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浙江大学学报(工学版)  2019, Vol. 53 Issue (5): 843-851    DOI: 10.3785/j.issn.1008-973X.2019.05.004
计算机与控制工程     
基于梯度信息的实时优化与控制集成策略
李啸晨(),苏宏业*(),邵寒山,谢磊
浙江大学 智能系统与控制研究所,浙江 杭州 310027
Gradient information-based strategy for real time optimization and control integration
Xiao-chen LI(),Hong-ye SU*(),Han-shan SHAO,Lei XIE
Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou 310027, China
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摘要:

针对工业过程的最优操作问题,分析过程系统的层次模型,提出实时优化与控制集成的级联结构. 对于优化层采用基于梯度信息的稳态实时优化方法,通过在线采集过程测量值,估计过程的梯度信息,更新设定值. 不需要使用显式的过程模型,可以有效抑制模型失配对优化目标的影响. 利用最小二乘的思想求解梯度向量,降低计算成本,可应用于大规模工业过程的稳态实时优化. 提出非线性过程中被控变量的选取方法,利用非线性模型计算平均损失,优化效果具有全局性. 为了快速求解非线性规划问题,对某些条件进行合理假设,从而获得次优解,给出求解被控变量的解析方法,提高计算效率,同时将优化层与控制层联系起来. 通过对数值算例、蒸发过程和放热反应过程的研究,验证所提出方法的有效性.

关键词: 最优操作层次模型级联结构梯度信息最小二乘被控变量    
Abstract:

The hierarchy model of process system was analyzed, and the cascade structure of real time optimization and control integration was proposed, aiming at the optimal operation problem for industrial process. Gradient information-based steady state real time optimization approach was installed in the optimization layer. The setpoint was updated by collecting measurements online and estimating the gradient information of process. The proposed approach can effectively suppress the impact of plant model mismatch on optimization objective, since it avoided using an explicit process model. A least square thought was introduced to compute the gradient vector. The proposed algorithm not only had a low computational burden, but also can be applied to the steady state real time optimization of large-scale industrial processes. A method for selecting controlled variables of nonlinear process was discussed. The proposed method minimized the global average loss based on the nonlinear model. Reasonable assumptions were made for some conditions, so that the suboptimal solution was obtained, in order to solve the nonlinear programming problem efficiently. The analytical solution of controlled variables was given and the calculation efficiency was improved as well as the optimization layer was connected with the control layer. A numerical example, evaporation process and exothermic reaction process were studied to illustrate the effectiveness of the proposed method.

Key words: optimal operation    hierarchy model    cascade structure    gradient information    least square    controlled variables
收稿日期: 2018-03-30 出版日期: 2019-05-17
CLC:  TP 273  
通讯作者: 苏宏业     E-mail: lixiaochen@zju.edu.cn;hysu@iipc.zju.edu.cn
作者简介: 李啸晨(1992—),男,博士生,从事工业过程先进控制与优化技术研究. orcid.org/0000-0003-0826-2868. E-mail: lixiaochen@zju.edu.cn
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引用本文:

李啸晨,苏宏业,邵寒山,谢磊. 基于梯度信息的实时优化与控制集成策略[J]. 浙江大学学报(工学版), 2019, 53(5): 843-851.

Xiao-chen LI,Hong-ye SU,Han-shan SHAO,Lei XIE. Gradient information-based strategy for real time optimization and control integration. Journal of ZheJiang University (Engineering Science), 2019, 53(5): 843-851.

链接本文:

http://www.zjujournals.com/eng/CN/10.3785/j.issn.1008-973X.2019.05.004        http://www.zjujournals.com/eng/CN/Y2019/V53/I5/843

图 1  一般过程系统的层级模型
图 2  实时优化与控制集成的级联结构
图 3  本研究所提出方法与文献[26]所提出方法的性能损失对比
图 4  蒸发过程反应原理图
变量名称 物理含义 标称值 单位
qm1 进料质量流量 9.469 kg/min
qm2 产物质量流量 1.334 kg/min
qm3 循环质量流量 24.721 kg/min
qm4 气相质量流量 8.135 kg/min
qm5 冷凝液质量流量 8.135 kg/min
x1 进料摩尔分数 5.0% ?
x2 产物摩尔分数 35.0% ?
1 进料温度 40.000 °C
2 产物温度 88.400 °C
3 气相温度 81.066 °C
L2 分离器液位 1.000 m
p2 操作压力 51.412 kPa
qm100 蒸汽质量流量 9.434 kg/min
100 蒸汽温度 151.520 °C
p100 蒸汽压力 400.000 kPa
Q100 热负荷 345.292 kW
qm200 冷却水质量流量 217.738 kg/min
200 冷却水入口温度 25.000 °C
201 冷却水出口温度 45.550 °C
Q200 冷却器热负荷 313.210 kW
表 1  蒸发过程中变量的物理含义和标称值
测量子集 本研究方法 文献[26]方法
Lav Lmax t/s Lav Lmax t/s
y1 4.33 34.28 0.185 9.92 56.72 0.412
y2 0.37 5.08 0.354 0.53 7.86 1.271
y3 0.28 3.93 0.783 0.46 6.24 3.464
y4 0.42 6.65 1.371 0.61 9.93 7.323
表 2  本研究方法与文献[26]方法的计算效果对比
图 5  连续搅拌釜式反应器反应原理图
变量名称 标称值 单位
coA 0.498 mol/L
coB 0.502 mol/L
To 426.803 K
ciA 1 mol/L
ciB 0 mol/L
Ti 424.292 K
τ 60 s
表 3  CSTR模型中变量的标称值
图 6  扰动变量的变化轨迹
图 7  文献[28]方法得到的测量变量的变化轨迹
图 8  本研究方法得到的测量变量的变化轨迹
图 9  本研究方法与文献[28]方法得到的操纵变量对比
图 10  本研究方法与文献[29]方法得到的目标函数对比
1 VARMA V A, REKLAITIS G V, BLAU G E, et al Enterprise-wide modeling and optimization: an overview of emerging research challenges and opportunities[J]. Computers and Chemical Engineering, 2007, 31 (5/6): 692- 711
2 SHOKRI S, HAYATI R, MARVAST M A, et al Real time optimization as a tool for increasing petroleum refineries profits[J]. Petroleum and Coal, 2009, 51 (2): 110- 114
3 ZHANG Y, MONDER D, FORBES J F Real-time optimization under parametric uncertainty: a probability constrained approach[J]. Journal of Process Control, 2017, 12 (3): 373- 389
4 BRDYS M A, TATJEWSKI P. Iterative algorithms for multilayer optimizing control [M]. London: Imperial College Press, 2005: 128–144.
5 ROBERTS P D An algorithm for steady-state system optimization and parameter estimation[J]. International Journal of Systems Science, 1979, 10 (7): 719- 734
doi: 10.1080/00207727908941614
6 TATJEWSKI P Iterative optimizing set-point control: the basic principle redesigned[J]. IFAC Proceedings Volumes, 2002, 35 (1): 49- 54
7 GAO W, ENGELL S Iterative set-point optimization of batch chromatography[J]. Computers and Chemical Engineering, 2005, 29 (6): 1401- 1409
doi: 10.1016/j.compchemeng.2005.02.035
8 YE L, CAO Y, YUAN X, et al. Retrofit self-optimizing control of Tennessee Eastman process [C] // IEEE International Conference on Industrial Technology. Piscataway: IEEE, 2016: 866–871.
9 BINETTE J C, SRINIVASAN B, BONVIN D On the various local solutions to a two-input dynamic optimization problem[J]. Computers and Chemical Engineering, 2016, 95: 71- 74
doi: 10.1016/j.compchemeng.2016.09.003
10 SKOGESTAD S Plantwide control: the search for the self-optimizing control structure[J]. Journal of Process Control, 2000, 10 (5): 487- 507
doi: 10.1016/S0959-1524(00)00023-8
11 GE X, ZHU Y A necessary condition of optimality for uncertain optimal control problem[J]. Fuzzy Optimization and Decision Making, 2013, 12 (1): 41- 51
doi: 10.1007/s10700-012-9147-4
12 VERHEYLEWEGHEN A, J?SCHKE J Self-optimizing control of a two-stage refrigeration cycle[J]. IFAC PapersOnLine, 2016, 49 (7): 845- 850
doi: 10.1016/j.ifacol.2016.07.295
13 ARAúJO A C B D, GOVATSMARK M, SKOGESTAD S Application of plantwide control to the HDA process: I. steady-state optimization and self-optimizing control[J]. Control Engineering Practice, 2007, 15 (10): 1222- 1237
doi: 10.1016/j.conengprac.2006.10.014
14 SKOGESTAD S Selection of controlled variables and robust setpoints[J]. Industrial and Engineering Chemistry Research, 2002, 35 (1): 351- 356
15 HALVORSEN I J, SKOGESTAD S, MORUD J C, et al Optimal selection of controlled variables[J]. Industrial and Engineering Chemistry Research, 2003, 42 (14): 3273- 3284
doi: 10.1021/ie020833t
16 YE L, CAO Y, SKOGESTAD S Global self-optimizing control for uncertain constrained process systems[J]. IFAC PapersOnLine, 2017, 50 (1): 4672- 4677
doi: 10.1016/j.ifacol.2017.08.691
17 SRINIVASAN B, PRIMUS C J, BONVIN D, et al Run-to-run optimization via control of generalized constraints[J]. Control Engineering Practice, 2001, 9 (8): 911- 919
doi: 10.1016/S0967-0661(01)00051-X
18 SRINIVASAN B, BONVIN D, VISSER E, et al Dynamic optimization of batch processes: II. role of measurements in handling uncertainty[J]. Computers and Chemical Engineering, 2003, 27 (1): 27- 44
doi: 10.1016/S0098-1354(02)00117-5
19 ALSTAD V, SKOGESTAD S, HORIA E S Optimal measurement combinations as controlled variables[J]. Journal of Process Control, 2009, 19 (1): 138- 148
doi: 10.1016/j.jprocont.2008.01.002
20 XIN S, GUO Q, SUN H, et al Cyber-physical modeling and cyber-contingency assessment of hierarchical control systems[J]. IEEE Transactions on Smart Grid, 2017, 6 (5): 2375- 2385
21 SKOGESTAD S Control structure design for complete chemical plants[J]. Computers and Chemical Engineering, 2004, 28 (1/2): 219- 234
22 KEADTIPOD P, BANJERDPONGCHAI D. Design of supervisory cascade model predictive control for industrial boilers [C]// Automatic Control Conference. Piscataway: IEEE, 2017: 122–125.
23 DARBY M L, NIKOLAOU M, JONES J, et al RTO: an overview and assessment of current practice[J]. Journal of Process Control, 2011, 21 (6): 874- 884
doi: 10.1016/j.jprocont.2011.03.009
24 KNAPP R, HU Y. Numerical optimization [M]// Berlin: Springer, 2018: 29–76.
25 BEBIANO N. Applied and computational matrix analysis [M]. Berlin: Springer, 2017: 58.
26 ALSTAD V, SKOGESTAD S Null space method for selecting optimal measurement combinations as controlled variables[J]. Industrial and Engineering Chemistry Research, 2007, 46 (3): 846- 853
doi: 10.1021/ie060285+
27 KARIWALA V, CAO Y, JANARDHANAN S Local self-optimizing control with average loss minimization[J]. Industrial and Engineering Chemistry Research, 2008, 47 (4): 1150- 1158
doi: 10.1021/ie070897+
28 FRAN?OIS G, SRINIVASAN B, BONVIN D Use of measurements for enforcing the necessary conditions of optimality in the presence of constraints and uncertainty[J]. Journal of Process Control, 2005, 15 (6): 701- 712
doi: 10.1016/j.jprocont.2004.11.006
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