Browsing by Author "Pietarinen, Julius"

Soil compaction has a major effect on the soil fertility. It is important to find the compacted regions in the field for preventive actions. With a soil penetrometer, it is possible to find compactions from the soil. Hand-operated penetrom- eters are physically demanding to operate. By automating the measurement with a machine, the stress can be removed from the user, acquire higher amounts of data and achieve more accurate and consistent data, in comparison to manual measurement techniques. Machine automation achieves constant penetration speed and higher forces than manual op- eration while being not dependent on the user. The built automated penetrometer (AP) can be attached to an ATV or other small offroad machine such as a field robot. The automated penetrometer was built using a S-force sensor and ballscrew operated by a stepper motor. The force sensor is mounted on a sled running on linear guiderails. The system control is done with an Arduino-microcontroller and data processing with a RasberryPi – minicomputer. Surface moisture is measured with the Meter Teros 10 – capac- itive soil moisture sensor during the operation. Initial tests were done in the Viikki research farm, Helsinki, Finland on a perennial grass ley field. The same measure- ments were done from the same areas with proven commercial Eijelkamp soil penetrologger. AP was found to be prac- tical and useful measurement device. With the material costs of 2000 euros, it is significantly cheaper compared to the commercial device. AP data had smaller variance compared to Eijelkamp. Open-source code makes easy to do modifi- cations and changes on the machine. Integrated computer makes real time data collection and processing easy. The developed measurement device will be later implemented to an automated field robot use.