Chapter 1166: Response, only Response but No Defense

At the same time that Zheng Guogang was quarreling with the Confucian scholars.

The other side of the world.

The conference hall located in the No. 1 Teaching Building on the Yuquan Campus of Zhejiang University is a busy scene just like before the war.

Zhou Shuwan, who was in a suit and leather shoes, sat at the head of the long conference table, watching with a little emotion as more than a dozen colleagues and students gathered around one person, confirming various details about papers and PPTs.

Just like returning to the scene where he defended his doctorate two years ago——

In fact, during his master's degree, Zhou Shuwan and his mentor have continuously participated in the imitation and improvement of the HTY8 ejection seat and the research and development of the HTY5 ejection seat.

After successfully blogging in 2000, he was very lucky to ride on the rapid development of China's aviation industry.

In just three years, the two main fighter jets, the J-11B and J-10A, have completed high-intensity test flights that lasted as long as the past ten years combined, and were successfully finalized and installed.

This process also provides a large amount of real data for the study of ejection seats and pilot ergonomics.

In the end, both seat models were finalized one step ahead of the aircraft before the end of 2002.

As a result, Zhou Shuwan was able to obtain a doctorate in just two years and enter the 610 Institute of China Aviation Industry Group, which is the Aviation Lifesaving Research Institute.

In actual work, he spends most of his time at the Haofei Group, responsible for seat adaptation work for the new generation of medium bombers currently under development.

As for why he appeared at Zhejiang University... it was largely a coincidence.

Shortly after Zhou Shuwan officially started working, in response to the country’s call to “cultivate world-class high-level engineers,” Zhejiang University first piloted the excellent engineer training program into postgraduate training.

That is to say, graduate tutors and front-line engineers from enterprises serve as tutors to cultivate talents who can solve practical production problems immediately after graduation.

At that time, Zhejiang University happened to be cooperating with Haofei Group to conduct research and development of digital measurement and orbital movement technology.

In short, Zhou Shuwan entered Professor Li Xiongjiang’s research group as an engineer.

And today happens to be the graduation day for the first student he contacted.

Zhou Shuwan also made full use of his contacts and directly invited Chang Hao to participate in the defense.

This is certainly a commendable thing for the entire research team.

Professor Li Xiongjiang posted the defense poster in the most eye-catching location outside the teaching building half a month in advance.

But for graduate students who are just one step away from graduation, the appearance of such a big shot on the defense committee is really not good news.

After all, under normal circumstances, considering the instructor's personal dignity, as long as the thesis itself has been reviewed, the subsequent defense process is almost a formality.

Even if you really only answer and not defend, it is not difficult to successfully obtain a degree.

However, in recent years, there have been a few cases where the defense failed to graduate, and almost all of them were because they aroused doubts from the bosses...

Of course, from another aspect, if you can perform well in the defense process, it is entirely possible to win the favor of a big boss, thereby upgrading the diploma in your hand from a stepping stone to a battering ram...

Therefore, it is not surprising that there would be such a tense and anxious scene...

"Don't all gather around Yang Liang."

Finally, Zhou Shuwan, who couldn't stand it anymore, tapped the table gently, attracting everyone else's attention, and then said:

"People have difficulty breathing when they are stressed, and if you all gather around them, it will only make his mind more confused."

Perhaps in order to improve his persuasiveness, he added an additional sentence at the end:

"This is what Academician Chang told me before."

Sure enough, this sentence is both persuasive and attractive at the same time.

Not only the others, but even Yang Liang himself, who was about to reply, raised his head curiously, with the burning fire of gossip in his eyes.

"Teacher Zhou, I heard that you and Academician Chang... were classmates?"

A junior girl next to her suddenly asked.

In fact, everyone has been curious about these things since Zhou Shuwan joined the research team.

It’s just that I have been suffering from no chance.

"I……"

Faced with the question of which pot should not be opened and which pot should be picked up, Zhou Shuwan's face froze.

However, in the end, he nodded calmly:

"Indeed, we are undergraduate classmates."

After finishing speaking, he continued without waiting for others to speak:

"Actually, he was already working as a professor before I even finished my master's degree... and he was also present when I defended my master's degree, so to be honest, if I were you, I wouldn't be nervous at all... …”

In fact, this is to forcefully change the topic.

Chang Haonan was indeed present when Zhou Shuwan defended his master's degree.

But the problem is that the two people participated in not the same defense at all.

Although it was impossible for Yang Liang opposite to know these details, he couldn't help but rolled his eyes and complained in his heart:

Nonsense, you and he are classmates, of course there is no need to be nervous, but he and I are not...

For a moment, the entire conference room fell into an awkward silence.

Fortunately, after such an interruption, the atmosphere, which had been tense to the point of breaking, finally relaxed a lot.

Especially Yang Liang's mental state seems to have improved a lot...

…

Soon, as other review teachers including Li Xiongjiang arrived one after another, it was finally time for the defense to begin.

A laptop is placed on the desk to share the situation in this conference room in real time——

Chang Haonan was currently in Haojing following up on the research and development of a large bypass ratio turbofan engine, so he could only attend via video.

Fortunately, at the end of 2004, the Internet speed of individual users basically entered the era of Mbps as the unit.

The bandwidth limit for commercial users has also reached double digits with the support of VDSL and other technologies.

It can already support some video conferencing that does not require high image quality.

A few seconds later, Chang Haonan's face appeared on the laptop screen.

It seems that it is also in a certain conference room.

"Academician Chang, we are ready. Do you think we will start immediately?"

Professor Li Xiongjiang asked politely.

Chang Haonan initially agreed to attend, indeed largely because of Zhou Shuwan's face.

But after reading Yang Liang's graduation thesis in detail, I was really interested.

So he nodded and extended his hand in the direction outside the screen:

"Please start the defense, classmate Yang Liang!"

When Chang Haonan called his name directly, Yang Liang, who was already standing behind the small podium, even though he had prepared his mind well, his whole posture suddenly stiffened.

Then he took a deep breath and gently turned the phone back to himself:

"Dear teachers and classmates, I am the respondent Yang Liang. The title of my doctoral thesis is "Application of Digital Measurement and Spatial Positioning Technology in the Automatic Assembly Process of Aircraft". It was written by Professor Li Xiongjiang and Zhou Shuwan Completed under the joint guidance of engineers..."

"First of all, the background of the paper's topic selection. As a strategic industry that promotes the rapid growth of the national economy, the aircraft manufacturing industry directly affects the country's international competitiveness and military deterrence. Aircraft assembly, as an important stage in the entire production process, involves There are a large number of complex components and auxiliary process equipment, and the coordination of each link is complicated..."

Although it is impossible not to be nervous when faced with this kind of posture, after all, he has done real research for four years. Therefore, after actually starting to introduce the contents of the defense, Yang Liang gradually got into the state:

"Our school has cooperated with the Aviation Industry Group Haojing Aircraft Company to develop the first automated spatial positioning and assembly production line in China. However, during the aircraft assembly process, measurements are often impossible due to obstruction by objects..."

"My research content is based on the synergy between multiple laser trackers, using public observation points to transfer the laser trackers, so that aircraft assembly can be carried out under a unified assembly coordinate system..."

"..."

To be honest, even Chang Haonan didn't expect that the Aviation Industry Group next door could advance automated assembly technology so fast after he and Yao Mengna gave it an initial speed.

At the turn of the century, on the eve of the split of the head office, the Haofei Group's method of producing JH-7A was still traditional manual assembly. It was only replaced by mathematical optimization methods in the management process of parts production, work hours and work station allocation. purely empirical method.

In just four years, it has begun to consider introducing automation technology into the spatial positioning and assembly process at the large component level.

If it can be combined with the large-part pre-connection process that he has previously tested on the Falcon 8Z early warning aircraft, then the man-hours occupied in the final assembly process of an aircraft may be reduced to one-fifth or even one-tenth of the current level. Assembly accuracy can actually be improved.

Of course, the current research can only be regarded as the beginning...

Doctoral dissertations are generally long in length, and Yang Liang received guidance from both theory and engineering at the same time, and the amount of content involved was quite exaggerated.

After a full 40 minutes passed, the PPT was finally turned to the last page.

"My defense is over, thank you everyone..."

Looking at the words "Please criticize and correct" on the computer screen in front of him, Yang Liang finally breathed a sigh of relief and stretched out a hand to support the podium to resist the slight dizziness.

However, I dare not take it too lightly.

After finishing the PPT, I just completed the first step of the defense.

The real storm is still waiting behind...

…

After entering the question and answer session, the four defense judges on the scene looked at Chang Haonan on the screen almost simultaneously.

Although the latter is not the chairman of the review committee, from all perspectives, he should definitely be the first to speak.

Facing this scene, Yang Liang also held his breath again...

However, Chang Haonan just waved his hand calmly:

"You should come first, I will ask questions later..."

He didn't even raise his head, but was writing and drawing something on the edge of the paper in front of him——

First of all, with his current status, as long as he speaks, it basically sets the tone for the entire defense, and the people behind him will most likely not have any different opinions.

Secondly, the content of Yang Liang's report just now did give him a lot of inspiration...

Seeing that Chang Haonan was not prepared to express his position, another professor quickly sat up straight:

"You mentioned in your paper that for collaborative measurements between multiple laser trackers, it is necessary to frequently convert the coordinates of the trackers, and you also gave a mathematical model of the station transfer error, but this model is based on It is calculated using public observation points. How do you plan to solve the problem of distribution and error of the observation points themselves? "

Yang Liang forced himself to calm down and think for a few seconds.

Fortunately, this is a tricky angle, but not a difficult one.

"Public observation points are divided into three categories, namely optical tool ball point (OTP), benchmark tool ball point (TBP) and enhanced system reference point (ERS). Among them, OTP and TBP are respectively arranged on the tooling and stable ground. They can As a reference for target ball calibration..."

However, the questions did not end there...

"When the temperature changes at the aircraft assembly site, the thermal expansion characteristics of the tooling and frames in the main dimensions are different due to different materials, shapes and structures. Even the same component may have different expansion characteristics in different directions in space. , and your transfer method involves an expansion of freedom, is it somewhat unreasonable?”

Yang Liang: "This is limited by the current error modeling theory. Too high a degree of freedom will lead to divergence or false convergence of calculation results. And according to simulation tests, the current accuracy can already meet the requirements of existing models. Of course, we The next step of research will focus on solving the problem you raised..."

"You just mentioned the ERS point, but in equation 6-41 on page 97 of your paper, only scaling relative to the center is introduced, that is, only the translation parameter is corrected, although modern aircraft are in most cases The arrangement of ERS points is also symmetrical in theory, but it is obviously impossible to be absolutely accurate in practice, so how are you going to deal with changes in the rotation parameters? "

Yang Liang: "..."

"Classmate Yang Liang, your method uses measured data to optimize calculations, so it will inevitably introduce noise data. How do you plan to remove this interference?"

Yang Liang: "..."

"besides……"

Sweat flowed down.

Not even just Yang Liang.

Even Zhou Shuwan turned his head slightly and looked at the figure on the screen not far away with a slightly pleading look...