1974 年 35 巻 4 号 p. 368-377
The automatic steering system which has two kinds of sensor for detecting the row of rice plant by contacting it was examined, the responses of the combine with the above system to the artificial row as the input were determined experimentally and the fundamental problems and the future principles were discussed. Moreover, by means of digital simulation technique the possibilities of utilizing the experimented automatic steering system in the actual field were investigated.
The results of experiments and computation are as follows.
For the automatic steering system with the sensors detecting the row of rice plant from both sides of row by contacting it,
1) As the delay time for restoring from steering motion to straight travel was increased, the path of the combine was disturbed because of the excessive corrections of errors.
2) As the travelling velocity was increased, the path of the combine was disturbed because of inertia effect of the mass of the combine.
3) Because of the double sensing device consisting of the main and supplementary sensor, the combine travelling at the top speed was able to track the input by means of the effect of the supplementary sensor.
4) The relationships between the dead zone widths of the sensors and travelling stability and tracking accuracy could not be found because the experiments were not produced so many.
5) The influences of the delay time, travelling velocity and dead zone width upon the phase shift between the input row and output path were not found.
6) The digital simulation of the automatic steering of the combine suggested the possibility of utilization of the experimented system in the actual field.
For the automatic steering system with the sensors detecting the row of rice plant from one side of the row, the possibility of this type of sensor was found and the experimental results are as follows.
1) As the travelling velocity was increased, the path of the combine was disturbed.
2) The combine travelling at the relatively high speed could not track the input row because of the unsuitable shape and dimensions of the constantly contacting link of the latter sensor.
3) The path of the combine travelling at lower speed was smoother than the path of the combine with the sensors detecting the row of plant from both sides of the row, itmay be because of difference of the mode of sensing.