Inheritance diagram for ros_ips.positioning_plus.PositioningPlus:

Public Member Functions
def	__init__ (self, config_dir, min_beacons=4, max_z=None)

def	get_range (self, responses)

def	get_top_beacons (self, pings, n)

def	in_range (self, pings)

def	parse_srg (self, responses)

def	trilaterate (self, ranges)

Static Public Member Functions
def	mse (x, points, distances)

Public Attributes
	eids

	max_z

	min_beacons

Static Public Attributes
	minimization_params

Detailed Description

Class to extend the functionality of the Positioning class with UWB ranging capabilities.

Definition at line 20 of file src/ros_ips/positioning_plus.py.

Constructor & Destructor Documentation

def ros_ips.positioning_plus.PositioningPlus.__init__	(	self,
		config_dir,
		min_beacons = `4`,
		max_z = `None`
	)

Initialize the class with zone and beacon definitions from YAML configuration file.
:param config_dir: String: Directory of the YAML config file
:param min_beacons: Int: Minimum number of beacons to use for trilateration
:param max_z: Float: Maximum z position the receiver can have after ranging

Definition at line 27 of file src/ros_ips/positioning_plus.py.

Member Function Documentation

def ros_ips.positioning_plus.PositioningPlus.get_range	(	self,
		responses
	)

Definition at line 70 of file src/ros_ips/positioning_plus.py.

def ros_ips.positioning_plus.PositioningPlus.get_top_beacons	(	self,
		pings,
		n
	)

Get the top n beacons in terms of RSSI values from a list of beacon pings.
:param pings: [String]: list of beacon pings
:param n: Int: Number of top beacons to return
:return: [Beacon]: list of beacon objects ordered according to RSSI values

Definition at line 46 of file src/ros_ips/positioning_plus.py.

def ros_ips.positioning_plus.PositioningPlus.in_range	(	self,
		pings
	)

Get a list of beacons that are in range and are configured in the configuration YAML file from a list of
beacon pings recorded over a short duration. The returned beacons (EIDs can be used for UWB ranging)
:param pings: [String]: List of BCN pings
:return: [String]: List of EIDs that can be used for ranging

Definition at line 98 of file src/ros_ips/positioning_plus.py.

def ros_ips.positioning_plus.PositioningPlus.mse	(	x,
		points,
		distances
	)

static

Cost-function to use for position estimation. Minimize the squared error of the distance between a variable
point x and each beacon and the measured UWB distance. mse = SUM(distance - dist(x, points)^2
:param x: [Float, Float, Float]: vector with variable components to be optimized
:param points: [[x, y, z], ...]: list of positions of the beacons used for UWB ranging
:param distances: [Float]: estimated distances from UWB ranging of above beacons
:return: Float: mean squared error for all beacon positions

Definition at line 151 of file src/ros_ips/positioning_plus.py.

def ros_ips.positioning_plus.PositioningPlus.parse_srg	(	self,
		responses
	)

Parse a list of SRG ranging responses of UWB beacons. For each message (if it is valid) return the positions,
frame id and estimated ranges.
:param responses: [String]: list of SRG responses from UWB beacons
:return: [(Beacon, Float)]: list beacon-object and range pairs

Definition at line 74 of file src/ros_ips/positioning_plus.py.

def ros_ips.positioning_plus.PositioningPlus.trilaterate	(	self,
		ranges
	)

Estimate the position of the receiver by using trilateration with at least three UWB responses
:param ranges: [([Float, Float, Float], Float)]: list of position and range pairs (obtained from parse_srg) or
       [(Beacon, Float)]: list of beacon object and range pairs (output from parse_srg())
:return: [Float, Float, Float]: 3D coordinates of estimated receiver location

Definition at line 114 of file src/ros_ips/positioning_plus.py.