tutorials/tut03_gravity_compensation.cpp File Reference

Author:

Roland Philippsen

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#include "tutsim.hpp"
#include <opspace/Task.hpp>
#include <jspace/test/sai_util.hpp>
#include <boost/shared_ptr.hpp>
#include <err.h>

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Namespaces
namespace	tut03
Classes
class	tut03::JTask
Functions
static std::string	model_filename (TUTROB_XML_PATH_STR)
static size_t	mode (0)
static bool	servo_cb (size_t toggle_count, double wall_time_ms, double sim_time_ms, jspace::State &state, jspace::Vector &command)
static void	draw_cb (double x0, double y0, double scale)
int	main (int argc, char **argv)
Variables
static boost::shared_ptr < jspace::Model >	model
static boost::shared_ptr < tut03::JTask >	jtask

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Detailed Description

Author:

Roland Philippsen

This tutorial demonstrates the effect of gravity compensation. It is very similar to the tutorial number 2 in that it uses a custom opspace::Task subclass that is just a simple joint-position PD servo. However, the tut03::JTask class contains a flag to switch gravity compensation on or off.

When the tutorial starts, it is in a mode where the robot position and velocity gets constantly re-initialized to a swaying motion. When you press Toggle, it switches to joint-space position control with gravity compensation, using the current joint position as goal. The robot will thus overshoot due to its current velocity, and then converge back to the position it had when you clicked Toggle. Then, when you press Toggle again, it will keep servoing but switch off gravity compensation. This will make the robot "sag" with respect to its desired position, illustrating the effect of gravity. Clicking Toggle again goes back to the swaying motion and the cycle repeats.

Definition in file tut03_gravity_compensation.cpp.

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Function Documentation

static void draw_cb	(	double	x0,
		double	y0,
		double	scale
	)			[static]

Definition at line 210 of file tut03_gravity_compensation.cpp.

References tutsim::draw_delta_jpos(), tutsim::draw_robot(), jtask, and mode.

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int main	(	int	argc,
		char **	argv
	)

Definition at line 219 of file tut03_gravity_compensation.cpp.

References draw_cb, jtask, model, model_filename(), tutsim::run(), servo_cb, and tutsim::set_draw_cb().

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static size_t mode

(

0

)

[static]

static std::string model_filename

(

TUTROB_XML_PATH_STR

)

[static]

static bool servo_cb	(	size_t	toggle_count,
		double	wall_time_ms,
		double	sim_time_ms,
		jspace::State &	state,
		jspace::Vector &	command
	)			[static]

Definition at line 129 of file tut03_gravity_compensation.cpp.

References jtask, mode, model, jspace::State::position_, jspace::pretty_print(), and jspace::State::velocity_.

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Variable Documentation

boost::shared_ptr<tut03::JTask> jtask [static]

Definition at line 125 of file tut03_gravity_compensation.cpp.

boost::shared_ptr<jspace::Model> model [static]

Definition at line 124 of file tut03_gravity_compensation.cpp.

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