Planar

Planar joint (3 degrees-of-freedom, 6 potential states)

    Planar

Library

Mechanics/MultiBody/Joints

Description

Joint where frame_b can move in a plane and can rotate around an axis orthogonal to the plane. The plane is defined by vector 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 following potential 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 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 planar 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 arrows are parameter vectors "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

Planar_0

NameLabelDescriptionData TypeValid Values

mo_animation

animation

= true, if animation shall be enabled

Scalar

true
false

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

Planar_1

NameLabelDescriptionData TypeValid 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

Planar_2

NameLabelDescriptionData TypeValid 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
1

mo_stateSelect/choice2

StateSelect.avoid

Number

0
1

mo_stateSelect/choice3

StateSelect.default

Number

0
1

mo_stateSelect/choice4

StateSelect.prefer

Number

0
1

mo_stateSelect/choice5

StateSelect.always

Number

0
1

Planar_3

NameLabelDescriptionData TypeValid Values

mo_prismatic_x

prismatic_x

prismatic_x

Structure

mo_prismatic_x/fixed

fixed

Cell of scalars

mo_prismatic_y

prismatic_y

prismatic_y

Structure

mo_prismatic_y/fixed

fixed

Cell of scalars

mo_revolute

revolute

revolute

Structure

mo_revolute/fixed

fixed

Cell of scalars

mo_s_x

s_x

s_x

Structure

mo_s_x/fixed

fixed

Cell of scalars

true
false

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
false

mo_s_y/start

start

Cell of scalars

mo_phi

phi

phi

Structure

mo_phi/fixed

fixed

Cell of scalars

true
false

mo_phi/start

start

Cell of scalars

mo_v_x

v_x

v_x

Structure

mo_v_x/fixed

fixed

Cell of scalars

true
false

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
false

mo_v_y/start

start

Cell of scalars

mo_w

w

w

Structure

mo_w/fixed

fixed

Cell of scalars

true
false

mo_w/start

start

Cell of scalars

mo_a_x

a_x

a_x

Structure

mo_a_x/fixed

fixed

Cell of scalars

true
false

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
false

mo_a_y/start

start

Cell of scalars

mo_wd

wd

wd

Structure

mo_wd/fixed

fixed

Cell of scalars

true
false

mo_wd/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

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