共查询到19条相似文献,搜索用时 125 毫秒
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为更好地研究使用抗流量饱和液压系统(LUDV)控制的挖掘机动臂的工作特性,对LUDV系统及其使用的负载补偿多路阀进行建模和分析,在多体动力学仿真软件Simulation X中建立动臂阀联的多体动力学模型,研究了多路阀动臂阀联的通流面积特性及其在空载工况下的运行特性。研究表明多路阀动臂阀联通流面积与其适用的液压缸油腔面积一致,其设计可以满足控制要求,但在大惯性工况下使用该阀会存在压力波动。 相似文献
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分析了液压挖掘机基于与负载压力无关流量分配(LUDV)多路阀的电液流量匹配控制(EFMC)系统的控制原理,建立了EFMC系统的液压挖掘机虚拟样机模型,采用实时检测油缸速度信号的反馈闭环控制方法提高流量匹配的精度。分别建立液压挖掘机EFMC系统动力学模型与液压系统模型并根据其实际工况进行联合仿真,研究了挖掘作业过程动态特性及节能特性。与传统的基于LUDV的负载敏感系统实验结果进行对比,结果表明: EFMC系统与传统负载敏感系统相比,改善了系统的动态响应特性和稳定性,泵的压力裕度明显减小,提高了系统的节能性,反馈闭环控制系统动态响应特性也明显得到提高。研究方法可为进一步研究挖掘机的动态性、节能性、稳定性提供理论依据和参考。 相似文献
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主要围绕负载敏感LUDV系统阀后补偿实现方式的工作原理和系统特性为研究对象,针对负载敏感LUDV系统在工程机械中的典型应用,通过建立负载敏感系统及阀后补偿阀的仿真模型,分析了系统在饱和、非饱和流量和变负载工况参数对系统性能的影响,掌握了阀后压力补偿阀在负载敏感系统中的工作特性,并根据负载的变化分析了系统在饱和与非饱和流量状态下的系统特性。 相似文献
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针对液压挖掘机中使用的LUDV控制系统,利用AMESim软件建立了该系统的仿真模型,并对其负载特性做了计算,获得节流阀进出口压差、流量、脉动及效率等特性曲线,最终验证了LUDV系统的控制特性。通过对其负载特性的分析得出:在多负载且系统压差增大时,LUDV系统的脉动增大、效率降低。 相似文献
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以125MN挤压机为背景,针对用于125MN挤压机活动横梁速度控制的原有节流系统,存在阀的稳定性差,控制精度不高的缺点,提出一种以电液比例控制阀为先导阀并带位移传感器和压力传感器的新型大通径(80mm)水节流阀,对该阀阀芯位置控制原理、流量特性、控制策略以及先导阀-节流阀系统动态特性进行研究;并采用状态空间法建立了节流阀阀芯位移控制系统的数学模型,用Simulink对该模型进行仿真,得出该系统在输入为一阶跃信号下的节流阀阀芯的位移动态响应曲线和速度动态响应曲线,并分析该节流阀在实际应用过程中的动态响应特性;得出了节流阀阀心位置控制系统仿真模型的响应时间和超调量,以及在实际应用过程中的响应时间和超调量. 相似文献
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The work-class remotely-operated-underwater-vehicles(ROVs) are mainly driven by hydraulic propulsion system,and the effeciency of hydraulic propulsion system is an important performance index of ROVs.However,the efficiency of traditional hydraulic propulsion system controlled by throttle valves is too low.Therefore,in this paper,for small and medium ROVs,a novel propulsion system with higher efficiency based on high speed on/off valve control hydraulic propeller is proposed.To solve the conflict between large flow rate and high frequency response performance,a two-stage high speed on/off valve-motor unit with large flow rate and high response speed simultaneously is developed.Through theoretical analysis,an effective fluctuation control method and a novel pulse-width-pulse-frequency-modulation(PWPFM) are introduced to solve the conflict among inherently fluctuation,valve dynamic performance and system efficiency.A simulation model is established to evaluate the system performance.To prove the advantage of system in energy saving,and test the dynamic control performance of high speed on/off valve control propeller,a test setup is developed and a series of comparative experiments is completed.The smimulation and experiment results show that the two-stage high speed on/off valve has an excellent dynamic response performance,and can be used to realize high accuracy speed control.The experiment results prove that the new propulsion system has much more advantages than the traditional throttle speed regulation system in energy saving.The lowest efficiency is more than 40%.The application results on a ROV indicate that the high speed on/off valve control propeller system has good dynamic and steady-state control performances.Its transient time is only about 1 s-1.5 s,and steady-state error is less than 5%.Meanwhile,the speed fluctuation is small,and the smooth propeller speed control effect is obtained.On the premise of good propeller speed control performance,the proposed high speed on/off valve control propeller can improve the effeciency of ROV propulsion system significantly,and provides another attractive ROV propulsion system choice for engineers. 相似文献
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PILOT LEAKAGE'S INFLUENCES ON THE PERFORMANCES OF EXTRA HIGH PRESSURE PROPORTIONAL PNEUMATIC VALVE 总被引:3,自引:0,他引:3
Chen Yize Wang Xuanyin Xu Zhipeng Tao Guoliang State Key Laboratory of Fluid Power Transmission Control Zhejiang University Hangzhou China 《机械工程学报(英文版)》2005,18(2):208-211
A mathematic model is built up to analyze the influences of a pilot valve's leakage on the performances of pneumatic pressure proportional valve, and the performances are simulated by using MATLAB. The results indicate that using slide pilot valve in the valve system is feasible, but the leakage's influences can not be neglected, especially it may induce instability in a low output pressure situation. A pilot valve using too large throttle window will cause the valve oscillate. To improve the working condition of pilot valve, a method adopting different widths of two throttle window is proposed. According to our simulation, this method balances the pressure drop between the two stage throttle ports, and reduces the influences of pilot valve's leakage. 相似文献
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本文介绍了负荷传感与LUDV液压系统,分析了在单泵多执行机构时负荷传感与LUDV液压系统的工作特点,并在此基础上建立了负荷传感变量泵、负荷传感液压系统与LUDV液压系统的AMESim模型,进行了仿真分析。 相似文献
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运用Solidworks软件及COSMOSFLOwwoRKS软件包,对节流阀阀瓣进行调节特性仿真,同时绘制出了阀瓣的内部特性曲线,为设计提供可靠的参数。 相似文献
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进出口独立控制液压挖掘机回转系统运行特性* 总被引:3,自引:0,他引:3
传统液压挖掘机回转系统是由单自由度的四边联动的多路阀控制,导致其可控性较差,能耗较大。针对这一问题,提出采用泵阀复合、压力流量匹配的进出口独立的回路原理,控制液压挖掘机回转系统,液压马达两腔的压力和流量可以根据不同的工况进行独立调节。建立液压挖掘机回转系统机械结构多体动力学与电液系统联合的数字样机,利用该样机对所提出系统的可行性进行验证,针对回转系统大惯性的特点,分别对启动阶段和制动阶段制定相应的控制策略,仿真结果表明系统运行平稳。在此基础上,进一步构建基于上述原理的试验系统,并与LUDV系统试验结果进行对比,试验结果表明采用泵阀复合进出口独立控制方法能耗降低25.5%~35.6%,阀口压力损失减小50%,显著抑制上车摆动现象。 相似文献