Retired Robots
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Hannibal's Web Page

Hannibal and Attila

[picture of Attila

The Micro-Rover Project

Attila and Hannibal were built in the Mobot Lab in the early 1990s. They are the first robots constructed by our lab to serve as experimental platforms for autonomous planetary exploration. The robots are identical, differing only in color (Hannibal is red, Attila is gold). As can be seen in the pictures below, each is a small, six legged robot--the "progeny" of Genghis, our lab's first legged robot. (Whereas these robots are legged, current micro-rover research in our lab employs tracked robotic vehicles, such as Pebbles.)

[hannibal] [attila]

Support for this resarch was provided in part by a NASA Graduate Student Reasearcher Program Fellowship administered through the Jet Propulsion Laboratory, by Jet Propulsion Laboratory grant 959333, and by the Advanced Research Projects Agency under Office of Naval Research contract N00014-91-J-4038.

  • The Design Phase

    [hannibal leg] The design principles governing the hardware organization of Attila (and Hannibal) is covered in Colin Angle's Master's thesis, "Design of an Artificial Creature".

    The thesis covers the mechanical and electronic design of the robots, emphasizing a modular subsystem architecture. For instance, each leg, the head, and the body could be treated as a separate module complete with actuators, sensors, and a satellite microprocessor. The design and construction of these robots was challenging given the size and weight constraints of the system as well as its overall complexity. A significant amount of hardware redundancy was included in anticipation of possible failues during a mission. From a mechanical standpoint, this redundancy took the form of multiple legs--it is well known that insects can still locomote with the loss of a leg. From a sensing standpoint, redundancy took the form of complementary sensor suites. Sensory signals from different types of sensors can be combined to characterize different types of leg-terrain interaction, which is used to guide the robot's behavior. By using complementary sensor suites, if a few sensors fail over the course of a mission, the remaining sensors can still be employed for robust sensing of the environment.

    Attila and Hannibal are recognized as being among the most sophisticated autonomous robots for their size, possessing over 19 degrees of freedom, over 60 sensory inputs, and over 8 microprocessors. Naturally, with a project of this magnitude, several graduate students and staff researchers assisted in the design and construction of these robots. Even with several dedicated researchers, the design phase was lenghty--starting in the summer of 1989 and continuing until completion in June 1991.

  • The Software Phase

    [hannibal] The design principles governing the software organization of these robots is covered in Cynthia Breazeal(Ferrell)'s Master's thesis, "Robust Agent Control of an Autonomous Robot with Many Sensors and Actuators" (see publications section).

    The behavior-based software written for Hannibal and Attila addresses several issues that face legged micro-rovers.

    The software was designed to address these issues and take advantage of the modular subsystem architecture of the robot as well as its complementary sensor suites. The compelete controller represents a substantial amount of work which took place starting in June 1991 and ended in the spring of 1993.

  • The Testing Phase

    [sandbox] Our lab installed a simulated lunar environment, called the "sandbox", to test the performance of our rovers in more realistic environments. The sandbox is about 15ft long by 10ft wide and consists mostly of gravel and sand with several larger rocks interspersed throughout. The robots are required to negotiate the terrain while avoiding obstacles and hazards. This testing environment helps us assess whether or not the robot will perform adequately in scenarios which are more realistic than a typical laboratory environment can provide.

    In this picture, Prof. Rod Brooks is taking a photo op in the sandbox with Attila and Genghis.

    Attila at the Smithsonian Air and Space Museum

    Attila and Genghis were invited to a planetary rover exhibition at the Smithsonian Air and Space Museum. While at the show, Colin Angle and Cynthia Breazeal(Ferrell) had the opportunity to meet former US astronaut (and senator) John Glenn (leftmost picture).

    [astronaut] [sandbox]

    Hannibal at Death Valley

    Hannibal was invited to Death Valley by the Planetary Society to participate in a variety of micro-rover tests. The gathering was a multi-national event.

    [hannibal and rover] [ramp]

    One test (shown above) was a rendez-vous mission with the Soviet research team's planetary rover. In this test, Hannibal docks with the larger Soviet rover. As shown in the picture, Hannibal docks with the Soviet rover by climbing up a ramp onto the larger rover's back.


    Another test involved traversing rough terrain. Death Valley is a good place to conduct these tests since the terrain is very similar to the terrain a rover would encounter on Mars.

    Media Coverage

    Hannibal and Attila enjoyed quite a bit of media coverage along with the rest of the mobots in the mobot lab. Check out the Mobot Lab media page.) for a list of articles written about the Mobot Lab by the popular press.

    Related Publications