Mathias Fr�hlich wrote a long time ago:
> Sent: 08 July 2004 10:38 > To: FlightGear developers discussions > Subject: Re: [Flightgear-devel] status of aircraft carrier > > On Mittwoch, 7. Juli 2004 21:32, Vivian Meazza wrote: > > It would be a shame if we can't model individual wires, then we could > > experience hook-skip whereby the hook can miss all the wires. A chum of > > mine went around 14 times trying to catch a wire in a Gannet aboard HMS > > Hermes. But I think the 'wire-surface' would do quite well. > Hmm, let me explain a bit. > I for myself will be happy to model the relality in detail. > That wire-surface has grown from an experience I have made during the past > half year when I wanted to push changes into JSBSim. For example, I often > proposed a mechanical system which much better models gears. This is not > hard > to do from my point of view. But Jon always told me that this stuff is > tooo > complicated and it is better to keep things as simple as possible. > So that 'wire surface' has really grown from a extrapolation of my > couterpart > in JSBSim to the flightgear community ... > > ... I am happy with individual wires. It is a bit harder since we do only > have > the position of the hook at discrete times. But I have also thought about > that: > Does the surface spaned from the hook in the prevous timestep and the hook > in > this timestep intersect a wire? > If yes we can have a propability where we catch. And if so apply two > forces > from the ends of the wire. > > So the API between the FDM and Flightgear will look something like a > function > taking a geometry of a rectangle and returning a bool which tells if a > wire > is caught and where the two points are where the wire leaves the deck. And > as > usual, how these two points move. > > > It's very difficult to manoeuvre an aircraft onto a cat. You should > > consider modelling the self-aligning rollers and chocks which bodily > shift > > the aircraft into the correct position. This need be no more than a > area > > on the deck on which, if the main wheels are resting on it, a press of a > > key will automatically correctly position the aircraft. > So with a little jump to the right :) > > Sounds sensible! > > > A key press should signify when the pilot is ready for launch, then the > cat > > should fire after a random interval after. > > > > The Jet Blast Deflectors (JBDs) could also be modelled. > Hehe :) > > And a cat officer showing you where to taxi :) > And all these guys with yellow and green and whatever jackets :) > > One by one. But yes ... > > I think I will put several hundred wires onto KSFO's runway to do the > first > tests :) > > > I can provide more details if you are interested. > Yes, whatever you fell that could be useful. > References ... > > Thanks in advance! In the next couple of days or so I will have completed a model of a Seafire IIIc. It has a functioning hook, so I was set to wondering if there was any progress on the arrester wire project??? In the course of the work on Submodels, I realized that it should be possible to re-use some of that code to provide the location of the hook on a near frame-by-frame basis in geodetic terms. Intersection with a 'wire surface' should be possible to calculate. But then we need to apply a suitable force to the fdm. I wonder if a mega-brake would do the trick??? At least as a first try. A couple of pictures are at: http://myweb.tiscali.co.uk/vmeazza/FlightGear/seafire-001.jpg http://myweb.tiscali.co.uk/vmeazza/FlightGear/seafire-002.jpg Regards, Vivian _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
