diff options
Diffstat (limited to 'mavlink/share/pyshared/pymavlink/examples/magfit_delta.py')
-rw-r--r-- | mavlink/share/pyshared/pymavlink/examples/magfit_delta.py | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/mavlink/share/pyshared/pymavlink/examples/magfit_delta.py b/mavlink/share/pyshared/pymavlink/examples/magfit_delta.py deleted file mode 100644 index 87d2dbb7f..000000000 --- a/mavlink/share/pyshared/pymavlink/examples/magfit_delta.py +++ /dev/null @@ -1,145 +0,0 @@ -#!/usr/bin/env python - -''' -fit best estimate of magnetometer offsets using the algorithm from -Bill Premerlani -''' - -import sys, time, os, math - -# allow import from the parent directory, where mavlink.py is -sys.path.insert(0, os.path.join(os.path.dirname(os.path.realpath(__file__)), '..')) - -# command line option handling -from optparse import OptionParser -parser = OptionParser("magfit_delta.py [options]") -parser.add_option("--no-timestamps",dest="notimestamps", action='store_true', help="Log doesn't have timestamps") -parser.add_option("--condition",dest="condition", default=None, help="select packets by condition") -parser.add_option("--mav10", action='store_true', default=False, help="Use MAVLink protocol 1.0") -parser.add_option("--verbose", action='store_true', default=False, help="verbose offset output") -parser.add_option("--gain", type='float', default=0.01, help="algorithm gain") -parser.add_option("--noise", type='float', default=0, help="noise to add") -parser.add_option("--max-change", type='float', default=10, help="max step change") -parser.add_option("--min-diff", type='float', default=50, help="min mag vector delta") -parser.add_option("--history", type='int', default=20, help="how many points to keep") -parser.add_option("--repeat", type='int', default=1, help="number of repeats through the data") - -(opts, args) = parser.parse_args() - -if opts.mav10: - os.environ['MAVLINK10'] = '1' -import mavutil -from rotmat import Vector3, Matrix3 - -if len(args) < 1: - print("Usage: magfit_delta.py [options] <LOGFILE...>") - sys.exit(1) - -def noise(): - '''a noise vector''' - from random import gauss - v = Vector3(gauss(0, 1), gauss(0, 1), gauss(0, 1)) - v.normalize() - return v * opts.noise - -def find_offsets(data, ofs): - '''find mag offsets by applying Bills "offsets revisited" algorithm - on the data - - This is an implementation of the algorithm from: - http://gentlenav.googlecode.com/files/MagnetometerOffsetNullingRevisited.pdf - ''' - - # a limit on the maximum change in each step - max_change = opts.max_change - - # the gain factor for the algorithm - gain = opts.gain - - data2 = [] - for d in data: - d = d.copy() + noise() - d.x = float(int(d.x + 0.5)) - d.y = float(int(d.y + 0.5)) - d.z = float(int(d.z + 0.5)) - data2.append(d) - data = data2 - - history_idx = 0 - mag_history = data[0:opts.history] - - for i in range(opts.history, len(data)): - B1 = mag_history[history_idx] + ofs - B2 = data[i] + ofs - - diff = B2 - B1 - diff_length = diff.length() - if diff_length <= opts.min_diff: - # the mag vector hasn't changed enough - we don't get any - # information from this - history_idx = (history_idx+1) % opts.history - continue - - mag_history[history_idx] = data[i] - history_idx = (history_idx+1) % opts.history - - # equation 6 of Bills paper - delta = diff * (gain * (B2.length() - B1.length()) / diff_length) - - # limit the change from any one reading. This is to prevent - # single crazy readings from throwing off the offsets for a long - # time - delta_length = delta.length() - if max_change != 0 and delta_length > max_change: - delta *= max_change / delta_length - - # set the new offsets - ofs = ofs - delta - - if opts.verbose: - print ofs - return ofs - - -def magfit(logfile): - '''find best magnetometer offset fit to a log file''' - - print("Processing log %s" % filename) - - # open the log file - mlog = mavutil.mavlink_connection(filename, notimestamps=opts.notimestamps) - - data = [] - mag = None - offsets = Vector3(0,0,0) - - # now gather all the data - while True: - # get the next MAVLink message in the log - m = mlog.recv_match(condition=opts.condition) - if m is None: - break - if m.get_type() == "SENSOR_OFFSETS": - # update offsets that were used during this flight - offsets = Vector3(m.mag_ofs_x, m.mag_ofs_y, m.mag_ofs_z) - if m.get_type() == "RAW_IMU" and offsets != None: - # extract one mag vector, removing the offsets that were - # used during that flight to get the raw sensor values - mag = Vector3(m.xmag, m.ymag, m.zmag) - offsets - data.append(mag) - - print("Extracted %u data points" % len(data)) - print("Current offsets: %s" % offsets) - - # run the fitting algorithm - ofs = offsets - ofs = Vector3(0,0,0) - for r in range(opts.repeat): - ofs = find_offsets(data, ofs) - print('Loop %u offsets %s' % (r, ofs)) - sys.stdout.flush() - print("New offsets: %s" % ofs) - -total = 0.0 -for filename in args: - magfit(filename) |