WOLFRAM SYSTEM MODELER
SlipBasedWheelJointSlip-Friction based wheel joint |
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Wolfram Language
In[1]:=
SystemModel["PlanarMechanics.VehicleComponents.Wheels.SlipBasedWheelJoint"]
Out[1]:=
Information
The ideal wheel joint models the behavior of a wheel rolling on a x,y-plane whose contact patch has slip-dependent friction characteristics. This is an approximation for wheels with a rim and a rubber tire.
The force depends with friction characteristics on the slip. The slip is split into two components:
- lateral slip: the lateral velocity divided by the rolling velocity.
- longitudinal slip: the longitudinal slip velocity divided by the rolling velocity.
For low rolling velocity this definitions become ill-conditioned. Hence a dry-friction model is used for low rolling velocities.
The radius of the wheel can be specified by the parameter radius. The driving direction (for phi = 0) can be specified by the parameter r. The normal load is set N.
The wheel contains a 2D connector frame_a for the steering on the plane. The rolling motion of the wheel can be actuated by the 1D connector flange_a.
In addition there is an input for a dynamic component of the normal load.
For examples of usage see the local Examples package.
Parameters (17)
| useHeatPort |
Value: false Type: Boolean Description: = true, if heatPort is enabled |
|---|---|
| radius |
Value: Type: Length (m) Description: Wheel radius |
| stateSelect |
Value: StateSelect.default Type: StateSelect Description: Priority to use acceleration as states |
| r |
Value: Type: Length[2] (m) Description: Driving direction of the wheel at angle phi = 0 |
| N |
Value: Type: Force (N) Description: Base normal load |
| vAdhesion_min |
Value: Type: Velocity (m/s) Description: Minimum adhesion velocity |
| vSlide_min |
Value: Type: Velocity (m/s) Description: Minimum sliding velocity |
| sAdhesion |
Value: Type: Real Description: Adhesion slippage |
| sSlide |
Value: Type: Real Description: Sliding slippage |
| mu_A |
Value: Type: Real Description: Friction coefficient at adhesion |
| mu_S |
Value: Type: Real Description: Friction coefficient at sliding |
| l |
Value: Modelica.Math.Vectors.length(r) Type: Length (m) Description: Length of r |
| e |
Value: Modelica.Math.Vectors.normalizeWithAssert(r) Type: Real[2] Description: Unit vector in direction of r |
| animate |
Value: true Type: Boolean Description: = true, if animation shall be enabled |
| zPosition |
Value: planarWorld.defaultZPosition Type: Length (m) Description: Position z of the body |
| diameter |
Value: 0.1 Type: Length (m) Description: Diameter of the rims |
| width |
Value: diameter * 0.6 Type: Length (m) Description: Width of the wheel |
Inputs (1)
| specularCoefficient |
Default Value: planarWorld.defaultSpecularCoefficient Type: SpecularCoefficient Description: Reflection of ambient light (= 0: light is completely absorbed) |
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Connectors (4)
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heatPort |
Type: HeatPort_a Description: Optional port to which dissipated losses are transported in form of heat |
|---|---|---|
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frame_a |
Type: Frame_a Description: Coordinate system (2-dim.) fixed to the component with one cut-force and cut-torque (blue icon) |
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flange_a |
Type: Flange_a Description: One-dimensional rotational flange of a shaft (filled circle icon) |
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dynamicLoad |
Type: RealInput Description: 'input Real' as connector |
Components (4)
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planarWorld |
Type: PlanarWorld Description: planar world model |
|---|---|---|
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cylinder |
Type: Shape Description: Visualizing an elementary object with variable size; all data have to be set as modifiers (see info layer) |
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rim1 |
Type: Shape Description: Visualizing an elementary object with variable size; all data have to be set as modifiers (see info layer) |
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rim2 |
Type: Shape Description: Visualizing an elementary object with variable size; all data have to be set as modifiers (see info layer) |
Used in Examples (1)
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PlanarMechanics.VehicleComponents.Examples A slip-based wheel |
Revisions
Developed 2010 at the DLR Institute of System Dynamics and Control