Tools: improve tempcal script

- allow display of log corrections
 - added online estimator
 - allow learning using TCLR records
This commit is contained in:
Andrew Tridgell 2021-01-16 09:53:59 +11:00 committed by Peter Barker
parent 30385fb8cb
commit e8ab8ed29e
1 changed files with 341 additions and 145 deletions

View File

@ -5,8 +5,11 @@ Create temperature calibration parameters for IMUs based on log data.
from argparse import ArgumentParser from argparse import ArgumentParser
parser = ArgumentParser(description=__doc__) parser = ArgumentParser(description=__doc__)
parser.add_argument("--outfile", default="tcal.parm") parser.add_argument("--outfile", default="tcal.parm", help='set output file')
parser.add_argument("--no-graph", action='store_true', default=False) parser.add_argument("--no-graph", action='store_true', default=False, help='disable graph display')
parser.add_argument("--log-parm", action='store_true', default=False, help='show corrections using coefficients from log file')
parser.add_argument("--online", action='store_true', default=False, help='use online polynomial fitting')
parser.add_argument("--tclr", action='store_true', default=False, help='use TCLR messages from log instead of IMU messages')
parser.add_argument("log", metavar="LOG") parser.add_argument("log", metavar="LOG")
args = parser.parse_args() args = parser.parse_args()
@ -27,11 +30,201 @@ POLY_ORDER = 3
# use exponential notation # use exponential notation
SCALE_FACTOR = 1.0e6 SCALE_FACTOR = 1.0e6
def moving_average(data, w): AXES = ['X','Y','Z']
'''apply a moving average filter over a window of width w''' AXEST = ['X','Y','Z','T','time']
ret = np.cumsum(data)
ret[w:] = ret[w:] - ret[:-w] class Coefficients:
return ret[w - 1:] / w '''class representing a set of coefficients'''
def __init__(self):
self.acoef = {}
self.gcoef = {}
self.enable = [0]*3
self.tmin = [-100]*3
self.tmax = [-100]*3
self.gtcal = {}
self.atcal = {}
def set_accel_poly(self, imu, axis, values):
if not imu in self.acoef:
self.acoef[imu] = {}
if not axis in self.acoef[imu]:
self.acoef[imu][axis] = [0]*4
self.acoef[imu][axis] = values
def set_gyro_poly(self, imu, axis, values):
if not imu in self.gcoef:
self.gcoef[imu] = {}
if not axis in self.gcoef[imu]:
self.gcoef[imu][axis] = [0]*4
self.gcoef[imu][axis] = values
def set_acoeff(self, imu, axis, order, value):
if not imu in self.acoef:
self.acoef[imu] = {}
if not axis in self.acoef[imu]:
self.acoef[imu][axis] = [0]*4
self.acoef[imu][axis][POLY_ORDER-order] = value
def set_gcoeff(self, imu, axis, order, value):
if not imu in self.gcoef:
self.gcoef[imu] = {}
if not axis in self.gcoef[imu]:
self.gcoef[imu][axis] = [0]*4
self.gcoef[imu][axis][POLY_ORDER-order] = value
def set_tmin(self, imu, tmin):
self.tmin[imu] = tmin
def set_tmax(self, imu, tmax):
self.tmax[imu] = tmax
def set_gyro_tcal(self, imu, value):
self.gtcal[imu] = value
def set_accel_tcal(self, imu, value):
self.atcal[imu] = value
def set_enable(self, imu, value):
self.enable[imu] = value
def correction(self, coeff, imu, temperature, axis):
'''calculate correction from temperature calibration from log data using parameters'''
if self.enable[imu] != 1.0:
return 0.0
tmid = 0.5 * (self.tmax[imu] + self.tmin[imu])
if tmid <= 0:
return 0.0
if self.atcal[imu] <= -80:
return 0.0
if not axis in coeff:
return 0.0
temperature = constrain(temperature, self.tmin[imu], self.tmax[imu])
cal_temp = constrain(self.atcal[imu], self.tmin[imu], self.tmax[imu])
poly = np.poly1d(coeff[axis])
ret = poly(self.atcal[imu] - tmid) - poly(temperature-tmid)
return ret
def correction_accel(self, imu, temperature):
'''calculate accel correction from temperature calibration from
log data using parameters'''
return Vector3(self.correction(self.acoef[imu], imu, temperature, 'X'),
self.correction(self.acoef[imu], imu, temperature, 'Y'),
self.correction(self.acoef[imu], imu, temperature, 'Z'))
def correction_gyro(self, imu, temperature):
'''calculate gyro correction from temperature calibration from
log data using parameters'''
return Vector3(self.correction(self.gcoef[imu], imu, temperature, 'X'),
self.correction(self.gcoef[imu], imu, temperature, 'Y'),
self.correction(self.gcoef[imu], imu, temperature, 'Z'))
def param_string(self, imu):
params = ''
params += 'INS_TCAL%u_ENABLE 1\n' % (imu+1)
params += 'INS_TCAL%u_TMIN %.1f\n' % (imu+1, self.tmin[imu])
params += 'INS_TCAL%u_TMAX %.1f\n' % (imu+1, self.tmax[imu])
# note that we don't save the first term of the polynomial as that is a
# constant offset which is already handled by the accel/gyro constant
# offsets. We only same the temperature dependent part of the
# calibration
for p in range(POLY_ORDER):
for axis in AXES:
params += 'INS_TCAL%u_ACC%u_%s %.9f\n' % (imu+1, p+1, axis, self.acoef[imu][axis][POLY_ORDER-(p+1)]*SCALE_FACTOR)
for p in range(POLY_ORDER):
for axis in AXES:
params += 'INS_TCAL%u_GYR%u_%s %.9f\n' % (imu+1, p+1, axis, self.gcoef[imu][axis][POLY_ORDER-(p+1)]*SCALE_FACTOR)
return params
class OnlineIMUfit:
'''implement the online learning used in ArduPilot'''
def __init__(self):
pass
def update(self, x, y):
temp = 1.0
for i in range(2*(self.porder - 1), -1, -1):
k = 0 if (i < self.porder) else (i - self.porder + 1)
for j in range(i - k, k-1, -1):
self.mat[j][i-j] += temp
temp *= x
temp = 1.0
for i in range(self.porder-1, -1, -1):
self.vec[i] += y * temp
temp *= x
def get_polynomial(self):
inv_mat = np.linalg.inv(self.mat)
res = np.zeros(self.porder)
for i in range(self.porder):
res[i] = 0.0
for j in range(self.porder):
res[i] += inv_mat[i][j] * self.vec[j]
return res
def polyfit(self, x, y, order):
self.porder = order + 1
self.mat = np.zeros((self.porder, self.porder))
self.vec = np.zeros(self.porder)
for i in range(len(x)):
self.update(x[i], y[i])
return self.get_polynomial()
class IMUData:
def __init__(self):
self.accel = {}
self.gyro = {}
def IMUs(self):
'''return list of IMUs'''
return self.accel.keys()
def add_accel(self, imu, temperature, time, value):
if not imu in self.accel:
self.accel[imu] = {}
for axis in AXEST:
self.accel[imu][axis] = np.zeros(0,dtype=float)
self.accel[imu]['T'] = np.append(self.accel[imu]['T'], temperature)
self.accel[imu]['X'] = np.append(self.accel[imu]['X'], value.x)
self.accel[imu]['Y'] = np.append(self.accel[imu]['Y'], value.y)
self.accel[imu]['Z'] = np.append(self.accel[imu]['Z'], value.z)
self.accel[imu]['time'] = np.append(self.accel[imu]['time'], time)
def add_gyro(self, imu, temperature, time, value):
if not imu in self.gyro:
self.gyro[imu] = {}
for axis in AXEST:
self.gyro[imu][axis] = np.zeros(0,dtype=float)
self.gyro[imu]['T'] = np.append(self.gyro[imu]['T'], temperature)
self.gyro[imu]['X'] = np.append(self.gyro[imu]['X'], value.x)
self.gyro[imu]['Y'] = np.append(self.gyro[imu]['Y'], value.y)
self.gyro[imu]['Z'] = np.append(self.gyro[imu]['Z'], value.z)
self.gyro[imu]['time'] = np.append(self.gyro[imu]['time'], time)
def moving_average(self, data, w):
'''apply a moving average filter over a window of width w'''
ret = np.cumsum(data)
ret[w:] = ret[w:] - ret[:-w]
return ret[w - 1:] / w
def FilterArray(self, data, width_s):
'''apply moving average filter of width width_s seconds'''
nseconds = data['time'][-1] - data['time'][0]
nsamples = len(data['time'])
window = int(nsamples / nseconds) * width_s
if window > 1:
for axis in AXEST:
data[axis] = self.moving_average(data[axis], window)
return data
def Filter(self, width_s):
'''apply moving average filter of width width_s seconds'''
for imu in self.IMUs():
self.accel[imu] = self.FilterArray(self.accel[imu], width_s)
self.gyro[imu] = self.FilterArray(self.gyro[imu], width_s)
def constrain(value, minv, maxv): def constrain(value, minv, maxv):
"""Constrain a value to a range.""" """Constrain a value to a range."""
@ -41,178 +234,160 @@ def constrain(value, minv, maxv):
value = maxv value = maxv
return value return value
def correction_parm(enable, tmin, tmax, coeff, temperature, cal_temp, axis):
'''calculate correction from temperature calibration from log data using parameters'''
if enable != 1.0:
return 0.0
tmid = 0.5 * (tmax + tmin)
if tmid <= 0:
return 0.0
if cal_temp <= -80:
return 0.0
if not axis in coeff:
return 0.0
temperature = constrain(temperature, tmin, tmax)
cal_temp = constrain(cal_temp, tmin, tmax)
poly = np.poly1d(coeff[axis])
ret = poly(cal_temp-tmid) - poly(temperature-tmid)
return ret
def IMUfit(logfile): def IMUfit(logfile):
'''find IMU calibration parameters from a log file''' '''find IMU calibration parameters from a log file'''
print("Processing log %s" % logfile) print("Processing log %s" % logfile)
mlog = mavutil.mavlink_connection(logfile) mlog = mavutil.mavlink_connection(logfile)
accel = {} data = IMUData()
gyro = {}
acoef = {} c = Coefficients()
gcoef = {}
enable = [0]*3
tmin = [-100]*3
tmax = [-100]*3
gtcal = {}
atcal = {}
orientation = 0 orientation = 0
axes = ['X','Y','Z']
axesT = ['X','Y','Z','T','time'] stop_capture = [ False ] * 3
if args.tclr:
messages = ['PARM','TCLR']
else:
messages = ['PARM','IMU']
while True: while True:
msg = mlog.recv_match(type=['IMU','PARM']) msg = mlog.recv_match(type=messages)
if msg is None: if msg is None:
break break
if msg.get_type() == 'PARM': if msg.get_type() == 'PARM':
# build up the old coefficients so we can remove the impact of # build up the old coefficients so we can remove the impact of
# existing coefficients from the data # existing coefficients from the data
m = re.match("^INS_TCAL(\d)_ENABLE$", msg.Name)
if m:
imu = int(m.group(1))-1
if stop_capture[imu]:
continue
if msg.Value == 1 and c.enable[imu] == 2:
print("TCAL[%u] enabled" % imu)
stop_capture[imu] = True
continue
if msg.Value == 0 and c.enable[imu] == 1:
print("TCAL[%u] disabled" % imu)
stop_capture[imu] = True
continue
c.set_enable(imu, msg.Value)
m = re.match("^INS_TCAL(\d)_([AG]..)([1-3])_([XYZ])$", msg.Name) m = re.match("^INS_TCAL(\d)_([AG]..)([1-3])_([XYZ])$", msg.Name)
if m: if m:
imu = int(m.group(1))-1 imu = int(m.group(1))-1
stype = m.group(2) stype = m.group(2)
p = int(m.group(3)) p = int(m.group(3))
axis = m.group(4) axis = m.group(4)
if stop_capture[imu]:
continue
if stype == 'ACC': if stype == 'ACC':
if not imu in acoef: c.set_acoeff(imu, axis, p, msg.Value/SCALE_FACTOR)
acoef[imu] = {}
if not axis in acoef[imu]:
acoef[imu][axis] = [0.0]*4
acoef[imu][axis][POLY_ORDER-p] = msg.Value/SCALE_FACTOR
if stype == 'GYR': if stype == 'GYR':
if not imu in gcoef: c.set_gcoeff(imu, axis, p, msg.Value/SCALE_FACTOR)
gcoef[imu] = {}
if not axis in gcoef[imu]:
gcoef[imu][axis] = [0.0]*4
gcoef[imu][axis][POLY_ORDER-p] = msg.Value/SCALE_FACTOR
m = re.match("^INS_TCAL(\d)_ENABLE$", msg.Name)
if m:
imu = int(m.group(1))-1
if msg.Value == 1 and enable[imu] == 2:
print("TCAL[%u] enabled" % imu)
break
enable[imu] = msg.Value
m = re.match("^INS_TCAL(\d)_TMIN$", msg.Name) m = re.match("^INS_TCAL(\d)_TMIN$", msg.Name)
if m: if m:
imu = int(m.group(1))-1 imu = int(m.group(1))-1
tmin[imu] = msg.Value if stop_capture[imu]:
continue
c.set_tmin(imu, msg.Value)
m = re.match("^INS_TCAL(\d)_TMAX", msg.Name) m = re.match("^INS_TCAL(\d)_TMAX", msg.Name)
if m: if m:
imu = int(m.group(1))-1 imu = int(m.group(1))-1
tmax[imu] = msg.Value if stop_capture[imu]:
continue
c.set_tmax(imu, msg.Value)
m = re.match("^INS_GYR_CALTEMP(\d)", msg.Name) m = re.match("^INS_GYR_CALTEMP(\d)", msg.Name)
if m: if m:
imu = int(m.group(1))-1 imu = int(m.group(1))-1
gtcal[imu] = msg.Value if stop_capture[imu]:
continue
c.set_gyro_tcal(imu, msg.Value)
m = re.match("^INS_ACC_CALTEMP(\d)", msg.Name) m = re.match("^INS_ACC_CALTEMP(\d)", msg.Name)
if m: if m:
imu = int(m.group(1))-1 imu = int(m.group(1))-1
atcal[imu] = msg.Value if stop_capture[imu]:
continue
c.set_accel_tcal(imu, msg.Value)
if msg.Name == 'AHRS_ORIENTATION': if msg.Name == 'AHRS_ORIENTATION':
orientation = int(msg.Value) orientation = int(msg.Value)
print("Using orientation %d" % orientation) print("Using orientation %d" % orientation)
if msg.get_type() != 'IMU': if msg.get_type() == 'TCLR' and args.tclr:
continue imu = msg.I
imu = msg.I T = msg.Temp
if msg.Si == 0:
# accel
acc = Vector3(msg.X, msg.Y, msg.Z)
time = msg.TimeUS*1.0e-6
data.add_accel(imu, T, time, acc)
elif msg.Si == 1:
# gyro
gyr = Vector3(msg.X, msg.Y, msg.Z)
time = msg.TimeUS*1.0e-6
data.add_gyro(imu, T, time, gyr)
if imu not in accel: if msg.get_type() == 'IMU' and not args.tclr:
accel[imu] = {} imu = msg.I
gyro[imu] = {}
for axis in axesT:
accel[imu][axis] = np.zeros(0,dtype=float)
gyro[imu][axis] = np.zeros(0,dtype=float)
T = msg.T T = msg.T
accel[imu]['T'] = np.append(accel[imu]['T'], T) acc = Vector3(msg.AccX, msg.AccY, msg.AccZ)
gyro[imu]['T'] = np.append(gyro[imu]['T'], T) gyr = Vector3(msg.GyrX, msg.GyrY, msg.GyrZ)
accel[imu]['time'] = np.append(accel[imu]['time'], msg.TimeUS*1.0e-6)
gyro[imu]['time'] = np.append(gyro[imu]['time'], msg.TimeUS*1.0e-6)
acc = Vector3(msg.AccX, msg.AccY, msg.AccZ) # invert the board orientation rotation. Corrections are in sensor frame
gyr = Vector3(msg.GyrX, msg.GyrY, msg.GyrZ) if orientation != 0:
acc = acc.rotate_by_inverse_id(orientation)
gyr = gyr.rotate_by_inverse_id(orientation)
if acc is None or gyr is None:
print("Invalid AHRS_ORIENTATION %u" % orientation)
sys.exit(1)
# invert the board orientation rotation. Corrections are in sensor frame if c.enable[imu] == 1:
if orientation != 0: acc -= c.correction_accel(imu, T)
acc = acc.rotate_by_inverse_id(orientation) gyr -= c.correction_gyro(imu, T)
gyr = gyr.rotate_by_inverse_id(orientation)
if acc is None or gyr is None:
print("Invalid AHRS_ORIENTATION %u" % orientation)
sys.exit(1)
for axis in axes: time = msg.TimeUS*1.0e-6
value = getattr(acc, axis.lower()) data.add_accel(imu, T, time, acc)
if enable[imu] == 1: data.add_gyro (imu, T, time, gyr)
value -= correction_parm(enable[imu], tmin[imu], tmax[imu], acoef[imu],
T, atcal[imu], axis)
accel[imu][axis] = np.append(accel[imu][axis], value)
value = getattr(gyr, axis.lower()) if len(data.IMUs()) == 0:
if enable[imu] == 1: print("No data found")
value -= correction_parm(enable[imu], tmin[imu], tmax[imu], gcoef[imu], sys.exit(1)
T, gtcal[imu], axis)
gyro[imu][axis] = np.append(gyro[imu][axis], value)
# apply moving average filter with 2s width print("Loaded %u accel and %u gyro samples" % (len(data.accel[0]['T']),len(data.gyro[0]['T'])))
for imu in accel:
nseconds = accel[imu]['time'][-1] - accel[imu]['time'][0]
nsamples = len(accel[imu]['time'])
window = int(nsamples / nseconds) * 2
for axis in axesT: if not args.tclr:
accel[imu][axis] = moving_average(accel[imu][axis], window) # apply moving average filter with 2s width
gyro[imu][axis] = moving_average(gyro[imu][axis], window) data.Filter(2)
trel = {} clog = c
c = Coefficients()
calfile = open(args.outfile, "w") calfile = open(args.outfile, "w")
for imu in accel: for imu in data.IMUs():
tmin = np.amin(accel[imu]['T']) tmin = np.amin(data.accel[imu]['T'])
tmax = np.amax(accel[imu]['T']) tmax = np.amax(data.accel[imu]['T'])
tref = (tmin+tmax)*0.5 tref = (tmin+tmax)*0.5
acoef[imu] = {} c.set_tmin(imu, tmin)
gcoef[imu] = {} c.set_tmax(imu, tmax)
trel[imu] = accel[imu]['T'] - tref for axis in AXES:
if args.online:
fit = OnlineIMUfit()
trel = data.accel[imu]['T'] - tref
c.set_accel_poly(imu, axis, fit.polyfit(trel, data.accel[imu][axis] - np.median(data.accel[imu][axis]), POLY_ORDER))
trel = data.gyro[imu]['T'] - tref
c.set_gyro_poly(imu, axis, fit.polyfit(trel, data.gyro[imu][axis], POLY_ORDER))
else:
trel = data.accel[imu]['T'] - tref
c.set_accel_poly(imu, axis, np.polyfit(trel, data.accel[imu][axis] - np.median(data.accel[imu][axis]), POLY_ORDER))
trel = data.gyro[imu]['T'] - tref
c.set_gyro_poly(imu, axis, np.polyfit(trel, data.gyro[imu][axis], POLY_ORDER))
for axis in axes: params = c.param_string(imu)
acoef[imu][axis] = np.polyfit(trel[imu], accel[imu][axis] - np.median(accel[imu][axis]), POLY_ORDER)
gcoef[imu][axis] = np.polyfit(trel[imu], gyro[imu][axis], POLY_ORDER)
params = ''
params += 'INS_TCAL%u_ENABLE 1\n' % (imu+1)
params += 'INS_TCAL%u_TMIN %.1f\n' % (imu+1, tmin)
params += 'INS_TCAL%u_TMAX %.1f\n' % (imu+1, tmax)
# note that we don't save the first term of the polynomial as that is a
# constant offset which is already handled by the accel/gyro constant
# offsets. We only same the temperature dependent part of the
# calibration
for p in range(POLY_ORDER):
for axis in axes:
params += 'INS_TCAL%u_ACC%u_%s %.9f\n' % (imu+1, p+1, axis, acoef[imu][axis][POLY_ORDER-(p+1)]*SCALE_FACTOR)
for p in range(POLY_ORDER):
for axis in axes:
params += 'INS_TCAL%u_GYR%u_%s %.9f\n' % (imu+1, p+1, axis, gcoef[imu][axis][POLY_ORDER-(p+1)]*SCALE_FACTOR)
print(params) print(params)
calfile.write(params) calfile.write(params)
@ -221,40 +396,61 @@ def IMUfit(logfile):
if args.no_graph: if args.no_graph:
return return
fig, axs = pyplot.subplots(len(gyro), 1, sharex=True) fig, axs = pyplot.subplots(len(data.IMUs()), 1, sharex=True)
if len(gyro) == 1: num_imus = len(data.IMUs())
if num_imus == 1:
axs = [axs] axs = [axs]
for imu in gyro: for imu in data.IMUs():
scale = math.degrees(1) scale = math.degrees(1)
for axis in axes: for axis in AXES:
axs[imu].plot(gyro[imu]['time'], gyro[imu][axis]*scale, label='Uncorrected %s' % axis) axs[imu].plot(data.gyro[imu]['time'], data.gyro[imu][axis]*scale, label='Uncorrected %s' % axis)
for axis in axes: for axis in AXES:
poly = np.poly1d(gcoef[imu][axis]) poly = np.poly1d(c.gcoef[imu][axis])
correction = poly(trel[imu]) trel = data.gyro[imu]['T'] - tref
axs[imu].plot(gyro[imu]['time'], (gyro[imu][axis] - correction)*scale, label='Corrected %s' % axis) correction = poly(trel)
axs[imu].plot(data.gyro[imu]['time'], (data.gyro[imu][axis] - correction)*scale, label='Corrected %s' % axis)
if args.log_parm:
for axis in AXES:
if clog.enable[imu] == 0.0:
print("IMU[%u] disabled in log parms" % imu)
continue
poly = np.poly1d(clog.gcoef[imu][axis])
tmid = 0.5*(clog.tmin[imu]+clog.tmax[imu])
correction = poly(data.gyro[imu]['T'] - tmid)
axs[imu].plot(data.gyro[imu]['time'], (data.gyro[imu][axis] - correction)*scale, label='Corrected %s (log parm)' % axis)
ax2 = axs[imu].twinx() ax2 = axs[imu].twinx()
ax2.plot(gyro[imu]['time'], gyro[imu]['T'], label='Temperature(C)', color='black') ax2.plot(data.gyro[imu]['time'], data.gyro[imu]['T'], label='Temperature(C)', color='black')
ax2.legend(loc='upper right') ax2.legend(loc='upper right')
axs[imu].legend(loc='upper left') axs[imu].legend(loc='upper left')
axs[imu].set_title('IMU[%u] Gyro (deg/s)' % imu) axs[imu].set_title('IMU[%u] Gyro (deg/s)' % imu)
fig, axs = pyplot.subplots(len(accel), 1, sharex=True) fig, axs = pyplot.subplots(num_imus, 1, sharex=True)
if len(accel) == 1: if num_imus == 1:
axs = [axs] axs = [axs]
for imu in accel: for imu in data.IMUs():
mean = {} mean = {}
for axis in axes: for axis in AXES:
mean[axis] = np.mean(accel[imu][axis]) mean[axis] = np.mean(data.accel[imu][axis])
axs[imu].plot(accel[imu]['time'], accel[imu][axis] - mean[axis], label='Uncorrected %s' % axis) axs[imu].plot(data.accel[imu]['time'], data.accel[imu][axis] - mean[axis], label='Uncorrected %s' % axis)
for axis in axes: for axis in AXES:
poly = np.poly1d(acoef[imu][axis]) poly = np.poly1d(c.acoef[imu][axis])
correction = poly(trel[imu]) trel = data.accel[imu]['T'] - tref
axs[imu].plot(accel[imu]['time'], (accel[imu][axis]-mean[axis]) - correction, label='Corrected %s' % axis) correction = poly(trel)
axs[imu].plot(data.accel[imu]['time'], (data.accel[imu][axis]-mean[axis]) - correction, label='Corrected %s' % axis)
if args.log_parm:
for axis in AXES:
if clog.enable[imu] == 0.0:
print("IMU[%u] disabled in log parms" % imu)
continue
poly = np.poly1d(clog.acoef[imu][axis])
tmid = 0.5*(clog.tmin[imu]+clog.tmax[imu])
correction = poly(data.accel[imu]['T'] - tmid)
axs[imu].plot(data.accel[imu]['time'], (data.accel[imu][axis]-mean[axis]) - correction, label='Corrected %s (log parm)' % axis)
ax2 = axs[imu].twinx() ax2 = axs[imu].twinx()
ax2.plot(accel[imu]['time'], accel[imu]['T'], label='Temperature(C)', color='black') ax2.plot(data.accel[imu]['time'], data.accel[imu]['T'], label='Temperature(C)', color='black')
ax2.legend(loc='upper right') ax2.legend(loc='upper right')
axs[imu].legend(loc='upper left') axs[imu].legend(loc='upper left')
axs[imu].set_title('IMU[%u] Accel (m/s^2)' % imu) axs[imu].set_title('IMU[%u] Accel (m/s^2)' % imu)