Automation in Handling Uncertainty in Semantic-knowledge based Robotic Task-planning by Using Markov Logic Networks (original) (raw)

Using semantic information for improving efficiency of robot task planning

… Semantic Information in …, 2007

Abstract— The use of semantic information in robotics is an emergent field of research. As a supplement to other types of information, like geometrical or topological, semantics can improve mobile robot reasoning or knowledge inference, and can also facilitate human-robot ...

Integrating Robot Task Planner with Common-sense Knowledge Base to Improve the Efficiency of Planning

Procedia Computer Science, 2013

This paper presents a developed approach for intelligently generating symbolic plans by mobile robots acting in domestic environments, such as offices and houses. The significance of the approach lies in developing a new framework that consists of the new modeling of high-level robot actions and then their integration with common-sense knowledge in order to support a robotic task planner. This framework will enable interactions between the task planner and the semantic knowledge base directly. By using common-sense domain knowledge, the task planner will take into consideration the properties and relations of objects and places in its environment, before creating semantically related actions that will represent a plan. This plan will accomplish the user order. The robot task planner will use the available domain knowledge to check the next related actions to the current one and the action's conditions met will be chosen. Then the robot will use the immediately available knowledge information to check whether the plan outcomes are met or violated.

Robot Task Planning Based on State Semantic Network

The generation of robot task planning is a challenging issue in uncertain and dynamic real world. Semantic knowledge can be used to support the task planning of robots as a source of implied knowledge. At present, many literatures elaborate semantic networks, which integrate spatial information and semantic information, and use semantic knowledge to carry out robot task planning. Aiming at the demand of automatic robot task planning, this paper improved the semantic network with the trend of the development of the current semantic network. This paper proposed a state semantic network (SSN) based on state machine and semantic network. The state semantic network is a semantic network composed of semantic objects with current state information, and the current state information of the objects in the SSN is determined by the state machine associated with the semantic network objects. In the case of reasoning based on the state semantic network objects, only when the object being reasoned and its current state satisfy the specific condition, the reasoned object can be iterated as a semantic object associated with the current object that conforms to the particular condition, and achieves further reasoning .

Mixed Logical Inference and Probabilistic Planning for Robots in Unreliable Worlds

IEEE Transactions on Robotics, 2015

Deployment of robots in practical domains poses key knowledge representation and reasoning challenges. Robots need to represent and reason with incomplete domain knowledge, acquiring and using sensor inputs based on need and availability. This paper presents an architecture that exploits the complementary strengths of declarative programming and probabilistic graphical models as a step towards addressing these challenges. Answer Set Prolog (ASP), a declarative language, is used to represent, and perform inference with, incomplete domain knowledge, including default information that holds in all but a few exceptional situations. A hierarchy of partially observable Markov decision processes (POMDPs) probabilistically models the uncertainty in sensor input processing and navigation. Nonmonotonic logical inference in ASP is used to generate a multinomial prior for probabilistic state estimation with the hierarchy of POMDPs. It is also used with historical data to construct a Beta (meta) density model of priors for metareasoning and early termination of trials when appropriate. Robots equipped with this architecture automatically tailor sensor input processing and navigation to tasks at hand, revising existing knowledge using information extracted from sensor inputs. The architecture is empirically evaluated in simulation and on a mobile robot visually localizing objects in indoor domains.

Towards an Architecture for Knowledge Representation and Reasoning in Robotics

Lecture Notes in Computer Science, 2014

This paper describes an architecture that combines the complemen- tary strengths of probabilistic graphical models and declarative programming to enable robots to represent and reason with qualitative and quantitative descrip- tions of uncertainty and domain knowledge. An action language is used for the architecture’s low-level (LL) and high-level (HL) system descriptions, and the HL definition of recorded history is expanded to allow prioritized defaults. For any given objective, tentative plans created in the HL using commonsense reasoning are implemented in the LL using probabilistic algorithms, and the correspond- ing observations are added to the HL history. Tight coupling between the levels helps automate the selection of relevant variables and the generation of policies in the LL for each HL action, and supports reasoning with violation of defaults, noisy observations and unreliable actions in complex domains. The architecture is evaluated in simulation and on robots moving objects in indoor domains.

Mixing Non-Monotonic Logical Reasoning and Probabilistic Planning for Robots

2015

This paper describes an architecture that combines the complementary strengths of probabilistic graphical models and declarative programming to represent and reason with qualitative and quantitative descriptions of domain knowledge and uncertainty. An action language is used for the architecture’s low-level (LL) and high-level (HL) system descriptions, and the HL definition of recorded history is expanded to allow prioritized defaults. For any given objective, each action in the plan created in the HL using non-monotonic logical reasoning is executed probabilistically in the LL, refining the HL description to identify the relevant sorts, fluents and actions, and adding the corresponding action outcomes to the HL history. The HL and LL domain representations are translated into an Answer Set Prolog (ASP) program and a partially observable Markov decision process (POMDP) respectively. ASP-based inference provides a multinomial prior for POMDP state estimation, and populates a Beta den...

Mixed Logical and Probabilistic Reasoning for Planning and Explanation Generation in Robotics

ArXiv, 2015

Robots assisting humans in complex domains have to represent knowledge and reason at both the sensorimotor level and the social level. The architecture described in this paper couples the non-monotonic logical reasoning capabilities of a declarative language with probabilistic belief revision, enabling robots to represent and reason with qualitative and quantitative descriptions of knowledge and degrees of belief. Specifically, incomplete domain knowledge, including information that holds in all but a few exceptional situations, is represented as a Answer Set Prolog (ASP) program. The answer set obtained by solving this program is used for inference, planning, and for jointly explaining (a) unexpected action outcomes due to exogenous actions and (b) partial scene descriptions extracted from sensor input. For any given task, each action in the plan contained in the answer set is executed probabilistically. The subset of the domain relevant to the action is identified automatically, a...

Robot task planning using semantic maps

Robotics and Autonomous Systems, 2008

Task planning for mobile robots usually relies solely on spatial information and on shallow domain knowledge, such as labels attached to objects and places. Although spatial information is necessary for performing basic robot operations (navigation and localization), the use of deeper domain knowledge is pivotal to endow a robot with higher degrees of autonomy and intelligence. In this paper, we focus on semantic knowledge, and show how this type of knowledge can be profitably used for robot task planning. We start by defining a specific type of semantic maps, which integrates hierarchical spatial information and semantic knowledge. We then proceed to describe how these semantic maps can improve task planning in two ways: extending the capabilities of the planner by reasoning about semantic information, and improving the planning efficiency in large domains. We show several experiments that demonstrate the effectiveness of our solutions in a domain involving robot navigation in a domestic environment.

ASP-POMDP: Integrating Non-monotonic Logical Reasoning and Probabilistic Planning on Mobile Robots

2012

Autonomous operation is a key challenge to the deployment of mobile robots in real-world domains such as homes and offices. The partial observability, non-determinism and unforeseen dynamic changes of these domains frequently make it difficult for robots to operate without any domain knowledge or human inputs. It is however infeasible to provide robots with all relevant domain knowledge (in advance), and humans are unlikely to have the time and expertise to provide elaborate and reliable feedback in complex domains. Our previous work enabled a team of robots to visually localize target objects using hierarchical partially observable Markov decision processes (POMDPs) [21]. Although POMDPs elegantly model the uncertainty in sensing and navigation, it is difficult to represent common sense knowledge or perform high-level reasoning with human inputs. This paper addresses these challenges by combining Answer Set Programming (ASP), a non-monotonic logic programming paradigm, with hierarchical POMDPs. Domain knowledge is represented as predicates and facts that capture the relationships between object categories, and ASP reasons with the available knowledge to initialize or revise the POMDP belief distributions. Sensory observations and human inputs cause POMDP belief updates and augment (or revise) the current knowledge modeled by ASP. All algorithms are evaluated in simulation and on mobile robots localizing targets in indoor domains.

A Refinement-Based Architecture for Knowledge Representation and Reasoning in Robotics

ABSTRACTThis paper describes an architecture that combines the complementary strengths of probabilistic graphical models and declarative programming to enable robots to represent and reason with logic-based and probabilistic descriptions of uncertainty and domain knowledge. An action language is extended to support non-boolean fluents and non-deterministic causal laws. This action language is used to describe tightly-coupled transition diagrams at two levels of granularity, refining a coarse-resolution transition diagram of the domain to obtain a fine-resolution transition diagram. The coarse-resolution system description, and a history that includes (prioritized) defaults, are translated into an Answer Set Prolog (ASP) program. For any given goal, inference in the ASP program provides a plan of abstract actions. To implement each such abstract action probabilistically, the part of the fine-resolution transition diagram relevant to this action is identified, and a probabilistic representation of the uncertainty in sensing and actuation is included and used to construct a partially observable Markov decision process (POMDP). The policy obtained by solving the POMDP is invoked repeatedly to implement the abstract action as a sequence of concrete actions, with the corresponding observations being recorded in the coarse-resolution history and used for subsequent reasoning. The architecture is evaluated in simulation and on a mobile robot moving objects in an indoor domain, to show that it supports reasoning with violation of defaults, noisy observations and unreliable actions, in complex domains.