The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1999
Filed:
Jul. 10, 1997
Naoki Yamaguchi, Nishiuomiya, JP;
Osamu Akamatsu, Akashi, JP;
Nabco, Ltd., Nichi-Ku Kobe, JP;
Abstract
A fluid pressure control device having a 3-position solenoid valve which is controlled to switch between a supply position, an overlapping position, and an exhaust position, using a drive command value corresponding to a pressure command signal. It also has a drive command setting unit which computes a drive command value for driving the 3-position solenoid valve into a predetermined position, in order to make the pressure command signal and a feedback signal of the output pressure of the 3-position solenoid valve coincide and a compensating value setting unit which computes a compensating value to be added to or subtracted from the above-mentioned drive command value, in accordance with the pressure differential between the above-mentioned pressure command signal and feedback signal, and the proportion of change in the feedback signal. The fluid pressure control device further has an addition and subtraction processing unit which computes a compensation amount by integrating the compensating value output from the compensating value setting unit when the drive command value has strayed from the overlapping command value corresponding to the overlapping position of the 3-position solenoid valve, and adds or subtracts the above-mentioned compensation amount to or from the drive command value, in the direction departing from the above-mentioned overlapping position, so as to output a new drive command value to the 3-position solenoid valve.