I needed to restrict my Vacuuming Robot today.

One fact which I had written about earlier, was that I have a “Neato XV Signature” vacuuming robot.

Neato XV _1

This robot has frequently gotten lost underneath my bed, presumably because the lower surface of my box is a canvas sheet which hangs below the sensor-line of the robot’s laser, in a way that’s curved almost parallel to the floor. The robot cannot analyze the geometry which this seems to forbid it, and can therefore sometimes end up in an endless loop. Because I want to be able to trust my robot with vacuuming 100%, when I’m not home, this error required adjustment.

Using great lengths which I have, of the magnetic boundary marker, I now also zoned off the rectangular region which is the entire underside of my bed. The robot no longer goes there.



The Drop-Sensors on my Neato XV Vacuuming Robot

I initially had the false impression, that this vacuuming robot, a “Neato XV Signature”, only had three ways to sense its surroundings: The laser which turns in its turret, the pressure-bar in the front with its two switches, and the magnetic sensors in its front corners.

Neato XV _1

But as it happens, this robot also has two optical “drop-sensors” in front, which statically look straight down at the ground.

I think the main purpose of these drop-sensors, is just to allow it to travel in a straight line. With a robot traveling over real terrain, a simple command to its left and right wheels to turn with the same amount of power, is not sufficient. This robot uses the feedback of its front drop-sensors, to measure the speed of the floor passing underneath.

I was watching it today, as it was having problems for the first time to travel in a straight line. And when I intervened, its display told me to “Please Clean My Left Drop-Sensor.”

These sensors can get dusty easily, and need to be wiped from time to time. And the plastic in front of its base-station also needs to be wiped free of dust, so that the robot can find its base-station again when ‘returning home’.

I now think that some of the malfunctions other people have reported, may in fact have been due to some of these panels not having been cleaned.

Also, it was my initial expectation that this robot stored the location of the base-station, when leaving the closest room, to clean farther reaches of its assigned area. In reality, when returning to the base station, this robot needs to find it again each time. Behind the panel of the base-station, there must be some sort of infrared corner-cubes, which glitter especially brightly in response to the laser, for it to recognize. Well it can happen that we have other objects hanging at the right or wrong distance above the ground, such as a set of curtains, which look unremarkable to the naked eye, but which also glitter to the vision of the infrared laser. And this can result in the robot making a mistaken attempt, to try docking in a corner of the correct room, but in a place where the base-station is not. And so such sources of glitter must also be removed from the room of the base-station.



A Caveat in Using Vacuuming Robots

I own a “Neato XV Signature” -brand robot vacuum cleaner. I already posted about it here:

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(Photo Added 1/21/2016 : )

Neato XV _1

I’m still very satisfied with this machine. One observation which I can make about it, is that with its robotic mind, it fails to make common-sense decisions, and for a person who’s watching it work, this can lead to some anticipatory anxiety, until it has finished. But in today’s world, AI is not supposed to duplicated Human Common Sense (yet). And so the way this robot was programmed, is such that it will still complete its full job – of maze-mapping its assigned obstacles – in spite of what Humans can plainly see as ‘stupid mistakes the robot made’. It may just take a little longer for the job to complete, but there is built-in fault-tolerance in its programming.

What’s a little less satisfying, is knowing that the dust filter on this model isn’t washable. After a certain amount of time, it will simply need to be replaced. What this means in practice, is that the companies in general, may be doing with this category of device, what many printer manufacturers already do: They may nail us on the price of future filter replacements, they way some nail us on the ink cartridges, which in some cases are also made quite small by design.

Yet, I have already bought a pack of 6 replacement filters, anticipating this situation. Those replacement filters came in the mail yesterday.



I recently acquired a Robot Vacuum Cleaner.

It can sometimes be a bit tedious for me to keep sweeping and vacuuming, and mopping. And so I felt that I must show the effort in other ways – i.e. by buying one of those vacuuming robots.

I had read that there was one model, which “moves across the floor more slowly, but which on the average vacuums a room in less time, than the others”. And so I chose that model: A “Neato XV Signature”.

(Photo Added 1/21/2016 : )

Neato XV _1

I’m very satisfied with it so far. My only real disappointment, was in the fact that this bot, which is D-shaped, only came with 6.5 feet of magnetic boundary marker. I needed to buy 3 more rolls of this magnetic strip, which were then 15 feet long each, and which can all be cut to size with a heavy pair of kitchen scissors.

I get the impression from observing it doing some of its first runs, that the logic with which it’s programmed is very good. It has a cupola, under which a laser spins with a mirror, to give it one input of obstacles. It has a front bumper with a mechanical switch on each side. And it has a magnetic sensor for the strips, in each front corner as well. The programmers seem to have made a great effort, to prevent this machine from getting into idiotic traps, as machines will do, since machines still don’t have common sense. But in spite of everything the possibility still exists that this robot can get trapped.

When it approaches a wall, by default it prefers to turn left, and then to trace this wall in that direction. It starts by tracing the perimeter of the area it’s supposed to clean counter-clockwise, and then makes rectangular sweeps at a faster pace, of the area inside this perimeter. When it’s making its faster sweeps, it has the capacity to recognize and deal with islands of barriers inside what it first saw, again by turning to the left, this time clockwise… And in dealing with obstacles it can sometimes turn right.

But the situation can still arise, that it will approach a walled-in area from the left, pass through a narrow entry-path, and then according to its sensors, when it approaches that same spot from the other side, and this time from its right, that spot may no longer look passable. And once that has happened, the machine is stuck. It will continue to run in rectangular patterns, counter-clockwise, which never repeat themselves exactly, but which also don’t lead to an exit, as when it finally reaches the point through which it came in, it turns left again, instead of turning right.

Also, one must be careful when laying the magnetic strips, so as not even to leave as much as a 1-inch gap. If it has decided to use its front-right magnetic sensor to trace along a strip, it ignores what its front-left sensor is telling it, or vice-versa. This was probably meant so that of it does slip over the magnetic boundary marker with one sensor, it won’t get caught when the other sensor crosses the same strip, as in ‘get caught with one sensor on each side of the magnetic strip’. But then the trade-off for avoiding one trap in this way, is that a 1-inch gap in the strip is enough to let it pass through all the way.

Also, it’s extremely important to me, not to allow this unit to enter my computer room – to forbid this via a magnetic strip – since it could try to march through extension cables and other cables, and possibly pull a device off the table that way, before the robot will recognize that it’s stuck. If it does get immobilized, its behavior in the past while supervised has been, to shut off all its motors, and to show a glowing red light, at the spot where the problem occurred, and to wait for help.

And so what I was doing at first, was zoning off certain regions next to my walls, with sets of two diagonal magnetic strips, that formed little triangles facing away from each wall. And I was not realizing that at the tip of these triangles, there was a slight gap each time. I replaced all those designations, with rectangular ones that leave no logical opening for the unit to slip through.

My computer room was never really in any danger, because I measured the doorway into it carefully, and fit magnetic strips into them in a straight and flush way. And by now I’m confident that the other zones I created in my living space are also secure.

As advertized, if this unit runs low in charge while cleaning a larger area, it will suspend its cleaning and return to its base unit, which must be placed along a perimeter wall and 1 meter away from any obstructions in each direction, in order to get a full charge and then go cleaning again. And I found that it was able to work for 50 minutes, after which it only needed to recharge for another 50 minutes, before it could resume.

Also, because of the high price of this toy, it’s not worth it just to let it run once per week. I have it programmed to run 3x per week now, since once it’s set up, all I’m wasting is the time of a little machine. And this way, when I get back home with dirt and snow under my boots, I find each time that the floor is magically clean. This way, it will merely assist me in my overall cleaning chores, by keeping my environment cleaner than it was before – noticeably even after three days of testing – and by reducing the amount of cleaning I need to do myself. But the day has not yet come, when a robot can do the whole chore on its own.

This unit is also rated well for its sheer cleaning power, as compared to a manual vacuum. I can see how that could be, since it seems to clean well. And it does not seem to miss any spots, thanks to its thorough programming.