Geometry simulation of stable channel bank profile using evolutionary PSO algorithm implementation in an ANFIS model

Abstract

Forecasting the bank profile shape of stable hydraulic channels using empirical, experimental and numerical models is of special consideration among fluid mechanic and river science engineers. In the present paper, the application of soft computing methods is evaluated in predicting the geometry of stable channel cross sections. In this way, using a combination of the Particle Swarm Optimization (PSO) algorithm with an Adaptive Neuro-Fuzzy Inference System (ANFIS) model, a novel evolutionary system called ANFIS-PSO is presented. The evolutionary model performance is assessed in comparison with a simple ANFIS model. The coordinates of points located on a channel boundary in stable state were also measured by the authors using a sensor instrument in the laboratory at 4 different flow discharge rates of 1.157, 2.18, 2.57 and 6.2 l/s. The results indicate that the evolutionary ANFIS-PSO model with Root Mean Squared Error (RMSE) and Mean Absolute Relative Error (MARE) of 0.0132 and 0.1326 performed better than the ANFIS model with 0.026 and 0.1426 error values respectively (almost 97% and 10% decrease in RMSE and MARE value for the ANFIS-PSO model, respectively). This demonstrates the high ANFIS-PSO model accuracy in predicting bank profile characteristics. The robust evolutionary ANFIS-PSO proposed can be used in designing and estimating stable channel dimensions. The second-degree polynomial equation proposed by the evolutionary ANFIS-PSO model can be utilized in predicting the coordinates of other points located on a stable boundary of a channel cross section.