关键词： 经济模型预测控制(EMPC)   约束非线性系统   安全控制   稳定性  

摘要： 考虑输入仿射非线性约束系统的安全与经济优化控制问题,提出一种约束非线性系统高效安全经济模型预测控制(SEMPC)策略。首先引入控制李雅普诺夫障碍函数(CLBF)概念,设计系统运行安全约束和参数化非线性局部控制律。为平衡SEMPC的在线计算量和经济优化性能,构造约束非线性系统的参数化双模模型预测控制(MPC)控制器,其中,控制器自由参数在系统状态进入终端域后在线优化确定。进一步,应用双模控制原理和控制李雅普诺夫函数性质,证明SEMPC策略的递推可行性和闭环系统的渐近稳定性。最后,通过对一连续搅拌釜反应器的安全、经济和稳定控制的仿真实验,验证了本文策略的有效性。

关键词： Braking   Roads   Fuels   Optimization   Trucks   Vehicles   Fuel consumption   Traffic   Highways   Trajectories (Physics)   Fuel efficiency   Control equipment   Dynamic models   Predictive control  

摘要： This paper introduces a hierarchical economic model predictive control (MPC) approach for maximizing the fuel economy of a heavy-duty truck, which simultaneously accounts for aggregate terrain changes that occur over very long length scales, fine terrain changes that occur over shorter length scales, and lead vehicle behavior that can vary over much shorter time/length scales. To accommodate such disparate time and length scales, the proposed approach uses a multilayer MPC approach wherein the upper-level MPC uses a long distance step, a long time-step, and coarse discretization to account for the slower changes in road grade, while the lower-level MPC uses a shorter time-step to account for fine variations in road grade and rapidly changing lead vehicle behavior. The benefit of this multirate, multiscale approach is that the lower-level MPC leverages the upper-level's sufficiently long look-ahead while allowing for safe vehicle following and adjustment to fine road grade variations. The proposed strategy has been evaluated over four real-world road profiles in both open-highway and traffic environments, using a medium-fidelity simulink model furnished by Volvo Group North America. Compared with a conventional cruise control system plus vehicle following controller as a baseline, results show 4-5% fuel savings in an open highway setting and 6-8% fuel savings in the presence of traffic, without compromising trip time.

关键词： 微观经济学   经济模型   宏观经济学   非经济学专业   尝试运用   诸多问题   兴趣  

摘要： 我们一直在尝试运用经济学破解现实世界中存在的诸多问题。高深与艰涩并不是经济学的本意,对于非经济学专业的读者而言,动辄经济模型与深奥推论让他们对经济学提不起太多兴趣,但是,无论是宏观经济学还是微观经济学,其本质都在于解决现实问题,只不过二者研究的重点不同而已。

关键词： Model predictive control  

摘要： In this paper, it is shown that a simple formulation of Economic Model Predictive Control can be used which possesses two features that are generally viewed as mutually exclusive, namely, a rather short prediction horizon (reachability-compatible) on one side, and the absence of final constraint on the other side. Practical stability at an arbitrarily small neighborhood of the optimal unknown steady-state pair is shown when some design parameters increase. It is also shown that when the system is originated from the time discretization of a continuous-time dynamics, the size of the terminal region can be reduced by decreasing the sampling period for the same design parameter setting. A commonly used example is given to illustrate the results. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Process design   Parenterals   Lot resizing   Decision-making   Mathematical model   Optimization  

摘要： Purpose Choosing the optimal lot size in drug manufacturing has critical implications for process scheduling and economic performance. There are no rigorous models addressing drug product manufacturing. This work offers a lot-sizing model to avoid empirical decisions for lot resizing at various drug lifecycle phases or for grassroot design of injectable drug product manufacturing. Methods An economic lot-sizing model for manufacturing injectables that included process-specific risks and aspects such as rates of defective products, quality control, and changeover operations was developed. Change-control costs for revalidation required by regulatory authorities in case of lot resizing were also considered. A sensitivity analysis was carried out to determine influential model parameters. Results Two case studies representing different drug profiles demonstrated the use of the method: (i) an inexpensive injectable filled in an ampule after patent expiry;(ii) a new, expensive injectable product filled in vials. Depending on the drug profile, the controlling factors were found to be different, e.g., overtime production scheduling in case (i) and defective product rates in case (ii). Conclusion This work highlighted the usefulness of model-based approaches for determining influential parameters, design tradeoffs, and improvement potential. The approach was demonstrated for retrofit and grassroot design cases in pharmaceutical manufacturing.

关键词： Economic model predictive control   Robust economic model predictive control   Optimization   Storage networks   Supply chain management   Inventory control  

摘要： A tube-based robust economic model predictive control scheme is proposed for sparse, linear storage network systems under bounded disturbances. We present a modeling framework that reflects conservation principles, and for which a centralized controller optimizes a performance metric for the entire network over a finite time horizon. Our main result is a computationally efficient projection-based approach that exploits the sparse structure of the system dynamics for tightening state and input constraints, in the meantime ensuring that average performance, recursive feasibility, and asymptotic stability of the system are maintained. An inventory control problem under demand uncertainty is presented to illustrate the advantages of the proposed framework and benchmark against nominal economic model predictive control. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Optimisation techniques   Power system management, operation and economics   Distribution networks   Optimisation techniques   Optimal control  

摘要： Generally, the modern networked energy systems are constructed from some coupled sub-systems interconnected via their states and share their information through a communication network featuring time delays. This article suggests an efficient multi-agent based cooperative-distributed networked economic model predictive control scheme for energy consumption optimisation and reducing the cost of consumed electricity in network-based smart energy systems considering communication network delays. In this regard, a buffer-based moving horizon strategy with estimator is suggested to estimate the own states of every sub-system and the coupled states, that is, the states in which their information exchange among sub-systems and their values are not accessible due to communication time delays. Moreover, the boundedness of the estimation error as well as the stability of the closed-loop system are established. The usability and proficiency of the suggested scheme are proved by applying the developed approach on two case studies.

关键词： Benchmark simulation model no. 2   Dosing control   Economic MPC   Struvite production   Water resource recovery  

摘要： Resource recovery from municipal wastewater has been a prime focus for a decade. Although several recovery processes already exist in the market today, the high cost of material, inherent disturbance in the influent quality, lack of real time monitoring of critical parameters, and lack of a robust automation system may result in suboptimal performance. This work attempts to construct a model based predictive control for optimal operation of a struvite recovery unit in a full scale WRRF. A multi-parameter based predictive control has been developed by implementing an Economic Model Predictive Controller (EMPC) for optimal dosing of magnesium hydroxide in a struvite recovery unit. The EMPC used customized objective function for real-time optimization of performance and economical parameters of the crystallization unit. The effectiveness of the proposed EMPC controller is verified through tests conducted on the Benchmark Simulation Model No. 2 (BSM2d.). The results obtained from the simulator-based evaluation of EMPC demonstrate a significant improvement in resource recovery at reduced operational costs. The economic advantages of implementing an EMPC compared to proportional and constant magnesium dosage has also been enumerated.

关键词： Circular economy   Cleaner production   Environmental management   Recycling   Resource efficiency   Business model  

摘要： Farmutil is one of the largest and most modern agro-food consortia operating in the Polish market, and has developed a sustainable development strategy for over four decades. The management system implemented in Farmutil exemplifies the application of basic elements of the circular economy in industrial practice by using cleaner technologies. The production management model at Farmutil has the form of a system of connected stream flows of materials and energy. The solution includes the prevention of environmental pollution through the implementation of new technologies, the reduction and reuse of waste, recycling and the recovery of materials and energy, the substitution of raw materials with waste and the use of processed waste as biofuel. The model is a system covering the full lifecycle of products, from cereal cultivation through to the production of industrial feed and poultry and pig breeding for the production of meat products. The information gained from the theoretical and empirical parts of the study shows the possibility of their use to create a policy which allows the widespread implementation of circular economy activities, not only by eco-friendly technological innovation, cleaner production or eco-efficient solutions for production and waste minimisation, but also at the organisational and social levels. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： 大数据   数量经济学   BP神经网络   CPI  

摘要： 大数据时代的来临,掀起了大数据与传统学科融合发展的热潮,探寻"大数据+数量经济学模型"的发展之路势在必行。本文运用文献计量分析,对大数据时代较有代表性的定量研究方法和模型进行分类梳理,并基于BP神经网络模型结合36个指标数据对中国居民消费价格指数(CPI)进行多元变量预测。研究表明,BP神经网络的预测结果最优。因此,未来要强化传统数量经济学的大数据化升级,注重非线性、非参数、模型自由化的研究方法在实际问题中的应用。