URBI
| Developer(s) | Gostai / Aldebaran |
|---|---|
| Initial release | 2003 |
| Stable release |
2.7.4 / November 17, 2011
|
| Development status | Active |
| Written in | urbiscript, C++ |
| Operating system | Microsoft Windows, Mac OS X, Linux |
| Type | Robotics suite, OS, library |
| License | BSD licenses |
| Website | github repository [1] |
Urbi is an open source cross-platform software platform in C++ used to develop applications for robotics and complex systems. Urbi is based on the UObject distributed C++ component architecture. It also includes the urbiscript orchestration language which is a parallel and event-driven script language. UObject components can be plugged into urbiscript and appear as native objects that can be scripted to specify their interactions and data exchanges. UObjects can be linked to the urbiscript interpreter, or executed as autonomous processes in "remote" mode.
The urbiscript language has been created in 2003 by Jean-Christophe Baillie in the Cognitive Robotics Lab of ENSTA, Paris. It has been actively and further developed in the industry through the Gostai company founded in 2006. It is now an open source project, with a BSD license, available at [2].
The urbiscript language can be best described as an orchestration script language: like Lua in video games, urbiscript can be used to glue together C++ components into a functional behavior, the CPU-intensive algorithmic part being left to C++ and the behavior scripting part being left to the script language which is more flexible, easy to maintain and allows dynamic interaction during program execution. As an orchestration language, urbiscript also brings some useful abstractions to the programmer by having parallelism and event-based programming as part of the language semantics. The scripting of parallel behaviors and reactions to events are core requirements of most robotic and complex AI applications, therefore urbiscript (and the whole Urbi platform) is well suited to these applications.
The example below shows how to write a ball tracking action/perception loop in urbiscript: headYaw/headPitch are two motor objects, and ball is the ball detection object (x and y range from -1/2 to 1/2):
whenever is used to trigger a piece of code in loops as long as the associated condition is true. The "&" sign is used to specify that both commands should start at the same time, thus running in parallel.
Other notable event-driven constructs include at, which triggers the associated code once when the event is triggered:
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