chrono::ChShaftsMotor Class Reference

Description

Class for defining a 'motor' (a 1D model of 'imposed torque' or 'imposed velocity' or 'imposed rotation') between two one-degree-of-freedom parts, that is, shafts that can be used to build 1D models of power trains.

This is more efficient than simulating power trains modeled with full 3D ChBody objects. Note, it is not inherited from ChShaftsTorqueBase because it might introduce also a constraint, in case it is working in MOT_MODE_ROTATION or MOT_MODE_SPEED.

#include <ChShaftsMotor.h>

Inheritance diagram for chrono::ChShaftsMotor:
Collaboration diagram for chrono::ChShaftsMotor:

Public Types

enum  eCh_shaftsmotor_mode { MOT_MODE_ROTATION = 0, MOT_MODE_SPEED, MOT_MODE_TORQUE }
 

Public Member Functions

 ChShaftsMotor (const ChShaftsMotor &other)
 
virtual ChShaftsMotorClone () const override
 "Virtual" copy constructor (covariant return type).
 
virtual int GetDOC_c () override
 Number of scalar constraints.
 
virtual void IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L) override
 From item's reaction forces to global reaction vector.
 
virtual void IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L) override
 From global reaction vector to item's reaction forces.
 
virtual void IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
 Takes the F force term, scale and adds to R at given offset: R += c*F.
 
virtual void IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c) override
 Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.
 
virtual void IntLoadConstraint_C (const unsigned int off, ChVectorDynamic<> &Qc, const double c, bool do_clamp, double recovery_clamp) override
 Takes the term C, scale and adds to Qc at given offset: Qc += c*C.
 
virtual void IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c) override
 Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct.
 
virtual void IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc) override
 Prepare variables and constraints for a solution: From a vector R into the F 'force' term of the variables From a vector Qc into the Qb 'constraint' term of the constraints From a vector v into the q 'unknowns' term of the variables (for warm starting) From a vector L into the L 'lagrangian ' term of the constraints (for warm starting)
 
virtual void IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L) override
 After a solver solution, fetch values from variables and constraints: To a vector v from the q 'unknowns' term of the variables To a vector L from the L 'lagrangian ' term of the constraints.
 
virtual void InjectConstraints (ChSystemDescriptor &mdescriptor) override
 Tell to a system descriptor that there are contraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. More...
 
virtual void ConstraintsBiReset () override
 Sets to zero the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false) override
 Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_Ct (double factor=1) override
 Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsFbLoadForces (double factor=1) override
 Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.
 
virtual void ConstraintsLoadJacobians () override
 Adds the current jacobians in encapsulated ChConstraints.
 
virtual void ConstraintsFetch_react (double factor=1) override
 Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...
 
bool Initialize (std::shared_ptr< ChShaft > mshaft1, std::shared_ptr< ChShaft > mshaft2) override
 Use this function after gear creation, to initialize it, given two shafts to join. More...
 
void SetMotorMode (eCh_shaftsmotor_mode mmode)
 Se the motor mode. More...
 
void SetMotorTorque (double mt)
 Set the motor torque applied between shaft2 and shaft1. More...
 
double GetMotorTorque () const
 Get the motor torque applied between shaft2 and shaft1.
 
double GetTorqueReactionOn1 () const override
 Get the reaction torque exchanged between the two shafts, considered as applied to the 1st axis. More...
 
double GetTorqueReactionOn2 () const override
 Get the reaction torque exchanged between the two shafts, considered as applied to the 2nd axis. More...
 
void SetMotorRot (double mt)
 Set the motor rotation phase between shaft2 and shaft1. More...
 
void SetMotorRot_dt (double mt)
 Set the motor rotation speed between shaft2 and shaft1. More...
 
double GetMotorRot () const
 Get the actual angle rotation of the motor, in terms of phase of shaft 1 respect to 2.
 
double GetMotorRot_dt () const
 Get the actual speed of the motor, in terms of speed of shaft 1 respect to 2.
 
double GetMotorRot_dtdt () const
 Get the actual acceleration of the motor, in terms of accel. of shaft 1 respect to 2.
 
virtual void Update (double mytime, bool update_assets=true) override
 Update all auxiliary data of the gear transmission at given time.
 
virtual void ArchiveOUT (ChArchiveOut &marchive) override
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIN (ChArchiveIn &marchive) override
 Method to allow deserialization of transient data from archives. More...
 
- Public Member Functions inherited from chrono::ChShaftsCouple
 ChShaftsCouple (const ChShaftsCouple &other)
 
virtual int GetNumCoords ()
 Get the number of scalar variables affected by constraints in this link.
 
ChShaftGetShaft1 ()
 Get the first (input) shaft.
 
ChShaftGetShaft2 ()
 Get the second (output) shaft.
 
double GetRelativeRotation () const
 Get the actual reative angle in terms of phase of shaft 1 respect to 2.
 
double GetRelativeRotation_dt () const
 Get the actual relative speed in terms of speed of shaft 1 respect to 2.
 
double GetRelativeRotation_dtdt () const
 Get the actual relative acceleration in terms of speed of shaft 1 respect to 2.
 
- Public Member Functions inherited from chrono::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
ChSystemGetSystem () const
 Get the pointer to the parent ChSystem()
 
virtual void SetSystem (ChSystem *m_system)
 Set the pointer to the parent ChSystem() and also add to new collision system / remove from old coll.system.
 
void AddAsset (std::shared_ptr< ChAsset > masset)
 Add an optional asset (it can be used to define visualization shapes, es ChSphereShape, or textures, or custom attached properties that the user can define by creating his class inherited from ChAsset)
 
std::vector< std::shared_ptr
< ChAsset > > & 
GetAssets ()
 Access to the list of optional assets.
 
std::shared_ptr< ChAssetGetAssetN (unsigned int num)
 Access the Nth asset in the list of optional assets.
 
virtual ChFrame GetAssetsFrame (unsigned int nclone=0)
 Get the master coordinate system for assets that have some geometric meaning. More...
 
virtual unsigned int GetAssetsFrameNclones ()
 Optionally, a ChPhysicsItem can return multiple asset coordinate systems; this can be helpful if, for example, when a ChPhysicsItem contains 'clones' with the same assets (ex. More...
 
virtual bool GetCollide () const
 Tell if the object is subject to collision. More...
 
virtual void SyncCollisionModels ()
 If this physical item contains one or more collision models, sinchronize their coordinates and bounding boxes to the state of the item. More...
 
virtual void AddCollisionModelsToSystem ()
 If this physical item contains one or more collision models, add them to the system's collision engine. More...
 
virtual void RemoveCollisionModelsFromSystem ()
 If this physical item contains one or more collision models, remove them from the system's collision engine. More...
 
virtual void GetTotalAABB (ChVector<> &bbmin, ChVector<> &bbmax)
 Get the entire AABB axis-aligned bounding box of the object. More...
 
virtual void GetCenter (ChVector<> &mcenter)
 Get a symbolic 'center' of the object. More...
 
virtual void StreamINstate (ChStreamInBinary &mstream)
 Method to deserialize only the state (position, speed) Must be implemented by child classes. More...
 
virtual void StreamOUTstate (ChStreamOutBinary &mstream)
 Method to serialize only the state (position, speed) Must be implemented by child classes. More...
 
virtual void Setup ()
 This might recompute the number of coordinates, DOFs, constraints, in case this might change (ex in ChAssembly), as well as state offsets of contained items (ex in ChMesh)
 
virtual void Update (bool update_assets=true)
 As above, but does not require updating of time-dependent data. More...
 
virtual void SetNoSpeedNoAcceleration ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual int GetDOF ()
 Get the number of scalar coordinates (variables), if any, in this item. More...
 
virtual int GetDOF_w ()
 Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. More...
 
virtual int GetDOC ()
 Get the number of scalar constraints, if any, in this item.
 
virtual int GetDOC_d ()
 Get the number of scalar constraints, if any, in this item (only unilateral constr.) Children classes might override this. More...
 
unsigned int GetOffset_x ()
 Get offset in the state vector (position part)
 
unsigned int GetOffset_w ()
 Get offset in the state vector (speed part)
 
unsigned int GetOffset_L ()
 Get offset in the lagrangian multipliers.
 
void SetOffset_x (const unsigned int moff)
 Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_w (const unsigned int moff)
 Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_L (const unsigned int moff)
 Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.
 
virtual void IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T)
 From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...
 
virtual void IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T)
 From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...
 
virtual void IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a)
 From item's state acceleration to global acceleration vector. More...
 
virtual void IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a)
 From global acceleration vector to item's state acceleration. More...
 
virtual void IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)
 Computes x_new = x + Dt , using vectors at specified offsets. More...
 
virtual void IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c)
 Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w. More...
 
virtual void VariablesFbReset ()
 Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.
 
virtual void VariablesFbLoadForces (double factor=1)
 Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.
 
virtual void VariablesQbLoadSpeed ()
 Initialize the 'qb' part of the ChVariables with the current value of speeds. More...
 
virtual void VariablesFbIncrementMq ()
 Adds M*q (masses multiplied current 'qb') to Fb, ex. More...
 
virtual void VariablesQbSetSpeed (double step=0)
 Fetches the item speed (ex. More...
 
virtual void VariablesQbIncrementPosition (double step)
 Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...
 
virtual void InjectVariables (ChSystemDescriptor &mdescriptor)
 Tell to a system descriptor that there are variables of type ChVariables in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. More...
 
virtual void ConstraintsBiLoad_Qc (double factor=1)
 Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void InjectKRMmatrices (ChSystemDescriptor &mdescriptor)
 Tell to a system descriptor that there are items of type ChKblock in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this. More...
 
virtual void KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor)
 Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...
 
- Public Member Functions inherited from chrono::ChObj
 ChObj (const ChObj &other)
 
int GetIdentifier () const
 Gets the numerical identifier of the object.
 
void SetIdentifier (int id)
 Sets the numerical identifier of the object.
 
double GetChTime () const
 Gets the simulation time of this object.
 
void SetChTime (double m_time)
 Sets the simulation time of this object.
 
const char * GetName () const
 Gets the name of the object as C Ascii null-terminated string -for reading only!
 
void SetName (const char myname[])
 Sets the name of this object, as ascii string.
 
std::string GetNameString () const
 Gets the name of the object as C Ascii null-terminated string.
 
void SetNameString (const std::string &myname)
 Sets the name of this object, as std::string.
 
void MFlagsSetAllOFF (int &mflag)
 
void MFlagsSetAllON (int &mflag)
 
void MFlagSetON (int &mflag, int mask)
 
void MFlagSetOFF (int &mflag, int mask)
 
int MFlagGet (int &mflag, int mask)
 

Public Attributes

enum
chrono::ChShaftsMotor::eCh_shaftsmotor_mode 
motor_mode
 

Additional Inherited Members

- Protected Attributes inherited from chrono::ChShaftsCouple
ChShaftshaft1
 first shaft
 
ChShaftshaft2
 second shaft
 
- Protected Attributes inherited from chrono::ChPhysicsItem
ChSystemsystem
 parent system
 
std::vector< std::shared_ptr
< ChAsset > > 
assets
 set of assets
 
unsigned int offset_x
 offset in vector of state (position part)
 
unsigned int offset_w
 offset in vector of state (speed part)
 
unsigned int offset_L
 offset in vector of lagrangian multipliers
 
- Protected Attributes inherited from chrono::ChObj
double ChTime
 the time of simulation for the object
 

Member Function Documentation

void chrono::ChShaftsMotor::ArchiveIN ( ChArchiveIn marchive)
overridevirtual

Method to allow deserialization of transient data from archives.

Method to allow de serialization of transient data from archives.

Reimplemented from chrono::ChShaftsCouple.

void chrono::ChShaftsMotor::ConstraintsFetch_react ( double  factor = 1)
overridevirtual

Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints.

Mostly used after the solver provided the solution in ChConstraints. Also, should convert the reactions obtained from dynamical simulation, from link space to intuitive react_force and react_torque.

Reimplemented from chrono::ChPhysicsItem.

double chrono::ChShaftsMotor::GetTorqueReactionOn1 ( ) const
overridevirtual

Get the reaction torque exchanged between the two shafts, considered as applied to the 1st axis.

Reimplemented from chrono::ChShaftsCouple.

double chrono::ChShaftsMotor::GetTorqueReactionOn2 ( ) const
overridevirtual

Get the reaction torque exchanged between the two shafts, considered as applied to the 2nd axis.

Reimplemented from chrono::ChShaftsCouple.

bool chrono::ChShaftsMotor::Initialize ( std::shared_ptr< ChShaft mshaft1,
std::shared_ptr< ChShaft mshaft2 
)
overridevirtual

Use this function after gear creation, to initialize it, given two shafts to join.

The first shaft is the 'output' shaft of the motor, the second is the 'truss', often fixed and not rotating. The torque is applied to the output shaft, while the truss shafts gets the same torque but with opposite sign. Each shaft must belong to the same ChSystem.

Parameters
mshaft1first shaft to join (motor output shaft)
mshaft2second shaft to join (motor truss)

Reimplemented from chrono::ChShaftsCouple.

void chrono::ChShaftsMotor::InjectConstraints ( ChSystemDescriptor mdescriptor)
overridevirtual

Tell to a system descriptor that there are contraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.

Reimplemented from chrono::ChPhysicsItem.

void chrono::ChShaftsMotor::SetMotorMode ( eCh_shaftsmotor_mode  mmode)

Se the motor mode.

The options are that you impose the relative torque between the two shafts, or their relative rotation phase, or their relative speed, but one mode excludes the others.

void chrono::ChShaftsMotor::SetMotorRot ( double  mt)

Set the motor rotation phase between shaft2 and shaft1.

If the rotation is not constant, you also must use SetMotorRot_dt() Note: use this only when in MOT_MODE_ROTATION !

void chrono::ChShaftsMotor::SetMotorRot_dt ( double  mt)

Set the motor rotation speed between shaft2 and shaft1.

Note: use this only when in MOT_MODE_ROTATION or MOT_MODE_SPEED !

void chrono::ChShaftsMotor::SetMotorTorque ( double  mt)

Set the motor torque applied between shaft2 and shaft1.

So, if fixed, shaft1 can be considered the reference, or the 'truss'. (The torque is applied with opposite sign to shaft 1). Note: use this only when in MOT_MODE_TORQUE !!