ardupilot/Tools/autotest/pysim/util.py

451 lines
13 KiB
Python

import math
from math import sqrt, acos, cos, pi, sin, atan2
import os, sys, time, random
from rotmat import Vector3, Matrix3
from subprocess import call, check_call,Popen, PIPE
def m2ft(x):
'''meters to feet'''
return float(x) / 0.3048
def ft2m(x):
'''feet to meters'''
return float(x) * 0.3048
def kt2mps(x):
return x * 0.514444444
def mps2kt(x):
return x / 0.514444444
def topdir():
'''return top of git tree where autotest is running from'''
d = os.path.dirname(os.path.realpath(__file__))
assert(os.path.basename(d)=='pysim')
d = os.path.dirname(d)
assert(os.path.basename(d)=='autotest')
d = os.path.dirname(d)
assert(os.path.basename(d)=='Tools')
d = os.path.dirname(d)
return d
def reltopdir(path):
'''return a path relative to topdir()'''
return os.path.normpath(os.path.join(topdir(), path))
def run_cmd(cmd, dir=".", show=False, output=False, checkfail=True):
'''run a shell command'''
if show:
print("Running: '%s' in '%s'" % (cmd, dir))
if output:
return Popen([cmd], shell=True, stdout=PIPE, cwd=dir).communicate()[0]
elif checkfail:
return check_call(cmd, shell=True, cwd=dir)
else:
return call(cmd, shell=True, cwd=dir)
def rmfile(path):
'''remove a file if it exists'''
try:
os.unlink(path)
except Exception:
pass
def deltree(path):
'''delete a tree of files'''
run_cmd('rm -rf %s' % path)
def build_SIL(atype, target='sitl', j=1):
'''build desktop SIL'''
run_cmd("make clean",
dir=reltopdir(atype),
checkfail=True)
run_cmd("make -j%u %s" % (j, target),
dir=reltopdir(atype),
checkfail=True)
return True
# list of pexpect children to close on exit
close_list = []
def pexpect_autoclose(p):
'''mark for autoclosing'''
global close_list
close_list.append(p)
def pexpect_close(p):
'''close a pexpect child'''
global close_list
try:
p.close()
except Exception:
pass
try:
p.close(force=True)
except Exception:
pass
if p in close_list:
close_list.remove(p)
def pexpect_close_all():
'''close all pexpect children'''
global close_list
for p in close_list[:]:
pexpect_close(p)
def pexpect_drain(p):
'''drain any pending input'''
import pexpect
try:
p.read_nonblocking(1000, timeout=0)
except pexpect.TIMEOUT:
pass
def start_SIL(atype, valgrind=False, wipe=False, synthetic_clock=True, home=None, model=None, speedup=1):
'''launch a SIL instance'''
import pexpect
cmd=""
if valgrind and os.path.exists('/usr/bin/valgrind'):
cmd += 'valgrind -q --log-file=%s-valgrind.log ' % atype
executable = reltopdir('tmp/%s.build/%s.elf' % (atype, atype))
if not os.path.exists(executable):
executable = '/tmp/%s.build/%s.elf' % (atype, atype)
cmd += executable
if wipe:
cmd += ' -w'
if synthetic_clock:
cmd += ' -S'
if home is not None:
cmd += ' --home=%s' % home
if model is not None:
cmd += ' --model=%s' % model
if speedup != 1:
cmd += ' --speedup=%f' % speedup
print("Running: %s" % cmd)
ret = pexpect.spawn(cmd, logfile=sys.stdout, timeout=5)
ret.delaybeforesend = 0
pexpect_autoclose(ret)
ret.expect('Waiting for connection')
return ret
def start_MAVProxy_SIL(atype, aircraft=None, setup=False, master='tcp:127.0.0.1:5760',
options=None, logfile=sys.stdout):
'''launch mavproxy connected to a SIL instance'''
import pexpect
global close_list
MAVPROXY = os.getenv('MAVPROXY_CMD', 'mavproxy.py')
cmd = MAVPROXY + ' --master=%s --out=127.0.0.1:14550' % master
if setup:
cmd += ' --setup'
if aircraft is None:
aircraft = 'test.%s' % atype
cmd += ' --aircraft=%s' % aircraft
if options is not None:
cmd += ' ' + options
ret = pexpect.spawn(cmd, logfile=logfile, timeout=60)
ret.delaybeforesend = 0
pexpect_autoclose(ret)
return ret
def expect_setup_callback(e, callback):
'''setup a callback that is called once a second while waiting for
patterns'''
import pexpect
def _expect_callback(pattern, timeout=e.timeout):
tstart = time.time()
while time.time() < tstart + timeout:
try:
ret = e.expect_saved(pattern, timeout=1)
return ret
except pexpect.TIMEOUT:
e.expect_user_callback(e)
pass
print("Timed out looking for %s" % pattern)
raise pexpect.TIMEOUT(timeout)
e.expect_user_callback = callback
e.expect_saved = e.expect
e.expect = _expect_callback
def mkdir_p(dir):
'''like mkdir -p'''
if not dir:
return
if dir.endswith("/"):
mkdir_p(dir[:-1])
return
if os.path.isdir(dir):
return
mkdir_p(os.path.dirname(dir))
os.mkdir(dir)
def loadfile(fname):
'''load a file as a string'''
f = open(fname, mode='r')
r = f.read()
f.close()
return r
def lock_file(fname):
'''lock a file'''
import fcntl
f = open(fname, mode='w')
try:
fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
except Exception:
return None
return f
def check_parent(parent_pid=None):
'''check our parent process is still alive'''
if parent_pid is None:
try:
parent_pid = os.getppid()
except Exception:
pass
if parent_pid is None:
return
try:
os.kill(parent_pid, 0)
except Exception:
print("Parent had finished - exiting")
sys.exit(1)
def EarthRatesToBodyRates(dcm, earth_rates):
'''convert the angular velocities from earth frame to
body frame. Thanks to James Goppert for the formula
all inputs and outputs are in radians
returns a gyro vector in body frame, in rad/s
'''
from math import sin, cos
(phi, theta, psi) = dcm.to_euler()
phiDot = earth_rates.x
thetaDot = earth_rates.y
psiDot = earth_rates.z
p = phiDot - psiDot*sin(theta)
q = cos(phi)*thetaDot + sin(phi)*psiDot*cos(theta)
r = cos(phi)*psiDot*cos(theta) - sin(phi)*thetaDot
return Vector3(p, q, r)
def BodyRatesToEarthRates(dcm, gyro):
'''convert the angular velocities from body frame to
earth frame.
all inputs and outputs are in radians/s
returns a earth rate vector
'''
from math import sin, cos, tan, fabs
p = gyro.x
q = gyro.y
r = gyro.z
(phi, theta, psi) = dcm.to_euler()
phiDot = p + tan(theta)*(q*sin(phi) + r*cos(phi))
thetaDot = q*cos(phi) - r*sin(phi)
if fabs(cos(theta)) < 1.0e-20:
theta += 1.0e-10
psiDot = (q*sin(phi) + r*cos(phi))/cos(theta)
return Vector3(phiDot, thetaDot, psiDot)
radius_of_earth = 6378100.0 # in meters
def gps_newpos(lat, lon, bearing, distance):
'''extrapolate latitude/longitude given a heading and distance
thanks to http://www.movable-type.co.uk/scripts/latlong.html
'''
from math import sin, asin, cos, atan2, radians, degrees
lat1 = radians(lat)
lon1 = radians(lon)
brng = radians(bearing)
dr = distance/radius_of_earth
lat2 = asin(sin(lat1)*cos(dr) +
cos(lat1)*sin(dr)*cos(brng))
lon2 = lon1 + atan2(sin(brng)*sin(dr)*cos(lat1),
cos(dr)-sin(lat1)*sin(lat2))
return (degrees(lat2), degrees(lon2))
def gps_distance(lat1, lon1, lat2, lon2):
'''return distance between two points in meters,
coordinates are in degrees
thanks to http://www.movable-type.co.uk/scripts/latlong.html'''
lat1 = math.radians(lat1)
lat2 = math.radians(lat2)
lon1 = math.radians(lon1)
lon2 = math.radians(lon2)
dLat = lat2 - lat1
dLon = lon2 - lon1
a = math.sin(0.5*dLat)**2 + math.sin(0.5*dLon)**2 * math.cos(lat1) * math.cos(lat2)
c = 2.0 * math.atan2(math.sqrt(a), math.sqrt(1.0-a))
return radius_of_earth * c
def gps_bearing(lat1, lon1, lat2, lon2):
'''return bearing between two points in degrees, in range 0-360
thanks to http://www.movable-type.co.uk/scripts/latlong.html'''
lat1 = math.radians(lat1)
lat2 = math.radians(lat2)
lon1 = math.radians(lon1)
lon2 = math.radians(lon2)
dLat = lat2 - lat1
dLon = lon2 - lon1
y = math.sin(dLon) * math.cos(lat2)
x = math.cos(lat1)*math.sin(lat2) - math.sin(lat1)*math.cos(lat2)*math.cos(dLon)
bearing = math.degrees(math.atan2(y, x))
if bearing < 0:
bearing += 360.0
return bearing
class Wind(object):
'''a wind generation object'''
def __init__(self, windstring, cross_section=0.1):
a = windstring.split(',')
if len(a) != 3:
raise RuntimeError("Expected wind in speed,direction,turbulance form, not %s" % windstring)
self.speed = float(a[0]) # m/s
self.direction = float(a[1]) # direction the wind is going in
self.turbulance= float(a[2]) # turbulance factor (standard deviation)
# the cross-section of the aircraft to wind. This is multiplied by the
# difference in the wind and the velocity of the aircraft to give the acceleration
self.cross_section = cross_section
# the time constant for the turbulance - the average period of the
# changes over time
self.turbulance_time_constant = 5.0
# wind time record
self.tlast = time.time()
# initial turbulance multiplier
self.turbulance_mul = 1.0
def current(self, deltat=None):
'''return current wind speed and direction as a tuple
speed is in m/s, direction in degrees
'''
if deltat is None:
tnow = time.time()
deltat = tnow - self.tlast
self.tlast = tnow
# update turbulance random walk
w_delta = math.sqrt(deltat)*(1.0-random.gauss(1.0, self.turbulance))
w_delta -= (self.turbulance_mul-1.0)*(deltat/self.turbulance_time_constant)
self.turbulance_mul += w_delta
speed = self.speed * math.fabs(self.turbulance_mul)
return (speed, self.direction)
# Calculate drag.
def drag(self, velocity, deltat=None, testing=None):
'''return current wind force in Earth frame. The velocity parameter is
a Vector3 of the current velocity of the aircraft in earth frame, m/s'''
from math import radians
# (m/s, degrees) : wind vector as a magnitude and angle.
(speed, direction) = self.current(deltat=deltat)
# speed = self.speed
# direction = self.direction
# Get the wind vector.
w = toVec(speed, radians(direction))
obj_speed = velocity.length()
# Compute the angle between the object vector and wind vector by taking
# the dot product and dividing by the magnitudes.
d = w.length() * obj_speed
if d == 0:
alpha = 0
else:
alpha = acos((w * velocity) / d)
# Get the relative wind speed and angle from the object. Note that the
# relative wind speed includes the velocity of the object; i.e., there
# is a headwind equivalent to the object's speed even if there is no
# absolute wind.
(rel_speed, beta) = apparent_wind(speed, obj_speed, alpha)
# Return the vector of the relative wind, relative to the coordinate
# system.
relWindVec = toVec(rel_speed, beta + atan2(velocity.y, velocity.x))
# Combine them to get the acceleration vector.
return Vector3( acc(relWindVec.x, drag_force(self, relWindVec.x))
, acc(relWindVec.y, drag_force(self, relWindVec.y))
, 0 )
# http://en.wikipedia.org/wiki/Apparent_wind
#
# Returns apparent wind speed and angle of apparent wind. Alpha is the angle
# between the object and the true wind. alpha of 0 rads is a headwind; pi a
# tailwind. Speeds should always be positive.
def apparent_wind(wind_sp, obj_speed, alpha):
delta = wind_sp * cos(alpha)
x = wind_sp**2 + obj_speed**2 + 2 * obj_speed * delta
rel_speed = sqrt(x)
if rel_speed == 0:
beta = pi
else:
beta = acos((delta + obj_speed) / rel_speed)
return (rel_speed, beta)
# See http://en.wikipedia.org/wiki/Drag_equation
#
# Drag equation is F(a) = cl * p/2 * v^2 * a, where cl : drag coefficient
# (let's assume it's low, .e.g., 0.2), p : density of air (assume about 1
# kg/m^3, the density just over 1500m elevation), v : relative speed of wind
# (to the body), a : area acted on (this is captured by the cross_section
# paramter).
#
# So then we have
# F(a) = 0.2 * 1/2 * v^2 * cross_section = 0.1 * v^2 * cross_section
def drag_force(wind, sp):
return (sp**2.0) * 0.1 * wind.cross_section
# Function to make the force vector. relWindVec is the direction the apparent
# wind comes *from*. We want to compute the accleration vector in the direction
# the wind blows to.
def acc(val, mag):
if val == 0:
return mag
else:
return (val / abs(val)) * (0 - mag)
# Converts a magnitude and angle (radians) to a vector in the xy plane.
def toVec(magnitude, angle):
v = Vector3(magnitude, 0, 0)
m = Matrix3()
m.from_euler(0, 0, angle)
return m.transposed() * v
def constrain(value, minv, maxv):
'''constrain a value to a range'''
if value < minv:
value = minv
if value > maxv:
value = maxv
return value
if __name__ == "__main__":
import doctest
doctest.testmod()