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:
Dec. 25, 1979
Filed:
Dec. 28, 1977
Robert L Amberg, Seattle, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A limited-slip brake control system includes a basic deceleration control circuit responsive to a wheel deceleration signal and to a selected reference deceleration signal to provide a first brake control signal which is used to modulate brake pressure applied to a braked wheel of a vehicle in order to maintain the vehicle deceleration at a selected reference deceleration representing a level of brake force generally lying in the nonslip portion of a characteristic Mu/slip curve for the vehicle. A large deviation control circuit is also responsive to the wheel deceleration signal and functions to modify the first brake control signal to cause brake pressure to be reduced when the wheel deceleration exceeds a second reference deceleration representing a level of brake force generally lying in a slip portion of the characteristic Mu/slip curve, or, corresponding to a situation where the braked wheel encounters a sudden decrease in the available coefficient of friction and is forced into a skid by the basic deceleration control circuit. A second brake control signal is also provided by the large deviation control circuit when the actual wheel deceleration exceeds a third reference deceleration, higher than the second reference deceleration, signifying that the braked wheel has gone into a deep skid, which second brake control signal is used to immediately reduce brake pressure. An initial skid circuit functions to modify the first brake control signal to minimize or eliminate the tendency of the basic deceleration control circuit to place the braked wheel into a skid upon the initial application of brake pressure, and a dynamic compensation circuit is responsive to the wheel deceleration signal to provide a compensating brake control signal which is combined with the first brake control signal in order to compensate the brake pressure command represented by the first brake control signal for apparent changes in wheel deceleration occasioned by landing gear strut assembly oscillation.