Maxwell (Finally) Gets a Vertical Arm Lift

I've been saying for quite some time that I wanted to add a vertical lift to Maxwell. Earlier this month, he finally got that lift:


The linear actuator gives the arm 20" of additional vertical mobility, making it possible to grab objects at floor or table height, or hit most light switches. The lift is currently integrated into ROS arm_navigation, I'll have some awesome videos soon.

In addition to the arm upgrades, Maxwell recently got a new ASUS Xtion Pro Live to replace his Kinect. The ASUS device requires only USB (no 12V power) and is significantly less heavy, reducing neck and back stress (a common problem amongst aging robots). Speaking of aging robots, Maxwell turns one early next month.

-Fergs

Update Palooza

This blog went a bit quieter earlier this year. That is about to change.

First up, is a series of awesome pictures of a new 3d-printed gripper for Maxwell. One of the cool tools that I have access to these days is a Project HD3000 printer. Here's the grippers straight off the printer:
After removing the wax:
One side installed:
And a grasp:

Maxwell vs Shallow Blue Video

Maxwell Wins at AAAI

Maxwell won 1st place in the 2011 AAAI Small Scale Manipulation Challenge! Video and photos soon video soon.

-Fergs

ROSSerial Released

My first project of the summer here at Willow is now in release: rosserial. (It was actually released about 2 weeks ago).

This is a new library for connecting the Arduino platform to ROS, allowing an Arduino to directly publish and subscribe to ROS messages. There are also demos ranging from controlling servos to using an Arduino and rxplot as an oscilloscope to reading temperature sensors into ROS.

In addition to support integration with the Arduino platform, the rosserial library provides a general point-to-point transport for ROS communication over serial, which is intended for hardware that cannot support the full ROS TCP/IP network stack. This library can be used to easily integrate a wide-variety of low-cost hardware into ROS.

Debian packages are now available for diamondback and unstable (shortly electric).

See more at: http://www.ros.org/wiki/rosserial

-Fergs

A New Gripper for Mini Max

I was never satisfied with the simple gripper we had put on the Mini Maxwell prototypes. It took a bit of time to actually sit down and create the gripper I wanted, but I've now printed up a couple prototypes (the final versions will be laser cut):
The design was done in Autodesk Inventor:
There is a simple mechanism for converting the motion of a single AX-12 to parallel motion for both jaws:Videos shortly of Mini Max manipulating things.

-Fergs

Introducing Mini Maxwell

While I am a strong proponent of low-cost, human-scale mobile manipulators, I also realize it's impractical for everyone to be playing with such large robots. Earlier this year I designed a small robot using an iRobot Create, some custom ABS, a Kinect, and an AX-12 based arm and neck. This small mobile manipulation platform had no name for some time, but every time I showed it to people they exclaimed "Oh! A mini version of Maxwell!". And so, this robot got the name "Mini Maxwell".


There are now about half a dozen Mini Maxes running around across the United States. As our software development is starting to calm down, I thought I would take a moment to showcase a few of the robot's features.

As you probably have guessed, this robot runs ROS (on a netbook). We're using an ArbotiX to control the arm and neck servos (7 AX-12s total), while the Create base connects directly to the netbook. Two demo buttons are attached through the ArbotiX allowing users to quickly add user input to programs.


The arm has 4 degrees of freedom, losing the wrist roll found in Maxwell. A single servo gripper is installed, although a more sophisticated one is in the works:


I demoed Mini Max earlier this week at the HBRC meeting, showing how we can easily move around toy blocks. I've posted a number of tutorials and other documentation on the ROS wiki as well.

-Fergs