The rotor of this gyroscope demonstration prop has no power. When used for demonstration, it needs to be connected to a high-speed motor to reach a certain speed, then disconnected and placed on the platform, and the demonstration relies on the inertia of the rotor to continue running.
The real high-precision mechanical gyroscope is extremely complex, and the related technology is still confidential (military grade requires anti-interference, so mechanical gyroscopes are still used, and new laser gyroscopes are still used. (commercial applications such as aviation), the published information is only a relatively simple principle model. The civilian gyroscope is actually an angular velocity sensor, which is just the simplest application.
01 Ball Bearing Free Gyroscope
It is a classic gyroscope. The use of ball bearings for support is the earliest and most widely used support method. Ball bearings rely on direct contact and have large friction torque. The accuracy of the gyroscope is not high and the drift rate is a few degrees per hour. However, it works reliably and is still used in situations where precision requirements are not high. A free rotor gyroscope (double degree of freedom gyroscope) can measure two attitude angles by relying on the inner and outer ring axis angle sensing elements.
02 Liquid floating gyroscope
Also known as float gyroscope. The inner frame (inner ring) and rotor form a sealed spherical or cylindrical float assembly. The rotor rotates at high speed in the float assembly, and the floating liquid is filled between the float assembly and the shell to generate the required buoyancy and damping. If the buoyancy force is equal to the weight of the float assembly, it is called a fully floating gyro; if the buoyancy force is less than the weight of the float assembly, it is called a semi-floating gyro. Due to the use of buoyancy support, the friction moment is reduced and the gyroscope has higher accuracy, but friction still exists because it cannot be positioned. In order to make up for this shortcoming, magnetic levitation is usually added to the liquid levitation, that is, the floating liquid bears the weight of the float assembly, and the thrust formed by the magnetic field is used to levitate the float assembly in the center position. In addition, the dynamic pressure air film formed between the high-speed rotating rotor and the inner frame can also be used to support the rotor. This method is called dynamic pressure air flotation support. Modern high-precision single-degree-of-freedom liquid-floating gyroscopes are often triple-floating gyroscopes that use liquid levitation, magnetic levitation, and dynamic pressure air levitation. This gyroscope is more accurate than a ball bearing gyroscope, with a drift rate of 0.01 degrees/hour. However, liquid-floating gyroscopes require higher processing accuracy, strict assembly, and precise temperature control, so the cost is higher
03 Electrostatic gyroscope
Also known as electric floating gyroscope. Evenly distributed high-voltage electrodes are installed around the metal spherical hollow rotor to form an electrostatic field on the rotor, and the electrostatic force is used to support the high-speed rotating rotor. This method is a spherical support. The rotor can not only rotate around the axis of rotation, but also rotate in any direction perpendicular to the axis of rotation, so it is a free rotor gyroscope type. The electrostatic field only has suction force. The closer the rotor is to the electrode, the greater the suction force is, which makes the rotor in an unstable state. A set of support circuits is used to change the force on the rotor to keep the rotor in the center position. The electrostatic gyroscope uses non-contact support and no friction, so it has high accuracy and a drift rate as low as 10 to 10 degrees/hour. It cannot withstand larger shocks and vibrations. Its disadvantages are complex structure and manufacturing process and high cost.
04 Flexible Gyroscope
A gyroscope with a rotor mounted on an elastic support device. The most widely used flexible gyroscope is the dynamically tuned flexible gyroscope. It consists of an inner flexible rod, an outer flexible rod, a balance ring, a rotor, a drive shaft and a motor. It relies on the dynamic reaction moment (gyroscopic moment) generated during the torsional movement of the balance ring to balance the elastic moment generated by the flexible rod support, thereby making the rotor an unconstrained free rotor. This balance is tuning. The flexible gyroscope is an inertial element that developed rapidly in the 1960s. It has been widely used in aircraft and missiles due to its simple structure, high accuracy (similar to liquid-floating gyroscopes), and low cost.
05 Laser Gyroscope
Its structural principle is completely different from the above gyroscopes. The laser gyroscope is actually a ring laser that does not have a high-speed rotating mechanical rotor, but it uses laser technology to measure the angular velocity of an object relative to inertial space and has the function of a rate gyroscope. The structure and operation of the laser gyroscope are as follows: a triangular cavity is made of materials with extremely small thermal expansion coefficient.
Three reflectors are installed at each vertex of the cavity to form a closed optical path. The cavity is evacuated, filled with helium and neon gas, and equipped with electrodes to form a laser generator. The laser generator produces two laser beams directed in opposite directions. When the ring laser is in a stationary state, the optical path of the two laser beams around the circle is equal, so the frequency is the same, the difference between the two frequencies (frequency difference) is zero, and the interference fringes are zero. When the ring laser rotates around an axis perpendicular to the closed optical path plane, the optical path of the beam of light consistent with the rotation direction is extended, the wavelength increases, and the frequency decreases; the other beam of light is the opposite, so a frequency difference occurs and interference fringes are formed. The number of interference fringes per unit time is proportional to the rotational angular velocity. The drift rate of the laser gyroscope is as low as 0.1 to 0.01 degrees/hour, it is highly reliable and is not affected by linear acceleration, etc. It has been used in the inertial navigation of aircraft and is a promising new gyroscope.