John S Ho

US Patent:

6915989, Jul 12, 2005

Filed:

May 1, 2002

Appl. No.:

10/136907

Inventors:

Kioumars Najmabadi - Bellevue WA, US
Chuong B. Tran - Mukilteo WA, US
John Koon-Hung Ho - Shoreline WA, US

Assignee:

The Boeing Company - Seattle WA

International Classification:

B64C013/16

US Classification:

244195, 244177, 244 75 R

Abstract:

Vibrations due to excitation of the natural modes of an aircraft's body are suppressed by an active multi-axis modal suppression system. Dedicated sensors are positioned in the aircraft at optimal locations for sensing modal induced vibrations. The sensor produced signals are processed through control logic which, in response thereto, and in response to aircraft inertial, velocity and altitude related signals produces output control signals. The control signals effect control surface deployment creating forces to suppress the natural mode induced vibrations on multiple geometric axis's. More particularly, symmetric and anti-symmetric control surface deployments are used on one or more geometric axis's to damp lateral, longitudinal, vertical and most importantly torsional vibrational modes.

US Patent:

7191985, Mar 20, 2007

Filed:

Jul 12, 2005

Appl. No.:

11/180309

Inventors:

Kioumars Najmabadi - Bellevue WA, US
Chuong B. Tran - Mukilteo WA, US
John Koon-Hung Ho - Shoreline WA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

B64C 13/16

US Classification:

244195, 244177, 244 751

Abstract:

Vibrations due to excitation of the natural modes of an aircraft's body are suppressed by an active multi-axis modal suppression system. Dedicated sensors are positioned in the aircraft at optimal locations for sensing modal induced vibrations. The sensor produced signals are processed through control logic which, in response thereto, and in response to aircraft inertial, velocity and altitude related signals produces output control signals. The control signals effect control surface deployment creating forces to suppress the natural mode induced vibrations on multiple geometric axis's. More particularly, a symmetric and anti-symmetric control surface deployments are used on one or more geometric axis'to damp lateral, longitudinal, vertical and most importantly torsional vibrational modes.

US Patent:

8024079, Sep 20, 2011

Filed:

May 20, 2008

Appl. No.:

12/123942

Inventors:

Kioumars Najmabadi - Clyde Hill WA, US
William F. Shivitz - Renton WA, US
Edward Ernest Coleman - Forest Park WA, US
John Koon-hung Ho - Shoreline WA, US
Richard D. Johnson - Edmonds WA, US
William F. Carver - Shoreline WA, US
David W. Grubb - Monroe WA, US
Robert James McIntosh - Bothell WA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

G01C 23/00
G06F 17/10
B64C 3/58

US Classification:

701 3, 701124, 244 49, 244213

Abstract:

A computer implemented method, apparatus, and computer usable program product for symmetric and anti-symmetric control of aircraft flight control surfaces to reduce wing-body loads. Commands are sent to symmetrically deploy outboard control surfaces to shift wing air-loads inboard based on airplane state and speed brake deployment. Surface rate retraction on a wing with peak loads is limited to reduce maximum loads due to wheel checkback accompanied by utilization of opposite wing control surfaces to retain roll characteristics. Airloads are shifted inboard on a swept wing to move the center of pressure forward, thereby reducing the tail load required to perform a positive gravity maneuver. In a negative gravity maneuver, speed brakes are retracted, thereby reducing the positive tail load and reducing the aft body design loads. High gain feedback commands are filtered from wing structural modes above one hertz by a set of linear and non-linear filters.