Parameter Optimization And Performance Assessment Based On Combined Integrating Control System

In the process industries,such as tobacco,petroleum,chemical engineering,etc.,there is a wide range of combined integrating processes that are composed of multiple integral time-delay process.At present,these processes are often approximated as low-order plus dead time processes and controlled by common control algorithms.Although these processes can meet the fundamental production requirements,it also makes it difficult to further improve the control performance.At present,according to the structural characteristics of several different structures,the existing scholars have proposed a corresponding integrated controller to achieve a good performance in the actual industrial process.In actual industrial control loops,the parameters of the controller may change due to change of the equipment and operating environment,that leads to controller mismatch and instability.Therefore,it is very necessary to propose and formulate a set of relatively perfect controller performance evaluation criteria and optimization strategies for the combined-integrating controller.For the evaluation of controller performance and optimization strategies,many scholars have proposed some programs and successfully applied in the actual industrial process,which ensured the stable operation of the entire control system and brought direct economic benefits to the production companies.In this paper,In this paper,a strategy is proposed,which contains a parameter estimation strategy,an absolute error integral performance index criterion,and a robustness index criterion for the combined-integrating process.Combining these three strategies together,a solution including parameter estimation,controller design,controller performance monitoring,and controller optimization was developed for the combined integral control system.The main work and innovations of this paper are included in the following several aspects:(1)Combining the definition of the combined score system and its structural features.A combination of integral control algorithm was proposed and verified by simulation.The good control performance was verified.Its good open-loop characteristics are extended to the general low-order time-delay process,and a pseudo-prediction PI/PID controller is designed.(2)Combining the least squares parameter estimation method with the combined integrating characteristics.And the effectiveness was verified by simulation experiments.(3)Analyze and introduce the absolute error performance index and robust performance index.Analyze the absolute error performance index and define the criteria for the first-order and second-order time-delay combination-integration process.Also,it is robust to the combined integrating controller.The relationship between the sex index and the definition of the criterion was carried out.The dimensionless simulation curve was used to verify the trend of the tunable parameters and robustness of the combinatorial integral controller.(4)Combined the combined-integrating process parameters identification strategy,Integral absolute error performance indicators and robust performance indicators.And propose the performance evaluation and optimization strategy of the combined-integrating control system.And take the actual one-order combined-integrating process and two-order combined-integrating process as examples.Use the strategy proposed above to perform simulation experiments in Matlab/Simulink.It is verified that this strategy can make the combined-integrating controller can achieve the best control performance under the premise of taking into account the multiple performance indexes of the combined-integrating control system.