WOLFRAM SYSTEMMODELER

SlipBasedWheelJoint

Slip-Friction based wheel joint

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 rupper 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 by 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 (18)

useHeatPort

Value: false

Type: Boolean

Description: =true, if heatPort is enabled

T

Value: 293.15

Type: Temperature (K)

Description: Fixed device temperature if useHeatPort = false

stateSelect

Value: StateSelect.default

Type: StateSelect

Description: Priority to use acceleration as states

radius

Value:

Type: Length (m)

Description: Radius of the wheel

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: sqrt(r * r)

Type: Length (m)

Description: Length of vector r

e

Value: r / l

Type: Real[2]

Description: Normalized direction

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)

Connectors (4)

heatPort

Type: HeatPort_a

Description: Optional port to which dissipated losses are transported in form of heat

frame_a

Type: Frame_a

flange_a

Type: Flange_a

dynamicLoad

Type: RealInput

Components (4)

planarWorld

Type: PlanarWorld

Description: planar world model

cylinder

Type: Shape

rim1

Type: Shape

rim2

Type: Shape

Used in Examples (1)

TestSlipBasedWheel

PlanarMechanics.VehicleComponents.Examples

A slip-based wheel