Drake
Drake C++ Documentation
QuaternionFloatingJoint< T > Class Template Referencefinal

Detailed Description

template<typename T>
class drake::multibody::QuaternionFloatingJoint< T >

This Joint allows two bodies to move freely relatively to one another.

That is, given a frame F attached to the parent body P and a frame M attached to the child body B (see the Joint class's documentation), this Joint allows frame M to translate and rotate freely with respect to F, introducing six degrees of freedom. This Joint introduces four generalized positions to describe the orientation R_FM of frame M in F with a quaternion q_FM, and three generalized positions to describe the translation of frame M's origin in F with a position vector p_FM. The seven entries of the configuration vector q are ordered (q_FM, p_FM) with the quaternion, ordered wxyz (scalar then vector), preceding the translation vector. As generalized velocities, this Joint introduces the angular velocity w_FM of frame M in F and the linear velocity v_FM of frame M's origin in frame F, ordered (w_FM, v_FM).

Template Parameters
TThe scalar type, which must be one of the default scalars.

#include <drake/multibody/tree/quaternion_floating_joint.h>

Public Member Functions

 QuaternionFloatingJoint (const std::string &name, const Frame< T > &frame_on_parent, const Frame< T > &frame_on_child, double angular_damping=0.0, double translational_damping=0.0)
 Constructor for a QuaternionFloatingJoint granting six degrees of freedom to an outboard frame M attached to the child body B with respect to an inboard frame F attached to the parent body P. More...
 
const std::string & type_name () const override
 Returns the name of this joint type: "quaternion_floating". More...
 
double default_angular_damping () const
 Returns this joint's default angular damping constant in N⋅m⋅s. More...
 
double default_translational_damping () const
 Returns this joint's default translational damping constant in N⋅s/m. More...
 
Does not allow copy, move, or assignment
 QuaternionFloatingJoint (const QuaternionFloatingJoint &)=delete
 
QuaternionFloatingJointoperator= (const QuaternionFloatingJoint &)=delete
 
 QuaternionFloatingJoint (QuaternionFloatingJoint &&)=delete
 
QuaternionFloatingJointoperator= (QuaternionFloatingJoint &&)=delete
 
Context-dependent value access
Quaternion< T > get_quaternion (const systems::Context< T > &context) const
 Gets the quaternion q_FM that represents the orientation of outboard frame M in the inboard frame F. More...
 
Vector3< T > get_translation (const systems::Context< T > &context) const
 Returns the position vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in inboard frame F. More...
 
Vector3< T > get_position (const systems::Context< T > &context) const
 (Deprecated.) More...
 
math::RigidTransform< T > GetPose (const systems::Context< T > &context) const
 Returns the pose X_FM of the outboard frame M as measured and expressed in the inboard frame F. More...
 
math::RigidTransform< T > get_pose (const systems::Context< T > &context) const
 (Deprecated.) More...
 
Vector3< T > get_angular_velocity (const systems::Context< T > &context) const
 Retrieves from context the angular velocity w_FM of the child frame M in the parent frame F, expressed in F. More...
 
Vector3< T > get_translational_velocity (const systems::Context< T > &context) const
 Retrieves from context the translational velocity v_FM of the child frame M's origin as measured and expressed in the parent frame F. More...
 
Context-dependent value setters
const QuaternionFloatingJoint< T > & SetQuaternion (systems::Context< T > *context, const Quaternion< T > &q_FM) const
 Sets context so that the orientation of frame M in F is given by the input quaternion q_FM. More...
 
const QuaternionFloatingJoint< T > & set_quaternion (systems::Context< T > *context, const Quaternion< T > &q_FM) const
 (Deprecated.) More...
 
const QuaternionFloatingJoint< T > & SetOrientation (systems::Context< T > *context, const math::RotationMatrix< T > &R_FM) const
 Sets the quaternion in context so this joint's orientation is consistent with the given R_FM rotation matrix. More...
 
const QuaternionFloatingJoint< T > & SetFromRotationMatrix (systems::Context< T > *context, const math::RotationMatrix< T > &R_FM) const
 (Deprecated.) More...
 
const QuaternionFloatingJoint< T > & SetTranslation (systems::Context< T > *context, const Vector3< T > &p_FM) const
 For this joint, stores the position vector p_FM in context. More...
 
const QuaternionFloatingJoint< T > & set_position (systems::Context< T > *context, const Vector3< T > &p_FM) const
 (Deprecated.) More...
 
const QuaternionFloatingJoint< T > & SetPose (systems::Context< T > *context, const math::RigidTransform< T > &X_FM) const
 Sets context to store X_FM the pose of frame M measured and expressed in frame F. More...
 
const QuaternionFloatingJoint< T > & set_pose (systems::Context< T > *context, const math::RigidTransform< T > &X_FM) const
 (Deprecated.) More...
 
const QuaternionFloatingJoint< T > & set_angular_velocity (systems::Context< T > *context, const Vector3< T > &w_FM) const
 Sets in context the state for this joint so that the angular velocity of the child frame M in the parent frame F is w_FM. More...
 
const QuaternionFloatingJoint< T > & set_translational_velocity (systems::Context< T > *context, const Vector3< T > &v_FM) const
 Sets in context the state for this joint so that the translational velocity of the child frame M's origin in the parent frame F is v_FM. More...
 
Random distribution setters
void set_random_translation_distribution (const Vector3< symbolic::Expression > &p_FM)
 For this joint, sets the random distribution that the translation of this joint will be randomly sampled from. More...
 
void set_random_position_distribution (const Vector3< symbolic::Expression > &p_FM)
 (Deprecated.) More...
 
void set_random_quaternion_distribution (const Eigen::Quaternion< symbolic::Expression > &q_FM)
 (Advanced) Sets the random distribution that the orientation of this joint will be randomly sampled from. More...
 
void set_random_quaternion_distribution_to_uniform ()
 Sets the random distribution such that the orientation of this joint will be randomly sampled using uniformly sampled rotations. More...
 
Default value getters
Quaternion< doubleget_default_quaternion () const
 Gets the default quaternion q_FM for this joint. More...
 
Vector3< doubleget_default_translation () const
 Returns this joint's default translation as the position vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in inboard frame F. More...
 
Vector3< doubleget_default_position () const
 (Deprecated.) More...
 
math::RigidTransform< doubleget_default_pose () const
 (Deprecated.) More...
 
Default value setters
void set_default_quaternion (const Quaternion< double > &q_FM)
 Sets the default quaternion q_FM of this joint. More...
 
void set_default_translation (const Vector3< double > &p_FM)
 Sets this joint's default position vector p_FM. More...
 
void set_default_position (const Vector3< double > &p_FM)
 (Deprecated.) More...
 
- Public Member Functions inherited from Joint< T >
 Joint (const std::string &name, const Frame< T > &frame_on_parent, const Frame< T > &frame_on_child, VectorX< double > damping, const VectorX< double > &pos_lower_limits, const VectorX< double > &pos_upper_limits, const VectorX< double > &vel_lower_limits, const VectorX< double > &vel_upper_limits, const VectorX< double > &acc_lower_limits, const VectorX< double > &acc_upper_limits)
 Creates a joint between two Frame objects which imposes a given kinematic relation between frame F attached on the parent body P and frame M attached on the child body B. More...
 
 Joint (const std::string &name, const Frame< T > &frame_on_parent, const Frame< T > &frame_on_child, const VectorX< double > &pos_lower_limits, const VectorX< double > &pos_upper_limits, const VectorX< double > &vel_lower_limits, const VectorX< double > &vel_upper_limits, const VectorX< double > &acc_lower_limits, const VectorX< double > &acc_upper_limits)
 Additional constructor overload for joints with zero damping. More...
 
virtual ~Joint ()
 
JointIndex index () const
 Returns this element's unique index. More...
 
int ordinal () const
 Returns this element's unique ordinal. More...
 
const std::string & name () const
 Returns the name of this joint. More...
 
const RigidBody< T > & parent_body () const
 Returns a const reference to the parent body P. More...
 
const RigidBody< T > & child_body () const
 Returns a const reference to the child body B. More...
 
const Frame< T > & frame_on_parent () const
 Returns a const reference to the frame F attached on the parent body P. More...
 
const Frame< T > & frame_on_child () const
 Returns a const reference to the frame M attached on the child body B. More...
 
int velocity_start () const
 Returns the index to the first generalized velocity for this joint within the vector v of generalized velocities for the full multibody system. More...
 
int num_velocities () const
 Returns the number of generalized velocities describing this joint. More...
 
int position_start () const
 Returns the index to the first generalized position for this joint within the vector q of generalized positions for the full multibody system. More...
 
int num_positions () const
 Returns the number of generalized positions describing this joint. More...
 
bool can_rotate () const
 Returns true if this joint's mobility allows relative rotation of the two frames associated with this joint. More...
 
bool can_translate () const
 Returns true if this joint's mobility allows relative translation of the two frames associated with this joint. More...
 
std::string position_suffix (int position_index_in_joint) const
 Returns a string suffix (e.g. More...
 
std::string velocity_suffix (int velocity_index_in_joint) const
 Returns a string suffix (e.g. More...
 
const T & GetOnePosition (const systems::Context< T > &context) const
 Returns the position coordinate for joints with a single degree of freedom. More...
 
const T & GetOneVelocity (const systems::Context< T > &context) const
 Returns the velocity coordinate for joints with a single degree of freedom. More...
 
void AddInOneForce (const systems::Context< T > &context, int joint_dof, const T &joint_tau, MultibodyForces< T > *forces) const
 Adds into forces a force along the one of the joint's degrees of freedom indicated by index joint_dof. More...
 
void AddInDamping (const systems::Context< T > &context, MultibodyForces< T > *forces) const
 Adds into forces the force due to damping within this joint. More...
 
void Lock (systems::Context< T > *context) const
 Lock the joint. More...
 
void Unlock (systems::Context< T > *context) const
 Unlock the joint. More...
 
bool is_locked (const systems::Context< T > &context) const
 
const VectorX< double > & default_damping_vector () const
 Returns all default damping coefficients for joints that model viscous damping, of size num_velocities(). More...
 
const VectorX< T > & GetDampingVector (const systems::Context< T > &context) const
 Returns the Context dependent damping coefficients stored as parameters in context. More...
 
void set_default_damping_vector (const VectorX< double > &damping)
 Sets the default value of the viscous damping coefficients for this joint. More...
 
void SetDampingVector (systems::Context< T > *context, const VectorX< T > &damping) const
 Sets the value of the viscous damping coefficients for this joint, stored as parameters in context. More...
 
 Joint (const Joint &)=delete
 
Jointoperator= (const Joint &)=delete
 
 Joint (Joint &&)=delete
 
Jointoperator= (Joint &&)=delete
 
const VectorX< double > & position_lower_limits () const
 
const VectorX< double > & position_upper_limits () const
 Returns the position upper limits. More...
 
const VectorX< double > & velocity_lower_limits () const
 Returns the velocity lower limits. More...
 
const VectorX< double > & velocity_upper_limits () const
 Returns the velocity upper limits. More...
 
const VectorX< double > & acceleration_lower_limits () const
 Returns the acceleration lower limits. More...
 
const VectorX< double > & acceleration_upper_limits () const
 Returns the acceleration upper limits. More...
 
const VectorX< double > & default_positions () const
 Returns the default positions. More...
 
void set_position_limits (const VectorX< double > &lower_limits, const VectorX< double > &upper_limits)
 Sets the position limits to lower_limits and upper_limits. More...
 
void set_velocity_limits (const VectorX< double > &lower_limits, const VectorX< double > &upper_limits)
 Sets the velocity limits to lower_limits and upper_limits. More...
 
void set_acceleration_limits (const VectorX< double > &lower_limits, const VectorX< double > &upper_limits)
 Sets the acceleration limits to lower_limits and upper_limits. More...
 
void set_default_positions (const VectorX< double > &default_positions)
 Sets the default positions to default_positions. More...
 
void SetDefaultPose (const math::RigidTransform< double > &X_FM)
 Sets this Joint's default generalized positions q₀ such that the pose of the child frame M in the parent frame F best matches the given pose. More...
 
math::RigidTransform< doubleGetDefaultPose () const
 Returns this Joint's default pose as a RigidTransform X_FM. More...
 
void SetDefaultPosePair (const Quaternion< double > &q_FM, const Vector3< double > &p_FM)
 (Advanced) This is the same as SetDefaultPose() except it takes the pose as a (quaternion, translation vector) pair. More...
 
std::pair< Eigen::Quaternion< double >, Vector3< double > > GetDefaultPosePair () const
 (Advanced) This is the same as GetDefaultPose() except it returns this Joint's default pose as a (quaternion, translation vector) pair. More...
 
- Public Member Functions inherited from MultibodyElement< T >
virtual ~MultibodyElement ()
 
ModelInstanceIndex model_instance () const
 Returns the ModelInstanceIndex of the model instance to which this element belongs. More...
 
template<typename MultibodyPlantDeferred = MultibodyPlant<T>>
const MultibodyPlantDeferred & GetParentPlant () const
 Returns the MultibodyPlant that owns this MultibodyElement. More...
 
void DeclareParameters (internal::MultibodyTreeSystem< T > *tree_system)
 Declares MultibodyTreeSystem Parameters at MultibodyTreeSystem::Finalize() time. More...
 
void SetDefaultParameters (systems::Parameters< T > *parameters) const
 Sets default values of parameters belonging to each MultibodyElement in parameters at a call to MultibodyTreeSystem::SetDefaultParameters(). More...
 
 MultibodyElement (const MultibodyElement &)=delete
 
MultibodyElementoperator= (const MultibodyElement &)=delete
 
 MultibodyElement (MultibodyElement &&)=delete
 
MultibodyElementoperator= (MultibodyElement &&)=delete
 

Static Public Attributes

static const char kTypeName [] = "quaternion_floating"
 The name for this Joint type. It resolves to "quaternion_floating". More...
 

Protected Member Functions

void DoAddInOneForce (const systems::Context< T > &, int, const T &, MultibodyForces< T > *) const override
 Joint<T> override called through public NVI, Joint::AddInForce(). More...
 
void DoAddInDamping (const systems::Context< T > &context, MultibodyForces< T > *forces) const override
 Joint<T> override called through public NVI, Joint::AddInDamping(). More...
 
- Protected Member Functions inherited from Joint< T >
virtual const T & DoGetOnePosition (const systems::Context< T > &) const
 Implementation of the NVI GetOnePosition() that must only be implemented by those joint subclasses that have a single degree of freedom. More...
 
virtual const T & DoGetOneVelocity (const systems::Context< T > &) const
 Implementation of the NVI GetOneVelocity() that must only be implemented by those joint subclasses that have a single degree of freedom. More...
 
void DoSetTopology (const internal::MultibodyTreeTopology &) override
 Implementation of the NVI SetTopology(). More...
 
const JointImplementationget_implementation () const
 Returns a const reference to the internal implementation of this joint. More...
 
bool has_implementation () const
 Returns whether this joint owns a particular implementation. More...
 
- Protected Member Functions inherited from MultibodyElement< T >
 MultibodyElement ()
 Default constructor made protected so that sub-classes can still declare their default constructors if they need to. More...
 
 MultibodyElement (ModelInstanceIndex model_instance)
 Constructor which allows specifying a model instance. More...
 
 MultibodyElement (ModelInstanceIndex model_instance, int64_t index)
 Both the model instance and element index are specified. More...
 
template<typename ElementIndexType >
ElementIndexType index_impl () const
 Returns this element's unique index. More...
 
int ordinal_impl () const
 Returns this element's unique ordinal. More...
 
const internal::MultibodyTree< T > & get_parent_tree () const
 Returns a constant reference to the parent MultibodyTree that owns this element. More...
 
const internal::MultibodyTreeSystem< T > & GetParentTreeSystem () const
 Returns a constant reference to the parent MultibodyTreeSystem that owns the parent MultibodyTree that owns this element. More...
 
void SetTopology (const internal::MultibodyTreeTopology &tree)
 Gives MultibodyElement-derived objects the opportunity to retrieve their topology after MultibodyTree::Finalize() is invoked. More...
 
systems::NumericParameterIndex DeclareNumericParameter (internal::MultibodyTreeSystem< T > *tree_system, const systems::BasicVector< T > &model_vector)
 To be used by MultibodyElement-derived objects when declaring parameters in their implementation of DoDeclareParameters(). More...
 
systems::AbstractParameterIndex DeclareAbstractParameter (internal::MultibodyTreeSystem< T > *tree_system, const AbstractValue &model_value)
 To be used by MultibodyElement-derived objects when declaring parameters in their implementation of DoDeclareParameters(). More...
 

Friends

template<typename >
class QuaternionFloatingJoint
 

Constructor & Destructor Documentation

◆ QuaternionFloatingJoint() [1/3]

◆ QuaternionFloatingJoint() [2/3]

◆ QuaternionFloatingJoint() [3/3]

QuaternionFloatingJoint ( const std::string &  name,
const Frame< T > &  frame_on_parent,
const Frame< T > &  frame_on_child,
double  angular_damping = 0.0,
double  translational_damping = 0.0 
)

Constructor for a QuaternionFloatingJoint granting six degrees of freedom to an outboard frame M attached to the child body B with respect to an inboard frame F attached to the parent body P.

The orientation of frame M in F is represented by a quaternion q_FM while the position of F in M is given by a position vector p_FM expressed in frame F. See this class's documentation for further details on the definition of these frames, get_quaternion() and get_translation() for an explanation of the configuration of this joint, and get_angular_velocity() and get_translational_velocity() for an explanation of the generalized velocities.

This constructor signature creates a joint with no joint limits, i.e. the joint position, velocity and acceleration limits are the pair (-∞, ∞). These can be set using the Joint methods set_position_limits(), set_velocity_limits() and set_acceleration_limits().

The first three arguments to this constructor are those of the Joint class constructor. See the Joint class's documentation for details. The additional parameters are:

Parameters
[in]angular_dampingViscous damping coefficient in N⋅m⋅s for the angular component of this joint's velocity, used to model losses within the joint. See documentation of default_angular_damping() for details on modelling of the damping force.
[in]translational_dampingViscous damping coefficient in N⋅s/m for the translational component of this joint's velocity, used to model losses within the joint. See documentation of default_translational_damping() for details on modelling of the damping force.
Exceptions
std::exceptionif angular_damping is negative.
std::exceptionif translational_damping is negative.

Member Function Documentation

◆ default_angular_damping()

double default_angular_damping ( ) const

Returns this joint's default angular damping constant in N⋅m⋅s.

The damping torque (in N⋅m) is modeled as τ = -damping⋅ω, i.e. opposing motion, with ω the angular velocity of frame M in F (see get_angular_velocity()) and τ the torque on child body B (to which M is rigidly attached).

◆ default_translational_damping()

double default_translational_damping ( ) const

Returns this joint's default translational damping constant in N⋅s/m.

The damping force (in N) is modeled as f = -damping⋅v i.e. opposing motion, with v the translational velocity of frame M in F (see get_translational_velocity()) and f the force on child body B at Mo.

◆ DoAddInDamping()

void DoAddInDamping ( const systems::Context< T > &  context,
MultibodyForces< T > *  forces 
) const
overrideprotectedvirtual

Joint<T> override called through public NVI, Joint::AddInDamping().

Therefore arguments were already checked to be valid. This method adds into the translational component of forces for this joint a dissipative force according to the viscous law f = -d⋅v, with d the damping coefficient (see default_translational_damping()). This method also adds into the angular component of forces for this joint a dissipative torque according to the viscous law τ = -d⋅ω, with d the damping coefficient (see default_angular_damping()).

Reimplemented from Joint< T >.

◆ DoAddInOneForce()

void DoAddInOneForce ( const systems::Context< T > &  ,
int  ,
const T &  ,
MultibodyForces< T > *   
) const
overrideprotectedvirtual

Joint<T> override called through public NVI, Joint::AddInForce().

Adding forces per-dof makes no physical sense. Therefore, this method throws an exception if invoked.

Implements Joint< T >.

◆ get_angular_velocity()

Vector3<T> get_angular_velocity ( const systems::Context< T > &  context) const

Retrieves from context the angular velocity w_FM of the child frame M in the parent frame F, expressed in F.

Parameters
[in]contextA Context for the MultibodyPlant this joint belongs to.
Return values
w_FMA vector in ℝ³ with the angular velocity of the child frame M in the parent frame F, expressed in F. Refer to this class's documentation for further details and definitions of these frames.

◆ get_default_pose()

math::RigidTransform<double> get_default_pose ( ) const

(Deprecated.)

Deprecated:
Removed since functionality already provided by base class Joint::GetDefaultPose()
This will be removed from Drake on or after 2024-08-01.

◆ get_default_position()

Vector3<double> get_default_position ( ) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::get_default_translation()
This will be removed from Drake on or after 2024-08-01.

◆ get_default_quaternion()

Quaternion<double> get_default_quaternion ( ) const

Gets the default quaternion q_FM for this joint.

Returns
The default quaternion q_FM of this.

◆ get_default_translation()

Vector3<double> get_default_translation ( ) const

Returns this joint's default translation as the position vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in inboard frame F.

Return values
Thisjoint's default translation as the position vector p_FM.

◆ get_pose()

math::RigidTransform<T> get_pose ( const systems::Context< T > &  context) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::GetPose()
This will be removed from Drake on or after 2024-08-01.

◆ get_position()

Vector3<T> get_position ( const systems::Context< T > &  context) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::get_translation()
This will be removed from Drake on or after 2024-08-01.

◆ get_quaternion()

Quaternion<T> get_quaternion ( const systems::Context< T > &  context) const

Gets the quaternion q_FM that represents the orientation of outboard frame M in the inboard frame F.

Refer to the documentation for this class for details.

Parameters
[in]contextA Context for the MultibodyPlant this joint belongs to.
Return values
q_FMThe quaternion representing the orientation of frame M in F.

◆ get_translation()

Vector3<T> get_translation ( const systems::Context< T > &  context) const

Returns the position vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in inboard frame F.

Parameters
[in]contextcontains the state of the multibody system.
Note
Class documentation describes inboard frame F and outboard frame M.
Return values
p_FMThe position vector from Fo (frame F's origin) to Mo (frame M's origin), expressed in frame F.

◆ get_translational_velocity()

Vector3<T> get_translational_velocity ( const systems::Context< T > &  context) const

Retrieves from context the translational velocity v_FM of the child frame M's origin as measured and expressed in the parent frame F.

Parameters
[in]contextA Context for the MultibodyPlant this joint belongs to.
Return values
v_FMA vector in ℝ³ with the translational velocity of the origin of child frame M in the parent frame F, expressed in F. Refer to this class's documentation for further details and definitions of these frames.

◆ GetPose()

math::RigidTransform<T> GetPose ( const systems::Context< T > &  context) const

Returns the pose X_FM of the outboard frame M as measured and expressed in the inboard frame F.

Refer to the documentation for this class for details.

Parameters
[in]contextA Context for the MultibodyPlant this joint belongs to.
Return values
X_FMThe pose of frame M in frame F.

◆ operator=() [1/2]

QuaternionFloatingJoint& operator= ( QuaternionFloatingJoint< T > &&  )
delete

◆ operator=() [2/2]

QuaternionFloatingJoint& operator= ( const QuaternionFloatingJoint< T > &  )
delete

◆ set_angular_velocity()

const QuaternionFloatingJoint<T>& set_angular_velocity ( systems::Context< T > *  context,
const Vector3< T > &  w_FM 
) const

Sets in context the state for this joint so that the angular velocity of the child frame M in the parent frame F is w_FM.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]w_FMA vector in ℝ³ with the angular velocity of the child frame M in the parent frame F, expressed in F. Refer to this class's documentation for further details and definitions of these frames.
Returns
a constant reference to this joint.

◆ set_default_position()

void set_default_position ( const Vector3< double > &  p_FM)

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::set_default_translation()
This will be removed from Drake on or after 2024-08-01.

◆ set_default_quaternion()

void set_default_quaternion ( const Quaternion< double > &  q_FM)

Sets the default quaternion q_FM of this joint.

Parameters
[in]q_FMThe desired default quaternion of the joint.

◆ set_default_translation()

void set_default_translation ( const Vector3< double > &  p_FM)

Sets this joint's default position vector p_FM.

Parameters
[in]p_FMposition vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in frame F.

◆ set_pose()

const QuaternionFloatingJoint<T>& set_pose ( systems::Context< T > *  context,
const math::RigidTransform< T > &  X_FM 
) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::SetPose()
This will be removed from Drake on or after 2024-08-01.

◆ set_position()

const QuaternionFloatingJoint<T>& set_position ( systems::Context< T > *  context,
const Vector3< T > &  p_FM 
) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::SetTranslation()
This will be removed from Drake on or after 2024-08-01.

◆ set_quaternion()

const QuaternionFloatingJoint<T>& set_quaternion ( systems::Context< T > *  context,
const Quaternion< T > &  q_FM 
) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::SetQuaternion()
This will be removed from Drake on or after 2024-08-01.

◆ set_random_position_distribution()

void set_random_position_distribution ( const Vector3< symbolic::Expression > &  p_FM)

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::set_random_translation_distribution()
This will be removed from Drake on or after 2024-08-01.

◆ set_random_quaternion_distribution()

void set_random_quaternion_distribution ( const Eigen::Quaternion< symbolic::Expression > &  q_FM)

(Advanced) Sets the random distribution that the orientation of this joint will be randomly sampled from.

If a translation (position) distribution has already been set with stochastic variables, it will remain so. Otherwise translation will be set to this joint's zero configuration. See get_quaternion() for details on the orientation representation.

Note
Use caution when setting a quaternion distribution. A naive uniform sampling of each component will not lead to a uniform sampling of the unit sphere. See set_random_quaternion_distribution_to_uniform() for the most common case of uniformly sampling rotations.

◆ set_random_quaternion_distribution_to_uniform()

void set_random_quaternion_distribution_to_uniform ( )

Sets the random distribution such that the orientation of this joint will be randomly sampled using uniformly sampled rotations.

◆ set_random_translation_distribution()

void set_random_translation_distribution ( const Vector3< symbolic::Expression > &  p_FM)

For this joint, sets the random distribution that the translation of this joint will be randomly sampled from.

If a quaternion distribution has already been set with stochastic variables, it will remain so. Otherwise the quaternion will be set to this joint's zero orientation. See get_translation() for details on the translation representation.

◆ set_translational_velocity()

const QuaternionFloatingJoint<T>& set_translational_velocity ( systems::Context< T > *  context,
const Vector3< T > &  v_FM 
) const

Sets in context the state for this joint so that the translational velocity of the child frame M's origin in the parent frame F is v_FM.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]w_FMA vector in ℝ³ with the translational velocity of the child frame M's origin in the parent frame F, expressed in F. Refer to this class's documentation for further details and definitions of these frames.
Returns
a constant reference to this joint.

◆ SetFromRotationMatrix()

const QuaternionFloatingJoint<T>& SetFromRotationMatrix ( systems::Context< T > *  context,
const math::RotationMatrix< T > &  R_FM 
) const

(Deprecated.)

Deprecated:
Use QuaternionFloatingJoint::SetOrientation()
This will be removed from Drake on or after 2024-08-01.

◆ SetOrientation()

const QuaternionFloatingJoint<T>& SetOrientation ( systems::Context< T > *  context,
const math::RotationMatrix< T > &  R_FM 
) const

Sets the quaternion in context so this joint's orientation is consistent with the given R_FM rotation matrix.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]R_FMThe rotation matrix relating the orientation of frame F and frame M.
Returns
a constant reference to this joint.

◆ SetPose()

const QuaternionFloatingJoint<T>& SetPose ( systems::Context< T > *  context,
const math::RigidTransform< T > &  X_FM 
) const

Sets context to store X_FM the pose of frame M measured and expressed in frame F.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]X_FMThe desired pose of frame M in frame F to be stored in context.
Returns
a constant reference to this joint.

◆ SetQuaternion()

const QuaternionFloatingJoint<T>& SetQuaternion ( systems::Context< T > *  context,
const Quaternion< T > &  q_FM 
) const

Sets context so that the orientation of frame M in F is given by the input quaternion q_FM.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]q_FMQuaternion relating frames F and M to be stored in context.
Returns
a constant reference to this joint.

◆ SetTranslation()

const QuaternionFloatingJoint<T>& SetTranslation ( systems::Context< T > *  context,
const Vector3< T > &  p_FM 
) const

For this joint, stores the position vector p_FM in context.

Parameters
[in,out]contextA Context for the MultibodyPlant this joint belongs to.
[in]p_FMposition vector p_FoMo_F from Fo (inboard frame F's origin) to Mo (outboard frame M's origin), expressed in frame F.
Returns
a constant reference to this joint.

◆ type_name()

const std::string& type_name ( ) const
overridevirtual

Returns the name of this joint type: "quaternion_floating".

Implements Joint< T >.

Friends And Related Function Documentation

◆ QuaternionFloatingJoint

friend class QuaternionFloatingJoint
friend

Member Data Documentation

◆ kTypeName

const char kTypeName = "quaternion_floating"
static

The name for this Joint type. It resolves to "quaternion_floating".


The documentation for this class was generated from the following file: