Studies on the Steering Characteristics of Tractor (Part III)
Operator-Tractor Control System and Response of Steering Operation
1976 Volume 37 Issue 4 Pages 514-519
Details
1976 Volume 37 Issue 4 Pages 514-519
On the basis of the experimental results about the frequency response of the operator-tractor control system (Part II), the transfer function model was assumed such as the feedback control system and the constants of each element that composed of this system were determined with the least square method.
And from above results, the steering control response of the operator and the following performance to the course were discussed.
(1) Within the range of ω0=5 rad/sec (ω0:the fundamental frequency of the course), the steering control transfer function model of the operator can be described with the first differential element, the first order lag element and the dead time element.
(2) The time constants of the first order lag at the steering control (T1) are in inverse proportion to ω0, but their fluctuations increase rapidly out of range of ω0=2 rad/sec.
(3) The accuracy on the forecast go down with the increase of ω0, but the forecast are compensated by the steering control operations, such as the loop gain (K0K1K2K3) nearly equal 1.0, and overall of system is kept in the optimal condition.
(4) The time constant (T2) of the secondary forecast increase according with the increase of T1, but T2 shows the tendency to reach the constant value (nearly 1.0 sec) out of range of T1=2, 0 sec.
On the case of T1>2.0 sec, the operasor is possible to follow up the course by only the steering operations according to the frequency of the course, without the special efforts.
When ω0 is within range of 0.5 and 2.0 rad/ sec (T1=2.0-0.5 sec), the following of the the course can be kept with that the operator decreases T1 from 2.0 to 0.5 sec, but as ω0 is over range of 2.0 rad/sec, the following of the course is very hard.
