EP3408471B1 - Swimming pool cleaning robot and method for using same - Google Patents

Description

The present invention relates to the field of equipment for swimming pools. It relates more particularly to a swimming pool cleaning device capable of moving along inclined walls.

Preamble and prior art

The invention relates to a device for cleaning a surface immersed in a liquid, such as a surface formed by the walls of a pool, in particular a swimming pool. These include a mobile pool cleaning robot. Such a cleaning robot performs said cleaning by traversing the bottom and the walls of the swimming pool basin, by brushing these walls, and by sucking the debris towards a filter. Debris denotes all the particles present within the basin, such as pieces of leaves, micro-algae, etc., these debris being normally deposited at the bottom of the basin or bonded to the side walls thereof.

Most commonly, the robot is supplied with energy by an electric cable connecting the robot to an outdoor control and power unit.

We know, for example, in this area, patents FR 2 925 557 and 2,925,551 , of the plaintiff, who are targeting an apparatus for submerged surface cleaning with a removable filtering device. Such devices generally include a body, members for driving said body on the immersed surface, a filtration chamber provided within the body and comprising a liquid inlet, a liquid outlet, a hydraulic circuit for circulating liquid between the 'entry and exit through a filtering device. We still know the patent FR 2 954 380 , by the same applicant, who is targeting a swimming pool cleaning robot equipped with an accelerometer making it possible to determine changes in attitude within the pool.

We also know the patent application FR 2 929 311 , of the Applicant, which relates to a rolling device for cleaning an immersed surface with a mixed hydraulic and electric drive. The rolling device rises along the surface, in particular thanks to the presence of a pumping device providing a directed hydraulic flow to bring a vertical thrust to the rolling device. A pressure sensor, allowing to know the depth of immersion from the measurement of a pressure, is present in the rolling device to detect the proximity of the water line in order to limit the rising speed of the device driving near the water line. This limitation of the rate of ascent, making it possible to prevent the device from crossing the water line and sucking in air, is carried out in reducing the power of the pumping device, and therefore the vertical thrust of the water jet.

These devices have automatic programs for cleaning the bottom of the pool and possibly the side walls of the pool. Such a program determines a cleaning of the swimming pool in a predetermined time, for example an hour and a half.

Furthermore, the maintenance of the robot in the water line, to ensure the cleaning of the latter, is usually carried out using the balance between the buoyancy and the weight of the robot when the latter is at the level of the water line. Indeed, the cleaning devices are balanced by the addition of float or ballast in order to float at the level of the water line, thus making it possible to clean the water line by following it naturally.

Generally, the robot is removed from the water by the user at the end of the cycle or at regular intervals to be cleaned, when the filter is too full of particles (leaves, microparticles etc.).

Furthermore, in the prior art, depending on the nature of the surface of the pool, the cleaning robot was able to correctly or not climb along the walls of the pool to clean them. He was known to add weights or floats to correct his behavior. It is clear that this installation was not easy, required additional means not available to the end user of the robot, and caused significant variations in the behavior of the robot in all of its developments.

In addition, during the cleaning of the basin, the filter is filled with particles generating an additional mass or even a blockage of the filter. Thus, the robot, the filter of which is blocked, may have difficulties climbing along the walls and reaching the water line. Indeed, the robot has on the one hand a greater mass linked to the filling of the filter. On the other hand, in the case of a robot comprising plating or axial thrust means linked to the pumping of water, closing the filter results in a reduction in the plating or axial thrust forces of the robot towards the surface. .

The invention therefore aims to solve some of these problems. The invention relates in particular to a swimming pool cleaning apparatus, the behavior of which along an vertical wall is improved, and allowing uniform cleaning of the swimming pool.

A main objective of the invention is to propose a swimming pool cleaning robot technique which can reach the water line of a basin in a reliable manner, in particular whatever the circumstances, and more particularly whatever the adhesion of the robot to the surface of a vertical wall of the basin and whatever the filling of the filter. Currently, the adjustment of a cleaning robot is generally carried out for a clean filter and an adhesion to the wall of the medium pool.

Another main objective of the invention is to propose a swimming pool cleaning robot technique which can carry out a uniform cleaning of the swimming pool, and more particularly a cleaning at a constant immersion depth.

Statement of the invention

The invention relates in a first aspect to a swimming pool cleaning robot according to claim 1 attached.

We call "swimming pool cleaning robot" an apparatus for cleaning an immersed surface, that is to say typically an apparatus, mobile within or at the bottom of a swimming pool, and suitable for carrying out filtration. debris deposited along a wall. Such an apparatus is commonly known under the name of swimming pool cleaning robot, when it comprises means for automated management of movements at the bottom and on the walls of the swimming pool to cover the entire surface to be cleaned.

Abuse of the term "liquid" is used here to refer to the mixture of water and debris suspended in the pool or in the fluid circulation circuit within the cleaning device.

Since the robot moves by friction on a surface, it is understood that the drive and guide means comprise means for pressing the robot onto the surface. These plating means can for example be linked to the pumping means creating a vacuum between the robot and the surface traversed by the robot. It should be emphasized that the drive, guidance and plating means can be controlled independently.

According to the invention, the control means comprise a pressure sensor making it possible to determine the immersion depth of the cleaning robot in a pool of a swimming pool, from the measurement of the ambient pressure of the robot.

Thus, the robot has a means of knowing the pressure at which it is immersed. The pressure sensor can be attached to the robot or connected by a flexible hose to the robot. In addition, the pressure sensor can be independently inside the body of the robot or outside of it.

It should be emphasized that in the case of a sensor comprising at least one electronic component, the electronic component can be protected from water by being housed inside a waterproof housing or coated with resin. It can also be a waterproof sensor integrating the electronics inside the sensor body.

• robot hors d'eau ;
• robot à la ligne d'eau ;
• robot proche de la ligne d'eau ;
• robot en immersion peu profonde ;
• robot en immersion profonde.

A robot status can be defined from the pressure read from the robot. The robot state can for example be one of the following states:

• robot out of water;
• water line robot;
• robot close to the water line;
• robot in shallow immersion;
• robot in deep immersion.

In addition, the pressure sensor allows the robot to be guided at a constant depth, for example to clean the water line in the basin.

According to the invention, the control means also comprise means for controlling the pressure measured by the pressure sensor to a set value.

The pressure control means compare the measured pressure value with a value, commonly called the setpoint, established manually or preferably automatically by the control means. The setpoint makes it possible in particular to indicate a depth of immersion to which the cleaning robot must move for a predetermined period. From the difference between the measured value and the setpoint, the servo means modify at least one of the parameters of the drive and guide means in order to guide the robot to the desired immersion depth.

The control means can for example be produced using a PID regulation system (acronym of Proportional-Integral-Derivative).

Other control means such as a regulation system P (Proportional) or PI (Proportional - Integral) can be used because the required precision and the speed of variation of the pressure are low.

In particular embodiments of the invention, the pressure sensor is an absolute pressure sensor.

In particular embodiments of the invention, the pressure sensor is a relative pressure sensor measuring the pressure difference with respect to a pressure of a sealed enclosure serving as a reference.

The sealed enclosure can be a box comprising a pressure equal to atmospheric pressure, at a bar or under vacuum. The sealed enclosure can also correspond to the engine block of the robot, the engine block corresponding to a sealed enclosure in which one of the motors of the cleaning robot is housed.

In particular embodiments of the invention, the pressure sensor is a piezoelectric sensor.

Thus, the pressure sensor delivers an electrical signal as a function of the pressure exerted on a piezoelectric material.

In particular embodiments of the invention, the pressure sensor is a piezoresistive sensor.

In particular embodiments of the invention, the pressure sensor is a strain gauge fixed to a wall subjected to ambient pressure.

In particular embodiments of the invention, the control means comprise means for recording the time spent at at least a determined immersion depth of said cleaning robot.

Thus, when the basin comprises several stages to be cleaned, the robot can be guided to a stage where the robot has spent less time cleaning.

In particular embodiments of the invention, the control means are connected to an inclinometer secured to the body of the robot.

Thus, the control means evaluate the information provided by the pressure sensor and the inclinometer, and more finely adjust the operating parameters of the drive and guide means of the cleaning robot. It should be noted that the inclinometer can be an accelerometer.

In particular embodiments of the invention, the pressure sensor is located in a median plane of the body of the robot, said plane being perpendicular to the usual axis of movement.

Thus, the pressure sensor being located in the middle of the cleaning robot between the front face and the rear face of the robot, makes it possible to detect the water line or the approach of the water line in the same way regardless of the front or rear movement of the robot.

In particular embodiments of the invention, the pressure sensor is housed, at least in part, inside the rigid waterproof case comprising a flexible membrane, the pressure sensor measuring the pressure internal to said waterproof case.

The waterproof case can be a case fixed to the body of the cleaning robot or be the waterproof block containing the robot motors. The pressure sensor measures a pressure proportional to the ambient pressure in the robot. In the case where the pressure sensor is associated with an electronic card, said electronic card can advantageously be housed inside the waterproof case. It should be emphasized that the body of the sensor can pass through a wall of said sealed housing in a sealed manner.

In particular embodiments, the pressure sensor is housed, at least in part, inside a rigid waterproof housing crossed by a capillary tube having one end inside the housing, said pressure sensor being connected sealingly at said end of the capillary tube, measuring the pressure at said end of the capillary tube, the sealed case being secured to the body of the robot.

Thus, an electronic card associated with the pressure sensor can also be placed inside the waterproof case.

In particular embodiments, the waterproof case is made of a plastic material having low thermal conduction.

Thus, the temperature inside the box is substantially constant, equal to the temperature of the water in the basin.

In particular embodiments, the waterproof case includes a Faraday cage.

Thus, the electronic components located inside the case are not subjected to the magnetic field induced by the coils of an electric motor included in the plating means and the drive and guide means of the robot.

• des moyens de pompage assurant l'écoulement du liquide dans ledit circuit hydraulique,
• des moyens d'entrainement et de guidage dudit robot de nettoyage sur une surface,
• des moyens de commande des paramètres de fonctionnement des moyens d'entrainement et de guidage dudit robot de nettoyage, les moyens de commande comprenant un capteur de pression permettant de déterminer la profondeur d'immersion du robot de nettoyage dans un bassin d'une piscine, à partir de la mesure de la pression ambiante du robot,

The invention also relates to a method for controlling a swimming pool cleaning robot, said robot comprising:

• pumping means ensuring the flow of the liquid in said hydraulic circuit,
• means for driving and guiding said cleaning robot on a area,
• means for controlling the operating parameters of the drive and guide means of said cleaning robot, the control means comprising a pressure sensor making it possible to determine the immersion depth of the cleaning robot in a pool of a swimming pool, from the measurement of the ambient pressure of the robot,

Such a method comprises a step in which the ambient pressure of the robot is compared with a so-called set pressure value and a step of controlling the operating parameters of the drive and guide means in order to reduce the difference between the ambient pressure and the set pressure.

In particular embodiments, the method comprises a step of adjusting the operating parameters of the drive and guide means as a function of the pressure detected by the pressure sensor.

In particular embodiments of the invention, the method comprises a step in which the control means guide the cleaning robot to a constant immersion depth by controlling the pressure measured by the pressure sensor to a value of instructions.

In particular embodiments of the invention, the method comprises a step in which the control means are calibrated during the first climb along a wall of the basin to be cleaned, by adjusting the operating parameters of the means drive and guidance to guide the robot to reach the water line with certainty.

In particular embodiments of the invention, the method comprises a step in which the control means determine the atmospheric pressure as the minimum pressure recorded during the first climb.

In particular embodiments of the invention, the method comprises a step in which the control means record the atmospheric pressure before the robot is immersed in the pool.

• les moyens de commande détecte l'ascension du robot de nettoyage le long d'une paroi ;
• dès lors que l'ascension est détectée, les moyens de commande ajustent les paramètres de fonctionnement des moyens d'entraînement et de guidage du robot de nettoyage, afin de permettre l'ascension le long de la paroi ;
• les moyens de commande détectent l'approche de la ligne d'eau à une distance D de la ligne d'eau, lorsque la pression relevée par le capteur de pression est égale à la somme de la pression atmosphérique et de la pression de la colonne d'eau de hauteur D ;
• dès lors que l'approche de la ligne d'eau est détectée, les moyens de commande ajustent les paramètres de fonctionnement des moyens d'entraînement et de guidage du robot de nettoyage, en diminuant progressivement la puissance des moyens d'entraînement et de guidage, afin que le robot de nettoyage atteigne la ligne d'eau avec une vitesse verticale faible, sensiblement égale à zéro.

In particular embodiments of the invention, the method comprises the following steps:

• the control means detects the rise of the cleaning robot along a wall;
• as soon as the ascent is detected, the control means adjust the operating parameters of the drive and guide means of the cleaning robot, in order to allow the ascent along the wall;
• the control means detect the approach of the water line at a distance D from the water line, when the pressure recorded by the pressure sensor is equal to the sum of the atmospheric pressure and the pressure of the column water of height D;
• as soon as the approach to the water line is detected, the control means adjust the operating parameters of the drive and guide means of the cleaning robot, gradually reducing the power of the drive and guide means , so that the cleaning robot reaches the water line with a low vertical speed, substantially equal to zero.

In particular embodiments of the invention, the method comprises a step in which the cleaning robot follows the water line while being guided by a set pressure substantially equal to atmospheric pressure.

In particular embodiments of the invention, the method comprises a step in which the control means modify the atmospheric pressure setpoint if the cleaning robot sucks in air when the robot cleans the water line.

In particular embodiments of the invention, the method comprises a step in which, after detecting that the cleaning robot has difficulty reaching the water line, or even is unable to reach it despite the adjustment of the operating parameters of the drive and guiding and / or guiding means, an indication is displayed on a user interface indicating that the filter must be cleaned.

In particular embodiments of the invention, the method comprises a step of recording the cleaning time spent by the cleaning robot in at least a given depth range.

A depth range corresponds for example to the depth values in the interval centered around a given depth value.

In particular embodiments of the invention, the method comprises a step in which the control means comprise at least one cleaning instruction in time to pass for cleaning a given depth range.

In particular embodiments of the invention, the method comprises a step in which the control means comprise at least one relative cleaning instruction comparing the times spent between at least two given depth ranges.

The invention also relates to a submerged surface cleaning device characterized in combination by all or some of the characteristics mentioned above or below.

Presentation of the figures

The characteristics and advantages of the invention will be better appreciated from the following description, which describes the characteristics of the invention through a non-limiting example of application.

• La figure 1 illustre une vue en perspective d'un robot de nettoyage de piscine mettant en œuvre un système de filtration tel qu'exposé,
• La figure 2 illustre une vue en coupe du même appareil selon un plan vertical longitudinal,
• La figure 3a illustre un procédé de pilotage du même appareil sous la forme d'un schéma synoptique,
• La figure 3b illustre une courbe d'enregistrement en fonction du temps de la pression mesurée par le capteur de pression du même appareil,
• La figure 4a illustre une vue de devant d'une variante de réalisation du même appareil,
• La figure 4b illustre une vue en perspective d'un boitier étanche logeant le capteur de pression de cette variante de réalisation du même appareil.

The description is based on the appended figures in which:

• The figure 1 illustrates a perspective view of a swimming pool cleaning robot implementing a filtration system as described,
• The figure 2 illustrates a sectional view of the same device along a longitudinal vertical plane,
• The figure 3a illustrates a process for controlling the same device in the form of a block diagram,
• The figure 3b illustrates a recording curve as a function of time of the pressure measured by the pressure sensor of the same device,
• The figure 4a illustrates a front view of an alternative embodiment of the same device,
• The figure 4b illustrates a perspective view of a sealed housing housing the pressure sensor of this alternative embodiment of the same device.

Detailed description of an embodiment of the invention

The invention finds its place within a technical swimming pool environment, for example a family type buried swimming pool.

A submerged surface cleaning device comprises, in the present nonlimiting example of embodiment, a cleaning unit, hereinafter called swimming pool cleaning robot, a supply unit and a control unit of said swimming pool cleaning robot.

The cleaning unit is shown according to an embodiment given here by way of example, in Figures 1 and 2 .

The swimming pool cleaning robot 10 comprises a body 11 and a drive and guide device comprising drive and guide members 12 of the body on an immersed surface. In the present nonlimiting example, these drive and guide members consist of wheels or tracks arranged laterally to the body (see figure 1 ).

The swimming pool cleaning robot 10 further comprises a motor driving said drive and guide members, said motor being supplied, in the present embodiment, via an on-board card.

• un axe longitudinal X_r est défini comme l'axe de déplacement du robot de nettoyage 10 lorsque les roues de déplacement 12 sont commandées à se mouvoir de façon identique,
• un axe transversal Y_r est défini comme perpendiculaire à l'axe longitudinal X_r, et situé dans un plan parallèle au plan d'appui des roues de déplacement 12 du robot de nettoyage 10, cet axe latéral Y_r étant ainsi parallèle à l'axe de rotation des roues,
• un axe vertical Z_r est défini comme perpendiculaire aux deux autres axes, le dessous du robot selon cet axe vertical Z_r étant situé entre ledit robot et la paroi parcourue, et le dessus du robot selon cet axe étant la partie du robot la plus éloignée de la surface parcourue.

We define for the remainder of the description a reference frame X _r Y _r Z _r relating to this cleaning robot 10, in which:

• a longitudinal axis X _r is defined as the axis of movement of the cleaning robot 10 when the movement wheels 12 are controlled to move identically,
• a transverse axis Y _r is defined as perpendicular to the longitudinal axis X _r , and situated in a plane parallel to the support plane of the displacement wheels 12 of the cleaning robot 10, this lateral axis Y _r thus being parallel to the wheel rotation axis,
• a vertical axis Z _r is defined as perpendicular to the other two axes, the underside of the robot along this vertical axis Z _r being located between said robot and the wall traversed, and the top of the robot along this axis being the most distant part of the robot of the area covered.

The concepts of front, rear, left, right, top, bottom, top, bottom, etc. relating to the cleaning robot are defined with respect to this reference X _r Y _r Z _r .

The drive and guide members define a guide plane on a submerged surface through their points of contact with said submerged surface. Said guide plane, parallel to the plane formed by the longitudinal and transverse axes, is generally substantially tangent to the immersed surface at the point at which the device is located. Said guide plane is for example substantially horizontal when the device moves on a submerged surface of the pool bottom.

Throughout the text, a "low" element is closer to the guide plane than a high element.

The swimming pool cleaning robot 10 comprises a hydraulic circuit comprising at least one liquid inlet 13 and a liquid outlet 14. The liquid inlet 13 is, in the present nonlimiting example, located at the base of the body 11 (in other words under it, when the pool cleaning robot 10 is placed in its normal operating position at the bottom of the pool), that is to say immediately opposite an immersed surface on which moves the swimming pool cleaning robot 10 in order to be able to vacuum the debris accumulated on said submerged surface. The liquid outlet 14 is located on the top of the swimming pool cleaning robot 10.

In the present embodiment, the liquid outlet 14 takes place in a direction substantially perpendicular to the guide plane, that is to say vertically if the swimming pool cleaning robot 10 rests on the bottom of the swimming pool, and horizontally if the cleaning device is traversing a vertical wall of the swimming pool.

The hydraulic circuit connects the liquid inlet 13 to the liquid outlet 14. The hydraulic circuit is adapted to be able to ensure the circulation of liquid from the liquid inlet 13 to the liquid outlet 14. The swimming pool cleaning robot 10 for this purpose comprises a pump comprising a motor 19 and a propeller 20 disposed in the hydraulic circuit. The motor 19 drives the propeller 20 in rotation.

This pump causes, on the one hand, a suction of water at the level of the water inlet 13 located under the cleaning robot 10, therefore as close as possible to the surface against which the cleaning robot 10 operates, and, on the other hand, a discharge of water through the water outlet 14, which is substantially perpendicular to the support plane of the cleaning robot 10 and therefore to the surface traversed. These two phenomena, suction under the robot 10 and evacuation of pressurized water above the robot 10, determine the plating forces exerted on the cleaning robot 10 towards the surface that the robot 10 is traveling. . The adhesion of the cleaning robot 10 to the wall is thereby increased, which facilitates the ascent of the cleaning robot 10.

The apparatus comprises a filtration chamber 15 interposed, on the hydraulic circuit, between the liquid inlet 13 and the liquid outlet 14.

The filtration chamber 15 ensuring the separation and storage of the debris suspended in the liquid, comprises a filtration basket 16 and a cover 17 forming the upper wall of the filtration chamber 15.

The filter basket 16 is extractable, that is to say it can be extracted from, and introduced into, the body 11 of the cleaning robot 10. The body 11 of the cleaning robot 10 has for this purpose a housing in which the filter basket 16 can be mounted. The fact that the filtration basket 16 is removable makes it easy to empty it, in particular without having to handle the entire robot 10.

The swimming pool cleaning robot 10 is, in the present example, supplied with energy by means of a waterproof flexible cable. In the present example, this flexible cable is attached to the body of the swimming pool cleaning robot 10 at its upper part. This flexible cable is connected, at its other end, to the power supply unit (not shown on the figure 1 ), arranged outside the basin, this supply unit being itself connected to the electric current on the sector.

The swimming pool cleaning robot 10 further comprises here a handle 18 adapted to allow a user to remove the robot from the water, in particular when the filter has to be cleaned.

The operating parameters of the cleaning robot 10, such as, for example, the type of cleaning cycle requested by the user, are adjusted via a user interface located on the supply unit.

It is recalled that such a cleaning robot frequently comprises two cleaning cycles. In a first cycle, the robot traverses, the bottom of the pool, and cleans it, without climbing along the side walls. In a second cycle, the robot traverses both the bottom of the pool and also rises along the side walls, so as to take off the debris that are stuck to it, or that concentrate at the level of the water line. In this second cycle, the robot climbs along the side wall, partially emerges to rub the water line with its brush, tilts to move laterally along the wall, and dives backwards by reversing its direction of travel to descend to the bottom while still cleaning the wall.

During the different cycles, the control unit (not illustrated on the figure 1 ) of the robot 10, housed in a sealed casing close to the motors, adjusts the operating parameters of the drive motor for the displacement members and of the fluid circulation pump, thus acting on the plating forces exerted on the robot towards the surface it is traveling.

In the present exemplary embodiment, the cleaning robot 10 comprises a pressure sensor 21 fixed to the body 11 of the cleaning robot 10.

In a variant of this particular embodiment of the invention, the pressure sensor is connected to the robot by a flexible hose. The flexible hose can be attached to the robot body.

The piezoresistive type pressure sensor 21 allows the robot control unit 10 to determine the depth of immersion in the basin from the measurement of the absolute pressure to which the cleaning robot 10 is subjected.

The robot control unit 10 comprises pressure control means making it possible to guide the robot 10 to a pressure corresponding to a set value, hereinafter called the set pressure. The pressure control means are in the present nonlimiting example of the invention produced using a PID regulator. The set pressure varies over time in order to guide the cleaning of the robot 10 in the swimming pool basin. The set pressure can also be constant over a period of time in order to guide the robot 10 to a given depth.

In variants of this particular embodiment of the invention, the pressure sensor can be a piezoelectric sensor, comprising for example a strain gauge. It can also be any other type of measurement sensor indicating the depth to which the cleaning robot is located, such as for example a float in a capillary tube.

The pressure sensor 21 comprises in the present example a sealed body in which the electronics of the sensor are inserted.

In a variant of this particular embodiment of the invention, the electronics of the sensor can be protected by resin or be included in a waterproof case.

It should be emphasized that the pressure sensor 21 is advantageously housed outside the hydraulic fluid circulation circuit because the pumps cause a vacuum inside the hydraulic circuit relative to the local pressure. In addition, the value of this vacuum being a function of the instantaneous power of the pumps, varies over time.

Since the mass of the robot tends to increase with the collection of debris during the cleaning of the basin, the control unit adjusts the power of the drive and / or pumping motors, in order to increase the capacity of the robot to reach the water line.

In addition, the control unit deduces the ascent or descent speed from the pressure variations detected by the pressure sensor 21. The control unit then automatically adjusts the speed of the drive members, according to the conditions d adhesion of the robot on the wall.

Furthermore, the control unit can detect via the pressure sensor 21 when the robot is close to the water line during the ascent phases along a wall of the basin.

The pressure sensor 21 is advantageously fixed in the middle of the cleaning robot 10 in the usual direction of movement of the robot 10, near one of the displacement and guide members 12. This central position of the pressure sensor 21 thus allows the control unit for detecting the water line when the pressure measured corresponds to the atmospheric pressure plus the pressure corresponding to the half-length of the cleaning robot 10. It should be emphasized that this detection of the water line is performed both in the usual or reverse direction of movement of the cleaning robot 10.

In a variant of this particular embodiment of the invention, the pressure sensor 21 is housed in the center of the front face of the robot, thus allowing the device for controlling the drive and guide means to detect the line of water when the pressure detected is significantly higher than atmospheric pressure. In variants of this embodiment of the invention, the pressure sensor 21 can be arranged at any other location of the robot, preferably but not limited to in the robot.

It should be emphasized that in order for the detection of the water line to be reliable, the control unit of the robot 10 is calibrated during the first climb along a wall of the basin to be cleaned. To this end, the control unit adjusts the operating parameters of the drive and plating motors leading the robot 10 to reach the water line with certainty. The control unit determines the atmospheric pressure as the minimum of the pressure recorded during this first climb. The control unit also confirms that the atmospheric pressure is substantially constant each time the cleaning robot reaches the water line.

In an alternative embodiment of this embodiment, the control unit records the atmospheric pressure before the robot is immersed in the pool.

The use of the pressure sensor 21 also allows the control unit to modify the parameters of the motors during the ascent of the cleaning robot 21 along a wall of a swimming pool basin.

To this end, the control unit of the cleaning robot 21 follows the piloting method 300 illustrated in figure 3a in the form of a block diagram.

During a first step 310, the control unit detects the rise of the cleaning robot along a wall. This rise results in a continuous decrease in the pressure recorded by the pressure sensor 21. It should be emphasized that the measurement of the pressure can be smoothed so as not to take account of the minute variations brought about by the noise of the sensor.

As soon as the ascent is detected, the control unit adjusts the operating parameters of the drive and plating motors of the cleaning robot 10, during step 320, in order to allow the ascent along the wall.

The control unit detects during step 330, the approach of the water line. This detection can be carried out for example at a distance of the order of fifty centimeters from the water line. This distance is detected when the pressure recorded by the pressure sensor 21 is equal to the sum of the atmospheric pressure P _atm and of the pressure P _CE of the water column from a height of fifty centimeters. In this case, P _CE is equal to fifty millibars or fifty hectoPascal.

As soon as the approach to the water line is detected, the control unit then gradually decreases the operating power of the drive and tackling motors during step 340, so that the cleaning robot 10 reaches the water line with a low vertical speed, substantially equal to zero.

The robot 10 can then follow the water line while being guided at a pressure substantially equal to atmospheric pressure. To this end, the value of the set pressure can be equal to atmospheric pressure or to a value substantially greater than atmospheric pressure in order to allow the robot 10 to follow the water line while still being submerged.

It should be noted that the use of the pressure sensor 21 also allows the control unit to modify the atmospheric pressure setpoint if the cleaning robot 10 sucks air when the robot cleans the water line.

However, if the cleaning robot 10 has an excess mass caused by the collection of numerous debris, the robot hardly reaches the water line, or even is unable to reach it despite the adjustment of the operating parameters of the motors. An indication is then displayed on the user interface indicating that the filter must be cleaned.

The set pressure allowing the robot to reach the water line is recorded.

On the other hand, the robot 10 can also advantageously be guided to a constant immersion depth by slaving the pressure measured by the pressure sensor 21 to a set value greater than atmospheric pressure. The robot 10 can thus for example clean the water line of the basin or carry out a cleaning along any depth of the basin.

The pressure control is generally carried out by first comparing the ambient pressure of the robot with the current set pressure. The operating parameters of the drive and guide means are then adjusted in order to reduce the difference between the ambient pressure and the set pressure.

In the present embodiment described here without limitation, the control unit also records the time spent at each depth. Generally recording is done for depth ranges. In the present nonlimiting example of the invention, a depth range represents a depth interval centered around a value of the set pressure.

The control unit can thus adapt the time spent by the robot to clean a particular depth, for example to clean the water line of the basin.

Curve 30 shown in figure 3b illustrates an example of recording as a function of time of the ambient pressure in the robot submerged in a basin of a swimming pool. In this example, the basin is divided into two zones: a shallow zone and a deeper zone corresponding to a plunge pool. Three pressure levels are visible on the curve 30. The highest pressure 31 corresponds to the bottom of the pit to be plunged. The pressure 32 corresponding to the intermediate bearing is linked to the bottom of the shallow area. The lowest pressure 33, substantially equal to atmospheric pressure, reflects the cleaning of the basin's water line.

The robot 10 starts here by cleaning the bottom of the plunge pool, translated by a pressure level 34 31. The robot then goes up into the shallow area and cleans the bottom of this area. The curve 30 thus has an intermediate pressure bearing 35. The robot then rises along a wall of the basin in order to clean the water line. A new bearing 36 corresponding to the lowest pressure 33 translates the cleaning of the water line. The robot then descends into the shallow area. The robot thus cleans the different areas of the pool.

At each pressure level, the control unit of the cleaning robot 10 records the time spent cleaning the bottom of each zone of the basin. When the robot enters, for example, the deepest zone, the control unit compares the time spent in this zone with that recorded in the shallow zone. If the time spent in the dive pit is greater than a previously determined threshold time, the robot 10 reverses its direction of movement and returns to the shallow area in order to continue cleaning this area. This reversal of direction of movement is illustrated on curve 30 by peak 37.

It should be noted that a threshold duration is determined in each cleaning zone. This threshold can be determined either in absolute or in relative with respect to a duration of another zone to be cleaned. These threshold times are determined in order to standardize the cleaning of the swimming pool basin. These threshold times can be a function of the surface area to be cleaned.

Recording the time spent at each depth also allows homogeneous cleaning of the stairs and beaches included in a swimming pool basin.

In variants of this particular embodiment of the invention, the pressure sensor 21 advantageously measures the pressure inside a rigid waterproof case. The Figures 4a and 4b illustrate an embodiment of one of these variants. The waterproof case 41 comprising a pressure sensor 21 is secured to a blank of the body 11 of the cleaning robot 10, as illustrated in figure 4a . The waterproof case 41, illustrated in more detail in figure 4b , is made of a rigid plastic material and comprises a flexible membrane 42. In this variant, the pressure sensor 21 is located on an electronic card 43 fixed inside the waterproof case 41. The electronic card 43 is connected to the robot control unit 10 by a cable 44 passing through the waterproof housing 41 by means of a cable gland 45. The waterproof cable 44 transmits a signal proportional to the ambient pressure at which the cleaning robot 10 evolved. The flexible membrane 42 is produced in the present example from flexible PVC. Its thickness is significantly less than one millimeter. The membrane can also be made of flexible polyurethane or coated fabric.

It should be emphasized that the housing 41 also makes it possible to thermally isolate the pressure sensor 21 from the motors and other energy dissipating components. The pressure sensor 21 thus has a substantially constant temperature, corresponding to the temperature of the water. The measurements obtained by the pressure sensor 21 are then reliable and reproducible. The waterproof case 41 also makes it possible to magnetically isolate magneto-sensitive components of the compass type, or electronic components, inserted into the case 41. For this purpose, the waterproof case 41 may comprise a Faraday cage.

In alternative embodiments of the invention, the pressure sensor is partly housed inside a rigid waterproof case secured to the body of the robot. The waterproof housing is traversed by a capillary tube, one end of which is connected in leaktight manner to the pressure sensor.

In alternative embodiments of the invention, the pressure sensor is a relative pressure sensor measuring the pressure relative to a pressure of a sealed enclosure serving as a reference. The sealed enclosure can be a box comprising a pressure equal to atmospheric pressure, at a bar or under vacuum. The sealed enclosure can also correspond to the engine block of the robot, the engine block being a sealed enclosure in which is housed the motor for driving the movement members of the cleaning robot. However, it should be noted that the temperature of the engine block changes over time. So it is necessary to correct this reference pressure in order to take into account the pressure variations linked to the temperature variations in a constant volume.

In alternative embodiments of the invention, the cleaning robot 10 also includes means for determining at any time its attitude in the swimming pool. To this end, the cleaning robot 10 comprises for example at least one inclinometer of a type known per se, or a means of detecting vertical passage of the "tilt" type or other equivalent device known to those skilled in the art. This inclinometer, which can be an accelerometer, makes it possible to determine the orientation of the cleaning robot along three axes. The control unit can then process the information coming from the means for determining the orientation of the robot 10 in the pool, by associating them with the immersion depth measured by the pressure sensor 21. Thus, the control unit can more precisely and finely adjust the operating parameters of the drive and plating motors of the cleaning robot 10.

The characteristics described above are not limiting and many other characteristics linked to the use of an ambient pressure sensor can be achieved within the scope of the invention, defined by the appended claims.

Claims (25)

1. Swimming pool cleaning robot (10) comprising:

   - a body (11),

   - at least one hydraulic liquid circulation circuit between at least one liquid inlet (13) and at least one liquid outlet (14), said hydraulic circuit comprising at least one means of separating debris in suspension in the liquid,

   - pumping means for maintaining the flow of liquid in said hydraulic circuit,

   - means of driving and guiding said robot on a surface,

   - means of controlling operating parameters of the means of driving and guiding said cleaning robot (10), the control means comprising a pressure sensor (21) for determining the immersion depth of the cleaning robot in a swimming pool, starting from the measurement of the ambient pressure around the robot,

   characterised in that the control means also comprise means of automatically controlling the pressure recorded by the pressure sensor to a set value.
2. Cleaning robot according to claim 1, characterised in that the pressure sensor is an absolute pressure sensor.
3. Cleaning robot according to claim 1, characterised in that the pressure sensor is a relative pressure sensor measuring the pressure difference relative to a pressure in a sealed chamber used as a reference.
4. Cleaning robot according to any one of claims 1 to 3, characterised in that the pressure sensor is a piezoelectric sensor.
5. Cleaning robot according to claim 4, characterised in that the pressure sensor is a piezoresistive sensor.
6. Cleaning robot according to either claim 4 or 5, characterised in that the pressure sensor is a strain gauge fixed on a wall to which ambient pressure is applied.
7. Cleaning robot according to any one of claims 1 to 6, characterised in that the control means include means of recording the time spent in at least one determined immersion depth range of said cleaning robot.
8. Cleaning robot according to any one of claims 1 to 7, characterised in that the control means are connected to at least one inclinometer fixed to the body of the robot.
9. Cleaning robot according to any one of claims 1 to 8, characterised in that the pressure sensor is located in a median plane of the robot body, said plane being perpendicular to the usual displacement axis.
10. Cleaning robot according to any one of claims 1 to 9, characterised in that the pressure sensor is at least partly housed inside a rigid sealed box containing a flexible membrane, the pressure sensor measuring the pressure inside said sealed box.
11. Cleaning robot according to any one of claims 1 to 9, characterised in that the pressure sensor is at least partly housed inside a rigid sealed box through which a capillary tube passes with one end inside the box, said pressure sensor being connected to said end of the capillary tube in a sealed manner, and measuring the pressure at said end of the capillary tube.
12. Cleaning robot according to either claim 10 or 11, characterised in that the sealed box is made from a plastic material with low thermal conductivity.
13. Cleaning robot according to any one of claims 9 to 12, characterised in that the sealed box contains a Faraday cage.
14. Method of controlling a pool cleaning robot, said robot comprising:

    - pumping means for maintaining the flow of liquid in said hydraulic circuit,

    - means of driving and guiding said robot on a surface,

    - means of controlling operating parameters for the drive and guidance means of said cleaning robot (10), the control means comprising a pressure sensor (21) that can be used to determine the immersion depth of the cleaning robot in a swimming pool, starting from the measurement of the ambient pressure around the robot.

    characterised in that the method includes a step in which the ambient pressure at the robot is compared with a value called the set pressure and a step to control the operating parameters of the drive and guidance means so as to reduce the difference between the ambient pressure and the set pressure.
15. Method according to claim 14, characterised in that it includes a step in which the control means are calibrated during the first climb along a wall of the pool to be cleaned, by adjusting the operating parameters of the drive and guidance means so as to reliably bring the robot to the water line.
16. Method according to claim 15, characterised in that it includes a step in which the control means determine the atmospheric pressure as being equal to the minimum pressure recorded during the first climb.
17. Method according to any one of claims 14 to 16, characterised in that it includes a step in which the control means record the atmospheric pressure before the robot is immersed in the pool.
18. Method according to either claim 16 or 17, characterised in that it comprises the following steps:

    - 310, the control means detect that the cleaning robot is climbing along a wall;

    - 320, as soon as climbing is detected, the control means adjust the operating parameters of the drive and guidance means of the cleaning robot, so as to allow climbing along the wall;

    - 330, the control means detect the approach to the water line at a distance D from the water line, when the pressure recorded by the pressure sensor is equal to the sum of the atmospheric pressure and the pressure of water with head D;

    - 340, as soon as the approach to the water line is detected, the control means adjust the operating parameters of the drive and guidance means of the cleaning robot, by progressively reducing the power of the drive and guidance means, so that the cleaning robot reaches the line with a low vertical velocity, approximately equal to zero.
19. Method according to claim 18, characterised in that it includes a step in which the cleaning robot follows the water line by being guided by a set pressure equal to approximately atmospheric pressure.
20. Method according to either claim 18 or 19, characterised in that it includes a step in which the control means modify the atmospheric set pressure if the cleaning robot draws in air when the robot is cleaning the water line.
21. Method according to any one of claims 18 to 20, characterised in that it includes a step in which the control means modify the set operating parameters for the drive and guidance means of the cleaning robot to reduce the approach velocity towards the water line, if the cleaning robot draws in air when the robot is cleaning the water line.
22. Method according to any one of claims 14 to 21, characterised in that it includes a step in which, after it has been detected that the cleaning robot is having difficulty in reaching the water line, or is even incapable of reaching it despite the adjustment to operating parameters of the drive and guidance means, information is displayed on a user interface to notify that the filter must be cleaned.
23. Method according to any one of claims 14 to 22, characterised in that it includes a step to record the cleaning time spent by the cleaning robot at at least one given depth range.
24. Method according to claim 23, characterised in that it includes a step in which the control means include at least one set cleaning time to be spent in cleaning a given depth range.
25. Method according to claim 23, characterised in that it includes a step in which the control means include at least one relative cleaning set value comparing times spent between at least two given depth ranges.

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