Automatic working depth control for seed drill using ISO 11783 remote control messages

Abstract

Typical sowing depth for cereal crops is in range of 20–50mm, depending on the soil type and crop. The variation in the sowing depth causes variation in germination and the seeds placed too deep are not sprouting. To compensate the spatial variation in soil type and conditions, an automatic depth control for a seed drill was developed. The seed drill used in this study was equipped with the wedge-roller type single-disc coulters that help in the working depth regulation but an electronic system is necessary on top of that. The developed electronic control system was compatible with ISO 11783 communication standard. The working depth was measured by using multiple sensors. The control system utilises ISO 11783 remote control messages to command the auxiliary valves of the tractor over ISO 11783 on the implement side. The system was tested on the field, at first to validate the measurement system and later to test the ability of the control system to adjust the working depth. The control system was able to maintain the desired working depth within tolerance ±10mm at driving speed 10km/h. The true samples of sowing depth were compared with working depth estimate in the same spot and it was found that the sowing depth was 1.7mm shallower compared with the working depth on average.