How does ROS navigation work?

The ROS Navigation Stack is meant for 2D maps, square or circular robots with a holonomic drive, and a planar laser scanner, all of which a Turtlebot has. It uses odometry, sensor data, and a goal pose to give safe velocity commands. The node “move_base” is where all the magic happens in the ROS Navigation Stack.

What is the package used for ROS navigation?

AMCL Configuration The ROS Navigation Stack requires the use of AMCL (Adaptive Monte Carlo Localization), a probabilistic localization system for a robot. AMCL is used to track the pose of a robot against a known map.

What is Move_base in ROS?

The move_base package provides an implementation of an action (see the actionlib package) that, given a goal in the world, will attempt to reach it with a mobile base. The move_base node links together a global and local planner to accomplish its global navigation task.

What is the navigation stack?

The flexible navigation stack is a set of components that realize specific navigation services to provide a flexibly applicable navigation capability for a service robot.

What is localization in ROS?

Localizing a Robot Suppressed/replicated based on how well the laser scan fits the map, given the position of the particle. ▪ The localization is integrated in ROS by emitting a transform from a map-frame to the odom frame that “corrects” the odometry.

How is RRT implemented in ROS?

Source the setup file of the rrt-ros to make the rrt-planning package visible to ros. Run roscore in another terminal. Then run rrt node as follows. You will be now promped to run rviz for visualization.

What is Gmapping in ROS?

The gmapping package provides laser-based SLAM (Simultaneous Localization and Mapping), as a ROS node called slam_gmapping. Using slam_gmapping, you can create a 2-D occupancy grid map (like a building floorplan) from laser and pose data collected by a mobile robot.

What is Costmap?

A costmap is a grid map where each cell is assigned a specific value or cost: higher costs indicate a smaller distance between the robot and an obstacle. Path-finding is done by a planner which uses a series of different algorithms to find the shortest path while avoiding obstacles.

What is Cmd_vel in Ros?

cmd_vel – The main user interface topic (priority: 90). nav_vel – This topic is used is used by the move_base to send navigation commands (priority: 80). The output topic is mobile_base_controller/cmd_vel, it’s not recommended to publish Twist messages directly to this topic.

What is Localisation in ROS?

The localization is integrated in ROS by emitting a transform from a map-frame to the odom frame that “corrects” the odometry. ▪ To query the robot position according to the localization you should ask the transform of base_footprint in the map frame.

What is Hector mapping?

hector_mapping is a SLAM approach that can be used without odometry as well as on platforms that exhibit roll/pitch motion (of the sensor, the platform or both).

What is a robot position?

Joint Space (or Joint Coordinates) is just a method of defining the position of the robot in terms of the value of each axis instead of as a TCP position. For example, the Home Position of a robot is often defined in Joint Space as each axis being at 0 degrees.