Green pepper stem position detection by using a piezo sensor

Automated harvesting is still not widespread because harvesting speed and success rate of most existing harvesting robots are significantly lower than those of a skilled human worker. One of the main problems is accurate targe position detection for harvesting gripper positioning. The color and growth pattern of green pepper present a great challenge for automated harvesting since they complicate fruit stem location. Use of tactile sensing as a supplement to visual recognition is proposed to improve performance of green pepper harvesting robot. A sensor for green pepper stem detection and the results for performance evaluation tests of this sensor are presented here. The sensor consists of two piezo stack actuators and the inverse piezo effect is used to detect contact with a target. The results of performed tests support the claim that the characteristics of this sensor make it viable for the intended application.