Planar
Planar joint (3 degrees-of-freedom, 6 potential states)
Library
Modelica/Mechanics/MultiBody/Joints
Description
Joint where frame_b can move in a plane and can rotate around anaxis orthogonal to the plane. The plane is defined byvector n which is perpendicular to the plane and by vector n_x,which points in the direction of the x-axis of the plane.frame_a and frame_b coincide when s_x=prismatic_x.s=0,s_y=prismatic_y.s=0 and phi=revolute.phi=0. This joint has the followingpotential states:
- the relative distance s_x = prismatic_x.s [m] along axis n_x,
- the relative distance s_y = prismatic_y.s [m] along axis n_y = cross(n,n_x),
- the relative angle phi = revolute.phi [rad] around axis n,
- the relative velocity v_x (= der(s_x)).
- the relative velocity v_y (= der(s_y)).
- the relative angular velocity w (= der(phi))
They are used as candidates for automatic selection of statesfrom 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 planarjoint is shown. The light blue coordinate system isframe_a and the dark blue coordinate system isframe_b of the joint. The black arrows are parametervectors "n" and "n_x"(here: n = {0,1,0}, n_x = {0,0,1}, s_x.start = 0.5,s_y.start = 0.5, phi.start = 45o).
Parameters
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_animation | animation | = true, if animation shall be enabled | Scalar | true |
mo_n | n | Axis orthogonal to unconstrained plane, resolved in frame_a (= same as in frame_b) | Vector of size 3 | |
mo_n_x | n_x | Vector in direction of x-axis of plane, resolved in frame_a (n_x shall be orthogonal to n) | Vector of size 3 | |
mo_ndim | ndim | Scalar | ||
mo_e | e | Vector of size 3 | ||
mo_s_x | s_x | s_x | Structure | |
mo_s_x/fixed | fixed | Cell of scalars | true | |
mo_s_x/start | start | Cell of scalars | ||
mo_s_y | s_y | s_y | Structure | |
mo_s_y/fixed | fixed | Cell of scalars | true | |
mo_s_y/start | start | Cell of scalars | ||
mo_phi | phi | phi | Structure | |
mo_phi/fixed | fixed | Cell of scalars | true | |
mo_phi/start | start | Cell of scalars | ||
mo_v_x | v_x | v_x | Structure | |
mo_v_x/fixed | fixed | Cell of scalars | true | |
mo_v_x/start | start | Cell of scalars | ||
mo_v_y | v_y | v_y | Structure | |
mo_v_y/fixed | fixed | Cell of scalars | true | |
mo_v_y/start | start | Cell of scalars | ||
mo_w | w | w | Structure | |
mo_w/fixed | fixed | Cell of scalars | true | |
mo_w/start | start | Cell of scalars | ||
mo_a_x | a_x | a_x | Structure | |
mo_a_x/fixed | fixed | Cell of scalars | true | |
mo_a_x/start | start | Cell of scalars | ||
mo_a_y | a_y | a_y | Structure | |
mo_a_y/fixed | fixed | Cell of scalars | true | |
mo_a_y/start | start | Cell of scalars | ||
mo_wd | wd | wd | Structure | |
mo_wd/fixed | fixed | Cell of scalars | true | |
mo_wd/start | start | Cell of scalars |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_cylinderLength | cylinderLength | Length of revolute cylinder | Scalar | |
mo_cylinderDiameter | cylinderDiameter | Diameter of revolute cylinder | Scalar | |
mo_cylinderColor | cylinderColor | Color of revolute cylinder | Vector of size 3 | |
mo_boxWidth | boxWidth | Width of prismatic joint boxes | Scalar | |
mo_boxHeight | boxHeight | Height of prismatic joint boxes | Scalar | |
mo_boxColor | boxColor | Color of prismatic joint boxes | Vector of size 3 |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo_stateSelect | stateSelect | Priority to use joint coordinates (s_x, s_y, phi, v_x, v_y, w) as states | Structure | |
mo_stateSelect/choice1 | StateSelect.never | Number | 0 | |
mo_stateSelect/choice2 | StateSelect.avoid | Number | 0 | |
mo_stateSelect/choice3 | StateSelect.default | Number | 0 | |
mo_stateSelect/choice4 | StateSelect.prefer | Number | 0 | |
mo_stateSelect/choice5 | StateSelect.always | Number | 0 |
| Name | Label | Description | Data Type | Valid Values |
|---|---|---|---|---|
mo__nmodifiers | Number of Modifiers | Specifies the number of modifiers | Number | |
mo__modifiers | Modifiers | Add new modifier | Structure | |
mo__modifiers/varname | Variable name | Cell of strings | ||
mo__modifiers/attribute | Attribute | Cell of strings | 'start' | |
mo__modifiers/value | Value |
Ports
| Name | Type | Description | IO Type | Number |
|---|---|---|---|---|
frame_a | implicit | Coordinate system a fixed to the component with one cut-force and cut-torque | input | 1 |
frame_b | implicit | Coordinate system b fixed to the component with one cut-force and cut-torque | output | 1 |