opspace::TrajectoryTask Class Reference

Base class for acceleration-bounded trajectory tasks. More...

#include <task_library.hpp>

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List of all members.

Public Member Functions
virtual	~TrajectoryTask ()
virtual Status	check (double const *param, double value) const
	Checks that dt_seconds is positive and calls PDTask.
virtual Status	check (Vector const *param, Vector const &value) const
	If initialized, checks the validity of trjgoal and calls PDTask::check().
virtual void	dbg (std::ostream &os, std::string const &title, std::string const &prefix) const
Protected Types
typedef PDTask::saturation_policy_t	saturation_policy_t
	Velocity saturation policy.
Protected Member Functions
	TrajectoryTask (std::string const &name, saturation_policy_t saturation_policy)
Status	initTrajectoryTask (Vector const &initpos)
	Initializes the trajectory to be at the current position with zero velocity.
Status	computeTrajectoryCommand (Vector const &curpos, Vector const &curvel, Vector &command)
	Computes the command for following the trajectory.
Protected Attributes
TypeIOTGCursor *	cursor_
double	dt_seconds_
Vector	trjgoal_
Vector	maxacc_
Vector	qh_maxvel_

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Detailed Description

Base class for acceleration-bounded trajectory tasks.

Uses a PD control law to follow a trajectory generated using the reflexxes_otg library,

Parameters inherited from PDTask (this list may be outdated):

• goalpos (vector): desired position
• goalvel (vector): desired velocity
• kp (vector): proportional gain
• kd (vector): derivative gain
• maxvel (vector): velocity saturation limit

Parameters added by this base class:

• dt_seconds (real): iteration timestep, for trajectory generation
• trjgoal (vector): trajectory end point
• maxacc (vector): maximum acceleration of the trajectory

Subclasses should call initTrajectoryTask() from their init(), and computeTrajectoryCommand() from their computeCommand().

Definition at line 274 of file task_library.hpp.

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Member Typedef Documentation

typedef PDTask::saturation_policy_t opspace::TrajectoryTask::saturation_policy_t [protected]

Velocity saturation policy.

• SATURATION_OFF: do not saturate commands (use with caution)
• SATURATION_COMPONENT_WISE: each component of the position-error is scaled according to an individual saturation term
• SATURATION_MAX_COMPONENT: similar to SATURATION_COMPONENT_WISE, but the most saturated component determines the overall scaling.
• SATURATION_NORM: the vector norm of the position error is used to determine the saturation factor (this only makes sense if kp, kd, and maxvel are one-dimensional values, so this constraint is enforced in other parts of the PDTask implementation as well)

Reimplemented from opspace::PDTask.

Definition at line 296 of file task_library.hpp.

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Constructor & Destructor Documentation

opspace::TrajectoryTask::~TrajectoryTask

(

)

[virtual]

Definition at line 606 of file task_library.cpp.

References cursor_.

opspace::TrajectoryTask::TrajectoryTask	(	std::string const &	name,
		saturation_policy_t	saturation_policy
	)			[protected]

Definition at line 594 of file task_library.cpp.

References opspace::ParameterReflection::declareParameter(), dt_seconds_, maxacc_, opspace::PARAMETER_FLAG_NOLOG, and trjgoal_.

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Member Function Documentation

Status opspace::TrajectoryTask::check	(	double const *	param,
		double	value
	)			const [virtual]

Checks that dt_seconds is positive and calls PDTask.

Reimplemented from opspace::ParameterReflection.

Definition at line 686 of file task_library.cpp.

References dt_seconds_.

Status opspace::TrajectoryTask::check	(	Vector const *	param,
		Vector const &	value
	)			const [virtual]

If initialized, checks the validity of trjgoal and calls PDTask::check().

Reimplemented from opspace::PDTask.

Definition at line 696 of file task_library.cpp.

References opspace::PDTask::check(), cursor_, maxacc_, opspace::PDTask::maxvel_, opspace::TypeIOTGCursor::ndof_, qh_maxvel_, opspace::PDTask::SATURATION_NORM, opspace::PDTask::saturation_policy_, and trjgoal_.

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void opspace::TrajectoryTask::dbg	(	std::ostream &	os,
		std::string const &	title,
		std::string const &	prefix
	)			const [virtual]

Reimplemented from opspace::Task.

Definition at line 738 of file task_library.cpp.

References opspace::Task::actual_, cursor_, opspace::ParameterReflection::instance_name_, opspace::TypeIOTGCursor::position(), jspace::pretty_print(), and trjgoal_.

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Status opspace::TrajectoryTask::initTrajectoryTask

(

Vector const &

initpos

)

[protected]

Initializes the trajectory to be at the current position with zero velocity.

Also does some sanity checking and optional conversion of parameters. Similarly to PDTask::initPDTask(), single-dimensional parameters can get blown up to the right size, depending on the saturation policy.

Definition at line 613 of file task_library.cpp.

References cursor_, opspace::TypeIOTGCursor::dt_seconds_, dt_seconds_, jspace::Status::errstr, opspace::PDTask::initPDTask(), maxacc_, opspace::PDTask::maxvel_, jspace::Status::ok, opspace::TypeIOTGCursor::position(), qh_maxvel_, opspace::PDTask::SATURATION_NORM, opspace::PDTask::saturation_policy_, trjgoal_, and opspace::TypeIOTGCursor::velocity().

Referenced by opspace::JPosTrjTask::init(), and opspace::CartPosTrjTask::init().

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Status opspace::TrajectoryTask::computeTrajectoryCommand	(	Vector const &	curpos,
		Vector const &	curvel,
		Vector &	command
	)			[protected]

Computes the command for following the trajectory.

It advances the cursor by dt_seconds toward the trjgoal and servos to that position and velocity using PDTask::computePDCommand().

Definition at line 662 of file task_library.cpp.

References opspace::PDTask::computePDCommand(), cursor_, opspace::PDTask::goalpos_, opspace::PDTask::goalvel_, maxacc_, opspace::TypeIOTGCursor::next(), opspace::otg_errstr(), opspace::TypeIOTGCursor::position(), qh_maxvel_, trjgoal_, and opspace::TypeIOTGCursor::velocity().

Referenced by opspace::JPosTrjTask::update(), and opspace::CartPosTrjTask::update().

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Member Data Documentation

TypeIOTGCursor* opspace::TrajectoryTask::cursor_ [protected]

Definition at line 318 of file task_library.hpp.

Referenced by check(), computeTrajectoryCommand(), dbg(), initTrajectoryTask(), and ~TrajectoryTask().

double opspace::TrajectoryTask::dt_seconds_ [protected]

Definition at line 319 of file task_library.hpp.

Referenced by check(), initTrajectoryTask(), opspace::JPosTrjTask::quickSetup(), and TrajectoryTask().

Vector opspace::TrajectoryTask::trjgoal_ [protected]

Definition at line 320 of file task_library.hpp.

Referenced by check(), computeTrajectoryCommand(), dbg(), initTrajectoryTask(), and TrajectoryTask().

Vector opspace::TrajectoryTask::maxacc_ [protected]

Definition at line 321 of file task_library.hpp.

Referenced by check(), computeTrajectoryCommand(), initTrajectoryTask(), opspace::JPosTrjTask::quickSetup(), and TrajectoryTask().

Vector opspace::TrajectoryTask::qh_maxvel_ [mutable, protected]

Definition at line 322 of file task_library.hpp.

Referenced by check(), computeTrajectoryCommand(), and initTrajectoryTask().

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

• opspace/include/opspace/task_library.hpp
• opspace/src/task_library.cpp

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