Super-twisting estimator based velocity-free robust tracking control of electro-hydraulic actuators

This article develops a high-precision tracking control without velocity measurement for electro-hydraulic actuators subject to mismatched and matched disturbances. Compared with previous studies, the presented control method is attractive from a practical point of view. First, velocity signal is often approximately derived by numerical differentiation on position signal, nevertheless, accompanied heavy noise will severely deteriorate tracking performance. Thus, to avert using noise-polluted velocity signal, a third-order super-twisting algorithm (STA) is developed to achieve velocity estimation. Second, the STA-based disturbance estimator is employed to estimate and compensate mismatched and matched disturbances in finite time. Then a composite STA-based control law is constructed to achieve a velocity-free high-performance tracking control, in which an employed modified STA only with an adjustable gain is easier to be performed for practical implementation. The stability analysis reveals the proposed controller is asymptotically stable while existing time-variant disturbances. Comparative experiment results validate the superiority of the presented method.     

水下控制系统技术在采油树先导试验中的应用

为增加国产化水下采油树控制系统的可靠性和可操作性，对水下控制系统方式进行比较分析，选择电液复合控制方式作为先导试验的控制方法。目标油田流花11-1采用直接液压控制系统，需要在直接液压控制方式的基础上对其进行适应性改造。对目标油田直接液压控制系统进行调研，在充分利用原设备的基础上，在尽可能减少半潜式平台改造和施工的前提下，对国产水下采油树电液复合控制系统新增的电气系统、通信系统、液压系统、化学药剂系统等进行设计研究分析，通过4个专项计算分析，分析结果满足电液复合控制系统要求，从而论证了设计方案的可行性。     

电液伺服试验机的QFT控制研究

由于电液伺服试验机系统内存在较强的时变特性和非线性,并且试件等负载特性经常变化,导致系统存在很大的参数不确定性.当被控系统的参数等特性发生变化时,采用固定参数的传统PID控制难以获得满意的控制效果,如果重新调整参数又极大地增加了控制操作的复杂性.为解决此问题,采用定量反馈理论(QFT)的控制器设计方案,对电液伺服试验机...