Miniaturized smart self-calibration electronic pointing method and system

• US 20090070058A1
• Filed: 08/14/2008
• Published: 03/12/2009
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: American GNC Corporation
• Original Assignee: American GNC Corporation
• Inventors: Lin, Ching-Fang
• Granted Patent: US 8,311,757 B2
• Time in Patent Office: Days
• US Class Current: 702/93
• CPC Class Codes: F41G 1/50 for trench mortars or for other mortars
• CPC Class Codes: F41G 3/02 using an independent line of sight
• CPC Class Codes: F41G 3/14 Indirect aiming means
• CPC Class Codes: F41G 3/18 Auxiliary target devices adapted for indirect laying of fire
• CPC Class Codes: F41G 5/06 using electric means for remote control
• CPC Class Codes: G01C 21/183 Compensation of inertial measurements, e.g. for temperature effects

Abstract

An innovative configuration of Miniaturized Smart Self-calibration EPD for mortar applications, as the azimuth/heading and elevation measurement device. This innovative EPD configuration uses only two FOGs or DTG and accelerometers and it is self-contained. This leads to a new EPD implementation that produces a small and light device with lower cost and adequate accuracy for the small dismounted mortar applications.

Claims

1. A miniaturized smart self-calibration electric pointing device, comprising:

a sensors/actuator assembly wherein further comprises;

a 2-axis DTG (Dynamically Tuned Gyro) for sensing the earth rate and said device angular motion;

a first accelerometer;

a second accelerometer with said first accelerometer for sensing gravity; and

an indexing device carrying said 2-axis DTG, said first accelerometer, and said second accelerometer for real-time multiple position sensor calibration;

a sensor interface circuits; and

a computation platform electrically connected with said sensors/actuator assembly by said sensor interface circuits for processing measurement from said sensors/actuator assembly for pointing.

2. The device, as recited in claim 1, wherein said indexing device moving said 2-axis DTG, said first accelerometer, and said second accelerometer to more than two positions when said system is starting or during said system operation for sensor calibration.

3. The device, as recited in claim 2, wherein said device is using two-position method for sensor calibration.

4. The device, as recited in claim 2, wherein said device is using multi-position method for sensor calibration.

5. The device as recited in claim 3, wherein said sensors/actuator assembly further comprises an AGNC CPN (Coremicro®

Palm Navigator) communicatively connected with said indexing device for testing and motion detection aiding.

6. The device as recited in claim 4, wherein said sensors/actuator assembly further comprises an AGNC CPN (Coremicro®

Palm Navigator) communicatively connected with said indexing device for testing and motion detection aiding.

7. The device, as recited in claim 5, wherein said sensor interface circuits further comprises:

2 channels high accuracy ADC module for said two accelerometer measurement outputs; and

2 channels high accuracy ADC module, for two DTG angular measurement outputs, wherein said ADC) modules have standard interfaces to the computation platform.

8. The device, as recited in claim 6, wherein said sensor interface circuits further comprises:

2 channels high accuracy ADC module for said two accelerometer measurement outputs; and

2 channels high accuracy ADC module, for two DTG angular measurement outputs, wherein said ADC) modules have standard interfaces to the computation platform.

9. A method for self-calibration electric pointing, comprising steps of:

(a) powering on a EPD system and position it on a stationary base;

(b) resetting said EPD indexing devise controller and let Δ

θ

₀=0;

(c) waiting 2 to 3 minutes for the DTG to fully start;

(d) performing ADC to get two channel gyro measurement data;

(e) processing said gyro measurement data by two low-pass filters;

(f) averaging said gyro data over 10 seconds time period;

(g) using said standard deviation of the gyro data over 10 seconds to verify if said EPD system is really on a stationary base;

(h) saving said obtained data as packet 1;

(i) moving said EPD indexing devise and point the EPD X axis unit to a second angular position and on said stationary base and let Δ

θ

₁=20 to 30 degrees;

(j) processing said gyro measurement data by two low-pass filters;

(k) averaging said DTG data over 10 seconds time period;

(l) using said standard deviation of the gyro data over 10 seconds to verify if said EPD system is really on a stationary base;

(m) saving said obtained data as packet 2;

(n) repeating step (h) to step (l) until data packet 3 is obtained; and

(o) using said obtained data as packets 1, 2, and 3 to calculate a 2 DTG biases; and

(p) processing said obtained DTG biases for said EPD system.