The military-industrial scientific research system of the academic master.

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

Let's just say, I always felt something was wrong before, but I never really understood it.

Now I finally know what’s wrong——

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

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

As a result, those who didn’t understand originally were just waiting...

Now there's nothing to worry about.

"Mr. Chang...please tell me more specifically?"

Guo Liqiang's tone was much more relaxed than before.

But Chang Haonan did not answer immediately. Instead, he lowered his head and frowned, looking at the white paper in front of him and thinking.

If this state were placed on ordinary people, it would look like they were in a daze.

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

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

It's not easy to disturb him with words.

After a few minutes of brainstorming, Chang Haonan felt a sense 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 to rub his forehead, and looked at Guo Liqiang again:

"Concerning the nonlinear equations generated by multi-station time difference positioning, I can only think of three possible numerical solutions at present."

"?"

How to describe Guo Liqiang's expression at that moment? .

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In fact, when Chang Haonan developed the TORCH Multiphysics software, he systematically studied the solutions to high-order nonlinear partial differential equations.

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

But Guo Liqiang obviously doesn't know this.

He had not participated in the development of TORCH Multiphysics software, and he did not know that Chang Haonan even came up with four solutions to a problem in a shorter period of time when he participated in the design of the die forging press.

So in his opinion, Chang Haonan saw the question he raised, chatted with himself, lowered his head and thought about it, and came up with three ways to solve it.

Is this a person too?

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

He was already used to this kind of expression.

So he immediately said:

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

This explanation obviously cannot completely eliminate the impact of the sentence just now on Guo Liqiang's worldview.

However, at least the latter's expression is no longer as abstract as it was at the beginning.

Seeing this, Chang Haonan didn't waste time and continued what he just said:

"In short, I can't tell you clearly about these three algorithms with paper and pen here, and more importantly, I can't tell you which one is better."

"So it's better to do this. After you go back, first deal with the optimization control problem during the flight of the missile. Our model has a special ballistic trajectory and its range is too far. It is difficult to meet the requirements only by relying on traditional trajectory and turn control rates."

The topic finally returned to an area that Guo Liqiang is familiar with:

"Are you saying that this missile cannot simply follow a high-throwing and diving trajectory during flight, so the missile wings need to provide a greater proportion of lift than ordinary air-to-air missiles in order to maintain the range and trajectory height?"

Chang Haonan turned the report in his hand to a previous page and pointed to the combat schematic diagram drawn by Guo Liqiang:

"Not only that, for the first two detection bombs fired, the trajectory needs to be continuously adjusted in the middle. It is best to shoot a horizontal arc similar to a bracket."

"Also considering that the targets we are currently expected to deal with are large targets with little maneuverability (the only stealth aircraft currently available are F117 and B2), there is no need for the missile to have a very large overload at the end."

"So, in the process of controlling the missile, it is best to tilt the lifting surface to the target direction, and during the tilting process, ensure that the sideslip angle of the yaw channel is as zero as possible, so that the resistance is minimal."

Excluding some of the currently immature gimmicks, the rocket engines of air-to-air missiles are basically the type that are very powerful but of short duration. After the initial acceleration phase is over, the only thing left is to rely on gliding. .

After all, the R33 bomb is large enough and has enough fuel. It relies on slow-burning propellant and relatively low top speed to make it stronger than those thin and short mid-range bombs, but essentially it is still the same.

Therefore, especially in the middle and later stages of the ballistic trajectory, every ounce of energy is very precious and should be wasted as much as possible.

After a short pause, he continued to explain:

"Although trajectory turning control can generally meet this demand, firstly, the response speed is a bit slow, and secondly, when the rotation angular velocity of the target line of sight is very small, the corresponding acceleration command is also very small, and the noise influence in the guidance signal makes it difficult for the missile to move The acceleration vector accurately turns to the optimal orientation, causing the projectile to roll frequently and rapidly, which not only wastes control energy, but also affects the detection accuracy."

"As for the anti-personnel bombs that are actually used to attack the target after follow-up firing, the rapid rolling of the missile in the final guidance stage will cause coupling between the seeker and the missile body, and in severe cases may even lead to complete loss of control. "

After listening to this paragraph, Guo Liqiang did not continue immediately, but let out a weak but meaningful sigh.

Although he couldn't keep up with Chang Haonan's thinking in some places, he was still an expert in the field of guidance and control after all, so he could still understand the issues the latter just mentioned.

However, being able to understand it makes people more concretely aware of how outrageous the person in front of them is——

The few issues Chang Haonan just mentioned are too detailed.

But it's important.

For the average project leader, it is almost impossible to think of these things at the very beginning.

Not to mention it has just started, even in the test firing stage, if the conditions are not stretched enough to the limit, it will not even be discovered.

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

After analyzing the specific cause of the problem, we will come up with solutions and finally go through the test firing process again, which can take as short as a few months or as long as one or two years.

This is not yet a solution. If you think wrong, you have to repeat it again.

But when we arrived at Chang Haonan's place, it only took half a morning to save the above procedures.

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 we consider changing the calculation coordinate system of the aircraft and missiles from self-centered to a unified Haojing 80 or WGS84 coordinate system?"

Those problems just now are largely due to the fact that the entire networking system uses itself as the origin of the coordinate system. In this case, if the missile rolls at high speed, it is equivalent to the coordinate system itself changing at a high speed, and it changes separately. For the target The calculation of position and own flight status is naturally prone to problems.

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

This time, Chang Haonan hesitated.

Technically speaking, Guo Liqiang's idea is feasible.

The only problem is that China does not have almost the entire world’s geographical information data like the United States and the Soviet Union (Russia).

Even some of the marginal data of our own are not complete.

If you do this, your combat efficiency will be greatly reduced once you leave the country.

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

However, it is already September 98.

If nothing else goes wrong, the powder keg of the Balkan Peninsula is about to explode.

Chang Haonan was naturally prepared to let this system go abroad for a "trial trial".

But this kind of thing must not be discussed openly with Guo Liqiang.

Therefore, he needs to organize his language and persuade the other party from another angle.

"Using a unified coordinate system requires both missiles and aircraft to sense their precise location in real time. This is something our country is not currently able to do."

Chang Haonan shook his head:

"I have a better way, which is to directly introduce the sideslip turn mode on the basis of the tilt turn mode, and perform compound control when the missile is about to slide. Take a look..."

"The calculation formula for tilt turn-side slip turn command conversion is n=pn+(1-p)·n..."

"..."

The discussion between the two continued until the afternoon of that day.

Even lunch was specially brought in by Li Rongzai.

"Well, Mr. Guo, this project has been decided for the time being."

Chang Haonan and Guo Liqiang organized the pile of information on the table and put it into their briefcases, and then came to the door together:

"I will contact Director Ding and let you start this project in the name of Thunderbolt 13. After you go back, you will study the composite control first. When I am finished, your Aerospace Technology Research Institute will send it to Torch Group. A tender document will solve the problem of multi-station time difference positioning.”

"no problem."

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

"We have to trouble Mr. Chang a lot more about establishing the project."

"It's nothing, it's just a piece of cake."

Chang Haonan waved his hand:

"In addition, although it is nominally under the name of Thunderbolt 13, I ask you to be prepared."

He used a very rare strong tone:

"This collaborative networked passive positioning system can not only be used on aircraft. Therefore, while receiving R33 technical data to develop air-to-air missiles, we must also work hard on surface-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 Electrical Engineering. When I was working on the JH-7, I found that the hardware conditions there were complete. I would like to slightly change the software and Just a few key parts..."

"..."

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

Whether it's the director of the Science and Technology Commission or the 14th Institute of Electrical Engineering, if anyone says to contact me, just contact me.

This ability to mobilize resources is simply unimaginable...