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:
Collaboration diagram for chrono::vehicle::ChDoubleWishbone:

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< ChLinkTSDAGetSpring (VehicleSide side) const
 Get a handle to the specified spring element.
 
std::shared_ptr< ChLinkTSDAGetShock (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< ChBodyGetAntirollBody (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 ChVector3dGetRelPosition () const
 Get the location of the suspension subsystem relative to the associated chassis reference frame. More...
 
std::shared_ptr< ChBodyGetSpindle (VehicleSide side) const
 Get a handle to the spindle body on the specified side.
 
std::shared_ptr< ChShaftGetAxle (VehicleSide side) const
 Get a handle to the axle shaft on the specified side.
 
std::shared_ptr< ChLinkLockRevoluteGetRevolute (VehicleSide side) const
 Get a handle to the revolute joint on the specified side.
 
const ChVector3dGetSpindlePos (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 ChVector3dGetSpindleLinVel (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< ChBodyGetBrakeBody (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 ChFrameGetCOMFrame () const
 Get the current subsystem COM frame (relative to and expressed in the subsystem's reference frame). More...
 
const ChMatrix33GetInertia () const
 Get the current subsystem inertia (relative to the subsystem COM frame). More...
 
const ChFrameGetTransform () 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 ChVector3dgetSpindleInertia () const =0
 Return the moments of inertia of the spindle body.
 
virtual const ChVector3dgetUCAInertiaMoments () const =0
 Return the moments of inertia of the upper control arm body.
 
virtual const ChVector3dgetUCAInertiaProducts () const =0
 Return the products of inertia of the upper control arm body.
 
virtual const ChVector3dgetLCAInertiaMoments () const =0
 Return the moments of inertia of the lower control arm body.
 
virtual const ChVector3dgetLCAInertiaProducts () const =0
 Return the products of inertia of the lower control arm body.
 
virtual const ChVector3dgetUprightInertiaMoments () const =0
 Return the moments of inertia of the upright body.
 
virtual const ChVector3dgetUprightInertiaProducts () 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::ForceFunctorgetSpringForceFunctor () const =0
 Return the functor object for spring force.
 
virtual std::shared_ptr< ChLinkTSDA::ForceFunctorgetShockForceFunctor () const =0
 Return the functor object for shock force.
 
virtual std::shared_ptr< ChVehicleBushingDatagetUCABushingData () const
 Return stiffness and damping data for the UCA bushing. More...
 
virtual std::shared_ptr< ChVehicleBushingDatagetLCABushingData () const
 Return stiffness and damping data for the LCA bushing. More...
 
virtual std::shared_ptr< ChVehicleBushingDatagetTierodBushingData () 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< ChBodym_upright [2]
 upright bodies (left/right)
 
std::shared_ptr< ChBodym_UCA [2]
 upper control arm bodies (left/right)
 
std::shared_ptr< ChBodym_LCA [2]
 lower control arm bodies (left/right)
 
std::shared_ptr< ChBodym_tierod [2]
 tierod bodies, if used (left/right)
 
std::shared_ptr< ChVehicleJointm_revoluteUCA [2]
 chassis-UCA revolute joints (left/right)
 
std::shared_ptr< ChVehicleJointm_sphericalUCA [2]
 upright-UCA spherical joints (left/right)
 
std::shared_ptr< ChVehicleJointm_revoluteLCA [2]
 chassis-LCA revolute joints (left/right)
 
std::shared_ptr< ChVehicleJointm_sphericalLCA [2]
 upright-LCA spherical joints (left/right)
 
std::shared_ptr< ChLinkDistancem_distTierod [2]
 tierod distance constraints (left/right)
 
std::shared_ptr< ChVehicleJointm_sphericalTierod [2]
 tierod-upright spherical joints (left/right)
 
std::shared_ptr< ChVehicleJointm_universalTierod [2]
 tierod-chassis universal joints (left/right)
 
std::shared_ptr< ChLinkTSDAm_shock [2]
 spring links (left/right)
 
std::shared_ptr< ChLinkTSDAm_spring [2]
 shock links (left/right)
 
- Protected Attributes inherited from chrono::vehicle::ChSuspension
ChVector3d m_rel_loc
 location relative to chassis
 
std::shared_ptr< ChBodym_spindle [2]
 handles to spindle bodies
 
std::shared_ptr< ChShaftm_axle [2]
 handles to axle shafts
 
std::shared_ptr< ChShaftBodyRotationm_axle_to_spindle [2]
 handles to spindle-shaft connectors
 
std::shared_ptr< ChLinkLockRevolutem_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< ChPartm_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

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]namename of the subsystem
[in]vehicle_frame_inertiainertia 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()

◆ 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]chassisassociated chassis subsystem
[in]subchassisassociated subchassis subsystem (may be null)
[in]steeringassociated steering subsystem (may be null)
[in]locationlocation relative to the chassis frame
[in]left_ang_velinitial angular velocity of left wheel
[in]right_ang_velinitial 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