EP3512398A1 - Floor cleaning robot - Google Patents

Abstract

The invention relates to a floor cleaning robot comprising: a chassis (20), a bumper (10) which can move relative to the chassis (20), and means for detecting the movement of the bumper (10) relative to the chassis (20). The cleaning robot is characterised in that it comprises means for guiding the bumper (10), arranged to move the bumper (10) in a particular way relative to the chassis (20), the components of said movement being contained in a base plane.

Description

 ROBOT OF N ETTOYAG E SOIL

The present invention generally relates to a floor cleaning robot, and in particular an autonomous floor cleaning robot provided with means for recovering and / or suctioning the waste.

It is known in the prior art autonomous soil cleaning devices, and in particular those that automatically detect the obstacles to then bypass them. For example, the document US2004143930A1 describes a cleaning robot comprising an articulated bumper that can pivot about an axis to trigger sensors during contact with an obstacle. However, if the contact is made at the height of the pivot axis, it is not certain that the bumper can pivot, because the pivoting torque is zero (especially when the contact force passes through the pivot axis, the lever arm is zero, and thus the pivoting torque is also zero). This results in a non-detection of the obstacle and a blocking of the cleaning robot against this obstacle. An object of the present invention is to meet the disadvantages of the documents of the prior art mentioned above and in particular, first of all, to propose a cleaning robot with a simple bumper, but which allows the detection of any obstacle, whatever the position of the point of contact between the bumper and an obstacle. For this, a first aspect of the invention relates to a floor cleaning robot, comprising:

 - a chassis,

 a mobile bumper with respect to the chassis,

 means for detecting a movement of the bumper with respect to the chassis,

characterized in that the cleaning robot comprises guiding means bumpers arranged to impose a movement of the bumper relative to the chassis, wherein the components of said movement are contained in a base plane. In other words, the movement of the bumper relative to the chassis is a plane movement: the bumper can move only parallel to the base plane (parallel to the floor to be cleaned). Consequently, a contact on the bumper will necessarily cause a displacement of the latter, regardless of the point of contact and in particular regardless of the altitude of the point of contact. This results in better detection of obstacles and the possibility of providing a bumper that is the height of the cleaning robot, while being able to effectively detect obstacles.

We will neglect of course the construction sets that will necessarily allow some movements in a normal direction to the base plane, but we can consider that these parasitic movements have a much lower travel to a maximum travel in the base plane, and for example can provide a set of 0.4 mm to 0.6 mm normal to the base plane, for a movement in the base plane of about 5 mm for example.

Advantageously, the guide means comprise at least three support points between the frame and the bumper, not aligned and each blocking at least one translation of the bumper in the same direction normal to the base plane. The three points of support are, for example, plane supports, and in particular block the degree of freedom which is a normal translation to the basic plane.

Advantageously, the basic plane is parallel to the floor to be cleaned. Advantageously, the guiding means comprise at least three pairs of support points between the frame and the bumper, not aligned, each pair of support points comprising two opposite support points each blocking at least one translation of the barrier. shocks in the same direction normal to the basic plane. This implementation makes it possible to block any displacement of the bumper according to the vertical (the basic plane being horizontal) in the simplest way possible, and respecting the isostatism.

Advantageously, the guiding means comprise:

at least one plane portion parallel to the base plane,

at least three pairs of holding elements, each pair of holding elements sandwiching said at least one flat portion to impose the movement of the bumper in the base plane. The holding elements are advantageously washers, which amounts to positioning the washers on both sides of the flat portion. The holding elements then form the fulcrums.

Said at least one flat portion is integral with, and / or formed on, one of the frame and the bumper, and the holding elements are integral with, and / or formed on, the other of the frame and the bumper -chocs.

Advantageously, the cleaning robot comprises at least three elongate supports each arranged to support a pair of holding elements, and said at least one flat portion comprises at least three openings each arranged to pass a support and / or at least one element. holding member supported by said support through said at least one flat portion. Said at least one flat portion is secured to and / or formed on one of the frame and the bumper, and said at least three elongate supports are integral with and / or formed on the other of the frame and the bumper .

Advantageously, the cleaning robot comprises stop means, arranged to limit a relative displacement of the bumper relative to the frame, in a displacement zone which has a shape of a circular segment.

Advantageously, the stop means comprise said at least three openings and said at least three supports. This implementation allows to define the displacement zone directly with the openings passing the support on either side of the flat portion.

Advantageously, said at least three openings have a circular segment shape formed by a circle cut by a rope normal to a direction of advancement of the cleaning robot.

Advantageously, the cleaning robot comprises elastic means arranged to return the bumper to a rest position, occupied by the bumper when there is no obstacle touching the bumper.

Advantageously, the cleaning robot comprises a plurality of pairs of centerings each comprising:

 a frame centering secured to the chassis and

 an integrated centering integral with the bumper,

 and the resilient means comprises a plurality of springs each having one end engaged with a centering center of a pair of centerings, and another end engaged with the onboard centering of said pair of centerings.

Advantageously, at least one centering center of a pair of centerings has a projection in the base plane offset from a projection in the base plane of the corresponding chassis centering, when the bumper is in the rest position. Such an offset imposes a constraint of springs, so that the rest position is more stable than if none of the springs is prestressed. Particularly advantageously, the springs are two by two prestressed in opposite directions. In other words, their centering pairs are symmetrically or oppositely shifted.

Advantageously, the projection in the base plane of said at least one onboard centering of a pair of centering is offset by at least 1.5 mm from the projection in the base plane of the corresponding chassis centering. Such an offset value makes it possible to prestress (in flexion) the springs to ensure a stable bumper rest position and an effective return to the rest position.

Advantageously, the centerings are pawns. It is then easy to put the ends of the springs on such protruding pins. It can be provided a force mounting of the springs on the pins. It is also possible to provide the springs in tension (in tension or in compression) even in rest position of the bumper, to limit vibrations and noise.

Advantageously, the detection means comprise at least:

a first sensor arranged to detect a movement of the bumper in a transverse direction of the cleaning robot,

 a second sensor arranged to detect a movement of the bumper in a transverse direction of the cleaning robot opposite to the direction detected by the first sensor,

 a third sensor arranged to detect a movement in a direction of advancement of the cleaning robot.

Such sensors make it possible to differentiate the direction of contact on the bumper, so as to improve the subsequent bypass by the cleaning robot. By transverse direction is meant a direction normal to the advancement direction of the cleaning robot, the advancement direction being obtained when all its driving wheels (of the same diameter) rotate at the same speed.

Advantageously, the detection means comprise a fourth sensor arranged to detect a movement in a direction of advance of the cleaning robot, and the third sensor and the fourth sensor are arranged on either side of a median longitudinal plane of the robot. of cleaning. Such an arrangement makes it possible to deduce the position of impact with an obstacle according to the activated sensors.

Advantageously, the sensors are switches. Such switches have a direction of depression, and therefore an impact with an obstacle will activate them selectively, so that it is possible to deduce the direction of impact and thus the position of the obstacle by analyzing the switches activated or not.

Other features and advantages of the present invention will appear more clearly on reading the following detailed description of an embodiment of the invention given by way of non-limiting example and illustrated by the appended drawings, in which:

- Figure 1 shows a perspective view of a cleaning robot according to the invention, equipped with a movable bumper;

- Figure 2 shows a perspective view of the bumper of Figure 1, and in particular a side of the bumper next to the body of the cleaning robot;

FIG. 3 represents a view from above of the bumper of FIG.

1;

 - Figures 4a and 4b show a detail of elastic means arranged to bring the bumper of Figure 1 in a rest position;

FIG. 5 represents a detail of the bumper of FIG. 1;

- Figures 6 and 7 show a detail guide means of the bumper of Figure 1;

FIG. 8 shows the possibilities of detecting the movement of the bumper of FIG. 1, as a function of obstacles encountered by the cleaning robot of FIG. 1.

Figure 1 shows a cleaning robot equipped with a bumper 10 movable relative to a frame 20 of the cleaning robot. The cleaning robot is a robot designed to autonomously clean the floors of a house, and for this purpose comprises drive wheels 22, a suction slot 27 equipped with a rotating brush. The cleaning robot embeds on its frame 20 an outer casing 21, as well as the bumper 10. Of course, there are means of storing electrical energy, such as a battery, means of control of the drive wheels and a waste storage bin, to be able to operate autonomously.

The bumper 10 is movable relative to the frame 20, to be able to detect the presence of any obstacles to the path of the cleaning robot. In particular, there are provided detection means arranged to detect a displacement of the bumper 10 caused by the encounter with an obstacle, in order to be able to modify the trajectory of the cleaning robot, as will be explained in FIG. 8, which shows the detection means formed by sensors, such as switches 41A-41D. Figure 2 shows a perspective view of the bumper 10, and in particular the side facing the cleaning robot. The latter comprises guide means 30 arranged to impose a particular movement of the bumper 10 relative to the rest of the cleaning robot, and in particular with respect to the frame 20. In fact, the guide means 30 comprise three pairs of holding elements each formed by two washers 24 (also visible in Figures 6 and 7) mounted on an elongate support 23 which is integral with a frame member 20a, connected to the frame 20. It is possible to provide the washers 24 and the bumper 10 made of plastic, and in particular polyoxymethylene (or polyformaldehyde or polyacetal), acronym POM.

The bumper 10 comprises two flat portions 1 1 a and 1 1 b, ribs or flat walls for example, and the two washers 24 of each pair of holding elements sandwich one of the flat portions 1 1 a or 1 1b (as shown in detail in FIGS. 5 and 6). In other words, each washer 24, with its respective flat portion 1 1 a or 1 1 b, forms or imposes a plane support on the bumper 10 in a direction normal to the planar portions 1 1 a and 1 1 b, for to impose a displacement parallel to or contained in a base plane, parallel to the planar portions 1 1 a and 1 1 b. As each pair of holding element comprises two washers 24 sandwiching the bumper 10, it can move only in the base plane. For each pair of holding member, a washer is threaded on the elongate support 23, and another the cap and is fixed by screw, clipping or even gluing or pasting. As shown in Figures 2, 3 and 8, it is expected to equip the cleaning robot with at least 3 pairs of holding elements, which are not aligned, to provide effective guidance and is close to an isostatic system .

However, it is obvious that a clearance between the bumper 10 and the guide means is provided, that is to say that the flat portions 1 1 a and 1 1 b of the bumper 10 can play in the pairs of holding element. As a result, the bumper may have parasitic movements in a direction perpendicular to the base plane. However, these movements are limited. In particular, the clearance can be 0.5 mm, and the total deflection of the bumper in the base plane can be 4.5 mm along each direction of a Cartesian coordinate system. In other words, the maximum possible movement of the bumper in the direction normal to the base plane is less than 15% of a maximum displacement value of the bumper in the base plane.

As a result, the movement of the bumper 10 is essentially plane, which makes the displacement of the bumper 10 independent of the height at which a possible obstacle touches the bumper. Indeed, an obstacle is flush with the ground or height, it will impose a movement of the bumper 10 substantially plane, which makes the detection of obstacles more effective than if the bumper was articulated around an axis rotation for example.

As seen in FIG. 3 and especially FIG. 5, the planar portions 11a and 11b have openings 13 in the form of circular neighborhoods, through which the elongated supports 23 pass. These lights 13 limit the movement of the bumper 10 forming abutment means which can for example limit the displacement of the bumper to 4.5 mm along the horizontal direction of Figure 3 and the same value along the vertical direction of Figure 3. The bumper 10 being movable relative to the frame 20, it is important to be able to ensure a nominal position or rest of the bumper 10 when no obstacle affects it. For this purpose, the cleaning robot comprises elastic means arranged to return the bumper 10 in a rest position, as shown in FIG 3 or 5. These resilient means comprise springs 25 visible Figure 2 and especially Figure 4a.

The springs 25 are fixed between the frame member 20a and the bumper 10, possibly with a preload to press the bumper 10 on the washers 24 upper or lower, so as to avoid rattling noises. Any movement of the bumper will stretch the springs 25, which will then exert a force on the bumper to bring it back to the rest position at the end of the contact between the bumper and the obstacle.

Figures 4a and 4b show the mounting of the springs 25 between the frame member 20a and the bumper 10. Each spring 25 is mounted on a chassis centering 26 (integral with the frame 20) and an onboard centering 12 (integral with the bumper 10). In FIG. 4b, the chassis centerings 26 and the onboard centering 12 are aligned and aligned (when the bumper 10 is in the rest position). It can be provided to shift them to impose a bending of the springs 25 in the rest position (it is necessary to shift the centering of two springs 25 in an opposite manner to compensate for the bending forces), so that this bending or prestressing can accentuate the return efficiency of the springs 25 on the bumper 10 during small displacements.

FIG. 8 represents the detection possibilities offered by the mobile bumper according to the invention. Indeed, if there are four detection sensors formed by switches 41A to 41D placed schematically as in Figure 8, and the bumper 10 is subjected to contacts with obstacles rated 1 to 7, then the switches 41 A to 41 D will be activated as shown in the table below. Switch Switch Switch Switch

41A 41 B 41 C 41 D

Obstacle 1 1 0 0 0

Obstacle 2 1 1 0 0

Obstacle 3 0 1 0 0

Obstacle 4 0 1 1 0

Obstacle 5 0 0 1 0

Obstacle 6 0 0 1 1

Obstacle 7 0 0 0 1

(0: switch not activated

1: switch on)

It is understood that it is possible to determine with the four sensors the position of the obstacle, so that the path change strategy of the cleaning robot is effective. It can be provided to space the switches 41 B and 41 C of about 100mm for example.

It will be understood that various modifications and / or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims. In particular, reference is made to coil springs, but spring blades, flexible rods, or any other type of resilient element may be provided.

Claims

REVE ND ICATIONS 1. Floor cleaning robot, comprising:  a chassis (20), a bumper (10) movable relative to the chassis (20),  means for detecting a movement of the bumper (10) relative to the chassis (20),  the cleaning robot comprising guide means (30) for the bumper (10) arranged to impose a movement of the bumper (10) with respect to the frame (20), in which the components of said movement are contained in a basic plan, characterized in that the guide means (30) comprise at least three bearing points between the frame (20) and the bumper (10), non-aligned and each blocking at least one translation of the bumper (10) in the same direction normal to the base plane. 2. cleaning robot according to the preceding claim, wherein the guide means (30) comprise at least three pairs of support points between the frame (20) and the bumper (10), non-aligned, each pair of bearing points comprising two opposite bearing points each blocking at least one translation of the bumper (10) in the same direction normal to the base plane. Cleaning robot according to one of the preceding claims, wherein the guiding means (30) comprise:  at least one plane portion (1 1 a, 1 1 b) parallel to the base plane, at least three pairs of holding elements, each pair of holding elements sandwiching said at least one flat portion (1 1 a, 1 1 b) to impose the movement of the bumper (10) in the plane basic. 4. Cleaning robot according to the preceding claim, comprising at least three elongated supports (23) each arranged for supporting a pair of holding members, and wherein said at least one planar portion (11a, 11b) comprises at least three openings (13) each arranged to pass a support and / or at least one holding supported by said support through said at least one flat portion (1 1 a, 1 1 b). 5. cleaning robot according to one of the preceding claims, comprising stop means, arranged to limit a relative displacement of the bumper (10) relative to the frame (20), in a displacement zone which has a shape of a circular segment. 6. cleaning robot according to the preceding claim in its dependence on claim 4, wherein the abutment means comprise said at least three openings (13) and said at least three supports. 7. Cleaning robot according to the preceding claim, wherein said at least three openings (13) have a circular segment shape formed by a circle cut by a rope normal to a direction of advance of the cleaning robot. 8. Cleaning robot according to one of the preceding claims, comprising elastic means arranged to return the bumper (10) in a rest position, occupied by the bumper (10) when no obstacle does not touch the bumper shocks (10). Cleaning robot according to the preceding claim, comprising a plurality of pairs of centerings each comprising:  a chassis centering (26) integral with the frame (20) and  an onboard centering (12) integral with the bumper (10), and wherein the resilient means comprises a plurality of springs (25) each having one end engaged with a centering center (26) of a centering pair, and another end engaged with the onboard centering (12) of said pair of centers. centering. 10. Cleaning robot according to the preceding claim, wherein at least one onboard centering (12) of a pair of centerings has a projection in the base plane offset from a projection in the base plane of the chassis centering (26). ) corresponding, when the bumper (10) is in the rest position. 1 1. Cleaning robot according to the preceding claim, wherein the projection in the base plane of said at least one onboard centering (12) of a pair of centering is shifted by at least 1.5 mm from the projection in the base plane the corresponding chassis centering (26). Cleaning robot according to one of the preceding claims, wherein the detection means comprise at least:  a first sensor arranged to detect a movement of the bumper (10) in a transverse direction of the cleaning robot,  a second sensor arranged to detect a movement of the bumper (10) in a transverse direction of the cleaning robot opposite to the direction detected by the first sensor,  a third sensor arranged to detect a movement in a direction of advancement of the cleaning robot. 13. Cleaning robot according to the preceding claim, wherein the detection means comprises a fourth sensor arranged to detect a movement in a direction of advance of the cleaning robot, and wherein the third sensor and the fourth sensor are arranged from and another of a median longitudinal plane of the cleaning robot. 14. Cleaning robot according to one of claims 12 or 13, wherein the sensors are switches (41 A, 41 B, 41 C, 41 D).