复杂负载工况的双伺服阀控系统及控制方法研究

To improve the precision of electro-hydraulic servo systems with active and passive loads (e.g., the unbalanced mass control of artilleries, hydraulic automatic gauge control systems), a dual-servo-valve based independent chamber control scheme with both high and low oil supply pressures is proposed. Utilizing a variable pump station driven by a pressure-feedback based AC servo motor and a fixed displacement pump, a throttling dual-servo system based on dual-servo-valve control and volumetric pump control is constructed, to achieve high frequency, high precision and high efficiency of the whole system. The load of the system is estimated based on the chamber pressures of the cylinder and the prediction of the pressure change, which allows separate control of the two servo valves based on the displacement of the cylinder and the closed-loop position control of the cylinder under active and passive load conditions. Meanwhile, the parallel connection and redundancy control of the two servo valves as well as the lock of the cylinder can be achieved through shifting the four electro-magnetic ball valves on or off. Utilizing a variable pump station driven by a pressure-feedback based AC servo motor, the oil supply can be controlled in real time, leading to more stable pressure, smaller volume and improved energy efficiency. This project will primarily focus on the optimal predictive double-servo-system control strategy of the proposed dual-servo-valve based closed-loop cylinder position control scheme. Theoretic modeling, numerical simulation and stability analysis will be conducted, based on which the experiment device will be built to perform performance tests on the whole system.

针对类似火炮高低向稳定、液压压下钢板厚度自动控制等同时存在主被动负载的电液伺服系统控制精度差的问题，提出了一种高低压供油的双伺服阀独立控制油缸两腔的回路，并采用基于压力反馈的交流伺服电机驱动定量泵供油，构成节流式双阀控和容积式泵控的伺服系统，实现高频响、高精度和高效节能目的。根据油缸两腔压力和压力变化预测负载，结合油缸位置反馈分别控制两个伺服阀，实现油缸在主被动负载下的位置控制。通过油缸负载口四个电磁球阀切换，还可实现双伺服阀并联、冗余和油缸闭锁等。采用基于压力反馈的交流伺服电机驱动定量泵供油泵站，根据预测油缸运动瞬时流量实时控制输出流量，比传统恒压变量泵和蓄能器构成的泵站具有更稳定的压力、更小的体积和更好的节能效果。本项目重点研究所提双伺服阀独立控制负载口系统的预测控制、优化控制等方法，在理论建模、数字仿真、稳定性分析基础上，建立实验平台对整个系统进行验证。

电液伺服系统具有控制精度高、负载能力强、频率响应快等优点，在武器装备、成型制造、模拟试验、冶金轧钢等领域得到广泛应用。但传统阀控缸系统面对主被动负载同时存在的复杂工况，其控制性能受到限制，同时存在着发热严重，能量损失大的问题。.针对同时存在主被动负载、能量损失严重、阀控与泵控协同的双伺服系统优化控制等问题，本项目对复杂负载工况伺服油缸负载口独立控制展开研究，提出了一种双伺服阀独立驱动液压缸两腔的控制回路, 采用基于压力反馈的交流伺服电机驱动定量泵实现流量快速调节的供油泵站，构成双伺服阀控缸和恒压伺服泵的双伺服系统。.本项目主要研究了（1）基于主被动负载的负载独立口双阀节能控制系统的基本特性，分析了其静态工作点和节能特性，以及主被动负载存在的复杂负载工况。（2）研究实现了双伺服阀独立控制油缸负载口的优化控制方法，满足主被动负载工况下的高精度、高频响位置控制；（3）研究设计了交流伺服电机驱动定量泵并实现压力稳定、频响高、节能效果好的控制方法，满足了电液伺服阀控系统恒压供油需求，有效降低了能量损失。（4）研究建立了准确的双伺服阀独立控制负载口系统和恒压伺服泵站系统的双伺服系统数学模型，并设计了鲁棒自适应的解耦控制算法，并对整个系统进行了仿真分析和实验验证。.综上，通过对本项目的研究，对负载口独立双伺服阀控缸系统的特性有了基本的认识，为负载口独立控制的进一步研究打下了基础；同时实现了双伺服阀独立控制负载口系统和恒压伺服泵站系统的双伺服系统的协同控制，实现了高精度、高频响和节能的控制效果，对电液伺服系统在复杂工况下的高性能控制和节能控制具有重要启示。