I can become stronger by paying salaries. I have one billion employees!

Chapter 650 The technical challenges of the dual-core mask stage? Break it! Zhang Yanjie: The more you understand, the more you respect it!
At dawn the next day, Chen Yansen slowly opened his eyes.

Ye Qiuping lay beside him, her breathing even and deep. Beneath her semi-transparent silk nightgown, her curves were faintly visible, revealing her formidable physique.

Chen Yansen lifted the corner of the quilt, put on his slippers, and went outside.

A cosplay outfit of Slow Sheep and Green Snake was casually tossed on the floor, with a moving tail next to it.

Entering his study, he turned on his computer and, as usual, first checked the core operating indicators of each subsidiary. Only after confirming that there were no problems did he begin to process emails.

With his memory and comprehension, even if it's an email with thousands of words, he can usually memorize all the contents with just a glance and give a precise, professional, and mature reply in just a few seconds.

Therefore, he finished his work in less than ten minutes.

A "buzz" sound!
The phone on the table vibrated.

Chen Yansen picked it up and saw that it was a message from Song Yuncheng. After a moment's thought, he replied with a "Okay".

At 8:50 a.m., he arrived at the Optical Research and Development Center on time, held a brief meeting with the algorithm team members, and then got down to work.

The ultra-precision motion control technology of the mask stage requires motion control algorithms and software with nanometer-level precision.

After thoroughly understanding the core of the technology, Chen Yansen designed a composite control architecture, which adopts a three-layer structure of "feedforward + feedback + disturbance compensation".

First, based on the acceleration feedforward and friction feedforward of the motion trajectory, the system lag is compensated.

In layman's terms, it means anticipating problems in advance and taking proactive measures!

Just like an experienced driver who sees a slope ahead and accelerates in advance, instead of waiting for the car to slow down before reacting.

Acceleration feedforward means that, based on a pre-planned route, such as how much to accelerate and when to decelerate, the motor is given a "command" in advance so that it exerts force when it should, thus avoiding lag in action.

Friction feedforward, on the other hand, assumes that since friction will occur between parts when the machine is running, similar to the resistance between a tire and the ground, the additional force required to overcome this friction is calculated in advance, thereby ensuring the accuracy of the machine's movements.

Secondly, a hybrid control method combining PID and LQR is used.

In other words, it means making real-time corrections and adjusting while keeping an eye on the target.

It's like watching the dashboard while driving; if you notice the speed is too fast, you ease off the accelerator, and if it's too slow, you press it a little to correct any deviations.

PID is one of the most commonly used control algorithms in industrial control. Simply put, it is a set of rules that "adjust actions based on errors" to keep the equipment's operating state stable at the target value.

LQR, or Linear Quadratic Regulator, is a more intelligent automatic control algorithm.

Taking the precise stopping of a robotic arm at a designated position as an example, ordinary control methods can only make adjustments by closely monitoring the "deviation between the current position and the target position".

LQR can take into account multiple factors at the same time, such as how much the current position has deviated, whether the moving speed is appropriate, the magnitude of the torque output by the motor, and whether the parts will shake due to excessive force.

Once this technology is broken through to the nanoscale, it can be used not only for the manufacture of masking stages, but also for applications such as robot motion control and satellite attitude adjustment.

Finally, there is the disturbance compensation technique, which estimates the value of external disturbances through an extended Kalman filter and cancels them in real time.

Just like when a gust of wind suddenly blows while driving, the steering wheel will shake, and the driver needs to make immediate adjustments to stabilize the direction.

An extended Kalman filter is like a combination of a "sensitive sensor and a high-efficiency calculator". It can quickly detect sudden external interference and then immediately calculate the force compensation to counteract the effects of these interferences and ensure that the accuracy is not affected.

When these three methods are used in combination, the entire control logic is like a super driver who is good at prediction, proficient in fine adjustment and has excellent anti-interference ability. It can make the machine move quickly and accurately, and can also deal with various small interferences, keeping the precision stable at the nanometer level.

In fact, many universities and research institutes in China, such as Harbin Institute of Technology, Tsinghua University, and the Institute of Automation of Huazhong University of Science and Technology, have conducted in-depth research on classic control algorithms such as PID, LQR, and Kalman filtering, and have published a large number of related papers.

Most current algorithms have only completed simulations or small-scale experiments and have not yet undergone application-level verification on high-precision motion platforms.

There is a serious lack of experience in matching theoretical models with actual mechanical nonlinearity!

Furthermore, in terms of compensation for friction and gaps, it can currently only be achieved at the micrometer level.

The main reason that hinders the rapid breakthrough of this technology is that the localization rate of key supporting products such as precision bearings, air-bearing components, and high-stability power supplies is too low, and their performance is significantly different from that of foreign products. This makes it extremely difficult to overcome the precision bottleneck when integrating systems.

Even though Chen Yansen pushes the Planck Clock talent to its limit every day, the road ahead is still fraught with difficulties.

Just as you finish solving problem A, problem B pops up in the blink of an eye, blocking your path again.

However, in the eyes of a group of top industry experts, Chen Yansen's abilities were already extraordinary. He had developed a more advanced control algorithm all by himself. It would have taken them seven or eight years to figure it out.

In less than half a month, the PhDs, professors and academicians from automation research institutes across the country changed their address for Chen Yansen from "General Manager Chen" and "Boss Chen" to "Mr. Chen".

Some people who were willing to put aside their pride even started calling him "Teacher Chen".

Among them is Zhang Yanjie from Harbin Institute of Technology, who will be almost fifty years old in four years, but he spends all his time hanging around Chen Yansen, calling him "Teacher Chen" repeatedly.

At this moment, Zhang Yanjie approached Chen Yansen with a laptop and asked, "Professor Chen, I spent half the night thinking about the disturbance compensation algorithm flowchart you mentioned yesterday, but there's still one part I don't fully understand."

He paused and then said, "When the extended Kalman filter estimates external disturbances, how do you balance response speed and estimation accuracy? I did a simulation with the parameters you provided. If the response is fast, the error will drift to more than 200 nanometers. If I try to reduce the error to less than 50 nanometers, the response speed will slow down. If I encounter a sudden disturbance, there is simply no time to compensate."

Chen Yansen stopped and stared at the screen for several seconds before saying, "Old Zhang, look at this disturbance curve. The external disturbance is not constant. For example, the pressure fluctuation of the air flotation component is sometimes high-frequency and small-amplitude, and sometimes low-frequency and large-amplitude."

You were using a fixed-gain Kalman filter, which naturally couldn't balance speed and accuracy. You could add an adaptive gain module so that the filter can determine the type of disturbance itself.

When there are small disturbances at high frequencies, increase the gain to speed up the response; when there are large disturbances at low frequencies, decrease the gain to reduce the error.

I did a simulation yesterday. Using this logic, the response time can be controlled within 10 milliseconds, and the error can be stabilized below 20 nanometers. Try these parameters today.

Zhang Yanjie frowned deeply, and after a long while, he slapped his thigh and exclaimed, "That's right! How come I didn't think of adjusting the gain according to the type of disturbance!"

Some technical obstacles are actually like a thin layer of paper; they can be easily broken through.

But without guidance, one might wander around the entrance for months or even years.

Hearing the commotion, several R&D engineers who were engrossed in their work gathered around.

Li Tuopu from the Department of Automation at Tsinghua University pointed to the module in the diagram and asked, "How should the threshold for this adaptive gain be set? If the type of disturbance is misjudged, will it affect the accuracy?"

The others also wore expressions of curiosity.

Chen Yansen nodded slightly, pulled up a chair and sat down, and directly used Zhang Yanjie's computer to pull up a set of experimental data: "We can use the perturbation data in the first 500 milliseconds for feature extraction. For example, those with a frequency of more than 100 Hz and an amplitude of less than 0.5 nanometers are classified as high-frequency small perturbations."
For frequencies below 50Hz and amplitudes greater than 1 nanometer, these are classified as low-frequency large disturbances. For those in the ambiguous intermediate range, a weighted algorithm is used to balance the gain. This method achieves an accuracy rate of over 98%, virtually eliminating errors.

Several professors from the Department of Automation at Tsinghua University had their eyes light up upon hearing this, and couldn't help but swallow hard.

The doctoral students from Harbin Institute of Technology looked at each other, a look of shock flashing in their eyes.

The more I interact with Chen Yansen, the more I realize the diversity of the world, the gap between people, and the insignificance of my own abilities.

Zhang Yanjie sighed inwardly. He knew that without Chen Yansen, even if they got together to study, they probably wouldn't make much progress in the research of motion control algorithms.

Just then, a researcher from the bearing group rushed in with a test report in hand, his face full of excitement: "President Chen, the test results for the air-bearing guide rail are in! The flatness error of this ceramic air-bearing bearing is controlled at 30 nanometers, which is 5 nanometers lower than the imported bearings we used before. Moreover, after 24 hours of continuous operation testing, the temperature rise was only 0.6 degrees Celsius, and the stability fully meets the standards."

Chen Yansen took the report, turned to the data page, and smiled slightly.

As expected!

The air flotation component is the core component for the movement of the mask stage, and in the past, it was neither available for purchase nor manufactured.

Today, times have completely changed!
Then, Chen Yansen looked at Zhang Yanjie and said, "You coordinate with the motion control group and do a new whole-machine test using the new air bearing."

"Okay, I'll go right away." Zhang Yanjie picked up his computer and test report, and left quickly with a cheerful smile.

If the doctoral students at Harbin Institute of Technology saw this, they would be absolutely stunned.

Because Zhang Yanjie was humble at this moment, completely unlike his usual serious demeanor at school.

As Xingyuan Technology acquires more and more patented technologies, the Anguo Association's investigation into Chen Yansen becomes increasingly detailed.

Li Qingsong, far away in Yanjing, casually flipped through Chen Yansen's investigation report, finally smiled slightly, and locked the document in the cabinet.

the other side.

A week passed in the blink of an eye. At 4 p.m. on Friday, Chen Yansen changed out of his lab coat, walked out of the R&D center, sat in the back of the Hongqi L5, and then signaled Lao Huang to drive to the airport.

　Godfathers, I'll update three chapters first, and try to write another one before midnight.

　　
　
(End of this chapter)