Attitude and heading reference system

Abstract

This disclosure provides an attitude and heading reference system for installation on a moving vehicle, comprising a gyroscope, an accelerometer, and computing elements configured to perform an attitude estimation subsystem. The attitude estimation subsystem includes a dynamic detection module, a computing module, a complementary filtering module, and an output module. The dynamic detection module determines whether the moving vehicle is stationary. The computing module calculates a first yaw angle, a first roll angle, a first pitch angle, a second roll angle, and a second pitch angle when the moving vehicle is stationary. The complementary filtering module calculates the ideal roll angle and the ideal pitch angle, and outputs the first yaw angle, the ideal roll angle, and the ideal pitch angle to the attitude and heading reference system. The output module outputs the first yaw angle, the ideal roll angle, and the ideal pitch angle.

Claims

1. An attitude and heading reference system, configured on a mobile vehicle, comprising: a gyroscope for sensing first sensing information; and an accelerometer configured corresponding to the gyroscope for synchronously sensing second sensing information corresponding to the first sensing information. The system also includes a computing element electrically connected to the gyroscope and the accelerometer, configured to execute an attitude estimation subsystem. The attitude estimation subsystem includes: a dynamic detection module communicatively coupled to the accelerometer, used to determine whether the moving vehicle is in a stationary state based on the second sensing information; the dynamic detection module includes: a first judgment unit, used to determine whether the moving vehicle is in a first stationary state conforming to the first judgment rule using a first judgment rule; a second judgment unit, used to determine whether the moving vehicle is in a second stationary state conforming to the second judgment rule using a second judgment rule; and a decision unit communicatively coupled to the first judgment unit and the second judgment unit, used to determine that the moving vehicle is in the stationary state when the first judgment unit determines that the moving vehicle is in the first stationary state and the second judgment unit determines that the moving vehicle is in the second stationary state. A calculation module, communicatively coupled to the gyroscope, the accelerometer, and the dynamic detection module, is used to receive the first sensing information and the second sensing information when the moving vehicle is in the stationary state, and to calculate a first yaw angle, a first roll angle, and a first pitch angle using the first sensing information, and to calculate a second roll angle and a second pitch angle using the second sensing information; a complementary filtering module, communicatively coupled to the calculation module, calculates an ideal roll angle and an ideal pitch angle based on the first roll angle, the first pitch angle, the second roll angle, and the second pitch angle, and causes the attitude heading reference system to output the first yaw angle, the ideal roll angle, and the ideal pitch angle; and an output module, communicatively coupled to the complementary filtering module, is used to output the first yaw angle, the ideal roll angle, and the ideal pitch angle.

2. The attitude and heading reference system as described in claim 1, wherein, The first determination unit is configured to: (a) square one of the first acceleration values, one of the second acceleration values, and one of the third acceleration values ​​in the second sensing information, sum them up, and take the square root to obtain a total acceleration value; (b) calculate the absolute value of the difference between the total acceleration value and one of the gravitational acceleration values; and (c) determine that the moving vehicle is in the first stationary state when the absolute value of the difference is less than a first threshold.

3. The attitude and heading reference system as described in claim 1, wherein, The second determination unit is configured to: (a) for each piece of the second sensing information within a preset window size, square a first acceleration value, a second acceleration value, and a third acceleration value respectively, sum them up, and take the square root to obtain a total acceleration value; (b) aggregate multiple total acceleration values ​​within the preset window size to form a total acceleration value sequence; (c) calculate a correlation coefficient based on the total acceleration value sequence; and (d) when the correlation coefficient is less than a second threshold, determine that the moving vehicle is in the second stationary state.

4. The attitude and heading reference system as described in claim 3, wherein, The second threshold is defined as a value obtained by dividing a constant by the square root of the preset window size.

5. The attitude and heading reference system as described in claim 1 further includes a filtering module, communicatively coupled to the dynamic detection module, for filtering the second sensing information and transmitting the filtered second sensing information to the dynamic detection module.

6. The attitude and heading reference system as described in claim 5, wherein, The filtering module is a low-pass filter, which is used to filter out high-frequency sensing information in the second sensing information.

7. The attitude and heading reference system as described in claim 1, wherein, The gyroscope further comprises: a first circuit board; a light source element disposed on the first circuit board for generating a driving beam; an optical carrier; a beam guiding element disposed on at least one of the light source element and the optical carrier, connected to the light source element, for receiving the driving beam and guiding the driving beam transmission; a modulation element disposed on the optical carrier, connected to the beam guiding element, for modulating a driving phase of the driving beam and splitting or combining the received driving beam; an optical fiber ring disposed on the optical carrier, connected to the modulation element, for transmitting the driving beam split by the modulation element, and after transmission, transmitting the driving beam back to the modulation element, and then combining the driving beam by the modulation element; a second circuit board; a detection element disposed on the second circuit board, connected to the beam guiding element, for receiving the driving beam combined by the modulation element, and transmitting a detection signal accordingly; and a third circuit board. A transceiver element is disposed on the third circuit board and electrically connected to the modulation element and the detection element for transmitting and receiving the driving beam and the detection signal; a fourth circuit board; a power supply element is disposed on the fourth circuit board for providing power to the first circuit board, the second circuit board, the modulation element, the third circuit board and the fourth circuit board; and a fifth circuit board; The computing element is disposed on the fifth circuit board and electrically connected to the transceiver element to process and analyze the driving beam and the detection signal; wherein the first circuit board, the optical carrier, the second circuit board, the third circuit board, the fourth circuit board and the fifth circuit board are arranged in any combination, and any two adjacent ones are detachably assembled with each other.

8. The attitude and heading reference system as described in claim 7, wherein, The beam guiding element further includes: a wavelength division multiplexer connected to the light source element; a doped optical fiber connected to the wavelength division multiplexer; a reflective element connected to the doped optical fiber; and a circulator connected to the wavelength division multiplexer; wherein the driving beam sequentially passes through the wavelength division multiplexer, the doped optical fiber, and the reflective element, is reflected by the reflective element, and then sequentially returns through the doped optical fiber, the wavelength division multiplexer, and the circulator before being transmitted to the modulation element.

9. An attitude and heading reference method, comprising: (a) Receive first sensing information and second sensing information corresponding to the motion state of a mobile vehicle; (b) Determine whether the mobile vehicle is in a stationary state or a moving state based on the second sensing information; (c) When it is determined that the mobile vehicle is in the stationary state, calculate a first yaw angle, a first roll angle, and a first pitch angle based on the first sensing information; (d) When it is determined that the mobile vehicle is in the stationary state, calculate a second roll angle and a second pitch angle based on the second sensing information; (e) When it is determined that the mobile vehicle is in the stationary state, calculate an ideal roll angle and an ideal pitch angle based on the first roll angle, the first pitch angle, the second roll angle, and the second pitch angle; (f) When it is determined that the mobile vehicle is in the moving state, calculate the first yaw angle, the first roll angle, and the first pitch angle based on the first sensing information. (g) When it is determined that the moving vehicle is in the moving state, the ideal roll angle and the ideal pitch angle are calculated based on the first roll angle and the first pitch angle; and (h) the first yaw angle, the ideal roll angle, and the ideal pitch angle are output.

10. An attitude and heading reference system, disposed in a moving vehicle, comprising: a gyroscope for sensing first sensing information; an accelerometer for sensing second sensing information; and a computing element electrically connected to the gyroscope and the accelerometer, configured to execute a command causing the computing element to: (a) determine, based on the second sensing information, whether the moving vehicle is in a stationary state, including: (a1) Use a first judgment rule to determine whether the mobile vehicle is in a first stationary state that meets one of the first judgment rules; (a2) Using a second judgment rule to determine whether the mobile vehicle is in a second stationary state that conforms to one of the second judgment rules; and (a3) ​​When the mobile vehicle is in the first stationary state and the mobile vehicle is in the second stationary state, determine that the mobile vehicle is in the stationary state; (b) In the stationary state, calculate a first yaw angle, a first roll angle and a first pitch angle based on the first sensing information; (c) In the stationary state, calculate a second roll angle and a second pitch angle based on the second sensing information; (d) Calculate an ideal roll angle and an ideal pitch angle based on the first roll angle, the first pitch angle, the second roll angle and the second pitch angle; and (e) Output the first yaw angle, the ideal roll angle and the ideal pitch angle.

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