OPTIMUM CONTROL ON MINING RATE OF MINERAL RESOURCES

Several model are built to search optimum mining rate by rising optimum control theory Sor various purpose, A numerical method is extracted to assist both planer and decision maker of mining in their planing or scheduling work.

OPTIMUM CONTROL OF VIBRATION AND STRUCTURE－BORNE NOISE FOR MACHINERY ON FLEXIBLE FOUNDATION

Faced with the key problems of machinerv- induced vibration and structure-borne noise when dynamic machines are mounted on flexible foundations such as upper floors of facto- ry buildings, the vibration and noise transmission mechanism and optimal control for the flexible system are systematically studied by the novel approach of power flow. A more general system of machinery-isolators一flexible foundation is modelled. Based on substructure transfer matrix tech- nique the power flow input and transmitted are formulated in closed forms, and the effects that the flexibility of foundation and the asymmetricity of system have upon the power flow transmis- sion spectra are revealed, Also the inverse problems of isolation design are discussed by using an optimum method. Optimum design for a typical example about a force fan mounted on a con- crete building floor is successfully performed to show that the model is practical, the theory and the optimisation developed are reasonable and effective. Thereby, theoretical bases for accurate prediction of isolation effectiveness and an optimum method for practical design of a general flexi- ble isolation system are provided.

Optimum geometry of tuned liquid column-gas damper for control of offshore jacket platform vibrations under seismic excitation

In this study, the effectiveness of a tuned liquid column-gas damper, TLCGD, on the.suppression of seismic-induced vibrations of steel jacket platforms is evaluated. TLCGD is an interesting choice in the case of jacket platforms because it is possible to use the structural elements as the horizontal column of the TLCGD. The objective here is to find the optimum geometric parameters, namely orientation and configuration of vertical columns, length ratio, and area ratio of the TLCGD, considering nonlinear damping of the TLCGD and water-structure interaction between the jacket platform and sea water. The effects of different characteristics of ground motion such as PGA and frequency content on the optimum geometry are also investigated and it is observed that these features have some influence on the optimum area ratio. Finally it is observed that pulse arrangement of ground acceleration is one of the most important parameters affecting the efficiency of a TLCGD. In other words, it is found that the TLCGD＇s capability to reduce the RMS responses depends only on the frequency content of the ground acceleration, but its capability to reduce the maximum responses depends on both the frequency content and the pulse arrangement of the ground acceleration.

基于疫苗接种的SEIHRVI传染病模型分析与最优控制

为研究疫苗接种对控制传染病的影响,建立了具有标准发生率的传染病模型。通过推导得出模型的基本再生数,给出地方病平衡点的存在条件。借助构造Lyapunov函数证明了平衡点的全局稳定性。应用Pontryagin最大值原理分析了最优控制问题,得出最优控制策略。结果表明:提高疫苗接种率和效力能有效控制疾病传播;注意自我保护,及时接种以及重视治疗一定程度上可减小疾病爆发的规模。

植物不同生长期成分含量变化研究

综述了植物不同生长期多酚、多糖、氨基酸和蛋白质、萜类和挥发性成分含量变化的研究现状,为药材质量评价、确定最佳采收期、合理施肥、果蔬质量控制、副产物的合理开发利用等提供理论依据。

混合基础隔震体系优化设计及性能

为解决基础隔震结构中隔震层位移需求过大的问题,提出了一种基础隔震结构(Base Isolated Structure,BIS)+串并联调谐质量阻尼器惯容器(Tuned Tandem Mass Damper-Inerter, TTMDI)的混合隔震体系。采用Bouc-Wen滞回模型模拟隔震层的非线性力-变形行为,基于随机等效线性化和模式搜索优化算法并考虑地震动模型,在频域内建立了BIS+TTMDI体系的优化设计框架。分别从鲁棒性、有效性、刚度和阻尼系数、冲程及对地震频率敏感性方面对BIS+TTMDI体系的性能进行评估,并与BIS+调谐质量阻尼器(Tuned Mass Damper, TMD)、串并联调谐质量阻尼器(TunedTandemMassDamper,TTMD)和调谐质量阻尼器惯容器(TunedMass Damper-Inerter, TMDI)进行比较。通过对近场地震动下某七层混合基础隔震结构(包括BIS+TTMDI和BIS+TMDI体系)的动力弹塑性分析,评价了其减/隔震性能。结果表明:BIS+TTMDI体系具有最好的减/隔震性能和强鲁棒性;而且在BIS+TTMDI体系中TTMDI的总阻尼需求不到BIS+TMDI体系中TMDI的一半,因而更为经济实用。

考虑时频域性能指标的高超声速智能控制方法

针对高超声速飞行器在宽飞行包线、强气动不确定性条件下的姿态控制问题,提出了一种考虑系统时频域性能指标的智能最优控制方法。该方法分为离线与在线两部分:离线过程中,根据高超声速飞行器动力学模型与线性二次调节器(LQR)控制设计方法,生成大量姿态控制仿真样本数据集,构建控制性能指标评价模型,筛选最优控制参数,建立以飞行状态与气动不确定性为输入,最优LQR控制参数为输出的神经网络映射关系;在线过程中,通过实时气动参数辨识,捕获高超声速飞行器气动不确定性,运用智能参数优化网络,使得在气动不确定性条件下,高超声速飞行器姿态控制仍为满足控制指标的最优控制参数。最后,通过仿真验证了本文提出的方法能够有效提高宽飞行包线、强不确定性情况下高超声速飞行器姿态控制的鲁棒性。

STATISTIC LINEARIZATION CONTROL FOR HYDRAULIC ACTIVE DAMPING SUSPENSION

A statistic linearization analysis method of bad nolinear hydraulic active damping suspension is provided.Also the optimum control strategy of semi active suspension and graded control strategy based on it are puted forward.Experimental researches are carried out on a 2 DOF(degree of freedom) hydraulic active damping suspension test system.The results showed that an excellent control effectiveness could be obtained by using statistic linearization optimum control which unfortunely requests continuously regulationg the damp in an accurate way and costs much in engeering application.On the contrary,the results also showed that graded control is more practicable which has a control effectiveness close to the optimum control and costs less.

Multiparameter Optimization and Controlling for Cylindrical Grinding Process

This paper bursts the bondage of conventional no-burn thought, presents an optimum strategy permitting burn appear in grinding roughing stage, but the burning layer can be summed on the following finishing stage. On the base of the basic grinding models, the objective function and constrained functions for the multiparameter optimum grinding models had been built in this paper. By the computer simulation, the nonlinear optimum grinding control parameters had been obtained, and the truth grinding process had been controlled by these parameters. The results of simulation and the experiments proved the exactitude of the optimum models and the feasibility of the optimum strategy. This paper had also created the precondition for the grinding automation, virtual grinding and intelligent grinding system for cylindrical grinding process.

Distributed energy storage node controller and control strategy based on energy storage cloud platform architecture

Based on the energy storage cloud platform architecture,this study considers the extensive configuration of energy storage devices and the future large-scale application of electric vehicles at the customer side to build a new mode of smart power consumption with a flexible interaction,smooth the peak/valley difference of the load side power,and improve energy efficiency.A plug and play device for customer-side energy storage and an internet-based energy storage cloud platform are developed herein to build a new intelligent power consumption mode with a flexible interaction suitable for ordinary customers.Based on the load perception of the power grid,this study aims to investigate the operating state and service life of distributed energy storage devices.By selecting an integrated optimal control scheme,this study designs a kind of energy optimization and deployment strategy for stratified partition to reduce the operating cost of the energy storage device on the client side.The effectiveness of the system and the control strategy is verified through the Suzhou client-side distributed energy storage demonstration project.

考虑SSI效应时TMD的减震优化设计

土-结构相互作用(SSI)效应可能会对地震作用下调谐质量阻尼器(TMD)的有效性产生重要影响,因此本文研究了考虑SSI效应时TMD对高层建筑的抗震控制性能。针对一个质量分布均匀、层刚度随高度呈线性分布的40层benchmark结构,以结构顶层均方根位移最小为优化目标,采用改进粒子群算法对其在不同地基土条件以及地震波激励下的调谐质量阻尼器参数进行优化设计。优化结果表明,忽略SSI效应可能会造成地震激励下高层结构中TMD减震性能的不恰当估计,TMD的优化参数与地基土类型和地震波种类紧密相关。优化后的TMD可以有效降低结构顶层位移响应且不增加其峰值加速度,优化后的TMD耗散了绝大部分地震输入能量,并大大降低了结构能量。

热连轧板形控制的优化

为进一步提升热连轧机板形控制效果,满足理想板形的生产需求,在综合分析影响热连轧钢材板形控制因素的基础上,提出从算法和策略层面对板形控制等方面进行优化的总体思路,设计了板形凸度、平直度的二次反馈控制框图和基于最优控制算法的体系控制系统,并通过仿真验证了板形控制优化的效果。

混合策略的沙猫算法求解化工动态优化问题

化工动态优化问题的求解是实现化工过程自动控制的基础,对环保与经济效益方面均有理论和实际意义。提出一种ISCSO(混合策略的沙猫优化算法)来达到反应器高效优化的目的。首先,针对SCSO(沙猫算法)种群初始化缺乏多样性、容易聚集的问题,引入Circle混沌映射初始化种群,提高多样性。其次,针对沙猫算法在迭代后期收敛速度较慢、容易陷入局部最优的问题,引入随机游走策略。同时,采用柯西变异策略扰动全局最优解,生成新解,避免陷入局部最优,增强局部搜索能力。最后将其应用于3个具有挑战性的化学动态优化工程问题上,并与其他方法进行对比分析。结果表明,改进后的算法具有更强的寻优和求解能力,证明了其有效性和优越性。

基于遗传算法的无人机最优控制器设计

无人机纵向通道最优控制器设计中,状态变量加权矩阵Q和控制变量加权矩阵R直接影响控制系统的性能,Q阵中元素选取直接影响其对应的状态变量性能,R阵中的元素影响其对应的控制变量能量消耗。以升降舵控制输入值、迎角的输出峰值和超调量的加权为适应度函数,应用遗传算法对Q和R中的元素进行寻优,从而提高设计效率。

基于深度强化学习的同步发电机最优励磁控制方法

常规的同步发电机最优励磁控制方法主要使用ARX(AutoRegressive with eXternal input)自回归各态经历模型生成控制传递函数,易受采样周期离散化作用影响,导致控制扰动过高,因此提出基于深度强化学习设计一种全新的同步发电机最优励磁控制方法。构建了同步发电机最优励磁控制模型,利用深度强化学习设计了同步发电机励磁模糊控制器,优化了同步发电机最优励磁控制参数,从而实现了同步发电机最优励磁控制。实验结果表明,同步发电机深度强化学习最优励磁控制方法在不同状态下的控制扰动均较低,说明控制效果较好,具有可靠性,有一定的应用价值。

不平衡工况下的蓄热式燃气加热炉最佳炉温复合控制技术

为了使蓄热式燃气加热炉可以在不平衡工况下实现更稳定、精准的温度控制,提高产品质量和生产效率,提出不平衡工况下的蓄热式燃气加热炉最佳炉温复合控制技术。分析蓄热式燃气加热炉的运行方式以及运行过程中的能量守恒定律,对蓄热式燃气加热炉进行机理建模;以此为基础,通过温度传感器实时反馈蓄热式燃气加热炉的炉温信息,将监测的温度数据传递给结合模糊控制和PID控制的模糊PID复合控制器,模糊PID复合控制器接收到炉温的监测结果后,与设定的加热炉温度进行对比,运算监测温度与设定温度之间的差,并计算差异的变化速度,将得到的结果模糊化后,依据模糊规则表,不断地调节模糊PID整定参数,得出控制量,将其作为参考值,用于调节空气阀和燃气阀,实现蓄热式燃气加热炉最佳炉温复合控制。实验结果表明:该技术能够在15s内稳定地控制蓄热式燃气加热炉的炉温,具有较小的超调量;可有效地提高蓄热式燃气加热炉坯料头、中、尾部的温度均匀性,保证产品质量的同时提高了蓄热式燃气加热炉的小时产量,降低生产能耗和成本。

Bending analysis and control of rolled plate during snake hot rolling

In order to study the bending behavior of aluminum alloy 7050 thick plate during snake hot rolling, several coupled thermo-mechanical finite element(FE) models were established. Effects of different initial thicknesses, pass reductions, speed ratios and offset distances on the bending value of the plate were analyzed. ‘Quasi smooth plate' and optimum offset distance were defined and quasi smooth plate could be acquired by adjusting offset distance, and then bending control equation was fitted. The results show that bending value of the plate as well as the extent of the increase grows with the increase of pass reduction and decrease of initial thickness; the bending value firstly increases and then keeps steady with the ascending speed ratio; the bending value can be reduced by enlarging the offset distance. The optimum offset distance varies for different rolling parameters and it is augmented with the increase of pass reduction and speed ratio and the decrease of initial thickness. A proper offset distance for different rolling parameters can be calculated by the bending control equation and this equation can be a guidance to acquire a quasi smooth plate. The FEM results agree well with experimental results.

A Study on the Stability Analysis and Optimum Design for Journal Bearings

Based on the establishment of a differential equation of motion and the solution of the oil film whirling locus of the Journal center, a method of judging the stability of bearing is presented. Meanwhile a method of bearing parameter optimization for the optimal stability is recommended. Finally, a short journal bearing is given as an example to illustrate the reasonableness and feasibility of the method.

Optimal Robust Control for Unstable Delay System

Proportional-Integral-Derivative control system has been widely used in industrial applications.For uncertain and unstable systems,tuning controller parameters to satisfy the process requirements is very challenging.In general,the whole system’s performance strongly depends on the controller’s efficiency and hence the tuning process plays a key role in the system’s response.This paper presents a robust optimal Proportional-Integral-Derivative controller design methodology for the control of unstable delay system with parametric uncertainty using a combination of Kharitonov theorem and genetic algorithm optimization based approaches.In this study,the Generalized Kharitonov Theorem(GKT)for quasi-polynomials is employed for the purpose of designing a robust controller that can simultaneously stabilize a given unstable second-order interval plant family with time delay.Using a constructive procedure based on the Hermite-Biehler theorem,we obtain all the Proportional-Integral-Derivative gains that stabilize the uncertain and unstable second-order delay system.Genetic Algorithms(GAs)are utilized to optimize the three parameters of the PID controllers and the three parameters of the system which provide the best control that makes the system robust stable under uncertainties.Specifically,the method uses genetic algorithms to determine the optimum parameters by minimizing the integral of time-weighted absolute error ITAE,the Integral-Square-Error ISE,the integral of absolute error IAE and the integral of time-weighted Square-Error ITSE.The validity and relatively effortless application of presented theoretical concepts are demonstrated through a computation and simulation example.

Optimum placement and characteristics of velocity-dependent dampers under seismic excitation

In this study, through novel drift-based equations of motion in the frequency domain, optimum placement and characteristics of linear velocity-dependent dampers are investigated. In this study, the sum of the square of the absolute values of transfer matrix elements for interstory drifts is considered as the optimization index. Optimum placement and characteristics of dampers are simultaneously obtained by minimizing the optimization index through an incremental procedure. In each step of the procedure, a predefined value is considered as the damper characteristic. The optimum story for this increment is selected such that it leads to a minimum value for the optimization index. The procedure is repeated for the next increments until the optimization index meets its target value, which is obtained according to the desired damping ratio for the overall structure. In other words, the desired overall damping ratio is the input to the proposed procedure, and the optimal placement and characteristics of the dampers are its output. It is observed that the optimal placement of a velocitydependent damper depends on the damping coefficient of the added damper, frequency of the excitation, and distribution of the mass, stiffness, and inherent damping of the main structure.