At that moment, Guo Liqiang's expression was quite exciting.

Let's just say, I always thought something was wrong before, but I never thought too much about it.

Now I finally know what's wrong—

In this exchange just now, he could understand everything Chang Haonan said.

If that's the case, wouldn't his trip be in vain?

As a result, I didn't understand it and waited here......

There's nothing to worry about now.

"Mr. Chang...... Specifically? ”

Guo Liqiang's tone was much more relaxed than just now.

But Chang Haonan didn't answer immediately, but lowered his head and frowned, looked at the white paper in front of him and thought about it.

If this state rests on ordinary people, it looks like they are stunned.

However, this is Chang Haonan after all, so ......

In Guo Liqiang's view, this should be thinking.

It's not easy to bother.

After a few minutes of brainstorming, Chang Haonan felt a feeling of dizziness for the first time.

It seems that it is a bit too whimsical to skip supercomputing and use the human brain to simulate numerical calculation results.

So he raised his head, raised his hand and rubbed the corners of his forehead, and looked at Guo Liqiang again:

"With regard to the system of nonlinear equations generated by multi-station time-lag positioning, I have only thought of three possible numerical solutions"

“？”

At that moment, how should Guo Liqiang's expression be described? .

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In fact, when Chang Haonan developed the TORCH Multiphysics software, he systematically studied the solution of higher-order nonlinear partial differential equations.

Although the software itself has been tried for about a year, and it is estimated that the official version will be released in a while, he has not stopped researching this direction.

But Guo Liqiang obviously doesn't know this.

He did not participate in the development of the TORCH Multiphysics software, nor did he know that Chang Haonan participated in the design of the die forging press, and even came up with four solutions to a problem in a shorter period of time.

So in his opinion, Chang Haonan saw the question he raised, then chatted with himself, lowered his head and thought about it, and came up with a solution, and there are three kinds of solutions.

Is this also personal?

Chang Haonan felt that the atmosphere behind him was a little wrong, so he turned his head and saw Guo Liqiang with a stunned face.

He was used to this kind of expression.

So he immediately spoke:

"When I was working on a project before, I studied similar problems by the way, and I just deduced the conclusion a little."

Obviously, this explanation cannot completely eliminate the blow to Guo Liqiang's worldview just now.

However, at least the latter's expression is not as abstract as it was at the beginning.

Seeing this, Chang Haonan did not waste time and continued along the content just now:

"In short, these three algorithms, I must not be able to tell you clearly with pen and paper here, and more importantly, I can't say which one is better."

"So it's better to do this, after you go back, first deal with the problem of optimal control during the flight of the missile, our model has a special trajectory, and the range is too far, and it is difficult to meet the requirements only by relying on the traditional trajectory turning control rate."

The topic finally returned to the field that Guo Liqiang is more familiar with:

"Do you mean that this missile cannot simply go high and dive into a trajectory during flight, so it needs to be provided by the wings to provide a greater proportion of lift than ordinary air-to-air missiles in order to maintain its range and ballistic altitude?"

Chang Haonan turned the report in his hand to a certain page in front of him, and pointed to the operational schematic diagram drawn by Guo Liqiang on it:

"Not only that, for the first two detection missiles that are fired, the trajectory of the ballistic needs to be continuously adjusted in the middle, and it is best to make a horizontal arc similar to brackets."

"Considering that the targets we expect to deal with at the moment are large targets with little maneuverability (the only stealth aircraft at this time are F117 and B2), so we don't need a very large overload of missiles at the end."

"Therefore, in the process of controlling the missile, it is best to tilt the lift surface to the target azimuth, and in the process of inclination, it is necessary to ensure that the yaw channel sideslip angle is as zero as possible, so that the resistance is minimal."

Excluding some of the tricks that are not yet mature, the rocket engines of air-to-air missiles are basically the type with great power but short duration, and after the initial acceleration phase is over, the rest can only rely on gliding.

After all, the R33 bomb is large enough and fuel, and it can be stiffer than those thin and short medium-range bombs with slow-burning propellant and relatively low top speed, but it is still the same in essence.

Therefore, especially in the middle and rear stages of the trajectory, every trace of energy is very precious, and it can be wasted as much as possible.

After a pause, he continued:

"Although the trajectory turning control can generally meet this demand, the first is that the response speed is a little slow, the second is that the angular velocity of rotation in the target line of sight is very small, and the corresponding acceleration command is also very small, and the noise influence in the guidance signal makes it difficult for the missile body to accurately turn the acceleration vector to the optimal orientation, resulting in frequent and rapid rolling of the projectile body, not to mention the waste of control energy, and it will also affect the detection accuracy."

"For the anti-personnel missiles that are really used to attack the target, the rapid rolling of the missile in the final guidance stage will cause the coupling of the seeker and the missile body, and in serious cases, it will even lead to a complete loss of control."

After listening to this paragraph, Guo Liqiang did not immediately continue along the conversation, but let out a faint, but meaningful sigh.

Although he can't keep up with Chang Haonan's train of thought in some places, after all, he is also an expert in the field of guidance and control, and he can still understand the problem that the latter just said.

However, being able to understand it makes people more specifically perceive how rebellious the person in front of them is-

Just a few questions that Chang Haonan said just now are too detailed.

But it's important.

It's almost impossible for the average project leader to think of this at the beginning.

Not to mention that it has just begun, even if it reaches the test launch stage, if the conditions are not stretched to the limit enough, it will not even be discovered.

Therefore, it must not be discovered until the end of the test firing.

Wait until the specific cause of the problem is analyzed, and then think of a solution, and finally go through a new round of test launch process, which can be as short as a few months, or as long as a year or two.

That's not all, if the idea is wrong, then you have to repeat it again.

And when I arrived at Chang Haonan, it only took half a morning to save the above processes.

The time and money saved can be said to be immeasurable......

While sighing in his heart, Guo Liqiang was not completely stunned, but quickly thought of an idea:

"Can you consider changing the calculation coordinate system of the carrier aircraft and missiles from self-centered to a unified Hokyo-80 or WGS84 coordinate system?"

In this case, if the missile rolls at high speed, it is equivalent to the coordinate system itself changing at high speed, and it is also changing separately, and the calculation of the target position and its own flight state is naturally prone to problems.

If you change to a unified coordinate system, the problem can be alleviated a lot.

This time, Chang Haonan hesitated.

Technically, Guo Liqiang's idea is feasible.

The only problem is that China does not have access to almost the world's geographic information data like the United States and the Soviet Union (Russia).

Not even some of the data in the corners of the house.

If this is done, once you go abroad, your combat efficiency will be greatly reduced.

Of course, as far as the current operational needs of the Air Force are concerned, it is sufficient.

However, it is now September '98.

If nothing else, the powder keg of the Balkans is about to explode.

Chang Haonan is naturally ready to let this system go abroad to "try" it.

But this kind of thing must not be told to Guo Liqiangming.

Therefore, he needs to organize the language and convince the other party from a different angle.

"If we use a unified coordinate system, we need both missiles and aircraft to be able to perceive their precise location in real time, which our country cannot do at present."

Chang Haonan shook his head:

"I have a better way, which is to introduce a sideslip turn mode directly on the basis of the tilt turn mode, and carry out compound control when the missile is about to slip, you can see ......"

"The formula for calculating the conversion of inclined turn-sideslip turn instruction is n=ρn+(1-ρ)·n......"

“……”

The discussion continued into the afternoon.

Even the lunch was specially brought in by Li Rongzai.

"Then Guo Gong, the matter of this project is so decided for the time being."

Chang Haonan and Guo Liqiang sorted out the large pile of materials on the table and put them in their briefcases, and came to the door together:

"I will contact Director Ding, let you start this project in the name of Thunderbolt 13, and after you go back, you will first study the matter of composite control, and when I am done here, your Aerospace Technology Research Institute will send a tender to the Torch Group to solve the problem of multi-station jet lag."

"No problem."

The latter nodded, and held Chang Haonan's hand excitedly with both hands:

"In the matter of setting up the project, I have to work hard."

"It's nothing, it's just a gesture."

Chang Haonan waved his hand:

"Also, although it is nominally under the name of Thunderbolt 13, I ask you to prepare for both."

He used a rather unusually tough tone:

"This collaborative networking passive positioning system can not only be used in aircraft. Therefore, while receiving R33 technical data and engaging in air-to-air missiles, it is also necessary to work ground-to-air or ship-to-air missiles. ”

"As for the land-based or sea-based passive positioning radar, I will contact the 14th Institute of the Electric Science and Technology Department, when I was working on the J-7 before, I found that the hardware conditions over there are complete, just change the software and some key parts a little......

“……”

Guo Liqiang didn't expect that he would be shocked by Chang Haonan once before he left.

Whether it is the director of the Commission of Science and Technology or the 14 institutes of electrical technology, people will contact each other when they say they will contact it.

The ability to mobilize resources is unimaginable......

(End of chapter)