![]() | Only 14 pages are availabe for public view |
Abstract In several food processing and chemical industries, liquid is pumped and kept in interrelated coupled tanks for different usage. However, automatic control of the liquid level and flow between these tanks is a challenging problem because of the complexity and high non linearity of the mathematical model of such system. The present work aims to control the liquid level of two horizontal coupled tanks system. A comprehensive comparative study is made for different types of sliding mode control (SMC) algorithms found in literature. These algorithms are known as Proportional-Derivative Sliding Mode Control (PD-SMC), Proportional-Integral-Derivative SMC (PID-SMC), fractional order SMC and finally dynamic SMC, to evaluate the optimal algorithm. Special emphasis is put on the effect of sensor noise on the controller performance. System mathematical model is developed and simulated. Experiments including robustness to variation in plant parameters and step input disturbances are made. Control algorithms parameters are selected to optimize performance indices by using MATLAB optimization toolbox. Finally, experimental work is made to validate the simulation results. The results indicate that PD-SMC, PID-SMC, and fractional order SMC are more robust to plant parameters changes than the dynamic-SMC. However, the dynamic-SMC has a significant reduction in the chattering level compared to the other three controllers when sensor noise is added. |