Ultrasonic bund detection system for header of combine harvester

There are appreciable physical losses to the header of a combine harvester operating in the fields during harvesting. To reduce these losses, it is desirable to effectively control the header height of the combine harvester. In the present study, a soil bund detection system has been developed for the header of the combine harvester using an ultrasonic sensor and tested under field conditions. In the laboratory, the best among five ultrasonic sensors (HC-SR04, US-100, JSN-SR04T, GY-US42 and MB-7092) was selected based on accuracy and response of the sensor operated for 27 treatments of soil bund height, sensor height and stubble density. Consequently, the soil bund detection system was developed using the US-100 sensor, Arduino UNO R3 microcontroller and two relays to control the actuator on prototype. The results showed that during sensor selection, the US-100 sensor had a maximum accuracy of 84.83% in BH3SH1SD1 treatment and a maximum response of 91.38 readings/sec in BH2SH2SD3 treatment. Furthermore, the developed system showed a maximum accuracy of 88.89% and 85.58% without the actuator in the field and with the actuator under laboratory conditions respectively. The highest response of 64.68 and 62.70 readings/sec was recorded for systems without the actuator in the field and with the actuator under laboratory conditions respectively. The study reveals that the increase in stubble density and sensor height causes a decrease in the accuracy, while the increase in bund height significantly increases the accuracy of the system. Moreover, an increase in vehicle speed causes a decrease in the response of the system, whereas with increasing bund height and stubble density, there is an increase in the response.