2017 年 83 巻 851 号 p. 16-00531
In the present paper, development of an automatic spinach harvester is discussed. Our research group has been developing a prototype harvester and many filed tests have been successfully executed. The field test results show that spinach can be picked up automatically without being grasped after their roots being cut at specified position in soil. The harvester equips two degrees of freedom control units, such as the arm length control unit and the arm angle control unit, for controlling a root-cutting blade which follows the specified path under the ground. In the present paper, modeling and control design for the arm length control is discussed. First, a control design model is developed by several system identification techniques. Next, an I-PD controller is designed by the robust control design procedure. Control performance is verified by numerical simulations and field tests.