Abstract
Teleo-Reactive (TR) robotic agent programs comprise sequences of guarded action rules clustered into named parameterised procedures. Their ancestry goes back to the first cognitive robot, Shakey. Like Shakey, a TR programmed robotic agent has a deductive Belief Store comprising constantly changing predicate logic percept facts, and knowledge facts and rules for querying the percepts. In this paper we introduce TR programming using a simple example expressed in the teleo-reactive programming language TeleoR, which is a syntactic extension of QuLog, a typed logic programming language used for the agent’s Belief Store. We give a formal definition of the regression property that rules of TeleoR procedures should satisfy, and an informal operational semantics of the evaluation of a TeleoR procedure call. We then formally express key features of the evaluation in LTL. Finally we show how this LTL formalisation can be used to prove that a procedure’s rules satisfy the regression property by proving it holds for one rule of the example TeleoR program. The proof requires us: to formally link a TeleoR agent’s percept beliefs with sensed configurations of the external environment; to link the agent’s robotic device action intentions with actual robot actions; to specify the eventual physical effects of the robot’s actions on the environment state.
Dongol is supported by EPSRC Grants EP/R019045/2, EP/R032556/1 and EP/R025134/2.
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Notes
- 1.
QuLog actually has another rule type, imperative action rules for defining multi-threaded agent behaviour. They can call primitive actions for forking threads, updating Belief Store facts and message communication. The two thread architecture is implemented using these action rules.
- 2.
Of course, in reality, there are environments that could impede a robot’s motion—we do not make any claims about correctness of our implementation for such environments. In a full development, one would need to make sure that the physical environment in which a verified robot operates does indeed conform to any assumptions made in the proof.
References
Clark, K.L., Robinson, P.J.: Robotic agent programming in TeleoR. In: Proceedings of International Conference of Robotics and Automation. IEEE (2015)
Clark, K.L., Robinson, P.J.: Chapter 3: introduction to QuLog. In: Programming Communicating Robotic Agents: A Multi-tasking Teleo-Reactive Approach. Springer (2020). (To appear)
Dongol, B., Hayes, I.J.: Rely/Guarantee reasoning for teleo-reactive programs over multiple time bands. In: Derrick, J., Gnesi, S., Latella, D., Treharne, H. (eds.) IFM 2012. LNCS, vol. 7321, pp. 39–53. Springer, Heidelberg (2012). https://doi.org/10.1007/978-3-642-30729-4_4
Dongol, B., Hayes, I.J., Robinson, P.J.: Reasoning about goal-directed real-time teleo-reactive programs. Formal Asp. Comput. 26(3), 563–589 (2014). https://doi.org/10.1007/s00165-012-0272-1
Jones, J., Roth, D.: Robot Programming: A Practical Guide to Behavior-based Robotics. McGraw-Hill, New York (2004)
Kamali, M., Linker, S., Fisher, M.: Modular verification of vehicle platooning with respect to decisions, space and time. In: Artho, C., Ölveczky, P.C. (eds.) FTSCS 2018. CCIS, vol. 1008, pp. 18–36. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-12988-0_2
Levesque, H.: Thinking as Computation. MIT Press, Cambridge (2012)
Mataric, M.J.: The Robotics Primer. MIT Press, Cambridge (2007)
Quigley, M., et al.: ROS: an open-source Robot Operating System (2009). www.robotics.stanford.edu/~ang/papers/icraoss09-ROS.pdf
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We thank our anonymous FMAS reviewers for their careful readings of this paper and comments, which have helped improve quality overall.
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Clark, K., Dongol, B., Robinson, P. (2020). Temporal Logic Semantics for Teleo-Reactive Robotic Agent Programs. In: Sekerinski, E., et al. Formal Methods. FM 2019 International Workshops. FM 2019. Lecture Notes in Computer Science(), vol 12232. Springer, Cham. https://doi.org/10.1007/978-3-030-54994-7_19
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