A single letter positioning method with a global convergence

Abstract

The invention relates to the technical field of underwater positioning, in particular to a single-beacon positioning method for an underwater vehicle. A single-beacon positioning method for underwater vehicles with global convergence. Underwater vehicles are equipped with hydrophones, Doppler velocimeters, depth gauges, attitude and heading reference systems, and GPS; underwater acoustic beacons broadcast periodically Underwater acoustic signal; the present invention converts the nonlinear single-beacon positioning model in a discrete state into a linear time-varying model through state augmentation; the relative velocity between the underwater vehicle and the water and the attitude and heading of the vehicle in the obtained satellite coordinate system , to perform Kalman filter prediction; when obtaining ocean current velocity observation, depth gauge observation, and hydroacoustic signal transmission time, the ocean current velocity, depth, and hydroacoustic signal transmission time are updated through Kalman filtering respectively. Under the premise that the positioning model is observable, this method has global exponential convergence.

Description

technical field

[0001] The invention relates to the technical field of underwater positioning, in particular to a single-beacon positioning method for an underwater vehicle. Background technique

[0002] Accurate position feedback is the basis for underwater vehicles to complete established underwater tasks. Due to the rapid attenuation of underwater electromagnetic wave signals, the GNSS system, which is widely used in land and sky positioning, cannot be applied underwater. The existing mainstream underwater positioning methods include dead reckoning methods represented by inertial navigation and underwater acoustic positioning methods represented by long baseline positioning. Among them, inertial navigation equipment tends to produce large cumulative errors over time, and cannot be used for underwater positioning for a long time, and high-precision inertial navigation equipment is extremely expensive, which limits its application in underwater vehicles. The existing main...

Examples

Embodiment 1

[0161] Embodiment 1, see attached figure 1 , a single-beacon positioning method for underwater vehicles with global convergence. The underwater vehicle is equipped with hydrophones, Doppler velocimeters, depth gauges, attitude and heading reference systems, and GPS; broadcasting an underwater acoustic signal; the method comprising the steps of:

[0162] A. Take any point in the positioning area as the origin, and set the east, north, and sky directions as x, y, and z axes respectively to establish an underwater local inertial coordinate system.

[0163] B. Obtain the initial position of the underwater vehicle in the underwater local inertial coordinate system through the equipped GPS.

[0164] C. Establish and discretize the kinematics model and observation model of the underwater vehicle, and construct a nonlinear single-beacon positioning model.

[0165] The establishment method of the kinematic model is as follows:

[0166] Define the position vector as:

[0167] p=[x y...

Embodiment 2

[0310] Embodiment 2, the method described in Embodiment 1 is verified by simulation data.

[0311]As a comparison, this embodiment also shows the positioning results of the traditional underwater single-beacon positioning method based on the extended Kalman filter (EKF) for position calculation. The overall simulation time is 5000 seconds, and the simulated effective speed of sound is constant at 1500 m / s during the whole movement process. The simulated ocean current speeds in three directions are -0.1 m / s, 0.2 m / s and 0.1 m / s respectively. The simulated underwater acoustic signal transmission period is 10 seconds, that is, the underwater acoustic signal transmission time update period is 10 seconds. The sampling period of the simulated Doppler speedometer, attitude and heading reference system and depth gauge is 0.1 second (equivalent to 10Hz sampling frequency), that is, the system discrete period, ocean current velocity update period and aircraft depth update period are all...

technical field

[0001] The invention relates to the technical field of underwater positioning, in particular to a single-beacon positioning method for an underwater vehicle. Background technique

[0002] Accurate position feedback is the basis for underwater vehicles to complete established underwater tasks. Due to the rapid attenuation of underwater electromagnetic wave signals, the GNSS system, which is widely used in land and sky positioning, cannot be applied underwater. The existing mainstream underwater positioning methods include dead reckoning methods represented by inertial navigation and underwater acoustic positioning methods represented by long baseline positioning. Among them, inertial navigation equipment tends to produce large cumulative errors over time, and cannot be used for underwater positioning for a long time, and high-precision inertial navigation equipment is extremely expensive, which limits its application in underwater vehicles. The existing main...

Examples

Embodiment 1

[0161] Embodiment 1, see attached figure 1 , a single-beacon positioning method for underwater vehicles with global convergence. The underwater vehicle is equipped with hydrophones, Doppler velocimeters, depth gauges, attitude and heading reference systems, and GPS; broadcasting an underwater acoustic signal; the method comprising the steps of:

[0162] A. Take any point in the positioning area as the origin, and set the east, north, and sky directions as x, y, and z axes respectively to establish an underwater local inertial coordinate system.

[0163] B. Obtain the initial position of the underwater vehicle in the underwater local inertial coordinate system through the equipped GPS.

[0164] C. Establish and discretize the kinematics model and observation model of the underwater vehicle, and construct a nonlinear single-beacon positioning model.

[0165] The establishment method of the kinematic model is as follows:

[0166] Define the position vector as:

[0167] p=[x y...

Embodiment 2

[0310] Embodiment 2, the method described in Embodiment 1 is verified by simulation data.

[0311]As a comparison, this embodiment also shows the positioning results of the traditional underwater single-beacon positioning method based on the extended Kalman filter (EKF) for position calculation. The overall simulation time is 5000 seconds, and the simulated effective speed of sound is constant at 1500 m / s during the whole movement process. The simulated ocean current speeds in three directions are -0.1 m / s, 0.2 m / s and 0.1 m / s respectively. The simulated underwater acoustic signal transmission period is 10 seconds, that is, the underwater acoustic signal transmission time update period is 10 seconds. The sampling period of the simulated Doppler speedometer, attitude and heading reference system and depth gauge is 0.1 second (equivalent to 10Hz sampling frequency), that is, the system discrete period, ocean current velocity update period and aircraft depth update period are all...

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