sailboat Carina.


In this multiple processes of learning and experimenting, a tutorial about stepper motors is another contribution I was able to make also in this forum I rendered my PC inoperable due to attacks from the Internet! This made evident my total lack of knowledge about networking and securing an environment connected to the Internet, a hot topic since a few years for the IoT and IIoT. So about this time I am knowledgeable enough, I hope, to return to the experiments.


My serious health problems do delay my progress very much, but the fascination gives me the will to embrace my project every day. Sad this that by now when I return to a topic after a long time, I need to repeat the learning! I used to read anything once and never forget! Those day are gone!
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Best regards Hellmut

xrad

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Re: Electronics and Informatics
« Reply #1 on: September 21, 2018, 03:33:22 pm »

Hellmut,


There are many easy ways to adapt lighting LED control to sbus or PWM radio control. There are also ways to build a mini wind station to control sails autonomously, and still have RC control.


Check out arduino RC control and LED lighting control with Adafruit arduino.
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Hellmut1956

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Re: Electronics and Informatics
« Reply #2 on: September 21, 2018, 04:41:03 pm »

@xrad: It goes pretty much into details to discuss this topics and I would be very interested to discuss this with you. Thx for the response first!


Many roads get you to Rome!


When I started to deal with the project of controlling the LED the solutions to drive i.e. up to 500 mA to a single LED, the ON Semiconductor device was very attractive! I assume you and me we both know how the intensity of a LED is controlled by PWM. What made the ON Semiconductor device attractive was its ability to drive 10 50 mA. Using a couple of those to reach the 500 or 600 mA for each LED gave me 256 levels of current flow per LED, means on each of this 10 channels. As I am sure you can appreciate, a high performance LED that is fed with 500 mA does generate a lot of heat! So the challenge related to it was to build a lightning device with such an LED in the environment of the deck of a sailboat model. That is why I had to go to boards with aluminium core.


Still so you can safely assume that not every LED in one of the 24 locations does not diffuse the heat similar to the values of heat dissipation of the other LED! Also the heat dissipation capabilities of each lightning device receptacle can also change over time. So the danger for the LED in my environment is to be fed with too much current when dimming to the strongest possible value. So the feedback from the heat sensor directly below each LED will detect when the temperature grows above a threshold I define. The I can individually and dynamically limit the increase of the current fed to the LED so that it does not get hotter then a heat threshold I define.


The second part of your response regarding the sail control system:





To implement a sheet control system that looks like the original in the foto in my case requires to be able to change the length of a sheet of 8.3 meters! This demands a mechanism that controls the length of the sheet in accordance to the angle by which the sail opens in relationship to the enter axis of the boom of the sail. If the sheet gets too loose on the deck it will get stacked to object on the deck and it will get nodes that prevent its control.


So in my system I do use a stepper motor and angular magnetic sensors with 14 bits of resolution. One sensor monitors the angle of the boom and in a table it has associated with each angle a sheet length! So the stepper motor will only provide sheet length required for a specific boom angle! As the the stepper motor has the ability to turn 21 times to get the up to 8.3 meters sheet length I do have more than 52k positions of the stepper motor


I hope my effort to respond respectful and informative to your response! Here the link to my report of building from scratch the sailboat Carina in this forum!
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xrad

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Re: Electronics and Informatics
« Reply #3 on: September 27, 2018, 03:55:56 pm »

Sheet pull length easy to solve with below deck linear rail system which can be altered for length of pull with multiple pulleys (see Pic from my EC12).

http://www.modelboatmayhem.co.uk/forum/index.php?topic=59554.0


As far as super bright  LEDs (with minimal battery requirements) plenty of stuff here (and I have a few of CREE version and they are VERY bright). There are the multicolor versions too. I would not worry too much about voltage /current and heat if using a good LED driver and LED heatsink.  Just need a good heatsink for brightest mode(highest current mode) and these are readily available online and usually already incorporated into the LED.  If you use a cool random fade/brightness and color changing code, you can create some really cool lighting effect on the sail. This is something I was working on 2 years ago, using the main and jib as a type of display screen for light shows and advertisements....

http://www.thecustomsabershop.com/Luxeon-Rebel-C111.aspx

http://www.thecustomsabershop.com/Cree-XP-E2-C136.aspx

http://www.thecustomsabershop.com/LED-Drivers-C109.aspx


https://www.luxeonstar.com/rebel-saber-tri-star-led-assemblies

etc...








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Hellmut1956

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Re: Electronics and Informatics
« Reply #4 on: September 28, 2018, 05:12:22 pm »

Allow me first to thank for your response and answer the statements respectfully:


First to the issue of controlling the length of a sheet. The system that is shown where your links to is very well known to me! The problems with this system if you need and want to change the length by 8.3 meters in a hull that is just 165 cm long cannot be solved by this means:


1. How do you want to implement a change in length of the sheet of 8.3 meters or 27.23 feet?
2. How do you want to prevent blocking of the sheet due to obstacles on deck if the operator wants to have the sail open by 90° and due to luck of wind or wind changing direction of the hull changing direction the sail oscillates back to 0°?
 To have 27.23 feet of sheet loose on the deck of a hull just 5.41 feet length?


In my system an angular magnetic sensor monitors the angle of the boom constantly and makes the stepper motor that works as my winch just have the minimum length of sheet that is required! The sensor reports the angle with a 14 bits precision multiple times per second and the stepper motor corrects the length of the sheet as required with very high precision, any of 52000 positions!


As to the heat dissipation:


An LED that is fed with 500mA current generates so much heat in an LED that is in a very minimal space! Heat practically cannot be dissipated to the air! Here my drawing:





The LED is embedded in the rail and light gets on the deck just through the small yellow colored window drawn in this drawing in yellow color!
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Best regards Hellmut
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