AttachedComponent¶
AttachedComponent is the class where all the other components on ADR inherit from. Together with the FreeBody class it allows one to create a complex network of components that interact to calculate their states.
An AttachedComponent will have properties that identify its parent component and its position and angle relative to this parent.
By definition an AttachedComponent should always have a parent component, as its states will be calculated using it (eg.: self.angle = self.parent.angle + self.relative_angle). This parent component can be another AttachedComponent or a FreeBody. On the top of the component's network there should always be a FreeBody, where the main states (position, angle, velocity and ambient) will be set.
The AttachedComponent class implements three properties and a state, being those parent, relative_position, relative_angle, velocity and actuation_angle.
Instantiation¶
To instantiate a AttacheComponent one needs to pass the arguments of its parent class (name, type and mass) and also its own (relative_position and relative_angle). The parent property is set with the special method set_parent afterwards.
The relative_position property should be a 2D vector (using vec.Vector2 class) that represents the position of the component's origin relative to its parent origin (both origins being arbitrary and defined by the user).
The relative_angle property should be a float representing the angle of the component relative to its parent, in radians and clockwise.
from adr.Components import FreeBody, AttachedComponent
from adr.World import Ambient
from vec import Vector2
import math
env = Ambient()
plane = FreeBody(
name='plane',
type='vehicle',
mass=2.0,
position_cg=Vector2(x=-0.05, y=0),
pitch_rot_inertia=30.0,
ambient=env
)
wing = AttachedComponent(
name='wing',
type='wing',
mass=0.3,
relative_position=Vector2(x=-0.15, y=0.2),
relative_angle=math.radians(6),
)
aileron = AttachedComponent(
name='left_aileron',
type='aileron',
mass=0.02,
relative_position=Vector2(x=-0.3, y=0),
relative_angle=math.radians(4),
)
wing.set_parent(plane)
aileron.set_parent(wing)
print(math.degrees(wing.angle))
>>> 6.0
print(math.degrees(aileron.angle))
>>> 10.0
plane.angle = math.radians(5)
print(math.degrees(aileron.angle))
>>> 14.99999999999
position property¶
This property returns the absolute position vector of the component
wing.set_parent(plane)
plane.angle = 8
print(wing.position)
>>>Vector2 (-0.17604664425338434, -0.17750374375522998)
ambient property¶
This property returns the environment in which the component is located
print(wing.ambient)
>>> adr.World.Ambient.Ambient object at 0x000001E4F70128E0
velocity property¶
This property returns the speed of the component based on the speed of the parent component
wing.set_parent(plane)
plane.velocity = Vector2(10, 20)
print(wing.velocity)
>>> Vector2 (10, 20)
reset_state method¶
The reset_state method will reset all the component state variables (actuation_angle), and call BaseComponent's reset_state after, which will reset the state of all child components.
plane.angle = math.radians(8)
print(math.degrees(plane.angle))
>>> 8.0
plane.reset_state()
print(math.degrees(plane.angle))
>>> 0.0
```##Angle:
The property angle will return to you the angle that the given component is set.
Let's say we have a component 'Wing' attached to the body of the plane, that is set as a FreeBody Component called 'Plane'. The property angle will take in count the plane angle and the relative angle of the wing, just as shown in the example below:
``` python
env = Ambient()
plane = FreeBody(
name='plane',
type='vehicle',
mass=2.0,
angle = math.radians(3.2),
position_cg=Vector2(x=-0.05, y=0),
pitch_rot_inertia=30.0,
ambient=env
)
wing = AttachedComponent(
name='wing',
type='wing',
mass=0.3,
relative_position=Vector2(x=-0.15, y=0.2),
relative_angle = math.radians(1)
)
print(math.degrees(wing.angle))
>>> 4.2
If the given component has an actuation angle, the property will return the angle with the maximum actuation angle as well.
Let's use another example to demonstrate that: an aileron is attached to the wing, with an actuation angle of 15 degrees and a relative angle of 0 degrees.
aileron = AttachedComponent(
name='left_aileron',
type='aileron',
mass=0.02,
relative_position=Vector2(x=-0.3, y=0),
relative_angle=math.radians(0),
)
aileron.actuation_angle(math.radians(15))
aileron.set_parent(wing)
print(math.degrees(aileron.angle))
>>> 19.2
Set_parent¶
The set_parent has already been used in the example above, but to give a further explanation, what the function does is to set a parent to the current component.
Note that if we try to set a parent to a component that has already a parent assigned it will return an error. In the example above, the aileron parent is the wing, see what happens if we try to set the plane as the aileron parent:
aileron.set_parent(plane)
>>> raise Exception('Component already has a parent: wing')