def generate_residual(K):
    x_sym = sp.MatrixSymbol('abr', 3, 1)
    poses_sym = sp.MatrixSymbol('poses', 7 * K, 1)
    img_pos_sym = sp.MatrixSymbol('img_positions', 2 * K, 1)
    alpha, beta, rho = x_sym
    to_c = sp.Matrix(orient.rot_matrix(-np.pi / 2, -np.pi / 2, 0))
    pos_0 = sp.Matrix(np.array(poses_sym[K * 7 - 7:K * 7 - 4])[:, 0])
    q = poses_sym[K * 7 - 4:K * 7]
    quat_rot = quat_rotate(*q)
    rot_g_to_0 = to_c * quat_rot.T
    rows = []

    for i in range(K):
        pos_i = sp.Matrix(np.array(poses_sym[i * 7:i * 7 + 3])[:, 0])
        q = poses_sym[7 * i + 3:7 * i + 7]
        quat_rot = quat_rotate(*q)
        rot_g_to_i = to_c * quat_rot.T
        rot_0_to_i = rot_g_to_i * rot_g_to_0.T
        trans_0_to_i = rot_g_to_i * (pos_0 - pos_i)
        funct_vec = rot_0_to_i * sp.Matrix([alpha, beta, 1
                                            ]) + rho * trans_0_to_i
        h1, h2, h3 = funct_vec
        rows.append(h1 / h3 - img_pos_sym[i * 2 + 0])
        rows.append(h2 / h3 - img_pos_sym[i * 2 + 1])
    img_pos_residual_sym = sp.Matrix(rows)

    # sympy into c
    sympy_functions = []
    sympy_functions.append(
        ('res_fun', img_pos_residual_sym, [x_sym, poses_sym, img_pos_sym]))
    sympy_functions.append(('jac_fun', img_pos_residual_sym.jacobian(x_sym),
                            [x_sym, poses_sym, img_pos_sym]))

    return sympy_functions
Exemple #2
0
def generate_orient_error_jac(K):
    import sympy as sp
    from selfdrive.locationd.kalman.helpers.sympy_helpers import quat_rotate

    x_sym = sp.MatrixSymbol('abr', 3, 1)
    dtheta = sp.MatrixSymbol('dtheta', 3, 1)
    delta_quat = sp.Matrix(np.ones(4))
    delta_quat[1:, :] = sp.Matrix(0.5 * dtheta[0:3, :])
    poses_sym = sp.MatrixSymbol('poses', 7 * K, 1)
    img_pos_sym = sp.MatrixSymbol('img_positions', 2 * K, 1)
    alpha, beta, rho = x_sym
    to_c = sp.Matrix(orient.rot_matrix(-np.pi / 2, -np.pi / 2, 0))
    pos_0 = sp.Matrix(np.array(poses_sym[K * 7 - 7:K * 7 - 4])[:, 0])
    q = quat_matrix_l(poses_sym[K * 7 - 4:K * 7]) * delta_quat
    quat_rot = quat_rotate(*q)
    rot_g_to_0 = to_c * quat_rot.T
    rows = []
    for i in range(K):
        pos_i = sp.Matrix(np.array(poses_sym[i * 7:i * 7 + 3])[:, 0])
        q = quat_matrix_l(poses_sym[7 * i + 3:7 * i + 7]) * delta_quat
        quat_rot = quat_rotate(*q)
        rot_g_to_i = to_c * quat_rot.T
        rot_0_to_i = rot_g_to_i * (rot_g_to_0.T)
        trans_0_to_i = rot_g_to_i * (pos_0 - pos_i)
        funct_vec = rot_0_to_i * sp.Matrix([alpha, beta, 1
                                            ]) + rho * trans_0_to_i
        h1, h2, h3 = funct_vec
        rows.append(h1 / h3 - img_pos_sym[i * 2 + 0])
        rows.append(h2 / h3 - img_pos_sym[i * 2 + 1])
    img_pos_residual_sym = sp.Matrix(rows)

    # sympy into c
    sympy_functions = []
    sympy_functions.append(
        ('orient_error_jac', img_pos_residual_sym.jacobian(dtheta),
         [x_sym, poses_sym, img_pos_sym, dtheta]))

    return sympy_functions
Exemple #3
0
    def generate_code(N=4):
        dim_augment = LocKalman.dim_augment
        dim_augment_err = LocKalman.dim_augment_err

        dim_main = LocKalman.x_initial.shape[0]
        dim_main_err = LocKalman.P_initial.shape[0]
        dim_state = dim_main + dim_augment * N
        dim_state_err = dim_main_err + dim_augment_err * N
        maha_test_kinds = LocKalman.maha_test_kinds

        name = f"{LocKalman.name}_{N}"

        # make functions and jacobians with sympy
        # state variables
        state_sym = sp.MatrixSymbol('state', dim_state, 1)
        state = sp.Matrix(state_sym)
        x, y, z = state[States.ECEF_POS, :]
        q = state[States.ECEF_ORIENTATION, :]
        v = state[States.ECEF_VELOCITY, :]
        vx, vy, vz = v
        omega = state[States.ANGULAR_VELOCITY, :]
        vroll, vpitch, vyaw = omega
        #cb = state[States.CLOCK_BIAS, :][0, 0]
        #cd = state[States.CLOCK_DRIFT, :][0, 0]
        cb, cd = state[13:15, :]
        roll_bias, pitch_bias, yaw_bias = state[States.GYRO_BIAS, :]
        #odo_scale = state[States.ODO_SCALE, :][0,0]
        odo_scale = state[18, :]
        acceleration = state[States.ACCELERATION, :]
        #focal_scale = state[States.FOCAL_SCALE, :][0,0]
        focal_scale = state[22, :]
        imu_angles = state[States.IMU_OFFSET, :]
        glonass_bias, glonass_freq_slope = state[26:28, :]
        ca = state[28, 0]
        #glonass_bias = state[States.GLONASS_BIAS, :][0,0]
        #glonass_freq_slope = state[States.GLONASS_FREQ_SLOPE, :][0,0]
        #ca = state[States.CLOCK_ACCELERATION, :][0,0]

        dt = sp.Symbol('dt')

        # calibration and attitude rotation matrices
        quat_rot = quat_rotate(*q)

        # Got the quat predict equations from here
        # A New Quaternion-Based Kalman Filter for
        # Real-Time Attitude Estimation Using the Two-Step
        # Geometrically-Intuitive Correction Algorithm
        A = 0.5 * sp.Matrix(
            [[0, -vroll, -vpitch, -vyaw], [vroll, 0, vyaw, -vpitch],
             [vpitch, -vyaw, 0, vroll], [vyaw, vpitch, -vroll, 0]])
        q_dot = A * q

        # Time derivative of the state as a function of state
        state_dot = sp.Matrix(np.zeros((dim_state, 1)))
        state_dot[States.ECEF_POS, :] = v
        state_dot[States.ECEF_ORIENTATION, :] = q_dot
        state_dot[States.ECEF_VELOCITY, 0] = quat_rot * acceleration
        state_dot[13, 0] = cd
        state_dot[14, 0] = ca
        #state_dot[States.CLOCK_BIAS, 0][0,0] = cd
        state_dot[States.CLOCK_DRIFT, 0][0, 0] = ca

        # Basic descretization, 1st order intergrator
        # Can be pretty bad if dt is big
        f_sym = state + dt * state_dot

        state_err_sym = sp.MatrixSymbol('state_err', dim_state_err, 1)
        state_err = sp.Matrix(state_err_sym)
        quat_err = state_err[States.ECEF_ORIENTATION_ERR, :]
        v_err = state_err[States.ECEF_VELOCITY_ERR, :]
        omega_err = state_err[States.ANGULAR_VELOCITY_ERR, :]
        #cd_err = state_err[States.CLOCK_DRIFT_ERR, :][0,:]
        cd_err = state_err[13, :]
        acceleration_err = state_err[States.ACCELERATION_ERR, :]
        ca_err = state_err[27, :]

        # Time derivative of the state error as a function of state error and state
        quat_err_matrix = euler_rotate(quat_err[0], quat_err[1], quat_err[2])
        q_err_dot = quat_err_matrix * quat_rot * (omega + omega_err)
        state_err_dot = sp.Matrix(np.zeros((dim_state_err, 1)))
        state_err_dot[States.ECEF_POS_ERR, :] = v_err
        state_err_dot[States.ECEF_ORIENTATION_ERR, :] = q_err_dot
        state_err_dot[
            States.ECEF_VELOCITY_ERR, :] = quat_err_matrix * quat_rot * (
                acceleration + acceleration_err)
        #state_err_dot[States.CLOCK_BIAS_ERR, :][0,:] = cd_err
        #state_err_dot[States.CLOCK_DRIFT_ERR, :][0,:] = ca_err
        state_err_dot[12, :][0, :] = cd_err
        state_err_dot[13, :][0, :] = ca_err
        f_err_sym = state_err + dt * state_err_dot

        # convenient indexing
        # q idxs are for quats and p idxs are for other
        q_idxs = [[3, dim_augment]] + [[
            dim_main + n * dim_augment + 3, dim_main + (n + 1) * dim_augment
        ] for n in range(N)]
        q_err_idxs = [[3, dim_augment_err]] + [[
            dim_main_err + n * dim_augment_err + 3, dim_main_err +
            (n + 1) * dim_augment_err
        ] for n in range(N)]
        p_idxs = [[0, 3]] + [[dim_augment, dim_main]] + [[
            dim_main + n * dim_augment, dim_main + n * dim_augment + 3
        ] for n in range(N)]
        p_err_idxs = [[0, 3]] + [[dim_augment_err, dim_main_err]] + [[
            dim_main_err + n * dim_augment_err,
            dim_main_err + n * dim_augment_err + 3
        ] for n in range(N)]

        # Observation matrix modifier
        H_mod_sym = sp.Matrix(np.zeros((dim_state, dim_state_err)))
        for p_idx, p_err_idx in zip(p_idxs, p_err_idxs):
            H_mod_sym[p_idx[0]:p_idx[1],
                      p_err_idx[0]:p_err_idx[1]] = np.eye(p_idx[1] - p_idx[0])
        for q_idx, q_err_idx in zip(q_idxs, q_err_idxs):
            H_mod_sym[q_idx[0]:q_idx[1],
                      q_err_idx[0]:q_err_idx[1]] = 0.5 * quat_matrix_r(
                          state[q_idx[0]:q_idx[1]])[:, 1:]

        # these error functions are defined so that say there
        # is a nominal x and true x:
        # true x = err_function(nominal x, delta x)
        # delta x = inv_err_function(nominal x, true x)
        nom_x = sp.MatrixSymbol('nom_x', dim_state, 1)
        true_x = sp.MatrixSymbol('true_x', dim_state, 1)
        delta_x = sp.MatrixSymbol('delta_x', dim_state_err, 1)

        err_function_sym = sp.Matrix(np.zeros((dim_state, 1)))
        for q_idx, q_err_idx in zip(q_idxs, q_err_idxs):
            delta_quat = sp.Matrix(np.ones((4)))
            delta_quat[1:, :] = sp.Matrix(
                0.5 * delta_x[q_err_idx[0]:q_err_idx[1], :])
            err_function_sym[q_idx[0]:q_idx[1], 0] = quat_matrix_r(
                nom_x[q_idx[0]:q_idx[1], 0]) * delta_quat
        for p_idx, p_err_idx in zip(p_idxs, p_err_idxs):
            err_function_sym[p_idx[0]:p_idx[1], :] = sp.Matrix(
                nom_x[p_idx[0]:p_idx[1], :] +
                delta_x[p_err_idx[0]:p_err_idx[1], :])

        inv_err_function_sym = sp.Matrix(np.zeros((dim_state_err, 1)))
        for p_idx, p_err_idx in zip(p_idxs, p_err_idxs):
            inv_err_function_sym[p_err_idx[0]:p_err_idx[1],
                                 0] = sp.Matrix(-nom_x[p_idx[0]:p_idx[1], 0] +
                                                true_x[p_idx[0]:p_idx[1], 0])
        for q_idx, q_err_idx in zip(q_idxs, q_err_idxs):
            delta_quat = quat_matrix_r(
                nom_x[q_idx[0]:q_idx[1], 0]).T * true_x[q_idx[0]:q_idx[1], 0]
            inv_err_function_sym[q_err_idx[0]:q_err_idx[1],
                                 0] = sp.Matrix(2 * delta_quat[1:])

        eskf_params = [[err_function_sym, nom_x, delta_x],
                       [inv_err_function_sym, nom_x, true_x], H_mod_sym,
                       f_err_sym, state_err_sym]
        #
        # Observation functions
        #

        # extra args
        sat_pos_freq_sym = sp.MatrixSymbol('sat_pos', 4, 1)
        sat_pos_vel_sym = sp.MatrixSymbol('sat_pos_vel', 6, 1)
        sat_los_sym = sp.MatrixSymbol('sat_los', 3, 1)
        orb_epos_sym = sp.MatrixSymbol('orb_epos_sym', 3, 1)

        # expand extra args
        sat_x, sat_y, sat_z, glonass_freq = sat_pos_freq_sym
        sat_vx, sat_vy, sat_vz = sat_pos_vel_sym[3:]
        los_x, los_y, los_z = sat_los_sym
        orb_x, orb_y, orb_z = orb_epos_sym

        h_pseudorange_sym = sp.Matrix(
            [sp.sqrt((x - sat_x)**2 + (y - sat_y)**2 + (z - sat_z)**2) + cb])

        h_pseudorange_glonass_sym = sp.Matrix([
            sp.sqrt((x - sat_x)**2 + (y - sat_y)**2 + (z - sat_z)**2) + cb +
            glonass_bias + glonass_freq_slope * glonass_freq
        ])

        los_vector = (sp.Matrix(sat_pos_vel_sym[0:3]) - sp.Matrix([x, y, z]))
        los_vector = los_vector / sp.sqrt(los_vector[0]**2 + los_vector[1]**2 +
                                          los_vector[2]**2)
        h_pseudorange_rate_sym = sp.Matrix([
            los_vector[0] * (sat_vx - vx) + los_vector[1] * (sat_vy - vy) +
            los_vector[2] * (sat_vz - vz) + cd
        ])

        imu_rot = euler_rotate(*imu_angles)
        h_gyro_sym = imu_rot * sp.Matrix(
            [vroll + roll_bias, vpitch + pitch_bias, vyaw + yaw_bias])

        pos = sp.Matrix([x, y, z])
        gravity = quat_rot.T * ((EARTH_GM /
                                 ((x**2 + y**2 + z**2)**(3.0 / 2.0))) * pos)
        h_acc_sym = imu_rot * (gravity + acceleration)
        h_phone_rot_sym = sp.Matrix([vroll, vpitch, vyaw])

        speed = sp.sqrt(vx**2 + vy**2 + vz**2)
        h_speed_sym = sp.Matrix([speed * odo_scale])

        # orb stuff
        orb_pos_sym = sp.Matrix([orb_x - x, orb_y - y, orb_z - z])
        orb_pos_rot_sym = quat_rot.T * orb_pos_sym
        s = orb_pos_rot_sym[0]
        h_orb_point_sym = sp.Matrix([(1 / s) * (orb_pos_rot_sym[1]),
                                     (1 / s) * (orb_pos_rot_sym[2])])

        h_pos_sym = sp.Matrix([x, y, z])
        h_imu_frame_sym = sp.Matrix(imu_angles)

        h_relative_motion = sp.Matrix(quat_rot.T * v)

        obs_eqs = [
            [h_speed_sym, ObservationKind.ODOMETRIC_SPEED, None],
            [h_gyro_sym, ObservationKind.PHONE_GYRO, None],
            [h_phone_rot_sym, ObservationKind.NO_ROT, None],
            [h_acc_sym, ObservationKind.PHONE_ACCEL, None],
            [
                h_pseudorange_sym, ObservationKind.PSEUDORANGE_GPS,
                sat_pos_freq_sym
            ],
            [
                h_pseudorange_glonass_sym, ObservationKind.PSEUDORANGE_GLONASS,
                sat_pos_freq_sym
            ],
            [
                h_pseudorange_rate_sym, ObservationKind.PSEUDORANGE_RATE_GPS,
                sat_pos_vel_sym
            ],
            [
                h_pseudorange_rate_sym,
                ObservationKind.PSEUDORANGE_RATE_GLONASS, sat_pos_vel_sym
            ], [h_pos_sym, ObservationKind.ECEF_POS, None],
            [h_relative_motion, ObservationKind.CAMERA_ODO_TRANSLATION, None],
            [h_phone_rot_sym, ObservationKind.CAMERA_ODO_ROTATION, None],
            [h_imu_frame_sym, ObservationKind.IMU_FRAME, None],
            [h_orb_point_sym, ObservationKind.ORB_POINT, orb_epos_sym]
        ]

        # MSCKF configuration
        if N > 0:
            focal_scale = 1
            # Add observation functions for orb feature tracks
            track_epos_sym = sp.MatrixSymbol('track_epos_sym', 3, 1)
            track_x, track_y, track_z = track_epos_sym
            h_track_sym = sp.Matrix(np.zeros(((1 + N) * 2, 1)))
            track_pos_sym = sp.Matrix([track_x - x, track_y - y, track_z - z])
            track_pos_rot_sym = quat_rot.T * track_pos_sym
            h_track_sym[-2:, :] = sp.Matrix([
                focal_scale * (track_pos_rot_sym[1] / track_pos_rot_sym[0]),
                focal_scale * (track_pos_rot_sym[2] / track_pos_rot_sym[0])
            ])

            h_msckf_test_sym = sp.Matrix(np.zeros(((1 + N) * 3, 1)))
            h_msckf_test_sym[-3:, :] = sp.Matrix(
                [track_x - x, track_y - y, track_z - z])

            for n in range(N):
                idx = dim_main + n * dim_augment
                err_idx = dim_main_err + n * dim_augment_err  # FIXME: Why is this not used?
                x, y, z = state[idx:idx + 3]
                q = state[idx + 3:idx + 7]
                quat_rot = quat_rotate(*q)
                track_pos_sym = sp.Matrix(
                    [track_x - x, track_y - y, track_z - z])
                track_pos_rot_sym = quat_rot.T * track_pos_sym
                h_track_sym[n * 2:n * 2 + 2, :] = sp.Matrix([
                    focal_scale *
                    (track_pos_rot_sym[1] / track_pos_rot_sym[0]),
                    focal_scale * (track_pos_rot_sym[2] / track_pos_rot_sym[0])
                ])
                h_msckf_test_sym[n * 3:n * 3 + 3, :] = sp.Matrix(
                    [track_x - x, track_y - y, track_z - z])

            obs_eqs.append(
                [h_msckf_test_sym, ObservationKind.MSCKF_TEST, track_epos_sym])
            obs_eqs.append(
                [h_track_sym, ObservationKind.ORB_FEATURES, track_epos_sym])
            obs_eqs.append([
                h_track_sym, ObservationKind.FEATURE_TRACK_TEST, track_epos_sym
            ])
            msckf_params = [
                dim_main, dim_augment, dim_main_err, dim_augment_err, N,
                [ObservationKind.MSCKF_TEST, ObservationKind.ORB_FEATURES]
            ]
        else:
            msckf_params = None
        gen_code(name, f_sym, dt, state_sym, obs_eqs, dim_state, dim_state_err,
                 eskf_params, msckf_params, maha_test_kinds)
Exemple #4
0
  def generate_code():
    name = LiveKalman.name
    dim_state = LiveKalman.initial_x.shape[0]
    dim_state_err = LiveKalman.initial_P_diag.shape[0]

    state_sym = sp.MatrixSymbol('state', dim_state, 1)
    state = sp.Matrix(state_sym)
    x, y, z = state[States.ECEF_POS, :]
    q = state[States.ECEF_ORIENTATION, :]
    v = state[States.ECEF_VELOCITY, :]
    vx, vy, vz = v
    omega = state[States.ANGULAR_VELOCITY, :]
    vroll, vpitch, vyaw = omega
    roll_bias, pitch_bias, yaw_bias = state[States.GYRO_BIAS, :]
    odo_scale = state[States.ODO_SCALE, :][0,:]
    acceleration = state[States.ACCELERATION, :]
    imu_angles = state[States.IMU_OFFSET, :]

    dt = sp.Symbol('dt')

    # calibration and attitude rotation matrices
    quat_rot = quat_rotate(*q)

    # Got the quat predict equations from here
    # A New Quaternion-Based Kalman Filter for
    # Real-Time Attitude Estimation Using the Two-Step
    # Geometrically-Intuitive Correction Algorithm
    A = 0.5 * sp.Matrix([[0, -vroll, -vpitch, -vyaw],
                         [vroll, 0, vyaw, -vpitch],
                         [vpitch, -vyaw, 0, vroll],
                         [vyaw, vpitch, -vroll, 0]])
    q_dot = A * q

    # Time derivative of the state as a function of state
    state_dot = sp.Matrix(np.zeros((dim_state, 1)))
    state_dot[States.ECEF_POS, :] = v
    state_dot[States.ECEF_ORIENTATION, :] = q_dot
    state_dot[States.ECEF_VELOCITY, 0] = quat_rot * acceleration

    # Basic descretization, 1st order intergrator
    # Can be pretty bad if dt is big
    f_sym = state + dt * state_dot

    state_err_sym = sp.MatrixSymbol('state_err', dim_state_err, 1)
    state_err = sp.Matrix(state_err_sym)
    quat_err = state_err[States.ECEF_ORIENTATION_ERR, :]
    v_err = state_err[States.ECEF_VELOCITY_ERR, :]
    omega_err = state_err[States.ANGULAR_VELOCITY_ERR, :]
    acceleration_err = state_err[States.ACCELERATION_ERR, :]

    # Time derivative of the state error as a function of state error and state
    quat_err_matrix = euler_rotate(quat_err[0], quat_err[1], quat_err[2])
    q_err_dot = quat_err_matrix * quat_rot * (omega + omega_err)
    state_err_dot = sp.Matrix(np.zeros((dim_state_err, 1)))
    state_err_dot[States.ECEF_POS_ERR, :] = v_err
    state_err_dot[States.ECEF_ORIENTATION_ERR, :] = q_err_dot
    state_err_dot[States.ECEF_VELOCITY_ERR, :] = quat_err_matrix * quat_rot * (acceleration + acceleration_err)
    f_err_sym = state_err + dt * state_err_dot

    # Observation matrix modifier
    H_mod_sym = sp.Matrix(np.zeros((dim_state, dim_state_err)))
    H_mod_sym[States.ECEF_POS, States.ECEF_POS_ERR] = np.eye(States.ECEF_POS.stop - States.ECEF_POS.start)
    H_mod_sym[States.ECEF_ORIENTATION, States.ECEF_ORIENTATION_ERR] = 0.5 * quat_matrix_r(state[3:7])[:, 1:]
    H_mod_sym[States.ECEF_ORIENTATION.stop:, States.ECEF_ORIENTATION_ERR.stop:] = np.eye(dim_state - States.ECEF_ORIENTATION.stop)

    # these error functions are defined so that say there
    # is a nominal x and true x:
    # true x = err_function(nominal x, delta x)
    # delta x = inv_err_function(nominal x, true x)
    nom_x = sp.MatrixSymbol('nom_x', dim_state, 1)
    true_x = sp.MatrixSymbol('true_x', dim_state, 1)
    delta_x = sp.MatrixSymbol('delta_x', dim_state_err, 1)

    err_function_sym = sp.Matrix(np.zeros((dim_state, 1)))
    delta_quat = sp.Matrix(np.ones((4)))
    delta_quat[1:, :] = sp.Matrix(0.5 * delta_x[States.ECEF_ORIENTATION_ERR, :])
    err_function_sym[States.ECEF_POS, :] = sp.Matrix(nom_x[States.ECEF_POS, :] + delta_x[States.ECEF_POS_ERR, :])
    err_function_sym[States.ECEF_ORIENTATION, 0] = quat_matrix_r(nom_x[States.ECEF_ORIENTATION, 0]) * delta_quat
    err_function_sym[States.ECEF_ORIENTATION.stop:, :] = sp.Matrix(nom_x[States.ECEF_ORIENTATION.stop:, :] + delta_x[States.ECEF_ORIENTATION_ERR.stop:, :])

    inv_err_function_sym = sp.Matrix(np.zeros((dim_state_err, 1)))
    inv_err_function_sym[States.ECEF_POS_ERR, 0] = sp.Matrix(-nom_x[States.ECEF_POS, 0] + true_x[States.ECEF_POS, 0])
    delta_quat = quat_matrix_r(nom_x[States.ECEF_ORIENTATION, 0]).T * true_x[States.ECEF_ORIENTATION, 0]
    inv_err_function_sym[States.ECEF_ORIENTATION_ERR, 0] = sp.Matrix(2 * delta_quat[1:])
    inv_err_function_sym[States.ECEF_ORIENTATION_ERR.stop:, 0] = sp.Matrix(-nom_x[States.ECEF_ORIENTATION.stop:, 0] + true_x[States.ECEF_ORIENTATION.stop:, 0])

    eskf_params = [[err_function_sym, nom_x, delta_x],
                   [inv_err_function_sym, nom_x, true_x],
                   H_mod_sym, f_err_sym, state_err_sym]
    #
    # Observation functions
    #
    imu_rot = euler_rotate(*imu_angles)
    h_gyro_sym = imu_rot * sp.Matrix([vroll + roll_bias,
                                      vpitch + pitch_bias,
                                      vyaw + yaw_bias])

    pos = sp.Matrix([x, y, z])
    gravity = quat_rot.T * ((EARTH_GM / ((x**2 + y**2 + z**2)**(3.0 / 2.0))) * pos)
    h_acc_sym = imu_rot * (gravity + acceleration)
    h_phone_rot_sym = sp.Matrix([vroll, vpitch, vyaw])

    speed = sp.sqrt(vx**2 + vy**2 + vz**2)
    h_speed_sym = sp.Matrix([speed * odo_scale])

    h_pos_sym = sp.Matrix([x, y, z])
    h_imu_frame_sym = sp.Matrix(imu_angles)

    h_relative_motion = sp.Matrix(quat_rot.T * v)

    obs_eqs = [[h_speed_sym, ObservationKind.ODOMETRIC_SPEED, None],
               [h_gyro_sym, ObservationKind.PHONE_GYRO, None],
               [h_phone_rot_sym, ObservationKind.NO_ROT, None],
               [h_acc_sym, ObservationKind.PHONE_ACCEL, None],
               [h_pos_sym, ObservationKind.ECEF_POS, None],
               [h_relative_motion, ObservationKind.CAMERA_ODO_TRANSLATION, None],
               [h_phone_rot_sym, ObservationKind.CAMERA_ODO_ROTATION, None],
               [h_imu_frame_sym, ObservationKind.IMU_FRAME, None]]

    gen_code(name, f_sym, dt, state_sym, obs_eqs, dim_state, dim_state_err, eskf_params)