LIBRARY
PlanarMechanics.PrescribedAcceleration
Prescribed acceleration of frame_b via input connectors.
The absolute acceleration of frame_b is driven by the two real inputs a_x, a_y, resolved in the planar world frame. Velocity and position are obtained by integrating the acceleration inputs, starting from v_start and r_start respectively.
When fixed_orientation is true, the rotation angle is locked to zero. When false, no orientation constraint is imposed and no torque is applied — the orientation must be determined by connected components.
Usage
MultibodyComponents.PlanarMechanics.PrescribedAcceleration(r_start=[0, 0], v_start=[0, 0])
Parameters:
| Name | Description | Units | Default value |
|---|---|---|---|
fixed_orientation | – | true | |
statePriority | – | 2 | |
r_start | Initial position vector from world frame to frame_b, resolved in world frame | m | [0, 0] |
v_start | Initial absolute velocity of frame_b, resolved in world frame | m/s | [0, 0] |
Connectors
frame_b- Coordinate system (2-dim.) fixed to the component with one cut-force and cut-torque.
All variables are resolved in the planar world frame. (Frame2D)
a_x- This connector represents a real signal as an input to a component (RealInput)a_y- This connector represents a real signal as an input to a component (RealInput)
Variables
| Name | Description | Units |
|---|---|---|
r | Position vector from world frame to frame_b, resolved in world frame | m |
v | Absolute velocity of frame_b, resolved in world frame | m/s |
a | Absolute acceleration of frame_b, resolved in world frame | m/s2 |
Behavior
Dict{MIME{Symbol("text/plain")}, String} with 1 entry: MIME type text/plain => "Error displaying result"
Source
dyad
"""
Prescribed acceleration of `frame_b` via input connectors.
The absolute acceleration of `frame_b` is driven by the two real inputs `a_x`, `a_y`,
resolved in the planar world frame. Velocity and position are obtained by integrating
the acceleration inputs, starting from `v_start` and `r_start` respectively.
When `fixed_orientation` is true, the rotation angle is locked to zero.
When false, no orientation constraint is imposed and no torque is applied —
the orientation must be determined by connected components.
"""
component PrescribedAcceleration
frame_b = Frame2D() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": 900, "y1": 450, "x2": 1000, "y2": 550, "rot": 0}
},
"tags": []
}
}
a_x = RealInput() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": -50, "y1": 250, "x2": 50, "y2": 350, "rot": 0}
},
"tags": []
}
}
a_y = RealInput() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": -50, "y1": 650, "x2": 50, "y2": 750, "rot": 0}
},
"tags": []
}
}
structural parameter fixed_orientation::Boolean = true
structural parameter statePriority::Integer = 2 # Higher than plain body variables so that the initialized, prescribed variables become the selected states
"Initial position vector from world frame to frame_b, resolved in world frame"
parameter r_start::Position[2] = [0, 0]
"Initial absolute velocity of frame_b, resolved in world frame"
parameter v_start::Velocity[2] = [0, 0]
"Position vector from world frame to frame_b, resolved in world frame"
variable r::Position(statePriority = statePriority, initial = r_start)[2]
"Absolute velocity of frame_b, resolved in world frame"
variable v::Velocity(statePriority = statePriority, initial = v_start)[2]
"Absolute acceleration of frame_b, resolved in world frame"
variable a::Acceleration[2]
relations
a = [a_x, a_y]
frame_b.x = r[1]
frame_b.y = r[2]
der(r) = v
der(v) = a
if fixed_orientation
frame_b.phi = 0
else
frame_b.tau = 0
end
metadata {
"Dyad": {
"icons": {"default": "dyad://MultibodyComponents/PrescribedAcceleration.svg"},
"labels": [
{
"label": "$(instance)",
"x": 500,
"y": 150,
"rot": 0,
"attrs": {"font-size": "160"}
}
]
}
}
endFlattened Source
dyad
"""
Prescribed acceleration of `frame_b` via input connectors.
The absolute acceleration of `frame_b` is driven by the two real inputs `a_x`, `a_y`,
resolved in the planar world frame. Velocity and position are obtained by integrating
the acceleration inputs, starting from `v_start` and `r_start` respectively.
When `fixed_orientation` is true, the rotation angle is locked to zero.
When false, no orientation constraint is imposed and no torque is applied —
the orientation must be determined by connected components.
"""
component PrescribedAcceleration
frame_b = Frame2D() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": 900, "y1": 450, "x2": 1000, "y2": 550, "rot": 0}
},
"tags": []
}
}
a_x = RealInput() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": -50, "y1": 250, "x2": 50, "y2": 350, "rot": 0}
},
"tags": []
}
}
a_y = RealInput() {
"Dyad": {
"placement": {
"diagram": {"iconName": "default", "x1": -50, "y1": 650, "x2": 50, "y2": 750, "rot": 0}
},
"tags": []
}
}
structural parameter fixed_orientation::Boolean = true
structural parameter statePriority::Integer = 2 # Higher than plain body variables so that the initialized, prescribed variables become the selected states
"Initial position vector from world frame to frame_b, resolved in world frame"
parameter r_start::Position[2] = [0, 0]
"Initial absolute velocity of frame_b, resolved in world frame"
parameter v_start::Velocity[2] = [0, 0]
"Position vector from world frame to frame_b, resolved in world frame"
variable r::Position(statePriority = statePriority, initial = r_start)[2]
"Absolute velocity of frame_b, resolved in world frame"
variable v::Velocity(statePriority = statePriority, initial = v_start)[2]
"Absolute acceleration of frame_b, resolved in world frame"
variable a::Acceleration[2]
relations
a = [a_x, a_y]
frame_b.x = r[1]
frame_b.y = r[2]
der(r) = v
der(v) = a
if fixed_orientation
frame_b.phi = 0
else
frame_b.tau = 0
end
metadata {
"Dyad": {
"icons": {"default": "dyad://MultibodyComponents/PrescribedAcceleration.svg"},
"labels": [
{
"label": "$(instance)",
"x": 500,
"y": 150,
"rot": 0,
"attrs": {"font-size": "160"}
}
]
}
}
endTest Cases
No test cases defined.
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