POOL-CLEANING ROBOT AND METHOD FOR DETECTING HALTING OF SUCH A ROBOT

Abstract

The invention relates to a pool-cleaning robot comprising a transport system that comprises at least one idle transport wheel train, a detritus suction system, and a system for detecting halting of said cleaning robot, the detection system comprising at least one transceiver of a light ray along an emission axis and at least one target that is secured to the transport wheel train, is aligned with said emission axis, and is suitable for reflecting said light ray so as to detect rotation of said transport wheel train.

Description

TECHNICAL FIELD

[0001] The present invention concerns the field of robotic pool cleaning. The invention, more specifically, attempts to reduce the pool-cleaning time.

[0002] Reminder: a pool has a bottom that is usually horizontal and sides that are usually vertical. During use of a pool, detritus (leaves, grass, soil, etc.) is deposited on the bottom of the pool, which makes it look bad. A cleaning robot allows detritus to be removed by moving around the entire bottom surface of the pool. From the prior art we know of an autonomous pool robot that can change its direction of movement in order to clean the entire bottom surface of the pool. Such a pool robot comprises a management module that allows transport commands to be transmitted successively. For example, the management module orders the robot to move three times from the back to the front for a duration of 30 seconds during a first movement phase, and then to turn right during a second movement phase, then move again three times from the back to the front during a third movement phase, etc.

[0003] Thus, the cleaning robot autonomously makes various movements on the bottom of the pool, without any user action. During a movement phase, the cleaning robot may get stuck against a vertical side of the pool and remain stuck for many seconds whilst waiting for a movement phase that will command the cleaning robot to move away from said vertical side.

[0004] Many systems have been proposed to detect when the cleaning robot gets stuck against a vertical side. For example, a cleaning robot may comprise a mechanical contactor adapted to come into contact with the vertical wall. When the mechanical contactor is activated, it orders a modification of the movement phase. Such a mechanical contactor presents the disadvantage of exercising a mechanical force against the vertical side of the pool which is usually covered with a coating known to a man of the art under the English term "liner". The repetitive pressing of the liner contactor may damage said coating and thus affect its lifespan. What is more, the mechanical contactor must remain watertight, which increases the complexity and the cost of such a detection system.

[0005] We know of a pool-cleaning robot from the prior art, in patent application U.S. Pat. No. 6,758,226, that aims to eliminate this disadvantage, which comprises a detection system that comprises an idler wheel adapted to be in contact with the base of the pool during the movement of the cleaning robot, a transmitter adapted to issue a beam of light and a receiver adapted to receive said beam of light. The axial runout of the detection wheel has an orifice drilled in it through which the beam of light may circulate when said orifice is aligned with the transmitter and the receiver. Thus, the receiver intermittently receives the beam of light during the rotation of the detection wheel and may deduce that the detection wheel is moving. In contrast, when the receiver does not detect any variation in light, it may deduce that the cleaning robot is stuck.

[0006] Such a detection system has many disadvantages. First of all this has a very significant size owing to the presence of an idler wheel dedicated to detection and the transmitter and the receiver which must be placed either side of the idler wheel. Owing to its size, it is hard to integrate the detection system into the cleaning robot which already comprises a motorised transport system and a detritus suction system. In practise, the idler wheel must be placed in the centre of the robot to ensure that it does not impede the movement of the cleaning robot via a "crutch effect". What is more, the idler wheel must be pushed up against the floor using an elastic spring, which also penalises its size. Finally, the cost of such a detection system is very high.

[0007] Incidentally, we also know of an infrared detection system which comprises a front infrared transmitter/receiver and a rear infrared transmitter/receiver in order to detect the vertical sides of the pool during the movement, forwards or backwards, of the cleaning robot. Such a detection system is complex to implement given that the presence of algae on the vertical sides of the pool disrupts detection. It is therefore necessary to envisage high power infrared transmitters/receivers, which are costly. For this reason, such a detection system is only mounted on large cleaning robots, used for public swimming pools, in particular.

[0008] The invention therefore aims to propose a cleaning robot that comprises a cost-effective detection system that is small in size.

SUMMARY

[0009] To this end, the invention concerns a pool-cleaning robot comprising a transport system that comprises at least one idler wheel transport train, a detritus suction system and a immobilisation detection system for said cleaning robot, the detection system comprising at least one transmitter-receiver for a beam of light along an emission axis and at least one target that is part of said transport wheel train and aligned with said emission axis, adapted to reflect said beam of light in order to detect the rotation of said transport wheel train.

[0010] By transport wheel train, we mean an integral rotating assembly comprising at least two wheels connected by at least one axle.

[0011] Thus, the transport wheel train advantageously participates in the movement of the cleaning robot. The detection system according to the invention does not require an additional wheel dedicated to detection to be added, as in the prior art, which limits the complexity, the size and the cost of such a cleaning robot. What is more, a transmitter-receiver also improves the size and reduces the constraints associated with water tightness in comparison with an assembly comprising a transmitter and a receiver. Also, since the detection is carried out over a short distance, a low power, low-cost transmitter-receiver may be used.

[0012] The transport system may be a hydraulic propulsion system, in which case all the transport wheel trains are idle mounted. Alternatively, the transport system may be motorised and comprise a motorised transport wheel train and an idler wheel train.

[0013] The detection system preferably comprises a watertight housing in which the transmitter-receiver is mounted. Said watertight housing preferably comprises a transparent side to allow light beams to travel along said emission axis. The transmitter-receiver may therefore be practically mounted inside the watertight housing by turning its emission axis towards the transparent side. The housing may then be mounted inside the cleaning robot as a standalone module. Such a detection system has a low manufacturing cost and is simple to integrate into a cleaning robot without affecting its size.

[0014] Again, the housing is preferably entirely transparent. This avoids the need to envisage a dedicated transparent side, which is costly and complex to assemble whilst maintaining water tightness.

[0015] The transmitter-receiver is preferably an infrared transmitter-receiver in order to limit its electrical consumption and cost, with the infrared transmitter-receiver preferably having a wavelength of between 800 nm and 1100 nm and this preferably being 940 nm.

[0016] The detection system is, preferably, connected to a power supply unit that has been adapted to be connected to an electrical cable. The detection system and the transport system are preferably connected to the same power supply unit.

[0017] The target preferably comprises an alternating pattern of reflective areas and non-reflective areas. Thus, the transmitter-receiver intermittently receives a beam of reflected light during rotation of the transport wheel train. Such a target is advantageous since it may be practically mounted to any part of the transport wheel train (wheel, axle, fin, etc.).

[0018] The transport wheel train preferably comprising at least two wheels linked by an axle, said target is fixed to said axle. Attaching the target to the axle rather than to the wheels provides the benefit of reducing the target size since the axle is smaller in diameter than the wheel. What is more, attaching it to the axle provides the benefit of providing more mounting space, the mounting space near a wheel being limited.

[0019] The target is, preferably, ring-shaped and attached to the edge of a longitudinal portion of the axle. The target is, preferably, positioned near to the centre of the axle, with it then being possible to reserve the lateral space of the cleaning robot for the transport system (wheels, side discharge orifices, etc.).

[0020] The cleaning robot, preferably, comprising a front wheel and rear wheel train, with each wheel train comprising an axle, said detection system is attached near to the rear axle so that it remains close to the transport system, facilitating their power supply and the sending of the command from the detection system to the transport system.

[0021] The emission axis, preferably, extends orthogonally to the axis of rotation of the wheel, preferably vertically, so as to not limit the space for the detritus suction system. What is more, such a layout allows the length of the cleaning robot to be limited.

[0022] The cleaning robot, preferably, comprises a single transmitter-receiver and a single target in order to limit its size and its complexity.

[0023] According to another embodiment, the target is attached to one of the idler wheels of the transport train. The emission axis, preferably, extends parallel to the axis of rotation of said wheel.

[0024] Said target is, preferably, attached by gluing. This advantageously allows a detection system to be practically adapted to a classic cleaning robot.

[0025] The transport system, preferably, also comprises a motorised transport wheel train. Thus the cleaning robot may move around independently. According to another aspect, the transport system has hydraulic propulsion and only comprises idler wheel transport trains.

[0026] The invention also concerns an immobilisation detection method for a pool-cleaning robot such as that presented above, with the cleaning robot moving according to a movement phase, with the method comprising the following:

[0027] a step in which said transmitter-receiver emits a beam of light along the emission axis towards said target,

[0028] an intermittent reception step in which said transmitter-receiver receives a beam of light reflected by said target, and

[0029] a step in which the movement phase for said cleaning robot is modified when said transmitter-receiver does not receive any beam of light for a set length of time or when it receives a beam of light for a set length of time.

[0030] Thus, immobilisation is detected when the beam of reflected light is no longer received intermittently. Such a method advantageously allows the cleaning of a pool to be sped up by modifying the movement of the cleaning robot when it is prevented from moving.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention shall be better understood on reading the description below, given for example only, and which refers to the attached drawings, in which:

[0032] FIG. 1 is a schematic representation in perspective of a cleaning robot according to an embodiment of the invention;

[0033] FIG. 2 is a side view of the robot from FIG. 1;

[0034] FIG. 3 is a rear view of the robot from FIG. 1, without its main body;

[0035] FIG. 4 is a close-up of the robot from FIG. 3 for which a cross-section of the detection system is shown;

[0036] FIG. 5 is a close-up of the detection system from FIG. 4;

[0037] FIGS. 6 and 7 are schematic representations of the detection system when a beam of light is or is not reflected; and

[0038] FIG. 8 is the representation of a detection signal when the cleaning robot is immobilised.

[0039] It should be noted that the figures show the invention in detail for implementation of the invention, said figures may, of course, be used to better define the invention, where applicable.

DETAILED DESCRIPTION

[0040] A pool-cleaning robot 1 as per an embodiment of the invention is presented in FIGS. 1 to 3.

[0041] The cleaning robot 1 comprises a main body 10 which extends longitudinally along an axis X oriented from the back to the front. As shown in FIG. 3, the cleaning robot 1 comprises a front wheel train 11 and a rear wheel train 12. Each train 11, 12 comprises an axle 110, 120, each of which has transport wheels 2 at its extremities. The wheels 2 are adapted to come into contact with the bottom of a pool and hold the main body 10 of the cleaning robot 1 at a set distance from said pool bottom. A cleaning robot 1, comprising two wheel trains 11, 12 is presented but it is obvious that it could have a different number of them. Likewise, it is obvious that the invention applies to a cleaning robot 1 comprising a different number of wheels 2, e.g. three.

[0042] With reference to FIG. 1, the cleaning robot 1 comprises a handle 3 on the front to allow a user to lift the cleaning robot into a vertical position.

[0043] With reference to FIG. 3, the cleaning robot 1 comprises a detritus suction system 5 in the form of a pump which is housed in main body 10. The detritus suction system 5 comprises a suction aperture vertically oriented downwards and a discharge aperture. The detritus suction system 5 also comprises a housing for collecting detritus which is positioned near the suction aperture to store the detritus collected.

[0044] The detritus suction system 5 is, preferably, connected to a power supply unit that has been adapted to be connected to an electrical cable.

[0045] In this example, with reference to FIG. 1, the cleaning robot 1 comprises a transport system with hydraulic propulsion 4 which comprises a plurality of water outlets, in particular, a front outlet 42a, a central rear outlet 42b and two side outlets 42c. Such a transport system 4 is known to a man of the art, and from patent application FR 1254892, in particular. The transport wheel trains 11, 12 are idler mounted, i.e. they do not have any mechanical drive. The wheels 2 thus essentially allow the cleaning robot 1 to be guided.

[0046] In this example, the transport system 4 comprises a mobile unit (not shown) which is mounted between the discharge aperture for the detritus suction system 5 and the water outlets 42a-c to orient the flow of water towards a predetermined water outlet 42a-c. It is obvious that the transport system 4 may comprise a different number of outlets. It is also obvious that the positioning of said outlets may be different.

[0047] The transport system 4 also comprises a management module (not shown) which defines the movement phases of the cleaning robot 1 and, to this end, controls the orientation of the mobile unit. The management module preferably comprises a circuit that has a microprocessor, and a memory which stores the sequence of the transport phases, in particular, the duration and the type of transport during a movement phase (movement from front to back, movement to the side, etc.).

[0048] According to the invention, with reference to FIG. 5, the detection system 6 comprises a transmitter-receiver 7, adapted to emit and receive a beam of light L along an emission axis, and a target 8 that is integral with transport wheel train 12 and aligned with said emission axis, adapted to reflect said beam of light L so that the rotation of said transport wheel train 12 can be detected. Thus, the detection system 6 allows the rotation of the wheels to be monitored in a practical manner, whilst keeping the size down, as shall be presented below.

[0049] The detection system 6 is connected to the management module of the transport system 4 in order to allow the movement phase defined by the management module to be modified in the event that movement prevention has been detected. As presented below, in the event that movement is prevented, the detection system 6 commands the transport system 4 to move in the opposite direction in order to release the cleaning robot 1.

[0050] In this example, with reference to FIGS. 4 and 5, the transmitter-receiver 7 comprises a watertight housing 70, preferably cylindrical in form, which houses a circuit board 71 on which an electronic component 72, adapted to emit and receive a beam of light L along an emission axis is mounted. The electronic component 72 is preferably a SMC component (Surface-Mounted Component).

[0051] The electronic component 72 is, preferably, configured to issue a beam of light L, infrared in particular, over a short distance in order to have a limited cost. The electronic component 72 is preferably configured to emit an infrared beam with a wavelength of between 800 nm and 1100 nm and this, in particular, being 940 nm. For example, an electronic component, known under the commercial name AGILENT HSDL 9100, may be sufficient.

[0052] With reference to FIGS. 6 and 7, the watertight housing 70 comprises a transparent side 73 in order to allow the beam of light L to enter said housing 60 along said emission axis. The transparent side 73 extends relative to the target 8. In this example, the watertight housing 70 is entirely transparent.

[0053] The transmitter-receiver 7 is preferably connected to an electricity supply unit, the same as that for the detritus removal system 5 and that for the transport system 4 in particular.

[0054] With reference to FIG. 3, the transmitter-receiver 7 is fixed to the main body 10 of the cleaning robot 1 and positioned near the rear axle 120 of the cleaning robot 1. Positioning to the rear is advantageous given that the front space is occupied by the detritus suction system 5 and by the handle 3.

[0055] As illustrated in FIG. 5, the transmitter-receiver 7 is positioned over the rear axle 120 so as to limit the length and provide as much space as possible for the detritus suction system 5 and the transport system 4.

[0056] The transmitter-receiver 7 advantageously presents itself in the form of a small standalone module which may be easily dismantled and replaced. What is more, its water tightness is simple to ensure, since there are no moving parts. The cleaning robot 1 preferably comprises only one transmitter-receiver 7 in order to reduce the cost of the cleaning robot 1.

Target 8

[0057] With reference to FIG. 5, a target 8 fixed to the rear axle 120 is represented in order to allow the indirect detection of the rotation of the transport wheel train 12 by monitoring the rear axle 120. Such indirect monitoring is especially advantageous as regards to size and complexity since it allows the general structure of the cleaning robot 1 to be left untouched, keeping two parallel axles 110, 120 of simple design. To this end, the emission axis of the beam of light L extends orthogonally to the axis of rotation of the wheel 2.

[0058] Detection of immobilisation of the wheels 2 of the rear axle 120 has been presented, but it is obvious that the invention also applies to the immobilisation detection of the wheels 2 of the front axle 110. Likewise, the invention also concerns detection of a target 8, directly attached to a transport wheel 2. To this end, the emission axis of the beam of light L extends parallel to the axis of rotation of the wheel 2.

[0059] The distance between the transmitter-receiver 7 and the target 8 is preferably between 3 and 100 mm, preferably between 3 and 10 mm. Thus, a low-power and low-cost transmitter-receiver 7 is sufficient.

[0060] In this example, as shown in FIGS. 5 to 7, the target 8 is ring-shaped and extends around a longitudinal portion of the rear axle 120 of the rear transport wheel train 12. The target 8 comprises an alternating pattern of reflective areas 81 and non-reflective areas 82. In this example, the reflective areas 81 are created using a reflective metal coating whereas the non-reflective areas 82 are created using a black mat coating. Alternatively, the target 8 may comprise a plurality of fins or pales, some of which are reflective and others of which are not reflective.

[0061] The reflective areas 81 and the non-reflective areas 82 are preferably of the same dimensions so that the transmitter-receiver 7 measures a regular signal when the cleaning robot 1 moves at constant speed.

[0062] An example of embodiment of the invention shall now be presented with reference to FIGS. 6 to 8.

[0063] The cleaning robot 1 is on the bottom of the pool and connected to a power supply cable (not shown) in order to allow, on the one hand, suction of detritus and, on the other hand, a transport of cleaning robot 1 based on the movement phases recorded in the management module of the transport system 4.

[0064] If there are no obstacles, the cleaning robot 1 moves at a substantially constant speed, the idler wheel transport trains 11, 12 then rotate along with their axles 110, 120 and the transport wheels 2. With reference to FIG. 2, the cleaning robot 1 moves over the horizontal side of the pool SH.

[0065] The target 8 thus rotates with the rear axle 120 and reflects the beam of light L emitted by the electronic component 72 of the transmitter-receiver 7 when a reflective area 81 is aligned with the emission axis (FIG. 6). The reflected beam of light L is received by the electronic component 72 of the transmitter-receiver 7 which generates a high T.sub.81 signal (FIG. 8).

[0066] In contrast, when a non-reflective area 82 is aligned with the emission axis (FIG. 7), the electronic component 72 of the transmitter-receiver 7 does not receive any beam of light L and generates a low T.sub.82 signal (FIG. 8).

[0067] In other words, when the cleaning robot 1 is moving, the signal generated is substantially regular. When the cleaning robot 1 is stuck, e.g. when the cleaning robot 1 is butting up against a vertical side S.sub.V, for example, a reflective area 81 or a non-reflective area 82 is aligned with the emission axis for a long period of time, thus generating a high T.sub.81 or low T.sub.82 value for a long period of time. According to the invention, we define a timeout T.sub.S after which the transmitter-receiver 7 issues a movement phase change instruction INS to the management module of the transport system 4. The timeout T.sub.S is preferably between 2 s and 10 s, preferably 5 s, in order to rapidly command a change in movement of the cleaning robot 1 on detection of an obstacle.

[0068] In this example, with reference to FIG. 8, since the non-reflective area 82 is aligned with the emission axis for a duration greater than said timeout T.sub.S, the transmitter-receiver 7 sends a movement phase change instruction INS to the management module of the transport system 4 so that the cleaning robot 1 moves away from the vertical side S.sub.V that the cleaning robot 1 was butting up against. In this example, the detection system 6 commands movement in the opposite direction in case of immobilisation.

[0069] Thanks to the invention, the cleaning robot 1 may practically detect any obstacle during cleaning (side, branch, etc.) in order to modify its movement and thus clean the pool. What is more, the detection system 6 may advantageously measure and monitor the speed of movement of the cleaning robot 1.

[0070] The invention has been presented for the cleaning robot 1 comprising a transport system with hydraulic propulsion but it also applies to a motorised transport system comprising at least one motorised transport wheel train in addition to the idler transport wheel trains.

Claims

1. Pool-cleaning robot comprising a transport system comprising at least one idler transport wheel train, a detritus suction system and an immobilisation detection system of said cleaning robot, the detection system comprising: at least one transmitter-receiver for a beam of light along an emission axis and at least one target, integral with the transport wheel train and aligned with said emission axis, adapted to reflect said beam of light in order for the rotation of said transport wheel train to be detected.

2. Cleaning robot according to claim 1, in which the detection system comprises a watertight housing in which transmitter-receiver is mounted, said watertight housing comprising a transparent side to allow the circulation of beams of light according to said emission axis.

3. Cleaning robot according to claim 1, in which the transmitter-receiver is an infrared transmitter-receiver.

4. Cleaning robot according to claim 1, in which the target comprises an alternating pattern of reflective areas and non-reflective areas.

5. Cleaning robot according to claim 1, in which, the transport wheel train comprising at least two wheels connected by an axle, said target is attached to said axle.

6. Cleaning robot according to claim 5, in which the transmitter-receiver is positioned over said axle.

7. Cleaning robot, according to claim 1, in which said target is attached by gluing.

8. Cleaning robot according to claim 1, in which the transport system further comprises a motorised transport wheel train.

9. Cleaning robot according to claim 1, in which the transport system comprises several idler wheel transport trains.

10. Immobilisation detection method for a pool-cleaning robot according to claim 1, the cleaning robot moving in accordance with a movement phase, the method comprising: a step in which said transmitter-receiver emits a beam of light along the emission axis towards said target, an intermittent reception step in which said transmitter-receiver receives a beam of light reflected by said target, a step in which the movement phase for said cleaning robot is modified when said transmitter-receiver does not receive any beam of light for a set length of time or it receives a beam of light for a set length of time.