Method and system for automatic stabilization and pointing control of a device

• US 20060265120A1
• Filed: 08/24/2005
• Published: 11/23/2006
• Est. Priority Date: 04/02/2005
• Status: Active Grant

• Current Assignee: American GNC Corporation
• Original Assignee: American GNC Corporation
• Inventors: Lin, Ching-Fang, Lam, Ken, Coleman, Norman, Papanagopoulos, George
• Granted Patent: US 7,239,975 B2
• Time in Patent Office: Days
• US Class Current: 701/209
• CPC Class Codes: G01C 21/18 Stabilised platforms, e.g. by gyroscope

Abstract

The present invention provides a method and system for an innovative design of the automatic stabilization and pointing control of a device based on the MEMS technology, which is small enough and has acceptable accuracy to be integrated into many application systems, such as, laser pointing systems, telescopic systems, imaging systems, and optical communication systems. The stabilization mechanism configuration design is based on utilization of AGNC commercial products, the coremicro IMU and the coremicro AHRS/INS/GPS Integration Unit. The coremicro AHRS/INS/GPS Integration Unit is used as the processing platform core for the design of the MEMS coremicro IMU based stabilization mechanism.

Claims

1. A method for automatic stabilization and pointing control of a device, comprising the steps of

(a) identify a desired pointing direction of said device by providing coordinate of a target;

(b) determining a current attitude measurement of said device;

(c) computing platform rotation commands of said device using said desired pointing direction of said device and said current attitude measurement of said device;

(d) rotating said device to said desired pointing direction;

(e) visualizing said target and desired pointing direction and current direction of said device; and

(f) producing a voice representing a pointing procedure.

2. The method as recited in claim 1, in step (c), further comprising the steps of:

(c.1) transforming target positioning measurements from a target coordinate producer body coordinates to local level coordinates;

(c.2) yielding a current target state including target position estimation using said target positioning measurements;

(c.3) predicting a future target trajectory and calculating interception position and time of a projectile launched by a gun turret and said target;

(c.4) producing gun turret azimuth and elevation required for launch of said projectile; and

(c.5) producing control commands using said gun turret azimuth and elevation and said current attitude rate data of said gun turret from a IMU/AHRS to stabilize and implement said gun turret azimuth and elevation with disturbance rejection.

3. The method as recited in claim 2, in step (c.3), further comprising the steps of:

(c.3.1) extrapolating said future trajectory of said projectile using said current target state, including said current target position estimation and system dynamic matrix;

(c.3.2) computing time of said projectile to fly from said gun turret to interception position; and

(c.3.3) computing interception position and time using said predicated future projectile trajectory and projectile flight time.

4. The method as recited in claim 1, between the step (c) and the step (d), further comprising the steps of:

combining said computed platform rotation commands with feedback signals;

computing an automatic stabilization and positioning control signal by a servo controller;

amplifying a servo controller signals;

sending said amplified servo controller signals to an actuator;

converting electric signals to torques and said torque exerted on a platform body to eliminate interference to said platform body; and

sensing a motion of said platform body and feedback a sensor signal to said servo controller.

5. The method as recited in claim 2, between the step (c.5) and the step (d), further comprising the steps of:

combining said computed platform rotation commands with feedback signals;

computing an automatic stabilization and positioning control signal by a servo controller;

amplifying a servo controller signals;

sending said amplified servo controller signals to an actuator;

converting electric signals to torques and said torque exerted on a platform body to eliminate interference to said platform body; and

sensing a motion of said platform body and feedback a sensor signal to said servo controller.

6. The method as recited in claim 3, between the step (c.5) and the step (d), further comprising the steps of:

combining said computed platform rotation commands with feedback signals;

computing an automatic stabilization and positioning control signal by a servo controller;

amplifying a servo controller signals;

sending said amplified servo controller signals to an actuator;

converting electric signals to torques and said torque exerted on a platform body to eliminate interference to said platform body; and

sensing a motion of said platform body and feedback a sensor signal to said servo controller.

7. An automatic stabilization and positioning control system for a device, comprising:

an attitude producer determining current attitude and attitude rate measurements of said device;

a target coordinate producer measuring a desired pointing direction of said device by capturing and tracking a target, wherein said target coordinate producer is adapted for capturing and tracking said target to measure said desired pointing direction of said pointed device;

an actuator rotating said device to said desired pointing direction, wherein said actuator changes said current attitude of a pointed device to bring said pointed device into closer correspondence with a desired orientation;

a pointing controller computing platform rotation commands to said actuator using said desired pointing direction of said device and said current attitude measurement of said device to rotate said device, wherein said pointing controller determines platform commands to said actuator by using errors between said desired pointing direction and said current direction of said pointed device; and

a visual and voice device for providing an operator with audio and visual signals including displaying said desired pointing direction and current attitude of said device, target trajectory, and producing a voice representing a pointing procedure.

9. The system, as recited in claim 7, wherein said target coordinate producer comprises an Infrared sensor (IR), Radio frequency radar (RF), Laser radar (LADAR), and CCD (Charge couple devices) camera.

10. The system, as recited in claim 7, wherein said pointing controller comprises a measurement data processing module transforming target positioning measurements, a target position estimator yielding a current target state including target position estimation using said target positioning measurements, a target position predictor predicating a future target trajectory and calculating an interception position and time of a projectile launched by a gun turret and said target;

a fire control solution module producing a gun turret azimuth and elevation required for launch of said projectile, and a device control command computation module producing control commands to said actuator using said required gun turret azimuth from said attitude producer to stabilize and implement said required gun turret azimuth and elevation with disturbance rejection.

11. The system, as recited in claim 9, wherein said pointing controller comprises a measurement data processing module transforming target positioning measurements, a target position estimator yielding a current target state including target position estimation using said target positioning measurements, a target position predictor predicating a future target trajectory and calculating an interception position and time of a projectile launched by a gun turret and said target;

a fire control solution module producing a gun turret azimuth and elevation required for launch of said projectile, and a device control command computation module producing control commands to said actuator using said required gun turret azimuth from said attitude producer to stabilize and implement said required gun turret azimuth and elevation with disturbance rejection.

12. The system, as recited in claim 10, wherein said target position estimator is a Kalman filter.

13. The system, as recited in claim 11, wherein said target position estimator is a Kalman filter.

14. The system, as recited in claim 10, wherein said target position predictor comprises a target position extrapolation module extrapolating said future trajectory of said projectile using said current target state including said target position estimation and system dynamic matrix, a projectile flight time calculation module computing said time of said projectile to fly from said gun turret to said interception position, and an interception position and time determination computing said interception position and time using said predicated future projectile trajectory and projectile flight time.

15. The system, as recited in claim 11, wherein said target position predictor comprises a target position extrapolation module extrapolating said future trajectory of said projectile using said current target state including said target position estimation and system dynamic matrix, a projectile flight time calculation module computing said time of said projectile to fly from said gun turret to said interception position, and an interception position and time determination computing said interception position and time using said predicated future projectile trajectory and projectile flight time.

16. The system, as recited in claim 13, wherein said target position predictor comprises a target position extrapolation module extrapolating said future trajectory of said projectile using said current target state including said target position estimation and system dynamic matrix, a projectile flight time calculation module computing said time of said projectile to fly from said gun turret to said interception position, and an interception position and time determination computing said interception position and time using said predicated future projectile trajectory and projectile flight time.

17. The system, as recited in claim 7, wherein said attitude producer comprises a IMU/AHRS to measure said current attitude of said pointed device.

18. The system, as recited in claim 16, wherein said attitude producer comprises a IMU/AHRS to measure said current attitude of said pointed device.

19. The system, as recited in claim 7, wherein said attitude producer comprises a MEMS IMU to measure said current attitude of said pointed device.

20. The system, as recited in claim 16, wherein said attitude producer comprises a MEMS IMU to measure said current attitude of said pointed device.

8. (canceled)