openpilot/selfdrive/locationd/models/live_kf.py

246 lines
11 KiB
Python
Executable File

#!/usr/bin/env python3
import sys
import os
import numpy as np
from selfdrive.locationd.models.constants import ObservationKind
import sympy as sp
import inspect
from rednose.helpers.sympy_helpers import euler_rotate, quat_matrix_r, quat_rotate
from rednose.helpers.ekf_sym import gen_code
EARTH_GM = 3.986005e14 # m^3/s^2 (gravitational constant * mass of earth)
def numpy2eigenstring(arr):
assert(len(arr.shape) == 1)
arr_str = np.array2string(arr, precision=20, separator=',')[1:-1].replace(' ', '').replace('\n', '')
return f"(Eigen::VectorXd({len(arr)}) << {arr_str}).finished()"
class States():
ECEF_POS = slice(0, 3) # x, y and z in ECEF in meters
ECEF_ORIENTATION = slice(3, 7) # quat for pose of phone in ecef
ECEF_VELOCITY = slice(7, 10) # ecef velocity in m/s
ANGULAR_VELOCITY = slice(10, 13) # roll, pitch and yaw rates in device frame in radians/s
GYRO_BIAS = slice(13, 16) # roll, pitch and yaw biases
ODO_SCALE = slice(16, 17) # odometer scale
ACCELERATION = slice(17, 20) # Acceleration in device frame in m/s**2
IMU_OFFSET = slice(20, 23) # imu offset angles in radians
# Error-state has different slices because it is an ESKF
ECEF_POS_ERR = slice(0, 3)
ECEF_ORIENTATION_ERR = slice(3, 6) # euler angles for orientation error
ECEF_VELOCITY_ERR = slice(6, 9)
ANGULAR_VELOCITY_ERR = slice(9, 12)
GYRO_BIAS_ERR = slice(12, 15)
ODO_SCALE_ERR = slice(15, 16)
ACCELERATION_ERR = slice(16, 19)
IMU_OFFSET_ERR = slice(19, 22)
class LiveKalman():
name = 'live'
initial_x = np.array([-2.7e6, 4.2e6, 3.8e6,
1, 0, 0, 0,
0, 0, 0,
0, 0, 0,
0, 0, 0,
1,
0, 0, 0,
0, 0, 0])
# state covariance
initial_P_diag = np.array([1e16, 1e16, 1e16,
10**2, 10**2, 10**2,
10**2, 10**2, 10**2,
1**2, 1**2, 1**2,
0.05**2, 0.05**2, 0.05**2,
0.02**2,
1**2, 1**2, 1**2,
(0.01)**2, (0.01)**2, (0.01)**2])
# process noise
Q_diag = np.array([0.03**2, 0.03**2, 0.03**2,
0.001**2, 0.001**2, 0.001**2,
0.01**2, 0.01**2, 0.01**2,
0.1**2, 0.1**2, 0.1**2,
(0.005 / 100)**2, (0.005 / 100)**2, (0.005 / 100)**2,
(0.02 / 100)**2,
3**2, 3**2, 3**2,
(0.05 / 60)**2, (0.05 / 60)**2, (0.05 / 60)**2])
obs_noise_diag = {ObservationKind.ODOMETRIC_SPEED: np.array([0.2**2]),
ObservationKind.PHONE_GYRO: np.array([0.025**2, 0.025**2, 0.025**2]),
ObservationKind.PHONE_ACCEL: np.array([.5**2, .5**2, .5**2]),
ObservationKind.CAMERA_ODO_ROTATION: np.array([0.05**2, 0.05**2, 0.05**2]),
ObservationKind.IMU_FRAME: np.array([0.05**2, 0.05**2, 0.05**2]),
ObservationKind.NO_ROT: np.array([0.005**2, 0.005**2, 0.005**2]),
ObservationKind.ECEF_POS: np.array([5**2, 5**2, 5**2]),
ObservationKind.ECEF_VEL: np.array([.5**2, .5**2, .5**2]),
ObservationKind.ECEF_ORIENTATION_FROM_GPS: np.array([.2**2, .2**2, .2**2, .2**2])}
@staticmethod
def generate_code(generated_dir):
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 = 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 = (gravity + acceleration)
h_phone_rot_sym = sp.Matrix([vroll, vpitch, vyaw])
speed = sp.sqrt(vx**2 + vy**2 + vz**2 + 1e-6)
h_speed_sym = sp.Matrix([speed * odo_scale])
h_pos_sym = sp.Matrix([x, y, z])
h_vel_sym = sp.Matrix([vx, vy, vz])
h_orientation_sym = q
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_vel_sym, ObservationKind.ECEF_VEL, None],
[h_orientation_sym, ObservationKind.ECEF_ORIENTATION_FROM_GPS, 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]]
# this returns a sympy routine for the jacobian of the observation function of the local vel
in_vec = sp.MatrixSymbol('in_vec', 6, 1) # roll, pitch, yaw, vx, vy, vz
h = euler_rotate(in_vec[0], in_vec[1], in_vec[2]).T*(sp.Matrix([in_vec[3], in_vec[4], in_vec[5]]))
extra_routines = [('H', h.jacobian(in_vec), [in_vec])]
gen_code(generated_dir, name, f_sym, dt, state_sym, obs_eqs, dim_state, dim_state_err, eskf_params, extra_routines=extra_routines)
# write constants to extra header file for use in cpp
live_kf_header = "#pragma once\n\n"
live_kf_header += "#include <unordered_map>\n"
live_kf_header += "#include <eigen3/Eigen/Dense>\n\n"
for state, slc in inspect.getmembers(States, lambda x: type(x) == slice):
assert(slc.step is None) # unsupported
live_kf_header += f'#define STATE_{state}_START {slc.start}\n'
live_kf_header += f'#define STATE_{state}_END {slc.stop}\n'
live_kf_header += f'#define STATE_{state}_LEN {slc.stop - slc.start}\n'
live_kf_header += "\n"
for kind, val in inspect.getmembers(ObservationKind, lambda x: type(x) == int):
live_kf_header += f'#define OBSERVATION_{kind} {val}\n'
live_kf_header += "\n"
live_kf_header += f"static const Eigen::VectorXd live_initial_x = {numpy2eigenstring(LiveKalman.initial_x)};\n"
live_kf_header += f"static const Eigen::VectorXd live_initial_P_diag = {numpy2eigenstring(LiveKalman.initial_P_diag)};\n"
live_kf_header += f"static const Eigen::VectorXd live_Q_diag = {numpy2eigenstring(LiveKalman.Q_diag)};\n"
live_kf_header += "static const std::unordered_map<int, Eigen::Matrix<double, Eigen::Dynamic, Eigen::Dynamic, Eigen::RowMajor>> live_obs_noise_diag = {\n"
for kind, noise in LiveKalman.obs_noise_diag.items():
live_kf_header += f" {{ {kind}, {numpy2eigenstring(noise)} }},\n"
live_kf_header += "};\n\n"
open(os.path.join(generated_dir, "live_kf_constants.h"), 'w').write(live_kf_header)
if __name__ == "__main__":
generated_dir = sys.argv[2]
LiveKalman.generate_code(generated_dir)