Robotic Lawn Mowers

[Note: this post needs cleaning but a friend wanted to have a quick look to it so...]

I looked at this market back in the 2005, when I was leaving my job to go study (play with?) robotics. After all these many years, I have not seen many (none) of these and I wonder what is the issue. Maybe because I seldom go around on residential neighborhoods? Yeah, that could be the case, because now that I am thinking, I seldom see anybody mowing their lawn, period. The article in Wikipedia says that actually the market is booming.

Long story short, looks like there is actually a lot of activity on this area. Read mostly this and this (with prices). Robots are on the $2k range, they navigate/recharge by themselves, set the perimeter with a wire. Other things to take into account:

Safety

"All of the mowers keep safety as their first priority. The designs above all but totally eliminate the possibility of objects being thrown from beneath the mowers. Projectiles like rocks, sticks and balls launched by traditional mowers result in a large number of serious injuries each year. As of the date of this page being created, there are no recorded emergency room visits at all related to robotic lawn mowers."

Many (all?) robots have also tilt sensors.

Definition of covered area

All of the mowers presently in production use a thin wire placed around the perimeter of the lawn to contain the mower. I think you don't need to bury it but just place it around with sticks. The lawn mowers follow it to provide an edge trim. Self charging models also follow the same wire to locate their docking station." They usually use some kind of dummy algorithm to cover that area...

Notice that the example below from a university uses GPS, IMU and magnetometer for the navigation.

Autonomy/worry free

How autonomous they really are. This includes things like getting avoid getting stuck in corners, walls, trees, water hoses, toys, tree branches, rocks, sprinkler systems, water faucets, poo...Some complains in that area, but in general, they seem to be doing ok.

Also self recharging...

Getting stolen

This has been addressed in general by alarms, lock pin and sheer weight (not so easy to pick it up and run with it).

Price

They are affordable when compared to what you save, but still pricy ($1k-$4k for consumer type), which probably holds people up.

Reliability/Maintenance

Stuff like blade breaking because it hits a rock or... Haven't seen negative comments about that but there is some estimates on the web on estimated maintenance costs per year.

Finish

This would cover the individual cut of the blade or the overall look of the grass. But overall, only saw one negative comment on this.

Noise

Speed

I think this is more a safety issue. Standard travel speed is about 60 feet/minute.

Do they need to collect the grass they cut?

Many do, but no need!!   It is actually better. But make it mulch.

Stop under the elements

Avoid mowing after heavy rains, as this will make mowing more difficult and cause clippings and mulch to bunch.



Then, we just had a look to what is out there:

Traditional mowers: electric weed trimmer and reel mower (~$100). Didn't check the motorized ones. Note: check out the video on sheep getting trained to eat only a given type of grass...

Robotic manufacturers:

Wolf-garten
Honda, http://www.engadget.com/2012/08/21/honda-miimo-robotic-lawn-mower/
Husqvarna
Lawnbotts


There is a robotic lawn mower competition. Found this paper from one of the participants. Also this and this

Overall, feels that the products out there are pretty good. Below a "negative" feedback from customer, but in general, not sure why we are not seeing more...

Feedback:
"again with the buried line crap...   There was a GREAT system available about 5 years ago that used a series of positional sensors outside the home, and software on a PC to manage the mowing process.  Why it this not in use?  Buried lines create dumb mowers, the system I was about to buy (I aborted when my company informed me i was being relocated, and i have not got back looking) not only mowed, it reported back issues in the yard where fill dirt was needed, grass height information (which could indicate water or fertilizer changes are needed in some areas), etc.  Whole thing installed was about $2500, including a secure outdoor charging station and all the sensors.  It needed 1 sensor on the center of each facing wall of the house, and 1 on each corner, and the robot used positional triangulation for movement, which was accurate to the inch.  It also included an edger attachment, and would not just mow, but left clean edges where you told it to. 

These things are glorified roombas still requiring me to manually interrvene weekly in the maintenance of my lawn.  They provide no real value."

A quick thought about using a laser to cut the grass:
http://www.candlepowerforums.com/vb/showthread.php?279367-Laser-lawnmower
http://articles.chicagotribune.com/2001-07-21/news/0107210078_1_clippings-grass-laser
http://grounds-mag.com/news/grounds_maintenance_youve_seen_mower/

How to deal with RSUs

RSU stands for Restricted Stock Units.
Tons of details here.

To the point... Imagine I got 167 Awards/Units Granted. At the vesting date, employer uses 52 to pay the tax and I get to keep the rest, 115 "total shares available (delivered)". In governments eyes, you got 167*$32.18 (share price at vesting)=$5374.06. So, this shows up in your W-2. The brokerage already took some of those shares and sold them to pay for the tax (52*$32.18=$1673.36) and the rest (115) are now real shares at the account, which figure like if they were bought that day (remember this day for the time you sell them). Basically, this is called a Sell to Cover. Probably best would be Same Day Sale but anyhow:
http://thefinancebuff.com/restricted-stock-units-rsu-tax.html

Basically this is like the company giving you the cash at the date of the vesting, so, ordinary income. As this happens in the brokerage that your company has chosen, the whole earnings/taxes are already included in the W-2. So, you got to do nothing, not even enter a fake line with buy/sell for the same price! You should see in your W-2, under the box 12, a "V" case declaring the total amount (all the shares x price at vesting):
http://thefinancebuff.com/restricted-stock-units-rsu-sales-and.html
http://thefinancebuff.com/rsu-sell-to-cover-deconstructed.html

Of course, keep track of the purchase price. Now it is like any other stock purchased at that price and date. You'll have to pay/get tax/loss depending on when you sell and the price at the time. Notice that according to this one can't use 83b trick for these.

Heck, I guess I need a new battery for my MKV

Oh well, my car just didn't start today. It has been acting weird for a while, with one-touch failing and some light (steering wheel, engine...) lighting up at start. Got the car started with a friends jump wires. Looked in Internet and they seem to confirm that it is the battery:
http://forums.vwvortex.com/showthread.php?5912616-MKV-GTI-Starting-Problems-Any-ideas

So, I guess this is one of those posts for me not to forget in the future the battery research I am doing...

1. OEM: Varta. Mine lasted 5 years! That was a good run. Something I need to do is to try to clean the terminals. The ground was looked pretty bad.
2. Duralast gold: 2 year warranty - Autozone $150 (says 3 years warranty) << This is what I finally got. So far no problems, and I think warranty was longer that listed here.
3. Interstate or Bosh/Exide ok
4. Absorbed Glass Mat (9AGM48)/Deka
5. Some people trash Optima while others recommend it.

Getting the rusted terminal out was really tough. Used coke and baking soda (careful where this drips, it is good to put some clothing around). Finally made enough space to fit a big screw driver between the two edges of the clam (that are closed by the screw, which I had already loosed), and twisted. That made it.

For the rest of instructions, if things are smooth, this is how it should be:
http://www.youtube.com/watch?v=Yu_en9vlZeU

Now I used like some cloth washers and a grease that comes with them (which looks like Vaseline) to protect the terminals from acid rust...

Cheers!

Eyeglass Prescription Expired

My glasses broke. Well, the frame gave up. They were those rimless/hingeless titanium kind of glasses. Funny, the salesman said they were indestructible. Well, maybe she didn't use that exact word :P and hey, they were about 5 years old. It was about time.

Anyhow, so, now what? My latest prescription was about 2 years old and it was written on it that expires after 1 year! Yeah! What the hell! But no worries. I had a history on this... When I didn't know about this rule, I went to get my sunglasses with an expired prescription and the lady, after entering the order, looked at the date and said, "that is a 7, right?" instead of the 1 on the year of the prescription. I was going to reply to her, "no, blind women, that is obviously a 1" when I realized that she was talking about the expiration date. Amazing how your brain connects the dots in fractions of a second, and I replied, "yep, a 7". LOL! :)

Well, that was then and this is now. The prescription is from 2010 and the year is 2012. A 2 looking like a 0 is going to be tough to sell, even to a blind women, ha ha! But I realized that the date was on the edge of the prescription card, so, no issue! Cut the edge out of the card and write the new one inside. Yeah, at this point, some of you must be thinking "WOW, this guy is breaking the law AND posting it on-line". Well, as you know, all this is fiction!!!  But the post is actually about that (see below). I just couldn't avoid protest about this whole thing, and this was my only way... rebellion. Plus how about the rush of doing something that can land you 30 years in jail with no parole? :P. Yeah, you always wonder about the movies where the guy hacks in the computer system of a future oppressive government, impersonates the Nazi division general, or whatever (which could have huge consequences to his life) and here I was, about to join the ranks! LOL! But hey, all what I was trying was to make easier the job of the blind salesperson...  ;). Note: for those who know me, I try to stick to the highest standards of ethics, but for the same exact reason, I will fight non-ethical rules.

So, back to the story, I take the card there, got to the shop, and shoot! The store wasn't there anymore! Tried to find where it moved, but no luck. So, now what? Should I try with the card somewhere else? Note to my biographer: This is where my criminal career started. I take the card to a famous store which we will call W. After I selected the glasses, I am ready, and yeah, show the card to the W clerk! He looks at the card, few times... Enters the prescription... And then decides to call the number on the card! AHHHHH!! And here is, like in the movies, where the handsome agent gets his help from some supernatural power... (any resemblance with reality is pure coincidence). By luck, it was already late! I had gone first to the other shop, after work, and now it was way past the closing time of the optometrist that created the prescription, so, bum. No one picks up the phone. HA HA! Still, the guy, suspicious, talks to the other clerk, comes back, and is moving really slow... At that point, I ask them how long it will take, because "I am in a rush". The guy says that maybe about 15 minutes, so, I told them that I will just come back the next day, take the card and leave before the enemy troops arrive.

So, how the whole thing finished? I later read that I could have used some online shop (see links below), but anyhow, I found a young optometrist who just open the shop and was having a promotion, so, decided to support their business and get a prescription.
 
Now to the meat of the post... Nowhere I found any "breaking the law" for the costumer. I.e., nowhere I found that trying to get glasses with an expired prescription, or one where you even fake it (this probably would require more research), would make the costumer liable of anything in front of the law. Nevertheless, there seems (from opinions, have not seen the text) to be laws requiring the person selling the glasses to make a good effort to verify the prescription is valid, or so, they say.

The most clear answer is here:
http://www.lookmatic.com/blog/2011/01/do-eyeglass-prescriptions-expire/

FAQ on the law
http://www.ftc.gov/opa/2004/10/BUS63-contactfaq.pdf

Consumer Union:
http://www.consumersunion.org/health/glassruless0200.htm

And a bit of history:
http://wiki.answers.com/Q/Why_does_your_optical_prescription_expire_after_two_years
This will help understand that it is mostly a protection of business. If you want to create a protectionist law to ensure your earnings, in healthcare is very easy... just claim to ensure quality. That is the problem with healthcare in US. The defenders of the current system claim that a free system with no government intervention is the way to go, but they do not realize this is far from a perfect marketplace! I fully agree with them, but then you should make sure competition flows everywhere. This market is completely imperfect, in economic terms. It needs the help from regulators to make sure it behaves as a free market. The same way that you have antitrust regulations.

Anyhow, just to close.... People advising about the whole BS:
http://glassyeyes.blogspot.com/2006/11/expired-eyeglasses-prescription-oh.html
There are there few comments with the exact thinking I got. I copy here a nice one that used some of the words I have used before:
"I just ran into this feeding frenzy by the vision industry. My former contacts supplier used to automatically send me more contacts every year on one prescription for three years. I always managed, all by my little self, to visit the optometrist when I felt I needed help with my vision.

I've been wearing contacts since I was 12 years old. Every time I visit an optometrist, they tell me my eyes look GREAT, very healthy. It's amazing I'm still alive after all this time without forcibly having an optometrist hold my hand (and give him cold hard cash to boot.)

I was just turned down by the contacts supplier because my optometrist said my 1 year prescription had expired. There's evidently been laws and regulations added so that suppliers can't sell them and optometrists can rake in more dough.

I have no health insurance and I am trying to start a home business. I bookmarked enough money to buy the contacts. Now I have to shell out more for the visit.

I don't think it's that Americans want to embrace socialized medicine. I think we're just reeling in the pocket book from the greed of these people who took the Hippocratic Oath.

When I last had health insurance is when I visited this optometrist. I was on a strict budget then and the whole thing, including glasses, was supposed to cost $30 because I had paid for vision insurance.

The nurse suggested this, and that, and this. I used to trust doctor's offices to give me what I really needed for my health. I now have a pair of supersonic, x-ray vision, fire-proof spectacles that would last through an atomic bomb. My bill, a surprise to me, ended up costing $177.

Two visits ago to a dentist's office, at least five employees in the office touting a 'special' gum toothpaste. They kept pushing it over and over. I did get an x-ray done between the Soupy Sales job and I definitely had to pay for that x-ray. But they missed the cavity that prompted my visit in the first place and reassured me there was nothing wrong.

After 6 months of more aggravation from this tooth, I went to another dentist and, tada, the cavity was obvious to him.

I haven't been to doctor's appointment lately where it didn't feel like I was actually at a used car lot.

We need something done with our health industry because frankly I don't think there are a lot of Americans that trust them anymore, or the pharmaceutical industry. I'm not concerned about 'being behind Europe.' I'm concerned about the shysters we have pretending to be doctors."

Cheers!

Optics/ray tracing simulation

I wanted to get a simulation where one can see the light rays in an optical system, for instance bouncing in mirrors or going through lenses. I found the following two packages:

1. A very preliminary alpha release of this: http://code.google.com/p/pyoptools/
2. One can probably use Blender with particle effect to simulate the rays. There is an example here and how to do it, here.
3. A Matlab library created by Bjorn Gustavsson: http://www.mathworks.com/matlabcentral/fileexchange/27412-opticalbench. See screenshot below. It is actually pretty easy to use and decently documented. Unfortunately doesn't cover mirrors, which I needed. I thought about adding it, as it didn't look too tough if it was a flat mirror. Nevertheless, I needed eliptical mirrors and something tells me that finding the intersection to those surfaces wouldn't be straight forward.

In the end, I decided not to complicate my life, which certainly I don't need to, for my simple problem. Will just do it mentally. Sorry if I can't help you more... If you have a good tool for this, please comment! Thank you!

UPDATE 1: My company had some licenses for Zemax, so, I endup using that. It was not very difficult to learn but I have no idea how expensive it is.

UPDATE 2: Saw the following links just to simply learn/play with optics or get a feel on lenses:

1. http://arachnoid.com/OpticalRayTracer/
2. http://phet.colorado.edu/sims/geometric-optics/geometric-optics_en.html
3. http://micro.magnet.fsu.edu/primer/lightandcolor/javalens.html

UPDATE 3: How about this one: https://ricktu288.github.io/ray-optics/ Pretty cool/easy to setup