Studies on the Steering Characteristics of Tractor (Part IV)

Steering Control Operation and Aiming Point of Course

Abstract

Tracking the course with tractor, the steering control operation was affected by the conditions of aiming the course, and these conditions depend on the distance (forecast length 1 ) from the front axle to the mark point on the course.
In this experiment, the effects of the aiming point for the steering control operation were investigated for the condition that 1 is limited compulsorily. The main results were as follow:
The differential action of the steering control operation (model 1) was gradually replaced by the proportional action (model 2) under the condition of limited forecast length. The gain constant of steering operation (K₁) was large about three times for the model 2, as compared with the model 1. Therefore, the operator has encountered some times the difficulties of steering operation for the model 2.
On the model 2, the minimum values of forecast time T₀ and T₂ (primary and secondary) were necessary to equalize the dead time (τ) of the system, and also, in the case of T₀=2τ, it seemed to be T₂=T₀.
As the forecast length l₁ was limited for the model 1, the first time lag T₁ relating to steering control operation did not have significance for T₂, because the differential action was disturbed.