Re: [Flightgear-devel] Helicopter: First Impressions
On Fri, 23 Jun 2006 14:42:34 -0700, Maik Justus wrote: Is there any other helicopter (3D-model) in preparation? Just saying this publicly lest someone else start on it (or if someone else wants my Blender file thus far), I've got a good bit of the high struts version of a Bell 205 under way. It's probably way too low poly count, and I'm not going to get back to it for at least a month, but if someone else wants to either pick it up or go with something else (Perhaps an A-Star for those of us who like flying around glaciers) that's cool. If I remember right I had some body fairing to do, and then the difficult stuff (instrument panel) started. Dan Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Hello Melchior, thank you very much. It helps me much to find the correct input for the tail rotor. Is it possible to switch it to a air-speed-drift-indicator? Maik Melchior FRANZ schrieb: * Maik Justus -- Friday 23 June 2006 23:42: @Melchior: is it possible to add an instrument, which shows the lateral movement of the helicopter or the direction of the translation? Done. There's a GSDI (Ground Speed Drift Indicator) on the right side, under the VSI. The implementation is rather simple, and loosely modeled after a photo. Unfortunately, it is almost impossible to get photos. Seems to be top-secret stuff ... I had another implementation first with direction needle, but thought the current one was better. (?) m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
* Maik Justus -- Sunday 25 June 2006 23:49: Is it possible to switch it to a air-speed-drift-indicator? Not the C++ instrument, because it's a GSDI and that's not how these work. But you can open $FG_ROOT/Aircraft/bo105/Instruments/gsdi/gsdi.xml and replace the two properties instrumentation/gsdi/drift-[uv]-kt with velocities/[uv]Body-fps. m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Hello Melchior, Very good. Thank you. Maik Melchior FRANZ schrieb: * Maik Justus -- Sunday 25 June 2006 23:49: Is it possible to switch it to a air-speed-drift-indicator? Not the C++ instrument, because it's a GSDI and that's not how these work. But you can open $FG_ROOT/Aircraft/bo105/Instruments/gsdi/gsdi.xml and replace the two properties instrumentation/gsdi/drift-[uv]-kt with velocities/[uv]Body-fps. m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
On Saturday 24 June 2006 00:29, Maik Justus wrote: - ground effect Look into Mathias' ground cache. This should make it quite easy to get the necessary altitudes quickly. I will have a look on this. Is this used in yasim? Yes it is. There is an api in FGInterface which can be used to get agl values in a small environment from the aircraft. There is just a small cache containing the scenery triangles a few meters around the aircraft. Feel free to ask if there are some problems. Greetings Mathias -- Mathias Fröhlich, email: [EMAIL PROTECTED] Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Josh Babcock schrieb: Martin Spott wrote: Josh Babcock wrote: I like your todo list. I would just suggest one more thing. If you look at a helo from behind, the rotor disk will be canted slightly to one side in straight and level flight. The side force offsets the side force of the tail rotor to prevent sideslip. In FG, instead of the rotor disk being tilted to the left a few degrees, the whole aircraft is. This might very well be a phenomenon that's unique to helicopters which are based on this hingeless rotor concept, aircraft and rotor mostly move as one entity. They vary significantly from the typical Bell rotor style: http://www.christoph31.de/cgi-bin/MasterFrameReunion.cgi?http%3A//www.christoph31.de/foto/details.php%3Fimage_id%3D590%26 Martin. Yeah, this behavior may be appropriate for the bo105, I have a picture of an EC-135 with a semi-rigid rotor in a 1" hover that has that has that same tilt, though it might have just been wiggling as it lifted off. Most of the rotors out there, however, are still fully articulated. There are even a significant number of teetering rotors still flying. Just about every Jet Ranger has one. It is definitely not right for them. As far as I can tell, YASim treats all rotors this way. Josh I think the simulation is correct at this point. But there is a second source for the tilting of the fuselage. The tail-rotor itself gives some moment to the fuselage, depending on the height where the tail-rotor is connected. (This effect is simulated as well.) I've never calculated the strength of this effect, but I expect it to be not negligible for the Jet Ranger. A UH1 I expect to hover more ore less parallel to the ground (depending on the cg). If we trust the simulation (I do), we can check this by using the bell206-simulation and modify the height of the tail-rotor to be the same as the main-rotor. In a RL teetering system for instance, the rotor does not transmit any pitch/roll torque to the mast at all until the hinge reaches its limits, it just tugs it fore and back and side to side. This is only correct for rotor heads with the hinge exactly in the center of the head (like Jet Ranger, UH1). If the hinge is not in the center (e. g. CH53), the rotor transmit torque to the mast. The rotor head of the Bo can transmit more torque to the mast, than the mast is designed for. Therefor the Bo has an instrument, which shows the moment on the mast. I have some documentation on the bo105 here. There is a comparison of the bo105 and the bell206. If you put the stick to one side the bell206 needs 1.7s for reaching 63% of the final rotational speed. The sa341 (gazelle) needs 1.2s and the bo105 needs 0.2s. Therefore the bell206 reacts very delayed to any input on the cyclic and the bo reacts instantly. Maik Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Maik Justus wrote: OK, you are clearly way ahead of me on this. Everything you say makes perfect sense, so I retract my original request. The welcome back still stands though! Josh Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
* Maik Justus -- Friday 23 June 2006 23:42: @Melchior: is it possible to add an instrument, which shows the lateral movement of the helicopter or the direction of the translation? Done. There's a GSDI (Ground Speed Drift Indicator) on the right side, under the VSI. The implementation is rather simple, and loosely modeled after a photo. Unfortunately, it is almost impossible to get photos. Seems to be top-secret stuff ... I had another implementation first with direction needle, but thought the current one was better. (?) m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Hello all, after a long period of absence on business and family I now want to fix some of the missings in the helicopter simulation. But first I have to say thank you to all of you, because of the great development of flightgear in the last three years. And a very big thank you to Melchior for the great Bo105. The first thing I started to work is the co-work with yasim. I was not able to set up yasim correctly. Therefore the fuselage and the stabs were not producing any aerodynamic forces. (Therefore it was necessary, that the rotor itself produces extremely large drag to avoid to high maximum speed of the helicopter. This was the cause for the unrealistic low descent rate.) Now I found how to setup yasim correctly. This is the base for calculation of downwash effects on stabs and fuselage. With this change the bo105 feels significantly different (and I hope more realistic; but all my knowledge is based on model helicopters and theoretical consideration.) Furthermore I have included the air-pressure to the calculations. The bo now does not any longer climb to unlimited heights. Now I want to add/fix - ground effect - more realistic calculation on power-consumption. Autorotation and co-operation with the yasim engines is my aim (Is there any rotation-speed-controller in yasim?) - translational lift - comments to the source - downwash effects on fuselage and stabs - vortex state With these points the helicopter simulation should obtain much more realism. Is there any other helicopter (3D-model) in preparation? @Melchior: is it possible to add an instrument, which shows the lateral movement of the helicopter or the direction of the translation? With this it is much easier to find the correct setting for the pedals. On real helicopters I saw such a instrument realized in two different ways: one was measuring the diefference of the air-pressure on the right and the left side of the heli, but I do not remember how the instrument self looked like. The other was a simple piece of string on the outside of the cockpit. (There is a small bug in the movement of the blades. Due to gyro effects the rotor reacts (about) 90° delayed. If you put the stick forward, the left blade will decrease incidence). Best regards, Maik Maik Justus schrieb: Hi Maik Justus wrote: The helicopter simulation is not finished yet. I will describe later, which functions/ effects are totally missing or simplified. Here it is: Missing: -Downwash -Effect on stabs -Effect on rotor itself -Effect on ground (ground effect) -Engine (The needed power is calculated, but very simplified (i.e. a autorotation is not possible now) , but the rotor now accelerates in 5 sec and hold than the revolution for every circumstances) -Fuel consumption -Garbage collection to the source -Comments in the source Unrealistic: -Translational lift -Teetering (I am not sure, which effect the teetering has. If I try to calculate it, I get some discrepancies) -Lift and drag from the Rotor blades is very simplified. To use realistic values of a realistic airfoil should be not very complicate (and then the needed power would be realistic and autorotation should be possible) -The rotor is simulated at only 4 points. To use many points along the rotor blades is much better. And maybe much more, which I forgot to mention here ;-) The bo105.xml contain only more or less realistic rotors. The fuselage and the stabs are still missing. (the same for bell206like.xml, ch47like.xml and as350like.xml). (I am not sure if the stabs are working correct without the solver. I tried to use fixed values if you specify no wing and hstab, but maybe there is a bug. In the ch47like.xml the vstab seems to have no effect at all) All the best, Maik P.S.: I would be very thankful if someone would correct my english in the README.yasim ___ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
* Melchior FRANZ -- Saturday 24 June 2006 00:12: Yes, there is an R22, and Josh works on a CH53. Both not in CVS. )The R22 probably won't ever.) The R22 is available here: http://www.geocities.com/flightgearproject/ Don't know if it still works with current cvs, though. m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Hi Melchior, Melchior FRANZ schrieb: * Maik Justus -- Friday 23 June 2006 23:42: Hello all, ... - ground effect Look into Mathias' ground cache. This should make it quite easy to get the necessary altitudes quickly. I will have a look on this. Is this used in yasim? With these points the helicopter simulation should obtain much more realism. Is there any other helicopter (3D-model) in preparation? Yes, there is an R22, and Josh works on a CH53. Both not in CVS. )The R22 probably won't ever.) good (more helicopters) and bad (not in cvs) @Melchior: is it possible to add an instrument, which shows the lateral movement of the helicopter or the direction of the translation? Probably yes. Have to look. We've had someone post a photo of what we identified as drift indicator. (Josh?) (There is a small bug in the movement of the blades. Due to gyro effects the rotor reacts (about) 90 delayed. If you put the stick forward, the left blade will decrease incidence). In the animation only, and With the CVS version? There was a bug that I fixed after the 0.9.10 release, I think. Or an FDM bug? Yes, only in animation. I think the bug is in the 0.9.10 release and in the cvs version m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel Maik Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
* Maik Justus -- Saturday 24 June 2006 00:29: Melchior FRANZ schrieb: Look into Mathias' ground cache. This should make it quite easy to get the necessary altitudes quickly. I will have a look on this. Is this used in yasim? Yes. It's use to get cheap terrain intersections for the gear. Yes, there is an R22, and Josh works on a CH53. Both not in CVS. )The R22 probably won't ever.) good (more helicopters) and bad (not in cvs) I'm confident that the CH53 will be submitted for cvs. :-) In the animation only, and With the CVS version? There was a bug that I fixed after the 0.9.10 release, I think. Or an FDM bug? Yes, only in animation. I think the bug is in the 0.9.10 release and in the cvs version Oh, whoops. Then it worked before, and it's my fix that broke it?! I'll look into it and send you a (reverse) patch for testing. m. Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Helicopter: First Impressions
Martin Spott wrote: Josh Babcock wrote: I like your todo list. I would just suggest one more thing. If you look at a helo from behind, the rotor disk will be canted slightly to one side in straight and level flight. The side force offsets the side force of the tail rotor to prevent sideslip. In FG, instead of the rotor disk being tilted to the left a few degrees, the whole aircraft is. This might very well be a phenomenon that's unique to helicopters which are based on this hingeless rotor concept, aircraft and rotor mostly move as one entity. They vary significantly from the typical Bell rotor style: http://www.christoph31.de/cgi-bin/MasterFrameReunion.cgi?http%3A//www.christoph31.de/foto/details.php%3Fimage_id%3D590%26 Martin. Yeah, this behavior may be appropriate for the bo105, I have a picture of an EC-135 with a semi-rigid rotor in a 1 hover that has that has that same tilt, though it might have just been wiggling as it lifted off. Most of the rotors out there, however, are still fully articulated. There are even a significant number of teetering rotors still flying. Just about every Jet Ranger has one. It is definitely not right for them. As far as I can tell, YASim treats all rotors this way. Josh Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnkkid=120709bid=263057dat=121642 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
