United States Patent [19]
Jackson
[54] METHOD AND APPARATUS FOR
IMPLEMENTING A DATABUS VOTER TO
SELECT FLIGHT COMMAND SIGNALS
FROM ONE OF SEVERAL REDUNDANT
ASYNCHRONOUS DIGITAL PRIMARY
FLIGHT COMPUTERS
[75] Inventor: Douglas O. Jackson, Mercer Island,
Wash.
[73] Assignee: The Boeing Company, Seattle, Wash.
[21] Appl. No.: 233,142
[22] Filed: Apr. 25,1994
[51] Int. CI.6 G06F 15/16; G06F 11/14
[52] U.S. CI 364/434; 364/133; 364/184;
371/36
[58] Field of Search 364/434, 556,
364/551.01, 424.06, 133, 184; 371/36;
244/76 R, 175; 395/575
[56] References Cited
U.S. PATENT DOCUMENTS 3,596,107 7/1971 Kittrell 307/204
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US005515282A
[ii] Patent Number: 5,515,282 [45] Date of Patent: May 7,1996
3,783,250 1/1974 Fletcher et al 235/153 AE
4,130,241 12/1978 Meredith et al 235/307
4,849,893 7/1989 Page et al 364/434
4,967,347 10/1990 Smith et al 364/200
4,995,040 2/1991 Best et al 371/36
5,278,843 1/1994 Ako 371/36
5,297,052 3/1994 Mclntyre et al 364/453
Primary Examiner—Michael Zanelli
Attorney, Agent, or Firm—James P. Hamley
[57] ABSTRACT
Asynchronous, triple redundant primary flight computers (PFC's) (12, 14, 16) produce output command signals carried over a data bus (18) to control redundant actuators (32, 34, 36) in an aircraft flight control system. To prevent the transmission of a fault and a force fight among the redundant actuators, which drive a common aircraft control surface (50), a databus voter (52, 54, 56) associated with each PFC receives all PFC commands and, in accordance with a selection algorithm, outputs a voted one of the PFC command signals. A databus voter monitor, (144) associated with each databus voter, deactivates its associated databus voter if it detects a voted command signal which is inconsistent with the selection algorithm.
19 Claims, 8 Drawing Sheets
