Description

Base class for a Rack-Pinion steering subsystem.

Derived from ChSteering, but still an abstract base class.

The steering subsystem is modeled with respect to a right-handed frame with with X pointing towards the front, Y to the left, and Z up (ISO standard). The steering link translates along the Y axis. We do not explicitly model the pinion but instead use the implied rack-pinion constraint to calculate the rack displacement from a given pinion rotation angle.

#include <ChRackPinion.h>

Inheritance diagram for chrono::vehicle::ChRackPinion:

[legend]

Collaboration diagram for chrono::vehicle::ChRackPinion:

[legend]

Public Member Functions
	ChRackPinion (const std::string &name)
	Construct a rack-pinion steering mechanism with given base name. More...

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

virtual void	Initialize (std::shared_ptr< ChBodyAuxRef > chassis, const ChVector<> &location, const ChQuaternion<> &rotation) override
	Initialize the steering subsystem. More...

virtual void	AddVisualizationAssets (VisualizationType vis) override
	Add visualization assets for the steering subsystem. More...

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

virtual void	Synchronize (double time, double steering) override
	Update the state of this steering subsystem at the current time. More...

virtual double	GetMass () const override
	Get the total mass of the steering subsystem.

virtual ChVector	GetCOMPos () const override
	Get the current global COM location of the steering subsystem.

virtual void	LogConstraintViolations () override
	Log current constraint violations.

Public Member Functions inherited from chrono::vehicle::ChSteering
	ChSteering (const std::string &name)

const ChCoordsys &	GetPosition () const
	Get the position (location and orientation) of the steering subsystem relative to the chassis reference frame.

std::shared_ptr< ChBody >	GetSteeringLink () const
	Get a handle to the main link of the steering subsystems. More...

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.

Protected Member Functions
virtual double	GetSteeringLinkMass () const =0
	Return the mass of the steering link.

virtual ChVector	GetSteeringLinkInertia () const =0
	Return the moments of inertia of the steering link.

virtual double	GetSteeringLinkCOM () const =0
	Return the steering link COM offset in Y direction (positive to the left).

virtual double	GetSteeringLinkRadius () const =0
	Return the radius of the steering link (visualization only).

virtual double	GetSteeringLinkLength () const =0
	Return the length of the steering link (visualization only).

virtual double	GetPinionRadius () const =0
	Return the radius of the pinion.

virtual double	GetMaxAngle () const =0
	Return the maximum rotation angle of the pinion (in either direction).

virtual void	ExportComponentList (rapidjson::Document &jsonDocument) const override
	Export this subsystem's component list to the specified JSON object. More...

virtual void	Output (ChVehicleOutput &database) const override
	Output data for this subsystem's component list to the specified database.

Protected Member Functions inherited from chrono::vehicle::ChPart
virtual void	Create (const rapidjson::Document &d)
	Create a vehicle subsystem from JSON data. More...

Protected Attributes
std::shared_ptr< ChLinkLockPrismatic >	m_prismatic
	handle to the prismatic joint chassis-link

std::shared_ptr< ChLinkLinActuator >	m_actuator
	handle to the linear actuator on steering link

Protected Attributes inherited from chrono::vehicle::ChSteering
ChCoordsys	m_position
	location and orientation relative to chassis

std::shared_ptr< ChBody >	m_link
	handle to the main steering link

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

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...

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< 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

◆ ChRackPinion()

chrono::vehicle::ChRackPinion::ChRackPinion ( const std::string & name )

Construct a rack-pinion steering mechanism with given base name.

Parameters

[in] name name of the subsystem

Member Function Documentation

◆ AddVisualizationAssets()

void chrono::vehicle::ChRackPinion::AddVisualizationAssets ( VisualizationType vis )

overridevirtual

Add visualization assets for the steering subsystem.

This default implementation uses primitives.

Reimplemented from chrono::vehicle::ChPart.

◆ ExportComponentList()

void chrono::vehicle::ChRackPinion::ExportComponentList ( rapidjson::Document & jsonDocument ) const

overrideprotectedvirtual

Export this subsystem's component list to the specified JSON object.

Derived classes should override this function and first invoke the base class implementation, followed by calls to the various static Export***List functions, as appropriate.

Reimplemented from chrono::vehicle::ChPart.

◆ Initialize()

void chrono::vehicle::ChRackPinion::Initialize	(	std::shared_ptr< ChBodyAuxRef >	chassis,
		const ChVector<> &	location,
		const ChQuaternion<> &	rotation
	)

overridevirtual

Initialize the steering subsystem.

This attached the steering mechanism to the specified chassis body at the given offset and orientation, relative to the frame of the chassis.

Parameters

	chassis	pin] handle to the chassis body
[in]	location	location relative to the chassis frame
[in]	rotation	orientation relative to the chassis frame

Implements chrono::vehicle::ChSteering.

◆ Synchronize()

void chrono::vehicle::ChRackPinion::Synchronize	(	double	time,
		double	steering
	)

overridevirtual

Update the state of this steering subsystem at the current time.

The steering subsystem is provided the current steering driver input (a value between -1 and +1). Positive steering input indicates steering to the left. This function is called during the vehicle update.

Parameters

[in]	time	current time
[in]	steering	current steering input [-1,+1]

Implements chrono::vehicle::ChSteering.

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

/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/steering/ChRackPinion.h
/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/steering/ChRackPinion.cpp

Description

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ ChRackPinion()

Member Function Documentation

◆ AddVisualizationAssets()

◆ ExportComponentList()

◆ Initialize()

◆ Synchronize()