RollingWheel

Joint (no mass, no inertia) that describes an ideal rolling wheel (rolling on the plane z=0)

    RollingWheel

Library

Mechanics/MultiBody/Joints

Description

A joint for a wheel rolling on the x-y plane of the world frame. The rolling contact is considered being ideal, i.e. there is no slip between the wheel and the ground. This is simply gained by two non-holonomic constraint equations on velocity level defined for both longitudinal and lateral direction of the wheel. There is also a holonomic constraint equation on position level granting a permanent contact of the wheel to the ground, i.e. the wheel can not take off.

The origin of the frame frame_a is placed in the intersection of the wheel spin axis with the wheel middle plane and rotates with the wheel itself. The y-axis of frame_a is identical with the wheel spin axis, i.e. the wheel rotates about y-axis of frame_a. A wheel body collecting the mass and inertia should be connected to this frame.

Note

To work properly, the gravity acceleration vector g of the world must point in the negative z-axis, i.e.

inner Modelica.Mechanics.MultiBody.World world(n={0,0,-1});

Parameters

RollingWheel_0

NameLabelDescriptionData TypeValid Values

mo_wheelRadius

wheelRadius

Wheel radius

Scalar

mo_stateSelect

stateSelect

Priority to use generalized coordinates 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

RollingWheel_1

NameLabelDescriptionData TypeValid Values

mo_x

x

x

Structure

mo_x/fixed

fixed

Cell of scalars

true
false

mo_x/start

start

Cell of scalars

mo_y

y

y

Structure

mo_y/fixed

fixed

Cell of scalars

true
false

mo_y/start

start

Cell of scalars

mo_z

z

z

Structure

mo_z/fixed

fixed

Cell of scalars

true
false

mo_z/start

start

Cell of scalars

mo_angles

angles

angles

Structure

mo_angles/fixed

fixed

Cell of vectors of size 3

true
false

mo_angles/start

start

Cell of vectors of size 3

mo_der_angles

der_angles

der_angles

Structure

mo_der_angles/fixed

fixed

Cell of vectors of size 3

true
false

mo_der_angles/start

start

Cell of vectors of size 3

mo_r_road_0

r_road_0

r_road_0

Structure

mo_r_road_0/fixed

fixed

Cell of vectors of size 3

true
false

mo_r_road_0/start

start

Cell of vectors of size 3

mo_f_wheel_0

f_wheel_0

f_wheel_0

Structure

mo_f_wheel_0/fixed

fixed

Cell of vectors of size 3

true
false

mo_f_wheel_0/start

start

Cell of vectors of size 3

mo_f_n

f_n

f_n

Structure

mo_f_n/fixed

fixed

Cell of scalars

true
false

mo_f_n/start

start

Cell of scalars

mo_f_lat

f_lat

f_lat

Structure

mo_f_lat/fixed

fixed

Cell of scalars

true
false

mo_f_lat/start

start

Cell of scalars

mo_f_long

f_long

f_long

Structure

mo_f_long/fixed

fixed

Cell of scalars

true
false

mo_f_long/start

start

Cell of scalars

mo_err

err

err

Structure

mo_err/fixed

fixed

Cell of scalars

true
false

mo_err/start

start

Cell of scalars

Ports

NameTypeDescriptionIO TypeNumber

frame_a

implicit

Frame fixed in wheel center point. x-Axis: upwards, y-axis: along wheel axis

input

1