The principle of a high-precision gyroscope that keeps a satellite’s attitude stable

The control system is the core part of the satellite, and every component in it is like the organs of the satellite, controlling the various behaviors of the satellite. Advanced space launchers require highly accurate inertial navigation system. In the inertial navigation control system of satellites, there is a component called gyroscope, which is mainly responsible for sensing the attitude changes of the satellite itself, and then transmitting corresponding data in real time to ensure that the satellite flies according to the predetermined trajectory and maintains the stability of the attitude.

The Gaofen-5 satellite, launched by China in 2018, is the world’s first hyperspectral satellite to achieve comprehensive observation of the atmosphere and land in the full spectrum, filling the gap where domestic satellites are unable to effectively detect regional air pollution gases. On this satellite, the hemispherical resonant gyroscope in the attitude sensor is one of the core components of this satellite.

Satellite-borne inertial sensor is an inertial measurement system which is used to measure the attitude angular rate of spacecraft such as satellites with three orthogonal axes. Satellite-borne inertial sensor, which is a key stand-alone product in satellite attitude control system, needs to carry out reliability design of thermal engine and electromagnetic system and integration of inertial sensor system according to the design requirements of the whole satellite and adaptability of space environment.

enterprise research and development of high-precision hemispherical resonant gyro inertial sensors

Hemispherical resonant gyro is the use of hemisphere lip margin the radial vibration of a standing wave effect, a standing wave produced by hemisphere shell radial vibration along the ring to the deflection, to sensor base sensitive rotary motion of a vibrating gyroscope, is currently the highest accuracy of solid-state gyroscope, has high measuring accuracy, good stability, impact resistant radiation-hardened typical features such as ability, long working life.

Hemisphere gyroscope schematic

This kind of gyroscope is the key component of inertial measurement unit and attitude stability control of satellite or space vehicle. It can reduce the number of gyroscopes in satellite configuration and save valuable space and weight, which is of great significance to reduce the cost of satellite manufacture and launch.

In the past, most satellites used mechanical gyroscopes. In comparison, hemispherical gyroscope has three obvious advantages: high accuracy, high reliability and long life. Specifically, high precision refers to its ability to more accurately perceive small changes in the satellite attitude; High reliability refers to its good quality; Long life refers to its longer service life, especially for satellites with a long life of more than 15 years, especially for deep-space detectors with higher performance requirements.

In fact, because of the unique performance of hemispherical resonant gyroscope, the development technology of hemispherical resonant gyroscope in foreign countries is mainly concentrated in the United States, Russia and France. Among them, the United States is the most advanced technology. At present, hemispherical gyroscope has been applied in deep space exploration missions such as space vehicle navigation, satellite attitude control and planetary transit in the solar system.

At present, the potential of hemispherical gyroscope has not been fully explored. In the future, domestic enterprises will further improve the accuracy of hemispheric gyroscope, and explore the application of hemispheric gyroscope in the fields of large-capacity communication satellites, deep space exploration, high-precision three-dimensional mapping, manned spaceflight and other fields.

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