Represents a chain or tree of robot elements (rigid bodies and joints). More...

#include <robot_model.hpp>

Public Types
enum	ActuatorType { ActuatorType::X5_1, ActuatorType::X5_4, ActuatorType::X5_9, ActuatorType::X8_3, ActuatorType::X8_9, ActuatorType::X8_16 }

enum	BracketType { BracketType::X5LightLeft, BracketType::X5LightRight, BracketType::X5HeavyLeftInside, BracketType::X5HeavyLeftOutside, BracketType::X5HeavyRightInside, BracketType::X5HeavyRightOutside }

enum	LinkType { LinkType::X5 }

Public Member Functions
bool	addActuator (ActuatorType actuator_type)
	Add an element to the robot model with the kinematics/dynamics of an X5 actuator. More...

bool	addBracket (BracketType bracket_type)
	Add an element to the robot model with the kinematics/dynamics of a bracket between two actuators. More...

bool	addJoint (HebiJointType joint_type, bool combine)
	Adds a degree of freedom about the specified axis. More...

bool	addLink (LinkType link_type, double extension, double twist)
	Add an element to the robot model with the kinematics/dynamics of a link between two actuators. More...

bool	addRigidBody (const Eigen::Matrix4d &com, const Eigen::VectorXd &inertia, double mass, const Eigen::Matrix4d &output, bool combine)
	Adds a rigid body with the specified properties to the robot model. More...

Eigen::Matrix4d	getBaseFrame () const
	Returns the transform from the world coordinate system to the root kinematic body, as set by the setBaseFrame function. More...

size_t	getDoFCount () const
	Returns the number of settable degrees of freedom in the kinematic tree. (This is equal to the number of actuators added). More...

void	getEndEffector (const Eigen::VectorXd &positions, Eigen::Matrix4d &transform) const
	Generates the forward kinematics to the end effector (leaf node) frame(s). More...

void	getFK (HebiFrameType, const Eigen::VectorXd &positions, Matrix4dVector &frames) const
	Generates the forward kinematics for the given robot model. More...

void	getForwardKinematics (HebiFrameType, const Eigen::VectorXd &positions, Matrix4dVector &frames) const
	Generates the forward kinematics for the given robot model. More...

size_t	getFrameCount (HebiFrameType frame_type) const
	Return the number of frames in the forward kinematics. More...

void	getJ (HebiFrameType, const Eigen::VectorXd &positions, MatrixXdVector &jacobians) const
	Generates the Jacobian for each frame in the given kinematic tree. More...

void	getJacobianEndEffector (const Eigen::VectorXd &positions, Eigen::MatrixXd &jacobian) const
	Generates the Jacobian for the end effector (leaf node) frames(s). More...

void	getJacobians (HebiFrameType, const Eigen::VectorXd &positions, MatrixXdVector &jacobians) const
	Generates the Jacobian for each frame in the given kinematic tree. More...

void	getJEndEffector (const Eigen::VectorXd &positions, Eigen::MatrixXd &jacobian) const
	Generates the Jacobian for the end effector (leaf node) frames(s). More...

void	getMasses (Eigen::VectorXd &masses) const
	Returns the mass of each rigid body (or combination of rigid bodies) in the robot model. More...

	RobotModel ()
	Creates a robot model object with no bodies and an identity base frame. More...

void	setBaseFrame (const Eigen::Matrix4d &base_frame)
	Set the transform from a world coordinate system to the input of the root element in this robot model object. Defaults to an identity 4x4 matrix. More...

template<typename... Args>
IKResult	solveIK (const Eigen::VectorXd &initial_positions, Eigen::VectorXd &result, Args...objectives) const
	Solves for an inverse kinematics solution given a set of objectives. More...

template<typename... Args>
IKResult	solveInverseKinematics (const Eigen::VectorXd &initial_positions, Eigen::VectorXd &result, Args...args) const
	Solves for an inverse kinematics solution given a set of objectives. More...

	~RobotModel () noexcept
	Destructor cleans up robot model object, including all managed elements. More...

Private Member Functions
template<typename T >
HebiStatusCode	addObjectives (HebiIKPtr ik, const T &objective) const

template<typename T , typename... Args>
HebiStatusCode	addObjectives (HebiIKPtr ik, const T &objective, Args...args) const

bool	tryAdd (HebiRobotModelElementPtr element, bool combine)

Static Private Member Functions
static void	setRodXAxisInertia (Eigen::VectorXd &inertia, double mass, double length)

static void	setRotX (Eigen::Matrix4d &matrix, double radians)

static void	setSphereInertia (Eigen::VectorXd &inertia, double mass, double radius)

static void	setTranslate (Eigen::Matrix4d &matrix, double x, double y, double z)

Private Attributes
HebiRobotModelPtr const	internal_

friend	Objective

Static Private Attributes
static const std::map< ActuatorType, double >	actuator_masses_

Detailed Description

Represents a chain or tree of robot elements (rigid bodies and joints).

(Currently, only chains of elements are fully supported)

Definition at line 86 of file robot_model.hpp.

Member Enumeration Documentation

enum hebi::robot_model::RobotModel::ActuatorType

strong

Enumerator
X5_1
X5_4
X5_9
X8_3
X8_9
X8_16

Definition at line 148 of file robot_model.hpp.

enum hebi::robot_model::RobotModel::BracketType

strong

Enumerator
X5LightLeft
X5LightRight
X5HeavyLeftInside
X5HeavyLeftOutside
X5HeavyRightInside
X5HeavyRightOutside

Definition at line 163 of file robot_model.hpp.

enum hebi::robot_model::RobotModel::LinkType

strong

Enumerator
X5

Definition at line 158 of file robot_model.hpp.

Constructor & Destructor Documentation

hebi::robot_model::RobotModel::RobotModel ( )

Creates a robot model object with no bodies and an identity base frame.

Definition at line 143 of file robot_model.cpp.

hebi::robot_model::RobotModel::~RobotModel ( )

noexcept

Destructor cleans up robot model object, including all managed elements.

Definition at line 148 of file robot_model.cpp.

Member Function Documentation

bool hebi::robot_model::RobotModel::addActuator ( ActuatorType actuator_type )

Add an element to the robot model with the kinematics/dynamics of an X5 actuator.

Parameters

actuator_type The type of actuator to add.

Definition at line 229 of file robot_model.cpp.

bool hebi::robot_model::RobotModel::addBracket ( BracketType bracket_type )

Add an element to the robot model with the kinematics/dynamics of a bracket between two actuators.

Parameters

bracket_type The type of bracket to add.

Definition at line 315 of file robot_model.cpp.

bool hebi::robot_model::RobotModel::addJoint	(	HebiJointType	joint_type,
		bool	combine
	)

Adds a degree of freedom about the specified axis.

This does not represent an element with size or mass, but only a connection between two other elements about a particular axis.

Parameters

joint_type The axis of rotation or translation about which this joint allows motion.

Definition at line 222 of file robot_model.cpp.

bool hebi::robot_model::RobotModel::addLink	(	LinkType	link_type,
		double	extension,
		double	twist
	)

Add an element to the robot model with the kinematics/dynamics of a link between two actuators.

Parameters

link_type	The type of link between the actuators, e.g. a tube link between two X5 or X8 actuators.
extension	The center-to-center distance between the actuator rotational axes.
twist	The rotation (in radians) between the actuator axes of rotation. Note that a 0 radian rotation will result in a z-axis offset between the two actuators, and a pi radian rotation will result in the actuator interfaces to this tube being in the same plane, but the rotational axes being anti-parallel.

Definition at line 284 of file robot_model.cpp.

template<typename T >

HebiStatusCode hebi::robot_model::RobotModel::addObjectives	(	HebiIKPtr	ik,
		const T &	objective
	)		const

inlineprivate

Internal function for resolving variadic template (stops recursion and detects invalid arguments).

Definition at line 101 of file robot_model.hpp.

template<typename T , typename... Args>

HebiStatusCode hebi::robot_model::RobotModel::addObjectives	(	HebiIKPtr	ik,
		const T &	objective,
		Args...	args
	)		const

inlineprivate

Internal function for resolving variadic template.

Definition at line 112 of file robot_model.hpp.

bool hebi::robot_model::RobotModel::addRigidBody	(	const Eigen::Matrix4d &	com,
		const Eigen::VectorXd &	inertia,
		double	mass,
		const Eigen::Matrix4d &	output,
		bool	combine
	)

Adds a rigid body with the specified properties to the robot model.

This can be 'combined' with the parent element (the element this is attaching to), which means that the mass, inertia, and output frames of this element will be integrated with the parent. The mass will be combined, and the reported parent output frame that this element attached to will be replaced with the output from this element (so that the number of output frames and masses remains constant).

Parameters

com	4x4 matric of the homogeneous transform to the center of mass location, relative to the input frame of the element. Note that this frame is also the frame the inertia tensor is given in.
inertia	The 6 element representation (Ixx, Iyy, Izz, Ixy, Ixz, Iyz) of the inertia tensor, in the frame given by the COM.
output	4x4 matrix of the homogeneous transform to the output frame, relative to the input frame of the element.
mass	The mass of this element.
combine	'True' if the frames and masses of this body should be combined with the parent, 'false' otherwise.

Definition at line 186 of file robot_model.cpp.

Eigen::Matrix4d hebi::robot_model::RobotModel::getBaseFrame ( ) const

Returns the transform from the world coordinate system to the root kinematic body, as set by the setBaseFrame function.

Definition at line 162 of file robot_model.cpp.

size_t hebi::robot_model::RobotModel::getDoFCount ( ) const

Returns the number of settable degrees of freedom in the kinematic tree. (This is equal to the number of actuators added).

Definition at line 180 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getEndEffector	(	const Eigen::VectorXd &	positions,
		Eigen::Matrix4d &	transform
	)		const

Generates the forward kinematics to the end effector (leaf node) frame(s).

Note – for center of mass frames, this is one per leaf node; for output frames, this is one per output per leaf node, in depth first order.

This overload is for kinematic chains that only have a single leaf node frame.

(Currently, kinematic trees are not fully supported – only kinematic chains – and so there are not other overloads for this function).

Parameters

frame_type	Which type of frame to consider – see HebiFrameType enum.
positions	A vector of joint positions/angles (in SI units of meters or radians) equal in length to the number of DoFs of the kinematic tree.
transform	A 4x4 transform that is resized as necessary in the function and filled in with the homogeneous transform to the end effector frame.

Definition at line 400 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getFK	(	HebiFrameType	frame_type,
		const Eigen::VectorXd &	positions,
		Matrix4dVector &	frames
	)		const

Generates the forward kinematics for the given robot model.

The order of the returned frames is in a depth-first tree. As an example, assume a body A has one output, to which body B is connected to. Body B has two outputs; actuator C is attached to the first output and actuator E is attached to the second output. Body D is attached to the only output of actuator C:

(BASE) A - B(1) - C - D (2) | E

For center of mass frames, the returned frames would be A-B-C-D-E.

For output frames, the returned frames would be A-B(1)-C-D-B(2)-E.

Parameters

frame_type	Which type of frame to consider – see HebiFrameType enum.
positions	A vector of joint positions/angles (in SI units of meters or radians) equal in length to the number of DoFs of the kinematic tree.
frames	An array of 4x4 transforms; this is resized as necessary in the function and filled in with the 4x4 homogeneous transform of each frame. Note that the number of frames depends on the frame type.

Definition at line 377 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getForwardKinematics	(	HebiFrameType	frame_type,
		const Eigen::VectorXd &	positions,
		Matrix4dVector &	frames
	)		const

Generates the forward kinematics for the given robot model.

See getFK for details.

Definition at line 372 of file robot_model.cpp.

size_t hebi::robot_model::RobotModel::getFrameCount ( HebiFrameType frame_type ) const

Return the number of frames in the forward kinematics.

Note that this depends on the type of frame requested – for center of mass frames, there is one per added body; for output frames, there is one per output per body.

Parameters

frame_type Which type of frame to consider – see HebiFrameType enum.

Definition at line 175 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getJ	(	HebiFrameType	frame_type,
		const Eigen::VectorXd &	positions,
		MatrixXdVector &	jacobians
	)		const

Generates the Jacobian for each frame in the given kinematic tree.

Parameters

frame_type	Which type of frame to consider – see HebiFrameType enum.
positions	A vector of joint positions/angles (in SI units of meters or radians) equal in length to the number of DoFs of the kinematic tree.
jacobians	A vector (length equal to the number of frames) of matrices; each matrix is a (6 x number of dofs) jacobian matrix for the corresponding frame of reference on the robot. This vector is resized as necessary inside this function.

Definition at line 422 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getJacobianEndEffector	(	const Eigen::VectorXd &	positions,
		Eigen::MatrixXd &	jacobian
	)		const

Generates the Jacobian for the end effector (leaf node) frames(s).

See getJEndEffector for details.

Definition at line 446 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getJacobians	(	HebiFrameType	frame_type,
		const Eigen::VectorXd &	positions,
		MatrixXdVector &	jacobians
	)		const

Generates the Jacobian for each frame in the given kinematic tree.

See getJ for details.

Definition at line 418 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getJEndEffector	(	const Eigen::VectorXd &	positions,
		Eigen::MatrixXd &	jacobian
	)		const

Generates the Jacobian for the end effector (leaf node) frames(s).

Note – for center of mass frames, this is one per leaf node; for output frames, this is one per output per leaf node, in depth first order.

This overload is for kinematic chains that only have a single leaf node frame.

(Currently, kinematic trees are not fully supported – only kinematic chains – and so there are not other overloads for this function).

Parameters

positions	A vector of joint positions/angles (in SI units of meters or radians) equal in length to the number of DoFs of the kinematic tree.
jacobian	A (6 x number of dofs) jacobian matrix for the corresponding end effector frame of reference on the robot. This vector is resized as necessary inside this function.

Definition at line 450 of file robot_model.cpp.

void hebi::robot_model::RobotModel::getMasses ( Eigen::VectorXd & masses ) const

Returns the mass of each rigid body (or combination of rigid bodies) in the robot model.

Parameters

masses A vector which is filled with the masses in the robot model. This vector is resized as necessary inside this function (it is set to have length equal to the number of com frames).

Definition at line 463 of file robot_model.cpp.

void hebi::robot_model::RobotModel::setBaseFrame ( const Eigen::Matrix4d & base_frame )

Set the transform from a world coordinate system to the input of the root element in this robot model object. Defaults to an identity 4x4 matrix.

The world coordinate system is used for all position, vector, and transformation matrix parameters in the member functions.

Parameters

base_frame The 4x4 homogeneous transform from the world frame to the root kinematic body frame.

Definition at line 153 of file robot_model.cpp.

void hebi::robot_model::RobotModel::setRodXAxisInertia	(	Eigen::VectorXd &	inertia,
		double	mass,
		double	length
	)

staticprivate

Internal function for row-major double-array matrix manipulation

Definition at line 120 of file robot_model.cpp.

void hebi::robot_model::RobotModel::setRotX	(	Eigen::Matrix4d &	matrix,
		double	radians
	)

staticprivate

Internal function for row-major double-array matrix manipulation

Definition at line 97 of file robot_model.cpp.

void hebi::robot_model::RobotModel::setSphereInertia	(	Eigen::VectorXd &	inertia,
		double	mass,
		double	radius
	)

staticprivate

Internal function for row-major double-array matrix manipulation

Definition at line 109 of file robot_model.cpp.

void hebi::robot_model::RobotModel::setTranslate	(	Eigen::Matrix4d &	matrix,
		double	x,
		double	y,
		double	z
	)

staticprivate

Internal function for row-major double-array matrix manipulation

Definition at line 90 of file robot_model.cpp.

template<typename... Args>

IKResult hebi::robot_model::RobotModel::solveIK	(	const Eigen::VectorXd &	initial_positions,
		Eigen::VectorXd &	result,
		Args...	objectives
	)		const

inline

Solves for an inverse kinematics solution given a set of objectives.

Parameters

initial_positions	The seed positions/angles (in SI units of meters or radians) to start the IK search from; equal in length to the number of DoFs of the kinematic tree.
result	A vector equal in length to the number of DoFs of the kinematic tree; this will be filled in with the IK solution (in SI units of meters or radians), and resized as necessary.
objectives	A variable number of objectives used to define the IK search (e.g., target end effector positions, etc). Each argument must have a base class of Objective.

Definition at line 377 of file robot_model.hpp.

template<typename... Args>

IKResult hebi::robot_model::RobotModel::solveInverseKinematics	(	const Eigen::VectorXd &	initial_positions,
		Eigen::VectorXd &	result,
		Args...	args
	)		const

inline

Solves for an inverse kinematics solution given a set of objectives.

See solveIK for details.

Definition at line 357 of file robot_model.hpp.

bool hebi::robot_model::RobotModel::tryAdd	(	HebiRobotModelElementPtr	element,
		bool	combine
	)

private

Internal function for adding robot model elements

Definition at line 131 of file robot_model.cpp.

Member Data Documentation

const std::map< RobotModel::ActuatorType, double > hebi::robot_model::RobotModel::actuator_masses_

staticprivate

Initial value:

=  {
  std::make_pair(ActuatorType::X5_1, 0.315),
  std::make_pair(ActuatorType::X5_4, 0.335),
  std::make_pair(ActuatorType::X5_9, 0.360),
  std::make_pair(ActuatorType::X8_3, 0.460),
  std::make_pair(ActuatorType::X8_9, 0.480),
  std::make_pair(ActuatorType::X8_16, 0.500)
}

Helper data structure that contains masses for various actuators

Definition at line 479 of file robot_model.hpp.

HebiRobotModelPtr const hebi::robot_model::RobotModel::internal_

private

C-style robot model object

Definition at line 94 of file robot_model.hpp.

friend hebi::robot_model::RobotModel::Objective

private

Definition at line 88 of file robot_model.hpp.

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

Public Types

Public Member Functions

Private Member Functions

Static Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation