VIBRATIONS LEVELS ASSESSMENT OF A ROBOTIC INTRA-ROW WEEDER USING LOW-COST DATA ACQUISITION SYSTEM

Abstract. Automated weeding is a way to increase efficiency in the control of invasive plants. Soil characteristics can influence the performance of weeder mechanisms. The objective of this work was to determine the vibrations levels of a robotic intra-row weeder mechanism for different operating conditions and provide information to correlate with soil conditions. The data acquisition system was composed of a single-board computer and a triaxial MEMS accelerometer. The computer was programmed in C++ to acquire vibration measurements. The accelerometer was mounted to the bearing housing of the rotary tine shaft. Vibrations of the weeder mechanism were first measured without soil contact for different angular velocities of the rotary tine disk. Then, vibrations were monitored in different soils (dry and moist loam soil and sand) for three angular velocities of rotary tines (25, 50 and 100 rev/min) and two tine depths (25 and 50 mm). RMS accelerations and the frequency spectrum were used to evaluate the vibrations levels. Moist loam soil and sand had the highest and lowest increases in accelerations, respectively. The analysis showed it is possible to correlate vibrational characteristics with soil conditions that may exist during intra-row weeding. In addition, mechanical vibrations in an intra-row weeder can be monitored using a low-cost and user-friendly system.