Studies on the Steering Characteristics of Tractor (Part V)

Stability Limit and Optimal Condition of Optimal Control System

Abstract

The responses, stabilities and optimal conditions of the steering control system of tractor were discussed by method of analogical simulation in case of the differential element in the steering control operation.
The response characteristics of system depended on the open loop gain K and the stability depended on the forecast time T₂, but the whole system was not affected by the first order time constant T₁. It seemed to be important that T₁ related to the degree of tension of operator.
Assuming that the primary forecat time T₀ equaled the secondary forecast time T₂, there were the optimal conditions of system within T₂≠0.5-1.0sec, at T₁≠1sec and K≠2(m/m). But, in case of that T₂ was independent of T₀, the better response is obtained than the above conditions. As the forecast length 1₁, was in proportion to the travel speed of tractor, in order to obtain the optimal response, the operator had to vary the forecast length proportionally to the travel speed.