# RollingWheel

Ideal rolling wheel on flat surface z=0 (5 positional, 3 velocity degrees of freedom)

# Information

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

A wheel rolling on the x-y plane of the world frame including wheel mass and simple visualization. The rolling contact is considered being ideal, i.e. there is no slip between the wheel and the ground. The wheel can not take off but it can incline toward the ground. The frame frame_a is placed in the wheel center point and rotates with the wheel itself. Therefore, a rotational joint with rotation axis `n={0,1,0}` should be used to connect the wheel to a carrier.

#### 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 (9)

animation Value: true Type: Boolean Description: = true, if animation of wheel shall be enabled Value: Type: Radius (m) Description: Radius of wheel Value: Type: Mass (kg) Description: Mass of wheel Value: Type: Inertia (kg·m²) Description: Inertia along the wheel axis Value: Type: Inertia (kg·m²) Description: Inertia perpendicular to the wheel axis Value: StateSelect.always Type: StateSelect Description: Priority to use generalized coordinates as states Value: 0.035 Type: Distance (m) Description: Width of wheel Value: 0.8 Type: Real Description: 1.0: Completely hollow, 0.0: rigid cylinder Value: {30, 30, 30} Type: Color Description: Color of wheel

# Connectors (1)

frame_a Type: Frame_a Description: Frame fixed in wheel center point (y-axis: along wheel axis, z-axis: upwards)

# Components (3)

body Type: Body Type: RollingWheel Type: FixedShape

# Used in Examples (1)

 RollingWheel Modelica.Mechanics.MultiBody.Examples.Elementary Single wheel rolling on ground starting from an initial speed