FG1000

From FlightGear wiki
Jump to: navigation, search
FG1000 MFD being displayed (incorrectly!) in a DA-40, and mirrored to a GUI window at 50% scale (02/2018)
Stuart pushed an SVG UI for the FG1000, replacing the PUI version. (01/2018)
FG1000
Started in 07/2017
Description G1000-based MFD emulation
Contributor(s) Stuart, Richard (via Emesary), Michat (UI graphics), www2 (3D artwork) [1]
Status Under active development as of 07/2017
Folders https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Aircraft/Instruments-3d/FG1000/
Changelog https://sourceforge.net/p/flightgear/fgdata/ci/next/log/?path=/Aircraft/Instruments-3d/FG1000


Current Status

06/04/2018:

  • PFD is largely complete. Transponder, NRST, ALT units and alternative units still to implement.
  • MFD is functional, and now includes display and editing of the current flightplan, along with moving map, engine information.
  • MFD and PFD can be displayed as a GUI window under Debug menu or added to an aircraft with the GDU-1045 model as part of a 3D cockpit.

There's still a huge number of pages to write, and the more complex pages around route planning will likely be particularly challenging, but it should be far faster now these blocks are in place. . If anyone is interested in creating a specific page, please also get in touch with Stuart. The various Nearest... and ...Information pages should be quite easy to do based on the pages that have been written already. See the Design Notes for details.

Next steps:

  • Writing the remaining (large) number of pages
  • Styling the pages - making the iconography match Garmin exactly.

Gallery

A Cheat's Guide to Using the FG1000

For those without the time or interest to read the G1000 User Guide, here's a very quick run-down on navigating through the MFD:

General:

  • Click on the buttons, though some are not implemented yet.
  • Use the mouse wheel to scroll the knobs (NAV, HDG, ALT, COM, CRS/BARO, RANGE, FMS). For knobs with both and inner and an outer (NAV, COM, CRS/BARO, FMS), scrolling when pressing the Shift key changes the outer knob.
  • Use the outer FMS knob (shift-mouse wheel on the FMS knob on the bottom right) to navigate through the page groups.
  • Use the inner FMS knob (mouse wheel on the FMS knob on the bottom right) to navigate through the pages within the group. The currently selected page is shown in blue. If you stop moving the cursor, the page will be loaded in 0.5s.
  • Within a page, click on the FMS knob to activate the cursor (CRSR). You you should see some element highlighted on the page, typically flashing. You can navigate around the page using the outer and inner FMS knobs. The Outer FMS knob (shift-mouse wheel) typical moves the cursor between elements. The Inner FMS knob typically changes the selected item.
  • Use the RANGE knob to zoom map views in/out.

Implemented function:

PFD:

  • Artificial horizon, compass rose, altimeter and airspeed indicator
  • HSI that can display NAV1, NAV2, GPS deviation (press CDI)
  • Wind information (press PFD->WIND then select one of the options for display)
  • Bearings to NAV1, NAV2, GPS (press PFD then BRG1/BRG2 to cycle through the options)
  • Inset Map (Press INSET softkey)
  • Active Flight Plan (press FPL when there is an active flightplan to display)
  • DirectTo GPS (press DTO)

MFD:

  • There is a two channel NAV/COM with an active and standby frequency and automatic ID of NAV frequencies at the top of the UI. They all integrate with the standard properties, so should work automatically with most aircraft.
  • If you have a frequency highlighted in any of the pages (e.g. WPT - AIRPORT INFORMATION) press the ENT key to load it into the standby NAV/COM frequency as appropriate.
  • To set up a GPS Direct To route:
    • Press the DTO button (D with an arrow through it on the right side of the panel, below the word "PAN"). This will bring up a Direct To window, allowing you to enter the ID of an airport, Fix etc. to navigate to.
    • You can enter the ID in one of two ways:
      • Scroll the FMS knob backwards to bring up a sub-menu of waypoints categories (FPL, NRST, RECENT, USER, AIRWAY). Use the inner FMS knob to scroll between the different categories, and the outer FMS knob to select a specific item.
      • Scroll the FMS knob forwards to enter an ID manually using the FMS knob. Use the outer FMS knob to move to the next poisition in the ID.
    • Once you've got an ID, press ENT which will load details into the window and highlight the ACTIVATE button.
    • Press ENT once more to load the Direct-to into the GPS and activate it.
  • To view airport information, select the WPT - AIRPORT INFORMATION page. Use the outer FMS knob to move between the AIRPORT, RUNWAYS and FREQUENCY boxes, and the inner FMS to edit the airport ID, scroll through available runways, or highlight a frequency.
  • To edit the current flightplan, press the FPL page, then press the CRSR and enter waypoints for DTO above.

Aircraft Installation

Adding the FG1000 to an aircraft is intended to be fairly straightforward.

Add the GDU to the cockpit

Place one or more of the display (GDU) units in your model. The XML files are in GDU104X directory and are named <model>.<device-number>.xml, e.g.

GDU-1045.1.xml GDU-1045.2.xml GDU-1045.3.xml GDU-1045.4.xml

The <device-number> is referenced later to identify which displays to used for each PFD, MFD etc. You must only used one of each <device-number> value, though you can mix and match the GDU models.

The different GDU models are as follows:

  • GDU-1040 - No autopilot controls
  • GDU-1044B - autopilot controls without VNAV
  • GDU-1054 - autopilot controls with VNAV

Load the Interfaces to provide data

This is used to provide airdata, navdata, NAV/COM settings, engine information to the GDUs. There is a generic interface (GenericInterfaceController) that uses the standard FG route manager, GPS, navigation data and NAV/COM settings, and engine data for a single piston engine.

You need to load it as follows:

var nasal_dir = getprop("/sim/fg-root") ~ "/Aircraft/Instruments-3d/FG1000/Nasal/";
io.load_nasal(nasal_dir ~ 'Interfaces/GenericInterfaceController.nas', "fg1000");

var interfaceController = fg1000.GenericInterfaceController.getOrCreateInstance();
interfaceController.start();

You may want to create your own version depending on what properties you are using for the NAV/COM, and your engine configuration.

Note that you should only start the interface after you've started the FG1000 as they will publish information at start of day that the displays need.

Create an EIS Display

This is the Engine Information System and displays on the left side of the MFD.

There is a generic EIS provided (see FG1000/Nasal/EIS, and FG1000/MFDPages/EIS.svg) that is intended to match a Cessna 172. If you need something different, you should create your own EIS class and SVG file.

Note that you need to pass data to/from the engine using Emesary. See Interfaces/GenericEISPublisher.nas for a reference implementation.

Load and start the FG1000 system

See FG1000/Nasal/FG1000.nas for full details, including how to pass in the EIS. A simple FG1000 using the generic EIS, and displaying PFD on device-number 1 and an MFD on device-number 2 is as follows:

var nasal_dir = getprop("/sim/fg-root") ~ "/Aircraft/Instruments-3d/FG1000/Nasal/";
io.load_nasal(nasal_dir ~ 'FG1000.nas', "fg1000");

# Create the FG1000
var fg1000system = fg1000.FG1000.getOrCreateInstance();

# Create a PFD as device 1, MFD as device 2
fg1000system.addPFD(1);
fg1000system.addMFD(2);

# Display the devices
fg1000system.display(1);
fg1000system.display(2);

#  Display a GUI version of device 1 at 50% scale.
#fg1000system.displayGUI(1, 0.5);

Page Status

This is the current status of the individual pages. Full progress bars indicate that they are functionally complete, though the iconography is not correct.

Page Reference Status Notes
Navigation Map 100}% completed See Layers below
Traffic Map 100}% completed Zoom controls unclear
Storm Scope 0}% completed
Weather Data Link 0}% completed
TAWS-B 0}% completed
Airport Information 100}% completed Needs additional page of AOPA information, which we don't have
Intersection Information 100}% completed
NDB Information 100}% completed
VOR Information 100}% completed
User WPT Information 0}% completed
Trip Planning 0}% completed
Utility 0}% completed
GPS Status 0}% completed
XM Radio 0}% completed
System Status 0}% completed
Active Flight Plan 100}% completed Viewing and editing of the active flight plan implemented. VNAV and the "wide view" not yet implemented
Flight Plan Catalog 0}% completed
Stored Flight Plan 0}% completed
Checklist 100}% completed
Nearest Airports 100}% completed
Nearest Intersections 100}% completed
Nearest NDB 100}% completed
Nearest VOR 100}% completed
Nearest User Waypoints 0}% completed
Nearest Frequencies 0}% completed
Nearest Airspaces 0}% completed

This is the current status of the major functional elements

Area Status Notes
Navigation - FMS 100}% completed
Softkeys 100}% completed
MENU key 0}% completed
NAV/COM 90}% completed Volume controls to be added
GPE Header 0}% completed

Motivation

1rightarrow.png See Canvas_News#Moving_map.2FRNAV_discussion for the main article about this subject.

The enormous variety in current glass flight decks means we really need to think of a new way of defining glass cockpit layouts.[2]


The airspace system is in the process of changing drastically [...] this isn't just a matter of throwing up a canvas showing some GPS waypoints and a magenta line. Modern navigators are astoundingly-complex devices — probably an order of magnitude more lines of code than FlightGear itself — and even their basic flight planning algorithms and databases (e.g. fly-by waypoints vs fly-over waypoints, open vs closed approach procedures, transitions into RNAV approaches, etc.) are far beyond the scope of anything we've tried, and we'd also need an up-to-date database far more complex than the ones we have now. Once you get to the extra features, like FIS-B weather or TIS-B traffic info over ADS-B, or TAWS (terrain alerting), we're probably in way over our heads trying to emulate even the simplest general-aviation IFR GPS.

This may help folks understand what the G1000 is all about: http://static.garmincdn.com/pumac/190-00498-07_0A_Web.pdf Writing a G1000 isn't that hard. Writing a feature complete G1000 is a ton of work. [3]


Depending on how we deal with this challenge, the question is whether that means that the usefulness of FlightGear will also gradually taper off. [4]

Instead of just making one-off tweaks like the consumer sims did, we (as a team) emulated entire systems like the vacuum, pitot-static, and electrical systems, so that failures would be realistic. In the RNAV age, we need to do the same thing; it's just that it's a bigger job. FlightGear will still be great for people who want to practice the mechanical parts of flying (e.g. crosswind wheel landings in a Cub), but will slip further and further behind for people who want to use it for real IFR practice.[5]

Background

1rightarrow.png See Complex Canvas Avionics for the main article about this subject.

Challenges

Performance

Nasal as such is fast, and compared with the cost of rendering the terrain, rendering a canvas display is fast on the GPU (you can test by rendering but not updating a canvas display), and unless you're doing something very inefficient, calculating a display but not writing it to the property tree is fast (you can test this by disabling the write commands). It's the property I/O which you need to structure well, and then canvas will run fast. And of course the complexity of your underlying simulation costs - if you run a thermal model underneath to get real temperature reading, it costs more than inventing the numbers. But that has nothing to do with canvas. [6]


it's a lot of work to code all these displays which someone has to do, but there's no reason to assume it'd be hopeless performance-wise.[7]

we need to be realistic here: The G1000 is a fairly significant piece of computer hardware that we're going to emulate. It's not going to be "free" particularly for those on older hardware that's already struggling. However, hopefully we can offload a chunk of the logic (route management, autopilot/flight director) to the core, and do things like offline generation of terrain maps to minimize the impact.[8]

Route Manager

that's exactly the kind of device James hopes the new code can support. He's read the G1000 pilot's manual, and *thinks* that nearly all the functions can be provided by the current GPS code It would be great if people could look over the current GPS features and indicate any pieces you think might be missing - additional commands, additional search features, extra data, or anything really. [9]

tile servers

Please keep in mind that most tile servers discourage bulk downloads. For the whole planet,oomlevel 8 is approx. 67k files, at zoomlevel 9 you have 265k, level 10 has a little over one million tiles. And one would probably want to go up to level 15 (roughly 1e9 files)[10]

Offline mode

would it be possible to provide an offline tool to pre-fetch a region, like TerraMaster, or terrasync.py? Call me old-fashioned or paranoid, but I don't want FG to go online and do stuff automatically, I prefer downloading what I need manually so that I know what gets onto my harddisk. Also - think of all the people with poor home internet which might have larger bandwidth only in a library elsewhere.[11]

that would certainly be possible - the code retrieving the data is pretty trivial and porting the Nasal code to python or some other script should be straightforward.[12]

Navdata

we need some better data sources, especially with direct routing replacing airways in many areas, and having airspace data would help the map displays, but the current API is specifically designed to support G430, G1000 and similar class devices. Adding RNAV approaches is eminently doable, see the the RNavController base class which the GPS/FMS layer uses to allow new waypoint / route segments to define how they are flown and drive CDIs [13]


Getting the algorithms right, and keeping the data up to date every 7 weeks (we have only a tiny sliver of that data currently), is going to be much more of a challenge. I expect that it's probably an order of magnitude more complicated than our current flight dynamics (etc.), so we'd have to grow our contributor base, and find funding to pay at least Curt (and maybe a couple of others) full time to manage the project. Note that that's what has happened for other complex FOSS projects, like office suites and browsers, which generally end up working through a foundation, rather than our current relaxed circle-of-friends arrangement. The reason it's so much harder now is that the software *is* the product for GPS navigators, FMSs, etc. (unlike with older avionics, where the hardware was the main thing). That means that emulating even a simple unit like the GTN 650 or GNS 430W is almost difficult as building one, so we're trying to keep up with armies of full-time software developers at Garmin, Avidyne, etc.[14]


According to the Route Manager wiki page, we already have support for SID/STAR data provided from Navigraph, which is released on the AIRAC cycle, and costs a pretty small amount (9 EUR for a single download of FMS data, or 90 EUR per year) Given the relatively low cost, I don't think that we as an organiation want to get into trying to digitize data ourselves just to make it open-source or public domain. Particularly given the low cost of a download. We might want to digitize the STAR/SIDs for the default airport with each release so there are some approaches available for those who don't want to purchase the data.[15]

everyone agrees we would like to add airspace data - what we’re missing is a suitable data source with the correct license. Torsten found a raster-based source but for wider use in the sim we really need vector data, so we can render it ourselves directly. [16]

For airspace data we could use https://openflightmaps.org/ . It provides community created navigation data for many countries in (currently only) Europe with a free license.[17]

we definitely want vector data. Stuart is hoping that we might convince the source of the raster data we're using at present to provide it as raw vector data, but we haven't had any luck so far.[18]

Airport Data (US - only )

At least for the US, all required information is available in the form of regularly updated UDFF files:

It would seem relatively straightforward to provide a scripted parser to create the corresponding charts procedurally. As a matter of fact, this could even be done in a background thread or using a separate Python script, i.e. if we wanted to ship pre-created imagery as part of fgdata.

However, if the built-in Canvas system is extended to provide these charts, Phi could also be entirely self-contained by rendering the same airport charts without having to depend on external data sources.


Layers

Following is the list of layers displayed by the G1000 system (see page 153 of the 190-00498-07 Rev. A), and mapping to the equivalent MapStructure Layer. Many of these would also be good to have for other avionics/GUI dialogs, including the NavDisplay framework, which is currently re-implementing this functionality separately, i.e. not yet using MapStructure.

Following is the list of layers displayed by the G1000 system, based on the Garmin G1000 Integrated Flight Deck Pilot's Guide for the Cessna Nav III Garmin Site Wayback machine, page 153, and the mapping to the equivalent MapStructure Layer.

Richard mentioned that if he were to implement approach plates in the EFB he'd probably use raster images provided via http and provide an http service within FG to do this, or to allow the EFB to use any other external web service. Other content for the EFB could be also provided as SVG via http.[19]

Layer MapStructure Layer Status Page Notes
Flight Plan Route Lines RTE Requires styling p.190
Flight Plan Route Waypoints WPT Requires styling p.190
Rivers/Lakes VFRChart p.148 Currently using downloaded raster from web. Perhaps generate similarly to Atlas[20], or could be vector data from scenery. Tom originally suggested to render an ortographic view of the scenery/terrain to the canvas, thus the atlas-based approach should also work using Icecode GL's recent camview element.
Topography Data VFRChart Synthetic p.145 Height-map at chart-resolution. Perhaps generate similarly to Atlas? Tom originally suggested to render an ortographic view of the scenery/terrain to the canvas, thus the atlas-based approach should also work using Icecode GL's recent camview element.
International Borders p.148 Vector data from scenery?
Track Vector p.156 Forward looking display of track. Look-ahead time selectable.
Navigation Range Ring p.159 Straightforward extension of APS.
Fuel Range Ring 159 Straightforward extension of APS.
Terrain Data 364 Should be straightforward, with exception of obstacles. Profile view also required.
Traffic TFC 394,423 Various options, each with different iconography and data displayed.
Airways VFRChart 154 Needs to be replaced with vector data
NEXRAD 282 Heaps of weather data with complex symbology.
XM Lightning Data WXR Change to symbol for lightning? 294 Optional
Airports APT, RWY Require re-style based on size 149, 163
Runway Labels RWY 148 Needs to be added to RWY. Should be straightforward
Restricted OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
MOA (Military) OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
User Waypoints
Latitude/Longitude Grid GRID
NAVAIDs APT, VOR, FIX, NDB APT, requires styling 162
Class B Airspaces/TMA OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
Class C Airspaces/TCA OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
Class D Airspaces OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
Other Airspaces/ADIZ OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
TFRs 310
Obstacles OpenAIP 182 Currently using downloaded rasters. Would be better replaced with vector data, see original plans at Canvas_Maps#Vector_data
Land/Country Text 148 Currently using raster data from web. Replace with POI?
Cities VFRChart 148 Currently using raster data from web. Perhaps generate similarly to Atlas, or could be vector data from scenery. Tom originally suggested to render an ortographic view of the scenery/terrain to the canvas, thus the atlas-based approach should also work using Icecode GL's recent camview element.
Roads VFRChart 148 Currently using raster data from web. Requires vector data from scenery
Railroads VFRChart 148 Currently using raster data from web. Requires vector data from scenery
State/Province Boundaries VFRChart 148 Currently using raster data from web. Requires vector data from scenery
River/Lake Names VFRChart 148 Currently using raster data from web. Replace with POI?
Selected Altitude Intercept Arc 161 Simple extention to APS
SafeTaxi (Optional) RWY, TAXI 493 We don't currently have the data to display taxiway identifier or holding points
ChartView (Optional) 503 Rendering of PDFs. Might be possible to integrate with NaviGraph chart data?
FliteChart (Optional) 521 Rendering of PDFs. Might be possible to integrate with NaviGraph chart data?

Existing work

Avionics / Cockpits

Nasal / Canvas

C++

  • Atlas map creation
  • Synthetic Vision element for rendering viewmgr views to a Canvas
  • Canvas PDF element - for rendering PDF files (think EFB functionality)

Possible Work

Architectural TODO List

This is a short list of architectural improvements I've noted during development that need to be revisited:

  • Use NavMap for MFD Navigation Map, DirectTo, Nearest, Information pages.
  • Separate out the HSI, tapes from the PFD and make them generic MFD UI Elements
  • Improve the performance of the maps, perhaps using a cache for queries, definitely by more aggressive clipping of the SlippyMap layers based on map size.

The layers table shown above mentions a few limitations and ideas, such as:

Nasal/Canvas

C++

  • fix up projection issues, and adopt Gijs' projection handling code for the hard-coded PUI Map, to get rid of the standard Sanson-Flamsteed projection
  • adding a profile view, probably in conjunction with terrain sampling
  • using atlas code to generate heightmaps/topography
  • adding ESRI shapefile support to the Canvas system
  • adding PDF rendering support the Canvas system

Design

The broad structure of the Nasal files in Aircaft/Instruments-3d/FG1000/Nasal is as follows:

  • MFD.nas - top level MFD device, loads the other Nasal files (likely to be moved elsewhere later) and pages.
  • PageGroupControllers.nas - controller for the Page Group display in the bottom right of the MFD, controlled by the FMS knob, and which allows selection between different page groups and individual pages.
  • [PageName]/[PageName].nas - MFD page, inheriting from the MFDPage.nas. Creates any required MapStructure and hierarchy of softkeys.
  • [PageName]/[PageName]Controller.nas - Controller for the MFD page and the MapStructure layers, inheriting from MFDPageController.nas
  • [PageName]/[PageName]Style.nas - Style controls for the MapStructure layers for the given Page.
  • [PageName]/[PageName]Options.nas - Options for the MapStructure layers for the given Page.

Key design notes:

  • Most of the underlying Canvas MapStructure layers are now written (though they require styling, and/or would benefit from replacement with vector data).
  • Emesary IPC framework is used to link between the MFD and underlying simulation state. This should make it easy to run the MFD on a separate FG instance, and provides a good demarkation between the individual aircraft systems and the FG1000 itself.
  • Various underlying UI classes are used to handle highlighting, selection and scrolling of fields. See Canvas MFD Framework for details of the elements now supported.

Resources

Related

Commits

This section is intended to help keep track of related fgdata commits, so that if/when the project should stall, people can more easily look up related changes.


MapStructure related:

References

References
  1. https://forum.flightgear.org/viewtopic.php?f=71&t=32764&start=60#p327229
  2. Robin van Steenbergen  (Oct 2nd, 2007).  Re: [Flightgear-devel] Glass cockpit and external gauges. .
  3. geneb  (Jul 3rd, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  4. David Megginson  (Jul 3rd, 2017).  [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  5. David Megginson  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  6. Thorsten Renk  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  7. Thorsten Renk  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  8. Stuart Buchanan  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  9. James Turner  (Oct 22nd, 2009).  Re: [Flightgear-devel] ZKV500 GPS instrument; (New?) GPS code bug .
  10. Torsten Dreyer  (Sep 29th, 2017).  Re: [Flightgear-devel] Canvas MapLayer for OpenStreetMap, OpenAIP, VFR Sectionals .
  11. Thorsten Renk  (Sep 29th, 2017).  Re: [Flightgear-devel] Canvas MapLayer for OpenStreetMap, OpenAIP, VFR Sectionals .
  12. Stuart Buchanan  (Sep 29th, 2017).  Re: [Flightgear-devel] Canvas MapLayer for OpenStreetMap, OpenAIP, VFR Sectionals .
  13. James Turner  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  14. David Megginson  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  15. Stuart Buchanan  (Jul 4th, 2017).  Re: [Flightgear-devel] RFD: FlightGear and the changing state of air navigation .
  16. James Turner  (Jan 5th, 2018).  Re: [Flightgear-devel] [flightgear/simgear] Nasal regex patch .
  17. TheTom  (Jan 9th, 2018).  Re: Canvas G1000 .
  18. stuart  (Jan 10th, 2018).  Re: Canvas G1000 .
  19. Richard  (Sep 29th, 2015).  Re: .
  20. Torsten  (Mar 17th, 2014).  Re: Atlas still in use ? .