Control system of the malaxing state for the olive paste based on computer vision and fuzzy logic

The olive paste preparation is one of the most important task within the olive oil elaboration process. It greatly determines the quality of the obtained oil, and imposes an upper bound on the achievable extraction yield. Currently, the malaxing state control of the olive paste is performed by the master miller, who observes periodically the paste inside the thermomixer and acts on variables manually. In this paper, the implementation of a new methodology to control the malaxing state of the olive paste is presented. The methodology is based on a software sensor that obtains some olive paste features from the acquired images inside the thermomixer, such as granularity, presence of floating oil and viscosity. This software sensor is formed by two camera devices, and it is coded by image processing algorithms from textural and color information. Concretely, the grey level co-ocurrence matrix and the segmentation method based on threshold, were employed. Also, a fuzzy controller was designed to act automatically on the thermomixer variables. This controller is based on the master miller expert knowledge, and it allows to adjust the malaxing time needed to prepare the olive paste to the minimum value. This fact supposes a significative improvement in the energy consumption of the plant.