大流量插装式伺服阀的设计与控制方法研究

发布时间：2018-04-27 19:00

本文选题：插装式伺服阀 + 参数匹配　；参考：《浙江大学》2013年博士论文

【摘要】：大流量插装式伺服阀是很多重大机械装备中电液控制系统的核心部件,譬如大型模锻压机、快锻压机、铝合金压铸机等,目前很大程度上还依赖于进口。在以往的研究中,关于插装式伺服阀与实际应用工况相匹配的参数设计方法、以及插装式伺服阀控制器设计的研究较少,阀的性能潜力未能得到充分挖掘,性能进一步提升受到制约。本文将围绕上述两大问题,通过理论建模、仿真分析、实验验证相结合的方法展开研究,主要内容如下：第一章,对大流量电液比例/伺服插装式节流阀的实现原理及其工程应用背景进行阐述。在分析了国内外相关技术研究现状基础上,提出了本文的主要研究内容。第二章,对插装式伺服阀结构参数优化设计方法的研究。推导了与使用工况相匹配的主动式插装伺服阀一系列结构参数的设计公式,平衡各项结构参数的相互制约关系。推导了主阀芯所受液压力和液动力的理论公式和简化计算公式,为先导控制腔的参数设计提供依据,并为后续控制器的设计提供了负载模型。第三章,对伺服比例阀的整体性建模研究。建立了电一机械转换器的集中参数模型,体现了滞环、非线性电感等常见的电磁铁非线性特征。建立了阀体机械运动部件的模型,通过直接测量与间接估算确定了各主要参数值。根据实验拟合了稳态液动力的数学模型。设计了开环和闭环两种实验测试方法,验证了模型的有效性。通过零位处的线性化方法,获取了阀的标称模型,得到其传递函数及状态空间表达式,以及各主要参数的线性化参数值及变动范围。第四章,对伺服比例阀的非线性滑模控制方法研究。根据伺服比例阀的标称模型频响曲线,分析了曲线上各渐近线方程所代表的动力学约束,推导了这些约束与阀模型参数间的函数式,以此作为后续滑模控制器设计的基础。根据阀的各参数值和阀芯行程限制,采用了基于加加速度约束下、代表时间最优阶跃响应的非线性滑模面,并据此设计了滑模控制系统。通过仿真和实验分别测试了伺服比例阀的阀芯位置闭环阶跃响应和频率响应,并与阀原始配套的模拟PID控制器作了对比,从而验证了上述滑模控制器的性能。第五章,对伺服比例阀的改进型滑模控制方法研究。针对第四章的非线性滑模控制器,分析了其不足之处,并提出了多项改进方法。引入积分器以解决滑模控制中稳态精度得不到保证的问题。提出了两种速度前馈补偿的方法,以提高阀芯的轨迹跟踪能力。采用了高/低压电源切换技术,进一步提升阀的动态响应。提出了对阀身自带的LVDT位移传感器改造的办法,提取了阀芯运动的位移、速度和加速度信号全状态反馈信号,并成功应用于滑模控制中。设计了基于加速度和加加速度联合约束下、代表时间最优阶跃响应的非线性滑模面,并设计了相应的滑模控制器,给出了应用于实时控制中的实现准则和计算流程,实现了不同负载下滑模状态的稳定性和显著增强的抗负载扰动能力。第六章,大流量插装式伺服阀的非线性控制方法研究。针对先导级伺服比例阀的频响远低于主级阀频响的特点,忽略主阀芯动态,建立了插装式伺服阀的简化三阶模型,并据此设计控制器。采用了基于模型补偿的鲁棒控制和反步控制方法(backstepping)改造系统的动力学方程、配置系统的极点；采用基于Lyapunov函数和非线性映射的自适应算法,对阀系数、泄漏等参量进行自适应估计,提高模型补偿的精确性。通过仿真分析和实验对比,验证了上述控制算法的性能。第七章,对全文的主要研究工作进行了总结。阐述了主要研究结论和创新点,并对课题的后续研究提出了展望。
[Abstract]:The large flow cartridge servo valve is the core component of the electro-hydraulic control system in many important mechanical equipment, such as large die forging press, fast forging press, aluminum alloy die-casting machine, and so on. At present, it is largely dependent on the import. In the past research, the parameter design method of the matching servo valve and the actual application condition, and the insert in the past research The design of the servo valve controller is less researched, the performance potential of the valve has not been fully excavated and the performance is further restricted. This paper will focus on the above two major problems, through the method of theoretical modeling, simulation analysis and experimental verification. The main contents are as follows:
In the first chapter, the principle and engineering application background of large flow electro-hydraulic proportional / servo throttle valve are expounded. The main research contents of this paper are put forward on the basis of the analysis of the current research status of related technologies at home and abroad.
In the second chapter, the optimization design method for the structural parameters of the plug servo valve is studied. The design formula of a series of structural parameters of the active cartridge servo valve which is matched with the working condition is derived, and the interaction between the parameters of the structural parameters is balanced. The theoretical formula and simplified formula for the hydraulic pressure and the hydrodynamic force of the main valve core are derived, and the simplified formula is derived. The parameter design of the pilot control chamber provides the basis and provides a load model for the design of the subsequent controller.
In the third chapter, the integral modeling of servo proportional valve is studied. A centralized parameter model of an electrical mechanical converter is set up, which embodies the nonlinear characteristics of the common electromagnet such as hysteresis and nonlinear inductor. The model of the mechanical moving parts of the valve body is established. The main parameters are determined by direct measurement and indirect estimation. According to the experiment, the model is fitted. The mathematical model of steady state fluid dynamic is designed. Two experimental testing methods of open loop and closed loop are designed to verify the validity of the model. By linearizing the zero position, the nominal model of the valve is obtained, the transfer function and the state space expression are obtained, and the linear parameter and the variation range of the main parameters are obtained.
In the fourth chapter, the nonlinear sliding mode control method of servo proportional valve is studied. According to the frequency response curve of the nominal model of servo proportional valve, the dynamic constraints represented by the equation of each asymptote on the curve are analyzed. The function formula between these constraints and the valve model parameters is derived, which is the basis of the design of the follow-up sliding mode controller. The parameter value and the limit of the valve core travel, the nonlinear sliding mode surface which represents the optimal step response of time is adopted under the addition of addition speed, and the sliding mode control system is designed accordingly. The closed-loop step response and frequency response of the valve core position of the servo proportional valve are tested by simulation and experiment, and the analog PID controller which is matched with the valve original is also tested. A comparison is made to verify the performance of the sliding mode controller.
In the fifth chapter, the improved sliding mode control method for servo proportional valve is studied. Aiming at the nonlinear sliding mode controller of the fourth chapter, the shortcomings of the sliding mode controller are analyzed, and a number of improvement methods are proposed. The integrator is introduced to solve the problem that the steady state precision is not guaranteed in the sliding mode control. Two kinds of speed feedforward compensation methods are proposed to improve the valve core. A high / low voltage power switching technique is used to further improve the dynamic response of the valve. A method for the transformation of the LVDT displacement sensor with the valve body is proposed, and the full state feedback signal of the displacement of the valve core motion, speed and acceleration signal is extracted, and it is successfully used in the sliding mode control. The design is based on acceleration and addition. Under the constraint of acceleration, the nonlinear sliding mode surface of the time optimal step response is represented, and the corresponding sliding mode controller is designed. The implementation criteria and calculation process applied to real-time control are given. The stability of sliding mode state under different loads and the ability to resist load disturbance are achieved.
In the sixth chapter, the nonlinear control method of the large flow cartridge servo valve is studied. Aiming at the frequency response of the pilot servo proportional valve is far lower than the frequency response of the main valve, the simplified three order model of the plug servo valve is established, and the controller is designed. The robust control and backstepping control based on the model compensation is adopted. The dynamic equation of the system is reconstructed by method (backstepping), and the pole of the system is configured. The adaptive estimation of the valve coefficients and leakage parameters based on Lyapunov function and nonlinear mapping is adopted to improve the accuracy of the model compensation. The performance of the above control algorithm is verified by simulation analysis and experimental comparison.
The seventh chapter summarizes the main research work of the paper, expounds the main research conclusions and innovations, and puts forward the prospect for further research.

【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH137.52

【参考文献】