Design of test-bed for automatic depth of furrow opening control system based on ATmega128 single chip microcomputer

To develop an automatic depth of furrow opening control system for no-till seeders, an automatic depth of furrow opening control system for indoor test-bed was designed. It was made up of a measuring unit, a controller, a driving board, hydraulic system, adjusting mechanism, an opener, and so on. And it achieved tracking control of the depth of furrow opening. The results indicated that when the depth of furrow opening was 50 mm deeper than the desired value, the steady-state response time was about 0.48 s ,and when that is shallower than the desired value ,the steady-state response time was about 0.6 s, The maximum error of them both were less than 10 mm. The results also showed that when the undulation slope of surface imitating board was smaller(motor speed was about 10 r/min), the dynamic response error was limited to -30-30mm ,when that was bigger (motor speed was about 25 r/min), the dynamic response error was limited to -60-40 mm. The imitating static and dynamic response experiment could be carried out based on this test-bed for automatic depth of furrow opening control system, while control strategy should be studied further to decrease time of improve the performance of the system.