Description

Base class for a vehicle wheel subsystem.

A wheel subsystem does not own a body. Instead, when attached to a suspension subsystem, the wheel's mass properties are used to update those of the spindle body owned by the suspension. A concrete wheel subsystem can optionally carry its own visualization assets (which are associated with the suspension's spindle body).

#include <ChWheel.h>

Inheritance diagram for chrono::vehicle::ChWheel:
Collaboration diagram for chrono::vehicle::ChWheel:

Public Member Functions

 ChWheel (const std::string &name)
 
virtual std::string GetTemplateName () const override
 Get the name of the vehicle subsystem template.
 
virtual double GetMass () const =0
 Get the wheel mass.
 
virtual ChVector GetInertia () const =0
 Get the wheel moments of inertia.
 
virtual double GetRadius () const
 Get the wheel radius (for visualization only).
 
virtual double GetWidth () const
 Get the wheel width (for visualization only).
 
virtual void Initialize (std::shared_ptr< ChBody > spindle, VehicleSide side, double offset=0)
 Initialize this wheel subsystem by associating it to an existing spindle of a suspension subsystem. More...
 
void Synchronize ()
 Synchronize the wheel subsystem. More...
 
std::shared_ptr< ChTireGetTire () const
 Get the tire attached to this wheel.
 
void SetTire (std::shared_ptr< ChTire > tire)
 Associate the given tire with this wheel.
 
std::shared_ptr< ChBodyGetSpindle () const
 Get the associated spindle body.
 
VehicleSide GetSide () const
 Get the vehicle side on which this wheel is mounted.
 
ChVector GetPos () const
 Get wheel position (expressed in absolute frame).
 
WheelState GetState () const
 Get the current state for this wheel. More...
 
virtual void AddVisualizationAssets (VisualizationType vis) override
 Add visualization assets for the wheel subsystem. More...
 
virtual void RemoveVisualizationAssets () override
 Remove visualization assets for the wheel subsystem.
 
- Public Member Functions inherited from chrono::vehicle::ChPart
 ChPart (const std::string &name)
 Construct a vehicle subsystem with the specified name. More...
 
const std::string & GetName () const
 Get the name identifier for this subsystem.
 
void SetName (const std::string &name)
 Set the name identifier for this subsystem.
 
void SetVisualizationType (VisualizationType vis)
 Set the visualization mode for this subsystem.
 
void SetContactFrictionCoefficient (float friction_coefficient)
 Set coefficient of friction. More...
 
void SetContactRestitutionCoefficient (float restitution_coefficient)
 Set coefficient of restitution. More...
 
void SetContactMaterialProperties (float young_modulus, float poisson_ratio)
 Set contact material properties. More...
 
void SetContactMaterialCoefficients (float kn, float gn, float kt, float gt)
 Set contact material coefficients. More...
 
float GetCoefficientFriction () const
 Get coefficient of friction for contact material.
 
float GetCoefficientRestitution () const
 Get coefficient of restitution for contact material.
 
float GetYoungModulus () const
 Get Young's modulus of elasticity for contact material.
 
float GetPoissonRatio () const
 Get Poisson ratio for contact material.
 
float GetKn () const
 Get normal stiffness coefficient for contact material.
 
float GetKt () const
 Get tangential stiffness coefficient for contact material.
 
float GetGn () const
 Get normal viscous damping coefficient for contact material.
 
float GetGt () const
 Get tangential viscous damping coefficient for contact material.
 
virtual void SetOutput (bool state)
 Enable/disable output for this subsystem.
 
bool OutputEnabled () const
 Return the output state for this subsystem.
 
virtual void ExportComponentList (rapidjson::Document &jsonDocument) const
 Export this subsystem's component list to the specified JSON object. More...
 
virtual void Output (ChVehicleOutput &database) const
 Output data for this subsystem's component list to the specified database.
 

Protected Attributes

std::shared_ptr< ChBodym_spindle
 associated suspension spindle body
 
std::shared_ptr< ChTirem_tire
 attached tire subsystem
 
VehicleSide m_side
 wheel mounted on left/right side
 
double m_offset
 offset from spindle center
 
std::shared_ptr< ChCylinderShapem_cyl_shape
 visualization cylinder asset
 
- Protected Attributes inherited from chrono::vehicle::ChPart
std::string m_name
 subsystem name
 
bool m_output
 specifies whether or not output is generated for this subsystem
 
float m_friction
 contact coefficient of friction
 
float m_restitution
 contact coefficient of restitution
 
float m_young_modulus
 contact material Young modulus
 
float m_poisson_ratio
 contact material Poisson ratio
 
float m_kn
 normal contact stiffness
 
float m_gn
 normal contact damping
 
float m_kt
 tangential contact stiffness
 
float m_gt
 tangential contact damping
 

Friends

class ChTire
 
class ChWheeledVehicle
 

Additional Inherited Members

- Static Public Member Functions inherited from chrono::vehicle::ChPart
static ChMatrix33 TransformInertiaMatrix (const ChVector<> &moments, const ChVector<> &products, const ChMatrix33<> &vehicle_rot, const ChMatrix33<> &body_rot)
 Utility function for transforming inertia tensors between centroidal frames. More...
 
- Protected Member Functions inherited from chrono::vehicle::ChPart
virtual void Create (const rapidjson::Document &d)
 Create a vehicle subsystem from JSON data. More...
 
- Static Protected Member Functions inherited from chrono::vehicle::ChPart
static void ExportBodyList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChBody >> bodies)
 Export the list of bodies to the specified JSON document.
 
static void ExportShaftList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaft >> shafts)
 Export the list of shafts to the specified JSON document.
 
static void ExportJointList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLink >> joints)
 Export the list of joints to the specified JSON document.
 
static void ExportCouplesList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaftsCouple >> couples)
 Export the list of shaft couples to the specified JSON document.
 
static void ExportMarkerList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChMarker >> markers)
 Export the list of markers to the specified JSON document.
 
static void ExportLinSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkSpringCB >> springs)
 Export the list of translational springs to the specified JSON document.
 
static void ExportRotSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkRotSpringCB >> springs)
 Export the list of rotational springs to the specified JSON document.
 
static void ExportBodyLoadList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLoadBodyBody >> loads)
 Export the list of body-body loads to the specified JSON document.
 

Constructor & Destructor Documentation

chrono::vehicle::ChWheel::ChWheel ( const std::string &  name)
Parameters
[in]namename of the subsystem

Member Function Documentation

void chrono::vehicle::ChWheel::AddVisualizationAssets ( VisualizationType  vis)
overridevirtual

Add visualization assets for the wheel subsystem.

This default implementation uses primitives.

Reimplemented from chrono::vehicle::ChPart.

Reimplemented in chrono::vehicle::Wheel, chrono::vehicle::citybus::CityBus_Wheel, chrono::vehicle::hmmwv::HMMWV_Wheel, chrono::vehicle::sedan::Sedan_Wheel, and chrono::vehicle::uaz::UAZBUS_Wheel.

WheelState chrono::vehicle::ChWheel::GetState ( ) const

Get the current state for this wheel.

This includes the location, orientation, linear and angular velocities, all expressed in the global reference frame, as well as the wheel angular speed about its rotation axis.

void chrono::vehicle::ChWheel::Initialize ( std::shared_ptr< ChBody spindle,
VehicleSide  side,
double  offset = 0 
)
virtual

Initialize this wheel subsystem by associating it to an existing spindle of a suspension subsystem.

The optional 'offset' argument allows models with double wheels(tires). The default value offset=0 corresponds to an axle with a single tire. A positive offset corresponds to an "outer" wheel, while a negative offset corresponds to an "inner" wheel. The wheel mass and inertia are used to increment those of the associated spindle body.

Parameters
spindleassociated suspension spindle body
sidewheel mounted on left/right side
offsetoffset from associated spindle center
void chrono::vehicle::ChWheel::Synchronize ( )

Synchronize the wheel subsystem.

This queries the forces from the attached tire and passes it to the associated suspension.