Eagle Sauce: The 055 destroyer was launched into the sea just after the founding of the country?

Inside the command center of the Northwest Military Test Base, Fang Yu breathed a sigh of relief as he looked at the data feedback after the PL-10 missile on the test bench successfully hit the target.

The team members' faces were filled with joy of victory and they high-fived each other to celebrate.

But Fang Yu knew that the most critical technical challenge of the J-20 had not yet been resolved - the flight control system.

A week later, Fang Yu stood in front of a whiteboard, facing top electronic engineers, aviation control experts, and mechanical engineers transferred from all over the country.

He ran his fingers over the complex system block diagram drawn with chalk on the whiteboard, his brow furrowed.

"The traditional mechanical hydraulic control system cannot meet the needs of the fourth-generation aircraft,"

Fang Yu got straight to the point.

"What the fourth-generation aircraft needs is a fully digital fly-by-wire flight control system, also known as a 'fly-by-wire flight control' system."

“Fly-by-wire?”

An elderly aviation control expert asked doubtfully.

"Mr. Fang, forgive my ignorance, but what is this concept?"

Fang Yu drew a completely new control architecture on the whiteboard.

"Traditional aircraft control systems use mechanical linkages to directly control the control surfaces, but fourth-generation aircraft require computers to receive pilot instructions and perform complex calculations before controlling the control surfaces."

“This allows for a super-stable design, enabling more flexible configurations that would otherwise be unstable.”

Professor Zhang from the Institute of Electronic Engineering shook his head.

"That's almost impossible to achieve."

"Even our most advanced computers are about the size of a large wardrobe. How could they possibly fit into an airplane cockpit?"

“Not to mention processing complex flight data in real time.”

Fang Yu took out a thick notebook and turned to a page filled with densely packed circuit designs.

"I've already thought about this."

"I designed a set of small transistor-based computing units, each responsible for a specific function."

“While not as powerful as a real computer, it’s enough to handle basic flight control logic.”

The room was silent, and the experts looked at each other.

This technical idea was so advanced that it was difficult for them to digest it for a while.

If we only use transistor logic circuits without a real central processing unit, can we ensure flight safety?

Once the system fails, the consequences will be disastrous.

Fang Yu also had concerns in his heart, but he knew that he had to break through this level.

In the first month, the team designed the preliminary circuit architecture.

However, when they tried to build a prototype, they immediately encountered a serious challenge.

"Mr. Fang, this amplifier circuit has poor stability when the temperature changes,"

Electronic engineer Li Ming pointed at the constantly fluctuating signal curve on the oscilloscope.

"Once the aircraft takes off from the ground and reaches high altitude, the temperature drops sharply and the entire system may go out of control."

Fang Yu scratched his hair and fell into deep thought in front of the laboratory table.

Future flight control systems use temperature compensation and self-calibration techniques, but that requires more advanced integrated circuits.

How can we use existing technology to solve the problems we face?

After pondering for a moment, Fang Yu suddenly had an idea.

"Got it! We can use redundant design!"

“Three completely independent control channels, majority voting principle.”

Li Ming's eyes lit up.

"Three independent systems working simultaneously, taking the majority result as the final output?"

“This really does improve reliability!”

"Mr. Fang, how did you come up with such a brilliant design?"

"This, this is simply..."

Hearing this, Fang Yu smiled modestly, waved his hand, and said nothing.

After all, he couldn't say that he had a system with future technology in his head, right?

……

After solving the circuit stability problem, the team immediately faced the second challenge - the servo feedback system.

Traditional mechanical feedback is no longer suitable for high-speed, highly maneuverable fourth-generation aircraft.

"To adapt to the fourth-generation aircraft, we need a new servo motor and position sensor,"

Proposed by mechanical expert Mr. Wang.

“But existing motors are too slow to respond and cannot handle the instantaneous control demands of supersonic flight.”

Fang Yu thought of the future linear motor technology, but it was not possible under current conditions.

He opened his notebook again and drew a design for an improved permanent magnet synchronous motor.

"With this in mind, we can reduce the rotor inertia and increase the magnetic field strength."

"Combined with a special drive circuit, the response speed can theoretically be tripled."

Over the next two weeks, the team worked day and night to debug the new motor.

The lab was filled with the hum of motors and the ticking of electronic equipment.

Everyone's face was tired, but their eyes were shining with the desire for a breakthrough.

After the new servo successfully completed the high-speed response test, Fang Yu led the team to turn to the third challenge - the sensor system.

Fourth-generation aircraft need to monitor hundreds of flight parameters in real time, but the sensor technology of the 50s is far from accurate and fast enough.

“We need to monitor at least three-axis acceleration, three-axis angular rate, air pressure, temperature, angle of attack, and sideslip angle,”

Avionics expert Mr. Liu made a list.

“It is difficult for existing technologies to meet both precision and volume requirements.”

Fang Yu took out a small metal device.

"This is a prototype of a micro-electromechanical gyroscope I designed. It is ten times smaller than a traditional gyroscope and has a 30% improvement in accuracy."

“How…how did you do that?”

Engineer Liu took the device in surprise and examined it carefully.

"Using the piezoelectric effect and resonance principle,"

Fang Yu explained.

"The deformation caused by vibration can be converted into an electrical signal, and after precise calibration, accurate angular velocity data can be obtained."

The last and most difficult challenge is system integration and algorithm development.

The flight control system needs to process complex nonlinear control algorithms, which is almost impossible to achieve without powerful computing power.

Fang Yu stayed up three nights in the office and finally came up with a solution.

"We can use table lookup and piecewise linear approximation to pre-calculate the control outputs for various flight conditions and store them in the core memory."

“Only table lookup and simple interpolation calculations are required during flight, which greatly reduces the computational burden…”

……

After six months of hard work, the prototype of the world's first fourth-generation aircraft flight control system was finally put into operation on the test bench.

When simulation tests showed that it could stably control a highly unstable airframe configuration, the entire team burst into applause.

Fang Yu looked at the test data, a gleam of victory in his eyes.

This ahead-of-its-time flight control system will make the J-20 a true fourth-generation aircraft, giving China the upper hand in this arms race.

His fingers gently stroked the control panel, and he was already planning his next challenge - the development of stealth coating...