scaled_fjt_controller

A ros2 basic implementation of the scaled_fjt_controller in scaled_follow_joint_trajectory_controller.

This package implements a ros2_controller as a FollowJointTrajectory Action with the possibility to dynamically scale the execution velocity in runtime.

This controller inherits directly from the joint_trajectory_controller/JointTrajectoryController.

Installation

If you are already using ros2_control with the ros2_controllers, no additional modules are required. Just

cd <to/your/ros2_ws>/src
git clone https://github.com/paolofrance/scaled_fjt_controller
cd ..
colcon build --symlink-install

source your workspace.

Usage

In your ros2_controllers configuration file, set the following

controller_manager:
  ros__parameters:

    manipulator_controller:
      type: "scaled_fjt_controller/ScaledFjtController"

manipulator_controller:
  ros__parameters:
    joints:
      - J1
      - J2
      - J3
      - J4
      - J5
      - J6
    command_interfaces:
      - position
    state_interfaces:
      - position
      - velocity
    open_loop_control: true
    constraints:
      goal_time: 0.0

Now you can bring up your robot packages and load this controller.

To scale the velocity, on a new terminal, simply type

ros2 topic pub /speed_ovr std_msgs/msg/Int16 {"data: 10"}

The {"data: 10"} value can take any integer in the range [0-100] and represents a percentage of the nominal velocity of the goal trajectory.

An example of usage with Moveit! is available here.

TODO:

1. At the current state, it only implements positions as command_interfaces. It would be nice to also allow other command_interfaces.