|Transform message entities into target frame|
|Verify if transformation is available|
|Transform message entities into target coordinate frame|
|Wait until a transformation is available|
|Retrieve transformation between two coordinate frames|
|Send transformation to ROS network|
Summary of the structure of rosbags and the workflow for selecting subsets of messages in a rosbag.
A rosbag or bag is a file format in ROS for storing message data. These bags are often created by subscribing to one or more ROS topics, and storing the received message data in an efficient file structure. MATLAB® can read these rosbag files and help with filtering and extracting message data. See ROS Log Files (rosbags) for more information about rosbag support in MATLAB.
The tf system in ROS keeps track of multiple coordinate frames and maintains the relationship between them in a tree structure. tf is distributed, so that all coordinate frame information is available to every node in the ROS network. MATLAB® enables you to access this transformation tree. This example familiarizes you with accessing the available coordinate frames, retrieving transformations between them, and transform points, vectors, and other entities between any two coordinate frames.
rosrate object allows you to control the rate of your
code execution based on the ROS Time
This example shows how to time stamp a ROS message with the current system time of your computer. Use the Current Time block and assign the output to the
std_msgs/Header message in the Stamp field. Publish the message on a desired topic.
This model subscribes to a
Pose message on the ROS network and converts it to a homogeneous transmation. Use bus selectors to extract the rotation and translation vectors. The Coordinate Transformation Conversion block takes the rotation vector (euler angles) and translation vector in and gives the homogeneous transformation for the message.