3DOF (Body Axes)
A model of planar longitudinal motion.
Description
The 3DOF (Body Axes) block realises a model of the plane longitudinal motion of an aircraft taking into account the rotation of the vertical plane of the associated coordinate system with respect to the earth coordinate system.
The equations of motion have the form:
The 3DOF (Body Axes) unit works in SI units.
| The block uses coordinate systems according to the international standard ISO 1151. |
Ports
Input
Fx (N) - projection of the applied force on the OX axis
scalar
Projection of the applied force on the axis of the associated coordinate system, N.
Data types: Float64.
Fz (N) - projection of the applied force on the OZ axis
scalar
Projection of the applied force on the axis of the associated coordinate system, N.
Data types: Float64.
M (N-m) - pitching moment
scalar
Pitching moment, N⋅m.
Data types: Float64.
Output
θ (rad) - pitch angle
scalar
Pitch angle, rad. The value is in the range .
Data types: Float64.
q (rad/s) - pitch rate
scalar
Pitch velocity, rad/s.
Data types: Float64.
dq/dt (rad/s2) - change in pitch rate
scalar
Change in pitch rate, rad/s2^.
Data types: Float64.
Xe Ze (m) - position relative to the earth’s coordinate system
`vector 2 by 1
Coordinates of the aircraft relative to the Earth coordinate system, m. Defined as a vector.
Data types: Float64.
U w (m/s) - aircraft speed
`vector 2 by 1
Components of the aircraft velocity along the axes and respectively, m/s. They are set in the form of a vector.
Data types: Float64.
Axb Azb (m/s2) is the acceleration of the aircraft in the associated coordinate system
`vector 2 by 1
Components of the aircraft acceleration in the linked coordinate system along the and axes respectively, m/s2. Defined as a vector.
Data types: Float64.
Axe Aze (m/s2) - acceleration of the aircraft relative to the Earth’s coordinate system
`vector 2 by 1
Components of the aircraft acceleration relative to the Earth coordinate system along the axes и respectively, m/s2. The components of the aircraft acceleration relative to the Earth’s coordinate system in the axes and respectively, m/s2.
Data types: Float64.
Parameters
Initial velocity - initial airspeed
100.0 (by default) | scalar
Initial airspeed of the aircraft, rad/s.
Initial body attitude - initial pitch angle
0.0 (by default) | scalar.
Initial pitch angle, rad.
Initial body rotation rate - initial pitch rate change
0.0 (by default) | scalar.
Initial pitch rate change, rad/s2.
Initial incidence - initial angle of attack
0.0 (By default) | scalar.
Initial angle of attack, rad.
Initial position (x,z) - initial position relative to the Earth coordinate system
[0.0,0.0] (by default) | vector 2 to 1
Initial coordinates of the aircraft relative to the Earth coordinate system, m. Set as a vector.
Initial mass - mass
1.0 (by default) | scalar.
Mass of the aircraft, kg.
Inertia - moment of inertia
1.0 (by default) | scalar.
Moment of inertia of the aircraft relative to the axis , kg⋅m2.
Acceleration due to gravity - free fall acceleration
9.81 (By default) | scalar.
Free-fall acceleration, m/s2. The value may be zero if the effect of gravity on the aircraft can be neglected.