Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
On mar 13 novembre 2007, Georg Vollnhals wrote: Hi Gérard, although your H 21 flies very nice (and has an exellent 3D-model, eye-candy!) I have the same yaw-problem - reaction is very slow and damped. This makes procedures nearly impossible like going down to your selected landing-area against the wind, then turning (yaw-axis) the helo at very low height (very low speed or hovering) to fit your landing-place. Once again, I do know not so much about real-life tandem-rotor helicopter flight behaviour, it is just common sense that this low-yaw-reaction/low-yaw-power is somehow noticeable. Georg Hello Georg, Thanks for your feedback. I conclude that i have to do more and more tuning. May be with that existing great helicopter yasim code source from Maik we have reach the limit. My previous mail was mainly to say that i could notice some actions (good or bad) from the ballast definition to the fly quality. My first tests were crazy (helicopter sliding on the side, and a huge yaw problem), the helicopter was unable to fly straight ahead. May be the yaw problem is only due to that ballast definition, may be there is some more complex interactions. Could be an open Question :) Cheers -- Gérard http://pagesperso-orange.fr/GRTux/ - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
Hi Gérard, gerard robin schrieb am 13.11.2007 12:59: On mar 13 novembre 2007, Georg Vollnhals wrote: Hi Gérard, although your H 21 flies very nice (and has an exellent 3D-model, eye-candy!) I have the same yaw-problem - reaction is very slow and damped. This makes procedures nearly impossible like going down to your selected landing-area against the wind, then turning (yaw-axis) the helo at very low height (very low speed or hovering) to fit your landing-place. Once again, I do know not so much about real-life tandem-rotor helicopter flight behaviour, it is just common sense that this low-yaw-reaction/low-yaw-power is somehow noticeable. Georg Hello Georg, Thanks for your feedback. I conclude that i have to do more and more tuning. May be with that existing great helicopter yasim code source from Maik we have reach the limit. no, I am sure that don't reached any limit here. My previous mail was mainly to say that i could notice some actions (good or bad) from the ballast definition to the fly quality. My first tests were crazy (helicopter sliding on the side, and a huge yaw problem), the helicopter was unable to fly straight ahead. May be the yaw problem is only due to that ballast definition, may be there is some more complex interactions. The yaw problem is rather complex. It is the result of tilting one rotor to one side and the other to the opposite direction. This results in a yaw-moment on the fuselage. The resulting yaw rotation depends on many parameters: - the tilt angle of the rotors (which depends on the CYCLICAIL control input and min-, maxcyclicail, on delta3, rellenflaphinge, relbladecenter, weightperblade, the airfoil parameters, delta, cyclic-factor, and the blade geometry; most of these parameters we do not know.) - the interaction of the downwash (and remaining air) with the (rotating) fuselage, gears and stabs (downwashfactor, yasimdragfactor, yasimliftfactor, geometry of fuselage, gears and stabs) - the weight distribution (the gravity tensor) of the whole helicopter. Unfortunately these parameters are not independent of each other and some of them are not linear (and for some the derivation changes the sign) And we even do not know, which is the maximum yaw-rate of the real helicopter. Conclusion: The yaw rate is one of the complexest values simulating a tandem helicopter. Could be an open Question :) Cheers Regards, Maik - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
Hi gérard, Great helicopter. Nice addon to flightgear. By the way: Watching the HUP I got aware, that there is a problem with the animation of the flapping angle of the blades. The problem is the missing documentation of the output of the the rotor simulation in the property tree. If position-deg is 0, then the blade is pointing backwards (and to be honest, I thought it means it points forward :-( ) The animation assumes, that position-deg == 0 means the blade is pointing forward. Therefore the tilting of the rotor seem to be inversed. The rotation needs a 180deg offset. (by adding another 180deg offset to the yasim-xml file (phi0 = 0) the starting position of the rotor would remain the same). The same is necessary at the H-21. I think I need to improve the documentation in that point... Maik gerard robin schrieb am 12.11.2007 02:48: Hello An other model of an ancestor helicopter, the HUP Retriever ,which was developed by Piasecki, is available on CVS. It was a rescue helicopter, with To provide rescue without crew assistance, a door (under the copilot seat) , available after folding the copilot’s seat forward, opened through which a rescue sling could be lowered from an overhead winch. That helicopter was used by the U.S. Navy and Army (from 1949 to 1964), it was also delivered to the Canadian and French Navies (in service from 1953 to 1965) The model is under construction. The FDM is a guess. Mainly to do: -the instruments, -the landing gear animations -liveries variant Here snapshots http://pagesperso-orange.fr/GRTux/HUP-img1.jpg http://pagesperso-orange.fr/GRTux/HUP-img2.jpg Cheers - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
On lun 12 novembre 2007, Maik Justus wrote: Hi gérard, Great helicopter. Nice addon to flightgear. By the way: Watching the HUP I got aware, that there is a problem with the animation of the flapping angle of the blades. The problem is the missing documentation of the output of the the rotor simulation in the property tree. If position-deg is 0, then the blade is pointing backwards (and to be honest, I thought it means it points forward :-( ) The animation assumes, that position-deg == 0 means the blade is pointing forward. Therefore the tilting of the rotor seem to be inversed. The rotation needs a 180deg offset. (by adding another 180deg offset to the yasim-xml file (phi0 = 0) the starting position of the rotor would remain the same). The same is necessary at the H-21. I think I need to improve the documentation in that point... Maik Hello Maik, Does that position-deg == 0 inverted, specific to HUP and H-21 or a generic problem to any helicopter which blade Zero is drawn pointing forward ? The S-51 could have the same error, and looking at the nice new CH47 it seems to want the 180 offset. I did not checked the others choppers. Cheers -- Gérard http://pagesperso-orange.fr/GRTux/ - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
Hello Gerard, it's generic. I need to check, which helicopters are doing it correct and which helicopters are doing it as one would expect (0 deg = forward) and which helicopters do not depend on this flapping angle (you can use cone-deg, roll-deg and cone-deg instead). Maybe it is easier to modify the source than to modify many helicopters. Maik gerard robin schrieb am 13.11.2007 01:39: On lun 12 novembre 2007, Maik Justus wrote: Hi gérard, Great helicopter. Nice addon to flightgear. By the way: Watching the HUP I got aware, that there is a problem with the animation of the flapping angle of the blades. The problem is the missing documentation of the output of the the rotor simulation in the property tree. If position-deg is 0, then the blade is pointing backwards (and to be honest, I thought it means it points forward :-( ) The animation assumes, that position-deg == 0 means the blade is pointing forward. Therefore the tilting of the rotor seem to be inversed. The rotation needs a 180deg offset. (by adding another 180deg offset to the yasim-xml file (phi0 = 0) the starting position of the rotor would remain the same). The same is necessary at the H-21. I think I need to improve the documentation in that point... Maik Hello Maik, Does that position-deg == 0 inverted, specific to HUP and H-21 or a generic problem to any helicopter which blade Zero is drawn pointing forward ? The S-51 could have the same error, and looking at the nice new CH47 it seems to want the 180 offset. I did not checked the others choppers. Cheers - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
On mar 13 novembre 2007, Maik Justus wrote: Hello Gerard, it's generic. I need to check, which helicopters are doing it correct and which helicopters are doing it as one would expect (0 deg = forward) and which helicopters do not depend on this flapping angle (you can use cone-deg, roll-deg and cone-deg instead). Maybe it is easier to modify the source than to modify many helicopters. Maik Hello Maik, To me, i have done a modular .xml and drawing .ac file system, so i can modify easily, theses animations, or to add another 180deg offset to the yasim-xml file (phi0 = 0) , like you told me. No problem :) Cheers -- Gérard http://pagesperso-orange.fr/GRTux/ - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
Hi Maik, now as we have several tandem-rotor helicopters I would like to ask wheather the yaw-axis treatment of the helo flightmodel is satisfying or has to be polished up a little. Or if this is just up to the creator of such a helo how to implement better. As for the nice HUP I can get some yaw movement but only if I apply *full* pedal either left or right (and the reaction is pretty tame and only when hovering/at very low speed). The CH47 reacts a little better but has a heavy roll tendency when pedal is used, strange for me as this helo is said to be very stable when doing tasks like logging (civil version, Columbia helicopter). Just a question what you are thinking about this :-) Thank you for your reply. Regards Georg EDDW - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
On mar 13 novembre 2007, Georg Vollnhals wrote: Hi Maik, now as we have several tandem-rotor helicopters I would like to ask wheather the yaw-axis treatment of the helo flightmodel is satisfying or has to be polished up a little. Or if this is just up to the creator of such a helo how to implement better. As for the nice HUP I can get some yaw movement but only if I apply *full* pedal either left or right (and the reaction is pretty tame and only when hovering/at very low speed). The CH47 reacts a little better but has a heavy roll tendency when pedal is used, strange for me as this helo is said to be very stable when doing tasks like logging (civil version, Columbia helicopter). Just a question what you are thinking about this :-) Thank you for your reply. Regards Georg EDDW Hello Georg, You are right and probably, Maik could give us some better tuning. However when doing the H-21 FDM i could notice that we get some diff about the yaw reaction, according to the values and position of the ballast (with respect in any case of the CG position), and the best we get with yaw gives the best on the ground position, i mean the helicopter does not slide on the side. I do not pretend that the H-21 is right, it is only a remark :) . I am working on the HUP in order to get the same result. Cheers -- Gérard http://pagesperso-orange.fr/GRTux/ - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] HUP Retriever , an other Piasecki helicopter
gerard robin schrieb: Hello Georg, You are right and probably, Maik could give us some better tuning. However when doing the H-21 FDM i could notice that we get some diff about the yaw reaction, according to the values and position of the ballast (with respect in any case of the CG position), and the best we get with yaw gives the best on the ground position, i mean the helicopter does not slide on the side. I do not pretend that the H-21 is right, it is only a remark :) . I am working on the HUP in order to get the same result. Cheers Hi Gérard, although your H 21 flies very nice (and has an exellent 3D-model, eye-candy!) I have the same yaw-problem - reaction is very slow and damped. This makes procedures nearly impossible like going down to your selected landing-area against the wind, then turning (yaw-axis) the helo at very low height (very low speed or hovering) to fit your landing-place. Once again, I do know not so much about real-life tandem-rotor helicopter flight behaviour, it is just common sense that this low-yaw-reaction/low-yaw-power is somehow noticeable. Georg - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] HUP Retriever , an other Piasecki helicopter
Hello An other model of an ancestor helicopter, the HUP Retriever ,which was developed by Piasecki, is available on CVS. It was a rescue helicopter, with To provide rescue without crew assistance, a door (under the copilot seat) , available after folding the copilot’s seat forward, opened through which a rescue sling could be lowered from an overhead winch. That helicopter was used by the U.S. Navy and Army (from 1949 to 1964), it was also delivered to the Canadian and French Navies (in service from 1953 to 1965) The model is under construction. The FDM is a guess. Mainly to do: -the instruments, -the landing gear animations -liveries variant Here snapshots http://pagesperso-orange.fr/GRTux/HUP-img1.jpg http://pagesperso-orange.fr/GRTux/HUP-img2.jpg Cheers -- Gérard http://pagesperso-orange.fr/GRTux/ - This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now http://get.splunk.com/ ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
