Richard Chiang

US Patent:

6607167, Aug 19, 2003

Filed:

Feb 1, 2001

Appl. No.:

09/775126

Inventors:

Grant Wang - Hacienda Heights CA
Richard Chiang - Rancho Palos Verdes CA

Assignee:

The Boeing Company - Chicago IL

International Classification:

B64G 144

US Classification:

244173, 244164

Abstract:

A satellite system includes a solar wing moveably connected to a satellite central body. A sensor, also coupled to the satellite central body, detects the movement of the body and generates a rate signal based on that movement. Additionally, an actuator, which controls momentum, is coupled to the satellite central body with maximum torque along the thermal shock axis. Subsequently, a rate-dominated thermal shock suppression controller, which is coupled to the satellite central body, receives the rate signal from the sensor to control the actuator.

US Patent:

6980893, Dec 27, 2005

Filed:

Nov 21, 2003

Appl. No.:

10/719628

Inventors:

Richard Y. Chiang - Torrance CA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

G06F019/00

US Classification:

701 13, 244158 R, 375326

Abstract:

This invention introduces innovative filtering techniques to recover the instability phase margin loss due to time delay induced from a throughput shortage problem of a spacecraft central processor (SCP). This invention relates to digital control systems and, more particularly, to a phase recovery filtering technique to alleviate spacecraft central computer processor or (SCP) throughput shortages. This filtering technique recovers the unstable phase margin loss due to the time delay caused by the SCP throughput problem. The filtering techniques may be accomplished without schedule slip or extra cost to the project.

US Patent:

6988051, Jan 17, 2006

Filed:

Nov 14, 2003

Appl. No.:

10/713340

Inventors:

Richard Y. Chiang - Torrance CA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

G06F 101/14

US Classification:

702181, 702179

Abstract:

A method of analysis to process jitter information by using a window average statistic model to determine a pointing accuracy. The pointing accuracy ultimately determines whether or not a mission can proceed. The process includes the following: collect a signal, process the signal to produce data, insert the data from the signal into a statistical model to produce statistics, compile the statistics using the statistics model to produce a probability density function, integrate the probability density function to produce a probability distribution function, determine a pointing accuracy from the probability distribution function.

US Patent:

8131409, Mar 6, 2012

Filed:

Dec 10, 2009

Appl. No.:

12/635426

Inventors:

Tung-Ching Tsao - Torrance CA, US
Richard Y. Chiang - Torrance CA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

G05D 1/08
B64G 1/10

US Classification:

701 13, 244164

Abstract:

A system and method for gyroless transfer orbit sun acquisition using only wing current measurement feedback is disclosed. With this system and method, a spacecraft is able to maneuver itself to orient its solar panel to its maximum solar exposure spinning attitude. The disclosed system and method involve controlling a spacecraft maneuver using only the solar wing current feedback as the sole closed-loop feedback sensor for attitude control. A spin controller is used for controlling the spacecraft spin axis orientation and spin rate. The spin controller commands the spacecraft spin axis orientation to align with an inertial fixed-direction and to rotate at a specified spin rate by using a momentum vector. In addition, a method for estimating spacecraft body angular rate and spacecraft attitude is disclosed. This method uses a combination of solar array current and spacecraft momentum as the cost function with solar wing current feedback as the only closed-loop feedback sensor.

US Patent:

20050131592, Jun 16, 2005

Filed:

Dec 15, 2003

Appl. No.:

10/737588

Inventors:

Richard Chiang - Torrance CA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

G06F007/00

US Classification:

701013000

Abstract:

A method for in-flight stability margin assessment includes steps of: exciting a control system with a wide band spectrum excitation signal to produce in-flight data; storing the in-flight data in an on-board computer during operation of a spacecraft mission; downloading the in-flight data via telemetry during operation of the spacecraft mission; estimating a system sensitivity function by taking the ratio of an output power spectrum to an input power spectrum; and determining stability margins of the attitude control system from the system sensitivity function by determining a gain margin GM and a phase margin PM from the formulas: where “a” is the reciprocal of the peak of the system sensitivity function. The method optionally includes redesigning and providing a new control law to the control system if deemed necessary.

US Patent:

20050230559, Oct 20, 2005

Filed:

Mar 31, 2004

Appl. No.:

10/814516

Inventors:

Richard Chiang - Torrance CA, US

International Classification:

B64G001/26
B64G001/36

US Classification:

244165000, 244169000, 244171000

Abstract:

A method for acquiring a target from a vehicle including a sensor mounted thereon having a field of view centered on boresight. The method includes rotating the sensor about a first fixed axis, rotating the sensor about a second fixed axis generally perpendicular to the first axis as the sensor is rotated about the first axis, moving the sensor so the boresight is aligned with the target, and stopping movement of the sensor when the boresight is aligned with the target.

US Patent:

20130221160, Aug 29, 2013

Filed:

Feb 18, 2013

Appl. No.:

13/769489

Inventors:

THE BOEING COMPANY - , US
Richard Y. Chiang - Torrance CA, US

Assignee:

THE BOEING COMPANY - Chicago IL

International Classification:

B64G 1/26
B64G 1/28
B64G 1/36

US Classification:

244165, 244171, 244169

Abstract:

A system and a method for commanding a spacecraft to perform a three-axis maneuver purely based on “position” (i.e., attitude) measurements. Using an “inertial gimbal concept”, a set of formulae are derived that can map a set of “inertial” motion to the spacecraft body frame based on position information so that the spacecraft can perform/follow according to the desired inertial position maneuvers commands. Also, the system and method disclosed herein employ an intrusion steering law to protect the spacecraft from acquisition failure when a long sensor intrusion occurs.

US Patent:

20140231589, Aug 21, 2014

Filed:

Feb 14, 2014

Appl. No.:

14/181492

Inventors:

- Chicago IL, US
Richard Y. Chiang - Torrance CA, US

Assignee:

The Boeing Company - Chicago IL

International Classification:

B64G 1/36
B64G 1/44
B64G 3/00

US Classification:

244171, 2441581, 2441727

Abstract:

An attitude estimator that uses sun sensor outputs as the only attitude determination measurements to provide three-axis attitude information. This is accomplished by incorporating the Euler equation into the estimator. An unscented Kalman filter is employed to accommodate various nonlinear characteristics and uncertainties of the spacecraft dynamics and thus improve the robustness and accuracy of the attitude estimate.