Significance and Working of Gyroscopes
Gyroscopes are an important part of any internal guidance or navigation system of aircraft. Despite being invented over a century ago, they remain in use to this day. A gyroscope is a device that uses the Earth’s gravity to measure or maintain orientation and angular velocity. The configuration features a spinning wheel or disc in which the axis of rotation is free to take on any orientation. While in rotation, the orientation of this axis is not affected by titling or rotation of the mounting. Gyroscopes have applications throughout the aerospace, aviation, marine, and defense industries. They guide ballistic missiles and satellites, aid in the building of tunnels, and work in ship gun fire control systems.
The first gyroscope consisted of a simple spinning wheel or disc which worked on the principle of angular momentum. As technology evolved, more configurations were developed to increase accuracy and consistency of output. There are currently three commonly used types of gyroscopes: Ring Laser (RLG) & Fiber Optics Gyroscopes (FOG), Dynamically Tuned Gyroscopes (DTG), and MEMS Gyroscopes. RLG and FOG both operate on the Sagnac effect, a principle which, in simplest terms, states that a beam of light split in two halves traveling in opposite directions will experience phase changes when the apparatus is acted on by angular velocity. Instead of a light, RLGs use a laser and by analyzing the phase changes during rotation, users can measure the angular velocity. RLGs are found in inertial navigation systems of military aircraft, commercial airliners, ships, and spacecraft.
FOGs also use the Sagnac effect, but increase the effect by using multiple coils for the light to travel through. The phase changes are multiplied by each additional coil that the FOG employs. This provides increased sensitivity and generally more accuracy than the RLG. FLGs have many applications such as high-performance space applications, fiber optic gyrocompasses in navigation systems, guiding systems for ballistic missiles, autonomous underwater vehicles, and surveying equipment. The main benefits of FOGs are their extreme precision, lack of moving parts, higher resolution, and that they do not rely on inertial resistance in order to function. Unfortunately, they have longer production times due to their calibration requirements and can only be used for a single axis.
Dynamically Tuned Gyroscopes, or DTGs, are mechanical. They contain a rotor that is held between two pivots. At a given speed known as tuning speed, the rotor is free from torque. For this reason, DTGs can be used as a conventional or ideal gyroscope, most commonly to measure rotational displacement from gimbal. MEMS (microelectromechanical system) gyroscopes use a vibrating element for rate measurement. They operated on the principle that a vibrating element will continue vibrating in its plane of vibration. Consequently, if the orientation of the platform on which an element sits is vibrating, the element will exert a force on the platform. This force is then measured to find the output. Some of the benefits of MEMS gyroscopes are that they are much smaller than other types, can be integrated with a digital interface, are less power-consuming, and cost significantly less than FOG and RLG gyroscopes, making them more widely available to the mass market.
Share
Semiconductor's Certifications and Memberships
