The rocket goes up to the sky without getting lost, all thanks to the "magic weapon" guiding the way!

Cars can navigate in cities by relying on landmarks, maps, and satellite navigation, but what do rockets rely on to fly accurately in the air? The famous "inertial navigation" . So the question is, is it because of inertia that rockets use "inertial navigation"?

Can’t tell the difference between “inertial navigation” and “inertia”?

This question is answered by the genius Sir Isaac Newton, who was responsible for much of the brain-burning stuff.

First, please look at my first law. An object will continue to maintain its original state of motion if there is no external force acting on it. This is called "inertia."
Attention! This is an inherent property of an object, which is different from the "habit" you usually talk about.

Inertial navigation is more complicated. It uses inertial sensors (accelerometers and gyroscopes) to measure the acceleration and angular velocity of a moving body, and then calculates its position, speed, attitude and other motion states.

"I guess you haven't understood it yet," Newton wrote F=ma on the blackboard, "The principle is my second law. The acceleration a is the key. It can determine the state of motion of an object (position, speed, etc.), which can be measured by an accelerometer sensor. To determine the state of a moving body in three-dimensional space, it is not enough to know the acceleration a, but also the angular velocity. The sensor that measures angular velocity is called a gyroscope - its invention originated from my research on the mechanics of high-speed rotating rigid bodies." Newton began to summarize: "Gyroscopes and accelerometers are the sensor part of inertial navigation. Because they use the 'inertia' of an object to achieve measurement, they are called inertial devices, and 'inertial navigation' is also named after this." Applause to see off Lord Newton~~~

How is “inertial navigation” achieved?

Inertial navigation technology relies on inertial navigation equipment (INS). The core of common INS is three sets of orthogonally installed gyroscopes and accelerometers, which are used to measure the angular motion and linear motion of the carrier in three-dimensional space.

In addition, the inertial navigation system also has components such as communication, power supply, support, and computing. After power is turned on, the inertial navigation system can continuously measure the angular velocity and acceleration based on the initial motion state, and step by step deduce the attitude, speed, and position at each moment.

For example, suppose you are walking in a maze and you know where you are on the map.

At this time, you are given a magic tool - inertial navigation, which can use accelerometers and gyroscopes to measure the acceleration and angular velocity of your movement, and calculate your current position and direction based on a series of formulas, and can calculate the entire path as you move.

Let me ask you, is inertial navigation awesome? When a rocket is about to enter the big "maze" of space, it is natural to bring along the inertial navigation artifact - it is an important guarantee for achieving high-precision navigation and attitude control, and accurately sending the payload into the predetermined orbit.

According to different mission requirements, there are many types of inertial navigation used in our Long March series of launch vehicles, including dynamic gyro four-axis platform inertial navigation, strapdown inertial navigation, air-floating gyro platform inertial navigation , etc. They each have their own advantages, and the ultimate goal is to enable the rocket to successfully complete the mission. I will not explain them one by one here~

What is the status of “inertial navigation”?

In the navigation industry, inertial navigation can be regarded as a veteran, but its status in the industry remains unshakable. Whether it is satellite navigation or radio navigation, it requires the assistance of external equipment. Even astronomical navigation depends on the "face" of celestial bodies, so they are all subject to "people" at times. Inertial navigation is different. It does not rely on other equipment, is not affected by external interference, does not send signals to the outside, and focuses on "independence" . At the same time, it can also output navigation information continuously and comprehensively, which can be said to be full of skill points. After hundreds of years, from liquid floating gyro inertial navigation to optical gyro inertial navigation to MEMS inertial navigation and atomic gyro inertial navigation, from rockets to airplanes, self-driving cars and even somatosensory game consoles, inertial navigation is still radiating vitality in all aspects of human life.

Rockets use "inertial navigation", although they are indeed "used to it", but it is really because of the "inertia" that Newton talked about. Every time a rocket soars into the sky and accurately enters orbit, it is inseparable from the silent efforts of the inertial navigation equipment. Let us give a thumbs up to the behind-the-scenes hero of inertial navigation!