RecursiveNewtonEuler Class Reference

The recursive Newton-Euler method is used for calculating inverse dynamics of a kinematic tree. More...

#include <RecursiveNewtonEuler.hpp>

Classes
struct	Motion
	Motion of a body defined as velocity and acceleration. More...

Public Types
typedef rw::core::Ptr< RecursiveNewtonEuler >	Ptr
	smart pointer type to this class

Public Member Functions
	RecursiveNewtonEuler (rw::core::Ptr< rwsim::dynamics::RigidDevice > device)
	Constructor for inverse dynamics for a RigidDevice. More...
virtual	~RecursiveNewtonEuler ()
	Destructor.
rw::math::Vector3D	getGravity () const
	Get the used gravity in base coordinates. More...
void	setGravity (const rw::math::Vector3D<> &gravity)
	Set the gravity used. More...
rw::math::Vector3D	getPayloadCOM () const
	Get the center of mass of the payload in the tool frame. More...
double	getPayloadMass () const
	Get the mass of the payload. More...
rw::math::InertiaMatrix	getPayloadInertia () const
	Get the inertia of the payload. More...
void	setPayload (const rw::math::Vector3D<> &com, double payload, const rw::math::InertiaMatrix<> &inertia)
	Set the payload relative to the end frame of the device. More...
rw::math::Wrench6D	getEnvironment () const
	Get the force and torque that the robot exerts on the environment at the TCP frame in base coordinates. More...
void	setEnvironment (const rw::math::Wrench6D<> &wrench)
	Set the force and torque that the robot exerts on the environment at the TCP frame in base coordinates. More...
std::vector< Motion >	getBodyMotion (const rw::kinematics::State &state, const rw::math::Q &dq, const rw::math::Q &ddq) const
	Get the Motion of each link and the payload for a device that have accelerating joints. More...
std::vector< rw::math::Wrench6D<> >	getBodyNetForces (const std::vector< Motion > &motions, const rw::kinematics::State &state) const
	Determine the net force and torque acting on each link to achieve the given motion. More...
std::vector< rw::math::Wrench6D<> >	getJointForces (const std::vector< rw::math::Wrench6D<>> &bodyNetForces, const rw::kinematics::State &state) const
	Determine the forces and torques acting in each joint to achieve the given net forces and torques on the links and payload. More...
std::vector< rw::math::Wrench6D<> >	solve (const rw::kinematics::State &state, const rw::math::Q dq=rw::math::Q(), const rw::math::Q ddq=rw::math::Q()) const
	Do inverse dynamics for a robot in motion. More...
std::vector< double >	solveMotorTorques (const rw::kinematics::State &state, const rw::math::Q &dq, const rw::math::Q &ddq) const
	Get the torque provided by each motor. More...
bool	validate () const
	Check if solver will work for the given device - if not an exception will be thrown when trying to solve. More...

Detailed Description

The recursive Newton-Euler method is used for calculating inverse dynamics of a kinematic tree.

Constructor & Destructor Documentation

RecursiveNewtonEuler()

RecursiveNewtonEuler

(

rw::core::Ptr< rwsim::dynamics::RigidDevice >

device

)

Constructor for inverse dynamics for a RigidDevice.

Parameters

device

[in] a rigid device

Member Function Documentation

getBodyMotion()

std::vector<Motion> getBodyMotion	(	const rw::kinematics::State &	state,
		const rw::math::Q &	dq,
		const rw::math::Q &	ddq
	)		const

Get the Motion of each link and the payload for a device that have accelerating joints.

Parameters

state	[in] the state of the device
dq	[in] joint speeds
ddq	[in] joint accelerations

Returns

vector of velocities and accelerations of the center of mass of each body in base coordinates

getBodyNetForces()

std::vector<rw::math::Wrench6D<> > getBodyNetForces	(	const std::vector< Motion > &	motions,
		const rw::kinematics::State &	state
	)		const

Determine the net force and torque acting on each link to achieve the given motion.

Parameters

motions	[in] the motion of each link
state	[in] state (position) of the robot

Returns

the net forces and torques acting on each link as a vector

getEnvironment()

rw::math::Wrench6D getEnvironment

(

)

const

Get the force and torque that the robot exerts on the environment at the TCP frame in base coordinates.

Returns

a 6D wrench

getGravity()

rw::math::Vector3D getGravity

(

)

const

Get the used gravity in base coordinates.

Returns

gravity vector

getJointForces()

std::vector<rw::math::Wrench6D<> > getJointForces	(	const std::vector< rw::math::Wrench6D<>> &	bodyNetForces,
		const rw::kinematics::State &	state
	)		const

Determine the forces and torques acting in each joint to achieve the given net forces and torques on the links and payload.

Parameters

bodyNetForces	[in] the desired net forces and torques acting on each link in link local coordinate frames
state	[in] state (position) of the robot

Returns

the net forces and torques acting on each joint in base coordinates.

getPayloadCOM()

rw::math::Vector3D getPayloadCOM

(

)

const

Get the center of mass of the payload in the tool frame.

Returns

center of mass of the payload

getPayloadInertia()

rw::math::InertiaMatrix getPayloadInertia

(

)

const

Get the inertia of the payload.

Returns

inertia of payload in end frame of device.

getPayloadMass()

double getPayloadMass

(

)

const

Get the mass of the payload.

Returns

mass of payload in end frame of device.

setEnvironment()

void setEnvironment

(

const rw::math::Wrench6D<> &

wrench

)

Set the force and torque that the robot exerts on the environment at the TCP frame in base coordinates.

Parameters

wrench

[in] the wrench the robot exerts on the environment

setGravity()

void setGravity

(

const rw::math::Vector3D<> &

gravity

)

Set the gravity used.

Parameters

gravity

[in] vector giving the gravity in base coordinates.

setPayload()

void setPayload	(	const rw::math::Vector3D<> &	com,
		double	payload,
		const rw::math::InertiaMatrix<> &	inertia
	)

Set the payload relative to the end frame of the device.

Parameters

com	[in] the center of mass in the end frame.
payload	[in] the mass of the payload
inertia	[in] the inertia of the payload

solve()

std::vector<rw::math::Wrench6D<> > solve	(	const rw::kinematics::State &	state,
		const rw::math::Q	dq = rw::math::Q(),
		const rw::math::Q	ddq = rw::math::Q()
	)		const

Do inverse dynamics for a robot in motion.

Parameters

state	[in] state (position) of the robot
dq	[in] the joint velocities
ddq	[in] the joint accelerations

Returns

the wrenches working in each joint in base coordinates

solveMotorTorques()

std::vector<double> solveMotorTorques	(	const rw::kinematics::State &	state,
		const rw::math::Q &	dq,
		const rw::math::Q &	ddq
	)		const

Get the torque provided by each motor.

Parameters

state	[in] state (position) of the robot
dq	[in] the joint velocities
ddq	[in] the joint accelerations

Returns

the torques provided by each motor

validate()

bool validate

(

)

const

Check if solver will work for the given device - if not an exception will be thrown when trying to solve.

Returns

true if solver works for the given device, false otherwise.

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

• RecursiveNewtonEuler.hpp