| Along with the increasing automation level, the excavator hydraulic system is developed to the direction of high performance, once the malfunction of the hydraulic system occurs, it will probably bring many harmful consequences, even catastrophic accident; affect the normal operation of the excavator. For this, the paper employs the excavator hydraulic system monitoring system that is based on virtual instrument, the real time working data on operation condition of the system will be retained, which provides the possibility for further analysis in the future.This paper first makes an in-depth and detailed analysis on loop of excavator hydraulic system, including the bucket hydraulic circuit, the big arm hydraulic circuit, the forearm arm hydraulic circuit,the working device of the hydraulic circuit and the rotary hydraulic circuit, through the analysis of excavator hydraulic system circuits, making the choice analysis of the characteristics of the excavator hydraulic system, preliminarily determining measuring points of the excavator hydraulic system.Secondly, this paper does an in-depth research on the overall scheme of condition monitoring system for the excavator hydraulic system, judging from the general structure of monitoring system, the selection of monitoring content, the function target of system, and the overall framework of the monitoring system software. The hardware monitoring system was mainly discussed; completed the analysis and selection of sensors and data acquisition card, and so on, and the anti-interference design of system hardware and software. In the process of designing software, system uses the LabVIEW software, the ideas of data flow and combines with modular design ideas to develop a set of real-time condition monitoring system of the excavator hydraulic system. To improve the real-time monitoring and avoid the phenomenon such as overflow, missing data, and the like, in the overall architecture, system adopts the structure of production consumption pattern in process of designing software, thus, the monitoring process is more reliable, and the monitoring results are more comprehensive and convincing.Then, this paper studies the key technical problems of condition monitoring system software development,including system security problems, data acquisition, data processing, data analysis, data storage problems and troubleshooting problems. In data analysis and processing module, according to the vibration signal collected, the algorithm that extract FFT depend on time to do spectrum analysis is proposed and adopted. The monitoring system has realized the real-time monitoring on the important operating conditions in the working process of excavator hydraulic system, for these exceed the threshold parameter, according to the severity, to perform three levels of pre-alarm, it also has used relational database Access and Database Connectivity Toolkit to build and do database access, including monitor all parameters database while operating in the working state and failure alarm database, providing a platform for the further adjustment and exertion in the future.Finally, through the monitoring system, it is proved to be right. Results show that, this monitoring system is stable and reliable, implies all the expected design functions perfectly and meets the requirements of the system development. |
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