Description

Base class for a solid axle 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 supspension and will be mirrored (reflecting the y coordinates) to construct the right side.

#include <ChSolidAxle.h>

Inheritance diagram for chrono::vehicle::ChSolidAxle:
Collaboration diagram for chrono::vehicle::ChSolidAxle:

Public Member Functions

 ChSolidAxle (const std::string &name)
 
virtual bool IsSteerable () const finaloverride
 Specify whether or not this suspension can be steered.
 
virtual bool IsIndependent () const finaloverride
 Specify whether or not this is an independent suspension.
 
virtual void Initialize (std::shared_ptr< ChBodyAuxRef > chassis, const ChVector<> &location, std::shared_ptr< ChBody > tierod_body, 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 GetMass () const override
 Get the total mass of the suspension subsystem.
 
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.
 
virtual void LogConstraintViolations (VehicleSide side) override
 Log current constraint violations.
 
void LogHardpointLocations (const ChVector<> &ref, bool inches=false)
 
- Public Member Functions inherited from chrono::vehicle::ChSuspension
 ChSuspension (const std::string &name)
 
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
< ChLinkLockRevolute
GetRevolute (VehicleSide side) const
 Get a handle to the revolute joint on the specified side.
 
const ChVectorGetSpindlePos (VehicleSide side) const
 Get the global location of the spindle on the specified side.
 
const ChQuaternionGetSpindleRot (VehicleSide side) const
 Get the orientation of the spindle body on the specified side. More...
 
const ChVectorGetSpindleLinVel (VehicleSide side) const
 Get the linear velocity of the spindle body on the specified side. More...
 
ChVector 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.
 
void Synchronize (VehicleSide side, const TireForce &tire_force)
 Update the suspension subsystem: apply the provided tire forces. More...
 
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< ChBodyGetLeftBody () const
 Specify the left body for a possible antirollbar subsystem. More...
 
virtual std::shared_ptr< ChBodyGetRightBody () const
 Specify the right body for a possible antirollbar subsystem. 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 track shoe subsystem.
 
void SetName (const std::string &name)
 Set the name identifier for this track shoe 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.
 

Protected Types

enum  PointId {
  SHOCK_A, SHOCK_C, KNUCKLE_L, KNUCKLE_U,
  LL_A, LL_C, UL_A, UL_C,
  SPRING_A, SPRING_C, TIEROD_K, SPINDLE,
  KNUCKLE_CM, LL_CM, UL_CM, BELLCRANK_TIEROD,
  BELLCRANK_AXLE, BELLCRANK_DRAGLINK, DRAGLINK_C, NUM_POINTS
}
 Identifiers for the various hardpoints. More...
 

Protected Member Functions

virtual const ChVector getLocation (PointId which)=0
 Return the location of the specified hardpoint. More...
 
virtual const ChVector getAxleTubeCOM () const =0
 Return the center of mass of the axle tube.
 
virtual double getAxleTubeMass () const =0
 Return the mass of the axle tube body.
 
virtual double getSpindleMass () const =0
 Return the mass of the spindle body.
 
virtual double getULMass () const =0
 Return the mass of the upper link body.
 
virtual double getLLMass () const =0
 Return the mass of the lower link body.
 
virtual double getKnuckleMass () const =0
 Return the mass of the knuckle body.
 
virtual double getTierodMass () const =0
 Return the mass of the tierod body.
 
virtual double getDraglinkMass () const =0
 Return the mass of the draglink body.
 
virtual double getBellCrankMass () const =0
 Return the mass of the bell crank body.
 
virtual double getAxleTubeRadius () const =0
 Return the radius of the axle tube body (visualization only).
 
virtual double getULRadius () const =0
 Return the radius of the upper link body (visualization only).
 
virtual double getLLRadius () const =0
 Return the radius of the lower link body (visualization only).
 
virtual double getKnuckleRadius () const =0
 Return the radius of the knuckle body (visualization only).
 
virtual double getTierodRadius () const =0
 Return the radius of the tierod body (visualization only).
 
virtual double getDraglinkRadius () const =0
 Return the radius of the draglink body (visualization only).
 
virtual double getBellCrankRadius () const =0
 Return the radius of the bell crank body (visualization only).
 
virtual const ChVectorgetAxleTubeInertia () const =0
 Return the moments of inertia of the axle tube body.
 
virtual const ChVectorgetSpindleInertia () const =0
 Return the moments of inertia of the spindle body.
 
virtual const ChVectorgetULInertia () const =0
 Return the moments of inertia of the upper link body.
 
virtual const ChVectorgetLLInertia () const =0
 Return the moments of inertia of the lower link body.
 
virtual const ChVectorgetKnuckleInertia () const =0
 Return the moments of inertia of the knuckle body.
 
virtual const ChVectorgetTierodInertia () const =0
 Return the moments of inertia of the tierod body.
 
virtual const ChVectorgetDraglinkInertia () const =0
 Return the moments of inertia of the draglink body.
 
virtual const ChVectorgetBellCrankInertia () const =0
 Return the moments of inertia of the bell crank body.
 
virtual double getAxleInertia () const =0
 Return the inertia of the axle shaft.
 
virtual double getSpringRestLength () const =0
 Return the free (rest) length of the spring element.
 
virtual ChSpringForceCallbackgetSpringForceCallback () const =0
 Return the callback function for spring force.
 
virtual ChSpringForceCallbackgetShockForceCallback () const =0
 Return the callback function for shock force.
 

Protected Attributes

std::shared_ptr< ChBodym_axleTube
 handles to the axle tube body
 
std::shared_ptr< ChBodym_tierod
 handles to the tierod body
 
std::shared_ptr< ChBodym_bellCrank
 handles to the bellcrank body
 
std::shared_ptr< ChBodym_draglink
 handles to the draglink body
 
std::shared_ptr< ChBodym_knuckle [2]
 handles to the knuckle bodies (left/right)
 
std::shared_ptr< ChBodym_upperLink [2]
 handles to the upper link bodies (left/right)
 
std::shared_ptr< ChBodym_lowerLink [2]
 handles to the lower link bodies (left/right)
 
std::shared_ptr
< ChLinkLockRevolute
m_revoluteKingpin [2]
 handles to the knuckle-axle tube revolute joints (left/right)
 
std::shared_ptr
< ChLinkLockRevolute
m_revoluteBellCrank
 handles to the bellCrank-axle revolute joint (left)
 
std::shared_ptr
< ChLinkLockSpherical
m_sphericalTierod
 handles to the knuckle-tierod spherical joint (left)
 
std::shared_ptr
< ChLinkLockSpherical
m_sphericalDraglink
 handles to the draglink-chassis spherical joint (left)
 
std::shared_ptr< ChLinkUniversalm_universalDraglink
 handles to the draglink-bellCrank universal joint (left)
 
std::shared_ptr< ChLinkUniversalm_universalTierod
 handles to the knuckle-tierod universal joint (right)
 
std::shared_ptr
< ChLinkLockSpherical
m_sphericalUpperLink [2]
 handles to the upper link-axle tube spherical joints (left/right)
 
std::shared_ptr
< ChLinkLockSpherical
m_sphericalLowerLink [2]
 handles to the lower link-axle tube spherical joints (left/right)
 
std::shared_ptr< ChLinkUniversalm_universalUpperLink [2]
 handles to the upper link-chassis universal joints (left/right)
 
std::shared_ptr< ChLinkUniversalm_universalLowerLink [2]
 handles to the lower link-chassis universal joints (left/right)
 
std::shared_ptr
< ChLinkLockPointPlane
m_pointPlaneBellCrank
 handles to the bellCrank-tierod point-plane joint (left)
 
std::shared_ptr< ChLinkSpringCBm_shock [2]
 handles to the spring links (left/right)
 
std::shared_ptr< ChLinkSpringCBm_spring [2]
 handles to the shock links (left/right)
 
- Protected Attributes inherited from chrono::vehicle::ChSuspension
std::shared_ptr< ChBodym_spindle [2]
 handles to spindle bodies
 
std::shared_ptr< ChShaftm_axle [2]
 handles to axle shafts
 
std::shared_ptr< ChShaftsBodym_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
 
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
 

Member Enumeration Documentation

Identifiers for the various hardpoints.

Enumerator
SHOCK_A 

shock, axle

SHOCK_C 

shock, chassis

KNUCKLE_L 

lower knuckle point

KNUCKLE_U 

upper knuckle point

LL_A 

lower link, axle

LL_C 

lower link, chassis

UL_A 

upper link, axle

UL_C 

upper link, chassis

SPRING_A 

spring, axle

SPRING_C 

spring, chassis

TIEROD_K 

tierod, knuckle

SPINDLE 

spindle location

KNUCKLE_CM 

knuckle, center of mass

LL_CM 

lower link, center of mass

UL_CM 

upper link, center of mass

BELLCRANK_TIEROD 

bell crank to tierod

BELLCRANK_AXLE 

bell crank to axle

BELLCRANK_DRAGLINK 

bell crank to draglink'

DRAGLINK_C 

draglink, chassis

Constructor & Destructor Documentation

chrono::vehicle::ChSolidAxle::ChSolidAxle ( const std::string &  name)
Parameters
[in]namename of the subsystem

Member Function Documentation

void chrono::vehicle::ChSolidAxle::AddVisualizationAssets ( VisualizationType  vis)
overridevirtual

Add visualization assets for the suspension subsystem.

This default implementation uses primitives.

Reimplemented from chrono::vehicle::ChSuspension.

virtual const ChVector chrono::vehicle::ChSolidAxle::getLocation ( PointId  which)
protectedpure virtual

Return the location of the specified hardpoint.

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

void chrono::vehicle::ChSolidAxle::Initialize ( std::shared_ptr< ChBodyAuxRef chassis,
const ChVector<> &  location,
std::shared_ptr< ChBody tierod_body,
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 body 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. Finally, tierod_body is a handle to the body to which the suspension tierods are to be attached. For a steerable suspension, this will be the steering link of a suspension subsystem. Otherwise, this is the chassis.

Parameters
[in]chassishandle to the chassis body
[in]locationlocation relative to the chassis frame
[in]tierod_bodybody to which tireods are connected
[in]left_ang_velinitial angular velocity of left wheel
[in]right_ang_velinitial angular velocity of right wheel

Implements chrono::vehicle::ChSuspension.