openpilot is an open source driver assistance system. openpilot performs the functions of Automated Lane Centering and Adaptive Cruise Control for over 200 supported car makes and models.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

72 lines
2.4 KiB

import numpy as np
from selfdrive.controls.lib.drive_helpers import get_steer_max
from common.numpy_fast import clip
from cereal import log
class LatControlLQR(object):
def __init__(self, CP, rate=100):
self.sat_flag = False
self.scale = CP.lateralTuning.lqr.scale
self.ki = CP.lateralTuning.lqr.ki
self.A = np.array(CP.lateralTuning.lqr.a).reshape((2,2))
self.B = np.array(CP.lateralTuning.lqr.b).reshape((2,1))
self.C = np.array(CP.lateralTuning.lqr.c).reshape((1,2))
self.K = np.array(CP.lateralTuning.lqr.k).reshape((1,2))
self.L = np.array(CP.lateralTuning.lqr.l).reshape((2,1))
self.dc_gain = CP.lateralTuning.lqr.dcGain
self.x_hat = np.array([[0], [0]])
self.i_unwind_rate = 0.3 / rate
self.i_rate = 1.0 / rate
self.reset()
def reset(self):
self.i_lqr = 0.0
self.output_steer = 0.0
def update(self, active, v_ego, angle_steers, angle_steers_rate, eps_torque, steer_override, CP, VM, path_plan):
lqr_log = log.ControlsState.LateralLQRState.new_message()
torque_scale = (0.45 + v_ego / 60.0)**2 # Scale actuator model with speed
# Subtract offset. Zero angle should correspond to zero torque
self.angle_steers_des = path_plan.angleSteers - path_plan.angleOffset
angle_steers -= path_plan.angleOffset
# Update Kalman filter
angle_steers_k = float(self.C.dot(self.x_hat))
e = angle_steers - angle_steers_k
self.x_hat = self.A.dot(self.x_hat) + self.B.dot(eps_torque / torque_scale) + self.L.dot(e)
if v_ego < 0.3 or not active:
lqr_log.active = False
self.reset()
else:
lqr_log.active = True
# LQR
u_lqr = float(self.angle_steers_des / self.dc_gain - self.K.dot(self.x_hat))
# Integrator
if steer_override:
self.i_lqr -= self.i_unwind_rate * float(np.sign(self.i_lqr))
else:
self.i_lqr += self.ki * self.i_rate * (self.angle_steers_des - angle_steers_k)
lqr_output = torque_scale * u_lqr / self.scale
self.i_lqr = clip(self.i_lqr, -1.0 - lqr_output, 1.0 - lqr_output) # (LQR + I) has to be between -1 and 1
self.output_steer = lqr_output + self.i_lqr
# Clip output
steers_max = get_steer_max(CP, v_ego)
self.output_steer = clip(self.output_steer, -steers_max, steers_max)
lqr_log.steerAngle = angle_steers_k + path_plan.angleOffset
lqr_log.i = self.i_lqr
lqr_log.output = self.output_steer
return self.output_steer, float(self.angle_steers_des), lqr_log