95 kg drone with howyadoin' Arduino bodgery crashes - made in Straya! - Page 1
Forum section: electronics / general

author: grahamparks
author_rank: Newbie
timestamp: February 22, 2021, 09:20:20 am
content: This incident happenned in 2019 but the Air Accident Investigation Branch has only just published its report.QuoteThe amazing thing is how bodgy the electronics were:QuoteQuoteQuoteThe kill switch relied on Normally Closed relay contacts, and there was no mechanism to find out if the kill switch radio channel was working until they pressed the button and nothing happened. The bare board hanging out of the laptop in the photo below is the safety-critical transmitter.The main control software was designed to continue executing the last command it received if it lost contact, in this case continuing to climb into controlled airspace. There was no GPS or automatic return to base functionality. There was no data logging.They were planning to make the thing carry a human in the next iteration.Full report here, with more pics:https://assets.publishing.service.gov.uk/media/602bb22f8fa8f50388f9f000/Alauda_Airspeeder_Mk_II_UAS_reg_na_03-21.pdf

author: Raj
author_rank: Frequent Contributor
timestamp: February 22, 2021, 09:33:24 am
content: This is why we can't have nice things...hopefully no one lets the lawmakers take a look at this.

author: Ice-Tea
author_rank: Super Contributor
timestamp: February 22, 2021, 09:40:56 am
content: Classic "I know electronics because my Arduino makes a LED blink".I'm sure we'll see a *lot* more stuff like this in the future.A POC does not a product make...

author: Rerouter
author_rank: Super Contributor
timestamp: February 22, 2021, 09:42:59 am
content: I would actually flip it to what the minimum bar is moved to for this level of project, and I don't disagree with any of there points, invert all of what they said was wrong, and you get the passing bar for what they would like to see,I personally would not want to ever fly a human on something I have built, but the question changes to, if all the concern points where addressed, e.g. proper tested kill switch, properly assembled electronics, firmly mounted in a weatherproof enclosure, would that meet the bar? again not for the human part, just for the can this be flown aspect,I would eventually like to hook a panorama camera rig up to a drone with a long enough battery life, but my confidence that it will stay in the sky under all conditions has put me off attempting it.

author: Kean
author_rank: Unknown
timestamp: February 22, 2021, 09:44:30 am
content: Quote from: Ice-Tea on February 22, 2021, 09:40:56 amManagement rarely understands the difference between a POC, a prototype, and a pilot production unit.

author: Kean
author_rank: Unknown
timestamp: February 22, 2021, 09:48:32 am
content: Quote from: grahamparks on February 22, 2021, 09:20:20 amI am appalled by the low build quality for something that needed to be airworthy, but I find these omissions even more incredible.

author: beanflying
author_rank: Super Contributor
timestamp: February 22, 2021, 10:03:33 am
content: Quote from: grahamparks on February 22, 2021, 09:20:20 amMade in Australia and NEVER APPROVED FOR FLIGHT by CASA in Australia!As I have had a bit to do with CASA over several decades and know one of their inspectors it never would get approval in that state! So take your title and shove it where the Sun doesn't shine this is NOTHING to be made light of!This is a case of a marketing company with little to zero clue of flight systems that LIED to the UK Authorities who then didn't in turn do THEIR job on the airframes and inspect them.

author: Ian.M
author_rank: Super Contributor
timestamp: February 22, 2021, 10:40:21 am
content: Yeah, I saw that on 'The Register' a few days ago and considered linking it here.Either the builder's never even heard of the NASA TECHNICAL STANDARD for SOLDERED ELECTRICAL CONNECTIONS,NASA-STD-8739.3, let alone read it, or was deliberately and wilfully ignorant and negligent.I'm not saying all of 8739.3 will be applicable to an experimental drone or light aircraft, but any deviations from it should be explicitly decided on and documented.Also, if you are flying a high value prototype drone, or operating in an area with anything except a very low population density, why wouldn't you have a parachute fitted, that will deploy if the kill switch is operated during flight, or if the control link is lost for an extended period or at critical low battery? It will probably reduce impact damage enough to save your aircraft, and will vastly reduce the risk of serious injury to bystanders.

author: tszaboo
author_rank: Super Contributor
timestamp: February 22, 2021, 11:07:31 am
content: Quote from: Ian.M on February 22, 2021, 10:40:21 amWhy would it be applicable to anything but electronics made for NASA?The industry standard is IPC-610 Acceptability of Electronic Assemblies.Others:This is a proof of concept. It is unfortunate that the accident happened, but you shouldn't expect production quality boards and wiring for such. Obviously this was for a demonstration, the airframe seems to be in it's final shape, the electronics obviously not.There is a seat on it, but it is unmanned.But there is nothing new here. It is generic practice, that unfinished aircraft fly. Usually it's the job of test pilots, and it is a damn dangerous job.If you regulate it, the only achievement is that you kill the hobby of drone building.

author: beanflying
author_rank: Super Contributor
timestamp: February 22, 2021, 11:18:03 am
content: Quote from: NANDBlog on February 22, 2021, 11:07:31 amIn Oz there is NO way to fly this airframe 'legally'. There is a complete approvals process even for test flights. Those of us that play in this space take it very seriouslyNational Government body (including the RULES to be followed PRIOR to flight)https://www.casa.gov.au/dronesPeak Industry Body for Commercial UAV'shttps://aaus.org.au/A bit of HISTORY of Oz UAV'shttps://barnardmicrosystems.com/UAV/milestones/atlantic_crossing_1.htmlI have flown with three of the guys pictured and named here, another good mate of mine of 35 years was their Chief Pilot at the time and another mate of mine built the Airframes before and after this flight for some time.

author: Saskia
author_rank: Super Contributor
timestamp: February 22, 2021, 01:22:58 pm
content: Well, in that case it seems quite obvious that the company has willfully broken the law in quite a few countries and instances. Where is the prosecutor and why has the company not been shut down ?And why do I see parallels to the issue with the swiss guy who want to test his non certified eeg concoction on unsuspecting victims ? ...

author: Bicurico
author_rank: Super Contributor
timestamp: February 22, 2021, 01:43:06 pm
content: I know my opinion may/will be criticised, but I did read through a big chunk of the report and I don't think this project was nearly as bad as some comments on this forum may suggest.The pilot did comply with all/most norms, as far as I can tell. When I saw the post starting this thread, i immediatly imagined a home-made UAV operated by an amateur pilot without any authorisation, which was definitely not the case.The UAV has design flaws and a built-quality that is not on par with standards and recommendations. I understand that, but: if the bar is raised too high and too many norms have to be studied and implemented, it will basically eliminate any entrepreurship in this area.Imagine I have some great ideas for an UAV. No matter how much I know of mechanics, aerodynamics, electronics and even if I would setup a small team, we would never be able to handle all the regulations the report is suggesting. But that would not void the fact that we may have a great application. And in my opinion, any prototype should be much less regulated than a commercial product.If in a case like this, the authorities autorized a demonstration flight of a prototype and all generic flight regulations have been met, a clear airspace has been provided, then why shouldn't they be able to fly the prototype?If this prototype is at a point that an investor is found and the prototype is to be transformed into a commercial product, then yes, by all means every regulatory aspect needs to be implemented and checked.But please don't be too severe on prototypes, otherwise independent R&D will be made impossible.Regards,Vitor

author: beanflying
author_rank: Super Contributor
timestamp: February 22, 2021, 01:52:22 pm
content: CompleteYou CANNOT allow EVER completely unregulated uninspected air vehicles of this weight to fly period! There is no first world country I am aware of that would allow this and the only reason this go through is the Company LIED.The CASA (Australian) regs for heavy UAV or Model inspection to 25kg are really really simple. When you get up in weight they are not and when you want to strap a human into it go to another whole level. I have helped with the paperwork for one of these and it was an afternoons work and a few hours at CASA.If this bunch of tossers wanted an easier path to proof of concept then they should have opted for smaller rather than a dangerous PR stunt!

author: filssavi
author_rank: Frequent Contributor
timestamp: February 22, 2021, 02:13:47 pm
content: Quote from: Raj on February 22, 2021, 09:33:24 amI instead hope they take a long hard look at this...If they flew the thing in an open field (with the owner permission) by themselves I would bet my left kidney that nobody would have cared and no investigation would have been even started.But no they flew the damn thing at an airshow with a 35.000 peoples in attendence, what do we need to wait, for one of these things to crash in the middle of a crowd injuring or even killing few people?Quote from: Bicurico on February 22, 2021, 01:43:06 pmYou don't need to fly your shoddily built independent prototype at an air-show...do it in the open with the bare minimum amount of people necessary until you have enough money to do the job properlyUnfortunately this is the other side of the coin of the Arduino movement, it introduced a lot of people to the electronics hobby, however it also gave rise of a generation of hubris filled "engineers" that really don't know any better.Nothing is more indicative of this than the Normally closed security relay, there is no ammount of screaming abount management pressure to convince me that it was anything but designer incompetence, it is not a matter of cost (relay usually have both type of contacts, and regardless there is no price difference), it is not a matter of circuit complexity (there is not really too much difference); it is just sheer incompetence, arrogance, and willingness to throw stuff together

author: Syntax Error
author_rank: Frequent Contributor
timestamp: February 22, 2021, 03:26:31 pm
content: Quote from: Ice-Tea on February 22, 2021, 09:40:56 amFlight qualified Arduino Nano compatibles from ebay. NOT.95 kilos is like having a truck battery falling out of the sky from 8000 feet. That's about 150mph on impact?

author: tszaboo
author_rank: Super Contributor
timestamp: February 22, 2021, 03:46:43 pm
content: Quote from: Saskia on February 22, 2021, 01:22:58 pmWhy? This happened in the UK, you cannot apply AUS law to UK.Quote from: beanflying on February 22, 2021, 11:18:03 amMaybe. Maybe the law is different in the UK. This is from the report:QuoteSo they had contacted the authorities, and they had rights for the test flight. They even went to a local airfield to carry out the test and they didn't just take off in the middle of a town center.

author: grahamparks
author_rank: Newbie
timestamp: February 22, 2021, 04:20:54 pm
content: The report makes clear that itshouldn'thave been licensed to fly in the UK but the application was taken largely at face value and no physical inspection of the hardware took place. That has (hopefully) changed.It would be nice to assume other country's authorities wouldn't be quite so naive in the same circumstances, but who knows...

author: SilverSolder
author_rank: Super Contributor
timestamp: February 22, 2021, 04:38:31 pm
content: Quote from: grahamparks on February 22, 2021, 04:20:54 pmThe one thing authorities are really good at is locking the stable door after a horse has bolted. I don't think it will be as easy to get permission to fly something like this in the future...

author: filssavi
author_rank: Frequent Contributor
timestamp: February 22, 2021, 04:40:08 pm
content: Quote from: grahamparks on February 22, 2021, 04:20:54 pmUsually most of the time it is not being naive, just severe lack of funding

author: Bud
author_rank: Super Contributor
timestamp: February 22, 2021, 04:52:16 pm
content: Let them do the flight with the pilot in the cabin, just let them do it, then it will be what, 170 kilos falling down from the sky and a bit of a scene where it hits the ground.

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 22, 2021, 05:02:39 pm
content: Quote from: SilverSolder on February 22, 2021, 04:38:31 pmSo far regulations are different depending on the country... Regulation at the EU level was pretty "light" until recently. Starting Jan 2021, it's more stringent and several classes are defined depending mainly on weight. The highest class as far as I've understood is called C4 and allows drones up to 25kg. Beyond 25kg, it's not a drone.I dunno what the rules were in the UK at the time, but even without any physical inspection - just judging from the weight, which admittedly would have taken exactly 2 seconds, it should never have been allowed to fly. 95kg? It's absolutely nuts.

author: Saskia
author_rank: Super Contributor
timestamp: February 22, 2021, 07:14:49 pm
content: Quote from: NANDBlog on February 22, 2021, 03:46:43 pmDid the report not state that they lied to the Oz authorities and misrepresented the state of the Oz permit to receive the uk clearance ?Could be that I got this wrong, but if not, those would be criminal offences.Entering controlled airspace without authorization is a criminal offence in most countries. Having a working flight termination system may be a prerequisite to get a launch permit.Not having a chute based recovery system in place that automatically fires under predefined conditions is a huge no-go.

author: tszaboo
author_rank: Super Contributor
timestamp: February 22, 2021, 10:49:34 pm
content: Quote from: Saskia on February 22, 2021, 07:14:49 pmIANAL, but I also wouldn't state that they broke the law without proof of it.I also dont want to read through all 65 pages of the report, no matter how interesting it is.But his caught my eye:QuoteUnfortunate. They set the legal limits for their transmitter, and lost control because of the reduced range.

author: grahamparks
author_rank: Newbie
timestamp: February 22, 2021, 11:18:17 pm
content: Quote from: Saskia on February 22, 2021, 07:14:49 pmThey told the British that is wasrequired to be certifiedin Australia, not that it had actually been certified! An amazing bit of blagging if it's as bald as the report implies.The British CAA seems to have granted their license on the assumption the drone would be operating at a very low altitude, at low speeds and in a designated area away from buildings and people, and the kill switch would ensure that. Hence it didn't need parachutes or anything fancy like actual safety.It makes the shoddiness of the kill switch system much much worse.

author: Saskia
author_rank: Super Contributor
timestamp: February 23, 2021, 12:05:32 am
content: Well, tbh, I think those are 2 different issues. When I have a kill switch or flight termination system, I must consider the weight of my vehicle and possible impact and endangerment my vehicle poses to the unsuspecting public. Eg.. If I remember correctly, the Delft university group had to build a system that separated other airframe if radar lock was lost, thus effectively destroying their vehicle. In our own concoctionswee had to build in apogee detectors that automatically deployed chutes (drogue and main) at predefined altitudes, and depending on the weight of our vehicle had to put in at least one independent backup system. Still, our launches were held way outside populated areas ...Anyway.If the drone operators misrepresented facts in their application the state prosecutor should have a look at the data and decide whether to initiate criminal proceedings.Just my 2c

author: Syntax Error
author_rank: Frequent Contributor
timestamp: February 23, 2021, 05:09:05 pm
content: @eevblog, Dave, could you get a video or something out of the concept of failsafe systems?Staggering their power cut relay was always closed. Relying on the loss of a LoRa (how far does that transmit?) signal to then energise the relay, seems like a design dreamed up by someone with an Arduino breadboard starter kit. Hang on a moment, their kill switch subsystem IS built on a breadboard-to-solder board?!This said, I am sure there are plenty of EEs here who have experienced many 'failsafe on' designs.From the AAIB report:

author: bd139
author_rank: Super Contributor
timestamp: February 23, 2021, 05:40:50 pm
content: This was interesting.Just them looking at their own shit show and still being of the mindset"yeah we'll fly it anyway"shows the perpetrators should have an example made out of them. This is the same mindset of criminals; they chose to put people in danger intentionally through selfishness and apathy and lied about it. There are no excuses.Now I'm going into kill mode because I'm quite frankly fucking fed up of some of the stuff I am seeing these days coming from the "maker community". All I see is deathtraps, fire hazards, shit falling out of the sky and people blindly copying this as the status quo. What is even worse is the ceremonious back patting that comes with it, the trite cuteness and general drenching of marketing ooze. It's quite frankly embarrassing as a human looking at some of this shit and people thinking it's ok to kick out there. It really fucking pisses me off.I've had my own run in with this shit...I'm in the software industry and we tend to have similar non-engineering background folk coming up with all sorts of random shit all the time. In this case it was some "build traffic lights". So when the main software build fails it goes red, when it's ok it goes green so you can be shamed into fixing it. Well off goes the self-appointed maker and buys a 240V traffic lights head from ebay. This is immediately equipped with an arduino and a relay board, the only tools being employed being a swiss army knife, a couple of screwdrivers and some double sided tape. It appeared when I was away for a week I suspect because he knew I was going to rip it a new arsehole. Well I did. The entire thing was metal chassis, not even earthed - he'd cut the earth wire off. The mains lead was tied in a knot behind the sharp edges of the chassis which had already started cutting through it. All the boards were double sided taped inside and the thing was wired up with 7/0.2 wire which the insulation had already partially melted away. This was left plugged into a random desktop PC in the corner and hung off a coat hook on the coat rail where it was bashed around a people went in and out of the office. When I arrived back I took it and threw it in the skip. When I shook it, the relay board came unstuck. It probably would have with the heat anyway and killed whoever touched it next.The frustrating bit? I got complained at for the attitude. I just saved you from burning your office to the ground or electrocuting your staff. Fuckwits.And that's the problem: fuckwits. Wall to wall fuckwits. Need to lock their hands away somewhere separate from the rest of them.Edit: apologies for the tone - I had a crappy day fixing half arsed engineering...

author: AVGresponding
author_rank: Super Contributor
timestamp: February 23, 2021, 07:04:35 pm
content: Quote from: Syntax Error on February 23, 2021, 05:09:05 pmYes, and it's really quite staggering how people that apparently manage to tie their own shoelaces of a morning can't understand what the word "failsafe" means.

author: bd139
author_rank: Super Contributor
timestamp: February 23, 2021, 07:34:25 pm
content: Problem is it’s not how people conceptualise things. The general way people think is assuming success and looking out for danger. But that doesn’t work for unexpected scenarios. So you have to assume failure and know what criteria and measurements you can make to maintain success.

author: AVGresponding
author_rank: Super Contributor
timestamp: February 23, 2021, 08:26:47 pm
content: I prefer to expect failure, and think how that can be made to happen safely, then think of ways to prevent the failure.I guess that makes me a pessimist!

author: Syntax Error
author_rank: Frequent Contributor
timestamp: February 23, 2021, 09:35:41 pm
content: Quote from: bd139 on February 23, 2021, 05:40:50 pmDo you work in Shordich or Kings Cross London? Google has turned the whole tech workplace into a dissolute campus playground for cash-rich skill-short startups. Oh joy, another nerd with a nerf gun.Quote from: AVGresponding on February 23, 2021, 08:26:47 pmOnly if you're holding that half empty glass upside down.I looked up those modules used in their 'avionics bay' (the grey plastic box used for garden fountains). The usual hobbist fare: A £4 Arduino Nano compatible (ATmega328P 16MHz), a £24 LoRa 433Mhz telemetry module, a £3 single channel 5V relay module and, a £3 GY-521 MPU-6050 3-axis 16-bit gyroscope-accelerometer module. In all, £100 worth of modules and parts controlling the whole UAV's guidance system.The GY-521 MPU-6050 accelerometer module, of which there were two pictured, is an I2C (only) bus device. Thinks, an I2C bus monitoring the pitch-yaw-roll of a 95 kilo flying lawn mower. What could possibly go wrong?The GY-521 datasheet suggests applications for this sensor include, "location based services anddeadreckoning". I reckon dead too.http://www.haoyuelectronics.com/Attachment/GY-521/mpu6050.pdfAnyone seen my drone?

author: bd139
author_rank: Super Contributor
timestamp: February 23, 2021, 09:48:37 pm
content: So basically the avionics package was about 40 quid?Quote from: Syntax Error on February 23, 2021, 09:35:41 pmI did bounce around the startup scene there for many years but it was limited to ripping them off as a contractor. My house is built on the crushed dreams of millennial hipsters.

author: tszaboo
author_rank: Super Contributor
timestamp: February 23, 2021, 10:22:48 pm
content: Quote from: bd139 on February 23, 2021, 07:34:25 pmYou know, there is something I like about the job I'm doing now. I have to follow a standard. This standard is saying:Lets assume that every single component in your system can fail, there are multiple ways for this.Prove, that it is safe, even after the failure.

author: Cerebus
author_rank: Super Contributor
timestamp: February 23, 2021, 10:28:01 pm
content: Quote from: Bicurico on February 22, 2021, 01:43:06 pmYou obviously didn't read enough of the report to be aware of these things:The approval specified, as a condition, where the operator was to be on the day, they were positioned somewhere else.The approval specified, as a condition, where the observers were to be on the day, they were positioned somewhere else.The approval specified, as a condition, the operating area, the UAV was flown outside of it.The approval specified, as a condition, the take off point, the take off was from somewhere completely different.The approval was them using a transmitter operating at 25mW, a 10mW transmitter was used.Basically the operators departed wholesale from the operating procedures agreed for the day. There's more, but that alone is an indication that the operators were woefully negligent in complying with their obligations.In light of that the CAA has let them off very lightly, I suspect in embarrassment at their own failures in not having adequate procedures or staff who had a clue how to go about managing the whole process - it seems the department involved has been put together in the most ramshackle fashion possible (see the CAA report for details).I recommend reading the whole report. It's quicker and easier to read than its page count might at first suggest.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 23, 2021, 10:28:56 pm
content: Quote from: bd139 on February 23, 2021, 05:40:50 pmI can totally relate - I've lost count of the times I've come in to a "design studio" of some sort who realised too late that "Arduino does not scale" and need me to tear it up and build something from scratch in a week.Typical example being someone who thinks a "bench power supply" is a Mean Well (or cheaper) box with maybe half the strands of a mains cable connected to the exposed screw terminals, which has become buried under a few sheets of paper on an office desk just waiting to bite the person sitting opposite, onto whose desk it had encroached.Or someone whose sole means of disconnecting a large sprawling mains powered setup is to pull out the plug from the extension lead lying on the floor...Or someone who, during an expensive session in a film studio can't figure out why his 12V lighting setup doesn't work when it's run through 25 metres of thin speaker cable...I could go on...I'm truly amazed I've not heard of serious injuries or fire incidents - maybe they were embarrassed to mention.

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2021, 10:43:13 pm
content: Quote from: mikeselectricstuff on February 23, 2021, 10:28:56 pm"Arduino would not pass even the most basic EMC test" is also a big issue here. 95 kilos of electrically noisy motor systems driven by an Arduino is a death trap.

author: Cerebus
author_rank: Super Contributor
timestamp: February 23, 2021, 11:29:29 pm
content: Quote from: bd139 on February 23, 2021, 05:40:50 pmThe problem with that solution is that to lock their hands up somewhere separate from them you first need the hands to be separated. Leave them alone for an hour in a workshop with some stock, a Bandsaw, a Lathe, a Milling machine and a copy of "A Makers Guide to Metalwork" ought to get the job done efficiently and with the minimum of human involvement.I'msowith BD139 on the walking personifications of the Dunning–Kruger effect that perpetrate this crap. The most dangerous thing about these people, and the cult of personality that goes with it, is that when challenged by people who actually know what they are talking about they don't react the way any intelligent person would and reevaluate their level of understanding, they just go into denial.For anyone who hasn't yet realised what a shitshow this was, here's one resistor from what was, let us remember, a safety critical system.There is no way that is acceptable in a safety critical system, with no redundancy, that flies 95 kg around in the air and that was capable of getting high enough to return to earth at terminal velocity with a kinetic energy of atleast100 kJ.There are more pictures in the report of egregiously bad construction. All the electronics in the UAV were held in place with bloody nylon cable ties just looped about the frame members - not a screw, shakeproof washer or safety wire anywhere in sight.The CAA don't come out of this covered in glory either. From the report:QuoteTranslation: The section leader had organised drones for the police or fire brigade and probably had no prior regulatory experience, or aerospace experience. Most, possibly all, of their staff all came from university straight into the CAA to work as data entry clerks and they decided it would be a good idea to put them to work as "Technical Inspectors" or "Surveyors". You can guess what's happened by what is omitted, all mentions of prior qualifications or experience. For all we know they were English or Philosophy graduates and the fact that they don't call out degrees in relevant areas is a strong indicatior to me that I'm on the right path.Edit: Re-reading this I'm reminded of a phrase that commonly crops up in UK criminal that goes something like this: "A personal will be guilty of an offenceif they knew or should have knownthat<something they omitted to do was criminally negligent>". You'll find that as far back as Victorian laws. There's a duty on people to recognise when they are out of their depth so that if they didn't know enough to know whether something was right or wrong they should find someone who does know what is right and what is wrong. That bloody resistor screams at me that somebody "should have known" that it's wrong or should have had the sense to "ask a grown up".

author: Cerebus
author_rank: Super Contributor
timestamp: February 23, 2021, 11:59:59 pm
content: Quote from: coppice on February 23, 2021, 10:43:13 pmThe Arduinos were driving ESCs which were in turn driving the motors. That is no comfort though. A lot of those ESCs are designed and built by drone hobbyists who've 'gone pro'. They graduate to circuit design, but globbing together bits of sub-circuit and fiddling with values until it all sort-of works. We had a relatively recent discussion where it became clear that the denizens of that community have little clue how it all really works. I watched a few videos and the lack of basic technical grasp of how motors and motor control systems work is astounding. One of the 'truths' circulating in the hobby drone community is that if you run a BLDC motor with no load (i.e. propellor) it runs away faster and faster until it explodes. No amount of demonstrating to one such hobbyist that this was not true because BLDC motors are only capable of running as fast as the driving current waveform would be accepted. They insisted on clinging to their beliefs even though there was patiently explained hard evidence in front of them. The probable explanation for the belief is that the ESCs are badly designed and thecontrollerscan exhibit this runaway behaviour, but the cargo cult explanation is that "BLDC motors cannot be safely run unloaded.".Faced with that level of lack of basic technical knowledge or information, and unwillingness to learn, preferring to follow some sort of 'Maker' cargo cult, how the hell are you going to get them to understand and mitigate EMC issues? You'll get back something like "Well I've been doing this for X years, and it works. So what I know must be right, and if this 'EMC' thing you're talking about is a problem I would have encountered it, and I haven't, so it isn't.".The next week an EMC problem you warned them about sends their drone at full speed into the queue of little kids waiting for an ice cream at the county fair where they are doing a demonstration flight, and the local CB'ers are stoking up their linears on a stall the other side of the field.

author: SilverSolder
author_rank: Super Contributor
timestamp: February 24, 2021, 12:24:36 am
content: If these people had been car hobbyists instead of into drones/electronics, there would have been higher requirements that they would have to pass in most countries / states!Certainly around here, if you made your own car, it would have to be inspected in order to be licensed to be on public roads. And the inspectors know what they are doing...

author: vk6zgo
author_rank: Super Contributor
timestamp: February 24, 2021, 12:32:35 am
content: Quote from: AVGresponding on February 23, 2021, 07:04:35 pmYeah!Before it had a fancy name, people who built Radio Transmitters with serious "biteys" available inside, knew that the default position of a safety related relay or contactor was "OFF", & anything that could otherwise allow personnel contact, or fire, was "safety related".

author: beanflying
author_rank: Super Contributor
timestamp: February 24, 2021, 12:50:04 am
content: Quote from: SilverSolder on February 24, 2021, 12:24:36 amThere is but the point is they lied and the UK Authorities didn't do their job of inspection to their rules.Quote from: Syntax Error on February 23, 2021, 05:09:05 pmApart from one Drone as far as I know Dave has had no real background in R/C or UAV use or building. This is is a large part of the failings of this abomination as it was put together in a rush by people without background or relevant experience. Having a specific what would be a largely speculative video redesigning a safety system for part of a larger unknown one would be of little use without this background.Even in off the shelf R/C level gear most have a throttle off functionality on loss of signal built in and a lot of them have had this for a few decades that shut the Engine throttle servo. This was generally to slow down the likely crash to come but I have seen up way to close a 3kg Helicopter going into this shutdown to then reboot and plow in at full throttle 10m away. This was the result of a fairly early Spread Spectrum receiver having a reboot time of nearly 1 second after a number of dropped frames was detected. 1 second at 120 km/hr (estimated at the time) is about 30m add to that any chance of a recovery by the pilot and you are twice to three times that. Two of us got lucky that day and we were at the time the 30m back from the flight line as per the Oz RegulationsThis 95kg UAV capable of 160km/hr (their claim) is capable of covering 40+ m/sec even when shutdown as a straight ballistic projectile. If it is at altitude that potential distance travelled in this state will be greater so a shutdown is NOT an appropriate safety in particular when being used near an Audience. At a minimum a ballistic parachute should have been required as part of any failsafe system.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 24, 2021, 12:58:53 am
content: Quote from: Cerebus on February 23, 2021, 11:59:59 pmIt could also be a garbled version of the true fact that ordinary series DC/universal motors can suffer destructive runaway, if operated at full voltage without load.Apart from us being taught that, I remember a series motor flying apart, with bits zipping past my ears, when our Tech lecturer forgot to turn the variac down prior to demonstrating one of them to the class.I understand that BLDC motors are different, buttheywon't understand!Quote

author: Kean
author_rank: Unknown
timestamp: February 24, 2021, 02:40:39 am
content: Quote from: bd139 on February 23, 2021, 09:48:37 pmMaybe that is all they could afford after spending most of their budget on the airframe. The airframe that is now a pile of scrap metal (or scrap carbon fibre?).

author: Syntax Error
author_rank: Frequent Contributor
timestamp: February 24, 2021, 05:11:17 pm
content: Quote from: beanflying on February 24, 2021, 12:50:04 amActually, I was not specifically thinking of failsafe devices in UAVs, but the wider implication of failsafe-by-design inallelectronic engineering.As NANDBlog aptly says:Quote from: NANDBlog on February 23, 2021, 10:22:48 pm[Via Google] the IEEE has a working group on a " Standard for Fail-Safe Design of Autonomous and Semi-Autonomous Systems"Quote

author: bd139
author_rank: Super Contributor
timestamp: February 24, 2021, 05:18:48 pm
content: Hmm standards...1. Experts get together and define a working group.2. Experts eat a lot of biscuits and drink a lot of tea.3. Eventually out pops a standard revision.4. Consultancies align around that standard and certification of it.5. People hire the consultancies to fix their product lifecycle and certify it.6. Lots of paperwork gets filled in.7. Some very small process changes are made which allow the existing processes to continue almost unaltered.8. Product falls out of sky anyway9. Vendor points to consultants.10. Consultants point to IEEE.11. Regulator shrugs12. GOTO 1Sorry just got years of being burned by ISO crap which turned into a way of hiring from rock bottom in the pool and paying consultants to certify away all the gaps and incompetence. And don't tell me that doesn't happen in aviation - look at Boeing.Only thing that actually improves standards is hiring clue and body counts unfortunately. Every safety process has a death behind it because objectively no one gives a fuck until they have to shovel a corpse away.Edit: I suppose this is why aviation has higher standards than general software actually. One has a body count and one does not.

author: janoc
author_rank: Super Contributor
timestamp: February 24, 2021, 05:26:54 pm
content: Quote from: Kean on February 24, 2021, 02:40:39 amThat looks more like someone who knows how to build model aircraft/multicopters realizing that they also need a control system and the stock RC airplane/drone fare wouldn't do for a vehicle of this size."Oh but I have a nephew who is really good with Arduinos!" - so the dude came, ordered a bunch of cheap parts from AliExpress and made it "work". Given the construction it was actually a pretty remarkable achievement that it worked as well as it did.Fortunately nobody has died.

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2021, 05:27:46 pm
content: Quote from: bd139 on February 24, 2021, 05:18:48 pmThat's a very British view of standards committees. You need to get out more. In some places they use a radically different approach where they substitute coffee for tea, and cookies for biscuits.

author: bd139
author_rank: Super Contributor
timestamp: February 24, 2021, 05:28:50 pm
content: That’s fair. I worked for a US defence company. We had donuts and coffee

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2021, 05:30:20 pm
content: Quote from: bd139 on February 24, 2021, 05:28:50 pmYou must have started late. The early starters get blueberry muffins.

author: Cerebus
author_rank: Super Contributor
timestamp: February 24, 2021, 06:41:06 pm
content: Quote from: bd139 on February 24, 2021, 05:18:48 pmAlso the people who end up going around all the standards committees and meetings are often effectively seconded full-time to them because they're the fools who are a pain-in-the-arse and/or too dangerous to have around the office/lab but aren't actually bad enough that you can fire them. It makes them feel important and it keeps them out from under your feet.Weirdly the organizations that subscribe to this practice of offloading their problem staff into the standards treadmill are often the ones that are most enthusiastic about using the same standards that they know have been constructed by a committee of offloaded problem staff. Go figure!

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2021, 06:48:43 pm
content: Quote from: Cerebus on February 24, 2021, 06:41:06 pmIt depends on the standard. Companies put their very best people into some standards groups, in an effort to develop new IP, and work to make it essential to a new standard.

author: Cerebus
author_rank: Super Contributor
timestamp: February 24, 2021, 07:11:35 pm
content: Aye, well I did say "often" not "always".I've been on a standards committee, so obviously sometimes people send their brightest and best!

author: Syntax Error
author_rank: Frequent Contributor
timestamp: February 24, 2021, 08:53:09 pm
content: Quote from: bd139 on February 24, 2021, 05:18:48 pmSafety methodology was not really a thing until the advent of the railway age in the early 19th century. As soon as locomotive boilers began exploding and trains began running stop signals stuck to go (fail-safe advance), owners realised they could kill rail workers with impunity, but not their middle class newspaper reading fare paying passengers. It just didn't look good.I agree, ISO consultants are not often worth their carbon footprint, but the certificates they give out give managers a warm fuzzy ISO2001 glow. Even if those managers don't or won't listen to the safety concerns of their own staff.

author: Refrigerator
author_rank: Super Contributor
timestamp: February 24, 2021, 09:00:50 pm
content: I'm only interning at a company right now but i've already had the opportunity to witness someone else's incompetence that resulted in a run of production boards that are barely over 100mm across but have like 8 bodge wires running every which way all across each one of them.In the pic attached (snip of the schematic) you can see arrows and all kind of scribbles that mark out where the bodges are supposed to go. That's not to mention that the schematic itself is a raging dumpster fire.Needless to say i, together with my friends, had a good laugh at this schematic and i hope i don't have to fix it, but if i had to i'd start anew. The fact that this got the OK to be sent off to production is incredible, hilarious and sad at the same time.

author: bd139
author_rank: Super Contributor
timestamp: February 24, 2021, 09:01:16 pm
content: Quote from: Syntax Error on February 24, 2021, 08:53:09 pmIt's a good analogy and one I use occasionally actually. I have a powerpoint stack about designing in "operational readiness" (mostly because it sounds better than "stop slinging turds over the fence") i.e. fail-fast, fail-early, assertions, logging, debugging, testing, fuzzing, safe concurrency models, event correlation, preventing cascading failures etc. It has the attached picture as the the third slide which always solicits a few sniggers

author: Bicurico
author_rank: Super Contributor
timestamp: February 24, 2021, 09:06:53 pm
content: Quote from: Refrigerator on February 24, 2021, 09:00:50 pmAre you sure you are allowed to post that schematic?I would fire you on spot...Regards,Vitor

author: tszaboo
author_rank: Super Contributor
timestamp: February 24, 2021, 09:18:33 pm
content: Quote from: Cerebus on February 24, 2021, 06:41:06 pmI've a very different experience with safety standards. I've went through a lot of publications in the topic, trying to get a clue on how to design intrinsically safe circuits, or how to make them better. I've came across a test lab in Germany,(PBT), I believe they are responsible for some of the models for the standard. There has been countless hours of testing, and blowing up stuff (literally) trying to determine the safety limits, so something blows up in a lab, and not in a chemical factory. Imagine blast proof test chambers with 100mm thick steel walls, filled with explosive gasses, and come circuit in it with intentional faults, tested tens of thousands of times.I'm talking about people working on the same subject for 20+ years.So yeah, I'm sleeping somewhat better this way. I followed the standard, and little Lizzie's father didn't get blown into little pieces, together with his 12 coworker, because there was a short circuit by a loose wire in something I've designed.

author: Ian.M
author_rank: Super Contributor
timestamp: February 24, 2021, 09:24:14 pm
content: @bd139,I was inspired to google that one!https://en.wikipedia.org/wiki/Montparnasse_derailment

author: Refrigerator
author_rank: Super Contributor
timestamp: February 24, 2021, 09:25:43 pm
content: Quote from: Bicurico on February 24, 2021, 09:06:53 pmIt's only a small snip of the part where the relays go and i made sure the company name would not be included but i can remove it if it's such a bad thing.Edit: changed the pic.

author: Saskia
author_rank: Super Contributor
timestamp: February 24, 2021, 09:41:53 pm
content: You should. Posting stuff like this would get you fired immediately and escorted out at our company as well.Posting this actually is a great example of complete lack of risk awareness and utter negligence towards your company intellectual property and would justify not offering you a permanent position. You should have spoken up and raised your concern about lack of qa internally and submitted a better schematic for consideration

author: bd139
author_rank: Super Contributor
timestamp: February 24, 2021, 09:45:35 pm
content: Quote from: Ian.M on February 24, 2021, 09:24:14 pmYes a fine example of human error that one!

author: Cerebus
author_rank: Super Contributor
timestamp: February 24, 2021, 10:09:58 pm
content: Quote from: Saskia on February 24, 2021, 09:41:53 pmWouldn't if you worked for me. There's not enough for any of the substance of the schematic to be identified, the company can't be identified, neither can the individual. The risk of IP leaking or of repetitional damage is non-existant.

author: PlainName
author_rank: Super Contributor
timestamp: February 24, 2021, 10:23:58 pm
content: QuoteSo where would one turn for info if not a big name standard?

author: Saskia
author_rank: Super Contributor
timestamp: February 24, 2021, 10:25:55 pm
content: @Cerebus different industries, different standards.Fair enough.

author: bd139
author_rank: Super Contributor
timestamp: February 24, 2021, 10:29:12 pm
content: Quote from: dunkemhigh on February 24, 2021, 10:23:58 pmWell there isn't really. If someone wants you jump through the hoops you have to or die. So I refer to my previous list:6. Lots of paperwork gets filled in.7. Some very small process changes are made which allow the existing processes to continue almost unaltered.

author: Refrigerator
author_rank: Super Contributor
timestamp: February 24, 2021, 10:31:31 pm
content: Quote from: Saskia on February 24, 2021, 09:41:53 pmWhen i came people were already knee deep dealing with the mess the previous guy caused and the issue was well known.Also there was no time to re-spin the boards not to mention i don't know how this thing works and why are things connected such way, chances are i would only cause more trouble by submitting a rushed design with a lack of deeper knowledge of where the board goes and what it does.Not to mention i would be putting my nose into other peoples business completely uninvited, while i have other more important things to do. Imagine some newbie intern submitting a schematic with board design to you implying what you have been producing is trash.Also i cropped the image even more to just the relays and noticed the 1N4148 flyback diodes on the 24V relays.

author: Saskia
author_rank: Super Contributor
timestamp: February 24, 2021, 10:43:13 pm
content: Still you should be very careful discussing this outside your immediate work environment without having explicit permission to do so.

author: Cerebus
author_rank: Super Contributor
timestamp: February 24, 2021, 11:06:03 pm
content: Quote from: Saskia on February 24, 2021, 10:25:55 pmNo, not really. The industry doesn't matter, loss of confidential material or loss of reputation are risks in all industries. It's the difference between places that like to have long lists of absolute "thou shalt not" rules, with no leeway, and taking a sensible approach that recognises that not all information is sensitive. It's a question of degrees. The details of the capabilities of the latest high tech weapon developed for the military are secret and deserve to be treated as secret, the colour of paint it's painted with isn't conceivably sensitive, but the quantity of paint needed to paint onemaybe sensitive information. Firing someone summarily for the least leaking of inconsequential secret/confidential/proprietary information merely because someone in authority has decided to deem all informationno matter how inconsequentialas secret/confidential/proprietary is classic authoritarian bullshit.

author: vk6zgo
author_rank: Super Contributor
timestamp: February 25, 2021, 12:57:22 am
content: Quote from: Saskia on February 24, 2021, 09:41:53 pmIt's not that simple!"Intellectual property" in hardware is, in my experience, a pretty rare thing.It is often a bullshit excuse to hide the fact that most stuff is just "public domain" material, copied directly from the component manufacturer's Application Notes, or sometimes, stolen from a competitor.I've worked for a company which wouldn't allow Techs to see the schematics, quoting "IP concerns", which made trouble shooting the prodigious number of stuff ups they made extremely difficult.When they finally let us look at the schematics, the amateurish design was apparent.In just one instance, PWM control signals were integrated, passed through a couple of Op Amps, then fed to an ADC.Fair enough, in a way, as the prototype, designed by a couple of "gifted amateurs" used pots to supply the control functions, & as a quick "bodge" to allow the use of the proper PWM signals it was forgiveable, but it continued to be done for years on production units---------what the hell did we have EEs for?Meanwhile, their physical security was almost non-existent.You could have broken into the place with a sharp fingernail, set up a keystroke logger on one of the Programmer's PCs, or even something as simple as a small TV camera looking at the keyboard, (the only real IP was the software), then returned the next night to play with the PC, now having the passwords, etc.They even lost a company laptop on one occasion!Meanwhile, " Occupational Health & Safety"? ---What's that?The main Production area was a bunch of temporary benches, all powered by a long "daisy chain" of power boards.We had to build stuff into quite large metal units of varying shapes, depending upon the model we were making, with a bare minimum of tools.Oh, Yes, the "Chief Engineer" loved to "rabbit on" about them achieving ISO status!They hated anyone with experience in the real world of Electronics-----tell them that they were doing something which was unsafe, wasteful of time & money, or anything else, & you became "an enemy of the people".As an "old fart" with extensive experience with equipment made by real manufacturers, I "opened my fat mouth", & became the aforesaid "enemy".The dumb bunnies couldn't even sack me properly-----they asked me to stay on for a while, till they could find a replacement, then promptly forgot they had fired me!I stayed on till I couldn't stand it anymore & quit!My feeling, from this experience, is that much Electronics manufacturing in this country is at the "bottom end of the food chain" in QA.Sorry about the rant, but thinking about that place still makes "steam come out of my ears!"

author: PlainName
author_rank: Super Contributor
timestamp: February 25, 2021, 02:48:35 am
content: QuoteWho decides the degree is large or small?Actually, it's a question of whether or not an NDA was signed. If he did sign one thenanyunauthorised release is a transgression. If he didn't then he can technically show us whatever he fancies (but his continued good relationship with the firm may have a bearing).

author: Cerebus
author_rank: Super Contributor
timestamp: February 25, 2021, 03:15:01 am
content: Quote from: dunkemhigh on February 25, 2021, 02:48:35 amWhat it all boils down to is whether one follows the "keep 'em scared" school of management, where all infractions are black and white and you treat your employees as the enemy, to be legislated against, or the "we're working together" school where you expect your staff to act like adults and treat them accordingly. My experience is that one works well, and the other just eventually breeds resentment. An unidentifiable corner of a schematic doesn't reach the threshold of treating it as a breach of confidentiality, even if technically it is, albeit a trivial one. De minimis non curat lex.

author: PlainName
author_rank: Super Contributor
timestamp: February 25, 2021, 03:36:22 am
content: QuoteIt is, then. Whether or not any action would be taken isn't relevant except to the person who is taking the risk.On topic, do you run off a lengthy paragraph in this fashion to explain away why some particular sarfety aspect isn't actually that important in the greater scheme of things and probably wouldn't get triggered anyway? Or is it only your word that you like to play fast and loose with depending on how important it seems to you?

author: Cerebus
author_rank: Super Contributor
timestamp: February 25, 2021, 03:58:26 am
content: Quote from: dunkemhigh on February 25, 2021, 03:36:22 amThat's a completely meaningless nonsequitor. Why should there be any link whatsoever between my attitude towards managing people and my attitude towards safety critical systems. And talking about me playing fast and lose with my word implies that I'm a liar, please do not use language like that without any provocation or reasonable basis for doing so whatsoever - it's insulting and one can only presume that it's meant to be deliberately provocative.

author: EEVblog
author_rank: Unknown
timestamp: February 25, 2021, 07:56:44 am
content: Quote from: Kean on February 22, 2021, 09:48:32 amYeah. That's ok for a proto platform for bench testing or whatnot, but not airworthy.

author: Simon
author_rank: Unknown
timestamp: February 25, 2021, 08:02:22 am
content: Can we calm down please.

author: bd139
author_rank: Super Contributor
timestamp: February 25, 2021, 08:12:34 am
content: Quote from: EEVblog on February 25, 2021, 07:56:44 amI dunno about that. Think even a Bob Pease prototype was tidier

author: Ice-Tea
author_rank: Super Contributor
timestamp: February 25, 2021, 08:18:07 am
content: Quote from: Refrigerator on February 24, 2021, 10:31:31 pmOut of curiosity: what's your problem with a 1N4148?

author: Ice-Tea
author_rank: Super Contributor
timestamp: February 25, 2021, 08:18:58 am
content: Quote from: bd139 link=topic=271234.msg3481536#msg3481536Cover of an excellent album. That too