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。     

河津腾晖煤业智能化降尘技术实践

以河津腾晖煤业为研究对象,基于智能化工作面开采及安全生产的需要,设计了智能化降尘系统,对该系统智能化控制关键技术进行了分析,提出了降尘点优化布置方案。该智能化降尘系统能较好地适应智能化开采技术的要求,实现了与综采智能控制系统的联动控制,降尘效果理想,为智能化开采提供了安全保障。     

基于模糊综合评判方法的水文地质类型评价

以开元矿井为例,在水文地质资料基础上,选定合适的指标,根据不同指标的重要程度确定各个指标权重,运用模糊综合评判理论建立矿井水文地质类型划分模型,运用该模型进行水文地质类型评价。     

电液控制系统关键传感器的故障预警方法研究

为了保证电液控制系统的正常运行,对电液控制系统核心传感器部件的故障预警是关键一环,分析了传感器在电液控制系统的工作原理,得到了传感器在系统中的故障规律,为了对井下的电液控制系统中的核心传感器的故障进行预警和诊断,结合目前比较流行的传感器故障预警方法,以液压支架的压力传感器为例,提出了一个静态分析与动态分析融合的诊断方法,其核心是通过对传感器采集的数据进行分析,能有效预测压力传感器故障,提高电液控制系统的可靠性。     

Reference governors and maximal output admissible sets for linear periodic systems

ABSTRACT

In this paper, we consider the problem of constraint management in Linear Periodic (LP) systems using Reference Governors (RG). First, we introduce the periodic-invariant maximal output admissible sets for LP systems. We extend the earlier results in the literature to Lyapunov stable LP systems with output constraints, which arise in RG applications. We show that, while the invariant sets for these systems may not be finitely determined, a finitely-determined inner approximation, which is periodically invariant, can be obtained by constraint tightening. We then analyze the geometric and algebraic relationship between these sets and show that these sets are related via simple transformations, implying that it suffices to compute only one of them for real-time applications. This greatly reduces the memory burden of RG (or other similar constraint management strategies), at the expense of an increase in processing requirements. We present a thorough analysis of this trade-off. In the second part of this paper, we present two RG formulations, and discuss their properties and algorithms for their computation. Numerical simulations demonstrate the efficacy of the approach.     

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。     

Optimal inspection for randomly triggered hidden deterioration processes

This paper deals with degradation processes whose onset is triggered at a random time and which stay hidden until they are discovered through inspection or when they begin to show symptoms. This is applicable in many healthcare and industrial scenarios, for example, in the modeling of breast cancer or termite infestation. In our model, we assume that symptoms appear after hitting a random critical threshold and that inspections may have a sensitivity less than one as well as a nonzero false positive rate. The expected cost of repair is derived, and the inspection rate is optimized for a cycle (which lasts from degradation-free to repaired state). This gives results for three cases: the first is for a finite observation period with no degradation recurrence, the second for infinite time horizon allowing recurrence. In the third case, we derive an upper bound for the expected cost in a given constant time period. Finally, the model is applied to determine the optimal strategy for breast cancer screening with regard to the effects of different parametrizations.     

Progress of Air Pollution Control in China and Its Challenges and Opportunities in the Ecological Civilization Era

China’s past economic growth has substantially relied on fossil fuels, causing serious air pollution issues. Decoupling economic growth and pollution has become the focus in developing ecological civilization in China. We have analyzed the three-decade progress of air pollution controls in China, highlighting a strategic transformation from emission control toward air quality management. Emission control of sulfur dioxide (SO₂) resolved the deteriorating acid rain issue in China in 2007. Since 2013, control actions on multiple precursors and sectors have targeted the reduction of the concentration of fine particulate matter (PM_2.5), marking a transition to an air-quality-oriented strategy. Increasing ozone (O₃) pollution further requires O₃ and PM_2.5 integrated control strategies with an emphasis on their complex photochemical interactions. Fundamental improvement of air quality in China, as a key indicator for the success of ecological civilization construction, demands the deep de-carbonization of China’s energy system as well as more synergistic pathways to address air pollution and global climate change simultaneously.     

Adaptive neuro-fuzzy algorithm applied to predict and control multi-phase flow rates through wellhead chokes

A Takagi-Sugeno adaptive neuro-fuzzy inference system (TSFIS) model is developed and applied to a dataset of wellhead flow-test data for the Resalat oil field located offshore southern Iran, the objective is to assist in the prediction and control of multi-phase flow rates of oil and gas through the wellhead chokes. For this purpose, 182 test data points (Appendix 1) related to the Resalat field are evaluated. In order to predict production flow rate (Q_L) expressed as stock-tank barrels per day (STB/D), this dataset includes four selected input variables: upstream pressure (Pwh); wellhead choke sizes (D64); gas to liquid ratio (GLR); and, base solids and water including some water-soluble oil emulsion (BS&W). The test data points evaluated include a wide range of oil flow rate conditions and values for the four input variables recorded. The TSFIS algorithm applied involves five data processing steps: a) pre-processing, b) fuzzification, c) rules base and adaptive neuro-fuzzy inference engine, d) defuzzification, and e) post-processing of the fuzzy model. The developed TSFIS model for the Resalat oil field database predicted oil flow rate to a high degree of accuracy (root mean square error = 247 STB/D, correlation coefficient = 0.9987), which improves substantially on the commonly used empirical algorithms used for such predictions. TSFIS can potentially be applied in wellhead choke fuzzy controllers to stabilize flow in specific wells based on real-time input data records.     

Combined constant speed control method for a wind generator equipped with hydraulic energy storage

A wind generator equipped with hydraulic energy storage (WG‐HES) uses hydraulic transmission systems instead of gearbox transmissions, thus eliminating high‐power converters and reducing the tower‐top cabin weight. When there is no wind or the wind speed is extremely low, the pressured oil released by accumulators is used to drive a motor to operate at a constant speed, thereby generating constant‐frequency power. However, few studies have examined the constant speed control characteristics for generating electricity using only an accumulator group. In this study, a combined constant speed (CCS) proportional–integral–derivative (PID) control method based on “variable displacement and throttling” is proposed, which includes two closed loops and one regulating loop. First, a simulation model of the CCS PID control method for a variable motor was established in the Simcenter Amesim program. The influence of different PID parameters on the anti‐interference ability of the constant speed control of the motor was analyzed under a given load step. Then, we obtained the range of control parameter values and a set of optimal values. Second, the effectiveness of the CCS control method and the accuracy of the simulation results were verified on a 600‐kW WG‐HES system prototype. The results verified that the CCS control method has good anti‐interference ability and can meet the requirements of constant speed control for a variable motor under the best PID parameters. These results can provide a basis for developing control strategies for WG‐HESs when there is no wind or at low wind speeds.