1 modern gyro technology
Electromechanical rotor gyro technology with suspension support.
Electromechanical rotor gyroscope is a kind of gyroscope based on classical mechanics principle. Its principle is to measure angular velocity and angular deviation by using the stability and precession characteristics of rigid body rotating around the axis of symmetry at high speed.
The development of suspended rotor gyro technology has been very mature so far. At present, the accuracy of single-axis liquid floating gyro has reached 0.001/h h, which can be better than 0.0005/h after using beryllium float, and the accuracy of triple floating gyro is better than 1.5× 10-5/h, and it is reported that the accuracy of the fourth generation triple floating gyro can even be achieved. Dynamically tuned gyro technology is small in size and light in weight, which is a great innovation of rotor gyro technology. The accuracy of foreign products can reach 0.001/h h, but the electrostatic gyro with vacuum electrostatic suspension technology has no contact friction on its rotor and the friction disturbance torque is almost zero. It is recognized as the rotor gyro with the highest accuracy at present, and the typical accuracy is generally10-4 ~10-5/h.
1.2 optical gyro technology.
1) laser gyro technology. Laser gyro is a kind of gyro based on Sagnac effect. Its principle is to measure the angular velocity by measuring the optical path difference of two light waves propagating in the opposite direction along the same circular path. 1963, the American company Sperry successfully developed the ring laser gyro for the first time. 1975, Honeywell developed a mechanically dithered laser gyro, and the strapdown inertial navigation system using laser gyro technology really entered the practical stage. At the end of 1990s, Litton Company developed a four-frequency differential laser gyro without mechanical jitter, with an accuracy of 0.001/h.h. At present, Honeywell's latest GG 1389 laser gyro has reached an accuracy of 0.000 15/h. 2) fiber optic gyro technology. Fiber optic gyro and laser gyro have the same principle, but the difference is that optical fiber is used as the laser loop, which can be regarded as the second generation laser gyro. Because the optical fiber can be wound, the length of the laser ring of the fiber optic gyro is greatly increased compared with that of the ring laser gyro, and the detection sensitivity and resolution are also improved by several orders of magnitude, which effectively overcomes the locking problem of the laser gyro. FOG 2500 is a high-precision fiber optic gyroscope produced by Northrop Grumman Company in the United States. Its maximum dynamic range is 100 /s, its scale factor is 0.0 1 arc second, its scale factor stability is 1ppm, its random walk is 0.0006/h, and its drift rate is 0.00/kloc.
1.3 MEMS gyro technology.
In the late 1980s, due to the introduction of micro/nano, micro-electromechanical systems (MEMS) and other technologies, micro electro mechanical systems based on MEMS came into being. Micro electro mechanical systems is a gyroscope based on Coriolis effect. Its principle is to use Coriolis force to transfer energy and excite one vibration mode of the resonator to another. The amplitude of the latter vibration mode is proportional to the input angular velocity, and the angular velocity can be measured by measuring the amplitude.
Micro electro mechanical systems is a subminiature angle measuring device fabricated on a monocrystalline silicon wafer by using the deep reactive ion etching (DRIE) technology in silicon micromachining technology. At present, the compensation accuracy of silicon micromachined surface vibration gyroscope made abroad has reached1~1h, the allowable ambient temperature can reach -40 ~ 85℃, and it can withstand the impact of external speed. It has been applied to tactical weapons and other low-precision fields in batches. On the whole, MEMS gyroscope is only in the category of medium and low accuracy at present, and its accuracy will be higher and higher in the future. The research on MEMS in China began in the 1990s, and it is still in the basic theoretical research stage. Due to the limitation of technology and precision, the performance and stability of the products are far behind those of foreign countries.
1.4 new gyro technology.
With the deepening of gyro technology research, new types of gyroscopes, such as quantum gyroscopes, nuclear magnetic vibrating gyroscopes, superfluid gyroscopes and superconducting gyroscopes, are constantly emerging. Quantum gyro is more promising. Quantum gyroscope, also known as atomic gyroscope, is the highest resolution gyroscope at present. Atomic gyroscope can be divided into atomic interference gyroscope and atomic spin gyroscope from the measurement mechanism. Its principle is similar to that of optical gyro, which uses the interference of atomic waves formed by homologous atomic beams to produce Sagnac effect similar to optics, and measures angular velocity by measuring its phase difference. In fact, atomic wave interference is used instead of light wave interference. Because the mass of atoms is much greater than the relative mass of photons, in the same closed-loop region, the sensitivity of atomic interferometric gyroscopes to rotation is more than 10 orders of magnitude higher than that of optical gyroscopes. Atomic spin gyro is similar to rotor gyro, which measures angular velocity by using the moment of momentum and the axis of magnetic moment of nuclear or electron spin in inertial space. Because of its ultra-high precision potential, atomic gyro is expected to become the dominant strategic gyro to lead the future gyro upgrade. At present, the United States has developed an atomic gyro with an accuracy of 6× 10-5/h, and hopes to develop an ultra-high precision inertial navigation system with a speed of 5 m/h. ..
2 application of gyro technology
2. 1 electromechanical rotor gyro.
At present, high-precision electromechanical gyroscopes (including liquid floating gyroscopes and electrostatic gyroscopes) are the leading products in the high-precision market. High-precision liquid-floating gyroscopes are mainly used in navigation systems of long-range missiles, military aircraft, ships and submarines, medium-precision liquid-floating gyroscopes are used in platform compasses, missiles, spacecraft and satellites, and higher-precision three-floating gyroscopes are used in strategic weapons and aerospace fields. For example, TGG three-floating gyroscope used in the floating platform system guided by long-range strategic missiles in the United States has always occupied an unshakable position. At present, electrostatic gyro is still the first choice of inertial reference device for high-precision inertial navigation system, and it will not be replaced in the field of high-performance inertial navigation system in the next 10 ~ 20 years. In China, the inertial navigation system of liquid floating gyro platform and the four-axis platform system of dynamically tuned gyro have been applied to the Long March series of launch vehicles.
2.2 optical gyro.
Optical gyro has the advantages of all solid state, no rotating and friction parts, long life, large dynamic range, instant start, simple structure, small size, light weight and easy digitization of information, which is incomparable to rotary gyro. Therefore, the optical gyro gradually replaces the rotor gyro, which has always occupied a leading position in the field of medium and high precision applications, especially for strapdown guidance systems. Foreign all-solid-state structure, all-digital, low-power fiber optic gyroscopes have become mature, covering the range of high, medium and low precision, and are widely used in various fields, becoming one of the leading gyroscopes in the field of inertial technology. Fiber optic gyroscopes are gradually replacing laser gyroscopes in high-precision applications such as spacecraft and ships, and will occupy a certain share in strategic high-precision applications in the future, and then gradually replace electrostatic gyroscopes.
In recent years, China's optical gyro technology has made rapid progress and reached the international advanced level. Fiber optic gyro and laser gyro inertial navigation devices have also been widely used in tactical guidance weapons, aircraft, ships, launch vehicles, spacecraft and so on. A new laser strapdown system with drift rate of 0.0 1 ~ 0.02/h is applied to new fighters. Fiber optic gyro strapdown inertial navigation system with drift rate less than 0.05/h is applied to ships and submarines.
2.3 MEMS gyroscope.
MEMS gyroscope, like optical gyroscope, has no high-speed rotating rotor in structure. Besides most advantages of optical gyroscope, it is smaller in size (micron/nanometer), lower in power consumption, lower in price and more widely used.
Since 1990s, MEMS gyroscopes have been used in military fields, such as supersonic fighters, cruise missiles and unmanned reconnaissance aircraft. With the further development of micro/nano machining technology and the further improvement of size and accuracy, MEMS gyroscope will replace fiber optic gyroscope and get better application prospects. Micro electro mechanical systems has the advantages of low cost, small size, fast response, large dynamic range and adaptability to harsh environment, and it will have a broader market in civil fields such as automobile manufacturing, digital electronic equipment, aircraft aided navigation, biology, medical care and industrial equipment, and is expected to occupy the whole low-end market.
After decades of development, gyro technology has made great progress, providing strong technical support for the development of aerospace, aviation, navigation and weapons and equipment. However, due to the restriction of basic industrial level such as materials, microelectronic devices, precision and microstructure processing technology, the development of modern gyro manufacturing technology has obvious gap with some developed countries in the world. In the future, it is necessary to continuously improve the accuracy, reliability, environmental adaptability, product consistency and long-term stability of parameters of products, especially to increase the research on the basic theory, applied materials, methods and processes of gyro technology and improve the level of inertial instruments.
;