Development and Evaluation of a Prototype Precision Harvesting Unit for Medicinal Plants - Tested on Hyssopus officinalis L.

Precision management of medicinal plant production using mechanical systems, processors, and sensors increases productivity, reduces waste, and manages production processes. This research developed a precision harvesting unit equipped with an automatic height adjustment system for utilization in harvesting machines to harvest Hyssop at an optimal height. The unit after development consisted of a power transmission system (converting rotational motion into reciprocating motion), a harvesting platform (cutter-bar, reel, and conveyor), and a system to control the vertical movement of the head. An ultrasonic sensor was employed to detect the highest part of the plant for control purposes. A central control board and a driver generated the control signal, with a stepper motor as the actuator. We measured harvesting-related variables, including dry matter, essential oil content and yield, leaf-tostem ratio, and indices related to conservation agriculture to evaluate the developed precision harvesting unit. Results showed that the unit increased the purity of the harvested plant raw material compared to the manual harvesting of Hyssop, a key to extracting more of the target substances, such as essential oil. The steady-state error of the control system measured 2% in adjusting the cutter-bar height for the optimal height of harvesting Hyssop (T15) in elevation and descension modes. [ABSTRACT FROM AUTHOR]