FixedRotation

Fixed translation followed by a fixed rotation of frame_b with respect to frame_a

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Component for a fixed translation and fixed rotation of frame_b with respect to frame_a, i.e., the relationship between connectors frame_a and frame_b remains constant. There are several possibilities to define the orientation of frame_b with respect to frame_a:

  • Planar rotation along axis 'n' (that is fixed and resolved in frame_a) with a fixed angle 'angle'.
  • Vectors n_x and n_y that are directed along the corresponding axes direction of frame_b and are resolved in frame_a (if n_y is not orthogonal to n_x, the y-axis of frame_b is selected such that it is orthogonal to n_x and in the plane of n_x and n_y).
  • Sequence of three planar axes rotations. For example, "sequence = {1,2,3}" and "angles = {90, 45, -90}" means to rotate frame_a around the x axis with 90 degrees, around the new y axis with 45 degrees and around the new z axis around -90 degrees to arrive at frame_b. Note, that sequence={1,2,3} is the Cardan angle sequence and sequence = {3,1,3} is the Euler angle sequence.

By default, this component is visualized by a cylinder connecting frame_a and frame_b, as shown in the figure below. In this figure frame_b is rotated along the z-axis of frame_a with 60 degree. Note, that the two visualized frames are not part of the component animation and that the animation may be switched off via parameter animation = false.

Parts.FixedRotation

Parameters (18)

animation

Value: true

Type: Boolean

Description: = true, if animation shall be enabled

r

Value: {0, 0, 0}

Type: Position[3] (m)

Description: Vector from frame_a to frame_b resolved in frame_a

rotationType

Value: Modelica.Mechanics.MultiBody.Types.RotationTypes.RotationAxis

Type: RotationTypes

Description: Type of rotation description

n

Value: {1, 0, 0}

Type: Axis

Description: Axis of rotation in frame_a (= same as in frame_b)

angle

Value: 0

Type: Angle_deg (°)

Description: Angle to rotate frame_a around axis n into frame_b

n_x

Value: {1, 0, 0}

Type: Axis

Description: Vector along x-axis of frame_b resolved in frame_a

n_y

Value: {0, 1, 0}

Type: Axis

Description: Vector along y-axis of frame_b resolved in frame_a

sequence

Value: {1, 2, 3}

Type: RotationSequence

Description: Sequence of rotations

angles

Value: {0, 0, 0}

Type: Angle_deg[3] (°)

Description: Rotation angles around the axes defined in 'sequence'

shapeType

Value: "cylinder"

Type: ShapeType

Description: Type of shape

r_shape

Value: {0, 0, 0}

Type: Position[3] (m)

Description: Vector from frame_a to shape origin, resolved in frame_a

lengthDirection

Value: to_unit1(r - r_shape)

Type: Axis

Description: Vector in length direction of shape, resolved in frame_a

widthDirection

Value: {0, 1, 0}

Type: Axis

Description: Vector in width direction of shape, resolved in frame_a

length

Value: Modelica.Math.Vectors.length(r - r_shape)

Type: Length (m)

Description: Length of shape

width

Value: length / world.defaultWidthFraction

Type: Distance (m)

Description: Width of shape

height

Value: width

Type: Distance (m)

Description: Height of shape

extra

Value: 0.0

Type: ShapeExtra

Description: Additional parameter depending on shapeType (see docu of Visualizers.Advanced.Shape)

R_rel

Value: if rotationType == Types.RotationTypes.RotationAxis then Frames.planarRotation(Modelica.Math.Vectors.normalizeWithAssert(n), Cv.from_deg(angle), 0) else if rotationType == Types.RotationTypes.TwoAxesVectors then Frames.from_nxy(n_x, n_y) else Frames.axesRotations(sequence, Cv.from_deg(angles), zeros(3))

Type: Orientation

Description: Fixed rotation object from frame_a to frame_b

Inputs (2)

color

Default Value: Modelica.Mechanics.MultiBody.Types.Defaults.RodColor

Type: Color

Description: Color of shape

specularCoefficient

Default Value: world.defaultSpecularCoefficient

Type: SpecularCoefficient

Description: Reflection of ambient light (= 0: light is completely absorbed)

Connectors (2)

frame_a

Type: Frame_a

Description: Coordinate system fixed to the component with one cut-force and cut-torque

frame_b

Type: Frame_b

Description: Coordinate system fixed to the component with one cut-force and cut-torque

Components (4)

R_rel

Type: Orientation

Description: Fixed rotation object from frame_a to frame_b

world

Type: World

R_rel_inv

Type: Orientation

Description: Inverse of R_rel (rotate from frame_b to frame_a)

shape

Type: Shape

Used in Examples (6)

ForceAndTorque

Modelica.Mechanics.MultiBody.Examples.Elementary

Demonstrate usage of ForceAndTorque element

GyroscopicEffects

Modelica.Mechanics.MultiBody.Examples.Rotational3DEffects

Demonstrates that a cylindrical body can be replaced by Rotor1D model

PrismaticConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and two prismatic joints or constrained to environment

RevoluteConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and revolute joint or constrained to environment

SphericalConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and spherical joint or constrained to environment

UniversalConstraint

Modelica.Mechanics.MultiBody.Examples.Constraints

Body attached by one spring and universal joint or constrained to environment

Used in Components (2)

Cylinder

Modelica.Mechanics.MultiBody.Examples.Loops.Utilities

Cylinder with rod and crank of a combustion engine

CylinderBase

Modelica.Mechanics.MultiBody.Examples.Loops.Utilities

One cylinder with analytic handling of kinematic loop