I have mentioned previously that systematic cleaning can allow the robot to allocate more power to the vacuum motor. Neato has done exactly that. When the XV-11 turns on, it starts like a jet engine. It first starts spinning the laser head, and while the map is being prepared, the vacuum motor revs up as well. And that’s not all: when the rubber blades of the beater bar start hitting a hard floor, the Neato XV-11 becomes the loudest household robot that is used inside. Although it is not official, some sources say the noise level is 77 dB, which is even more than most of the loud lawn mower robots. The noise becomes a bit more tolerable on carpet, but Neato is not a quiet robot, that’s for sure.
The advantage of the laser rangefinder is that the robot can map the surrounding area in a few seconds without the need to turn around. (The XV-11 still makes a 180 degree turn at the start.) The rotating head allows the robot to make measurements in all directions, so the robot can have an idea of where to start the work from the very beginning. In comparison, most of the other robots will only see the boundaries of the room and the furniture in it when they bump into them or get in close proximity to them.
As with all methodically working robots, the XV-11 works in blocks. It starts each 5×5 m (16×16 ft) square by cleaning around the perimeters. (Size of blocks can vary.) Of course, if we are not cleaning a hangar, chances are that some areas will be clipped from that square, but that doesn’t bother the XV-11. It is aware of those obstacles as soon as they are visible to the laser. If the square covers part of the next room, the XV-11 will clean what is visible and reachable within the square in the first room before it moves to the next room. The door opening is automatically recognized; there is no need for active devices like lighthouses.
Randomly moving robots can adapt to changes in the environment easily since they are not aware of the changes at all. If a sofa is moved, there is a chance that the robot will go and clean the previously occupied area. If the same thing is done with a systematically moving robot after it has gone around a sofa in the original position, the original area could be completely missed. Neato’s RPS combined with the laser scanner allows the robot to recognize situations like this, letting the robot adapt to the changes and go to newly opened areas.
I found it a bit annoying that when one side of the selected block was only a half meter away from the next wall, the robot left that half meter strip to form the next block instead of extending the block to cover that area as well. Since the robot is clearly aware of the distance, it should easily adjust the block sizes to more cleverly cover the floor plan.
While measuring distances with a laser beam is cool and high tech, it is not without disadvantages. Since collision is not the main source of obstacle detection, soft barriers like curtains reaching the ground or couch skirts act as hard barriers for most of these robots (including those that use ultrasonic distance sensors). Glass and mirror can also trick the laser, confusing the robot, but I didn’t notice any strange behavior with the Neato XV-11 regarding this.
Positioning and distance measurement is very precise most of the time. When following walls or the sides of furniture it goes to within mere millimeters from them. The same applies to going around corners or table legs, but things are not entirely perfect here. I will explain this in the next section.
The cleaning ability is controversial. It doesn’t seem to have a problem with suction, and the dust bin is stuffed with dust and debris after every single run, what means it must work. On the other hand it misses quite a bit of floorspace along the edges. No matter how close it goes to the walls, without the side brushes it will never be able to pick up debris in an approximately 5 cm (2 in) wide strip along the boundaries. To make matters worse, it misses even more in the corners. Instead of pushing its square head into the corners, reaching in as much as possible, the XV-11 turns before it even reaches the corner.
Table legs pose similar problems. All currently available robots, including the Neato XV-11, turn by driving the wheels on the two sides of the robot with different speeds. This allows the robots to turn around in one spot and to go around any obstacle easily, no matter how thin it is. The XV-11 has its wheels in the middle; therefore, when it circles a table leg like this, the front of the robot, where the beater bar is, is extending outside of this circle. This means that there is always a large gap between the front of the robot and the table leg where Neato misses a circular radius of nearly 10 cm (4 in) around each table leg. Robots with side brushes easily overcome this problem by reaching out with the brushes and swiping the dust into the path of the main brush. But without such help the Neato XV-11 is crippled. It could still try to push its front closer to table legs by going around in small back-and-forth movements, aligning the front edge close to the table legs, but the XV-11 doesn’t do that. (I assume that this would take an unreasonable amount of time and power to complete in a dining room with a table and 6 chairs, so this is why it does not do this.)
Although I don’t have carpet in my house (just a few area rugs), this rubber bar cleaning technique seems to be less effective on carpet (although Neato states the exact opposite). On hard floors it works just as well as a Roomba, and despite the problems along the edges, in general I was very satisfied with the cleaning quality of Neato XV-11.
The spot mode introduced in version 2.1 is a nice addition to the features, but we stopped using it after the first few days of excitement. It is kind of annoying that the robot is unable to adapt to the environment. It draws out the same rectangle and tries to cover that area no matter what the available space is. I would expect more from a SLAM-capable robot like the XV-11.
Neato is the only company at the moment that regularly provides firmware updates to their robots. This is a great and very inexpensive way of showing commitment and care to the buyers: “You buy the gear today and we share the improvements with you in the future.”
The first upgrade came later than promised, but it brought Spot Cleaning along with several improvements and new menu languages. The second upgrade was published recently, and it improves the ability of the robot to return to the dock if accidentally knocked away while charging.
The new feature that ensures that the robot goes back to the dock when it is accidentally knocked off the dock will probably work in most cases, but it isn't a huge improvement. Previously when the connection between the robot and the dock was lost, the robot moved backwards about 1,5-2 cm (less than an inch) assuming that the dock was not far behind. With the previous firmware, if the robot was pulled more than an inch from the dock, it could not reconnect to the dock. The new firmware increases the distance the robot is willing to reverse in order to find the dock, but if the dock is a bit askew then going straight backwards won't help.
Despite the great location of the dust bin, I didn’t find it was particularly easy to empty the bin. The filter on the back of the bin serves as the removable door; therefore, the litter stuck to the filter when pulling out the debris. To avoid getting everything dusty the bin must be opened over (or almost in) a large garbage can. After emptying the bin, the filter has to be cleaned, which is another unpleasant job. I did most of that with a regular vacuum cleaner.
Other than the regular bin and filter cleaning, the robot requires almost no maintenance. Unlike the bristle bar of the Roomba robots, the rubber beater bar of the XV-11 does not collect pet and human hair. Even when it does tangle a few hair on the bar, due to the clever design, it causes no harm to the robot at all; therefore, it is enough to clean that part once a month or so.
I have seen people reporting issues with dust settling on the different sensors, including the laser head, rendering the robot unusable. During the six months I have been using this robot, I’ve never had a problem with these sensors getting blocked.
The docking process is very stable, but not entirely foolproof. Thanks to the SLAM technology the robot knows where to go when it needs to dock. It doesn’t wander around looking for the dock; it goes right there. The XV-11 will dock even if it is carried and started in another room. During the cleaning process, it will discover the position of the dock and will know where to return when it is needed. Truly amazing.
Unfortunately cleaning doesn’t always end with successful docking. Most of the problems are caused by objects laying around on the floor and getting caught by the beater bar. In general this is not the robot’s fault, although there are cases when I would expect the robot to untangle itself. The other source of the problem is unknown to me. Sometimes the XV-11 just stops somewhere and displays the “unable to navigate” message on the screen. It can even happen in front of the dock itself. If for any reason the continuity of the SLAM process breaks and the robot is unable pick it up, it will just stop and display that message. I wouldn’t say that it happens a lot, but it should not happen at all.
The robot getting stuck is not only annoying because I have to take care of it, but because the robot will beep loudly several times to let me know about the situation. If I don’t react in a few minutes, it will repeat the beeps until either I do act or the batteries are depleted. It can use up the charge of a fully charged battery in a course of a few hours, and if that happens, the robot looses track of the current time (scheduling is fine), and it has to be set once the XV-11 is on the dock again. This is extremely annoying. The robot can completely drain the battery in a single day even if it is not alerting about anything.
According to the specifications, the Neato XV-11 works for 90 minutes before it goes back to the dock for a three-hour recharging. If 90 minutes was not enough to clean the whole area, when the batteries are recharged, the robot resumes cleaning wherever it left off. This capability is probably the single most important advantage of the methodical cleaning.
Unfortunately, my XV-11 works differently. It runs for 32-33 minutes, returns to the dock, charges for about 30 minutes, then returns to clean the rest of the house (another half-hour). It is annoying because the whole area could be cleaned in 50-55 minutes if it was willing to work that long. Now it takes nearly 1.5 hours due to that half-hour recharging stop. Since I live in Europe and bought the device from the US before the XV-15 was introduced here, I should send the robot back to the US for repair, but the cost of shipping and the trouble with customs are more than what I want to pay for this. I have contacted the European Neato office to see what they can do about it, but they will help only if I buy a European warranty for €150.