# vector3d.py 3D vector class for use in inertial measurement unit drivers # Authors Peter Hinch, Sebastian Plamauer # V0.7 17th May 2017 pyb replaced with utime # V0.6 18th June 2015 ''' The MIT License (MIT) Copyright (c) 2014 Sebastian Plamauer, oeplse@gmail.com, Peter Hinch Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ''' from utime import sleep_ms from math import sqrt, degrees, acos, atan2 def default_wait(): ''' delay of 50 ms ''' sleep_ms(50) class Vector3d(object): ''' Represents a vector in a 3D space using Cartesian coordinates. Internally uses sensor relative coordinates. Returns vehicle-relative x, y and z values. ''' def __init__(self, transposition, scaling, update_function): self._vector = [0, 0, 0] self._ivector = [0, 0, 0] self.cal = (0, 0, 0) self.argcheck(transposition, "Transposition") self.argcheck(scaling, "Scaling") if set(transposition) != {0, 1, 2}: raise ValueError('Transpose indices must be unique and in range 0-2') self._scale = scaling self._transpose = transposition self.update = update_function def argcheck(self, arg, name): ''' checks if arguments are of correct length ''' if len(arg) != 3 or not (type(arg) is list or type(arg) is tuple): raise ValueError(name + ' must be a 3 element list or tuple') def calibrate(self, stopfunc, waitfunc=default_wait): ''' calibration routine, sets cal ''' self.update() maxvec = self._vector[:] # Initialise max and min lists with current values minvec = self._vector[:] while not stopfunc(): waitfunc() self.update() maxvec = list(map(max, maxvec, self._vector)) minvec = list(map(min, minvec, self._vector)) self.cal = tuple(map(lambda a, b: (a + b)/2, maxvec, minvec)) @property def _calvector(self): ''' Vector adjusted for calibration offsets ''' return list(map(lambda val, offset: val - offset, self._vector, self.cal)) @property def x(self): # Corrected, vehicle relative floating point values self.update() return self._calvector[self._transpose[0]] * self._scale[0] @property def y(self): self.update() return self._calvector[self._transpose[1]] * self._scale[1] @property def z(self): self.update() return self._calvector[self._transpose[2]] * self._scale[2] @property def xyz(self): self.update() return (self._calvector[self._transpose[0]] * self._scale[0], self._calvector[self._transpose[1]] * self._scale[1], self._calvector[self._transpose[2]] * self._scale[2]) @property def magnitude(self): x, y, z = self.xyz # All measurements must correspond to the same instant return sqrt(x**2 + y**2 + z**2) @property def inclination(self): x, y, z = self.xyz return degrees(acos(z / sqrt(x**2 + y**2 + z**2))) @property def elevation(self): return 90 - self.inclination @property def azimuth(self): x, y, z = self.xyz return degrees(atan2(y, x)) # Raw uncorrected integer values from sensor @property def ix(self): return self._ivector[0] @property def iy(self): return self._ivector[1] @property def iz(self): return self._ivector[2] @property def ixyz(self): return self._ivector @property def transpose(self): return tuple(self._transpose) @property def scale(self): return tuple(self._scale)