Description

Base class for a double-A arm suspension modeled with bodies and constraints.

Derived from ChSuspension, but still an abstract base class.

The suspension subsystem is modeled with respect to a right-handed frame, with X pointing towards the front, Y to the left, and Z up (ISO standard). The suspension reference frame is assumed to be always aligned with that of the vehicle. When attached to a chassis, only an offset is provided.

All point locations are assumed to be given for the left half of the suspension and will be mirrored (reflecting the y coordinates) to construct the right side.

#include <ChDoubleWishbone.h>

Inheritance diagram for chrono::vehicle::ChDoubleWishbone:

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Collaboration diagram for chrono::vehicle::ChDoubleWishbone:

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

virtual bool	IsSteerable () const final override
	Specify whether or not this suspension can be steered.

virtual bool	IsIndependent () const final override
	Specify whether or not this is an independent suspension.

virtual void	Initialize (std::shared_ptr< ChChassis > chassis, std::shared_ptr< ChSubchassis > subchassis, std::shared_ptr< ChSteering > steering, const ChVector3d &location, double left_ang_vel=0, double right_ang_vel=0) override
	Initialize this suspension subsystem. More...

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

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

virtual double	GetTrack () override
	Get the wheel track for the suspension subsystem.

std::shared_ptr< ChLinkTSDA >	GetSpring (VehicleSide side) const
	Get a handle to the specified spring element.

std::shared_ptr< ChLinkTSDA >	GetShock (VehicleSide side) const
	Get a handle to the specified shock (damper) element.

virtual std::vector< ForceTSDA >	ReportSuspensionForce (VehicleSide side) const override
	Return current suspension TSDA force information on the specified side.

double	GetSpringForce (VehicleSide side) const
	Get the force in the spring element.

double	GetSpringLength (VehicleSide side) const
	Get the current length of the spring element.

double	GetSpringDeformation (VehicleSide side) const
	Get the current deformation of the spring element.

double	GetShockForce (VehicleSide side) const
	Get the force in the shock (damper) element.

double	GetShockLength (VehicleSide side) const
	Get the current length of the shock (damper) element.

double	GetShockVelocity (VehicleSide side) const
	Get the current deformation velocity of the shock (damper) element.

ChVector3d	GetBallJointPosLCA (VehicleSide side)
	Get position of the LCA ball joint (expressed in the global frame).

ChVector3d	GetBallJointPosUCA (VehicleSide side)
	Get position of the UCA ball joint (expressed in the global frame).

virtual void	LogConstraintViolations (VehicleSide side) override
	Log current constraint violations.

virtual std::shared_ptr< ChBody >	GetAntirollBody (VehicleSide side) const override
	Specify the suspension body on the specified side to attach a possible antirollbar subsystem. More...

void	LogHardpointLocations (const ChVector3d &ref, bool inches=false)
	Log the locations of all hardpoints. More...

Public Member Functions inherited from chrono::vehicle::ChSuspension
const ChVector3d &	GetRelPosition () const
	Get the location of the suspension subsystem relative to the associated chassis reference frame. More...

std::shared_ptr< ChBody >	GetSpindle (VehicleSide side) const
	Get a handle to the spindle body on the specified side.

std::shared_ptr< ChShaft >	GetAxle (VehicleSide side) const
	Get a handle to the axle shaft on the specified side.

std::shared_ptr< ChLinkLockRevolute >	GetRevolute (VehicleSide side) const
	Get a handle to the revolute joint on the specified side.

const ChVector3d &	GetSpindlePos (VehicleSide side) const
	Get the global location of the spindle on the specified side.

ChQuaternion	GetSpindleRot (VehicleSide side) const
	Get the orientation of the spindle body on the specified side. More...

const ChVector3d &	GetSpindleLinVel (VehicleSide side) const
	Get the linear velocity of the spindle body on the specified side. More...

ChVector3d	GetSpindleAngVel (VehicleSide side) const
	Get the angular velocity of the spindle body on the specified side. More...

double	GetAxleSpeed (VehicleSide side) const
	Get the angular speed of the axle on the specified side.

virtual void	Synchronize (double time)
	Synchronize this suspension subsystem.

virtual void	Advance (double step)
	Advance the state of the suspension subsystem by the specified time step.

void	ApplyAxleTorque (VehicleSide side, double torque)
	Apply the provided motor torque. More...

virtual double	getSpindleRadius () const =0
	Return the radius of the spindle body (visualization only).

virtual double	getSpindleWidth () const =0
	Return the width of the spindle body (visualization only).

virtual std::shared_ptr< ChBody >	GetBrakeBody (VehicleSide side) const
	Specify the body on the specified side for a possible connection to brake subsystem. More...

virtual std::vector< ForceRSDA >	ReportSuspensionTorque (VehicleSide side) const
	Return current RSDA torque information on the specified side.

void	ApplyParkingBrake (bool brake)
	Simple model of a parking brake.

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.

Protected Types
enum	PointId { SPINDLE, UPRIGHT, UCA_F, UCA_B, UCA_U, UCA_CM, LCA_F, LCA_B, LCA_U, LCA_CM, SHOCK_C, SHOCK_A, SPRING_C, SPRING_A, TIEROD_C, TIEROD_U, NUM_POINTS }
	Identifiers for the various hardpoints. More...

Protected Member Functions
	ChDoubleWishbone (const std::string &name, bool vehicle_frame_inertia=false)
	Protected constructor. More...

void	SetVehicleFrameInertiaFlag (bool val)
	Indicate whether or not inertia matrices are specified with respect to a vehicle-aligned centroidal frame (flag=true) or with respect to the body centroidal frame (flag=false). More...

virtual void	InitializeInertiaProperties () override
	Initialize subsystem inertia properties. More...

virtual void	UpdateInertiaProperties () override
	Update subsystem inertia properties. More...

virtual bool	UseTierodBodies () const
	Indicate whether or not tirod bodies are modelled (default: false). More...

virtual const ChVector3d	getLocation (PointId which)=0
	Return the location of the specified hardpoint. More...

virtual double	getCamberAngle () const
	Return the camber angle, in radians (default: 0).

virtual double	getToeAngle () const
	Return the toe angle, in radians (default: 0). More...

virtual double	getSpindleMass () const =0
	Return the mass of the spindle body.

virtual double	getUCAMass () const =0
	Return the mass of the upper control arm body.

virtual double	getLCAMass () const =0
	Return the mass of the lower control body.

virtual double	getUprightMass () const =0
	Return the mass of the upright body.

virtual double	getTierodMass () const
	Return the mass of the tierod body.

virtual const ChVector3d &	getSpindleInertia () const =0
	Return the moments of inertia of the spindle body.

virtual const ChVector3d &	getUCAInertiaMoments () const =0
	Return the moments of inertia of the upper control arm body.

virtual const ChVector3d &	getUCAInertiaProducts () const =0
	Return the products of inertia of the upper control arm body.

virtual const ChVector3d &	getLCAInertiaMoments () const =0
	Return the moments of inertia of the lower control arm body.

virtual const ChVector3d &	getLCAInertiaProducts () const =0
	Return the products of inertia of the lower control arm body.

virtual const ChVector3d &	getUprightInertiaMoments () const =0
	Return the moments of inertia of the upright body.

virtual const ChVector3d &	getUprightInertiaProducts () const =0
	Return the products of inertia of the upright body.

virtual const ChVector3d	getTierodInertia () const
	Return the moments of inertia of the tierod body.

virtual double	getAxleInertia () const =0
	Return the inertia of the axle shaft.

virtual double	getUCARadius () const =0
	Return the radius of the upper control arm body (visualization only).

virtual double	getLCARadius () const =0
	Return the radius of the lower control arm body (visualization only).

virtual double	getUprightRadius () const =0
	Return the radius of the upright body (visualization only).

virtual double	getTierodRadius () const
	Return the radius of the tierod body (visualization only).

virtual double	getSpringRestLength () const =0
	Return the free (rest) length of the spring element.

virtual double	getShockRestLength () const
	Return the free (rest) length of the shock element.

virtual std::shared_ptr< ChLinkTSDA::ForceFunctor >	getSpringForceFunctor () const =0
	Return the functor object for spring force.

virtual std::shared_ptr< ChLinkTSDA::ForceFunctor >	getShockForceFunctor () const =0
	Return the functor object for shock force.

virtual std::shared_ptr< ChVehicleBushingData >	getUCABushingData () const
	Return stiffness and damping data for the UCA bushing. More...

virtual std::shared_ptr< ChVehicleBushingData >	getLCABushingData () const
	Return stiffness and damping data for the LCA bushing. More...

virtual std::shared_ptr< ChVehicleBushingData >	getTierodBushingData () const
	Return stiffness and damping data for the tierod bushings. More...

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

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_upright [2]
	upright bodies (left/right)

std::shared_ptr< ChBody >	m_UCA [2]
	upper control arm bodies (left/right)

std::shared_ptr< ChBody >	m_LCA [2]
	lower control arm bodies (left/right)

std::shared_ptr< ChBody >	m_tierod [2]
	tierod bodies, if used (left/right)

std::shared_ptr< ChVehicleJoint >	m_revoluteUCA [2]
	chassis-UCA revolute joints (left/right)

std::shared_ptr< ChVehicleJoint >	m_sphericalUCA [2]
	upright-UCA spherical joints (left/right)

std::shared_ptr< ChVehicleJoint >	m_revoluteLCA [2]
	chassis-LCA revolute joints (left/right)

std::shared_ptr< ChVehicleJoint >	m_sphericalLCA [2]
	upright-LCA spherical joints (left/right)

std::shared_ptr< ChLinkDistance >	m_distTierod [2]
	tierod distance constraints (left/right)

std::shared_ptr< ChVehicleJoint >	m_sphericalTierod [2]
	tierod-upright spherical joints (left/right)

std::shared_ptr< ChVehicleJoint >	m_universalTierod [2]
	tierod-chassis universal joints (left/right)

std::shared_ptr< ChLinkTSDA >	m_shock [2]
	spring links (left/right)

std::shared_ptr< ChLinkTSDA >	m_spring [2]
	shock links (left/right)

Protected Attributes inherited from chrono::vehicle::ChSuspension
ChVector3d	m_rel_loc
	location relative to chassis

std::shared_ptr< ChBody >	m_spindle [2]
	handles to spindle bodies

std::shared_ptr< ChShaft >	m_axle [2]
	handles to axle shafts

std::shared_ptr< ChShaftBodyRotation >	m_axle_to_spindle [2]
	handles to spindle-shaft connectors

std::shared_ptr< ChLinkLockRevolute >	m_revolute [2]
	handles to spindle revolute joints

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

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 Enumeration Documentation

◆ PointId

enum chrono::vehicle::ChDoubleWishbone::PointId

protected

Identifiers for the various hardpoints.

Enumerator
SPINDLE	spindle location
UPRIGHT	upright location
UCA_F	upper control arm, chassis front
UCA_B	upper control arm, chassis back
UCA_U	upper control arm, upright
UCA_CM	upper control arm, center of mass
LCA_F	lower control arm, chassis front
LCA_B	lower control arm, chassis back
LCA_U	lower control arm, upright
LCA_CM	lower control arm, center of mass
SHOCK_C	shock, chassis
SHOCK_A	shock, lower control arm
SPRING_C	spring, chassis
SPRING_A	spring, lower control arm
TIEROD_C	tierod, chassis
TIEROD_U	tierod, upright

Constructor & Destructor Documentation

◆ ChDoubleWishbone()

chrono::vehicle::ChDoubleWishbone::ChDoubleWishbone	(	const std::string &	name,
		bool	vehicle_frame_inertia = `false`
	)

protected

Protected constructor.

Parameters

[in]	name	name of the subsystem
[in]	vehicle_frame_inertia	inertia specified in vehicle-aligned centroidal frames?

Member Function Documentation

◆ AddVisualizationAssets()

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

overridevirtual

Add visualization assets for the suspension subsystem.

This default implementation uses primitives.

Reimplemented from chrono::vehicle::ChSuspension.

◆ GetAntirollBody()

virtual std::shared_ptr<ChBody> chrono::vehicle::ChDoubleWishbone::GetAntirollBody ( VehicleSide side ) const

inlineoverridevirtual

Specify the suspension body on the specified side to attach a possible antirollbar subsystem.

Return the corresponding lower control arm.

Reimplemented from chrono::vehicle::ChSuspension.

◆ getLCABushingData()

virtual std::shared_ptr<ChVehicleBushingData> chrono::vehicle::ChDoubleWishbone::getLCABushingData ( ) const

inlineprotectedvirtual

Return stiffness and damping data for the LCA bushing.

Returning nullptr (default) results in using a kinematic revolute joint.

Reimplemented in chrono::vehicle::DoubleWishbone.

◆ getLocation()

virtual const ChVector3d chrono::vehicle::ChDoubleWishbone::getLocation ( PointId which )

protectedpure virtual

Return the location of the specified hardpoint.

The returned location must be expressed in the suspension reference frame.

Implemented in chrono::vehicle::generic::Generic_DoubleWishbone, and chrono::vehicle::sedan::Sedan_DoubleWishbone.

◆ getTierodBushingData()

virtual std::shared_ptr<ChVehicleBushingData> chrono::vehicle::ChDoubleWishbone::getTierodBushingData ( ) const

inlineprotectedvirtual

Return stiffness and damping data for the tierod bushings.

Used only if tierod bodies are defined (see UseTierodBody). Returning nullptr (default) results in using kinematic joints (spherical + universal).

Reimplemented in chrono::vehicle::DoubleWishbone.

◆ getToeAngle()

virtual double chrono::vehicle::ChDoubleWishbone::getToeAngle ( ) const

inlineprotectedvirtual

Return the toe angle, in radians (default: 0).

A positive value indicates toe-in, a negative value indicates toe-out.

Reimplemented in chrono::vehicle::generic::Generic_DoubleWishboneRear, chrono::vehicle::feda::FEDA_DoubleWishboneRear, chrono::vehicle::hmmwv::HMMWV_DoubleWishboneRear, chrono::vehicle::mrole::mrole_DoubleWishboneRear, chrono::vehicle::artcar::ARTcar_DoubleWishboneRear, chrono::vehicle::generic::Generic_DoubleWishboneFront, chrono::vehicle::bmw::BMW_E90_DoubleWishbone, chrono::vehicle::generic::Generic_DoubleWishbone, chrono::vehicle::sedan::Sedan_DoubleWishbone, chrono::vehicle::artcar::ARTcar_DoubleWishboneFront, chrono::vehicle::feda::FEDA_DoubleWishboneFront, chrono::vehicle::hmmwv::HMMWV_DoubleWishboneFront, chrono::vehicle::mrole::mrole_DoubleWishboneFront, and chrono::vehicle::DoubleWishbone.

◆ getUCABushingData()

virtual std::shared_ptr<ChVehicleBushingData> chrono::vehicle::ChDoubleWishbone::getUCABushingData ( ) const

inlineprotectedvirtual

Return stiffness and damping data for the UCA bushing.

Returning nullptr (default) results in using a kinematic revolute joint.

Reimplemented in chrono::vehicle::DoubleWishbone.

◆ Initialize()

void chrono::vehicle::ChDoubleWishbone::Initialize	(	std::shared_ptr< ChChassis >	chassis,
		std::shared_ptr< ChSubchassis >	subchassis,
		std::shared_ptr< ChSteering >	steering,
		const ChVector3d &	location,
		double	left_ang_vel = `0`,
		double	right_ang_vel = `0`
	)

overridevirtual

Initialize this suspension subsystem.

The suspension subsystem is initialized by attaching it to the specified chassis and (if provided) to the specified subchassis, at the specified location (with respect to and expressed in the reference frame of the chassis). It is assumed that the suspension reference frame is always aligned with the chassis reference frame. If a steering subsystem is provided, the suspension tierods are to be attached to the steering's central link body (steered suspension); otherwise they are to be attached to the chassis (non-steered suspension).

Parameters

[in]	chassis	associated chassis subsystem
[in]	subchassis	associated subchassis subsystem (may be null)
[in]	steering	associated steering subsystem (may be null)
[in]	location	location relative to the chassis frame
[in]	left_ang_vel	initial angular velocity of left wheel
[in]	right_ang_vel	initial angular velocity of right wheel

Reimplemented from chrono::vehicle::ChSuspension.

Reimplemented in chrono::vehicle::feda::FEDA_DoubleWishboneRear, and chrono::vehicle::feda::FEDA_DoubleWishboneFront.

◆ InitializeInertiaProperties()

void chrono::vehicle::ChDoubleWishbone::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.

◆ LogHardpointLocations()

void chrono::vehicle::ChDoubleWishbone::LogHardpointLocations	(	const ChVector3d &	ref,
		bool	inches = `false`
	)

Log the locations of all hardpoints.

The reported locations are expressed in the suspension reference frame. By default, these values are reported in SI units (meters), but can be optionally reported in inches.

◆ SetVehicleFrameInertiaFlag()

void chrono::vehicle::ChDoubleWishbone::SetVehicleFrameInertiaFlag ( bool val )

inlineprotected

Indicate whether or not inertia matrices are specified with respect to a vehicle-aligned centroidal frame (flag=true) or with respect to the body centroidal frame (flag=false).

Note that this function must be called before Initialize().

◆ UpdateInertiaProperties()

void chrono::vehicle::ChDoubleWishbone::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.

◆ UseTierodBodies()

virtual bool chrono::vehicle::ChDoubleWishbone::UseTierodBodies ( ) const

inlineprotectedvirtual

Indicate whether or not tirod bodies are modelled (default: false).

If false, tierods are modelled using distance constraints. If true, rigid tierod bodies are created (in which case a derived class must provide the mass and inertia) and connected either with kinematic joints or bushings (depending on whether or not bushing data is defined).

Reimplemented in chrono::vehicle::generic::Generic_DoubleWishboneRear, chrono::vehicle::feda::FEDA_DoubleWishboneRear, chrono::vehicle::hmmwv::HMMWV_DoubleWishboneRear, chrono::vehicle::generic::Generic_DoubleWishboneFront, chrono::vehicle::bmw::BMW_E90_DoubleWishbone, chrono::vehicle::feda::FEDA_DoubleWishboneFront, chrono::vehicle::hmmwv::HMMWV_DoubleWishboneFront, and chrono::vehicle::DoubleWishbone.

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

/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/suspension/ChDoubleWishbone.h
/builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/suspension/ChDoubleWishbone.cpp

Description

Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Additional Inherited Members

Member Enumeration Documentation

◆ PointId

Constructor & Destructor Documentation

◆ ChDoubleWishbone()

Member Function Documentation

◆ AddVisualizationAssets()

◆ GetAntirollBody()

◆ getLCABushingData()

◆ getLocation()

◆ getTierodBushingData()

◆ getToeAngle()

◆ getUCABushingData()

◆ Initialize()

◆ InitializeInertiaProperties()

◆ LogHardpointLocations()

◆ SetVehicleFrameInertiaFlag()

◆ UpdateInertiaProperties()

◆ UseTierodBodies()