LaserScanner

class mobrob_behcon.connectors.laserscanner.LaserScanner(ros_topic, visu)

The class LaserScanner

Represents a connector to the laserscanner topics of the robot. Provides a function to get the latest laserscan from the laserscanner on the robot.

Methods

__init__(ros_topic, visu)	constructor
calc_dist(x, y)	Calculate distance from origin to given point
callback(msg)	callback function for topics of type sensor_msgs/LaserScan
check_box(x1, y1, x2, y2)	Check if some obstacle is in given box.
draw_laserpoints()	Draw all laser scanpoints to visualisation
extract_points(ranges)	Extract points from a list of distances
filter_points(list, x_min, x_max, y_min, y_max)	Filter given list of points (x, y) with the given bounderies
get_current_time()	Get current time in milliseconds
get_lst_scan_points()	Get current laserscan as a list of points
get_x(radius, angle)	Get x-coordinate of given point in polar coordinates
get_y(radius, angle)	Get y-coordinate of given point in polar coordinates

Details

__init__(ros_topic, visu)

constructor

Parameters

ros_topic (string) – topic of the LaserScan data

static calc_dist(x, y)

Calculate distance from origin to given point

Parameters

• x (float) – x-coordinate [m]

• y (float) – y-coordinate [m]

Returns

distance [m]

Return type

float

callback(msg)

callback function for topics of type sensor_msgs/LaserScan

Parameters

msg – receiving message

check_box(x1, y1, x2, y2)

Check if some obstacle is in given box. Returns distance.

Parameters

• x1 (float) – x-coordinate of first corner of box

• y1 (float) – y-coordinate of first corner of box

• x2 (float) – x-coordinate of second corner of box

• y2 (float) – y-coordinate of second corner of box

Returns

distance to nearest point in this box, if no obstacle in box returns 0

Return type

float

draw_laserpoints()

Draw all laser scanpoints to visualisation

static extract_points(ranges)

Extract points from a list of distances

Parameters

ranges (list(float)) – list of distances (length=360)

Returns

list of points (x, y)

Return type

list((float, float))

static filter_points(list, x_min, x_max, y_min, y_max)

Filter given list of points (x, y) with the given bounderies

Parameters

• list (list((float, float))) – list of points (x, y)

• x_min (float) – lower bound x

• x_max (float) – upper bound x

• y_min (float) – lower bound y

• y_max (float) – upper bound y

Returns

filtered list of points (x, y)

Return type

list((float, float))

static get_current_time()

Get current time in milliseconds

Returns

time in milliseconds

get_lst_scan_points()

Get current laserscan as a list of points

Returns

laserscan as a list of points (x,y)

Return type

list((float, float))

static get_x(radius, angle)

Get x-coordinate of given point in polar coordinates

Parameters

• radius (float) – radius [m]

• angle (float) – angle [deg]

Returns

x-coordinate [m]

Return type

float

static get_y(radius, angle)

Get y-coordinate of given point in polar coordinates

Parameters

• radius (float) – radius [m]

• angle (float) – angle [deg]

Returns

y-coordinate [m]

Return type

float