JSBSim Flight Dynamics Model / News: Recent posts

The decision has been made by the team to migrate the development of JSBSim to GitHub. From now on you will find there the bleeding edge source code for JSBSim Flight Dynamics Model. One of the main advantage of GitHub is that it allows continuous integration (i.e. the executables are automatically built and the test suite is automatically executed on each commit to check that nothing has been broken). You can check out this discussion on the JSBSim GitHub project for more details.... read more

There's a Logo discussion ongoing on our brand new Facebook page at www.facebook.com/jsbsim. Look under the Discussions tab.

There's not really a prize, though.

Check out our wiki. This is where we will provide the latest "raw" news on JSBSim (at least the news that is reported more in-depth than the few lines reported here). The wiki can be reached from the JSBSim.org home page. Click on the Wiki link along the menu bar at top. Or, go directly there: http://sourceforge.net/apps/mediawiki/jsbsim/

Improvements to the JSBSim ground reactions code have been contributed and tested with success. Bertrand writes about his work:

"... I have written some code to improve the computation of the friction forces of the landing gears in JSBSim. It is based on the paper from Erin Catto. This paper explains very well how Lagrange multipliers and the projected Gauss Seidel algorithm can be used to determine friction forces. ... I have to admit that the result was beyond my expectations. ... Still the aircraft is behaving well when on ground (even in windy conditions). I have also tested this code on Flight Gear and it worked very well too."... read more

Brian Mills' latest SFunction fo JSBSim has been uploaded to the JSBSim web site and can be downloaded via this link: http://jsbsim.sf.net/JSBSimSFunction.zip.

I have incorporated into the code and submitted to CVS Thomas Kreitler's rotor and helicopter enhancements to JSBSim. This gives JSBSim the ability to model helicopters. This is an initial capability. Comments are solicited.

I've replaced the older P-51D flight model in JSBSim CVS with the extensively researched and meticulously crafted version by Hal Engel. This model has been discussed at length in the FlightGear forums. You can find that forum discussion here: http://www.flightgear.org/forums/viewtopic.php?f=4&t=7494&p=71999&hilit=jsbsim#p71999. The files placed into JSBSim CVS only represent the flight model (Engines, Systems, etc.), but the tar file mentioned in the forum includes the 3D model, flight manuals, etc.

There's a lot being done - at least behind the scenes - on JSBSim these days. We've gotten some additional experienced eyes on the code, which has been very helpful. Some attention is being paid to the equations of motion, tweaking it to more precisely support orbital vehicle modeling. The quaternion and matrix classes have been enhanced a bit to support expanded conversion between the two types.

There is a new tool being developed that sits on top of Digital DATCOM. One of the formats that can be output by this tool that computes aerodynamic characteristics of arbitrary configurations is the JSBSim format. This tool is associated with DATCOM+, which is developed by Bill Galbraith. You can find out more about the new GUI tool at http://www.openae.org.... read more

I have changed the Development Status of JSBSim on the Sourceforge web site to read: Production/Stable.

The rocket engine model is being upgraded. A new rocket engine has been added to the distribution - the space shuttle Solid Rocket Booster (SRB) model. This is the "classic" four segment booster model - not the newer 5 segment SRB model. The model is based on information found on Wikipedia and via other public sources. The documentation is being added to the JSBSim reference manual at this time.

JSBSim v1.0 Release Candidate 2 has been placed in the file download section of the JSBSim web site at www.sf.net/projects/jsbsim.

A JSBSim v1.0 Release Candidate has been posted, replacing the v0.9.13 source code archive that has been on the JSBSim web site for more than 2 years. There are many, many, changes and upgrades to JSBSim for this release. It is important to note that this is a candidate release, and even since this morning, several updates (to the propulsion system) have been submitted to CVS. These will be included in the final v1.0 released sometime in the near future.... read more

A status update on JSBSim was presented to the PC-Based Working Group (PCWG) on Simulation meeting in Las Vegas on Wednesday, April 22, 2009. The purpose of the PCWG is to provide a forum to discuss issues and exchange information pertaining to the use of Personal Computers for both real-time and non-real-time simulation applications. This Working Group focuses on the simulation of Aerospace Vehicles and their related subsystems. In addition, because of the wide versatility of PCs, this Working Group is not be limited to one particular operating system, but rather includes all PC-Based operating systems.

A new mailing list has been added for the growing number of users of JSBSim with Matlab to exchange ideas and discussion:

https://sourceforge.net/mail/?group_id=19399

There is a new JSBSim web site: www.jsbsim.com. The aim of this web site is to act as a point of contact for those who may need more formal or immediate support in the use of JSBSim. See the web site for more details.

A capability has been added to the JSBSim standalone application that permits any number of properties to be settable on the command line using the option syntax:

--property={property_name}={property_value}

The JSBSim web site is getting a facelift. Old pages are being updated, and the manual and web site are being given a common theme. There will be some growing pains so please bear with us.

A Reference Manual for JSBSim is finally coming together. The in-work manual can be downloaded via the Documentation link at the top of the page, or directly at www.jsbsim.org/JSBSimReferenceManual.pdf. The manual will be the authoritative and complete reference for JSBSim, to include a User's Manual, Programmer's Manual, Formulation Manual, Case Studies, JSBSim-ML reference, API reference, etc.

I have added Anders Gidenstam's Lighter-than-air extensions to JSBSim. This includes two new classes, FGBuoyancy, and FGGasCell. The FGBuoyancy class is a collection manager class, like FGPropulsion, FGAerodynamics, FGGroundReactions, and FGFCS. That is, FGBuoyancy manages a list of objects. In this case, the objects being managed are FGGasCell objects, which encapsulate the function of a gas cell.

From Ralf Pfrogner:

I have moved the JSBSim Python Bindings to sourceforge. The downloads come with readme files and instructions on how to build. See:
http://jsbsim-python.sourceforge.net/

I hope this small project is useful for people who want to create small applications based on JSBSim, for example homebrew games, editors for JSBSim configuration files, or simple visualisation tools, when speed is not the main priority, but rapid application development.

An actuator component has been added to the suite of JSBSim flight control components that can be assembled to model a flight control system. The FGActuator class models: rate limiting, position limiting, hysteresis, deadband, and lag. There are also actuator malfunctions that can be set: fail-to-zero, fail-hardover, and fail-stuck.

JSBSim has moved its license from the GPL to the Lesser GPL (LGPL). More information will follow in the upcoming newsletter.

The Winter 2004/5 issue of the JSBSim newsletter, "Back of the Envelope" is online at the JSBSim web site, http://www.jsbsim.org. Click on the newsletter link in the sidebar at left, or select
one of the newsletters at the top of the main page.

The Fall issue of the JSBSim newsletter, "Back of the Envelope" is online at the JSBSim
web site, www.jsbsim.org. Click on the newsletter link in the sidebar at left, or select
one of the newsletters at the top of the main page.

The Fall 2004 issue features contributions by Mathias Frhlich, Bill Galbraith, and Roy
Vegard Ovesen, as well as myself, with articles:

• JSBSim Presented at the 2004 AIAA Modeling and Simulation Conference
• DATCOM+
• The PID Controller
• JSBSim Reference Frames... read more

Jon Berndt presented the paper, "JSBSim: An Open Source Flight Dynamics Model in C++" at the 2004 AIAA Modeling and Simulation Technology Conference in Providence, Rhode Island today (August 16, 2004). The talk was well attended and several good questions were asked.

The interest in open source code is quiet detectable. FlightGear was mentioned in at least one paper.