chrono::ChLinkMotorRotationDriveline Class Reference

Description

This is an "interface" from 3D to a powertrain/powertrain that is modeled via 1D elements such as ChShaft, ChShaftsMotor, ChShaftsGearbox, ChShaftsClutch, etc.

This is the most avanced type of "motor" because using many of those 1D elements one can build very complex drivelines, for example use this ChLinkMotorRotationDriveline to represent a drive+reducer, hence taking into account of the inertia of the motor shaft (as in many cases of robotic actuators, that has electric drives+reducers.) At the same time, using 1D elements avoids the unnecessary complication of using complete 3D parts to make fast spindles, 3D gears etc.

The 1D driveline is "interfaced" to the two connected threedimensional parts using two "inner" 1D shafts, each rotating as the connected 3D part; it is up to the user to build the driveline that connects those two shafts.

Most often the driveline is a graph starting at inner shaft 2 (consider it to be the truss for holding the motor drive, also the support for reducers if any) and ending at inner shaft 1 (consider it to be the output, i.e. the slow-rotation spindle). Note that it is up to the user to create a driveline where all torques are balanced action/reactions: in this case, GetMotorTorque() = GetInnerTorque1() = - GetInnerTorque2(). This is not true for example, for an unbalanced driveline where one of the two inner shafts is connected to some external ChShaft.

#include <ChLinkMotorRotationDriveline.h>

Inheritance diagram for chrono::ChLinkMotorRotationDriveline:
Collaboration diagram for chrono::ChLinkMotorRotationDriveline:

Public Member Functions

 ChLinkMotorRotationDriveline (const ChLinkMotorRotationDriveline &other)
 
virtual ChLinkMotorRotationDrivelineClone () const override
 "Virtual" copy constructor (covariant return type).
 
virtual void SetSystem (ChSystem *m_system) override
 Set the pointer to the parent ChSystem() and also add to new collision system / remove from old coll.system.
 
std::shared_ptr< ChShaftGetInnerShaft1 () const
 Access the inner 1D shaft connected to the rotation of body1 about dir of motor shaft. More...
 
std::shared_ptr< ChShaftGetInnerShaft2 () const
 Access the inner 1D shaft connected to the rotation of body2 about dir of motor shaft, The shaft can be connected to other shafts with ChShaftsClutch or similar items.
 
double GetInnerTorque1 () const
 Get the torque between body 1 and inner shaft 1. More...
 
double GetInnerTorque2 () const
 Get the torque between body 2 and inner shaft 2 Note, if driveline is not connected to outer 1D shafts, it should be GetInnerTorque2() = - GetInnerTorque1()
 
virtual double GetMotorTorque () const override
 Get the current actuator reaction torque [Nm].
 
virtual void Initialize (std::shared_ptr< ChBodyFrame > mbody1, std::shared_ptr< ChBodyFrame > mbody2, ChFrame<> mabsframe) override
 Initialize the generic mate, given the two bodies to be connected, and the absolute position of the mate (the two frames to connect on the bodies will be initially coincindent to that frame). More...
 
virtual void Initialize (std::shared_ptr< ChBodyFrame > mbody1, std::shared_ptr< ChBodyFrame > mbody2, bool pos_are_relative, ChFrame<> mframe1, ChFrame<> mframe2) override
 Specialized initialization for LinkMotorRotationDriveline, given the two bodies to be connected, the positions of the two frames to connect on the bodies (each expressed in body or abs. More...
 
virtual void Initialize (std::shared_ptr< ChBodyFrame > mbody1, std::shared_ptr< ChBodyFrame > mbody2, bool pos_are_relative, ChVector<> mpt1, ChVector<> mpt2, ChVector<> mnorm1, ChVector<> mnorm2) override
 Specialized initialization for LinkMotorRotationDriveline based on passing two vectors (point + dir) on the two bodies, which will represent the X axes of the two frames (Y and Z will be built from the X vector via Gram Schmidt orthonormalization). More...
 
virtual void Setup () override
 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 (double mytime, bool update_assets=true) override
 Update state of the LinkMotor.
 
virtual int GetDOF () override
 Get the number of scalar coordinates (variables), if any, in this item. More...
 
virtual int GetDOC () override
 Get the number of scalar constraints, if any, in this item.
 
virtual int GetDOC_c () override
 Get the number of scalar constraints, if any, in this item (only bilateral constr.) Children classes might override this.
 
virtual void IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T) override
 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, bool full_update) override
 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) override
 From item's state acceleration to global acceleration vector. More...
 
virtual void IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a) override
 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) override
 Computes x_new = x + Dt , using vectors at specified offsets. More...
 
virtual void IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L) override
 From item's reaction forces to global reaction vector. More...
 
virtual void IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L) override
 From global reaction vector to item's reaction forces. More...
 
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. More...
 
virtual void IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override
 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 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. More...
 
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. More...
 
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. More...
 
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 to accommodate a solution: More...
 
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 into vectors: More...
 
virtual void InjectConstraints (ChSystemDescriptor &mdescriptor) override
 Tell to a system descriptor that there are constraints of type ChConstraint in this object (for further passing it to a solver) Basically does nothing, but maybe that inherited classes may specialize this.
 
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 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...
 
virtual void InjectVariables (ChSystemDescriptor &mdescriptor) override
 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.
 
virtual void VariablesFbReset () override
 Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.
 
virtual void VariablesFbLoadForces (double factor=1) override
 Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.
 
virtual void VariablesQbLoadSpeed () override
 Initialize the 'qb' part of the ChVariables with the current value of speeds. More...
 
virtual void VariablesFbIncrementMq () override
 Adds M*q (masses multiplied current 'qb') to Fb, ex. More...
 
virtual void VariablesQbSetSpeed (double step=0) override
 Fetches the item speed (ex. More...
 
virtual void VariablesQbIncrementPosition (double step) override
 Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...
 
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::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
ChSystemGetSystem () const
 Get the pointer to the parent ChSystem()
 
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 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, synchronize their coordinates and bounding boxes to the state of the item.
 
virtual void AddCollisionModelsToSystem ()
 If this physical item contains one or more collision models, add them to the system's collision engine.
 
virtual void RemoveCollisionModelsFromSystem ()
 If this physical item contains one or more collision models, remove them from the system's collision engine.
 
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.
 
virtual void StreamOUTstate (ChStreamOutBinary &mstream)
 Method to serialize only the state (position, speed) Must be implemented by child classes.
 
virtual void SetNoSpeedNoAcceleration ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual int GetDOF_w ()
 Get the number of scalar coordinates of variables derivatives (usually = DOF, but might be different than DOF, ex. 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 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 ConstraintsFbLoadForces (double factor=1)
 Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by 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.
 
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)
 
virtual std::string & ArchiveContainerName ()
 

Additional Inherited Members

 Type of guide constraint.
- 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

◆ ArchiveIN()

void chrono::ChLinkMotorRotationDriveline::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::ChLinkMotorRotation.

◆ ConstraintsFetch_react()

void chrono::ChLinkMotorRotationDriveline::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::ChLinkMateGeneric.

◆ GetDOF()

int chrono::ChLinkMotorRotationDriveline::GetDOF ( )
overridevirtual

Get the number of scalar coordinates (variables), if any, in this item.

Children classes must override this.

Reimplemented from chrono::ChPhysicsItem.

◆ GetInnerShaft1()

std::shared_ptr<ChShaft> chrono::ChLinkMotorRotationDriveline::GetInnerShaft1 ( ) const
inline

Access the inner 1D shaft connected to the rotation of body1 about dir of motor shaft.

The shaft can be connected to other shafts with ChShaftsClutch or similar items.

◆ GetInnerTorque1()

double chrono::ChLinkMotorRotationDriveline::GetInnerTorque1 ( ) const
inline

Get the torque between body 1 and inner shaft 1.

Note: cohincident with GetMotorTorque() of this motor. Note: if driveline is not connected to outer 1D shafts, it should be GetInnerTorque2() = - GetInnerTorque1()

◆ Initialize() [1/3]

void chrono::ChLinkMotorRotationDriveline::Initialize ( std::shared_ptr< ChBodyFrame mbody1,
std::shared_ptr< ChBodyFrame mbody2,
bool  pos_are_relative,
ChFrame<>  mframe1,
ChFrame<>  mframe2 
)
overridevirtual

Specialized initialization for LinkMotorRotationDriveline, given the two bodies to be connected, the positions of the two frames to connect on the bodies (each expressed in body or abs.

coordinates).

Parameters
mbody1first body to link
mbody2second body to link
pos_are_relativetrue: following pos. are relative to bodies
mframe1slave frame 1 (rel. or abs.)
mframe2master frame 2 (rel. or abs.)

Reimplemented from chrono::ChLinkMateGeneric.

◆ Initialize() [2/3]

void chrono::ChLinkMotorRotationDriveline::Initialize ( std::shared_ptr< ChBodyFrame mbody1,
std::shared_ptr< ChBodyFrame mbody2,
bool  pos_are_relative,
ChVector<>  mpt1,
ChVector<>  mpt2,
ChVector<>  mnorm1,
ChVector<>  mnorm2 
)
overridevirtual

Specialized initialization for LinkMotorRotationDriveline based on passing two vectors (point + dir) on the two bodies, which will represent the X axes of the two frames (Y and Z will be built from the X vector via Gram Schmidt orthonormalization).

Parameters
mbody1first body to link
mbody2second body to link
pos_are_relativetrue: following pos. are relative to bodies
mpt1origin of slave frame 1 (rel. or abs.)
mpt2origin of master frame 2 (rel. or abs.)
mnorm1X axis of slave plane 1 (rel. or abs.)
mnorm2X axis of master plane 2 (rel. or abs.)

Reimplemented from chrono::ChLinkMateGeneric.

◆ Initialize() [3/3]

void chrono::ChLinkMotorRotationDriveline::Initialize ( std::shared_ptr< ChBodyFrame mbody1,
std::shared_ptr< ChBodyFrame mbody2,
ChFrame<>  mabsframe 
)
overridevirtual

Initialize the generic mate, given the two bodies to be connected, and the absolute position of the mate (the two frames to connect on the bodies will be initially coincindent to that frame).

Parameters
mbody1first body to link
mbody2second body to link
mabsframemate frame, in abs. coordinate

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntFromDescriptor()

void chrono::ChLinkMotorRotationDriveline::IntFromDescriptor ( const unsigned int  off_v,
ChStateDelta v,
const unsigned int  off_L,
ChVectorDynamic<> &  L 
)
overridevirtual

After a solver solution, fetch values from variables and constraints into vectors:

Parameters
off_voffset for v
vvector to where the q 'unknowns' term of the variables will be copied
off_Loffset for L
Lvector to where L 'lagrangian ' term of the constraints will be copied

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntLoadConstraint_C()

void chrono::ChLinkMotorRotationDriveline::IntLoadConstraint_C ( const unsigned int  off,
ChVectorDynamic<> &  Qc,
const double  c,
bool  do_clamp,
double  recovery_clamp 
)
overridevirtual

Takes the term C, scale and adds to Qc at given offset: Qc += c*C.

Parameters
offoffset in Qc residual
Qcresult: the Qc residual, Qc += c*C
ca scaling factor
do_clampapply clamping to c*C?
recovery_clampvalue for min/max clamping of c*C

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntLoadConstraint_Ct()

void chrono::ChLinkMotorRotationDriveline::IntLoadConstraint_Ct ( const unsigned int  off,
ChVectorDynamic<> &  Qc,
const double  c 
)
overridevirtual

Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct.

Parameters
offoffset in Qc residual
Qcresult: the Qc residual, Qc += c*Ct
ca scaling factor

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntLoadResidual_CqL()

void chrono::ChLinkMotorRotationDriveline::IntLoadResidual_CqL ( const unsigned int  off_L,
ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  L,
const double  c 
)
overridevirtual

Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.

Parameters
off_Loffset in L multipliers
Rresult: the R residual, R += c*Cq'*L
Lthe L vector
ca scaling factor

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntLoadResidual_F()

void chrono::ChLinkMotorRotationDriveline::IntLoadResidual_F ( const unsigned int  off,
ChVectorDynamic<> &  R,
const double  c 
)
overridevirtual

Takes the F force term, scale and adds to R at given offset: R += c*F.

Parameters
offoffset in R residual
Rresult: the R residual, R += c*F
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntLoadResidual_Mv()

void chrono::ChLinkMotorRotationDriveline::IntLoadResidual_Mv ( const unsigned int  off,
ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  w,
const double  c 
)
overridevirtual

Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w.

Parameters
offoffset in R residual
Rresult: the R residual, R += c*M*v
wthe w vector
ca scaling factor

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGather()

void chrono::ChLinkMotorRotationDriveline::IntStateGather ( const unsigned int  off_x,
ChState x,
const unsigned int  off_v,
ChStateDelta v,
double &  T 
)
overridevirtual

From item's state to global state vectors y={x,v} pasting the states at the specified offsets.

Parameters
off_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGatherAcceleration()

void chrono::ChLinkMotorRotationDriveline::IntStateGatherAcceleration ( const unsigned int  off_a,
ChStateDelta a 
)
overridevirtual

From item's state acceleration to global acceleration vector.

Parameters
off_aoffset in a accel. vector
aacceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateGatherReactions()

void chrono::ChLinkMotorRotationDriveline::IntStateGatherReactions ( const unsigned int  off_L,
ChVectorDynamic<> &  L 
)
overridevirtual

From item's reaction forces to global reaction vector.

Parameters
off_Loffset in L vector
LL vector of reaction forces

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntStateIncrement()

void chrono::ChLinkMotorRotationDriveline::IntStateIncrement ( const unsigned int  off_x,
ChState x_new,
const ChState x,
const unsigned int  off_v,
const ChStateDelta Dv 
)
overridevirtual

Computes x_new = x + Dt , using vectors at specified offsets.

By default, when DOF = DOF_w, it does just the sum, but in some cases (ex when using quaternions for rotations) it could do more complex stuff, and children classes might overload it.

Parameters
off_xoffset in x state vector
x_newstate vector, position part, incremented result
xstate vector, initial position part
off_voffset in v state vector
Dvstate vector, increment

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatter()

void chrono::ChLinkMotorRotationDriveline::IntStateScatter ( const unsigned int  off_x,
const ChState x,
const unsigned int  off_v,
const ChStateDelta v,
const double  T,
bool  full_update 
)
overridevirtual

From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets.

Parameters
off_xoffset in x state vector
xstate vector, position part
off_voffset in v state vector
vstate vector, speed part
Ttime
full_updateperform complete update

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatterAcceleration()

void chrono::ChLinkMotorRotationDriveline::IntStateScatterAcceleration ( const unsigned int  off_a,
const ChStateDelta a 
)
overridevirtual

From global acceleration vector to item's state acceleration.

Parameters
off_aoffset in a accel. vector
aacceleration part of state vector derivative

Reimplemented from chrono::ChPhysicsItem.

◆ IntStateScatterReactions()

void chrono::ChLinkMotorRotationDriveline::IntStateScatterReactions ( const unsigned int  off_L,
const ChVectorDynamic<> &  L 
)
overridevirtual

From global reaction vector to item's reaction forces.

Parameters
off_Loffset in L vector
LL vector of reaction forces

Reimplemented from chrono::ChLinkMateGeneric.

◆ IntToDescriptor()

void chrono::ChLinkMotorRotationDriveline::IntToDescriptor ( const unsigned int  off_v,
const ChStateDelta v,
const ChVectorDynamic<> &  R,
const unsigned int  off_L,
const ChVectorDynamic<> &  L,
const ChVectorDynamic<> &  Qc 
)
overridevirtual

Prepare variables and constraints to accommodate a solution:

Parameters
off_voffset for v and R
vvector that will be copied into the q 'unknowns' term of the variables (for warm starting)
Rvector that will be copied into the F 'force' term of the variables
off_Loffset for L and Qc
Lvector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting)
Qcvector that will be copied into the Qb 'constraint' term of the constraints

Reimplemented from chrono::ChLinkMateGeneric.

◆ VariablesFbIncrementMq()

void chrono::ChLinkMotorRotationDriveline::VariablesFbIncrementMq ( )
overridevirtual

Adds M*q (masses multiplied current 'qb') to Fb, ex.

if qb is initialized with v_old using VariablesQbLoadSpeed, this method can be used in timestepping schemes that do: M*v_new = M*v_old + forces*dt

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbIncrementPosition()

void chrono::ChLinkMotorRotationDriveline::VariablesQbIncrementPosition ( double  step)
overridevirtual

Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor.

pos+=qb*step If qb is a speed, this behaves like a single step of 1-st order numerical integration (Eulero integration).

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbLoadSpeed()

void chrono::ChLinkMotorRotationDriveline::VariablesQbLoadSpeed ( )
overridevirtual

Initialize the 'qb' part of the ChVariables with the current value of speeds.

Note: since 'qb' is the unknown, this function seems unnecessary, unless used before VariablesFbIncrementMq()

Reimplemented from chrono::ChPhysicsItem.

◆ VariablesQbSetSpeed()

void chrono::ChLinkMotorRotationDriveline::VariablesQbSetSpeed ( double  step = 0)
overridevirtual

Fetches the item speed (ex.

linear and angular vel.in rigid bodies) from the 'qb' part of the ChVariables and sets it as the current item speed. If 'step' is not 0, also should compute the approximate acceleration of the item using backward differences, that is accel=(new_speed-old_speed)/step. Mostly used after the solver provided the solution in ChVariables.

Reimplemented from chrono::ChPhysicsItem.


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/physics/ChLinkMotorRotationDriveline.h
  • /builds/uwsbel/chrono/src/chrono/physics/ChLinkMotorRotationDriveline.cpp