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AIC Seminar Series

Programming Robotic Agents: A Multi-tasking Teleo-Reactive Approach

Keith ClarkImperial College[Home Page]

Notice:  Hosted by Richard Waldinger.

Date:  Tuesday, April 8th 2014 at 4:00pm

Location:  EK255 (SRI E building)  (Directions)


VTC available for San Diego upon request.

This talk will present a multi-threaded/multi-tasking message communicating robotic agent architecture that extends Nilsson’s Triple Tower architecture [Nilsson, 2001], which had its single task behaviour programmed using his Teleo-Reactive procedures (TR).

In the multi-tasking architecture the agent’s tasks use and share one or more robotic resources, for example several mobile robots, or robotic arms. The concurrently executing tasks are programmed in TeleoR, a major extension of TR.

TeleoR has: parallel execution of resource actions, sequences of time limited durative actions, and while and until rules that temporarily inhibit the firing of certain other rules while a condition holds, or until a condition holds. The most important extension is the concept and use of task atomic procedures to control the non-overlapping use of robotic resources by an agent's concurrent tasks.

For the agent’s belief store inference from the rapidly changing percept facts, and more slowly changing told facts, we use a flexibly typed and moded logic+functional language QuLog. Compile time analysis ensures that the action of each TeleoR guard -> action rule will be fully instantiated and correctly typed if the rule is fired, something not guaranteed in TR, but essential for controlling robotic resources.

The talk will include simulated demos of TeleoR programmed agents one of which can be seen at

N. J. Nilsson, Teleo-Reactive programs and the triple-tower architecture. Electronic Transactions on Artificial Intelligence, 5:99-110, 2001.

   Bio for Keith Clark

Keith Clark has been associated with the Department of Computing, Imperial College, since 1975 and has been a Professor of Computational Logic there since 1987. He is now Emeritus and a Visiting Professor at the University of Queensland (since 1990), and at Royal Holloway College, London (since 2009). He has given courses as a Visiting Professor at UC Santa Cruz (1976), Syracuse (1980) and Stanford (1988).

His early research at Imperial was in the theory and pragmatics of logic programming of which the most notable outputs were: the "Negation as Failure" paper giving a declarative semantics to Prolog’s not operator; IC-Prolog, an entirely declarative logic programming language developed with Frank McCabe and Steve Gregory. It had a separate layer of control annotations on the logic rules allowing an algorithm=logic+control approach to programming, as advocated by Kowalski.

He then moved into the area of concurrent logic programming and was a consultant for and reviewer of the Japanese Fifth Generation Project in the 1980s. Their GHC language was very close to Parlog, developed with Steve Gregory at Imperial. Parlog imported ideas from Hoare’s CCS language into logic programming.

In 1980, with Frank McCabe, he set up Logic Programming Associates to develop Prolog systems for personal computers. The most user friendly and widely used was MacProlog, for the early Apple Macs.

Since 1990 his interests have moved to more general multi-threaded programming languages, still with a declarative emphasis, and their use for developing multi-agent systems and cognitive robotics applications.

The output of the last 24 years research has been a series of high-level symbolic programming languages developed in collaboration with Frank McCabe and Peter Robinson.

The latest languages are TeleoR, a multi-tasking extension of Nilsson’s Teleo-Reactive robotic agent programming language, and QuLog, a flexibly typed higher order logic + function + action rule language used for the agent reasoning, task forking and inter-agent communication.

Research proposals are being written to use this language combination for collaborative agent control of small aircraft drones, and for ambient intelligence behaviour monitoring and robotic device assistance for elderly people.

Selected papers can be down-loaded from the web page:

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