Design of harvest area automatic measurement system

With the development of agricultural mechanization, the application 4 combine harvester is becoming popular in China. But most of Chinese farmers do not buy combine by themselves. They pay money to the combine owner according to the harvest area instead. However, the harvest area is measured manually using tapeline, which is time-consuming, laborious and usually low-resolution. So, it is necessary to measure the harvest area in an easy, fast, reliable and especially low-cost way. In this paper, an automatic system for the harvest area measurement is presented, which calculates the area from the combine's traveled distance multiplied by the swatch width measured using ultrasonic sensor in real time. The system provides keyboard and LCD for parameter input and information display. Moreover, the calculation results can be saved in non-volatile memory and printed out through micro-printer. The system also provides serial and CAN (controller area network) bus interfaces which make it easily to communicate with other system. The design of ultrasonic swath width and traveled distance measurement units are described in detail. The static test of ultrasonic swath width measurement and system test prove that the low-cost system is stable, easy to use and has enough precision for area measurement.