[Flightgear-devel] autopilot system
My question is about the variables that are used in the autopilot system. As far as I can understand the target heading is calculated by the angle between the aircraft and the waypoint with the proper heading and the rate of change of angle times the distance between the coordinates which are summed together. The aircraft is supposed to possess max roll until it reaches the rollout point where linearisation occurs to find target roll and aileron commands. However I didn't understand how max roll is calculated. Is it the roll angle that aircraft stands stable without stall (ie. the angle for minimum turn radius) or a value chosen for the aircraft. The second one sounds more logical to me because when the lateral distance is large to reach a navigation point we can't turn with the roll value for minimum turn radius if we don't want to make circles while reaching our point so how can it be calculated. In one of the documents in the flight gear site I found that the rollout point which resembles an angle is approximately same with the maxroll which is taken 20 for Chessna and the rollout smooth point is approximately half of its maxroll angle. Are these ratios true for other aircraft or they are values found by certain handy equations that are dependant to the coefficients of the aircraft which is the main thing that I am wondering and want to learn about because I am trying to experiment with different aircraft by changing the values in the config files and try to make a realistic stuff while having fun and learning about aviation.
[Flightgear-devel] configuration files.
Do you use any program to calculate the coefficients of rolling, pitching,yawing moments and the drag, lift and sideforce coefficients. The conf file of Cessna seemed so complete containing all of those coefficients. I am trying to change the aircraft properties for different types of airplanes to observe and understand flight dynamics better that would help me in collage but I couldn't find any program to calculate those coefficients. I heard x-plane which calculates some properties but I couldn't figure out their configuration files.
[Flightgear-devel] external fdm
I have downloaded a matlab-simulink program that uses flightgear interface. For a flight dynamics model it requires external fdm so I command from that program and visualise in flight gear. My question is how can I change the flight dynamics model to the external type. I read that batch file and command shell can do this job. how can I use it in windows. I am used to clicking with the mouse how can I open a command shell.
[Flightgear-devel] changing aircraft
my operating system is windows milenium and I tried to change my aircraft via entering flight\FlightGear\runfgfs.bat ''--aircraft=4a-yasim'' into the start\run directory but the simulation didn't start. "You can also pass command line options from Sec. 4 to the batch file (if running it form a Command shell). However, you have to enclose them in double quotes." writes in the install guide. What is the batch file is it the runfgfs.bat and the command shell is the run directory. If it is my setting had to work. I want to change the default fdm to external for a program that I downloaded to control the simulation and I also want to fly with different aircrafts. Can you please give me an example. The example might also be in dos too if it can work like this.
[Flightgear-devel] command line parameters
my operating system is windows milenium and I tried to change my aircraft via entering flight\FlightGear\runfgfs.bat ''--aircraft=4a-yasim'' into the start\run directory but the simulation didn't start. "You can also pass command line options from Sec. 4 to the batch file (if running it form a Command shell). However, you have to enclose them in double quotes." writes in the install guide. What is the batch file is it the runfgfs.bat and the command shell is the run directory. If it is my setting had to work. I want to change the default fdm to external for a program that I downloaded to control the simulation and I also want to fly with different aircrafts. Can you please give me an example. The example might also be in dos too if it can work like this. _ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?page=features/virus ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] engine coefficient
Firstly I want to thank you for your help in my understanding of the aerodynamic structure of the aircrafts. I have two questions about the aerodynamics model firstly I have a program that calculates lift and drag versus attack angle coefficients for a given parameterised airfoil and is it enough for me to modify the config file lift due to alpha table Is there any way to calculate thrust and the engine's effects on the aerodynamics coefficients of Cx, Cy, Cz and roll pitch and yaw coefficients. Is Cx that the engine produces is approximately equal to the thrust force that shares the same vector.
[Flightgear-devel] compilation of source code
I am trying to change some code in the flight gear modules and I have a great problem compiling it with mcrsoft visual c++. How can I compile the new code. I heard that makefiles can be used for compilation. Do they work in windows millenium. If you can direct me with some information I would be grateful. sorry for my never ending questions I am not educated in computer engineering and I am new to programming.
[Flightgear-devel] target heading
I have a couple of questions that I am not sure of about the calculation of target heading. is the nav heading the heading from the north or the difference between our aircrafts and the navigation points heading angles and is the nav radial the angle between the aircraft to the waypoint with the ''waypoint's'' true heading without taking the value of aircraft's heading so [(nav heading - nav radial)* distance = target heading?] Or is target heading the result of a differential function like the change of nav radial independant from aircraft's heading angle. If I am mistaken can you simply guide me about target heading. regards Mehmet _ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] target heading
I have a couple of questions that I am not sure of about the calculation of target heading. is the nav heading the heading from the north or the difference between our aircrafts and the navigation points heading angles and is the nav radial the angle between the aircraft to the waypoint with the ''waypoint's'' true heading without taking the value of aircraft's heading so [(nav heading - nav radial)* distance = target heading?] Or is target heading the result of a differential function like the change of nav radial independant from aircraft's heading angle. If I am mistaken can you simply guide me about target heading. regards Mehmet _ Help STOP SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] Heading needle deflection
Thank you for your reply and I began to understood the concepts of the heading hold system in nav mode but some of the autopilot system's properties are not so solid in my mind so I want to briefly summarase my understanding of the autopilot systems lateral navigation mode if there are mistakes which is probably the case you may tell me. Target heading is calculated by using ((nav heading - nav radial) x distance to the nav point) which is the adjustment part that I saw on newauto.cxx and target heading is target radial + adjustment. nav_heading is the heading difference between our plane's heading and the heading of the reference line which we want to align with for example the airport landing road for an ILS system which is commented out in source as // determine our current radial position relative to the // navaid in "true" heading. cur_radial = current_radiostack->get_nav1_heading(); Nav radial is the angle between the reference line with that line's heading and the line from the plane to the ILS or VOR antenna no matter what the plane's heading is which is commented as // determine the target radial in "true" heading The nav_radial seems to be the target radial in newauto.cxx, tgt_radial = current_radiostack->get_nav1_radial() and the heading needle deflection becomes the difference between our current heading and the line connecting our vehicle to the ILS antenna which is the line with the target radial and is handled in Cockpit/navcom.cxx as r = nav_heading - nav_radial; return r; for the needle deflection and in autopilot code in the comments it writes // determine the target heading to fly to intercept the // tgt_radial TargetHeading = tgt_radial + adjustment; In one of the mails I read something like At 5 miles X 2 degrees deviation it was commanding a 10 degree turn so the order given by code to the aircraft is to turn with the amount of difference equal to the adjustmant part calculated in the autopilot code from its current heading to intersect the target radial. Thanks _ Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] autopilot target heading
If the heading mode is FG_HEADINGWAY_POINT does autopilot block use
a similar procedure like in VOR or ILS navigation by using a rolling motion
to intersect waypoint in a pre-determined heading or does it use the angle
difference between its current heading and the heading calculated by the
waypoint's coordinates and fly to that heading without taking final heading
into account
In the source code I saw items like wp_course and wp_distance.
Target heading was adjusted to waypoint course such as:
if ( wp_distance > 100 ) {//I think it flies to a cetain
waypoint until it reaches the limit
TargetHeading = NormalizeDegrees(wp_course);
can you briefly describe how wp_course is calculated?
Regards
Mehmet
_
Protect your PC - get McAfee.com VirusScan Online
http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
___
Flightgear-devel mailing list
[EMAIL PROTECTED]
http://mail.flightgear.org/mailman/listinfo/flightgear-devel
