Chapter 303: Is the distance measurement accurate?
Although Mr. He looks like a rough guy, he is very smart. As soon as he heard Gao Zhendong's words, he immediately reacted, hehe, there is something going on.
"Director Gao! Vice President Gao! Stop showing off. I'll do whatever you say. I'll fight wherever you point me. What good things are there to take care of us?"
Also Not to mention, although the person who first met Gao Zhendong was Mr. Guan in charge of armor, but compared to the number of good things he got from Gao Zhendong, it was undoubtedly Comrade Lao He who was in charge of firepower.
Tail-stabilized discarding sabots, ESR gun steel, self-tightening barrels, and stable weapons. No way, Gao Zhendong’s phobia of lack of firepower is also in the advanced stage, because he was personally suppressed by enemy firepower on the battlefield. of.
Therefore, this disease cannot be cured at an advanced stage and can only be treated conservatively.
Of the conservative treatment prescriptions, the most effective one is undoubtedly to fight poison with poison.
As the saying goes, "If you are poor, you will be interspersed with tactics; if you are great, you will be bombed by me."
So it is not surprising that Lao He got more good stuff from Gao Zhendong. He said that he was a "direct force", which was just a joke, but it was not entirely unreasonable.
Gao Zhendong first asked a question: "What is the biggest problem you encounter in the process of fire control?"
Lao He didn't hesitate at all. He had turned this problem over in his head countless times and thought of countless ways to solve it.
"Distance! It must be distance!"
Without knowing the distance, no matter how good the ballistic performance of the artillery shell is, the fire control will not work.
The difference between tanks and infantry is that the effective engagement distance of infantry is about 400 meters. In this range, it can be visually estimated and can be used to set the sight ruler, but tanks are more than 1,000 meters away. The combat distance cannot be estimated accurately at all.
Most of the sights at this time used optical ranging. The name is very nice, but it is actually an estimate. It is only through technical means that the estimate can be more accurate, but how many Accurate, actually not so much.
A typical optical distance measurement method is reticle distance measurement. The distance measurement curve in the sight is used to set the target. Since the height or length of the target is relatively typical, for example, a person is calculated as 1.7 meters long and a tank is 8 meters long. , so that when the target is exactly the same height or width as the curve, the corresponding distance value on the curve is the target distance.
Needless to say, the accuracy of this method, the inconsistency of the target, the inaccuracy of human eye readings, the roughness of the distance measurement marks, etc., all determine that this method is only a rough measurement.
After hearing Mr. He's answer, Gao Zhendong, who had expected it, asked with a smile: "Is it an optical distance measurement? Is the measurement accurate?"
These words immediately gave Mr. He a Qian was silent and shook his head: "To be honest, it is not accurate, and it is greatly affected by the proficiency of the personnel. In actual use, an error of more than 10% is not uncommon at all. Vice President Gao, are you planning to improve the test?" Distance equipment? Use this DJS-60D?”
Gao Zhendong shook his head: “You’re right, I’m going to improve the distance measurement method.”
Mr. He was very happy when he heard this: "Great, this thing has been bothering us for a long time. It's not that it can't be used now, and the troops didn't give much advice, but we know in our hearts that this thing is not very accurate, especially It’s under long distances and complex weather conditions.”
The reason why the troops didn’t comment too much is because they haven’t seen anything better.
An inch is long and an inch is strong. Even if you have a good cannon, it is useless if you cannot hit it from a long distance. You still have to fight the enemy with a bayonet when you are close to the enemy. Then half of the meaning of a good cannon is lost. After all, the distance is close. Even if the power of other people's cannons is average, the threat has increased a lot.
Gao Zhendong asked: "Have you done any preliminary work? Tell me about it."
When it comes to business, Mr. He can get serious.
"We first considered radar, but after communicating with comrades who work on radar, radar is fine in the sky, but it can't handle the clutter problem on the ground, and the lobe is too wide, so we don't know where we are measuring in front of us. A thing. "
The radar technology at this time is probably like this and cannot support this demand at all.
“We have also thought about infrared rays, ultrasonic waves, etc., but problems such as poor directivity, insufficient power, and susceptibility to interference cannot be solved. In short, it still doesn’t work.”
高Zhendong smiled and said: "Have you ever considered a new technology, laser?"
Mr. He's eyes lit up, then darkened quickly: "I have considered it. I considered it when laser first came out. But there are many problems.”
Gao Zhendong said: "Let's talk about it, let's see if we can solve it."
For this, Mr. He didn't have much hope. After all, lasers are too new. But after all, Vice President Gao's brain is comparable to mine. Let's talk about it, there may be hope.
“Putting aside all the troubles in theory and practical engineering applications, the first problem is that light runs too fast. We have not found a fast enough timing method to calculate how far it has traveled. A long time. We have calculated that if we want to achieve a measurement accuracy of 1 meter, we need a circuit that operates at a frequency of at least 150MHz. We do not have such a fast oscillator, and the reliable ones we have are only around 10MHz.”
The laser rangefinder does not need a computer as a controller and converter, but it needs at least a short enough time as a benchmark to measure the flight time of light. Of course, there is also a method that does not count time, but that method is not suitable for use on tank laser rangefinders.
The oscillator may not seem like an inconspicuous thing, but it provides the most basic working rhythm for basically all digital circuits: pulse. In the future, what is the main frequency of the CPU that everyone often talks about? In fact, this is what I'm talking about, it determines the working speed of digital circuits. Regardless of whether there will be GHz or THz in the future, those that provide the most basic oscillations, such as crystal oscillators, are generally below 100MHz. As for such high operating frequencies, other technical means are used to achieve this oscillation.
At this time in China in 1960, oscillators above 100MHz were relatively vague.
Seeing that Gao Zhendong did not interrupt or ask questions, knowing that Gao Zhendong could understand these things, he continued.
“It is not impossible to achieve this frequency using other means, but we have communicated with comrades who are engaged in electronics, such as multi-stage series second harmonic circuits, third harmonic circuits, etc., but it doesn’t work that way. The pulse is uneven, so it’s meaningless to measure the error.”
After hearing this, Gao Zhendong didn’t say anything more. He only said something that made Mr. He overjoyed: “I’ll solve this problem for you.” You continued. Something else.”
The reason why Gao Zhendong said this is that he knows how to solve this problem, and the answer is ready.
——Phase locked loop circuit, PLL.
The multi-frequency circuit composed of phase-locked loops is typically characterized by high precision and very stable output. It is widely used in communication, measurement and other circuits.
As for phase-locked loop circuits, although digital phase-locked loop integrated circuit chips will be common in the future, discrete components are directly built into the phase-locked loop circuit. Gao Zhendong happened to do it when he was working on a project with his tutor in his junior year. Pass.
Thanks to his brain, he remembers very clearly that although the working conditions, parameters, and components are different, the circuit can be changed.
Unexpectedly, Vice President Gao solved the first problem clearly. Mr. He rubbed his hands in excitement: "Thank you, Vice President Gao, thank you, thank you."
It feels like happiness comes too suddenly, and my head can't turn around at once.
Several other comrades who came together looked at Gao Zhendong’s calm expression, and then thought about the difficulty of the problem he solved, they could only lament in their hearts that the gap between this person and others was too great. It's big.
While Gao Zhendong wrote down this matter on paper, he said: "If you have any questions, continue."
Mr. He thought for a while: "The second one is, this laser The technology is so new that we know nothing about all its technical principles, application methods, and test methods. I bought the first issue of the "Laser" journal, but I don't understand it very well."
Gao Zhendong smiled: "This is why I asked you to stay for a while. I will teach you about laser-related knowledge."
The comrades at the Prairie Tractor Factory felt like they had found an organization. He came up. The senior vice president was young and he really came up when something happened.
Mr. He was a little hesitant. It wasn’t that he didn’t believe in Gao Zhendong’s ability, but he was worried about something else: “Vice President Gao, you take time to learn about lasers and then teach us, right? Is it a waste of your time?”
He knows that Vice President Gao has a lot of work. For their project, it would be a waste of time to learn laser-related things and then teach them. It's too big, and he can't bear it.
Gao Zhendong looked confused: "Learn? I don't need to learn."
"Ah, Vice President Gao has already learned it?"
Gao Zhendong looked at Mr. He with an expression of "don't you know?": "I was the one who made the laser, if nothing else, It’s okay to teach you.”
This was quite “modest”, but he forgot that people really don’t know.
Mr. He:? ~~~! ! ! !
Others:! ! ! ! ! ! !
Lao He suddenly had the urge to open Gao Zhendong's brain and see how he grew.
"Vice President Gao, this is really beyond our expectation. Hey, I didn't expect that there is such a giant Buddha among the people I know, hehe."
As for lasers, although they don't I understand, but I can still understand the various praises in the reports. Apart from that, the words "No. 1 in the world" can explain all the problems.
Gao Zhendong waved his hand: "It's not that exaggerated, haha, I'm just lucky and it goes smoothly."
Vice President Gao, if you don't know how to be humble, you don't have to be humble.
"Are there any other problems?"
"It's gone, no, it's not gone, it's just that it hasn't been discovered yet. After all, I haven't learned the principles yet, and I haven't been able to find the problem yet." Mr. He was very bachelor. I won't, I don't.
(End of this chapter)