Soft-sensing method of color measurement in batch dyeing process of knitted cotton with reactive dyes

For the on-line measurement of the fabric color in the batch dyeing process, a novel method is proposed based on soft-sensor. In this method, the concentrations of the dyestuff in a jet dyeing machine are selected as the soft sensor's inputs, and the the fabric color is the output. A nonlinear model, which relates the absorbance with the concentrations of the dyestuff, is obtained based on the experiments and the regression analysis method. Using this nonlinear model, the concentrations of the dyestuff during the dyeing process are measured by the extended Kalman filter(EKF). Further, the soft-sensing model is proposed to predict the fabric color by the obtained concentrations of the dyestuff. The numerical results for the soft-sensing method of color measurement in the dyeing process of knitted cotton using reactive dyes are compared to the experimental results, leading to good agreement between theory and experiment. This demonstrates that this soft-sensing model is able to predict the fabric color in the textile industries for the batch dyeing process.