humotion

/*

* This file is part of humotion

*

* Copyright(c) sschulz <AT> techfak.uni-bielefeld.de

* http://opensource.cit-ec.de/projects/humotion

*

* This file may be licensed under the terms of the

* GNU Lesser General Public License Version 3 (the ``LGPL''),

* or (at your option) any later version.

*

* Software distributed under the License is distributed

* on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either

* express or implied. See the LGPL for the specific language

* governing rights and limitations.

*

* You should have received a copy of the LGPL along with this

* program. If not, go to http://www.gnu.org/licenses/lgpl.html

* or write to the Free Software Foundation, Inc.,

* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

*

* The development of this software was supported by the

* Excellence Cluster EXC 277 Cognitive Interaction Technology.

* The Excellence Cluster EXC 277 is a grant of the Deutsche

* Forschungsgemeinschaft (DFG) in the context of the German

* Excellence Initiative.

*/

#include "humotion/server/gaze_motion_generator.h"

#include "humotion/server/server.h"

using humotion::server::GazeMotionGenerator;

// saccade detection threshold in deg/s

// const float GazeMotionGenerator::SACCADE_SPEED_THRESHOLD = 15.0;

// some constants to decide if the requested move will trigger a neck or eye saccade

const float GazeMotionGenerator::NECK_SACCADE_THRESHOLD      = 15.0;  // deg

const float GazeMotionGenerator::EYE_SACCADE_SPEED_THRESHOLD = 15.0;  // deg/s

// close to ocolumotor-range?

// 0.95 = reaching 95% of OMR will trigger a correction

const float GazeMotionGenerator::OMR_LIMIT_TRIGGERS_NECK_SACCADE = 0.95;

//! constructor

GazeMotionGenerator::GazeMotionGenerator(JointInterface *j, int dof, float t)

    : ReflexxesMotionGenerator(j, dof, t) {

}

//! destructor

GazeMotionGenerator::~GazeMotionGenerator() {

}

//! update gaze target:

//! \param GazeState with target values for the overall gaze

void GazeMotionGenerator::set_gaze_target(GazeState new_gaze_target) {

    if (requested_gaze_state.gaze_type == GazeState::GAZETYPE_RELATIVE) {

        printf("> ERROR: gaze targets should be converted to absolute before calling this\n");

        exit(EXIT_FAILURE);

    }

    // check magnitude of gaze change to detect eye-neck saccades

    float dist = fabs(requested_gaze_state.distance_pt_abs(new_gaze_target));

    // check requested speed

    float speed = fabs(requested_gaze_state.distance_pt_abs(new_gaze_target))

            / (new_gaze_target.timestamp.to_seconds()-requested_gaze_state.timestamp.to_seconds());

    // check magnitude and speed of gaze change to detect eye-neck saccades

    if (dist > NECK_SACCADE_THRESHOLD) {

        // the next saccade has to use neck motion as well

        if (speed > EYE_SACCADE_SPEED_THRESHOLD) {

            neck_saccade_requested = true;

        }

    } else {

        neck_saccade_requested = false;

    }

    // check for eye getting close to ocolomotor range

    // actually it makes more sense to trigger the neck saccade based on

    // the target getting out of the OMR

    float eye_target_l  = joint_interface->get_target_position(JointInterface::ID_EYES_LEFT_LR);

    float eye_target_r  = joint_interface->get_target_position(JointInterface::ID_EYES_RIGHT_LR);

    float eye_target_ud = joint_interface->get_target_position(JointInterface::ID_EYES_BOTH_UD);

    // min/max bounds

    float left_min  = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_min(JointInterface::ID_EYES_LEFT_LR);

    float left_max  = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_max(JointInterface::ID_EYES_LEFT_LR);

    float right_min = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_min(JointInterface::ID_EYES_RIGHT_LR);

    float right_max = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_max(JointInterface::ID_EYES_RIGHT_LR);

    float ud_min    = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_min(JointInterface::ID_EYES_BOTH_UD);

    float ud_max    = OMR_LIMIT_TRIGGERS_NECK_SACCADE *

            joint_interface->get_joint_max(JointInterface::ID_EYES_BOTH_UD);

    if (

            (eye_target_l < left_min) || (eye_target_l > left_max) ||

            (eye_target_r < right_min) || (eye_target_r > right_max) ||

            (eye_target_ud < ud_min) || (eye_target_ud > ud_max)) {

        // the eyeball gets close to OMR, activate a neck compensation motion

        neck_saccade_omr = true;

    } else {

        neck_saccade_omr = false;

    }

    // use base class set method

    MotionGenerator::set_gaze_target(new_gaze_target);

}

//! check if an eye saccade is active:

bool GazeMotionGenerator::get_eye_saccade_active() {

    bool saccade_active;

    float speed_left  = joint_interface->get_ts_speed(

                JointInterface::ID_EYES_LEFT_LR).get_newest_value();

    float speed_right = joint_interface->get_ts_speed(

                JointInterface::ID_EYES_RIGHT_LR).get_newest_value();

    float speed_tilt  = joint_interface->get_ts_speed(

                JointInterface::ID_EYES_BOTH_UD).get_newest_value();

    float speed_total_l = sqrt(speed_left*speed_left + speed_tilt*speed_tilt);

    float speed_total_r = sqrt(speed_right*speed_right + speed_tilt*speed_tilt);

    // thresholding

    if ((speed_total_l > EYE_SACCADE_SPEED_THRESHOLD) ||

            (speed_total_r > EYE_SACCADE_SPEED_THRESHOLD)) {

        // this is a saccade

        saccade_active = true;

    } else {

        saccade_active = false;

    }

    return saccade_active;

}

//! get overall gaze

humotion::GazeState GazeMotionGenerator::get_current_gaze() {

    // shortcut, makes the following easier to read

    JointInterface *j = joint_interface;

    GazeState gaze = requested_gaze_state;

    gaze.pan = j->get_ts_position(JointInterface::ID_NECK_PAN).get_newest_value() +

            (j->get_ts_position(JointInterface::ID_EYES_LEFT_LR).get_newest_value()

             + j->get_ts_position(JointInterface::ID_EYES_RIGHT_LR).get_newest_value())/2.0;

    gaze.tilt = j->get_ts_position(JointInterface::ID_NECK_TILT).get_newest_value()

            + j->get_ts_position(JointInterface::ID_EYES_BOTH_UD).get_newest_value();

    gaze.roll = j->get_ts_position(JointInterface::ID_NECK_ROLL).get_newest_value();

    gaze.vergence = j->get_ts_position(JointInterface::ID_EYES_LEFT_LR).get_newest_value()

            - j->get_ts_position(JointInterface::ID_EYES_RIGHT_LR).get_newest_value();

    return gaze;

}