An interval observer for uncertain continuous‐time linear systems

To design robust interval observers for uncertain continuous‐time linear systems, a new set‐integration approach is proposed to compute trajectory tubes for the estimation error. Because this approach, the order‐preserving condition on the dynamics of the estimation error is no longer required. Therefore, synthesis methods can be used to compute observer gains that reduce the impact of the system uncertainties on the accuracy of the estimated state enclosures. The performance of the proposed approach is showcased through illustrative numerical examples.     

Polynomial filtering for nonlinear stochastic systems with state‐ and disturbance‐dependent noises

This article is concerned with the polynomial filtering problem for a class of nonlinear stochastic systems governed by the Itô differential equation. The system under investigation involves polynomial nonlinearities, unknown‐but‐bounded disturbances, and state‐ and disturbance‐dependent noises ((x,d)‐dependent noises for short). By expanding the polynomial nonlinear functions in Taylor series around the state estimate, a new polynomial filter design method is developed with hope to reduce the conservatism of the existing results. In virtue of stochastic analysis and inequality technique, sufficient conditions in terms of parameter‐dependent linear matrix inequalities (PDLMIs) are derived to guarantee that the estimation error system is input‐to‐state stable in probability. Moreover, the desired polynomial matrix can be obtained by solving the PDLMIs via the sum‐of‐squares approach. The effectiveness and applicability of the proposed method are illustrated by two numerical examples with one concerning the permanent magnet synchronous motor.     

干扰床分选机分选磷矿规律的试验研究

文中分析了我国丰富的磷矿资源及传统的分选磷矿方法,阐述了研究干扰床分选机分选磷矿的规律具有重要意义,研究设计了试验室干扰床分选机分选系统,试验采用宜昌某磷矿原矿中0~3.0mm粒度的粗矿泥进行试验研究,分析了干扰床分选机分选磷矿的规律,找出了分选最佳工况点并进行了对比曲线分析,论证了显著的经济效益和广阔的市场前景。     

A new controller for boost dc–dc converters based on a novel sliding surface

ABSTRACT

In this paper, two control schemes for boost converters affected by uncertainties in input voltage and load are proposed. The boost converter dynamics is redefined in terms of new state variables to facilitate the use of a disturbance observer that can estimate matched and unmatched disturbances. A sliding surface, which is new in the context of boost converters, is proposed to enable tracking and regulation of output voltage without requiring measurement of input voltage and load current. The stability of the overall system including the disturbance observer, the sliding variable and the output is proved. The performance of the schemes is assessed for regulation of output voltage and tracking of reference voltage by simulation as well as experimentation in which various types of uncertainties and various types of reference voltages are considered.     

煤油气共生矿井底板油型气赋存特征及防治

为了提高煤油气共生矿井油型气灾害治理的科学性，以黄陵二矿为例，采用现场测试、钻探取芯、跟踪观测、地质分析等多种方法，研究了采掘工作面煤层底板油型气分布特征、涌出规律和运移机理，并初步探讨了底板油型气体灾害防治措施。结果表明:底板油型气涌出点多位于底板砂岩储层上倾尖灭端和砂岩透镜体附近，呈现不连续区带状分布特征，涌出的油型气主要来自富县组砂岩层，涌出的动力主要为地层流体压力差，底板油型气通过地层中存在大量的断裂和裂缝、微裂缝系统进入采掘空间，采掘扰动是底板油型气异常涌出的工程诱导因素。建议加强油型气综合探查技术、油型气灾害预测预报技术、油型气综合抽采技术和智能化矿井建设等方面的研究。     

开采扰动对中关铁矿堵水帷幕稳定性影响的数值模拟研究

注浆堵水帷幕技术在矿山基建和生产期可有效地堵截地下水而被众多大水矿山采用,矿山开采的同时需疏干堵水帷幕内围岩中的地下水,为探究疏干排水后开采扰动对堵水帷幕稳定性的影响规律,以中关铁矿堵水帷幕为研究对象,在详细分析矿区地质资料、帷幕内外水位变化规律的基础上,建立堵水帷幕三维地质、力学模型,采用数值模拟方法,分析疏干排水与开采扰动联合作用对堵水帷幕稳定性的影响。结果表明,堵水帷幕与强渗透性围岩接触区域及刚度与围岩差异较大区域,易形成高应力集中区;疏干排水与开采扰动联合作用对堵水帷幕、堵水帷幕与围岩接触区域应力场分布具有显著影响,矿床开采边界距帷幕越近,影响越显著。研究结果可为堵水帷幕稳定性监测提供依据。     

煤与瓦斯突出实时监测预警系统声—电噪声扰动分析

为了在金佳矿建立煤与瓦斯突出区域—局部动态实时监测预警系统，基于KJ838声电瓦斯系统，对11224运输巷工作面掘进周期内声发射与电磁辐射的噪声扰动进行了分析。结果表明:KJ838声电瓦斯系统能及时对巷道中的环境变化进行响应，放炮、开溜槽、开铲车等工序均会对声—电信号造成特定扰动。     

基于极点配置的推力矢量伺服系统控制策略研究

针对推力矢量伺服系统提出了一种采用状态反馈对系统极点进行配置的方法,同时采用该方法设计了Luenberger状态观测器,在此基础上实现了伺服系统的稳态控制。通过仿真和实验表明,采用该方法设计的推力矢量伺服系统的性能优于基于输出反馈的PI-陷波滤波控制的系统性能。     

基于滑模的运载器主动段俯仰通道姿控系统设计

与传统比例-积分-微分（PID）控制方法相比，滑模控制（SMC）方法可以比较容易地将不确定性纳入控制器设计中，从而增强系统的鲁棒性。探索了SMC技术在运载器主动段姿态控制中的工程应用，首先通过分析基于趋近律的SMC系统，提出了降低不连续切换项系数的需求，然后研究了基于干扰上界的SMC方法。三通道小偏差仿真结果验证了两种方法的控制效果，表明第2种控制器的鲁棒性更好，稳态误差小，同时发动机喷管摆角需求较小。     

Observer-based prescribed performance attitude control for flexible spacecraft with actuator saturation

This paper investigates the prescribed performance attitude control problem for flexible spacecraft subject to external disturbances and actuator constraints. By using a new performance function and an error transformation, the attitude control system is transformed into an error system which will be kept bounded to ensure expected dynamic and steady-state responses. Compared with the commonly used performance function, the modified one has an explicit prespecified terminal time which determines the maximum convergence time of the attitude control system. A modal observer and a disturbance observer are designed to deal with the flexible vibration and disturbances, respectively. Furthermore, when considering actuator saturation, an improved control strategy is developed with an auxiliary system utilized to compensate the saturation. The stability of the closed-loop system is analyzed by Lyapunov theory. Simulation results show the effectiveness and performance of the proposed methods.