Teleop Twist Keyboard Node

Subscribes to:

/scan

Publishes to:

/cmd_vel

it can implement two behaviours on robot:

1: moving without obstacle avoidance:
user can move the robot using keys it publishes the desired movements to cmd_vel topic

2: moveing with obstacle avoidance:
subscribes scan topic and uses it to detect obstacles. user can move the robot using keys and it also avoids the robot from colliding the obstacles

Here is the instruction for controlling the robot with keyboard:

Moving around

u

i

o

j

k

l

m

,

.

Holonomic mode(strafing)

U

I

O

J

K

L

M

<

>

t : up (+z)

b : down (-z)

anything else : stop

q/z : increase/decrease max speeds by 10%

w/x : increase/decrease only linear speed by 10%

e/c : increase/decrease only angular speed by 10%

CTRL-C to change robot behaviour

class scripts.teleop_twist_keyboard.PublishThread(rate)[source]

A class which is used for synchronization and publishing robot’s twist into cmd_vel topic

Attributes:

x, y, z, th, speed, turnfloat: Robot’s Position Information
donebool: Robot State

Methods:

run()[source]: Detects if user has chosen the obstacle avoidance option and moves the robot by publishing the twist to cmd_vel topic

stop()[source]: Stops the robot

update(x, y, z, th, speed, turn)[source]: Updates robots position information

wait_for_subscribers()[source]: Waits for subscribers to connect to the topic

scripts.teleop_twist_keyboard.clbk_laser(msg)[source]

Callback function for subscring laser scan topic

Parameters: msg (float) – rangefinder sensor data

scripts.teleop_twist_keyboard.getKey(key_timeout)[source]

Gets commands from user

Parameters: key_timeout (float) – timeout for input key
Returns: user input key
Return type: key(str)

scripts.teleop_twist_keyboard.teleop()[source]: Provides the interface and publishes user command to cmd_vel topic

scripts.teleop_twist_keyboard.vels(speed, turn)[source]

Puts the current speed of robot in a message string

Parameters

speed (float) – robot’s linear speed
turn (float) – robot’s angular speed

Returns

a message string that shows robot’s twist

Return type

msg(str)