The principle of the suction robot is simple: it travels through the room and sucks up dust and dirt. When it is finished, it drives back to its charging station, docks there and recharges itself. However, a distinction is made between two systems of how the suction robot cleans individual rooms. These differ considerably and are decisive for the significant price differences.
A strategy is called a chaos system or amoeba strategy. For the observer, this strategy of cleansing seems rather chaotic and aimless, hence the name. The suction robot actually drives straight ahead without a plan until it encounters an obstacle. It determines this by means of an infrared sensor and then calculates by means of a distance sensor in which direction it should proceed. How large the angle of rotation of the robot is when it turns away due to an obstacle is determined by a kind of random generator. In addition, there is a so-called random strategy. If the suction robot does not encounter an obstacle for a longer period of time, it acts as if this were the case. The angle at which the robot bends is also seemingly random again.
Even if the work of the suction robot from the outside appears to be completely unplanned, it is still subject to a mathematical system. The advantage of suction robots that work according to the chaos system is that they require less complex software. This makes production simple and the suction robot cheaper to purchase for the end customer. In addition, the chaos system actually works and the suction robot sucks the entire floor. However, this is only possible if the robot has enough time to do so. Another advantage is that a robot with a chaos system is highly likely to clean a spot more than once and thus reliably pick up dirt. The disadvantage of these vacuum cleaning robots is that they can be used in very winding flats and rooms with many obstacles. Since the robot very often detects an obstacle via the motion sensor, it has to change the direction of travel again and again. Under certain circumstances, this can lead to the suction robot getting stuck or certain areas simply not being cleaned.
As a rule, suction robots with a chaos system have a timer with which you can specify how long the robot should clean the room. Depending on the size of the room, it is otherwise quite possible for the suction robot to spend one to two hours cleaning or until its battery is completely empty.
The second strategy is the so-called system navigation. Here, the suction robot systematically cleans the room in tracks and does not travel unstructured through the room until it encounters an obstacle. The robot first measures the room via the ceiling height and determines possible obstacles. It then calculates how it can clean the room most quickly and easily without taking detours or cleaning certain sections twice.
Robots in the higher price segment even develop room plans and determine the size of furniture by driving around it. As a rule, the various models then save the plan of the apartment and apply it directly during the next cleaning process. Robots that work with system navigation have cleaned the room much faster than robots with a chaos system. Depending on the size of the room, the robot may not even need 30 minutes to clean. Another advantage is that the suction robot docks less frequently on furniture, as it has already included it in its calculations and bypasses it accordingly.
Otherwise, the various suction robots still have individual cleaning strategies such as the so-called spiral drive or strategic wall tracking. Robots with system navigation often use wall tracking to precisely measure the room. Modern suction robots often use spiral tracking when they detect a very dirty spot via the sensors.
Which robot you choose is ultimately also a question of cost. Many practical tests have shown that suction robots that vacuum the room using system navigation work more thoroughly. However, these suction robots are in the higher price segment, but work faster and do not leave out any jobs. The long-term wear of both models must also be taken into account. The considerably longer cleaning time for a robot with a chaos system promotes faster wear of the suction robot.
Not to be neglected, by the way, is the suction power. A robot that travels through the entire room but hardly picks up any dirt is not necessarily preferable to a robot with a chaos system. Therefore, when purchasing a robot, you should not only pay attention to the strategy of the suction robot but also to the suction power. The techniques described are based on an ideal case; it is quite possible that not every suction robot cleans every apartment well in the same way. Some things must also be taken into account in practice: For example, there are models that require light for the cleaning drive. Otherwise, the sensor cannot work properly.