Chapter 88: LiDAR Positioning System

The simplest electromagnetic cannon is the electromagnetic railgun. It is mainly composed www.biquge.info of two parallel metal rails and a magnetic field perpendicular to the plane of the metal rail. The shells are also made of metal, which has good electrical conductivity. When fired, the shells were placed on metal rails. And it has good contact with the two-metal guide rail (this is for good conductivity, and if the contact is poor, it will produce a large friction resistance.) ）。 Then, a voltage is added between the two metal rails. In this way, a closed circuit is formed between the two metal rails, the shell, and the power supply. There is an electric current on the shell, and it is in a magnetic field, so it will fly out of the orbit under the action of ampere!

But the electromagnetic railgun also has a very big drawback, that is, the parallel metal guide is easy to be worn out by high-speed moving shells!

So later, scientists developed electromagnetic coil guns, electromagnetic reconnection guns, and electromagnetic fire guns! The performance of these electromagnetic guns is far better than that of electromagnetic railguns!

And it is precisely because of these characteristics of the electromagnetic cannon that the shells of the electromagnetic cannon can be very small. Even a coin can be used as a cannonball for an electromagnetic gun. It may seem incredible, but it's true. If a person can hold two or three shells of ordinary artillery at the same time, then his strength is already very great! But the shells of the electromagnetic cannon, one person can hold thousands or tens of thousands!

One of the reasons why Cheng Xiao chose to install the electromagnetic cannon on the flying eagle is that the cannonball of the electromagnetic cannon is very small, so that the flying eagle does not have to do too much extra work.

Although the mass of the cannonball's shell is small, because it has a lot of speed, it also has a lot of kinetic energy, and its destructive power is also not to be underestimated.

The kinetic energy of a moving object is equal to its mass multiplied by the square of its velocity divided by two. So, mass is not the only factor that determines the kinetic energy of an object.

And some electromagnetic cannon shells can penetrate the earth twelve meters thick. This ability is definitely not comparable to artillery! And the armor of the tank will also be shattered under such a collision!

Although the performance of laser weapons and electromagnetic weapons is superior, they also have their own disadvantages. For example, laser weapons are difficult to attack underwater and underground targets, but electromagnetic guns can easily do it; For missiles moving at high speeds, the electromagnetic cannon sometimes has no way, but the laser cannon doesn't care so much. Because its attack travels at the speed of light, no matter how fast the speed of the missile is, it is impossible to match the speed of light!

Because of this, Cheng Xiao plans to install an electromagnetic cannon and a laser cannon on the flying eagle's body! Let them complement each other.

For the upgraded Flying Eagle, Chengxiao also installed a positioning system for it - LiDAR positioning system!

This positioning system is not used for navigation, but for locating the target object to be attacked by the Flying Eagle's armed defense system!

The hardware of the lidar positioning system is mainly composed of a pulsed laser, a laser receiver, a high-precision angle measuring instrument, and a high-precision timer. Software is a variety of algorithms written by a child.

Because the lidar emits a beam of laser, the coverage range is very limited, so the lidar positioning system can only be used for accurate measurement, and cannot be used alone. But if it has to be used alone, it is also very inefficient.

Therefore, the lidar positioning system needs to be assisted by ordinary radar and other positioning systems before its role can be fully played.

Ordinary radar cannot accurately locate the target object, but the lidar developed by Cheng Xiao can accurately locate it.

For example, after the eagle's ordinary radar, infrared sensors, high-speed cameras and other equipment capture the approximate location of the object, if the eagle wants to strike at the object, the lidar positioning system will be turned on, and the target object will be more accurately positioned and its movement will be more accurately analyzed, and then the data will be transmitted to the computer, and then the computer will control the laser cannon or electromagnetic cannon on the eagle to attack the target object with 100 shots!

Regarding the principle of the lidar positioning system, Cheng Xiao originally conceived it like this:

Take, for example, when the eagle is at rest. If there is a moving object passing by the lidar's coverage at this time, and its approximate position has been determined. Then at a certain time t1, the pulsed laser emits a pulse laser, after the laser hits the object, it is reflected back, and then received by the laser receiver, at the same time, the high-precision timer records the time when the laser is emitted and received, so that the distance between the moving object and the flying eagle can be calculated in combination with the speed of light. The object continues to move, the pulsed laser continuously emits pulsed lasers, and at the t2 moment, the laser hits the object again? is reflected back, and then the distance of the object from the eagle at time t2 is obtained in the same way.

In this process, the high-precision timer records the time difference between time T1 and time T2, and the angle measuring instrument also measures the angle of deflection of the laser head. In this way, several sets of useful data can be obtained.

At this time, the position of the moving object at time T1 is regarded as a point, the position at time T2 is regarded as a point, and the position of the laser head of the pulsed laser is regarded as a point. Three points are connected in pairs to get a triangle. At this time, in this triangle, three of the six conditions are already known, that is, one corner of the two sides (the two sides are measured by a pulsed laser, and the other corner is measured by an angle measuring instrument). According to the cosine theorem in the solution triangle, the side length corresponding to the known angle can be calculated, that is, the displacement of the moving object during that period of time! And because the timer records the time difference between time t1 and time t2, so after knowing the time and the corresponding displacement, the average velocity of the moving object can be calculated using the definition of velocity.

If the lidar measures more than these sets of data, then the acceleration of the object can be calculated using the definition of acceleration.

In addition, the lidar will measure the distance between the moving object and the flying eagle every moment, and if these displacement data are arranged in chronological order, the trajectory of the moving object can be directly drawn! Then, combined with the principles and formulas related to dynamics or directly atmospheric dynamics, the next motion state of the moving object can be analyzed and predicted. In this way, the opponent's movement state is all under his control, so are you afraid of not being able to hit?