Bridge Command Forum

General Category => General Discussion => Topic started by: elir71 on May 22, 2018, 12:00:25 PM

Title: Enhancements (Was: Compiling under Linux Fedora 28)
Post by: elir71 on May 22, 2018, 12:00:25 PM
I'm new to using git so please bear with me

I have (tried to) send some ammendments via a fork and pull request

I have not compiled under windows,  I have compiled under linux however I have not uploaded the executables

The ammendment I have made for your consideration and incorporation are as follows :-

1. Softcode the roll period

 as it is primarly a function of the stability condition of the vessel so in the models/ownship.boat.ini there is a new parameter of


denoting a roll period of 6 seconds.  this parameter can be altered to suit the vessel,   Something like a car carrier would typicall be 12 sec.  future plans for this is to softcode pitch period too and to try and model a propensity for synchronous and parametric rolling which is basically a rapid increase in the amplitude of the roll due to resonance between the natural roll period of the vessel and the wave encouter period

2. Place a very basic rate of turn indicator on the GUI, also moving a few exisiting controls to accommodate it
 todo on this would be to softcode the range is measures,  A rib would turn far faster than a vlcc. 

3. Alter the user's interaction with the steering to more accurately reflect follow up mode on a ship.  The rudder can only be moved at a limited speed, but the steering wheel can be moved instantaneously.  To that end the user now controls the "wheel" and the rudder follows it at the rate defined in boat.ini of Ownship the units being degrees per second


the above example would define the rudder can be moved by the steering gear through a maximum of 6 degrees per second

typical values for a rib woudl be 90, almost instentaneous
for a 100m general cargo ship 2 degrees per second
big old vlcc 1 degree per second 

I hope this meets with your approval
Title: Re: Enhancements (Was: Compiling under Linux Fedora 28)
Post by: forum_admin on May 24, 2018, 03:50:38 PM
Thanks, I've seen your commits on github, and what you describe sounds very useful. I will have a good look how best to integrate these.
Title: Re: Enhancements (Was: Compiling under Linux Fedora 28)
Post by: forum_admin on July 30, 2018, 07:50:04 AM
Thanks very much, I've merged these changes. I've now combined the wheel and rudder indicator into one, so you control the rudder, and the wheel position is shown with a secondary indicator.
Title: Re: Enhancements (Was: Compiling under Linux Fedora 28)
Post by: elir71 on August 08, 2018, 05:21:46 PM
Great, thank you for accepting the suggestion

I've been working on an AIS aspect to this.  I've got as far as writing a Message type 1 module and am part of the way through Message type 5 (name, destination , etc etc).  I've not started ammending the existing code to push this data to these modules (and thence to OpenCPN over network), though I think that would be the easy bit.  The aim being a realistic display on openCPN of other vessels so you can get AIS derived CPA TCPA etc (still a debated subject in practice)

I'm off to sea for about 6 months shortly, so I shall have to put it on hold for that time