def test_correct_xy_orientation(self):
     stationary_times = get_stationary_times(self.gps_speed)
     # reduce disturbance
     _, self.accelerations = reduce_disturbance(
         self.times, self.accelerations, reduce_disturbance_window_size)
     _, self.angular_velocities = reduce_disturbance(
         self.times, self.angular_velocities,
         reduce_disturbance_window_size)
     # convert measurement units
     converts_measurement_units(
         self.accelerations,
         self.angular_velocities,
         self.gps_speed,
     )
     # align on z-axis
     self.accelerations, self.angular_velocities = correct_z_orientation(
         self.accelerations, self.angular_velocities, stationary_times)
     # clear gyroscope drift
     self.angular_velocities = clear_gyro_drift(self.angular_velocities,
                                                stationary_times)
     # get number of records that means that there is is a bad xy alignment
     bad_align_count_len_before = get_xy_bad_align_count(
         self.accelerations, self.angular_velocities)
     # check that there is a bad alignment
     assert bad_align_count_len_before > 0
     # align on xy plane
     self.accelerations = correct_xy_orientation(self.accelerations,
                                                 self.angular_velocities)
     # re-get number of records that means that there is is a bad xy alignment
     bad_align_count_len_after = get_xy_bad_align_count(
         self.accelerations, self.angular_velocities)
     # these records should be now less than before
     assert bad_align_count_len_after <= bad_align_count_len_before
 def test_clearGyroDrift(self):
     drift_tolerance = 0.0002
     stationary_times = get_stationary_times(self.gps_speed,self.period)
     _, self.angular_velocities = reduce_disturbance(self.times, self.angular_velocities,reduce_disturbance_window_size)
     # get initial stationary time angular speed around x-axis
     initial_stationary_time_gx_value = self.angular_velocities[0, stationary_times[0][0]:stationary_times[0][1]].mean()
     # check there is a gyroscope drift
     assert abs(initial_stationary_time_gx_value) > drift_tolerance
     # call util to remove drift
     self.angular_velocities = clear_gyro_drift(self.angular_velocities,stationary_times)
     # re-calculate initial angular speed around x-axis
     initial_stationary_time_gx_value = self.angular_velocities[0, stationary_times[0][0]:stationary_times[0][1]].mean()
     # check that the drift is lower than a tolerance
     assert abs(initial_stationary_time_gx_value) < drift_tolerance
    # currently default format is unmodified fullinertial but other formats are / will be supported
    times, coordinates, altitudes, gps_speed, heading, accelerations, angular_velocities = parse_input(
        sys.argv[1], [InputType.UNMOD_FULLINERTIAL])

    converts_measurement_units(accelerations, np.array([0.1]), gps_speed,
                               coordinates, heading)

    normalize_timestamp(times)

    data_preprocessing_plot("Before")

    # reduce accelerations disturbance
    times, accelerations = reduce_disturbance(times, accelerations,
                                              window_size)
    # reduce angular velocities disturbance
    _, angular_velocities = reduce_disturbance(times, angular_velocities,
                                               window_size)
    # slice gps_speed to remove null values
    gps_speed = gps_speed[round(window_size / 2):-round(window_size / 2)]

    # get time windows where vehicle is stationary
    stationary_times = get_stationary_times(gps_speed)

    # clear gyroscope drift
    angular_velocities = clear_gyro_drift(angular_velocities, stationary_times)

    # 'after' data preprocessing plot
    data_preprocessing_plot("After")

    plt.show()
Example #4
0
def get_trajectory_from_path(path):
    """
    parse input file from path, clean data and integrate positions

    :param path: string input file
    :return: 3 numpy array: 3xn position, 1xn times, 4xn angular position as quaternions
    """

    window_size = 20

    # currently default format is unmodified fullinertial but other formats are / will be supported
    times, coordinates, altitudes, gps_speed, heading, accelerations, angular_velocities = parse_input(
        path, [InputType.UNMOD_FULLINERTIAL])

    converts_measurement_units(accelerations, angular_velocities, gps_speed,
                               coordinates, heading)

    # get positions from GNSS data
    gnss_positions, headings_2 = get_positions(coordinates, altitudes)

    # reduce accelerations disturbance
    times, accelerations = reduce_disturbance(times, accelerations,
                                              window_size)
    # reduce angular velocities disturbance
    _, angular_velocities = reduce_disturbance(times, angular_velocities,
                                               window_size)
    # truncate other array to match length of acc, thetas, times array
    gnss_positions = gnss_positions[:,
                                    round(window_size /
                                          2):-round(window_size / 2)]

    # with "final" times now get velocities and
    real_velocities = get_velocities(times, gnss_positions)
    # scalar speed from GNSS position (better than from dataset because avoids Kalmar filter)
    real_speeds = np.linalg.norm(real_velocities, axis=0)

    # get time windows where vehicle is stationary
    stationary_times = get_stationary_times(gps_speed)

    # clear gyroscope drift
    angular_velocities = clear_gyro_drift(angular_velocities, stationary_times)
    # set times start to 0
    normalize_timestamp(times)

    # correct z-axis alignment
    accelerations, angular_velocities = correct_z_orientation(
        accelerations, angular_velocities, stationary_times)

    # remove g
    accelerations[2] -= accelerations[
        2, stationary_times[0][0]:stationary_times[0][-1]].mean()

    # correct alignment in xy plane
    #accelerations = correct_xy_orientation(accelerations, angular_velocities)

    motion_time = get_first_motion_time(stationary_times, gnss_positions)
    initial_angular_position = get_initial_angular_position(
        gnss_positions, motion_time)

    # convert to laboratory frame of reference
    accelerations, angular_positions = rotate_accelerations(
        times, accelerations, angular_velocities, heading,
        initial_angular_position)

    # rotate to align y to north, x to east
    accelerations = align_to_world(gnss_positions, accelerations, motion_time)
    # angular position doesn't need to be aligned to world if starting angular position is already aligned and following
    # angular positions are calculated from that

    initial_speed = np.array([[gps_speed[0]], [0], [0]])
    # integrate acceleration with gss velocities correction
    correct_velocities = cumulative_integrate(times,
                                              accelerations,
                                              initial_speed,
                                              adjust_data=real_velocities,
                                              adjust_frequency=1)

    if sign_inversion_is_necessary(correct_velocities):
        accelerations *= -1
        correct_velocities *= -1

    correct_position = cumulative_integrate(times,
                                            correct_velocities,
                                            adjust_data=gnss_positions,
                                            adjust_frequency=1)

    return correct_position, times, angular_positions