scholarly journals Application of the Modified Fuzzy-PID-Smith Predictive Compensation Algorithm in a pH-Controlled Liquid Fertilizer System

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1506
Author(s):  
Yongchao Shan ◽  
Lixin Zhang ◽  
Xiao Ma ◽  
Xue Hu ◽  
Zhizheng Hu ◽  
...  
Keyword(s):  
Control System ◽  
Ph Value ◽  
Control Group ◽  
Fuzzy Pid ◽  
Flow Rates ◽  
Liquid Fertilizer ◽  
Modern Agriculture ◽  
Compensation Algorithm ◽  
Output Flow ◽  
Non Linear

An appropriate pH value of liquid fertilizer can enable crops to better absorb nutrients from fertilizers. However, the mixed liquid fertilizer with high concentration of liquid fertilizer and irrigation water has a high pH value, which affects the absorption of nutrients by crops. Therefore, the precise regulation of liquid fertilizer pH value is an important link to realize the integration of water and fertilizer in modern agriculture. Due to pipeline transportation and diffusion of the regulating liquid and liquid fertilizer, the pH value control system has the characteristics of time-varying, non-linear and time-delayed models, and it is difficult for ordinary controllers to accurately control the pH value of liquid fertilizer. Therefore, modern agriculture urgently needs a controller that can adapt to non-linear and uncertain systems. According to the characteristics of the pH regulation process of liquid fertilizer, this study proposes and designs a modified fuzzy-PID-Smith predictive compensation algorithm, which adds the fuzzy-PID algorithm to the predictor of the conventional Smith algorithm to compensate for the error between the actual and theoretical models in order to reduce the decline of control quality caused by the model mismatch to the control system. To verify the practicability and robustness of the algorithm in practical applications, a liquid fertilizer pH value control system with STM32F103ZET6 as the control core was developed. The pH control system with fuzzy-PID and Smith algorithm as controller was used as the control group. The model was simulated and tested under two conditions of exact matching and imprecise matching, and performance tests were carried out under different output flow rates. The results showed that the maximum overshoot of the modified fuzzy-PID-Smith predictive compensation algorithm was significantly less than that of the other two algorithms at different output flow rates, with an average of 0.23%. The average steady-state time of adjusting the pH value of liquid fertilizer from 7.3 to 6.8 was 72 s, which was superior to the 145 s and 3.2% of fuzzy-PID and 130 s and 1.4% of the Smith controller.

scholarly journals Research on pH Value Control System of Haematococcus Pluvialis Algae Based on Fuzzy PID Algorithm

2020 ◽  
Vol 1631 ◽  
pp. 012051
Author(s):  
Shigang Cui ◽  
Xingzong Cai ◽  
Yongli Zhang ◽  
Xingli Wu ◽  
Lin He
Keyword(s):  
Control System ◽  
Ph Value ◽  
Haematococcus Pluvialis ◽  
Fuzzy Pid ◽  
Pid Algorithm

Model Predictive Control of a pH Maintaining System

2013 ◽  
Vol 11 (1) ◽  
pp. 14-20
Author(s):  
A. Grancharova ◽  
L. Kostov
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Ph Value ◽  
Rate Of Change ◽  
Nonlinear Model Predictive Control ◽  
Box Constraints ◽  
Input Flow ◽  
Flow Rates ◽  
Optimal Regulation ◽  
Output Flow

Abstract In this paper the problem of optimal regulation of a pH maintaining system is considered, where the outputs are the pH value and the liquid level in the system and the control inputs are the flow rates of the base input flow and the output flow. The optimal regulation problem is formulated as a nonlinear model predictive control problem in the presence of constraints. Two cases are considered: 1) presence of box constraints only on the control inputs and 2) considering also constraints on the rate of change of the inputs.

Investigation of the stability of periodic motions in a nonlinear automatic control system based on the fast fourier transform

2003 ◽  
Vol 3 ◽  
pp. 297-307
Author(s):  
V.V. Denisov
Keyword(s):  
Fourier Transform ◽  
Control System ◽  
Automatic Control ◽  
Fast Fourier Transform ◽  
Automatic Control System ◽  
Resonance Phenomenon ◽  
Periodic Motions ◽  
Multiply Connected ◽  
Non Linear ◽  
The Stability

An approach to the study of the stability of non-linear multiply connected systems of automatic control by means of a fast Fourier transform and the resonance phenomenon is considered.

scholarly journals Design of self-heating test platform for sulfide corrosion and oxidation based on Fuzzy PID temperature control system

2021 ◽  
pp. 002029402110203
Author(s):  
Cheng-Wei Chu ◽  
Zhi-Chao Zhu ◽  
Hai-Tao Bian ◽  
Jun-Cheng Jiang
Keyword(s):  
Control System ◽  
Optical Fiber ◽  
Temperature Control ◽  
Optical Fiber Sensor ◽  
Oxidation Temperature ◽  
Fiber Sensor ◽  
Fuzzy Pid ◽  
Test Platform ◽  
Sulfide Corrosion ◽  
Corrosion And Oxidation

In this paper, the changes of oxidation temperature of sulfide corrosion and the deficiency of distributed optical fiber application were analyzed. The test platform of oxidation temperature of sulfide corrosion was established, and the performance test of optical fiber and the simulation of oxidation temperature of sulfide corrosion were realized. The hardware part of the control system used STM32 as the controller, the software part was based on the process characteristics of the controlled object, using MATLAB to carry out the simulation of PID, fuzzy, fuzzy PD plus I, fuzzy PID algorithms, and their performance are evaluated using both single indexes and comprehensive indexes. The experimental results also showed that the proposed fuzzy PID can achieve better control performance with less overshoot and shorter setting time. Therefore, the fuzzy PID was chosen as the temperature control algorithm to build the optical fiber sensor test platform, and an alarm method for testing the oxidation temperature of large area sulfide corrosion based on the optical fiber performance was obtained. Then, considering the influence of spatial resolution on optical fiber sensor, this paper used piecewise PID to simulate the temperature rise process of three stages of sulfurization corrosion and oxidation. The results showed that the alarm method of oxidation temperature of sulfurization corrosion has limitations for small-scale oxidation of sulfurization corrosion, and it needed to be combined with machine learning to identify temperature anomaly.

Intelligent Information of TS Fuzzy PID Control System of BLDCM

2013 ◽  
Vol 846-847 ◽  
pp. 313-316 ◽  
Author(s):  
Xiao Yun Zhang
Keyword(s):  
Control System ◽  
Dynamic Model ◽  
Pid Control ◽  
Control Method ◽  
Design Method ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Control Precision ◽  
Simulation Results ◽  
Intelligent Information

This paper presented a new method based on the Fuzzy self - adaptive PID for BLDCM. This method overcomes some defects of the traditional PID control. Such as lower control precision and worse anti - jamming performance. It dynamic model of BLDCM was built, and then design method for TS fuzzy PID model is given, At last, it compared simulation results of PID control method with TS Fuzzy PID control method. The results show that the TS Fuzzy PID control method has more excellent dynamic antistatic performances, as well as anti-jamming performance. The experiment shows that TS fuzzy PID control has the stronger adaptability robustness and transplant.

Simulation Analysis of Electro-Pneumatic Proportional Fuzzy-PID Control System Based on AMESim/Simulink

2014 ◽  
Vol 945-949 ◽  
pp. 2568-2572
Author(s):  
Si Yuan Wang ◽  
Guang Sheng Ren ◽  
Pan Nie
Keyword(s):  
Control System ◽  
Pid Control ◽  
Pid Controller ◽  
Simulation Analysis ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Proportional Control ◽  
Fuzzy Pid Controller ◽  
Design Requirements ◽  
Set Up

The test rig for hydro-pneumatic converter used in straddle type monorail vehicles was researched, and its electro-pneumatic proportional control system was set up and simulated based on AMESim/Simulink. Compared fuzzy-PID (Proportion Integral Derivative) controller with PID controller through fuzzy logic tool box in Simulink, the results indicate that, this electro-pneumatic proportional control system can meet design requirements better, and fuzzy-PID controller has higher accuracy and stability than PID controller.

The Application of Adaptive Fuzzy PID in the Liquid Level Cascade Control System

2013 ◽  
Vol 846-847 ◽  
pp. 321-324 ◽  
Author(s):  
Le Peng Song ◽  
Hua Bin Wang
Keyword(s):  
Control System ◽  
Pid Control ◽  
Cascade Control ◽  
Liquid Level ◽  
Water Tank ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Adaptive Fuzzy ◽  
Cascade Control System ◽  
Self Adaptive

As liquid level cascade system has the character the issue of non-linearity ,time variability and the overshoot,tradition PID control can not meet the requirement of precise molding system. So devise a self-_ adaptive fuzzy PID control .A self-_ adaptive fuzzy PID control combined PID to control calculate way and faintness to control the advantage of method, this text permits water tank to carry on mathematics model to design the double permit a water tank liquid misty PID string class control system. Matlab/Simulink and fuzzy logic toolbox are simulated to the single loop PID control system,the cascade control system and the cascade control system based on fuzzy self-tuning PID were simulated with Simulink. The analysis and simulation results indicate that the character issue of non-linearity ,time variability and the overshoot of the liquid level cascade control system based on a self-_ adaptive fuzzy PID controller are superior to previous of two methods.

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