getOdometry

Get odometry reading from TurtleBot

Description

example

odom = getOdometry(tbot) waits for the next published odometry message from the TurtleBot® connected through the interface object, tbot,and returns the odometry. If no message is received in five seconds, the function displays an error.

[odom,odomMsg] = getOdometry(tbot) also returns the received ROS odometry message.

[___] = getOdometry(tbot,timeout) waits for the next image for timeout seconds. If no new message is received in that time, the function displays an error. A timeout of zero returns the latest received message without waiting. If no message has been received, the function returns an empty matrix for odom and an empty message for odomMsg, if specified.

Examples

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Connect to the TurtleBot robot. Change '192.168.1.1' to the IP address of the robot.

tbot = turtlebot('192.168.1.1');

Get the latest odometry reading from the TurtleBot.

odom = getOdometry(tbot);

Input Arguments

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TurtleBot interface object, specified as a turtlebot object. The object contains properties for activating subscribers and accessing topic names relevant to the TurtleBot. The properties contain the topic name and active status of different subscribers for the TurtleBot. When you create the object with turtlebot, the properties available are:

tbot = turtlebot
tbot = 

  turtlebot with properties:

           Velocity: [1x1 struct]
         ColorImage: [1x1 struct]
          GrayImage: [1x1 struct]
         DepthImage: [1x1 struct]
         PointCloud: [1x1 struct]
          LaserScan: [1x1 struct]
           Odometry: [1x1 struct]
      OdometryReset: [1x1 struct]
                IMU: [1x1 struct]
    TransformFrames: {0x1 cell}
         TopicNames: {3x1 cell}

For properties with relevant ROS data messages , you can view the topic name and a subscriber’s active status. A specific subscriber is active for the given TopicName if Active equals 1.

tbot.Velocity
ans = 

    TopicName: '/mobile_base/commands/velocity'
       Active: 1

Timeout for receiving an image, specified as a scalar in seconds. The function returns an error after timeout seconds. If timeout equals zero, the function returns the latest image. If the TurtleBot has no latest message, the function returns a blank image and blank image message.

Output Arguments

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Odometry reading, returned as a structure containing these fields:

  • Position – A three-element row vector containing the 3-D position estimate of the TurtleBot odometry as [x y z] in meters.

  • Orientation – A three-element row vector containing the 3-D orientation estimate of the TurtleBot based on the odometry reading. The orientation is returned in [raw pitch roll] form with angles is radians.

'nav_msgs/Odometry' ROS odometry message, returned as an Odometry object handle.

Introduced in R2016a