#!/usr/bin/env python
import sys,tty,termios
import datetime
import time
import dateutil.parser
import filenames
from select import select
from car import Car
import Adafruit_CharLCD as LCD
folder = 'recordings'
prefix = 'recording'
suffix = '.csv'
recording_file_path = filenames.next_filename(folder=folder,prefix=prefix,suffix=suffix)
def write_command_to_car(s):
command = open('/dev/car','w')
command.write(s)
def getch():
import sys, tty, termios
fd = sys.stdin.fileno()
old_settings = termios.tcgetattr(fd)
try:
tty.setraw(sys.stdin.fileno())
ch = sys.stdin.read(1)
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
return ch
def calibrate_braking(test_esc=1350,max_speed=1.,total_track_length=3.,stop_track_length=2.,note='na'):
run_track_length = total_track_length - stop_track_length
car = Car()
time.sleep(0.5)
car.zero_odometer()
car.set_rc_mode();
goal_heading = car.heading_degrees()
# accelerate in straight line until you get to desired speed
print ('accelerating to speed of '+str(max_speed))
v = 0.0 # assume we start at zero speed
aborted = False
while v < max_speed:
if car.odometer_meters() > run_track_length:
aborted = True
abort_reason = "ran out of track"
break;
esc = car.esc_for_velocity(v+2.5)
steer = car.steering_for_goal_heading_degrees(goal_heading)
car.set_esc_and_str(esc,steer)
time.sleep(0.02)
v = car.get_velocity_meters_per_second()
print('done accelerating at {:4.1f} meters'.format(car.odometer_meters()))
print('testing at esc: {}'.format(test_esc))
queue = Queue.Queue()
car.add_listener(queue)
data = []
# set the esc to given test setting
while True:
# go straight and record data until one of three things happens
esc = test_esc
steer = car.steering_for_goal_heading_degrees(goal_heading)
car.set_esc_and_str(esc,steer)
message = queue.get(block=True, timeout = 0.05)
data.append(message)
#
# 1. You come to a full stop
v = car.get_velocity_meters_per_second()
if v <= 0.:
print('test concluded at velocity zero')
break
# 2. Your speed stabilizes
# 3. You reach distance limit
if car.odometer_meters() > run_track_length:
print('test length exceeded, allowing room to stop')
break
# 4. You detect that you are skidding
car.remove_listener(queue)
if v > 0:
print('applying safety brake at {} meters and velocity {}'.format(car.odometer_meters(), v))
# put on "safe level" of brakes until your speed reaches zero (or negative)
while v > 0:
esc = 1350
steer = car.steering_for_goal_heading_degrees(goal_heading)
car.set_esc_and_str(esc,steer)
time.sleep(0.02)
v = car.get_velocity_meters_per_second()
# set everything to neutral
final_distance = car.odometer_meters()
print('final distance: {} meters'.format(final_distance))
car.set_manual_mode()
# save the results of braking to two files
# car dynamics in one file
# test settings in another file
# do a quick analysis of data and print results
prefix = 'esc/{}_start_{}_esc_{}'.format(note,int(max_speed*10),int(test_esc))
f = open(next_filename(folder = 'data', prefix = prefix, suffix = '.csv'), 'w')
print ('seconds,meters,us,esc,odometer_ticks,odometer_last_us,ax,spur_delta_us,spur_odo',file=f)
for p in data:
p.seconds = (p.us-data[0].us)/1000000.
p.meters = (p.odometer_ticks-data[0].odometer_ticks)*car.meters_per_odometer_tick
fields = [p.seconds,p.meters,p.us,p.esc,p.odometer_ticks,p.odometer_last_us,p.ax,p.spur_delta_us,p.spur_odo]
print(",".join([str(field) for field in fields]), file=f)
print('np polyfit 2 result',np.polyfit([p.seconds for p in data], [p.meters for p in data], 2))
print('np polyfit 3 result',np.polyfit([p.seconds for p in data], [p.meters for p in data], 3))
# distance to stop from speed, distance left in track
# whether skidding occurred
# estimate of acceleration using linear fit
# estimate of acceleration using polynomial fit (TBD: model for this, probably adding k*v^2 term for wind resistance)
car.reset_odometry()
time.sleep(0.01)
route = reverse_route(final_distance, max_a=0.5, max_v=2.)
play_route(route, car = car)
car.set_manual_mode()