A class that allows the sampling of IK constraints. More...

#include <default_constraint_samplers.h>

Inheritance diagram for constraint_samplers::IKConstraintSampler:

Collaboration diagram for constraint_samplers::IKConstraintSampler:

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Public Member Functions
	IKConstraintSampler (const planning_scene::PlanningSceneConstPtr &scene, const std::string &group_name)
	Constructor.

	IKConstraintSampler (const planning_scene::PlanningSceneConstPtr &scene, const std::string &group_name, unsigned int seed)
	Constructor.

bool	configure (const moveit_msgs::msg::Constraints &constr) override
	Configures the IK constraint given a constraints message.

bool	configure (const IKSamplingPose &sp)
	Configures the Constraint given a IKSamplingPose.

double	getIKTimeout () const
	Gets the timeout argument passed to the IK solver.

void	setIKTimeout (double timeout)
	Sets the timeout argument passed to the IK solver.

const kinematic_constraints::PositionConstraintPtr &	getPositionConstraint () const
	Gets the position constraint associated with this sampler.

const kinematic_constraints::OrientationConstraintPtr &	getOrientationConstraint () const
	Gets the orientation constraint associated with this sampler.

double	getSamplingVolume () const
	Gets the volume associated with the position and orientation constraints.

const std::string &	getLinkName () const
	Gets the link name associated with this sampler.

bool	sample (moveit::core::RobotState &state, const moveit::core::RobotState &reference_state, unsigned int max_attempts) override
	Produces an IK sample.

bool	samplePose (Eigen::Vector3d &pos, Eigen::Quaterniond &quat, const moveit::core::RobotState &ks, unsigned int max_attempts)
	Returns a pose that falls within the constraint regions.

const std::string &	getName () const override
	Get the name of the constraint sampler, for debugging purposes should be in CamelCase format.

Public Member Functions inherited from constraint_samplers::ConstraintSampler
	ConstraintSampler (const planning_scene::PlanningSceneConstPtr &scene, const std::string &group_name)
	Constructor.

virtual	~ConstraintSampler ()

const std::string &	getGroupName () const
	Gets the group name set in the constructor.

const moveit::core::JointModelGroup *	getJointModelGroup () const
	Gets the joint model group.

const planning_scene::PlanningSceneConstPtr &	getPlanningScene () const
	Gets the planning scene.

const std::vector< std::string > &	getFrameDependency () const
	Return the names of the mobile frames whose pose is needed when sample() is called.

const moveit::core::GroupStateValidityCallbackFn &	getGroupStateValidityCallback () const
	Gets the callback used to determine state validity during sampling. The sampler will attempt to satisfy this constraint if possible, but there is no guarantee.

void	setGroupStateValidityCallback (const moveit::core::GroupStateValidityCallbackFn &callback)
	Sets the callback used to determine the state validity during sampling. The sampler will attempt to satisfy this constraint if possible, but there is no guarantee.

bool	sample (moveit::core::RobotState &state)
	Samples given the constraints, populating state. The value DEFAULT_MAX_SAMPLING_ATTEMPTS will be passed in as the maximum number of attempts to make to take a sample.

bool	sample (moveit::core::RobotState &state, unsigned int max_attempts)
	Samples given the constraints, populating state. This function allows the parameter max_attempts to be set.

bool	sample (moveit::core::RobotState &state, const moveit::core::RobotState &reference_state)
	Samples given the constraints, populating state. The value DEFAULT_MAX_SAMPLING_ATTEMPTS will be passed in as the maximum number of attempts to make to take a sample.

bool	isValid () const
	Returns whether or not the constraint sampler is valid or not. To be valid, the joint model group must be available in the kinematic model and configure() must have successfully been called.

bool	getVerbose () const
	Check if the sampler is set to verbose mode.

virtual void	setVerbose (bool verbose)
	Enable/disable verbose mode for sampler.

Protected Member Functions
void	clear () override
	Clears all data from the constraint.

bool	loadIKSolver ()
	Performs checks and sets various internal values associated with the IK solver.

bool	callIK (const geometry_msgs::msg::Pose &ik_query, const kinematics::KinematicsBase::IKCallbackFn &adapted_ik_validity_callback, double timeout, moveit::core::RobotState &state, bool use_as_seed)
	Actually calls IK on the given pose, generating a random seed state.

bool	sampleHelper (moveit::core::RobotState &state, const moveit::core::RobotState &reference_state, unsigned int max_attempts)

bool	validate (moveit::core::RobotState &state) const

Protected Attributes
random_numbers::RandomNumberGenerator	random_number_generator_
	Random generator used by the sampler.

IKSamplingPose	sampling_pose_
	Holder for the pose used for sampling.

kinematics::KinematicsBaseConstPtr	kb_
	Holds the kinematics solver.

double	ik_timeout_
	Holds the timeout associated with IK.

std::string	ik_frame_
	Holds the base from of the IK solver.

bool	transform_ik_
	True if the frame associated with the kinematic model is different than the base frame of the IK solver.

bool	need_eef_to_ik_tip_transform_
	True if the tip frame of the inverse kinematic is different than the frame of the end effector.

Eigen::Isometry3d	eef_to_ik_tip_transform_
	Holds the transformation from end effector to IK tip frame.

Protected Attributes inherited from constraint_samplers::ConstraintSampler
bool	is_valid_
	Holds the value for validity.

planning_scene::PlanningSceneConstPtr	scene_
	Holds the planning scene.

const moveit::core::JointModelGroup *const	jmg_
	Holds the joint model group associated with this constraint.

std::vector< std::string >	frame_depends_
	Holds the set of frames that must exist in the reference state to allow samples to be drawn.

moveit::core::GroupStateValidityCallbackFn	group_state_validity_callback_
	Holds the callback for state validity.

bool	verbose_
	True if verbosity is on.

Additional Inherited Members
Static Public Attributes inherited from constraint_samplers::ConstraintSampler
static const unsigned int	DEFAULT_MAX_SAMPLING_ATTEMPTS = 2
	The default value associated with a sampling request. By default if a valid sample cannot be produced in this many attempts, it returns with no sample.

Detailed Description

A class that allows the sampling of IK constraints.

An IK constraint can have a position constraint, and orientation constraint, or both. The constraint will attempt to sample a pose that adheres to the constraint, and then solves IK for that pose.

Definition at line 312 of file default_constraint_samplers.h.

Constructor & Destructor Documentation

◆ IKConstraintSampler() [1/2]

constraint_samplers::IKConstraintSampler::IKConstraintSampler	(	const planning_scene::PlanningSceneConstPtr &	scene,
		const std::string &	group_name
	)

inline

Constructor.

Parameters

[in]	scene	The planning scene used to check the constraint
[in]	group_name	The group name associated with the constraint. Will be invalid if no group name is passed in or the joint model group cannot be found in the kinematic model

Definition at line 325 of file default_constraint_samplers.h.

◆ IKConstraintSampler() [2/2]

constraint_samplers::IKConstraintSampler::IKConstraintSampler	(	const planning_scene::PlanningSceneConstPtr &	scene,
		const std::string &	group_name,
		unsigned int	seed
	)

inline

Constructor.

Parameters

[in]	scene	The planning scene used to check the constraint
[in]	group_name	The group name associated with the constraint. Will be invalid if no group name is passed in or the joint model group cannot be found in the kinematic model
[in]	seed	The rng seed to be used

Definition at line 342 of file default_constraint_samplers.h.

Member Function Documentation

◆ callIK()

bool constraint_samplers::IKConstraintSampler::callIK	(	const geometry_msgs::msg::Pose &	ik_query,
		const kinematics::KinematicsBase::IKCallbackFn &	adapted_ik_validity_callback,
		double	timeout,
		moveit::core::RobotState &	state,
		bool	use_as_seed
	)

protected

Actually calls IK on the given pose, generating a random seed state.

Parameters

ik_query	The pose for solving IK, assumed to be for the tip frame in the base frame
timeout	The timeout for the IK search
jsg	The joint state group into which to place the solution
use_as_seed	If true, the state values in jsg are used as seed for the IK

Returns: True if IK returns successfully with the timeout, and otherwise false.

Definition at line 662 of file default_constraint_samplers.cpp.

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◆ clear()

void constraint_samplers::IKConstraintSampler::clear ( )

overrideprotectedvirtual

Clears all data from the constraint.

Reimplemented from constraint_samplers::ConstraintSampler.

Definition at line 243 of file default_constraint_samplers.cpp.

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◆ configure() [1/2]

bool constraint_samplers::IKConstraintSampler::configure ( const IKSamplingPose & sp )

Configures the Constraint given a IKSamplingPose.

This function performs the actual constraint configuration. It returns true if the following are true:

The IKSamplingPose has either a valid orientation or position constraint
The position and orientation constraints are specified for the same link

There is a valid IK solver instance for the indicated group. This will be only be the case if a group has a specific solver associated with it. For situations where the super-group doesn't have a solver, but all subgroups have solvers, then use the ConstraintSamplerManager.

The kinematic model has both the links associated with the IK solver's tip and base frames.

The link specified in the constraints is the tip link of the IK solver

Parameters

[in] sp The variable that contains the position and orientation constraints

Returns: True if all conditions are met and the group specified in the constructor is valid. Otherwise, false.

Definition at line 253 of file default_constraint_samplers.cpp.

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◆ configure() [2/2]

bool constraint_samplers::IKConstraintSampler::configure ( const moveit_msgs::msg::Constraints & constr )

overridevirtual

Configures the IK constraint given a constraints message.

If the constraints message contains both orientation constraints and positions constraints, the function iterates through each potential pair until it finds a pair of position orientation constraints that lead to valid configuration of kinematic constraints. It creates an IKSamplingPose from these and calls configure(const IKSamplingPose &sp). If no pair leads to both having valid configuration, it will attempt to iterate through the position constraints in the Constraints message, calling configure(const IKSamplingPose &sp) on the resulting IKSamplingPose. Finally, if no valid position constraints exist it will attempt the same procedure with the orientation constraints. If no valid position or orientation constraints exist, it will return false. For more information, see the docs for configure(const IKSamplingPose &sp).

Parameters

constr The Constraint message

Returns: True if some valid position and orientation constraints exist and the overloaded configuration function returns true. Otherwise, returns false.

Implements constraint_samplers::ConstraintSampler.

Definition at line 295 of file default_constraint_samplers.cpp.

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◆ getIKTimeout()

double constraint_samplers::IKConstraintSampler::getIKTimeout ( ) const

inline

Gets the timeout argument passed to the IK solver.

Returns: The IK timeout

Definition at line 406 of file default_constraint_samplers.h.

◆ getLinkName()

const std::string & constraint_samplers::IKConstraintSampler::getLinkName ( ) const

Gets the link name associated with this sampler.

Returns: The associated link name

Definition at line 355 of file default_constraint_samplers.cpp.

◆ getName()

const std::string & constraint_samplers::IKConstraintSampler::getName ( ) const

inlineoverridevirtual

Get the name of the constraint sampler, for debugging purposes should be in CamelCase format.

Returns: string of name

Implements constraint_samplers::ConstraintSampler.

Definition at line 519 of file default_constraint_samplers.h.

◆ getOrientationConstraint()

const kinematic_constraints::OrientationConstraintPtr & constraint_samplers::IKConstraintSampler::getOrientationConstraint ( ) const

inline

Gets the orientation constraint associated with this sampler.

Returns: The orientation constraint, or an empty shared_ptr if none has been specified

Definition at line 437 of file default_constraint_samplers.h.

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◆ getPositionConstraint()

const kinematic_constraints::PositionConstraintPtr & constraint_samplers::IKConstraintSampler::getPositionConstraint ( ) const

inline

Gets the position constraint associated with this sampler.

Returns: The position constraint, or an empty shared_ptr if none has been specified

Definition at line 427 of file default_constraint_samplers.h.

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◆ getSamplingVolume()

double constraint_samplers::IKConstraintSampler::getSamplingVolume ( ) const

Gets the volume associated with the position and orientation constraints.

This function computes the volume of the sampling constraint. The volume associated with the position constraint is either the product of the volume of all position constraint regions, or 1.0 otherwise. The volume associated with the orientation constraint is the product of all the axis tolerances, or 1.0 otherwise. If both are specified, the product of the volumes is returned.

Returns: Returns the sum of the volumes of all constraint regions associated with the position and orientation constraints.

Definition at line 332 of file default_constraint_samplers.cpp.

◆ loadIKSolver()

bool constraint_samplers::IKConstraintSampler::loadIKSolver ( )

protected

Performs checks and sets various internal values associated with the IK solver.

Returns: True if the IK solver exists and if it associated with the expected base frame and tip frames. Otherwise false.

Definition at line 362 of file default_constraint_samplers.cpp.

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◆ sample()

bool constraint_samplers::IKConstraintSampler::sample	(	moveit::core::RobotState &	state,
		const moveit::core::RobotState &	reference_state,
		unsigned int	max_attempts
	)

overridevirtual

Produces an IK sample.

This function first calls the samplePose function to produce a position and orientation in the constraint region. It then calls IK on that pose. If a pose that satisfies the constraints can be determined, and IK returns a solution for that pose, then the joint values associated with the joint group will be populated with the results of the IK, and the function will return true. The function will attempt to sample a pose up to max_attempts number of times, and then call IK on that value. If IK is not successful, it will repeat the pose sample and IK procedure max_attempt times. If in any iteration a valid pose cannot be sample within max_attempts time, it will return false.

Parameters

jsg	The joint state group in question. Must match the group passed in the constructor or will return false.
ks	A reference state that will be used for transforming the IK poses
max_attempts	The number of attempts to both sample and try IK

Returns: True if a valid sample pose was produced and valid IK found for that pose. Otherwise false.

Implements constraint_samplers::ConstraintSampler.

Definition at line 580 of file default_constraint_samplers.cpp.

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◆ sampleHelper()

bool constraint_samplers::IKConstraintSampler::sampleHelper	(	moveit::core::RobotState &	state,
		const moveit::core::RobotState &	reference_state,
		unsigned int	max_attempts
	)

protected

Definition at line 586 of file default_constraint_samplers.cpp.

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◆ samplePose()

bool constraint_samplers::IKConstraintSampler::samplePose	(	Eigen::Vector3d &	pos,
		Eigen::Quaterniond &	quat,
		const moveit::core::RobotState &	ks,
		unsigned int	max_attempts
	)

Returns a pose that falls within the constraint regions.

If a position constraint is specified, then a position is produced by selecting a random region among the constraint regions and taking a sample in that region. If no region is valid the function returns false. If no position constraint is specified, a position is produced by assigning a random valid value to each group joint, performing forward kinematics, and taking the resulting pose. If an orientation constraint is specified, then an quaternion is produced by sampling a difference value within the axis tolerances and applying the difference rotation to the orientation constraint target. Otherwise, a random quaternion is produced.

Parameters

[out]	pos	The position component of the sample
[out]	quat	The orientation component of the sample. It will always be a normalized quaternion.
[in]	ks	The reference state used for performing transforms
[in]	max_attempts	The maximum attempts to try to sample - applies only to the position constraint

Returns: True if a sample was successfully produced, otherwise false

Definition at line 441 of file default_constraint_samplers.cpp.

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◆ setIKTimeout()

void constraint_samplers::IKConstraintSampler::setIKTimeout ( double timeout )

inline

Sets the timeout argument passed to the IK solver.

Parameters

timeout The timeout argument that will be used in future IK calls

Definition at line 416 of file default_constraint_samplers.h.

◆ validate()

bool constraint_samplers::IKConstraintSampler::validate ( moveit::core::RobotState & state ) const

protected

Definition at line 653 of file default_constraint_samplers.cpp.

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Member Data Documentation

◆ eef_to_ik_tip_transform_

Eigen::Isometry3d constraint_samplers::IKConstraintSampler::eef_to_ik_tip_transform_

protected

Holds the transformation from end effector to IK tip frame.

Definition at line 562 of file default_constraint_samplers.h.

◆ ik_frame_

std::string constraint_samplers::IKConstraintSampler::ik_frame_

protected

Holds the base from of the IK solver.

Definition at line 557 of file default_constraint_samplers.h.

◆ ik_timeout_

double constraint_samplers::IKConstraintSampler::ik_timeout_

protected

Holds the timeout associated with IK.

Definition at line 556 of file default_constraint_samplers.h.

◆ kb_

kinematics::KinematicsBaseConstPtr constraint_samplers::IKConstraintSampler::kb_

protected

Holds the kinematics solver.

Definition at line 555 of file default_constraint_samplers.h.

◆ need_eef_to_ik_tip_transform_

bool constraint_samplers::IKConstraintSampler::need_eef_to_ik_tip_transform_

protected

True if the tip frame of the inverse kinematic is different than the frame of the end effector.

Definition at line 560 of file default_constraint_samplers.h.

◆ random_number_generator_

random_numbers::RandomNumberGenerator constraint_samplers::IKConstraintSampler::random_number_generator_

protected

Random generator used by the sampler.

Definition at line 553 of file default_constraint_samplers.h.

◆ sampling_pose_

IKSamplingPose constraint_samplers::IKConstraintSampler::sampling_pose_

protected

Holder for the pose used for sampling.

Definition at line 554 of file default_constraint_samplers.h.

◆ transform_ik_

bool constraint_samplers::IKConstraintSampler::transform_ik_

protected

True if the frame associated with the kinematic model is different than the base frame of the IK solver.

Definition at line 558 of file default_constraint_samplers.h.

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

moveit_core/constraint_samplers/include/moveit/constraint_samplers/default_constraint_samplers.h
moveit_core/constraint_samplers/src/default_constraint_samplers.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ IKConstraintSampler() [1/2]

◆ IKConstraintSampler() [2/2]

Member Function Documentation

◆ callIK()

◆ clear()

◆ configure() [1/2]

◆ configure() [2/2]

◆ getIKTimeout()

◆ getLinkName()

◆ getName()

◆ getOrientationConstraint()

◆ getPositionConstraint()

◆ getSamplingVolume()

◆ loadIKSolver()

◆ sample()

◆ sampleHelper()

◆ samplePose()

◆ setIKTimeout()

◆ validate()

Member Data Documentation

◆ eef_to_ik_tip_transform_

◆ ik_frame_

◆ ik_timeout_

◆ kb_

◆ need_eef_to_ik_tip_transform_

◆ random_number_generator_

◆ sampling_pose_

◆ transform_ik_