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JSBSim GroundReactions: Difference between revisions
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→Physical Characteristics: explanation of the reason contact points in JSBSim don't correspond with the contact points in the physical model
(→Configuration File Format:: explanation of square vs linear damping) |
(→Physical Characteristics: explanation of the reason contact points in JSBSim don't correspond with the contact points in the physical model) |
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#*Furthermore the BOGEY type includes features which are typical to landing gears such as brake and steering. | #*Furthermore the BOGEY type includes features which are typical to landing gears such as brake and steering. | ||
#X, Y, Z location, in inches in structural coordinate frame | #X, Y, Z location, in inches in structural coordinate frame | ||
#*It may require experimentation to determine the X,Y,Z coordinates to use for contact points that will correspond to the same points on your visual model and look right. Just for example, if bottom of the left landing gear is located at 20,40,-60 on your model, locating the JSBSim contact point at 20,40,-60 while most likely result in your landing gear appearing to be underground when the aircraft is on the runway. The reason is that if you have set the <spring_coeff> for the contact point to be, say, 200 LBS/FT and the landing gear has 400 LBS of force on it, it will be compressed by 2 FT--and thus in a spot 2 FT upwards from the point you specified. Generally you will need to specify your contact points some distance outwards from the aircraft body itself to compensate for this--a bit below the actual location of the landing gear, above the top of the fuselage, etc. The exact amount will depend on your <spring_coeff> and the characteristics of your aircraft. | |||
#Spring constant, in lbs/ft | #Spring constant, in lbs/ft | ||
#Damping coefficient, in lbs/ft/sec for linear damping or lbs/ft/sec^2 for square damping | #Damping coefficient, in lbs/ft/sec for linear damping or lbs/ft/sec^2 for square damping | ||