July 12, 2023
The Inertial Navigation System (INS) consists of an Inertial Measurement Unit (IMU) and a Central Processing Unit (CPU), such as a navigation computer on an aircraft. The IMU includes a gyroscope that senses rotation and an accelerometer that measures speed changes. Ring Laser Gyroscope (RLG) and Micro Electro Mechanical System (MEMS) gyroscope are very common types of gyroscopes.
Using the information output by the IMU, the INS can calculate how an object moves in three-dimensional space, its moving direction, and speed. The INS typically fuses data from the Global Satellite Navigation System (GNSS) receiver with IMU data to provide the host computer with information about the absolute position (latitude, longitude, and altitude) and attitude (roll, pitch, and heading) of the platform. The host computer, such as the driverless car, can use this information to complete its driving task.
The combination of IMU and GNSS technology can effectively improve the accuracy of modern navigation systems. GNSS data can compensate for the drift of IMU data due to the accumulation of small errors, thus improving the navigation accuracy.
It is worth noting that INS does not require GNSS or any other external reference to calculate the position or direction of an object. This is particularly important when the GNSS signal is unavailable, shielded, or interrupted, such as when an INS-equipped vehicle travels through a tunnel.
INS is one of the most revolutionary achievements in the history of navigation, freeing pilots from relying on stars, magnetic compasses, and gimbal gyroscopes to fly. Magnetic compasses and gimbal gyroscopes have serious limitations in navigation near the poles. The emergence of INS solutions has provided aircrew with excellent situational awareness and achieved a significant breakthrough.
INS has made continuous progress in the past few decades, making INS solutions smaller and lower in cost, and widely used in various emerging markets that need independent operation.
The performance of INS has been fully proved in a series of aviation applications, and now it has entered the industrial market. Innovative enterprises are applying INS-based technologies to driverless vehicles, manufacturing, robotics, agriculture, transportation, industrial equipment, ocean, mobile mapping, oil and gas, mining, and other fields.
