Proceedings Article•
Planning Domain + Execution Semantics: A Way Towards Robust Execution?
01 Jan 2014-
TL;DR: It is shown that the combined used of causal, temporal and categorical knowledge allows the robot to detect failures even when the effects of actions are not directly observable.
Abstract: Robots are expected to carry out complex plans in real world environments. This requires the robot to track the progress of plan execution and detect failures which may occur. Planners use very abstract world models to generate plans. Additional causal, temporal, categorical knowledge about the execution, which is not included in the planner's model, is often avail- able. Can we use this knowledge to increase robustness of execution and provide early failure detection? We propose to use a dedicated Execution Model to monitor the executed plan based on runtime observations and rich execution knowl- edge. We show that the combined used of causal, temporal and categorical knowledge allows the robot to detect failures even when the effects of actions are not directly observable. A dedicated Execution model also introduces a degree of mod- ularity, since the platform- and execution-specific knowledge does not need to be encoded into the planner.
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01 Jan 2014
TL;DR: This report documents the programme and the outcomes of Dagstuhl Seminar 14081 “Robots Learning from Experiences” with abstracts of 25 presentations given at the seminar, and of four reports about discussion groups.
Abstract: This report documents the programme and the outcomes of Dagstuhl Seminar 14081 “Robots Learning from Experiences”. The report begins with a summary comprising information about the seminar topics, the programme, important discussion points, and conclusions. The main body of the report consists of the abstracts of 25 presentations given at the seminar, and of four reports about discussion groups.
1 citations
01 Jan 2014
TL;DR: An approach to avoid the unsuccessful completion of robot’s actions by more careful description of them is proposed, which characterises the expected behaviour of the objects in both states before as well as after the execution of an action.
Abstract: Robots, which are able to carry out their tasks robustly in real world environments, are not only desirable but necessary if we want them to be more welcome for a wider audience. But very often they may fail to execute their actions successfully because of insufficient information about behaviour of objects used in the actions. In this article we propose an approach to avoid the unsuccessful completion of robot’s actions by more careful description of them. This description characterises the expected behaviour of the objects in both states before as well as after the execution of an action. The description of each state consists of conjunction of a set of spatial relations between the objects. Each of these relations captures the different aspect of the object in the corresponding states. In addition, we present how by the case of the simulation these aspects can be extended and improved autonomously.
Cites background from "Planning Domain + Execution Semanti..."
...The other drawback is that including the numerical constraints in the planning model of the action violates having a general purpose planner ([Konečný et al., 2014])....
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26 Aug 2015
TL;DR: This dissertation leverages general purpose semantic networks to derive similarity measures in a problem-independent manner and demonstrates that the task context is essential in establishing which objects are interchangeable.
Abstract: Similarity is a central cognitive mechanism for humans which enables a broad range of perceptual and abstraction processes, including recognizing and categorizing objects, drawing parallelism, and predicting outcomes. It has been studied computationally through models designed to replicate human judgment. The work presented in this dissertation leverages general purpose semantic networks to derive similarity measures in a problem-independent manner. We model both general and relational similarity using connectivity between concepts within semantic networks. Our first contribution is to model general similarity using concept connectivity, which we use to partition vocabularies into topics without the need of document corpora. We apply this model to derive topics from unstructured dialog, specifically enabling an early literacy primer application to support parents in having better conversations with their young children, as they are using the primer together. Second, we model relational similarity in proportional analogies. To do so, we derive relational parallelism by searching in semantic networks for similar path pairs that connect either side of this analogy statement. We then derive human readable explanations from the resulting similar path pair. We show that our model can answer broad-vocabulary analogy questions designed for human test takers with high confidence. The third contribution is to enable symbolic plan repair in robot planning through object substitution. When a failure occurs due to unforeseen changes in the environment, such as missing objects, we enable the planning domain to be extended with a number of alternative objects such that the plan can be repaired and execution to continue. To evaluate this type of similarity, we use both general and relational similarity. We demonstrate that the task context is essential in establishing which objects are interchangeable.
References
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Proceedings Article•
01 Jan 2009TL;DR: This paper discusses how ROS relates to existing robot software frameworks, and briefly overview some of the available application software which uses ROS.
Abstract: This paper gives an overview of ROS, an opensource robot operating system. ROS is not an operating system in the traditional sense of process management and scheduling; rather, it provides a structured communications layer above the host operating systems of a heterogenous compute cluster. In this paper, we discuss how ROS relates to existing robot software frameworks, and briefly overview some of the available application software which uses ROS.
8,387 citations
"Planning Domain + Execution Semanti..." refers background in this paper
...All modules communicate through the ROS (Quigley et al. 2009) middleware....
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...A common way to execute and monitor a plan in ROS is by using a Finate State Machine architecture (Bohren et al. 2011)....
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TL;DR: The procedure was originally programmed in FORTRAN for the Control Data 160 desk-size computer and was limited to te t ra t ion because subroutine recursiveness in CONTROL Data 160 FORTRan has been held down to four levels in the interests of economy.
Abstract: procedure ari thmetic (a, b, c, op); in t eger a, b, c, op; ¢ o n l m e n t This procedure will perform different order ar i thmetic operations with b and c, put t ing the result in a. The order of the operation is given by op. For op = 1 addit ion is performed. For op = 2 multiplicaLion, repeated addition, is done. Beyond these the operations are non-commutat ive. For op = 3 exponentiat ion, repeated multiplication, is done, raising b to the power c. Beyond these the question of grouping is important . The innermost implied parentheses are at the right. The hyper-exponent is always c. For op = 4 te t ra t ion, repeated exponentiat ion, is done. For op = 5, 6, 7, etc., the procedure performs pentat ion, hexation, heptat ion, etc., respectively. The routine was originally programmed in FORTRAN for the Control Data 160 desk-size computer. The original program was limited to te t ra t ion because subroutine recursiveness in Control Data 160 FORTRAN has been held down to four levels in the interests of economy. The input parameter , b, c, and op, must be positive integers, not zero; b e g i n own i n t e g e r d, e, f, drop; i f o p = 1 t h e n b e g i n a := h-4c; go t o l e n d i f o p = 2 t h e n d := 0; else d := 1; e := c; drop := op 1; for f := I s t e p 1 u n t i l e do b e g i n ari thmetic (a, b, d, drop);
3,848 citations
"Planning Domain + Execution Semanti..." refers background in this paper
...These bounds are updated as a result of temporal constraint reasoning, an operation which can be performed in low-order polynomial time (Dechter, Meiri, and Pearl 1991; Floyd 1962)....
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01 Jan 2005
TL;DR: A formalism for reasoning about actions that is based on a temporal logic allows a much wider range of actions to be described than with previous approaches such as the situation calculus and a framework for planning in a dynamic world with external events and multiple agents is suggested.
Abstract: A formalism for reasoning about actions is proposed that is based on a temporal logic. It allows a much wider range of actions to be described than with previous approaches such as the situation calculus. This formalism is then used to characterize the different types of events, processes, actions, and properties that can be described in simple English sentences. In addressing this problem, we consider actions that involve non-activity as well as actions that can only be defined in terms of the beliefs and intentions of the actors. Finally, a framework for planning in a dynamic world with external events and multiple agents is suggested.
2,631 citations
"Planning Domain + Execution Semanti..." refers methods in this paper
...We model temporal relations between fluents as constraints in Allen’s Interval Algebra (IA) (Allen 1984)....
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TL;DR: In this article, a formalism for reasoning about actions is proposed that is based on a temporal logic, which allows a much wider range of actions to be described than with previous approaches such as the situation calculus.
2,439 citations
TL;DR: It is shown that the STP, which subsumes the major part of Vilain and Kautz's point algebra, can be solved in polynomial time and the applicability of path consistency algorithms as preprocessing of temporal problems is studied, to demonstrate their termination and bound their complexities.
1,989 citations
"Planning Domain + Execution Semanti..." refers background in this paper
...The STP maintains a time bound [se, sl] for the start of ψ consisting of earliest possible start time se and latest possible start time sl....
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...A STP maintains a lower and an upper bound for each time point (start or finish time of a fluent)....
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...Such a network can be transformed into a Simple Temporal Problem — STP (Dechter, Meiri, and Pearl 1991)....
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...These bounds are updated as a result of temporal constraint reasoning, an operation which can be performed in low-order polynomial time (Dechter, Meiri, and Pearl 1991; Floyd 1962)....
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