A ROS project developed as part of ME495 - Embedded Systems in Robotics course at Northwestern University (NU).
To launch (in a ROS workspace), type in terminal:
cd ~/baxter_ws/
. baxter.sh
rosrun baxter_tools enable_robot.py -e
roslaunch baxter_two baxter_two.launch
Use baxter to pick and place objects from one location to another
The following sections describe contents of this package and how to use them:
The following packages need to be installed for baxter_two
package to work:
- Baxter SDK - to be installed in
baxter_ws/src
directory - MoveIt!
- moveit_python by Michael Ferguson - to be installed in
baxter_ws/src
directory - Baxter Simulator - v1.1 (ONLY needed if NOT working with actual baxter robot)
The baxter_two
package consists of following main files:
-
baxter_two.launch: A launch file that starts the following nodes:
- joint_action_trajectory_server.py (required for MoveIt!)
- MoveIt! with rviz
- baxter_img.cpp
- baxter_pnp.py
-
baxter_img.cpp: subscribes to the
/cameras/right_hand_camera/image
topic, calculates object locations using OpenCV tools, and publishes this information tobaxter_pnp
node via aPoseArray()
message -
baxter_pnp.py: subscribes to the topic (called
Dpos
) published by baxter_img, and callsPlanningSceneInterface
andMoveGroupInterface
classes frommoveit_python
bindings to add collision objects and move baxter's arms respectively- Allows both arms to be moved at the same time
- Allows velocity scaling using
max_velocity_scaling_factor
- Uses
baxter_interface
for gripper control
This section gives a step-by-step approach to run a successful baxter pick and place with this package.
- Items needed - a table of height ~ 0.6 m; square blocks (with green top surface); a baxter robot with electric parallel grippers; an ethernet cable (to connect baxter to computer)
- Set up networking with baxter
- Install the required packages as outlined in Prerequisites section
- Clone this package to your
baxter_ws/src
directory - Source
baxter.sh
file, enable the robot, and launchbaxter_two.launch
as follows
cd ~/baxter_ws/
. baxter.sh
rosrun baxter_tools enable_robot.py -e
roslaunch baxter_two baxter_two.launch
The following rqt_graph shows a ROS computation graph for baxter pick and place highlighting all important nodes and topics during operation:
-
Camera Calibration: We are looking into improving the camera calibration. Currently, variations in surrounding lighting affect the object detection. Using more finely-tuned methods of calibrating the camera will minimize the lighting issue.
-
GUI Development: We are also looking to create a Graphical User Interface (GUI) that allows the user to click an object in the virtual world (e.g in Gazebo), and pick and place that particular object. This GUI is currently under development.