Chapter 211 It has to be Director Gao! (3k)

On Wednesday, Gao Zhendong was revising his thesis when Yu Yuncheng came over and said, "Director Gao, we decided to take advantage of your help today and try to make a ruby ​​single crystal. Can you come and take charge?"

Gao Zhendong put away his pen and said, "Come on, I'll go take a look."

It seems that Yu Yuncheng realized that the ruby ​​was very important to Gao Zhendong's work and sped up the progress.

The two came to the single crystal furnace laboratory. All the preparations had been completed. The alumina powder was piled into a steamed bun shape in the single crystal furnace.

People connected two lines from the computer room, one for the monitor and the other for the keyboard. In this laboratory, only Gao Zhendong's DJS-59 monitor and keyboard were there.

Although the distance is relatively long, fortunately the signal level of the equipment is relatively high at this time, so it works normally.

The program on the screen was written by Gao Zhendong, and he was very familiar with the interface.

Different from the graphical instruments on the interfaces of future configuration software and industrial control software, this control program adopts the form of rolling output parameters in order to save resources, which requires a slightly higher degree of concentration from the staff.

Although Gao Zhendong was not very satisfied with this, Yu Yuncheng and others thought it was very good. A few months ago, they would never have dared to imagine that they would be able to use this thing.

"Director Gao, you start." Yu Yuncheng said with a smile.

Gao Zhendong did not refuse and gave the start command: "Melt!"

The members of the research team pressed the power switch, and with a "buzzing" sound of electricity, heat waves gradually emanated from the single crystal furnace body.

This process is long and takes one to two hours.

During the process, Yu Yuncheng kept giving instructions.

“Pay attention to the vacuum.”

"What's the temperature of the oven?"

"The vacuum degree is about to exceed the standard, stop heating." Although there is a computer in automatic control, Yu Yuncheng still couldn't help but remind the test personnel. After all, the reliability of machinery and equipment these days is not that good, and necessary human intervention or monitoring is still necessary.

Machines ensure control accuracy, and manual labor ensures reliability.

The method is crude, but it works.

"The melt is almost done. Lower the temperature, raise the crucible, and reduce the power to the seeding power."

The power of seeding is smaller than that of melting material, otherwise the fluidity of the molten material will be too strong and it cannot be seeded.

The specific value of the seeding power is different for different materials. We first calculate it based on the thermal field and crystal formation experience and theory given by Gao Zhendong to get a relatively small range, and then gradually test the most suitable specific value within this range.

In their previous work, Yu Yuncheng and his colleagues have already tested out this appropriate value for aluminum oxide.

"Okay, raise the pot to the seeding position, lower the seed crystal, pass argon gas, pressure 0.Xkg."

The seed crystal that had been clamped in place was lowered to a few millimeters above the liquid level in the crucible under the control of the seed crystal arm.

"Sowing seeds!"

"The temperature is OK, let's seed the crystal."

In order to achieve this accurate seeding temperature, Yu Yuncheng even used two cut seed crystals in previous experiments.

"Neck."

"Let go of your shoulders. Okay, warm up."

"The diameter is reached, turn the shoulders, and pull the crystal."

Following Yu Yuncheng's command, the seed crystal arm began to slowly rotate and lift, and a cylinder emitting incandescent light slowly took shape.

It’s not that Yu Yuncheng wants to be a conspicuous person and steal the computer’s work, but many of the initial steps require human eyes and experience, and computers and control systems cannot do this job.

Or to put it another way, at this time, the computer can help control various parameters more accurately, but it cannot make decisions on a considerable part of the nodes in the process and can only execute. The decision-makers still have to be people.

The crystal begins to grow to a medium diameter during the rotation and pulling process. During the growth process, the diameter control also relies on human decision-making and computer execution of process control.

The length is almost 10 centimeters. If it is pulled any further, problems such as polycrystalline and dislocation will appear.

Yu Yuncheng began to ask the staff to finish up.

As the slender tail of the single crystal slowly left the liquid surface, Yu Yuncheng gave the order to stop the furnace.

The shutdown instruction sounds simple, but it actually includes a series of actions such as shutting down the heating power, shutting down the atmosphere protection, shutting down the vacuum system, etc.

After a busy and orderly process, the first step of the entire experiment was completed.

The rest is to wait for it to cool down for an hour or two before sending it for inspection. Although the results are not known yet, at least the whole process went smoothly.

Gao Zhendong smiled at Yu Yuncheng and said, "It looks good. At least there was no accident."

This was not Gao Zhendong's flattery for no apparent reason. The entire experimental process seemed to be under the control of the research team, and nothing unexpected happened. For a preliminary test, it was actually a success.

Yu Yuncheng wiped his sweat. Although Gao Zhendong designed a camera facing the observation window for easy observation, the performance of cameras at that time was quite average.

In order to ensure the safety of the equipment, he would often go to the observation window to check, and it would not be an exaggeration to say that the heat there was overwhelming.

Yu Yuncheng was also very excited. The smooth completion of the test process was a good sign: "Well, it seems that asking Director Gao to take charge was the right decision, haha."

If you want to praise someone, then praise him/her hard.

The experimenters around were all very happy. The experiment went smoothly and they were naturally in a good mood. After listening to Yu Yuncheng's words, they all felt a little like the feeling in later skits, "I didn't expect that you, with thick eyebrows and big eyes, could do it too", and they were even happier.

While laughing, Gao Zhendong carefully recalled the entire experimental process and suddenly thought of a question.

"Mr. Yu, I have a question."

Yu Yuncheng was delighted. It was a good thing that Director Gao could see the problem. This meant that the process could be optimized a little more. "Director Gao, you tell me."

"I see that some of your other important process nodes currently rely on manual judgment and decision-making, which is normal because the indicators are unclear and the sensor capabilities are limited, making it difficult for machines to make decisions. But is the diameter growth stage also being manually decided and controlled? In theory, the diameter indicator is relatively clear and accurate."

Yu Yuncheng touched his head and said, "Director Gao, you finally hit the nail on the head. I am also struggling with this matter."

"You say the diameter is clear, and it is. But there is a problem. The machine cannot know whether the diameter of the crystal in the furnace has reached the set value. The human eye can tell whether the diameter is roughly the same, but the machine cannot."

"The machine doesn't work?" Gao Zhendong frowned. There was a little trouble.

"Yes, we can't get a ruler into the furnace to measure. Let's not talk about the temperature issue. Once the ruler goes in, it will theoretically contaminate the raw materials. Even if it is cleaned thoroughly, the ruler needs to touch the crystal to measure. Once it touches the crystal, everything will be ruined."

Gao Zhendong thought about it and realized that this was indeed the problem he was talking about. To put it bluntly, this was a classic fuzzy control problem. The current control system is very powerless when it comes to things that are too complex or difficult to describe accurately.

No matter how large the diameter needs to be controlled, it is very clear, and the thickness of the crystal can be seen with the naked eye.

However, unlike humans, machines are invisible, and there is no suitable means to measure the specific diameter data of the crystal.

It's like whether clothes are dirty or not. People can tell at a glance, but for machines without fuzzy control capabilities, it is difficult to judge. It has to detect various relevant data on the clothes to make a judgment.

This is not for the future. In the future, a camera will only need to draw a detection line within the camera's surveillance screen, and there will not even be a need to use gimmicks like AI.

But the cameras at that time did not have this capability. This thing was purely analog, and even things like video servers did not exist.

Gao Zhendong glanced at the camera, then at the surveillance screen, and suddenly an idea flashed in his mind.

Pull the test line? Got it!
There are no video tools in the video server, but I have my own way! What Gao Zhendong didn't know at this time was that this method he thought of was originally one of the means of diameter control in the future when technology was not so advanced.

Gao Zhendong laughed: "There is a way!"

Yu Yuncheng and others were delighted when they heard this. This equal diameter control is one of the most labor-intensive, but very critical steps in the entire crystal pulling process.

Even for the first few important nodes, the node time is actually relatively short, but the equal diameter control must be monitored from the beginning of shoulder turning to the end.

But judging from the conditions, it seems that it has the greatest hope of solving the problem of transitioning from manual to automatic, which makes people feel very regretful.

When everyone heard that Gao Zhendong had a solution, they became excited. It had to be Director Gao.

You guys can solve the small problems, and I will take care of the overall theoretical, design and technical difficulties!

Everyone looked at Gao Zhendong to see what ideas he had.

Gao Zhendong walked to the monitor of the camera and said with a smile: "From this monitor, we can see the diameter of the crystal, right?"

Everyone nodded. Although the camera effect was very average at that time, the image with clear boundaries was still very clear. Usually they mainly carried out equal diameter control by observing the monitor.

"But even though we can see it, the surveillance camera itself doesn't know it." Someone immediately raised his doubts.

Gao Zhendong smiled and said, "Then we will install an eye on the monitor."

"Eyes?" No one knew what Gao Zhendong was talking about. Install another camera to stare at this monitor?
Gao Zhendong pointed at the picture on the monitor and said, "Isn't it that the crystal part of the picture is dark, while the picture around the crystal is very bright because of the light emitted by the melt itself?"

Yu Yuncheng nodded: "Yes, the boundary between the two is very clear, one is light and the other is dark, or even one can say one is black and the other is white."

Gao Zhendong smiled and said, "Then let's install a photosensitive element on this monitor."

Before he could finish his words, Yu Yuncheng, who was not an expert in automation, had not figured it out yet, but there was a professional in this field among the test personnel who suddenly realized it.

(End of this chapter)