Cylindrical

Cylindrical joint (2 degrees-of-freedom, 4 potential states)

Diagram

Information

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

Joint where frame_b rotates around and translates along axis n which is fixed in frame_a. The two frames coincide when "phi=revolute.phi=0" and "s=prismatic.s=0". This joint has the following potential states;

  • The relative angle phi [rad] around axis n,
  • the relative distance s [m] along axis n,
  • the relative angular velocity w [rad/s] (= der(phi)) and
  • the relative velocity v [m/s] (= der(s)).

They are used as candidates for automatic selection of states from the tool. This may be enforced by setting "stateSelect=StateSelect.always" in the Advanced menu. The states are usually selected automatically. In certain situations, especially when closed kinematic loops are present, it might be slightly more efficient, when using the "StateSelect.always" setting.

In the following figure the animation of a cylindrical joint is shown. The light blue coordinate system is frame_a and the dark blue coordinate system is frame_b of the joint. The black arrow is parameter vector "n" defining the cylinder axis (here: n = {0,0,1}).

Parameters (4)

animation

Value: true

Type: Boolean

Description: = true, if animation shall be enabled (show cylinder)

n

Value: {1, 0, 0}

Type: Axis

Description: Cylinder axis resolved in frame_a (= same as in frame_b)

cylinderDiameter

Value: world.defaultJointWidth

Type: Distance (m)

Description: Diameter of cylinder

stateSelect

Value: StateSelect.prefer

Type: StateSelect

Description: Priority to use joint coordinates (phi, s, w, v) as states

Inputs (2)

cylinderColor

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

Type: Color

Description: Color of cylinder

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 a fixed to the component with one cut-force and cut-torque

frame_b

Type: Frame_b

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

Components (4)

world

Type: World

prismatic

Type: Prismatic

revolute

Type: Revolute

cylinder

Type: Shape