抄録
In the present paper, development of an automatic spinach harvester is discussed. The harvester equips two degrees of freedom control units such as the arm length control unit and the arm angle control unit which control a root-cutting blade following the specified path under the ground. The path the blade moving is important for successful automatic harvesting; therefore the arm length control unit and the arm angle control unit are required to track the trajectory of the specified path, exactly. The present paper focuses on the arm length control. The conventional controller employed I-PD controller, however, those performances such as the response of the unit being slowly and the unit being not be able to track the trajectory are unsatisfied. The present paper proposes a control method to improve the tracking control performance for the arm length control. First, PID controller is designed by using the robust control design procedure. Next, two degrees of freedom controller is designed by the procedure using dynamical characteristics of feedback control. Tracking control performance is verified by results of numerical simulations and field tests.
