Study On The Hydraulic Fault Diagnosis Expert System Of Full-hydraulic Vibratory Roller

Vibratory roller is a kind of important construction compacting machinery, which is widely used in the compaction of the earth, rock fill materials and road paving materials in road projects, airports and ports, mine and dams, municipal construction and other fields. Generally, construction machinery group work together on the construction site, vibratory roller fault would influence the other construction machinery cooperation, which will delay construction process and yield huge financial loss. The hydraulic system is the main system of the vibratory roller, with poor work environment and relatively complex work conditions, the hydraulic system has the higher probability of failure. It is very important to develop the fault diagnosis expert system for vibratory roller hydraulic system, which is conducive to timely eliminate fault and hidden danger, make full use of roller's maximum efficacy, and ensure construction quality and speed up construction progress,and improve economic benefit.Based on analysis of the development status of fault diagnosis technology for hydraulic systems.the implementation technology of fault diagnosis expert system for roller hydraulic systems is thoroughly studied.In this thesis, it is analyzed in the hydraulic system of a type of vibratory roller, the failure mechanism and fault diagnosis of roller hydraulic systems and hydraulic components are summarized and analyzed. The reasons for the failure and the exclusion methods of the hydraulic system and hydraulic components are summarized.The basic functions,characteristics, general structure and working principle of expert system are studied. Some key technologies of the fault diagnosis expert system are researched in depth about knowledge base,inference mechanism, search strategy,interpretation mechanism and so on.The thesis establishes a knowledge library of fault diagnosis expert system in the form of the Microsoft Access2003database. This database presents the collected fault diagnosis knowledge in the form of productive rules,and deposits the knowledge rules into the knowledge base established on the basis of database by way of forms.It makes a good use of the advantage of database management system in dealing with a great amount of information.Each function module of the expert system is built by delphi7.0platform which is object oriented and visual.The reasoning machine is designed and realized,which uses forward reasoning,the depth first search strategy and combining of certainty reasoning and uncertainty reasoning.This system has realized the common fault diagnosis of vibratory roller hydraulic system through man-machine conversation.At the end of the thesis, some conclusions are given to summarize my research of fault diagnosis techniques of vibratory roller hydraulic system. Still existing problems and shortcomings of the expert system are pointed out, recommendations on the follow-up study and work are given. In prospect, several points about the continued research of fault diagnosis techniques of roller hydraulic system are given.