Register to reply 
Precise definition of yaw 
Share this thread: 
#1
Jul1511, 03:15 PM

P: 7

I'm googled "yaw" for the afternoon and there is a detail that I'm not finding. *One* of my understanding of yaw from my readings is that it is the angle between two /vertical/ planes, one containing the velocity of the moving object and the other containing "longitudinal" axis of the moving object i.e. the fronttotail axis of the fuselage of an aircraft.
This is my own cobbled together idea of waht yaw could *possibly* mean. Nowhere is yaw defined exactly in these terms. Instead, yaw is explained in terms of rotation around the vertical axis, where it sometimes seems that vertical axis refers to the "longitudinal" axis, and somtimes it seems to refer the gravity vector. For now, I assumed the latter. Even so, there is the question of precisely how to measure the angle between the velocity vector and the direction in which the moving object is facing. The possibilities that come to mind are: 1. Just measure the angle between the two. 2. Both vectors projected onto a completely horizontal plane 3. Both vectors projected onto a plane containing (1) the velocity vector and (2) the intersection of the horizontal plane with the plane that is perpedicular to the velocity vector. 4. Both vectors projected onto a plane containing (1) the "longitudinal" vector and (2) the intersection of the horizontal plane with the plane that is perpedicular to the "longitudinal" vector. 5. Both vectors are projected onto the plane containing (1) the "longitudinal" axis and (2) the wingtiptowingtip axis. Thanks for any clarification 


#2
Jul1511, 04:23 PM

Emeritus
Sci Advisor
HW Helper
Thanks
PF Gold
P: 6,559

How about this link:
http://www.grc.nasa.gov/WWW/K12/airplane/yaw.html It's got pitchers and an illustrative animation. 


#3
Jul1511, 04:40 PM

P: 7

I did run across that....it doesn't really say, but it looks like the yaw axis is also perpendicular to the longitudinal access of the plane. This would mean it is completely unrelated to the direction of gravity (which contradicts previous material I've read elsewhere). Is that correct?



#4
Jul1511, 09:39 PM

Emeritus
Sci Advisor
HW Helper
Thanks
PF Gold
P: 6,559

Precise definition of yaw
For rigid body motion, there are 6 degrees of freedom: 3 in translation and 3 in rotation.
Imagine a body like an airplane. Let's assume that the xaxis runs along the center of the fuselage. The yaxis would run perpendicular to the xaxis from wing tip to wing tip. The zaxis is perpendicular to the xy plane. The 3 translational degrees of freedom are as follows (direction of motion as indicated): x: Surge y: Sway z: Heave The rotational degrees of freedom (and the axis about which motion takes place) are: x: Roll y: Pitch z: Yaw 


#5
Jul1611, 07:10 AM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 39,569

Normally, yes, "yaw" is rotation about a vertical axis. A more general definition is SteamKing's: given an arbitrary set of three mutually perpedicular axes, which we arbitrarily call "x", "y", and "z", think of a ship or airplane aligned along the xaxis with its beam (or wings for an airplane) in the direction of the yaxis. Then "roll" is rotation about the xaxis, "pitch" is rotation about the yaxis, and "yaw" is rotation about the zaxis.



#6
Jul1811, 08:59 AM

P: 7




#7
Jul1811, 09:03 AM

P: 7




#8
Jul1911, 09:33 AM

P: 273




Register to reply 
Related Discussions  
In binary can we have a value with deci centi mili or more lower valued prefix?  Computers  14  
What is the Precise Meaning of Canonical in Quantum Gravity Context  Beyond the Standard Model  3  
Definition of black hole for the purposes of nohair theorems?  Special & General Relativity  3  
Does quantum mechanical definition of momentum require movement ?  Quantum Physics  21  
A real number definition involving BruijnNewmann constant..  Linear & Abstract Algebra  6 