Let's Make Robots!

Maxwell, A Mobile Manipulator

Navigation, object manipulation, other mobile manipulation research tasks.

Maxwell is my latest attempt at a lowcost, human-scale mobile manipulator using an ArbotiX and ROS. The design guidelines were pretty straight forward: it needed an arm that could manipulate things on a table top, a Kinect for primary sensor on the head, and a mobile base that kept all that stuff upright. Additionally, I wanted the robot to be easy to transport and/or ship.

Maxwell sports a larger 16x16" version Armadillo base with motors that should support a 20lb payload at speeds up to 0.5m/s. Not shown in these images is a Hokuyo URG-04LX-UG01 which will be mounted on the base, just in front of the column. The head has two AX-12 servos for pan and tilt. Eventually, the head will include a shotgun microphone.

Maxwell's arm is constructed from 2 EX-106 (shoulder lift and elbow flex), 2RX-64 (shoulder pan and wrist flex), and and 3 AX-12s (one for wrist roll, and two to form a gripper). In all honesty, it only needs the one EX-106 in the shoulder, but I didn't have any brackets that fit the RX-64 at the moment. The actual gripper fingers are temporary, I have much better ones in the works.

His central column consists of 3 sections of 8020 aluminum support, allowing all pieces to break into lengths under 20" long. This allows Maxwell to be disassembled and put into a reasonable size Pelican case for shipping. It only takes about 5 minutes to break down or setup Maxwell, as you only have to loosen 6 screws.

Maxwell will be competing in the AAAI Small Scale Manipulation Challenge later this summer. After the AAAI event, he'll probably get an upgrade for a vertical lift on the arm (similar to the one on Georgia Tech's EL-E) and possibly a conversion to two more anthropomorphic arms.

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Nice robot mikef.

Does the Armadillo or motor controller support a higher frequency PWM?  It might cut down on the noise if you make it > 60K.

Thanks. That's an excellent thought by the way, I actualy can increase the PWM rate, I'll try that out tomorrow (hadn't really thought about trying to reduce the noise up to now).

Saw this robot on youtube while searching for ROS robots. Now its here. Small world it is. Nice robot btw.

Was it hard/long to set ROS up ? Did you do it all by your self?

I've now been using ROS for about a year. It takes a bit of time to get up to speed, but once you do, it's a fantastic framework. The ArbotiX-ROS bridge that I've created has been in development since about October, the latest version being a ground up re-write starting in January.

Maxwell has been my master's project, and was 100% designed, assembled and funded by me. The drivers for connecting to hardware are my creation. The navigation system is the one provided by ROS. I've been extensively using OpenCV and the Point Cloud Library for perception.