A multi-threaded architecture for cognitive robotics

Speaker: Speaker: Keith Clark, Imperial College

When: 10:00, Friday, 25 May 2007

Venue: 78-420

We describe a multi-threaded architecture combining elements of Belief, Desires, Intentions (BDI) agent architectures with the goal directed reactive control of Nilsson's Teleo Reactive (TR) programs.

TR programs are a rule based programming notation influenced by process control concepts of continuous monitoring and action, but they have parameterized procedures and rule actions can be TR procedure calls, even recursive calls. A TR procedure is also typically goal directed, the actions of its rules being oriented towards achieving a state of the environment that can be determined by some test of sensor readings. They are thus well suited to implementing robotic control where action routines are selected on the basis of the computational analysis of sensor readings .

TR computation comprises nested threads of execution, each thread being the execution of a TR procedure called from its parent thread. The TR procedures of the higher threads can be programmed to monitor beliefs, inferred from sensor readings and a model of the environment, rather than percepts. But to retain reactivity, the lower level threads can still directly test percepts computed from sensor readings. This makes it also suitable for programming hybrid deliberative/reactive robots. Finally, a topmost control thread, which decides which high level TR procedure to invoke based on significant events, such as belief updates or new goals, can be added borrowing from BDI agent architectures. This allows the robot to switch tasks based on message events or sensor reading events that lead to significant changes in the robots higher level beliefs. This is the control architecture currently being used at Imperial both for Multi-agent systems and co-operative robotics applications.

Hospitality: Peter Robinson

Contact: Robert Colvin (SSE seminar co-ordinator) (robert@itee.uq.edu.au)

SSE seminar web page: http://www.itee.uq.edu.au/~sse/Seminars.html