A navigation system and precise three-point positioning method for underwater deep submersible

Abstract

The invention discloses a navigation system for an underwater bathyscaph and a precise three-point positioning method. The navigation system comprises an extremely low frequency receiving and transmitting module, a GPS receiving and transmitting module, an electronic compass, a digital signal processing unit, an MEMS inertia measurement unit and a bathyscaph center computer. According to the invention, an MEMS gyroscope and an MEMS accelerometer are employed for forming a posture measurement unit, and form an inertial combination navigation positioning system with the electronic compass, and the inertial combination navigation positioning system cooperate with a control system. When the bathyscaph is located on a water surface, the bathyscaph is switched to a GPS mode, and obtains the position information through the GPS receiving and transmitting module; when the bathyscaph is located underwater, the GPS positioning data is invalid or DOP increases to a pre-determined threshold value,the bathyscaph is switched to a dead reckoning mode, and is located via a three-point positioning method of four extremely low frequency land base stations through combining with the characteristicsof extremely low frequency electromagnetic waves in a deep sea.

Description

Technical field [0001] The invention belongs to the field of underwater positioning and navigation, and in particular relates to a navigation system and a precise three-point positioning method for an underwater deep submersible. The device has reliable characteristics such as low power consumption and high accuracy, and can realize the underwater deep submersible Precise positioning. Background technique [0002] Research in recent years has found that extremely low frequency electromagnetic waves (0.1-30-300Hz) have better penetration in the deep sea. The lower the electromagnetic wave frequency and the greater the skin depth, the easier it is to penetrate the seawater and propagate downward. The internal ocean waves should try to use low frequency bands. [0003] Electronic compass can be divided into three-dimensional electronic compass and flat electronic compass. Compared with flat compass, three-dimensional electronic compass has an inclination sensor inside, which overcome...

AI Technical Summary

Problems solved by technology

Therefore, when the receiver antenna is blocked by obstacles such as buildings and leaves or in deep sea conditions, the number of visible satellites is difficult to meet the requirements.

Due to the structural characteristics of the GPS receiver tracking loop, the GPS maneuverability is poor

The complexity of GPS navigation calculation makes the update frequency of receiver navigation information only a few hertz, which makes it difficult to meet the requirements for output frequency of navigation information under special conditions

The above characteristics make it difficult for GPS to be used as a high-performance primary navigation system. In many cases, GPS is used as an auxiliary system for the primary navigation system.

[0005] The integrated navigation system based on inertial navigation and integrated with GPS and electronic compass has a large number of applications in land, aviation, aerospace and surface carriers at home and abroad, but underwater submersibles work for a long time in the deep sea, and GPS information is in Underwater cannot be used, single inertial navigation cannot meet the positioning requirements, and because underwater deep submersibles have high requirements for power consumption, volume and accuracy, the integrated navigation system of underwater deep submersibles has not been well applied

[0006] How to make full use of the advantages of electronic compass, extremely low frequency electromagnetic wave, GPS, and strapdown inertial integrated navigation system to meet the requirements of high precision and long flight time will be a relatively difficult problem, and this system is widely used at home and abroad. None reported

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