Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID
To overcome the problem of poor uniformity of solid-fertilizer-dissolving devices due to lag of fertilizer dissolution, a closed-loop control system based on fuzzy proportional-integral-derivative (PID) was designed and tested. A fertilizer concentration regulation model was then established accordi...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-09-01
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| Series: | Agriculture |
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| Online Access: | https://www.mdpi.com/2077-0472/12/9/1382 |
| _version_ | 1827664558015119360 |
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| author | Xiuhua Song Hong Li Chao Chen Huameng Xia Zhiyang Zhang Pan Tang |
| author_facet | Xiuhua Song Hong Li Chao Chen Huameng Xia Zhiyang Zhang Pan Tang |
| author_sort | Xiuhua Song |
| collection | DOAJ |
| description | To overcome the problem of poor uniformity of solid-fertilizer-dissolving devices due to lag of fertilizer dissolution, a closed-loop control system based on fuzzy proportional-integral-derivative (PID) was designed and tested. A fertilizer concentration regulation model was then established according to the results. In this system, the control core was an STM32 used to feed back the fertilization concentration by detecting the electrical conductivity. For real-time adjustment of the fertilizer flow rate and water flow rate, a fuzzy PID control algorithm was utilized to compare the detected concentrations with the set concentrations. The linear relationships between quantities such as the fertilizer rate and PWM frequency, water flow rate and PWM duty ratio of the direct-current pump, and fertilizer concentration and electrical conductivity were all established to calibrate the system. The influence of the fertilizer flow rate and water flow rate on fertilizer concentration was determined by the control variable test method. The results showed a positive linear relationship between fertilizer concentration and fertilizer flow rate, while a reverse linear relationship was established between fertilizer concentration and water flow rate. After the introduction of the control system into the self-developed solid-fertilizer-dissolving device, the fertilizer concentration fluctuated near the set concentration in a range of no more than 1 g/L. After the disturbance of the fertilization device, the control system fine-tuned the device with a steady-state error of about 0.55 g/L after the system reached stability. The control system designed in this study was shown to run normally with good stability, speed, and accuracy, and with improved fertilization uniformity of the solid-fertilizer-dissolving device. This study lays the foundation for further study of fertilization control systems. It also provides a reference for the development of precise and intelligent fertigation. |
| first_indexed | 2024-03-10T01:02:40Z |
| format | Article |
| id | doaj.art-8143bd06b0644d63a3380d6a66bccf44 |
| institution | Directory Open Access Journal |
| issn | 2077-0472 |
| language | English |
| last_indexed | 2024-03-10T01:02:40Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agriculture |
| spelling | doaj.art-8143bd06b0644d63a3380d6a66bccf442023-11-23T14:33:02ZengMDPI AGAgriculture2077-04722022-09-01129138210.3390/agriculture12091382Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PIDXiuhua Song0Hong Li1Chao Chen2Huameng Xia3Zhiyang Zhang4Pan Tang5Research Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaResearch Center of Fluid Machinery and Technology, Jiangsu University, Zhenjiang 212013, ChinaTo overcome the problem of poor uniformity of solid-fertilizer-dissolving devices due to lag of fertilizer dissolution, a closed-loop control system based on fuzzy proportional-integral-derivative (PID) was designed and tested. A fertilizer concentration regulation model was then established according to the results. In this system, the control core was an STM32 used to feed back the fertilization concentration by detecting the electrical conductivity. For real-time adjustment of the fertilizer flow rate and water flow rate, a fuzzy PID control algorithm was utilized to compare the detected concentrations with the set concentrations. The linear relationships between quantities such as the fertilizer rate and PWM frequency, water flow rate and PWM duty ratio of the direct-current pump, and fertilizer concentration and electrical conductivity were all established to calibrate the system. The influence of the fertilizer flow rate and water flow rate on fertilizer concentration was determined by the control variable test method. The results showed a positive linear relationship between fertilizer concentration and fertilizer flow rate, while a reverse linear relationship was established between fertilizer concentration and water flow rate. After the introduction of the control system into the self-developed solid-fertilizer-dissolving device, the fertilizer concentration fluctuated near the set concentration in a range of no more than 1 g/L. After the disturbance of the fertilization device, the control system fine-tuned the device with a steady-state error of about 0.55 g/L after the system reached stability. The control system designed in this study was shown to run normally with good stability, speed, and accuracy, and with improved fertilization uniformity of the solid-fertilizer-dissolving device. This study lays the foundation for further study of fertilization control systems. It also provides a reference for the development of precise and intelligent fertigation.https://www.mdpi.com/2077-0472/12/9/1382fertilization uniformityclosed-loop controlsingle-chip microcomputerfuzzy PIDsolid-fertilizer-dissolving device |
| spellingShingle | Xiuhua Song Hong Li Chao Chen Huameng Xia Zhiyang Zhang Pan Tang Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID Agriculture fertilization uniformity closed-loop control single-chip microcomputer fuzzy PID solid-fertilizer-dissolving device |
| title | Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID |
| title_full | Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID |
| title_fullStr | Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID |
| title_full_unstemmed | Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID |
| title_short | Design and Experimental Testing of a Control System for a Solid-Fertilizer-Dissolving Device Based on Fuzzy PID |
| title_sort | design and experimental testing of a control system for a solid fertilizer dissolving device based on fuzzy pid |
| topic | fertilization uniformity closed-loop control single-chip microcomputer fuzzy PID solid-fertilizer-dissolving device |
| url | https://www.mdpi.com/2077-0472/12/9/1382 |
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