Working principle of three-axis gyroscope
Three-axis gyroscope is also called micromechanical gyroscope, and micromechanical gyroscope will also be called MEMS gyroscope. Its feature is that it can measure the position of six directions at the same time, and can also measure the moving track and acceleration of these directions. The earliest single-axis gyroscope can only measure in one direction. A three-axis gyroscope can complete the workload of three single-axis gyroscopes. If three gyroscopes are needed in a system, the three-axis gyroscope can perfectly replace three single-axis gyroscopes. Three-axis gyroscope has the advantages of small size, light weight, simple structure and good reliability, which is the development trend of laser gyroscope. In short, the most important function of the three-axis gyroscope is to “measure the angular velocity to judge the motion state of the object, so it is also called a motion sensor.
Application of three-axis gyroscope
The angular velocity sensor and acceleration sensor are not necessarily gyroscopes, but may be simple accelerometers. The core part of the indicator in aircraft, ships or missiles is the directional indicator, which is a small flywheel (gyroscope) installed on a small frame that can turn freely. In this device, the friction moment of the bearing is very small and can be ignored. On the other hand, the rigid body structure is highly symmetrical, and its center of mass is concentrated at the center of the connecting rod. In this way, when the flywheel rotates at high speed around its own axis of symmetry, the spatial orientation of the mandrel remains unchanged regardless of changing the orientation of the frame. (The professional statement is that the external torque of the direction indicator is zero and its angular momentum is conserved) This is an important feature of the direction indicator.
If three orientation indicators are installed on the aircraft and the rotation axes of the three small flywheels are perpendicular to each other, the pilot can determine the spatial orientation of the aircraft by the orientation of the flywheels relative to the fuselage. The ship is equipped with a directional indicator, which can be used by seafarers to determine the course of the ship. Torpedoes and rockets are also equipped with directional indicators to play the role of automatic navigation. During the torpedo’s advance, the axis direction of the orientation indicator remains unchanged. When the torpedo’s forward direction changes due to the influence of wind and waves, there is a deviation between the torpedo’s longitudinal axis and the orientation indicator. At this time, the relevant instruments can be activated to change the rudder angle, so that the torpedo can return to the original forward direction. In the rocket, the flight direction is corrected by changing the jet direction.
The vehicle-grade gyroscope can provide accurate measurement results and greatly improve the dead-reckoning and/or map-matching functions of the vehicle navigator and remote information processing system. In the indoor and high-rise areas with poor GPS satellite signals, the dead reckoning system can compensate for the effect of signal disappearance and replace the satellite to detect the movement and height of objects. The accurate measurement data of the gyroscope can also improve the accuracy of map comparison; Map comparison is the process of describing the movement track of user position observed by satellite or sensor on the road network of digital map. Map comparison is used for various navigation and positioning systems, including traffic flow analysis and vehicle driving direction.
Stephen, the godfather of Apple, was the first to put the three-axis gyroscope into the mobile phone field. Jobs, in 2010, configured the three-axis gyroscope into the iPhone 4 through innovation, which also marked the beginning of mobile phones into smart phones. Three-axis gyroscope is based on the principle of angular momentum conservation by measuring and maintaining the direction of the equipment.
In the following seven or eight years, major mobile phone companies began to equip their products with three-axis gyroscopes, which are now almost standard on mobile phones. Three-axis gyroscopes are used on mobile phones to maintain the stability of some game actions. Many games on the market now need to use this function, such as the recently popular sports shooting games such as survival of the Jedi, action simulation bowling, and so on, as well as in the first-person games such as racing.
Ericco is a manufacturer of navigation and north-seeking MEMS gyroscopes. We provide customized services. If you have requirements or are interested in our products, please feel free to contact us.