Queequeg [from Moby Dick] is the continuation of the robot Cardea's arm. The aim of this work is to prototype a behavior based approach to controlling the joint torques of the Series-Elastic-Acuator arm.

A 2 DOF cable-differential wrist were added and a 2 DOF pan-tilt Firewire camera.

We developed simple visually reaching behaviors using our in-house Creal language which runs on the custom Stack embedded controller.

Behaviors are implemented as force controllers [joint control by virtual spring, end-force control by virtual model control]. Simple feature-based visual segmentation by color provides the perceptual cues to drive the behavior arbitration.

This project is no longer active as it was a prototype platform for Domo.

The Stack is a modular embedded control architecture. A set of robot sensor and controller boards are plugged together and connected by a RS486 bus. PIC microcontrollers on each board service sensors and motors while communicating to the master controller. The master is a Z-World Rabbit running the custom behavior-based language Creal developed by Prof. Rodney Brooks.

Queequeg utilized a custom DSP board which handled the 1khz force control loops and interfaced to the stack as yet another module.

A set of Creal behaviors commanded joint torques to the arm.

A laptop provided the visual computation.

Videos.

Queequeg tracking an object with its camera and arm.

Queequeg arbitrating force behaviors to poke an object.