Zhou Wei locked himself in his office for a full day and night. His desk was covered with draft paper filled with new symbols and logic diagrams. Instead of complex differential equations and transfer functions, the computer screen displayed a brand-new algorithm framework based on a "if...then..." rule base.
He abandoned the pursuit of that elusive "perfect mathematical model" and instead began to build a fuzzy control system that simulated the "feel" of a master craftsman.
He defined several simple "fuzzy" concepts:
• Vibration magnitude: divided into three levels: "small", "medium" and "large".
• Controlling actions: divided into "no movement", "fine adjustment", "medium adjustment" and "emphasis".
• Trend of change: divided into "increasing", "decreasing", and "remaining basically unchanged".
Then, he began to write the rules, like summarizing the experience of a master craftsman:
Rule 1: If the vibration is "small", then the control action "does not move".
• Rule 2: If the vibration is “medium” and the trend is “increasing”, then the control action is “fine-tuned”.
• Rule 3: If the vibration is “large” and the trend is “increasing”, then adjust the control action to “medium”.
• Rule 4: If the vibration is “large” and the trend is “decreasing”, then the control action should be “fine-tuned”.
Rule 5: If the vibration "increases" after control, then the next control action will "reverse".
...
These rules may seem simple or even crude, but they no longer rely on precise system parameters. Instead, they react based on the macroscopic state and changing trends of vibrations. They do not strive for a perfect solution all at once, but rather, like an experienced craftsman, carefully and step by step, probe towards that stable state.
When Zhou Wei, sporting dark circles under his eyes, walked out of the office with this brand-new draft of a control algorithm based on fuzzy logic, Liu Li and Sun Mei both surrounded him.
"How is it?" Liu Li asked anxiously.
Zhou Wei handed them the draft, his voice hoarse but with a hint of excitement: "We've changed our approach. Instead of arguing it head-on, we'll 'negotiate' with it."
Liu Li's eyes lit up as she looked at the simple rules: "Yes! That's the feeling! Just like Master Wang adjusting the machine, it's not a one-off deal!"
Sun Mei looked at it carefully and nodded, saying, "The rules are clear, the amount of calculation should be much less than before, the hardware requirements are lower, and the response speed may be improved."
The three immediately began implementing and simulating the new algorithm. Zhou Wei programmed the rule base, Sun Mei was responsible for "fuzzifying" the analog signals from the sensors, converting them into fuzzy quantities such as "small, medium, and large," and Liu Li assisted in determining the specific output force corresponding to different control actions.
In computer simulations, they tested the new algorithm using simulated spindle vibration data. The results were encouraging!
Compared to the old algorithm, which was either slow to react or prone to severe instability, the new algorithm demonstrates remarkable robustness (anti-interference capability). Faced with noisy and delayed input signals, it no longer panics but instead, like a composed veteran, calmly and methodically outputs control commands according to pre-defined rules. Although the speed of vibration suppression is not the fastest, the process is very smooth, and there are no more positive feedback loops that could cause system collapse.
"Success! The simulation passed!" Zhou Wei looked at the steadily decreasing vibration curve on the screen and almost jumped up with excitement.
“This approach is really feasible!” Sun Mei couldn’t hide her joy.
Liu Li breathed a long sigh of relief, a long-lost, relaxed smile appearing on her face: "It seems that sometimes 'home remedies' can solve big problems."
The shift in thinking was like finally seeing light at the other end of a dark tunnel. Although there's still a long way to go, and repeated debugging with real prototypes is needed, the biggest cognitive obstacle has been overcome. This new path, based on experience and rules, has pointed them in the right direction to move forward.
Continue read on readnovelmtl.com