A mechatronic approach to handling and grading of soft fruit

Production of fruit is a major industry in Australia. The fruit is either intended for fresh market or processed for secondary and canned products. In both cases the maturity of the fruit is an important criterion determining the time of the harvest or the stage of processing of the fruit. The research work presented in this thesis primarily suggests a simple but efficient method for handling of soft fruit and measuring its flesh firmness. In brief, in order to measure the force applied to the frioit by the gripper and measuring its firmness, the armature current of the motor driving the gripper is monitored and analysed, particularly at the time of contact of the gripper's fingers with the fmit. The features extracted from armature current are then used in a pattern recognition system to measure the maturity of the samples.