Description
A motor that enforces the angular speed w(t) between two ChShaft shafts, using a rheonomic constraint.
Note: no compliance is allowed, so if the actuator hits an undeformable obstacle it hits a pathological situation and the solver result can be unstable/unpredictable. Think at it as a servo drive with "infinitely stiff" control. This type of motor is very easy to use, stable and efficient, and should be used if the 'infinitely stiff' control assumption is a good approximation of what you simulate (ex very good and reactive controllers). By default it is initialized with constant angular speed: df/dt= 1 rad/s, use SetSpeedFunction() to change to other speed functions.
#include <ChShaftsMotorSpeed.h>
Public Member Functions | |
ChShaftsMotorSpeed (const ChShaftsMotorSpeed &other) | |
virtual ChShaftsMotorSpeed * | Clone () const override |
"Virtual" copy constructor (covariant return type). | |
void | SetSpeedFunction (const std::shared_ptr< ChFunction > mf) |
Sets the angular speed function w(t), in [rad/s]. More... | |
std::shared_ptr< ChFunction > | GetSpeedFunction () |
Gets the speed function w(t). In [rad/s]. | |
void | SetAngleOffset (double mo) |
Get initial offset, in [rad]. By default = 0. | |
double | GetAngleOffset () |
Get initial offset, in [rad]. | |
void | SetAvoidAngleDrift (bool mb) |
Set if the constraint must avoid angular drift. More... | |
bool | GetAvoidAngleDrift () |
Set if the constraint is in "avoid angle drift" mode. | |
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... | |
virtual double | GetMotorTorque () const override |
Get the current motor torque between shaft2 and shaft1, expressed as applied to shaft1. | |
virtual void | Update (double mytime, bool update_assets=true) override |
Update all auxiliary data. | |
virtual int | GetDOF () override |
Number of scalar constraints. | |
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) override |
From global state vectors y={x,v} to item's state (and update) fetching the states at the 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 | 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 | 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 | 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 | 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 | 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 | 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::ChShaftsMotorBase | |
ChShaftsMotorBase (const ChShaftsMotorBase &other) | |
virtual double | GetMotorRot () const |
Get the actual angle rotation [rad] of the motor, in terms of phase of shaft 1 respect to 2. | |
virtual double | GetMotorRot_dt () const |
Get the actual speed [rad/s] of the motor, in terms of speed of shaft 1 respect to 2. | |
virtual double | GetMotorRot_dtdt () const |
Get the actual acceleration [rad/s^2] of the motor, in terms of accel. of shaft 1 respect to 2. | |
virtual int | GetMotorRotTurns () const |
In case of multi-turns, gets the current actuator number of (integer) rotations: | |
virtual double | GetMotorRotPeriodic () const |
In case of multi-turns, gets the current actuator rotation angle [rad], in periodic -PI..+PI. | |
virtual double | GetTorqueReactionOn1 () const override |
Get the reaction torque exchanged between the two shafts, considered as applied to the 1st axis. | |
virtual double | GetTorqueReactionOn2 () const override |
Get the reaction torque exchanged between the two shafts, considered as applied to the 2nd axis. | |
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. | |
ChShaft * | GetShaft1 () |
Get the first (input) shaft. | |
ChShaft * | GetShaft2 () |
Get the second (output) shaft. | |
double | GetRelativeRotation () const |
Get the actual relative 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) | |
ChSystem * | GetSystem () 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< ChAsset > | GetAssetN (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, 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 | 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_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. | |
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 | 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 | VariablesQbIncrementPosition (double step) |
Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. 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 | 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 | |
Protected Attributes inherited from chrono::ChShaftsCouple | |
ChShaft * | shaft1 |
first shaft | |
ChShaft * | shaft2 |
second shaft | |
Protected Attributes inherited from chrono::ChPhysicsItem | |
ChSystem * | system |
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()
|
overridevirtual |
Method to allow deserialization of transient data from archives.
Method to allow de serialization of transient data from archives.
Reimplemented from chrono::ChShaftsMotorBase.
◆ ConstraintsFetch_react()
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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.
◆ Initialize()
|
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
-
mshaft1 first shaft to join (motor output shaft) mshaft2 second shaft to join (motor truss)
Reimplemented from chrono::ChShaftsCouple.
◆ IntFromDescriptor()
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overridevirtual |
After a solver solution, fetch values from variables and constraints into vectors:
- Parameters
-
off_v offset for v v vector to where the q 'unknowns' term of the variables will be copied off_L offset for L L vector to where L 'lagrangian ' term of the constraints will be copied
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadConstraint_C()
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overridevirtual |
Takes the term C, scale and adds to Qc at given offset: Qc += c*C.
- Parameters
-
off offset in Qc residual Qc result: the Qc residual, Qc += c*C c a scaling factor do_clamp apply clamping to c*C? recovery_clamp value for min/max clamping of c*C
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadConstraint_Ct()
|
overridevirtual |
Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct.
- Parameters
-
off offset in Qc residual Qc result: the Qc residual, Qc += c*Ct c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadResidual_CqL()
|
overridevirtual |
Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L.
- Parameters
-
off_L offset in L multipliers R result: the R residual, R += c*Cq'*L L the L vector c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadResidual_F()
|
overridevirtual |
Takes the F force term, scale and adds to R at given offset: R += c*F.
- Parameters
-
off offset in R residual R result: the R residual, R += c*F c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntLoadResidual_Mv()
|
overridevirtual |
Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w.
- Parameters
-
off offset in R residual R result: the R residual, R += c*M*v w the w vector c a scaling factor
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateGather()
|
overridevirtual |
From item's state to global state vectors y={x,v} pasting the states at the specified offsets.
- Parameters
-
off_x offset in x state vector x state vector, position part off_v offset in v state vector v state vector, speed part T time
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateGatherAcceleration()
|
overridevirtual |
From item's state acceleration to global acceleration vector.
- Parameters
-
off_a offset in a accel. vector a acceleration part of state vector derivative
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateGatherReactions()
|
overridevirtual |
From item's reaction forces to global reaction vector.
- Parameters
-
off_L offset in L vector L L vector of reaction forces
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateScatter()
|
overridevirtual |
From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets.
- Parameters
-
off_x offset in x state vector x state vector, position part off_v offset in v state vector v state vector, speed part T time
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateScatterAcceleration()
|
overridevirtual |
From global acceleration vector to item's state acceleration.
- Parameters
-
off_a offset in a accel. vector a acceleration part of state vector derivative
Reimplemented from chrono::ChPhysicsItem.
◆ IntStateScatterReactions()
|
overridevirtual |
From global reaction vector to item's reaction forces.
- Parameters
-
off_L offset in L vector L L vector of reaction forces
Reimplemented from chrono::ChPhysicsItem.
◆ IntToDescriptor()
|
overridevirtual |
Prepare variables and constraints to accommodate a solution:
- Parameters
-
off_v offset for v and R v vector that will be copied into the q 'unknowns' term of the variables (for warm starting) R vector that will be copied into the F 'force' term of the variables off_L offset for L and Qc L vector that will be copied into the L 'lagrangian ' term of the constraints (for warm starting) Qc vector that will be copied into the Qb 'constraint' term of the constraints
Reimplemented from chrono::ChPhysicsItem.
◆ SetAvoidAngleDrift()
|
inline |
Set if the constraint must avoid angular drift.
If true, it means that the constraint is satisfied also at the rotation level, by integrating the velocity in a separate auxiliary state. Default, true.
◆ SetSpeedFunction()
|
inline |
Sets the angular speed function w(t), in [rad/s].
It is a function of time. Best if C0 continuous, otherwise it gives peaks in accelerations.
◆ 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.
◆ 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()
|
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/ChShaftsMotorSpeed.h
- /builds/uwsbel/chrono/src/chrono/physics/ChShaftsMotorSpeed.cpp