Patent ID: 6119061
Filing Date: 2000-09-12
Classification: B62D

Abstract:
An apparatus for controlling an electro-hydraulic differential steering system of a work machine, comprising:a first processing device operable to receive a first signal indicative of a desired steering path, a second signal indicative of a ground speed, a third signal indicative of an engine speed, and a fourth signal indicative of a gage, the first processing device operable to transmit a fifth signal as a function of the first, second, third, and fourth signals, the fifth signal being indicative of a desired pump displacement of the steering system;a second processing device operable to receive a sixth signal indicative of a motor speed of the steering system, and to receive the third signal, the second processing device operable to transmit a seventh signal as a function of the third and sixth signals, the seventh signal being indicative of an actual pump displacement of the steering system;a proportional and integral controller coupled with the first processing device to receive the fifth signal and coupled with the second processing device to receive the seventh signal, the controller operable to transmit an eighth signal as a function of the fifth and seventh signals, the eighth signal being indicative of an error between the actual pump displacement and the desired pump displacement;a third processing device coupled with the first processing device to receive the fifth signal and with the controller to receive the eighth signal, the third processing device operable to transmit a ninth signal as a function of the fifth and eighth signals, the ninth signal being indicative of a pump displacement command signal; anda fourth processing device coupled with the third processing device to receive the ninth signal, the fourth processing device operable to transmit a tenth signal as a function of the ninth signal, the tenth signal operable to control a first portion of the steering system.