chrono::vehicle::ChWheel Class Reference

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
virtual std::string	GetTemplateName () const override
	Get the name of the vehicle subsystem template.
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< ChChassis > chassis, 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	EnableCollision (bool state)
	Enable/disable contact for the wheel. More...
void	Synchronize ()
	Synchronize the wheel subsystem. More...
void	Synchronize (const TerrainForce &tire_force)
	Synchronize the wheel subsystem. More...
std::shared_ptr< ChTire >	GetTire () 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< ChBody >	GetSpindle () const
	Get the associated spindle body.
VehicleSide	GetSide () const
	Get the vehicle side on which this wheel is mounted.
ChVector3d	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.
const std::string &	GetMeshFilename () const
	Get the name of the Wavefront file with wheel visualization mesh. More...
Public Member Functions inherited from chrono::vehicle::ChPart
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.
bool	IsInitialized () const
	Return flag indicating whether or not the part is fully constructed.
double	GetMass () const
	Get the subsystem mass. More...
const ChFrame &	GetCOMFrame () const
	Get the current subsystem COM frame (relative to and expressed in the subsystem's reference frame). More...
const ChMatrix33 &	GetInertia () const
	Get the current subsystem inertia (relative to the subsystem COM frame). More...
const ChFrame &	GetTransform () const
	Get the current subsystem position relative to the global frame. More...
void	SetVisualizationType (VisualizationType vis)
	Set the visualization mode for this subsystem.
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 Member Functions
	ChWheel (const std::string &name)
	Construct a wheel subsystem with given name.
virtual void	InitializeInertiaProperties () override
	Initialize subsystem inertia properties. More...
virtual void	UpdateInertiaProperties () override
	Update subsystem inertia properties. More...
virtual double	GetWheelMass () const =0
virtual const ChVector3d &	GetWheelInertia () const =0
Protected Member Functions inherited from chrono::vehicle::ChPart
	ChPart (const std::string &name)
	Construct a vehicle subsystem with the specified name.
void	AddMass (double &mass)
	Add this subsystem's mass. More...
void	AddInertiaProperties (ChVector3d &com, ChMatrix33<> &inertia)
	Add this subsystem's inertia properties. More...
virtual void	Create (const rapidjson::Document &d)
	Create a vehicle subsystem from JSON data. More...
void	ExportBodyList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChBody >> bodies) const
	Export the list of bodies to the specified JSON document.
void	ExportShaftList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaft >> shafts) const
	Export the list of shafts to the specified JSON document.
void	ExportJointList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLink >> joints) const
	Export the list of joints to the specified JSON document.
void	ExportCouplesList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaftsCouple >> couples) const
	Export the list of shaft couples to the specified JSON document.
void	ExportMarkerList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChMarker >> markers) const
	Export the list of markers to the specified JSON document.
void	ExportLinSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkTSDA >> springs) const
	Export the list of translational springs to the specified JSON document.
void	ExportRotSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkRSDA >> springs) const
	Export the list of rotational springs to the specified JSON document.
void	ExportBodyLoadList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLoadBodyBody >> loads) const
	Export the list of body-body loads to the specified JSON document.

Protected Attributes
std::shared_ptr< ChBody >	m_spindle
	associated suspension spindle body
std::shared_ptr< ChTire >	m_tire
	attached tire subsystem
VehicleSide	m_side
	wheel mounted on left/right side
double	m_offset
	offset from spindle center
std::string	m_vis_mesh_file
	visualization mesh file (may be empty)
std::shared_ptr< ChVisualShapeTriangleMesh >	m_trimesh_shape
	visualization mesh asset
std::shared_ptr< ChVisualShape >	m_cyl_shape
	visualization cylinder asset
std::shared_ptr< ChLoadBodyForce >	m_spindle_terrain_force
	terrain force loads on the spindle
std::shared_ptr< ChLoadBodyTorque >	m_spindle_terrain_torque
	terrain torque loads on the spindle
Protected Attributes inherited from chrono::vehicle::ChPart
std::string	m_name
	subsystem name
bool	m_initialized
	specifies whether ot not the part is fully constructed
bool	m_output
	specifies whether or not output is generated for this subsystem
std::shared_ptr< ChPart >	m_parent
	parent subsystem (empty if parent is vehicle)
double	m_mass
	subsystem mass
ChMatrix33	m_inertia
	inertia tensor (relative to subsystem COM)
ChFrame	m_com
	COM frame (relative to subsystem reference frame)
ChFrame	m_xform
	subsystem frame expressed in the global frame

Friends
class	ChTire
class	ChWheeledVehicle
class	ChTireTestRig

Additional Inherited Members
Static Public Member Functions inherited from chrono::vehicle::ChPart
static ChMatrix33	TransformInertiaMatrix (const ChVector3d &moments, const ChVector3d &products, const ChMatrix33<> &vehicle_rot, const ChMatrix33<> &body_rot)
	Utility function for transforming inertia tensors between centroidal frames. More...
Static Protected Member Functions inherited from chrono::vehicle::ChPart
static void	RemoveVisualizationAssets (std::shared_ptr< ChPhysicsItem > item)
	Erase all visual shapes from the visual model associated with the specified physics item (if any).
static void	RemoveVisualizationAsset (std::shared_ptr< ChPhysicsItem > item, std::shared_ptr< ChVisualShape > shape)
	Erase the given shape from the visual model associated with the specified physics item (if any).

Member Function Documentation

AddVisualizationAssets()

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::artcar::ARTcar_Wheel.

EnableCollision()

void chrono::vehicle::ChWheel::EnableCollision ( bool  state )

inline

Enable/disable contact for the wheel.

This function controls contact of the wheel with all other collision shapes in the simulation. Must be called after initialization and has effect only if the derived object has defined some collision shapes.

GetMeshFilename()

const std::string& chrono::vehicle::ChWheel::GetMeshFilename ( ) const

inline

Get the name of the Wavefront file with wheel visualization mesh.

An empty string is returned if no mesh was specified.

GetState()

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.

Initialize()

void chrono::vehicle::ChWheel::Initialize ( std::shared_ptr< ChChassis >  chassis, 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

chassis	chassis vehicle (may be null)
spindle	associated suspension spindle body
side	wheel mounted on left/right side
offset	offset from associated spindle center

Reimplemented in chrono::vehicle::jeep::Cherokee_Wheel, chrono::vehicle::hmmwv::HMMWV_Wheel, and chrono::vehicle::generic::Generic_Wheel.

InitializeInertiaProperties()

void chrono::vehicle::ChWheel::InitializeInertiaProperties ( )

overrideprotectedvirtual

Initialize subsystem inertia properties.

Derived classes must override this function and set the subsystem mass (m_mass) and, if constant, the subsystem COM frame and its inertia tensor. This function is called during initialization of the vehicle system.

Implements chrono::vehicle::ChPart.

Synchronize() [1/2]

void chrono::vehicle::ChWheel::Synchronize

(

)

Synchronize the wheel subsystem.

This version queries the forces from the attached tire and applies them to the associated suspension.

Synchronize() [2/2]

void chrono::vehicle::ChWheel::Synchronize

(

const TerrainForce &

tire_force

)

Synchronize the wheel subsystem.

This version uses the provided forces as external applied tire/terrain forces.

UpdateInertiaProperties()

void chrono::vehicle::ChWheel::UpdateInertiaProperties ( )

overrideprotectedvirtual

Update subsystem inertia properties.

Derived classes must override this function and set the global subsystem transform (m_xform) and, unless constant, the subsystem COM frame (m_com) and its inertia tensor (m_inertia). Calculate the current inertia properties and global frame of this subsystem. This function is called every time the state of the vehicle system is advanced in time.

Implements chrono::vehicle::ChPart.

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The documentation for this class was generated from the following files:

• /builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/ChWheel.h
• /builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/ChWheel.cpp