LDM

[@КонстантинЛетов-у6р]

What an interesting decision to lighten the structure in its complexity. Optical gyroscopes are more accurate and lighter than mechanical ones. Thank you for your work. We respect that. We are waiting for the electronics of cruise missiles!

[@mikkolankinen3330]

I wonder why not use MEMS gyro? It would be much more smaller and lighter.

[@Евгений-м2м2к]

@@mikkolankinen3330 I'm not very good at knowing gyroscopes, but maybe an optical gyroscope can handle high overload values?

[@tHaH4x0r]

@@mikkolankinen3330 Fiber optic (Or older ring laser technology, which is more expensive) gyroscopes generally have much higher bias stability. Bias stability is essentially how 'rock solid' the offset of the output rate is, given all other factors constant (temperature etc). This effect cannot be calibrated or measured out, so for longer term measurement periods (as in navigation for aeronautics) it is critical to have low bias instability. The 'cutting edge' trend for MEMS is trying to catch up with bias stability of fiber optic gyros, and it would be a breakthrough in performance for a certain size, but its certainly not at a point of maturity yet.

[@mased-v2j]

Great video! I always look forward to new uploads

[@ivekuukkeli2156]

Very much thanks for this video. The electronics is very precise but schematic is good analog design without any difficult to understand circuitry.

[@АлександрХрисанов-ж3о]

Очень красивые разъёмы выпускаются у нас с середины 80-х годов по французской лицензии.

[@beamer.electronics]

Your analysis and this subject are impressive, thank you.

[@fikamatyi2]

Great review. Thanks.

[@CuriousMarc]

Michel, maybe we could try to repair your fiber connection. We’d need to get access to a fiber cleaver and a fusion splicer, I may be able to borrow this from work. Great reverse engineering job as usual!

[@lelabodemichel5162]

Marc, unfortunately I have broken the fiber-optic connector of the photodiode when I tried to remove it. It is even harder now. I hope it can work with two channels only.

[@dennisdannunzio6112]

As long as we sweat and bleed to create beautiful analog opamps, transistors, etc. - and make them in china - we are only giving away all of those efforts to the ones that happily use it against us. Sending IP to hostile locations for mfg is suicide. You reverse engineering skills are fun to watch. I have seen many of these. Kudos to your skills - and your curiosity. A great combination.

[@NIOC630]

Hi! As usually a really nice reverse engineering! If you are interested, i have a working LID Splicer at home, if you have some time i could re splice the fiber for you if you think you can get it working then.

[@sergeyvakulenko4687]

Hi Michel, I have an almost working unit which was not disassembled (by "almost working" I mean that it responds to some serial commands, but gives an "error" status when data is requested). If you need any help with tracing the cables, I'll be happy to help

[@lelabodemichel5162]

Thanks but I have retraced all tracks and reconnected everything. Unfortunately I discovered another issue with the fiber optic, it is cut on the path of the sled.

[@sergeyvakulenko4687]

@@lelabodemichel5162 , anyhow, if you ever happen to splice the optical fiber back and need any info from another unit as a reference, I'll be there for you. I'm still hoping to get data from my unit some day, it would make a great DIYI desktop indicator of Earth rotation, with a mere $20k budget : )

[@ml1186]

Amazing!

[@buckstarchaser2376]

10:04 The voltage reference is there because the signal path has all the components to make an oscillator, but they don't want it to oscillate between heater and inefficient cooler in the small space. It would likely be slower to ready, and would not meet operating specs without the vref and low pass filtering.

[@wolpumba4099]

*Summary* ## LDM #372: Fiber Optic Gyro Summary (No Video Needed) *This video analyzes a Russian TIUS500 Fiber Optic Gyro (FOG) from a Tornado-S missile.* *Key Points:* * *(**0:05**)* *Damaged Unit:* The purchased FOG was incomplete, with cut wires, a missing power supply board, and a severed fiber optic cable, rendering it inoperable. * *(**6:35**)* *Reverse Engineering:* The video creator meticulously reverse-engineered the FOG's circuitry, including the photodiode amplifier, phase modulator circuits, temperature regulation, and light power regulation systems. * *(**4:28**)* *Tornado-S Confirmation:* The video confirms the FOG's use in Tornado-S missiles through photos and a physical demonstration of the gyro assembly. * *(**6:35**)* *Schematics & Analysis:* The video delves into the detailed schematic diagrams of the FOG's components, explaining their functions: * *(**6:35**)* *Photodiode Amplifier:* Amplifies the signal from the photodiode, which detects light passing through the fiber optic coil. * *(**7:07**)* *Phase Modulator:* Modulates the light phase to improve accuracy and sensitivity. * *(**7:39**)* *SLED Temperature Regulation:* Maintains a constant temperature for the Super Luminescent LED (SLED) using a Peltier element and thermistor, ensuring stable light output. * *(**10:16**)* *SLED Light Power Regulation:* Adjusts the SLED's light output based on the photodiode signal, compensating for aging and maintaining system sensitivity. * *(**11:48**)* *System DAC:* The system includes a Digital-to-Analog Converter (DAC) for various functions, including controlling the phase modulator and monitoring system parameters. *Overall:* The video provides a technical deep dive into the workings of a Russian FOG, offering valuable insight into its construction and functionality. However, the unit's damaged state prevents a live demonstration. I used Google Gemini 1.5 Pro to summarize the transcript. Cost (if I didn't use the free tier): $0.0448 Time: 22.12 seconds Input tokens: 10344 Output tokens: 817

[@piconano]

I read somewhere that the drift on laser gyros is 0.0001º/hour, where as the MEMS gyros drift can be as much as 10º/minute !! Is that true?

[@lelabodemichel5162]

MEMS G4300 : bias stability 7°/h FOG TIUS500 at constant temperature: bias stability < 1°/h. www.tronics.tdk.com/inertial-sensors/high-performance-mems-inertial-sensors/gypro-high-performance-mems-gyroscopes/

[@cogoid]

A MEMS gyro from a consumer drone is somewhat terrible, while any laser gyro is quite good in comparison. In this sense, there is a vast gulf in performance between the two. But strictly speaking, there are also vast differences between cheap consumer grade MEMS gyros and very expensive cutting edge MEMS gyros. And there is a range of performance in different models of laser gyros. The best MEMS are similar to the worst laser gyros. On top of this, one has to be very careful to state *precisely* how the performance is specified. There is some subtlety there. The numerical value of "º/hour" for the same unit can be a thousand times different based on what exactly is measured.

[@piconano]

@@lelabodemichel5162 the 4300 link says 0.4 °/h ! What? I bet they don't sell these to anyone.

[@piconano]

@@cogoid A navigational gyro is another beast and not sold to just anyone.

[@cogoid]

@@piconano Of course -- top of the line gyros are a work of art. No matter what physical principles they are based on, achieving top performance requires incredible attention to very subtle nuances. These specific units are quite good. They used to be available for sale internationally, and NASA has actually flown similar units from the same manufacturer in their missions.

[@-Halit-]

As a cs student I find your knowladge really interseting. Where can I learn like you?

[@erwe1054]

Для этого тебе нужно прожить его жизнь

[@denizzzka]

Is it possible to fetch software from it?

[@arinascimento547]

Hi Michel, the complete gyro isn't a IMU? It seems the three accelerometers are opposite to the FOG in the aluminum plate.

[@lelabodemichel5162]

Yes it is, on the opposite side there are 3 accelerometers.

[@SynthoidSounds]

Love these . . . always fun to see this mil tech get investigated

[@aabdev]

what MCU in on pcb?

[@lelabodemichel5162]

This is not a MCU but an FPGA

[@leandrocartes534]

hello le labo de michel good nise fibre optic gyro mi may from argentina

[@cogoid]

It is a real shame that the fiber optic cable has been cut! If this were a standard communication fiber, one could repair it relatively easily, using equipment that many fiber installers have. But this is a special polarization maintaining fiber, which is more difficult to splice. It might still be possible if somebody has the skills and the equipment.

[@tvsettv]

What if one wind of the cable is taken to reach the input? Will it distort/delay signal? There should be some adjustment means on the board I suppose.

[@cogoid]

​@@tvsettv Do you mean if it is OK to make the fiber shorter? It is no problem to shorten it. The scale factor will change, but this should not matter for a demonstration. If the fiber in other channels is intact, the unit might still work and produce correct output for the intact channels.

[@lelabodemichel5162]

I have also destroyed the associated photodiode when I tried to remove it to check the part number. Bad idea, the marking is not visible. I am not sure it will work with one faulty channel, but I will try. At least I will have to remove the associated resistor for the average light control. Repair is complicated, the fiber optic is inside a kind of silicone glue to avoid vibrations.

[@tvsettv]

@@cogoid yes, I mean that. I also believe that the board will have some adjustment means to make the two signals synchronized. When created, not all coils and cables are equal and for sure, it must be adjusted somehow.

[@cogoid]

@@lelabodemichel5162 There is a good chance that the channels work independently. The manual shows that there is a pair of pulse density coded outputs per axis. It looks like they should work on power-up without any additional initialization. So after you connect all the wires for the intact channels and for the power supply, it should be immediately obvious if any of the channels work. You must have already figured out that the stuff on the other side of the bulkhead is a three axis accelerometer unit. One board is the power supply. The three pizza-slice boards are custom analog to digital converters, which receive current output from the accelerometers. The accelerometers are of force-balance servo type, like the unit from the airplane which you have taken apart before, but more rugged. But maybe not rugged enough to survive the impact.

[@non-human3072]

In Australia nobody knows what FOG's are....it's hilariously sad.

[@jejak-penjajah_barat]

I have like this but from atacams

[@erwe1054]

Частные аналитики изучили электронику из частей разбившихся в Украине новейших российских крылатых ракет и вертолетов. Оказалось, что в высокотехнологичном оружии повторно используются технологии, которым уже несколько десятков лет. Кроме того, обнаружены западные компоненты, изготовленные после 2014 года. "Это оружие - лучшее в российском арсенале. Но оно содержит довольно низкотехнологичные компоненты", - говорится в материале. Отмечается, что доклад аналитиков подрывает нарратив кремля о том, что в рф - мощная и технологичная армия, которая может конкурировать своими разработками с армией западных противников. Оружие, которое росия использует для уничтожения украинских городов, зачастую создано на основе западных инноваций, несмотря на санкции, введенные против росии после оккупации Крыма. Мы увидели, что росия повторно использует одни и те же электронные компоненты в разных видах оружия, включая их новейшие крылатые ракеты и ударные вертолеты Самое интересное - уровень западных технологий, которые используют росияне. "Это уровень технологий конца 1990-х или середины 2000-х в лучшем случае", - отметил подрядчик NASA

[@Qsderto]

Dude, calm down. Microelectronic production is currently under construction in Russia. Until recently, the world believed in the international market. But USA destroyed everything .

[@artkutyuska9842]

Ну не знаю. Уровень электроники позволяет ФАБ-3000 гарантированно долететь до цели и испарить незадачливый отряд вооружённый супер пупер навороченоым оружием.

[@nostromons6325]

Умеют наши делать. Даже на вражьих каналах интересно посмотреть.

[@emmerad]

Using western parts because Russia can't make anything advanced themselves

[@xandervk2371]

Fairchild Semiconductor, Analog Devices, yeah, they know their stuff.

[@0x0NoFear0x0]

Are you in Ukraine or Poland maybe?

[@lelabodemichel5162]

No, in France!

[@0x0NoFear0x0]

@@lelabodemichel5162 where from are you getting those crucial parts? It is quite difficult to get access to such as toys even in Ukraine or Russia. Do you work for goverment maybe? Sorry I am just courious and a little bit jealous.

[@lelabodemichel5162]

I don’t work for the government. It is effectively difficult to get this kind of stuff, at least in France. If you live in Ukraine it is not so complicated.

[@Qsderto]

It is easier for me to develop anew myself, from the radio elements at hand, than to engage in reconstruction. A laser gyroscope is not that difficult, especially if you are friends with physics and mathematics.

[@paulpaulzadeh6172]

Expensive to target SHAHED drone with it 😂😂😂😂

[@cogoid]

This is from the Russian Tornado-S missile, which is used against ground targets. Its capabilities are somewhere between HIMARS and ATACMS, and it costs accordingly. From public records, first batch of 200 cost Russian DoD an equivalent of $100M, which is more than the cost of HIMARS, but much less than the cost of ATACMS.