Description

Concrete tire class that implements the Pacejka tire model.

#include <ChPacejkaTire.h>

Inheritance diagram for chrono::vehicle::ChPacejkaTire:

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Collaboration diagram for chrono::vehicle::ChPacejkaTire:

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Public Member Functions
	ChPacejkaTire (const std::string &name, const std::string &pacTire_paramFile)
	Default constructor for a Pacejka tire. More...

	ChPacejkaTire (const std::string &name, const std::string &pacTire_paramFile, double Fz_override, bool use_transient_slip=true)
	Construct a Pacejka tire with specified vertical load, for testing purposes. More...

virtual std::string	GetTemplateName () const override
	Get the name of the vehicle subsystem template.

void	SetDrivenWheel (bool val)
	Specify whether or not the associated wheel is driven. More...

virtual void	AddVisualizationAssets (VisualizationType vis) override
	Add visualization assets for the rigid tire subsystem.

virtual void	RemoveVisualizationAssets () override
	Remove visualization assets for the rigid tire subsystem.

virtual double	GetRadius () const override
	Get the tire radius.

virtual double	GetWidth () const override
	Get tire width.

virtual double	GetVisualizationWidth () const
	Get visualization tire width.

TerrainForce	GetTireForce_pureSlip (const bool local=true) const
	Return the reactions for the pure slip EQs, in local or global coords.

TerrainForce	GetTireForce_combinedSlip (const bool local=true) const
	Return the reactions for the combined slip EQs, in local or global coords. More...

double	GetSlipAngle_internal () const
	Get the tire slip angle computed internally by the Pacejka model (in radians). More...

double	GetLongitudinalSlip_internal () const
	Get the tire longitudinal slip computed internally by the Pacejka model. More...

double	GetCamberAngle_internal () const
	Get the camber angle for the Pacejka tire model (in radians). More...

void	WriteOutData (double time, const std::string &outFilename)
	Write output data to a file.

void	set_Fz_override (double Fz)
	Manually set the vertical wheel load as an input.

WheelState	getState_from_KAG (double kappa, double alpha, double gamma, double Vx)
	Return orientation, Vx (global) and omega/omega_y (global). More...

double	get_average_Advance_time ()
	Get the average simulation time per step spent in advance()

double	get_average_ODE_time ()
	Get the average simulation time per step spent in calculating ODEs.

double	get_kappa () const
	Get current wheel longitudinal slip.

double	get_alpha () const
	Get current wheel slip angle.

double	get_gamma () const
	Get current wheel camber angle.

double	get_kappaPrime () const
	Get current long slip rate used in Magic Formula EQs.

double	get_alphaPrime () const
	Get current slip angle using in Magic Formula.

double	get_gammaPrime () const
	Get current camber angle used in Magic Formula.

double	get_min_long_slip () const
	Get minimum longitudinal slip rate.

double	get_max_long_slip () const
	Get maximum longitudinal slip rate.

double	get_min_lat_slip () const
	Get the minimum allowable lateral slip angle, alpha.

double	get_max_lat_slip () const
	Get the maximum allowable lateral slip angle, alpha.

double	get_longvl () const
	Get the longitudinal velocity.

double	get_tire_rolling_rad () const
	Get the tire rolling radius, ideally updated each step.

Public Member Functions inherited from chrono::vehicle::ChForceElementTire
virtual TerrainForce	ReportTireForce (ChTerrain *terrain) const override
	Report the tire force and moment.

Public Member Functions inherited from chrono::vehicle::ChTire
void	SetStepsize (double val)
	Set the value of the integration step size for the underlying dynamics (if applicable). More...

double	GetStepsize () const
	Get the current value of the integration step size.

void	SetCollisionType (CollisionType collision_type)
	Set the collision type for tire-terrain interaction. More...

virtual double	GetTireMass () const =0
	Return the tire mass.

virtual ChVector	GetTireInertia () const =0
	Return the tire moments of inertia (in the tire centroidal frame).

double	GetSlipAngle () const
	Return the tire slip angle calculated based on the current state of the associated wheel body. More...

double	GetLongitudinalSlip () const
	Return the tire longitudinal slip calculated based on the current state of the associated wheel body. More...

double	GetCamberAngle () const
	Return the tire camber angle calculated based on the current state of the associated wheel body. More...

virtual double	GetDeflection () const
	Report the tire deflection.

const std::string &	GetMeshFilename () const
	Get the name of the Wavefront file with tire 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.

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
const std::string &	getPacTireParamFile () const

Protected Member Functions inherited from chrono::vehicle::ChForceElementTire
	ChForceElementTire (const std::string &name)
	Construct a tire with the specified name.

Protected Member Functions inherited from chrono::vehicle::ChTire
	ChTire (const std::string &name)
	Construct a tire subsystem with given name.

void	CalculateKinematics (const WheelState &wheel_state, const ChCoordsys<> &tire_frame)
	Calculate kinematics quantities based on the given state of the associated wheel body. More...

double	GetOffset () const
	Get offset from spindle center. More...

std::shared_ptr< ChTriangleMeshShape >	AddVisualizationMesh (const std::string &mesh_file_left, const std::string &mesh_file_right)
	Add mesh visualization to the body associated with this tire (a wheel spindle body). More...

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 (ChVector<> &com, ChMatrix33<> &inertia)
	Add this subsystem's inertia properties. More...

Protected Attributes
std::string	m_paramFile

Protected Attributes inherited from chrono::vehicle::ChForceElementTire
ContactData	m_data
	tire-terrain collision information

TerrainForce	m_tireforce
	tire forces (in tire contact frame)

ChFunction_Recorder	m_areaDep

Protected Attributes inherited from chrono::vehicle::ChTire
std::shared_ptr< ChWheel >	m_wheel
	associated wheel subsystem

double	m_stepsize
	tire integration step size (if applicable)

CollisionType	m_collision_type
	method used for tire-terrain collision

std::string	m_vis_mesh_file
	name of OBJ file for visualization of this tire (may be empty)

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

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

Additional Inherited Members
Public Types inherited from chrono::vehicle::ChTire
enum	CollisionType { SINGLE_POINT, FOUR_POINTS, ENVELOPE }

Static Public Member Functions inherited from chrono::vehicle::ChTire
static ChVector	EstimateInertia (double tire_width, double aspect_ratio, double rim_diameter, double tire_mass, double t_factor=2)
	Utility function for estimating the tire moments of inertia. More...

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...

Static Protected Member Functions inherited from chrono::vehicle::ChTire
static bool	DiscTerrainCollision (CollisionType method, const ChTerrain &terrain, const ChVector<> &disc_center, const ChVector<> &disc_normal, double disc_radius, double width, const ChFunction_Recorder &areaDep, ChCoordsys<> &contact, double &depth, float &mu)
	Perform disc-terrain collision detection, using the specified method. More...

static void	ConstructAreaDepthTable (double disc_radius, ChFunction_Recorder &areaDep)
	Utility function to construct a loopkup table for penetration depth as function of intersection area, for a given tire radius. 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< ChLinkTSDA >> springs)
	Export the list of translational springs to the specified JSON document.

static void	ExportRotSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkRSDA >> 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.

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).

Constructor & Destructor Documentation

◆ ChPacejkaTire() [1/2]

chrono::vehicle::ChPacejkaTire::ChPacejkaTire	(	const std::string &	name,
		const std::string &	pacTire_paramFile
	)

Default constructor for a Pacejka tire.

Construct a Pacejka tire for which the vertical load is calculated internally. The model includes transient slip calculations. chrono can suggest a time step for use with the ODE slips

Parameters

[in]	name	name of this tire
[in]	pacTire_paramFile	name of the parameter file

◆ ChPacejkaTire() [2/2]

chrono::vehicle::ChPacejkaTire::ChPacejkaTire	(	const std::string &	name,
		const std::string &	pacTire_paramFile,
		double	Fz_override,
		bool	use_transient_slip = `true`
	)

Construct a Pacejka tire with specified vertical load, for testing purposes.

Parameters

[in]	name	name of this tire
[in]	pacTire_paramFile	name of the parameter file
[in]	Fz_override	prescribed vertical load
[in]	use_transient_slip	indicate if using transient slip model

Member Function Documentation

◆ GetCamberAngle_internal()

double chrono::vehicle::ChPacejkaTire::GetCamberAngle_internal ( ) const

inline

Get the camber angle for the Pacejka tire model (in radians).

The reported value will be the same as that reported by ChTire::GetCamberAngle.

◆ GetLongitudinalSlip_internal()

double chrono::vehicle::ChPacejkaTire::GetLongitudinalSlip_internal ( ) const

inline

Get the tire longitudinal slip computed internally by the Pacejka model.

The reported value will be the same as that reported by ChTire::GetLongitudinalSlip.

◆ GetSlipAngle_internal()

double chrono::vehicle::ChPacejkaTire::GetSlipAngle_internal ( ) const

inline

Get the tire slip angle computed internally by the Pacejka model (in radians).

The reported value will be the same as that reported by ChTire::GetSlipAngle.

◆ getState_from_KAG()

WheelState chrono::vehicle::ChPacejkaTire::getState_from_KAG	(	double	kappa,
		double	alpha,
		double	gamma,
		double	Vx
	)

Return orientation, Vx (global) and omega/omega_y (global).

Assumes the tire is going straight forward (global x-dir), and the returned state's orientation yields gamma and alpha, as x and z NASA angles

Parameters

[in]	kappa	...
[in]	alpha	...
[in]	gamma	...
[in]	Vx	tire forward velocity x-dir

◆ GetTireForce_combinedSlip()

TerrainForce chrono::vehicle::ChPacejkaTire::GetTireForce_combinedSlip ( const bool local = true ) const

Return the reactions for the combined slip EQs, in local or global coords.

Return the reactions for the combined slip EQs, in local or global coordinates.

◆ SetDrivenWheel()

void chrono::vehicle::ChPacejkaTire::SetDrivenWheel ( bool val )

inline

Specify whether or not the associated wheel is driven.

By default, the wheel is assumed not driven.

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

/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/tire/ChPacejkaTire.h
/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/tire/ChPacejkaTire.cpp

Description

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ ChPacejkaTire() [1/2]

◆ ChPacejkaTire() [2/2]

Member Function Documentation

◆ GetCamberAngle_internal()

◆ GetLongitudinalSlip_internal()

◆ GetSlipAngle_internal()

◆ getState_from_KAG()

◆ GetTireForce_combinedSlip()

◆ SetDrivenWheel()