Research On Intelligent Query Knowledge Base System Of Vehicle Navigation

Query function in Vehicle Navigation System (VNS) aims to be uses' traveling decision-making assistance by providing information of spatial objects. At present, query for route planning of certain destination and basic attribute information of spatial objects become emphasis of research. As for travelers driving by themselves or traveling by cars, these kinds of query function has faultiness: one is the small amount of information, lacking of sufficient information about other spatial objects besides traveling sights, such as eating, living andpurchasing places;the other is the unintelligence of query function------the simple searchingin data base can't synthetically take multiattribute of spatial objects into account to fulfill users' individual query demand.For reasons above, the knowledge engineering theory is combined with GIS for purpose of providing enough information and intelligent query for users in vehicle terminals. Mechanism of intelligent query, query rules and inference engine are studied based on the analysis of multiattribute of spatial objects and a prototype system of intelligent query knowledge base is realized for monitoring center of VNS. The main research of this paper is as follows:(1) Overall analysis of many aspects of intelligent query knowledge base system has (IQKBS) been undertaken, such as definition, functional demand and information demand. All these offer foundations for construction of IQKBS.(2) Mechanism of intelligent query is brought out according to the characters of spatial objects' attributes in the range of query: on the basis of measuring query demand and the attributes of spatial objects by quantity, the knowledge of intelligent query is presented by production rules with confidence degree. The grouping and granularity subdivision of rules is undertaken and the rules finally are stored in relational database;the hierarchy model of IQKBS is also presented to organize the process of intelligent query and the inference engine is designed.(3) Several aspects of IQKBS are designed such as the whole structure of knowledgebase, the structure of management system of knowledge base, the mapping from attributes data base to GIS and the creation, acceptance and transmission of query results documents. Then a demonstration IQKBS is realized according to the above-mentioned contents and it turns out to be a good performance. This research provides technique support for the combination of query function in VNS and knowledge engineering theory, thus has some practical value. The realization of IQKBS advances intelligence of query function in VNS and is propitious to traveling decision-making assistant to users.