Only released in EOL distros:  

nxt: nxt_controllers | nxt_description | nxt_lxf2urdf | nxt_msgs | nxt_python | nxt_ros | nxt_rviz_plugin

Package LinksDependencies (7)
Used by (2)

Package Summary

No API documentation

The nxt_controllers package provides a number of Python-based controllers for two-wheeled diff drive robots. The base controllers allows you to send velocity commands to a diff drive base, while the base odometry tracks the pose of a diff drive robot. The nxt_controllers package also contains a general purpose joint position controller that commnads a joint to a desired position by sending effort commands to the joint and reading the joint encoders.

nxt: nxt_controllers | nxt_description | nxt_lxf2urdf | nxt_msgs | nxt_python | nxt_ros | nxt_rviz_plugin
Package LinksDependencies (7)
Used by (2)

Package Summary

Documented

The nxt_controllers package provides a number of Python-based controllers for two-wheeled diff drive robots. The base controllers allows you to send velocity commands to a diff drive base, while the base odometry tracks the pose of a diff drive robot. The nxt_controllers package also contains a general purpose joint position controller that commnads a joint to a desired position by sending effort commands to the joint and reading the joint encoders.

Contents

  1. ROS API description
    1. nxt_base_controller
      1. Subscribed Topics
      2. Published Topics
      3. Parameters
    2. nxt_base_odometry
      1. Subscribed Topics
      2. Published Topics
      3. Parameters

ROS API description

nxt_base_controller

nxt_base_controller provides a controller for a basic differential drive vehicle (i.e. a car).

Subscribed Topics

~joint_states (sensor_msgs/JointState)
  • The current effort, position, and velocity of the servo motors.
~cmd_vel (geometry/Twist)
  • The desired linear and angular x,y,z of the base.

Published Topics

~joint_command (nxt_msgs/JointCommand)
  • Effort commands to move the motors.

Parameters

~base_parameters/r_wheel_joint (string, default: None)
  • The name of the right wheel joint.
~base_parameters/l_wheel_joint (string, default: None)
  • The name of the left wheel joint.
~base_parameters/wheel_radius (double, default: 0.022)
  • The radius of the Lego wheel, this assumes both wheels have the same radius.
~base_parameters/wheel_basis (double, default: 0.055)
  • The distance from the center of each wheel divided by 2.
~base_parameters/vel_to_eff (double, default: 0.55)
  • The ratio of the output velocity to the commanded effort.

nxt_base_odometry

nxt_base_odometry provides odometry for a basic differential drive vehicle (i.e. a car).

Subscribed Topics

~joint_states (sensor_msgs/JointState)
  • The current effort, position, and velocity of the servo motors.

Published Topics

~odom (nav_msgs/Odometry)
  • The change in position over time in the fixed frame.

Parameters

~base_parameters/r_wheel_joint (string, default: None)
  • The name of the right wheel joint.
~base_parameters/l_wheel_joint (string, default: None)
  • The name of the left wheel joint.
~base_parameters/wheel_radius (double, default: 0.022)
  • The radius of the Lego wheel, this assumes both wheels have the same radius.
~base_parameters/wheel_basis (double, default: 0.055)
  • The distance from the center of each wheel divided by 2.

Wiki: nxt_controllers (last edited 2010-08-19 17:05:08 by wim)

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