Description

TMeasy tire model.

The Chrono implementation is a basic version of the commercial models available at www.tmeasy.de.

#include <ChTMeasyTire.h>

Inheritance diagram for chrono::vehicle::ChTMeasyTire:

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Collaboration diagram for chrono::vehicle::ChTMeasyTire:

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Public Member Functions
	ChTMeasyTire (const std::string &name)

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

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.

void	SetGammaLimit (double gamma_limit)
	Set the limit for camber angle (in degrees). Default: 3 degrees.

virtual double	GetWidth () const override
	Get the width of the tire.

virtual double	GetVisualizationWidth () const
	Get visualization width.

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

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

double	GetCamberAngle_internal ()
	Get the camber angle computed internally by the TMeasy model (in radians). More...

void	GuessTruck80Par (unsigned int li, double tireWidth, double ratio, double rimDia, double pinfl_li=1.0, double pinfl_use=1.0, double damping_ratio=0.5)
	Guess Tire Parameters from characteristic truck tire parameter pattern (Ratio = 80%). More...

void	GuessTruck80Par (double loadForce, double tireWidth, double ratio, double rimDia, double pinfl_li=1.0, double pinfl_use=1.0, double damping_ratio=0.5)

void	GuessPassCar70Par (unsigned int li, double tireWidth, double ratio, double rimDia, double pinfl_li=1.0, double pinfl_use=1.0, double damping_ratio=0.5)
	Guess Tire Parameters from characteristic passenger car tire parameter pattern (Ratio = 70%). More...

void	GuessPassCar70Par (double loadForce, double tireWidth, double ratio, double rimDia, double pinfl_li=1.0, double pinfl_use=1.0, double damping_ratio=0.5)

void	SetVerticalStiffness (double Cz)
	Set vertical tire stiffness as linear function by coefficient [N/m].

void	SetVerticalStiffness (double Cz1, double Cz2)
	Set vertical tire stiffness as nonlinear function by coefficients at nominal load 1 [N/m] and nominal load 2 [N/m].

void	SetVerticalStiffness (std::vector< double > &defl, std::vector< double > &frc)
	Set vertical tire stiffness as nonlinear function by calculation from tire test data (least squares).

void	SetFrictionCoefficient (double coeff)
	Set the tire reference coefficient of friction.

void	SetRollingResistanceCoefficients (double rr_coeff_1, double rr_coeff_2)
	Set rolling resistance coefficients.

void	SetDynamicRadiusCoefficients (double rdyn_coeff_1, double rdyn_coeff_2)
	Set dynamic radius coefficients.

void	WritePlots (const std::string &plFileName, const std::string &plTireFormat)
	Generate basic tire plots. More...

virtual double	GetDeflection () const override
	Get the tire deflection.

ChVector	GetDeflection3 ()
	Using tire relaxation, we have three tire deflections.

void	ExportParameterFile (std::string fileName)
	Export a TMeasy Tire Parameter File.

void	ExportJSONFile (std::string jsonFileName)
	Export a TMeasy Tire Parameter File in JSON format.

bool	CheckParameters ()
	Simple parameter consistency test.

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...

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.

Static Public Member Functions
static double	GetTireMaxLoad (unsigned int li)
	Get maximum tire load from Load Index (LI) in N [0:279].

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...

Protected Member Functions
virtual void	SetTMeasyParams ()=0
	Set the parameters in the TMeasy model.

virtual double	GetNormalStiffnessForce (double depth) const override final
	Return the vertical tire stiffness contribution to the normal force.

virtual double	GetNormalDampingForce (double depth, double velocity) const override final
	Return the vertical tire damping contribution to the normal force.

double	InterpL (double fz, double w1, double w2)

double	InterpQ (double fz, double w1, double w2)

void	UpdateVerticalStiffness ()

virtual void	Initialize (std::shared_ptr< ChWheel > wheel) override
	Initialize this tire by associating it to the specified wheel.

virtual void	Synchronize (double time, const ChTerrain &terrain) override
	Update the state of this tire system at the current time. More...

virtual void	Advance (double step) override
	Advance the state of this tire by the specified time step.

void	tmxy_combined (double &f, double &fos, double s, double df0, double sm, double fm, double ss, double fs)

double	tmy_tireoff (double sy, double nto0, double synto0, double syntoE)

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

virtual TerrainForce	GetTireForce () const override
	Get the tire force and moment. More...

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...

virtual void	Create (const rapidjson::Document &d)
	Create a vehicle subsystem from JSON data. More...

Protected Attributes
bool	m_consider_relaxation

bool	m_use_Reff_fallback_calculation

bool	m_use_startup_transition

unsigned int	m_integration_method

double	m_time

double	m_begin_start_transition

double	m_end_start_transition

double	m_vnum

double	m_gamma
	actual camber angle

double	m_gamma_limit
	limit camber angle (degrees!)

double	m_unloaded_radius
	reference tire radius

double	m_width
	tire width

double	m_rim_radius
	tire rim radius

double	m_roundness
	roundness factor for cross-section profile

double	m_rolling_resistance
	actual rolling friction coeff

double	m_mu
	local friction coefficient of the road

double	m_a1
	polynomial coefficient a1 in cz = a1 + 2.0a2 deflection

double	m_a2
	polynomial coefficient a2 in cz = a1 + 2.0a2 deflection

double	m_tau_x
	Longitudinal relaxation delay time.

double	m_tau_y
	Lateral relaxation delay time.

double	m_relaxation_lenght_x
	Longitudinal relaxation length.

double	m_relaxation_lenght_y
	Lateral relaxation length.

double	m_relaxation_lenght_phi
	Relaxation length for bore movement.

double	m_rdynco
	actual value of dynamic rolling radius weighting coefficient

double	m_rdynco_crit
	max. considered value of m_rdynco (local minimum of dynamic rolling radius)

double	m_fz_rdynco_crit
	Fz value r_dyn = r_dyn(m_fz_rdynco,m_rdynco_crit)

VehicleSide	m_measured_side

TMeasyCoeff	m_TMeasyCoeff

std::vector< double >	m_tire_test_defl

std::vector< double >	m_tire_test_frc

TireStates	m_states

std::shared_ptr< ChCylinderShape >	m_cyl_shape
	visualization cylinder asset

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 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).

Member Function Documentation

◆ GetCamberAngle_internal()

double chrono::vehicle::ChTMeasyTire::GetCamberAngle_internal ( )

inline

Get the camber angle computed internally by the TMeasy model (in radians).

The reported value will be similar to that reported by ChTire::GetCamberAngle.

◆ GetLongitudinalSlip_internal()

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

inline

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

The reported value will be similar to that reported by ChTire::GetLongitudinalSlip.

◆ GetSlipAngle_internal()

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

inline

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

The reported value will be similar to that reported by ChTire::GetSlipAngle.

◆ GuessPassCar70Par() [1/2]

void chrono::vehicle::ChTMeasyTire::GuessPassCar70Par	(	double	loadForce,
		double	tireWidth,
		double	ratio,
		double	rimDia,
		double	pinfl_li = `1.0`,
		double	pinfl_use = `1.0`,
		double	damping_ratio = `0.5`
	)

Parameters

loadForce	tire nominal load force [N]
tireWidth	tire width [m]
ratio	use 0.75 meaning 75%
rimDia	rim diameter [m]
pinfl_li	inflation pressure at load index
pinfl_use	inflation pressure in this configuration
damping_ratio	scaling factor for normal damping coefficient

◆ GuessPassCar70Par() [2/2]

void chrono::vehicle::ChTMeasyTire::GuessPassCar70Par	(	unsigned int	li,
		double	tireWidth,
		double	ratio,
		double	rimDia,
		double	pinfl_li = `1.0`,
		double	pinfl_use = `1.0`,
		double	damping_ratio = `0.5`
	)

Guess Tire Parameters from characteristic passenger car tire parameter pattern (Ratio = 70%).

Parameters

li	tire load index
tireWidth	tire width [m]
ratio	use 0.75 meaning 75%
rimDia	rim diameter [m]
pinfl_li	inflation pressure at load index
pinfl_use	inflation pressure in this configuration
damping_ratio	scaling factor for normal damping coefficient

◆ GuessTruck80Par() [1/2]

void chrono::vehicle::ChTMeasyTire::GuessTruck80Par	(	double	loadForce,
		double	tireWidth,
		double	ratio,
		double	rimDia,
		double	pinfl_li = `1.0`,
		double	pinfl_use = `1.0`,
		double	damping_ratio = `0.5`
	)

Parameters

loadForce	tire nominal load force [N]
tireWidth	tire width [m]
ratio	use 0.75 meaning 75%
rimDia	rim diameter [m]
pinfl_li	inflation pressure at load index
pinfl_use	inflation pressure in this configuration
damping_ratio	scaling factor for normal damping coefficient

◆ GuessTruck80Par() [2/2]

void chrono::vehicle::ChTMeasyTire::GuessTruck80Par	(	unsigned int	li,
		double	tireWidth,
		double	ratio,
		double	rimDia,
		double	pinfl_li = `1.0`,
		double	pinfl_use = `1.0`,
		double	damping_ratio = `0.5`
	)

Guess Tire Parameters from characteristic truck tire parameter pattern (Ratio = 80%).

Parameters

li	tire load index
tireWidth	tire width [m]
ratio	use 0.75 meaning 75%
rimDia	rim diameter [m]
pinfl_li	inflation pressure at load index
pinfl_use	inflation pressure in this configuration
damping_ratio	scaling factor for normal damping coefficient

◆ Synchronize()

void chrono::vehicle::ChTMeasyTire::Synchronize	(	double	time,
		const ChTerrain &	terrain
	)

overrideprotectedvirtual

Update the state of this tire system at the current time.

Parameters

[in]	time	current time
[in]	terrain	reference to the terrain system

Reimplemented from chrono::vehicle::ChTire.

◆ WritePlots()

void chrono::vehicle::ChTMeasyTire::WritePlots	(	const std::string &	plFileName,
		const std::string &	plTireFormat
	)

Generate basic tire plots.

This function creates a Gnuplot script file with the specified name.

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

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

Description

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Member Function Documentation

◆ GetCamberAngle_internal()

◆ GetLongitudinalSlip_internal()

◆ GetSlipAngle_internal()

◆ GuessPassCar70Par() [1/2]

◆ GuessPassCar70Par() [2/2]

◆ GuessTruck80Par() [1/2]

◆ GuessTruck80Par() [2/2]

◆ Synchronize()

◆ WritePlots()