NASA, MBARI and Willow Garage collaborate to apply open source automated planning technology to robots roaming the home planet

Ames MBARILast year, NASA and MBARI released two important automated planning technologies to the open source community: EUROPA and TREX. The Extensible Universal Remote Operations Planning Architecture (EUROPA). EUROPA is used for a variety of different mission planning and scheduling applications, and has been demonstrated in advanced technology demonstrations for control of autonomous robots and spacecraft. TREX (using EUROPA) was pioneered at the Monterey Bay Aquarium Research Institute (MBARI) to empower Autonomous Underwater robotic explorers to make their own decisions in pursuit of science goals. We've been working to bring these open source technologies closer to home: personal robots.

Recently, TREX and EUROPA were able to demonstrate their robust capabilities as we used them to achieve our first major milestone. A PR2 robot navigated a busy office environment autonomously for two days in a row, each day doing PI kilometers. The only intervention was to plug in and unplug the robot at its request. TREX, using EUROPA, was provided a set of way-points, a charging station, and a high-level goal to pursue way-points selected at random, indefinitely. The robot would reactively pre-empt goals in order to recharge based on a simple check of battery levels. This would prompt it to navigate to the charging station and initiate a behavior to recharge itself, which involved e-mailing for help to plug in and unplug when done. When recharged, it would resume the pre-empted goal. It also handled situations like re-planning after a failure, or terminating goals that have run out of time. Lower-level controllers integrated path planners for global path planning and trajectory controllers for velocity control. TREX and EUROPA ran continuously for about 24 hours without a problem.

Our second milestone will up the ante. This time the PR2 will have to run for longer (a marathon), plugging and unplugging itself; and getting in and out of offices with closed doors. In keeping with the open-source philosophy underpinning this collaboration, all technology advances made to meet this challenge will be freely available.

EUROPA is freely available under NASA Open Source Agreement (NOSA) and can be downloaded from

TREX is freely available under a New BSD license and can be downloaded from


-- Conor McGann