【作者】 卜延鹏；

【导师】 刘顺安；

【作者基本信息】 吉林大学 ， 机械电子工程， 2008， 硕士

【摘要】 本文针对国产液压挖掘机发动机—泵恒功率匹配存在的缺陷,使发动机的功率得不到充分的利用,造成挖掘机功率利用率低的现象,提出了液压挖掘机转速感应控制系统。本文分析了国内外液压挖掘机转速感应控制系统发展现状,首先介绍了液控转速感应系统的原理并用AMESIM仿真软件对其进行了仿真分析。在此基础上,设计了电液比例换向阀实现的转速感应控制系统,建立了整个电液控转速感应系统的简化数学模型,并应用控制系统仿真软件Matlab7.0/Simulink对系统动态特性进行计算机仿真。提出了充分利用数字控制器的优势,对系统进行了PID串联校正,消除阀的控制死区,从而提高速度控制精度。最后通过试验对系统进行了检测,试验结果证明了本文设计的电液控转速感应系统方法合理、可行,对当今国内挖掘机的转速感应控制系统开发有一定的参考价值。更多还原

【Abstract】 Hydraulic excavator is a kind of multifunction earthwork engineering machinery, it is widely used in mechanized construction such as industrial and civilian constructions, transportation, water power project, farmland transformation, mines and modernization military engineering, And it is playing an increasingly prominent role in the engineering construction, are attracting increasing attention.The dissertation, aim at the deficiency of domestic excavator Engine-Pump constant power control, and it is incapable of exert engine all power, resulting in a low utilization rate excavator power phenomenon, so researching on rotate speed sensing control system of hydraulic excavator.The existing foreign hydraulic excavators had been successfully used speed sensor control system, and have achieved good results in energy efficiency. However considering domestic manufacturers are incapable of supplying high quality, high performance foundation parts and auxiliary equipment, such as the diesel engine, hydraulic components, etc, so domestic manufacturers on the production of hydraulic excavators rarely used the technology of rotate speed sensing control system. Even though some universities and corporations, like Jinlin University and Guangxi Yuchai Limited Company, have obtained outstanding achievement on rotate speed sensing control system of hydraulic excavator, but there still are biggish disparities between foreign hydraulic excavators and domestic excavators. So research on rotate speed sensing control domestic hydraulic excavator is of great significance both theoretical and experimental in strengthening competitionThis dissertation design an electronic rotate speed sensing control System of the hydraulic excavator System and the innovations are as following1. The dissertation analyzes present research situation of hydraulic excavator rotate speed sensing control system, introduces the working principles of several advanced hydraulic excavator rotate speed sensing control system, and explains the purpose and significance of research on hydraulic excavator rotate speed sensing control system.2. Introduced the principle of the rotate speed sensing control system and used AMESIM to analysis the system.3. Design on rotate speed sensing control system of the hydraulic excavator.By analyzing the electro-hydraulic proportional directional control valvestructure characteristics, put forward the innovative use of electro-hydraulic proportional directional control valve to achieve excavator rotate speed sensing control system, with electro-hydraulic proportional valve control the direction of the variable displacement control piston, adjust the tilt-variable pump corner, change the variable flow pump, achieve the absorption power of the pump always follow Engine output, then power matching are realized.4. Building the mathematics model of the control systemThe mathematics models of the rotate speed sensing system, which obtained engine, variable displacement pump, the electro-hydraulic proportional directional control valve and the control variables Pistons, were built in this paper. Opening-loop transfer function of the system is gained by simplifying the mathematics models, established the base for the simulink study.5. System simulation analysis and PID controllerThe dissertation use Matlab7.0/Simulink conducted on the system response time domain analysis and frequency response analysis, In order to be satisfied with the performance of system, it correct the system by the speed control with dead-zone PID series corrector, and the correction system has been Matlab7.0/Simulink simulation. The simulink test results indicates that PID series Correction could eliminates system static error, the system can be satisfied with the performance.6. Test-bed experiments of rotate speed sensing control systemThe test was done in the sensor sensing control system test-bed, which the aim of for verifying the design speed sensor sensing control system reliability and effects of actual control. Experiment proves, the dissertation design rotate speed sensing control system can holdregardless of motor speed control system changes, variable flow pump can be controlled by computer, so that the pump flow rate to maintain a constant output; The design of software for Delphi Computer Control System Performance stability, and complete set of control functions of the various targets quickly, accurately measured, stable and reliable.The dissertation put forward a new rotate speed sensing control system, and its reliability was proved by the experiments, it has great significance both in theory and practices on research the rotate speed sensing control system of domestic excavators.更多还原