Looks great. An enhancement to the kill switch might be to make it a normally open relay which needs to keep receiving a command to keep it closed. So that when power or communication fails it stops instead of requiring power to activate the kill switch.
I'll be sure to keep your wisdom in mind next time I have to reset the way too conservatively sized circuit breaker integral to the contractor that runs in my fume extractors.
Damn near anything can kill you. Context matters. In most cases a consumer lawnmower should probably have a deadman switch. Plenty of people have been hurt or killed over the years by poorly thought out fail "safes". It's easy to make low effort online comments about safety but when someone comes along and re-uses your widget in a use case you don't expect your assumptions may not hold. You rarely have the context to determine what's safe unless you know the end situation in which the equipment will actually operate. For a lawnmower you do. When you start generalizing your control system and applying it to other stuff you don't.
Absolutist rules of thumb are worth what you pay for them.
This is really pedantic. The rule is any system that risks serious harm to a person in the course of normal operation should be fail-safe, not fail-dangerous.
Examples include stuff with blades, hammers, or swinging arms moving at high speed or with great force.
> The rule is any system that risks serious harm to a person in the course of normal operation should be fail-safe, not fail-dangerous.
I used to work in a Chemistry lab, one in which one of my lab-mates once had a explosion while he heated something which wasn't what he thought it was.
I was the guy who phoned for the ambulance (and got the fire service included for free, but maybe that makes sense if you work in a lab). I went to the front entrance to meet the firefighters as instructed, after identifying myself they asked me "do you have anything dangerous in your lab?"
I was probably still high on the adrenaline (there had been a fairly loud bang and the glass side windows of my colleague's fume hood were blown out) but I recall being unable to answer that question. I think I eventually said "Yes, of course we have dangerous stuff, you have anything particular in mind?"
> * I'll be sure to keep your wisdom in mind next time I have to reset the way too conservatively sized circuit breaker integral to the contractor that runs in my fume extractors.*
You might enjoy the NEC section on fire pump systems. It's a complete flip from the rest of NEC, requiring design around "Keep the fire pumps running at all costs, even if you're in the process of melting down the windings." Separate wiring conduits, handling full locked rotor current indefinitely, etc.
The logic, reasonably enough, is that if the fire pumps are running, you probably have way, way bigger problems that will be made worse if your fire pump system trips off to protect the wiring.
On that topic, the Cathode Ray Dude posted a really interesting video yesterday talking about battle-shorts, a mechanism used to circumvent power relay fail-safes in military equipment. There were some interesting comments about other cases like the fire pump systems you mentions.
What is this screed even trying to say? "Someone might reuse your failsafe in a way that actually makes it dangerous"? Then it's not a failsafe anymore and the second designer is an idiot. Like with the firehose example, it isn't the pumping that will kill you it's the not-pumping, therefore your failure state should halt the not-pumping.
One of the complications of this is that it's very hard to hold the switch on certain types of terrain. Objectively, well over 80% of that terrain is situations where you have no business running a lawnmower in the first place, and so 'good!' is mostly the correct response to such complaints. But it's still a pain in the ass in other situations, like cornering past bushes.
Me, I just don't have grass anymore. Fuck grass. It's a bunch of bougie bullshit from a line of the French Aristocracy who ultimately wound up with their heads in baskets. Maybe we shouldn't be copying them.
One of the complications of this is that it's very hard to hold the switch on certain types of terrain
I've never used a mower fitting that description. On all of mine the safety handle runs the entire length of the push handle and you have to essentially let go of the mower to disengage it.
No mention of how it handles obstacles; sticks, rocks, holes, small animals, etc. I mowed lawns for several years as a teenager using riding mowers similar to this. I can't count the number of times I had to stop, get off, move a stick so it doesn't jam the blades, move a rock so it doesn't get flung into a nearby window...or even just slow down because the grass was too thick for the mower to handle. It strikes me as having some of the same issues my robot vacuum has. When I have to constantly get it unstuck from a lamp cord or a loose rug, it starts to become more trouble than it's worth.
I had my share of pain with those obstacles. That was my first thought when I saw this project.
The workaround, which I didn't implement yet, is to build a smooth and clean garden. Of course branches fall, ants build, all sort of animals dig, bushes grow id you give them a couple of weeks at the wrong time of the year, etc.
The neighbor lady toss rocks on your lawn from working in her flower bed. Neighbor kids leave toys, tennis and golf balls and... claw hammers!!! (forgotten in the grass after building their secret day fort in your back yard). Wine bottles from the other neighbors garden party. A hiking boot from... I have no idea!!! And don't forget stuck sprinkler heads. Spray paint cans from the local juvenile delinquents... On and on...
I love the idea of this because I hate lawn maintenance. But the idea of letting software I wrote run around with whirling blades of death underneath of it would keep me from doing it.
I totally agree! Mower safety was also one of my worries once. It can be deadly even without software controlling it. A few days back in Poland a mower threw a piece of wire straight into a boy's heart (the kid is all right now). That being said, there is no way for the operator to constantly monitor what is happening around the mower. A set of sensors and software can be better at it. We can install cameras and LIDARs all around the mower and take care of safety better than humans do.
There are challenges though:
1. You need to design the system in a way it fails safe. There is no explicit norm on how to do that yet. We can adapt existing norms from machine and robot safety for that purpose, but we risk missing something.
2. All the specification efforts right now are going in the direction of humans supervising software. The RC-controlled/autonomous mower is supposed to be always watched by someone. Firstly, humans suck at supervising stuff, it is a very boring and frustrating task, during which it is easy to get tired and lose focus. Secondly, people will quickly find a better task to do in the meanwhile: trim the hedge, do the detailing, do some weeding, while the mower is doing fine :)
3. Safe vision systems are expensive. It is hard to support a 360 deg. field of view for both cameras and LIDARs at a competitive cost. There is a huge temptation to reduce the BOM cost to compete with human labor.
Now it is time for a shameless plug: personally, I am involved in making an autonomy kit for z-turn mowers. It is not an easy task.
Yeah, losing focus while a robot drives is impressively easy even if you know you need to watch for safety. For some reason it's just so easy to trust them once they work even for just a little bit. It's part of the reason "level 3" robotic vehicles won't pan out.
Can also confirm about the zero turn mowers. Recently switched jobs from automating cars/tanks to mowers myself. At the very minimum mowers have way tighter power and space constraints plus hydros are not easy to control well automatically.
A solution could be to just secure the area well enough to guarantee that 1) an uncontrolled machine can't escape and 2) people don't enter the area. Then you don't particularly care if the machine is "unsafe" if there's no way it can harm anyone.
That's the approach most industrial robots take - instead of trying to deal with humans and not hurt them, just make sure there are no humans within reach of the robots.
That's harder than it should be. No amount of asking my neighbors has kept their kids out of my fenced lawn to retrieve their soccer balls. Which is actually an issue because one of my dogs is not particularly friendly. I'd gladly kick the ball back over if they just knocked on the door. We're not a neighbor-hate-neighbor situation, we actually get along quite well, but kids will be kids.
Asking isn't enough, but proper fences should both make it impossible to get in without significant effort and also do a good job at containing the machine should it try to run away.
It's up to you to run the numbers whether the cost of securing the area is less than what you spend (in terms of time/inconvenience/etc) manually mowing the lawn.
That works great in industry, indoors. Outside you are going to have animals. I have a few acres that I mow and find new nesting animals pretty much weekly. Some of them can fly, and the migratory ones (which I do not personally know how to spot aside from a few recurring visitors) are legally protected. Sometimes they run away as they approach, sometimes they want to defend. Either way I do my best to go around and leave them their patch.
We had the same problem of grass growing heedlessly but solved it in a different way. We got a bio-fuelled autonomous self-propelled lawn management solution which intelligently solves the problem without the need for any programming, all it needs is for us to demarcate the area in need of maintenance with some special white band. Even though it is more than 30 years old it does the job just fine. It doesn't just cut the grass and weeds but processes them into fertiliser as well. It can be used autonomously but it is also possible to control it although the limited carrying capacity limits ride-on control to smaller persons - children up to the age of about 10.
It is called 'a horse' - a small-ish Welsh mountain pony to be exact.
I don’t know if it helps but the super cheap flysky rc system (common budget option on rc aircraft) has failsafe functionality built in. You configure which outputs should be in which state during failsafe and it can be triggered by being out of rc range (i.e. experiencing unexpected interferance) or by toggling a switch to select failsafe deliberately.
Cool project, but why mow it all in the first place? Do yourself and absolutely nature a favor and let it grow. We need every patch of natural land we can get, as biodiversity and insect populations are continually decreasing.
Mow some patches for the humans (because standing in a buggy tall field is just no bueno), but leave the rest for nature. Rent or borrow some goats or sheep if you really want it kept lower; at least you'll end up with richer soil that way.
Personally, I don't want to be fined by the city. It's a poor reason but a sufficient one.
I maintain a lot of habitat in the back, but the front has to stay high and tight. My neighbors prefer it as well, you can change a culture but should think carefully before defying it.
I completely agree with your point - pretty much everyone is now properly aware of the climate crisis but for a bunch of reasons biodiversity crisis doesn't ring a lot of bells let alone people are willing to do anything about it. However: depending on where you live not mowing at all turns your meadow into a rough wilderness with only a couple of plant species (think nettles+blackberries) in no time, and later on into forest. Main reason being nitrogen deposition leading to those species simply outgrowing the rest, as is the case for e.g. quite a lot of areas in western Europe (visuals in [1] for example).
So as far as biodiversity goes: there's enough of the typical 'no mowing' vegetation already whereas ecosystems like flower-rich meadows are in decline. Currently and practically for laymen this can only be countered by mowing and removing cuttings. Depending on soil type and what's in it fertlizer-wise about twice a year. Preferrably, as you mention, still with mowing patches instead of everything at once in order to maintain some habitat for the fauna. Still a lot less time and money consuming than maintaining a lawn.
In commercial farmlands, even in "progressive" countries like the Netherlands, the insect friendly unmowed zones are present but very minimal compared to the commercial farmlands.
By my estimation, the unmowed insect strips are 1/50th or less than the crop areas.
It is good to see that roadside zones are being allowed to grow a bit taller. As drivers, it's actually a negative because it makes seeing around curves more difficult, but it absolutely results in more wild flowers and insects. It's quite beautiful too.
the insect friendly unmowed zones are present but very minimal compared to the commercial farmlands
It's also quite debatable whether they're that friendly. Leaving it grow then mowing everything in one go and leaving all cuttings, as I see often in my neighborhoud, is more like creating a death trap for insects. Also because these zones are almost always subsidized, but not mandatory, so if the farmer feels like it they can just be removed again. One thing these zones are often good for though is catching mud streams from erosion. Ideally there would be no such erosion of course, but at leasts it provides some prevention of soil just washing away.
On a brighter side: if I got it correctly Europe is working on legislation which is going to make it mandatory for farmers to dedicate x% of land to nature. Not just zones with grass, also line elements with bushes etc. Essentially restoring what the land looked like here the past centuries before agricultural industrialization kicked in.
As drivers, it's actually a negative because it makes seeing around curves more difficult,
Pretty sure communities or whoever owns the road are allowed to mow curves and other spots throughout the year to guarantee visibility. But yes, there's quite some potential there (there, and in gardens): the total amount of area makes it well worth it. Still going to take a while before it gets done properly though (again: mowing everything in one go is quite detrimental).
> legislation which is going to make it mandatory for farmers to dedicate x% of land to nature
Considering how badly the Dutch farmers have behaved thus far on any issue which “threatens” their way of life (profit maximization), I can only imagine how they will respond to this.
Maybe they will finally cross a line so bold that the Dutch government will stop bending over for them.
That's the thing about nature. It has immensely complex programming that we don't understand. Often a "plague" of one thing exists to rebalance another thing.
If unmanaged nature does run wild with one or a few species, at some point they overstay their welcome and get rebalanced.
Of course the final equalizer is fire. And that's something that we as humans really dislike, because it burns our work (and homes and sometimes even us) down. So we prevent it. But completely left to itself, nature does tend to stabilize after some period.
As for western Europe, I live in Netherlands. The nitrogen problem is entirely manmade (animal farming waste). Were we to stop ranching at such high densities and producing unnatural levels of animal waste, the nitrogen levels would not be nearly so high.
I have also lived in plant farmland areas in the south of Holland, and we have plagues of burning weed that grows. But it turns out, that plant grows in places with excess nitrogen. It feeds on it and eventually draws it out of the soil. After a few years, that "weed" stops growing and the soil nitrogen levels are more normal.
At this moment I am in central Portugal trying to grow some trees. The thorny vines (blackberry brambles I believe, but I just don't keep up with the names) are a huge problem. However, they provide benefits in dry soil because they grow very well, provide shade, provide food for foraging animals, and help prevent soil erosion when the rains finally come.
Nature doesn't seem to be concerned with human comfort. I f*cking hate the vines, but I do see their purpose.
After some years of study of permaculture and actual experiments, plus a decent amount of reading, I think our best hope as humans is to develop high efficiency vertical farms and to keep our actual earth footprint low... and to start devoping subterranian habitation.
On the last point, it's really a wonder to have a home which stays around 68F all year. Heat it up just a little and it is cosy. It is fire-proof, ultra efficient, and it can still be light with skylights and a south/west facing opening.
Honestly, for a fraction of the mental energy we spend on designing scalable software systems, we could make livable earth-friendly human food ad habitation systems. This is not rocket science; after all, primative civilizations already figured out some of these things.
If unmanaged nature does run wild with one or a few species, at some point they overstay their welcome and get rebalanced.
The problem being that in the example I made, this balance is still man-made and not really natural. I.e. if you'd done the same 500 years ago, you'd get a balance with more than a few species. If you'd done the same like 5000 years ago (give or take), things would be even more different because there were still large flocks of wild grazers around.
After a few years, that "weed" stops growing and the soil nitrogen levels are more normal.
Except the deposition keeps on going, so depends on what 'normal' is the reference compared against.
Adding to this: depending on where you live, the rodent issue is made worse by the vipers they attract. I generally don't mind snakes, rat snakes are actually quite nice, but I think most people don't want to worry about a rattlesnake nipping their heel when they step out their front door. This is made worse by the selective pressure humans place on rattlesnakes to discourage rattling (those that rattle get noticed and killed.)
I think there are probably better ways to address this problem than mowing grass right up against your house though. Ringing your house with mulched gardens or even gravel patches (particularly french drains, in areas prone to flooding) is a good alternative, presuming you don't have a HOA forbidding it..
There is a concept of zones. You make zones 0 and 1 very human friendly. Beyond that you gradually transition from aesthetic and food growing toward wild nature.
I'm not suggesting you wade through waist high weeds as you walk out your front door. But if you looked at the photo of the original post, you would see the plot being mowed appeared to be just a pasture well beyond habitation.
Depending on where you live those rodents won't do any harm though. Or simply leave again because the cannot find food, which is like the #1 thing to deal with in case of rodents. Moreover you'd need a serious amount of 'deadzone' around your house before rodents won't cross it, no? It's not like they only can cover distances of few metres. All in all, this type of claim should be backed by research :) Curious if there is any.
> Depending on where you live those rodents won't do any harm though. Or simply leave again because the cannot find food, which is like the #1 thing to deal with in case of rodents.
> All in all, this type of claim should be backed by research :) Curious if there is any.
Yes, any evidence for your claims would be appreciated. Are there places where mice/rats aren't considered a disease vector?
Are there places where mice/rats aren't considered a disease vector
All species? I actually don't know. But with 'depending on where you live' I also menat situations like mice entering your unused basement etc.
Anyway: I'm mainly questioning whether 'long vegetation around my house means more chance of rodents in my house' is something general. Also because it's not my experience. Then again I don't live in, say, Australia.
> situations like mice entering your unused basement etc.
This is a bad situation, if anybody ever goes in that basement for any reason ever, they're at risk of catching numerous diseases from the rodent feces they stir up into the air by walking around. Hantavirus is spread this way, and Hantavirus pulmonary syndrome kills about a third of the people who catch it. There is no reason to accept this risk if you have any other choice.
Hauntavirus is no joke. I knew a piano tuner who got it, and it was not pretty. Mice droppings in an old upright, ironically in a house with a very poorly kept lawn. He was tuning it for a lady that was trying to sell it so she could move out.
That's some great work and a really good write-up.
I could see practical uses well beyond a lawn mower. This would be very handy in really hot or cold weather with just about any large tractor that is not enclosed and does not have air conditioning or heating. No more breathing exhaust and no more being exposed to the weather. For large farm equipment one would still need a person near by in the event things get tangled up in the equipment such as barbed wire snagged up into discs but that is an acceptable trade-off to me.
As a bonus, no more being locked into newer tractors. If I could put this remote control on my 1947 Fordson tractor it would now be put to work with automation and for fun the neighbors would think it's a ghost tractor. Probably the tricky part is dealing with the stiff clutch and finicky gear shifting. I imagine it would get some looks from the tourists passing by on the highway.
I wanted to do the same with but with a large agricultural tractor.
I think we are nearing the point where a camera can monitor my body movements and mimic it fairly accurately in a robot. Combine that with gloves for hand tracking, VR goggles, audio headsets and maybe haptic feedback and we can effectively have remote experiences.
Once that’s the case, you put a robot in a tractor seat; add a bunch of cameras (for VR), microphones (for audio), and a couple robot arms with humanoid hands attached (https://www.psyonic.io/ability-hand).
I can then remotely control the tractor in VR space, but have it operate 100 miles away
I understand why you would do it, but using robot arms to control another robot seems like a lot of accidental complexity. Surely there has to be a generation of tractor that's new enough that most functions are exposed on CANbus but old enough that it isn't locked down yet?
The lockdowns are only for the user-facing diagnostic port. I'm not aware of any vehicle that uses encryption & authentication on the inner buses. Your only challenge is to reverse-engineer the meaning of the messages.
Some modern vehicles with FlexRay have full-bus encryption, and very modern CAN systems usually use HMAC for security sensitive stuff like immobilizer and key commands. I think ADAS systems will probably use similar in the coming years as vendors become more concerned and upset with system tampering.
But, yeah, overall, most vehicle control systems are far less evil than people seem to think. I think part of the issue is that the "vehicle hacking" community have managed to massively over-hype basic protocol / message reverse engineering.
What if you ripped out all the control electronics, leaving only the actuators, and replaced the control circuits with off the shelf parts? I expect it might cost a pretty penny, but it should be doable right?
At least for engine management that's definitely doable, there are off-the-shelf ECUs for race/custom cars that are meant to be used like this (configurable via USB so you can tune every parameter).
For everything else you will most likely need to go custom but it's absolutely possible.
I think the biggest problem you'd run into is that people are cheaper than your automation. A 16 year old will run your tractor all day for minimum wage.
I understand that this is a hack project (so doing for the sake of doing).
But if I were going to create an autonomous/RC anything, I would start with Ardupilot [0], which has off-the-shelf support for a lot of what's implemented here, like mapping, waypoint management, and even state estimation/control. You can buy a computer that can do all of this for pretty cheap.
Overview of converting an old lawn tractor to a remotely controlled and immersive drone-like experience. The tractor gets equipped with video cameras, sensors, microcontrollers, wifi, and experimental augmented reality feature. A web interface with a head-up display and a gamepad allows for the control of the tractor from any device.
You're laughing but this will probably happen, together with large scale automation. Labor costs are still a significant portion of costs [0, see "Labor Cost Share of Total Gross Revenues"].
That is awesome. I have wanted to do this for an electric mower. And maybe eventually train it to drive itself with ML. You could even start a service to cut yards and use the public records of the lots to set a boundaries for the yard.
I would definitely buy a Roomba for my lawn (assuming it worked well). Obviously more safety concerns than a vacuum cleaner, with the spinning metal blades and all, but seems doable.
Existing lawn robots still mostly rely on a buried cable to form a boundary-line. The next generation vision/lidar/gps systems are clearly in development but not commercially available in the US (the Segway NaviMow is available in Europe).
This year was the tipping point for the US market, they weren't readily available until late summer. I'll have a (ground) wireless lawn robot next year one way or another, it would bring me more satisfaction to build one but that doesn't mean I'll actually do it.
That's new — but those are still $5000 models "designed for professional fleet use", a little on the steep side. I'd give it a little longer for that to percolate downmarket towards the likes of the Navimow which is around the €1500 level.
Now add some armor, machine gun and antitank missile, and it can be used in Ukraine. Ukrainian army has lack of heavy hardware compare to Russia, and there is no way to build it up quickly, and i wonder whether a fleet of cheap light armored remote controlled or [semi]autonomous vehicles can be even a better way to fight modern war.
And of course there is a very close task to mowing - de-mining, and there are already huge swaths of land there freed back from Russia which need demining, and there would be a lot more in the near future.
There are a couple of remote lawnmowers on the market. I'm surprised given what we can do with AI that they are not in wider use. I think I might have kept my house with a small yard if I could have just turned on the iMow and let it go.
They seem really limited at this point. It seems to be out that outdoors is surprisingly inconsistent / has a lot more exceptions than indoors. And even those that use small blades still have a fairly high bar safety wise to overcome.
An early model years ago was able to tip over and keep running before it was recalled ... not the kind of thing you want sitting out on your lawn or the sidewalk.
I have 1.2 acres and run the Husqvarna 450X on my property. The boundary and guide wires were embedded into the lawn itself.
Been running this mower for 5 summers now and little to no issues. Blades need to be changed every 2-3 months depending on conditions. Overall it has saved me probably hundreds of hours on manual mowing.
> I'm surprised given what we can do with AI that they are not in wider use.
If your yard has any relatively steep parts, they fail. I was 100% ready to buy one, only to discover I would still be mowing 30-40% of my yard by hand. I suspect there's a reason most of the demos are on completely flat yards.
The cost varies by cut width (44" is quite a bit cheaper) but yeah, it's very commercial oriented. It's intended for people who need to mow difficult slopes day in and day out.
I'm not aware of really anything capable intended for homeowners besides a good ol' push mower.
There are homeowner-class track mowers that are designed for steep slopes. Our property is pretty hilly so I keep telling myself that when my Husqvarna riding mower finally dies (it's only 16 years old) I'll buy an electric one. Unfortunately that Kawasaki motor just keeps on going and I keep repairing everything else.
What models? I'm curious because my father is looking for a hill mower and most tracked ones I can find don't actually say their max slope which makes me think it's about the usual 15-20 degrees.
Being tracked only really solves the traction part of the equation so they aren't necessarily any better at navigating slopes safely than a wheeled mower.
The neighbor who had one recently moved, but I think it was an Altoz.
I thought the same thing about tracks: only solves the issue of traction/ground pressure, but for whatever reason they're supposed to be better on slopes.
My (wheeled) mower sometimes slips or gets stuck on a particular area on my property because I often don't have enough traction to mow up & down the slope if the ground is not extremely dry: grass is enough to cause slip. And sidehilling causes the upper wheels to lose traction. Perhaps the increased "bite" of the treads compensates for this? Dunno.
Just remember to run it only during the day, so you protect hedgehogs etc. I have seen some pretty nasty damage on hedgehogs based on lawnmowers automatically mowing at night.
I'd replace my entire lawn with some short plant that never needs trimming if I could get away with it. The problem is I'm in an urban area and everyone else with a yard has grass.
to me, this is the future of technology I am interested in. Primarily, small scale technology that can be meshed up together to create awesome results.
