Proceedings of the International Symposium on Combinatorial Search
Solving planning problems via translation to propositional satisfiability (SAT) is one of the mos... more Solving planning problems via translation to propositional satisfiability (SAT) is one of the most successful approaches to automated planning. An important aspect of this approach is the encoding, i.e., the construction of a propositional formula from a given planning problem instance. Numerous encoding schemes have been proposed in the recent years each aiming to outperform the previous encodings on the majority of the benchmark problems. In this paper we take a different approach. Instead of trying to develop a new encoding that is better for all kinds of benchmarks we take recently developed specialized encoding schemes and design a method to automatically select the proper encoding for a given planning problem instance. In the paper we also examine ranking heuristics for the Relaxed Relaxed Exists-Step encoding, which plays an important role in our algorithm. Experiments show that our new approach significantly outperforms the state-of-the-art encoding schemes when compared on ...
Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment
With more computing power available, video games may spare increasing amounts of processing time ... more With more computing power available, video games may spare increasing amounts of processing time for AI. One prospective application of the newly available resources is the simulation of large amounts of non-player characters (NPCs) in open world games. While it is relatively easy to simulate simple behaviours of individual NPCs it is much more difficult to create meaningful interactions between the NPCs. However, without interaction, the world cannot look very alive. In this paper we present a technique that enriches the NPC simulation with pre-scripted situations - short sketches involving coordinated interaction between several NPCs that do not substantially alter the state of the game world but increase the appeal of the world to the player. We use constraint satisfaction techniques to find NPCs suitable to enact the situations at runtime. We have implemented situations on top of the AI system for an upcoming AAA open-world game and show that this approach satisfies functional a...
Abstract. 1 The conventional wisdom and practice is that planning and scheduling tasks are solved... more Abstract. 1 The conventional wisdom and practice is that planning and scheduling tasks are solved separately using different methods and approaches. However, recent development in industrial planning and scheduling demands for mixing both tasks to allow modelling of wider class of problems. The purpose of this paper is to present a framework for mixing planning and scheduling tasks within single system. We analyse traditional views of planning and scheduling and we highlight the drawbacks of separating both tasks when applied to modelling complex process environments. We give some real-life examples where the mixed approach helps to model the problems and we propose a generic framework for such mixture. We also argue for using constraint programming as underlying solving technology and, finally, we describe some constraint models based on the proposed framework. Although, we concentrate on planning and scheduling in complex process environments we believe that the results contribute...
Problem Areas In general, the VisOpt scheduler is appropriate for almost all production schedulin... more Problem Areas In general, the VisOpt scheduler is appropriate for almost all production scheduling problems. In particular, we concentrate on problems where many different types of resources appear. We call such problems heterogeneous because the resources involved in the scheduling task can be of many different types, like producer, mover, store, tool, worker, etc. Actually, we include custom and purchase orders among resources because, in our terminology, resource is everything that is being scheduled. Note that the scheduling engine is (almost) independent of particular structure of resources so it is possible to extend the scheduler with other resource types.
Solving planning problems via translation to satisfiability (SAT) is one of the most successful a... more Solving planning problems via translation to satisfiability (SAT) is one of the most successful approaches to automated planning. We propose a new encoding scheme, called Reinforced Encoding, which encodes a planning problem represented in the SAS+ formalism into SAT. The Reinforced Encoding is a combination of the transition-based SASE encoding with the classical propositional encoding. In our experiments we compare our new encoding to other known SAS+ based encodings. The results indicate, that he Reinforced encoding performs well on the benchmark problems of the 2011 International Planning Competition and can outperform all the other known encodings for several domains.
Temporal Networks play an important role in solving planning problems and they are also used, tho... more Temporal Networks play an important role in solving planning problems and they are also used, though not as frequently, when solving scheduling problems. In this paper we propose an extension of temporal networks by parallel and alternative branching. This extension supports modelling of alternative paths in the network; in particular, it is motivated by modelling alternative process routes in manufacturing
Proceedings of the International Symposium on Combinatorial Search
Solving planning problems via translation to propositional satisfiability (SAT) is one of the mos... more Solving planning problems via translation to propositional satisfiability (SAT) is one of the most successful approaches to automated planning. An important aspect of this approach is the encoding, i.e., the construction of a propositional formula from a given planning problem instance. Numerous encoding schemes have been proposed in the recent years each aiming to outperform the previous encodings on the majority of the benchmark problems. In this paper we take a different approach. Instead of trying to develop a new encoding that is better for all kinds of benchmarks we take recently developed specialized encoding schemes and design a method to automatically select the proper encoding for a given planning problem instance. In the paper we also examine ranking heuristics for the Relaxed Relaxed Exists-Step encoding, which plays an important role in our algorithm. Experiments show that our new approach significantly outperforms the state-of-the-art encoding schemes when compared on ...
Proceedings of the AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment
With more computing power available, video games may spare increasing amounts of processing time ... more With more computing power available, video games may spare increasing amounts of processing time for AI. One prospective application of the newly available resources is the simulation of large amounts of non-player characters (NPCs) in open world games. While it is relatively easy to simulate simple behaviours of individual NPCs it is much more difficult to create meaningful interactions between the NPCs. However, without interaction, the world cannot look very alive. In this paper we present a technique that enriches the NPC simulation with pre-scripted situations - short sketches involving coordinated interaction between several NPCs that do not substantially alter the state of the game world but increase the appeal of the world to the player. We use constraint satisfaction techniques to find NPCs suitable to enact the situations at runtime. We have implemented situations on top of the AI system for an upcoming AAA open-world game and show that this approach satisfies functional a...
Abstract. 1 The conventional wisdom and practice is that planning and scheduling tasks are solved... more Abstract. 1 The conventional wisdom and practice is that planning and scheduling tasks are solved separately using different methods and approaches. However, recent development in industrial planning and scheduling demands for mixing both tasks to allow modelling of wider class of problems. The purpose of this paper is to present a framework for mixing planning and scheduling tasks within single system. We analyse traditional views of planning and scheduling and we highlight the drawbacks of separating both tasks when applied to modelling complex process environments. We give some real-life examples where the mixed approach helps to model the problems and we propose a generic framework for such mixture. We also argue for using constraint programming as underlying solving technology and, finally, we describe some constraint models based on the proposed framework. Although, we concentrate on planning and scheduling in complex process environments we believe that the results contribute...
Problem Areas In general, the VisOpt scheduler is appropriate for almost all production schedulin... more Problem Areas In general, the VisOpt scheduler is appropriate for almost all production scheduling problems. In particular, we concentrate on problems where many different types of resources appear. We call such problems heterogeneous because the resources involved in the scheduling task can be of many different types, like producer, mover, store, tool, worker, etc. Actually, we include custom and purchase orders among resources because, in our terminology, resource is everything that is being scheduled. Note that the scheduling engine is (almost) independent of particular structure of resources so it is possible to extend the scheduler with other resource types.
Solving planning problems via translation to satisfiability (SAT) is one of the most successful a... more Solving planning problems via translation to satisfiability (SAT) is one of the most successful approaches to automated planning. We propose a new encoding scheme, called Reinforced Encoding, which encodes a planning problem represented in the SAS+ formalism into SAT. The Reinforced Encoding is a combination of the transition-based SASE encoding with the classical propositional encoding. In our experiments we compare our new encoding to other known SAS+ based encodings. The results indicate, that he Reinforced encoding performs well on the benchmark problems of the 2011 International Planning Competition and can outperform all the other known encodings for several domains.
Temporal Networks play an important role in solving planning problems and they are also used, tho... more Temporal Networks play an important role in solving planning problems and they are also used, though not as frequently, when solving scheduling problems. In this paper we propose an extension of temporal networks by parallel and alternative branching. This extension supports modelling of alternative paths in the network; in particular, it is motivated by modelling alternative process routes in manufacturing
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