Here are three pictures of PR2Lite at Maker Faire 2013 that Melonee Wise took! This was when we had PR2Lite attempt to play chess with Michael Ferguson’s Maxwell.
Our second article for “SERVO” magazine is on page 34 of the August 2013 issue, and is called “PR2Lite Grows Up — and So Do Its Makers” by Alan Downing, Matthew Downing (me), and Frank Ou.
We submitted an article on PR2Lite to Servo.
We fixed bugs discovered during recent testing on the torso controller, the head controller, and the base controller.
We have reliability problems when using both the base (wheels and linear actuator) and the upper arms. This appears to be due to the length of the cable and packet collisions. If we run just the upper arms or just the base, things appear to work pretty well.
On May 18 & 19, 2013, we brought PR2Lite to the Bay Area Maker Faire in the San Mateo County Event Center. With Maxwell, by Michael Ferguson, we had a booth of the two robots playing chess autonomously against each other. Maxwell possessed the dexterity required for moving the individual pieces. PR2Lite on the other hand had trouble, especially because the servos would overheat due to holding up the arms for too long (the robot took time while planning its arm movements). Overall, it was a successful Maker Faire trip, and we had a well placed booth, so many people stopped by to learn about our work.
We also had to create a new way of transporting the robot, because last year we had a piece break off because of jostling during transportation. It was built in one day, and could be strapped down onto the floor of the car. This year it worked perfectly. Here’s what it looked like:
PR2Lite and Maxwell didn’t get to play chess at Robogames, but we’re still planning to have PR2Lite take on Maxwell at Maker Faire on the weekend of May 18. Unfortunately, despite a steady stream of progress, PR2Lite still isn’t picking up and moving pieces autonomously yet. Some of the progress made includes:
- The ROS arm navigation GUI works with PR2Lite again. This required many tiny fixes that had accumulated since the beginning of the year when the GUI stopped working – apparently due to a package name change that resulted in unexpected dynamic linking of the wrong plug-in.
- Adapting the turtleblot “block manipulation” GUI for PR2Lite chess playing
- Integrating in the “pr2_arms.py” utility routines from the assistive teleop project.
- Adjusting the URDF to be more accurate.
- Fixing minor bugs in various controllers.
- Fixed a broken connector
- Due to work obligations, Frank’s work on the revised PR2lite SLAM navigation is on hold until after Maker Faire. Currently, working on some odometry problems.
Due to RoboFest, RoboGames, and a heavy end-of-school-year load, Matthew’s revised gripper controller probably won’t be ready to show off the velo gripper and heavy-duty arm actuators at Maker Faire. AutoCAD design continues.
The paper is on the topics of low-cost robots, ROS utilization, and 3-D mapping.
PR2-Lite is mentioned in the penultimate section. Maxwell is Michael Feruson’s robot, and will be joining us at Maker Faire Bay Area 2013 playing chess with PR2 Lite.