Robot cleaner

Abstract

Disclosed is a cleaner comprising a cleaner body, a front wheel rotatably provided in a front portion of the cleaner body, a rear wheel rotatably provided in a rear portion of the cleaner body, a first member attached to an outer circumferential surface of the front wheel and configured to contact with a cleaning object surface, a second member attached to an outer circumferential surface of the rear wheel and configured to contact with the cleaning object surface, a front motor rotating the front wheel, a rear motor rotating the rear wheel and a controller driving the front motor and the rear motor, wherein the controller controls the front motor and the rear motor to become rotated in the opposite directions while cleaning is performed.

Claims

1. A cleaner comprising: a cleaner body; a front wheel rotatably provided in a front portion of the cleaner body; a rear wheel rotatably provided in a rear portion of the cleaner body; a first member attached to an outer circumferential surface of the front wheel and configured to contact a cleaning object surface; a second member attached to an outer circumferential surface of the rear wheel and configured to contact the cleaning object surface; a front motor rotating the front wheel; a rear motor rotating the rear wheel; a fluid tank that is configured to be positioned to vertically overlap the front wheel and not the rear wheel to concentrate a load of the fluid tank on the front wheel and to increase a friction force of the front wheel; and a controller driving the front motor and the rear motor, wherein the controller controls the front motor and the rear motor to rotate in opposite directions while cleaning is performed, wherein the cleaner body moves according to rotation of the front wheel and rotation of the rear wheel, wherein the front wheel includes a first front wheel and a second front wheel provided at respective sides of the cleaner body, wherein the front motor includes a first front motor to drive the first front wheel and a second front motor to drive the second front wheel, wherein at least one of a rotational axis of the first front wheel or a rotational axis of the second front wheel is not parallel with a rotational axis of the rear wheel, wherein the fluid tank includes: a front portion that vertically overlaps the front wheel, and a rear portion that is positioned between the front wheel and the rear wheel, wherein the front portion of the fluid tank includes a front surface having a convex shape when viewed in plan to overlap the first front wheel and the second front wheel and to be positioned behind the rotational axis of the first front wheel and the rotational axis of the second front wheel, a portion of the front surface of the fluid tank being inclined downward in front-to-rear direction to correspond to a shape of the outer circumferential surface of the front wheel, and wherein the cleaner body includes: first and second front cylinder regions provided at respective sides of the cleaner body and angled to correspond to the rotational axes of the first and second front wheels to cover the first and second front wheels, a rear cylinder region configured to cover the rear wheel, and a middle region that is narrower than the first and second front cylinder regions and the rear cylinder region in a left-to-right direction and configured to cover at least a portion of the fluid tank.

2. The cleaner of claim 1, wherein the controller drives the front motor and the rear motor and controls the rear motor to have a lower rotation speed than the front motor.

3. The cleaner of claim 1, wherein the cleaner body is moved in an opposite direction to a rotation direction of the rear motor.

4. The cleaner of claim 1, wherein the first front wheel and the second front wheel are provided at respective sides of the cleaner body to be in symmetry with respect to a center line of the cleaner body in a front to rear direction, and wherein the controller controls at least one of the first front motor or the second front motor to be rotated in an opposite direction to the rear motor.

5. The cleaner of claim 4, wherein the rear motor is rotated at a preset rotation speed which is lower than a greater one of two rotation speeds at which the first front motor and the second front motor are rotated, respectively.

6. The cleaner of claim 1, further comprising: an acceleration sensing unit sensing an acceleration of the cleaner body; a velocity sensing unit sensing a velocity of the cleaner body, wherein the controller adjusts the output of at least one of the first motor or the second motor based on information sensed by the acceleration sensing unit and the velocity sensing unit.

7. The cleaner of claim 1, further comprising: a signal receiving unit receiving a signal transmitted from an external device, wherein the controller determines a location of the cleaner body based on the signal received by the signal receiving unit.

8. The cleaner of claim 7, wherein the signal receiving unit receives, as the signal, radio waves transmitted from transmission units positioned at different locations.

9. The cleaner of claim 1, further comprising: a supply pipe guiding fluid to the front wheel from the fluid tank.

10. The cleaner of claim 9, wherein the front wheel comprises: a hollow cylindrical case having a cavity; and a plurality of outlet holes penetrating the cylindrical case, wherein the cavity is in communication with the supply pipe, and fluid is supplied to the first member via the outlet holes by centrifugal force generated when the front wheel is rotated.

11. The cleaner of claim 10, wherein the first member has a relatively large porosity and the second member has a relatively small porosity.

12. The cleaner of claim 1, wherein a liquid-content percentage of the first member is less than a liquid-content percentage of the second member.

13. The robot cleaner of claim 1, wherein the respective rotational axes of the two rotatable front wheels extend in non-parallel directions.

14. The robot cleaner of claim 1, wherein the rotational axis of the first front wheel and the rotational axis of the second front wheel are offset by an angle of 180° or more.

15. The robot cleaner of claim 1, wherein the rotational axis of the first front wheel and the rotational axis of the second front wheel are offset by an angle of 180° or less.

16. The robot cleaner of claim 1, wherein a total horizontal width of the first front wheel and the second front wheel is less than a horizontal width of the rear wheel.

17. The robot cleaner of claim 16, wherein the rear wheel passes a region through which the first front wheel and the second front wheel have passed.

18. The robot cleaner of claim 1, further comprising: a battery that is provided to vertically overlap the fluid tank.

19. The robot cleaner of claim 1, wherein the middle region of the cleaner body further includes an opening to receive the fluid tank.

20. The robot cleaner of claim 1, wherein the robot cleaner is configured to be received in a case when not in use, the case including: side and bottom walls to define a cavity to receive the robot cleaner, a front surface of the case having a curved shape corresponding to a front surface of the cleaner body, one or more support units coupled to the bottom wall of the case and configured to support the robot cleaner to be spaced from the bottom wall, and at least one blade that extends from the bottom wall to contact at least one of the first member or the second member when the cleaner is received in the case.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a perspective diagram illustrating one embodiment of the present disclosure;

(2) FIG. 2 is a diagram illustrating a low area of FIG. 1;

(3) FIG. 3 is a side sectional diagram of FIG. 1;

(4) FIG. 4 is a diagram illustrating key parts of FIG. 1;

(5) FIG. 5 is a diagram illustrating a front wheel;

(6) FIG. 6 is a conceptual diagram of diverse examples of the present disclosure;

(7) FIG. 7 is a control block diagram illustrating the embodiment of the present disclosure;

(8) FIGS. 8 and 9 are diagrams illustrating a case in which the embodiment of the present disclosure is seated stably; and

(9) FIG. 10 is a diagram illustrating another embodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

(10) Referring to the accompanying drawings, exemplary embodiments of the present disclosure according to one embodiment of the present disclosure will be described in detail.

(11) Regardless of numeral references, the same or equivalent components may be provided with the same reference numbers and description thereof will not be repeated. For the sake of brief description with reference to the drawings, the sizes and profiles of the elements illustrated in the accompanying drawings may be exaggerated or reduced and it should be understood that the embodiments presented herein are not limited by the accompanying drawings.

(12) FIG. 1 is a perspective diagram illustrating one embodiment of the present disclosure and FIG. 2 is a diagram illustrating a low area of FIG. 1. FIG. 3 is a side sectional diagram of FIG. 1 and FIG. 4 is a diagram illustrating key parts of FIG. 1. FIG. 5 is a diagram illustrating a front wheel.

(13) Referring to FIGS. 1 through 5, a robot cleaner in accordance with one embodiment of the present disclosure includes a cleaner body 10 defining an exterior design thereof; a front wheel 20 rotatably provided in a front portion of the cleaner body 10; a rear wheel 60 rotatably provided in a rear portion of the cleaner body 10; a first member 22 attached to an outer circumferential surface of the front wheel 20 to contact with a cleaning object surface; a second member 62 attached to an outer circumferential surface of the rear wheel 60 to contact with a cleaning object surface; and a water tank 80 for supplying water to the front wheel 20.

(14) The first member 22 and the second member 62 are configured to separate dust and foreign substances from the cleaning object surface (for example, the floor) while contacting with the cleaning object surface.

(15) The first member 22 and the second member 62 are rotated together with the front wheel 20 and the rear wheel 60, respectively, while contacting with the cleaning object surface. Compared with the cleaning degree of the conventional robot cleaner sweeping the floor along the movement of the cleaner body 10, the robot cleaner is able to apply a higher friction force to the cleaning object surface and have an enhanced cleaning efficiency.

(16) As shown in FIG. 1, the water tank 80 may be provided near the center of the cleaner body 10 or arranged a little bit closer to the front wheel 20 with respect to the center of the cleaner body 10.

(17) As shown in FIG. 2, the front wheel 20 includes a first front wheel 30 and a second front wheel 40 which are symmetrically arranged in both sides with respect to the center of the cleaner body 10. In other words, the front wheel 200 is configured of two wheels, not one wheel. The first front wheel 30 and the second front wheel 40 are arranged facing each other.

(18) The rear wheel 60 as one wheel may be arranged behind the front wheel 20. In case the front wheel 20 includes the first front wheel 30 and the second front wheel 40, the first member 22 is not arranged between the first front wheel 20 and the second front wheel 30 so that there can be a certain space not cleaned by the first member 22. However, the rear wheel 60 is configured as one wheel and the second member 62 contacts with all of the area where the rear wheel 60 rotatably passes, to perform cleaning for the cleaning object surface.

(19) Referring to FIG. 4, the illustrated embodiment may include a water supply pipe for guiding water to the front wheel 20 from the water tank 80 to the front wheel 20. A pump 90 is provided in the water supply pipe to generate the pressure moving the water held in the water tank 80 to the front wheel 20.

(20) The water supply pipe includes an inlet pipe 94 for guiding water from the water tank 80 to the pump 90; a transmission pipe 97 transmitting the water from the pump 90 to the branched portion to the first front wheel 30 and the second front wheel 40; and a first outlet pipe 98 and a second outlet pipe 99 branched to the first front wheel 30 and the second front wheel 40.

(21) The water flowing from the water tank 80 is guided to the pump 90 along the inlet pipe 94 and flows to the transmission pipe 97 after passing the pump 90. Hence, the water is branched to the first outlet pipe 98 and the second outlet pipe 99 from the transmission pipe 97 and then dividedly supplied to the first front wheel 30 and the second front wheel 40.

(22) The first outlet pipe 98 and the second outlet pipe 99 are symmetrically arranged with respect to the center of the cleaner body 10 so as to stop the force which might be applied to one side of the cleaner body 10 by the flux of the water flowing to the first front wheel 30 and the second front wheel 40. Accordingly, the noise or vibration generated by the flow of water may be prevented and driving stability may be then secured.

(23) The first outlet pipe 98 and the second outlet pipe 99 are provided in the portion where the first front wheel 30 faces the second front wheel 40 correspondingly, so that they can guide the water to the first front wheel 30 and the second front wheel 40, respectively. Looking down at the cleaner body 10, the front wheel 20 and the water tank 80 are overlapped with each other. As holding water, the water tank 80 is the component having a relatively more load than the other components of the robot cleaner. When the water tank 80 is overlapped with the front wheel 20, the load of the water tank 80 could be largely concentrated on the front wheel 20 and the friction force of the front wheel 20 might be increased. The friction force of the first member 22 with respect to the cleaning object surface is increased and cleaning efficiency is able to be enhanced, when the wet first member 22 in contact with the cleaning object surface performs cleaning.

(24) The front wheel 20 includes a hollow cylindrical case 31; and a plurality of outlet holes 34 penetrating the cylindrical case 31. The hollowness 33 is in communication with the water supply pipe so that water is supplied to the first member 22 via the outlet holes 34 once the front wheel 20 starts to rotate.

(25) A nozzle 36 may be further provided in the rotational axis of the cylindrical case 31 and projected inside the cylindrical case 31. The water supply pipe is configured to supply water to the nozzle 36 and a corresponding number of nozzles 36 are provided in the first front wheel 30 and the second front wheel 40, respectively. The nozzles 36 are connected to the first outlet pipe 98 and the second outlet pipe 99 to guide water to the first front wheel 30 and the second front wheel 40.

(26) The first front wheel 30 and the second front wheel 40 are formed in the same structure and located in different positions in symmetry.

(27) Meanwhile, the pump 90 is put into operation to supply water to the front wheel 20, while the front wheel 20 is rotating. When the front wheel 20 starts to rotate, a centrifugal force is generated in the front wheel 20 and the water is uniformly distributed in the front wheel 20.

(28) A gear box 24 may be provided in the opposite portion of the nozzle 36 in the first front wheel 30 and transmit the rotational force generated by the motor to the first front wheel 30. As shown in FIG. 5, the nozzle 36 is arranged in the left portion of the first front wheel 30 and the gear box 24 is arranged in the right portion of the first front wheel 30. In this instance, both the nozzle 36 and the gear box 24 are connected to the shaft of the first front wheel 30.

(29) The gear box 24 changes the rotation number or force generated in the motor and transmits the changed rotation number or force to the first front wheel 30.

(30) The outlet holes 34 provided in the cylindrical case 31 are uniformly distributed in the cylindrical case 31. When the water injected from the nozzle 36 is uniformly distributed to the cylindrical case 31, the outlet holes 34 provide the paths for supplying the water to the first member 22.

(31) The first member 22 is supplied the water having passes the outlet holes 34 and performs cleaning in contact with the cleaning object surface, with the water.

(32) The outlet holes 34 are formed in the cylindrical case 31 in plural lines and the lines are arranged at preset intervals.

(33) The first member 22 has a lower percentage of water content than the second member 62.

(34) The first member 22 is provided with water and performs cleaning for the cleaning object surface, in a state of containing water. The second member 62 is able to remove the water remaining on the cleaning object surface while moving the region where the first member 22 has just passed. In other words, the second member 62 includes the material capable of absorbing the water used by the first member from the cleaning object surface and leaving no water stains on the cleaning object surface.

(35) Specifically, the first member 22 may be made of a certain material having a relatively large porosity, for example, washing sponge and the second member 62 may be made of a certain material having a relatively small porosity, for example, microfiber. The first member 22 and the second member 62 have different porosities. Even the front wheel 20 and the rear wheel 60 are rotating at the same rotation numbers, the friction force the front wheel 20 applies can be different from the friction force the rear wheel 60 applies to the same cleaning object surface. In case the first member 22 and the second member 62 clean the same region, diverse friction forces may provide cleaning diversity and then cleaning efficiency may be enhanced.

(36) FIG. 6 is a conceptual diagram of diverse examples of the present disclosure.

(37) As one example of the present disclosure shown in FIG. 6a, the first front wheel 30 and the second front wheel 40 may be arranged to face each other, with an angle of 180 degrees between a rotation axis of the first front wheel 30 and a rotation axis of the second front wheel 40 forward.

(38) In this instance, the horizontal width (I1)) of the front wheel 20 including the first front wheel 30 and the second front wheel 40 is smaller than the horizontal width (I2) of the rear wheel 60, so that the rear wheel 60 can pass the region the front wheel has passed.

(39) As the front wheel performs cleaning, using the wet first member 22, it is quite probable that water remains on the cleaning object surface cleaned by the first member 22. The second member 62 absorbs the remaining water and finishes the cleaning.

(40) As another example of the present disclosure shown in FIG. 6b, the first front wheel 30 and the second front wheel 40 face each other, with an angle of 190 or less between the rotation axis of the first front wheel 30 and the axis of the second front wheel 40 backward.

(41) Even in this instance, the horizontal width (I1) of the front wheel 20 including the first front wheel 30 and the second front wheel 40 is smaller than the horizontal width (I2) of the rear wheel 60.

(42) When the front wheel 30 and the second front wheel 40 are inclined with respect to the front surface as shown in FIGS. 6a and 6b, the driving of the robot cleaner to change a direction of the cleaner body 10 can be facilitated.

(43) As a further example of the present disclosure shown in FIG. 6c, the rotation axis of the first front wheel 30 and the rotation axis of the second front wheel 40 are arranged on the same extended line. The horizontal width (I1) of the front wheel 20 including the first front wheel 30 and the second front wheel 40 is smaller than the horizontal width (I2) of the rear wheel 60. The rotating drive of the robot cleaner shown in FIG. 6c is performed by differentiating the rotational number of the first front wheel 30 from that of the second front wheel 40.

(44) FIG. 7 is a control block diagram illustrating the embodiment of the present disclosure.

(45) Referring to FIG. 7, the embodiment of the present disclosure includes a front motor 38 driving the first front wheel 30; a second front motor 48 driving the second front wheel 40; and a rear motor 68 driving the rear wheel 60.

(46) In other words, the two front wheels 20 and the one rear wheel 60 are driven by different motors, respectively, so that the two front wheels 20 and the one rear wheel 60 are different from each other and controlled independently.

(47) The illustrated embodiment may include a controller 200 for controlling the first front motor 38, the second front motor 48 and the rear motor 68.

(48) The illustrated embodiment may further include an acceleration sensing unit 210 sensing acceleration of the cleaner body 10 and a velocity sensing unit 220 sensing the velocity of the cleaner body 10. The controller 200 is able to control the motors by compensating the output of the motor based on the information sensed by the acceleration sensing unit 210 and the velocity sensing unit 220.

(49) The illustrated embodiment may further include a signal receiving unit 230 receiving an electromagnetic wave which is transmitted from an external device. The controller 200 may locate the cleaner body 10 based on the signal received by the signal receiving unit 230. At this time, an external beacon is capable of transmitting a radio wave which is receivable by the signal receiving unit 230.

(50) A plurality of signal oriented devices are provided in different places so that the signal receiving unit 230 can receive the radio wave transmitted from transmitters of the signal oriented devices arranged in the different places. The signal receiving unit 230 compares the strengths and directions of the received signals from the transmitters and the times when the signals are received with each other and also the information received in the former location with the information received in the current location, so that it can figure out the location or direction based on the result of comparison.

(51) The controller 200 control the front motor and the rear motor 68 to be rotated in the opposite directions while the cleaning is performed. In case the front motor includes the first front motor 38 and the second front motor 48, the controller may control one or more of the first and second front motors 38 and 48 to be rotated in the opposite direction of the direction in which the rear motor 68 is rotated.

(52) When the front motor and the rear motor are rotated in the opposite directions, for example, when the front motor is rotated in the counter-clockwise direction and the rear motor 68 in the clockwise direction, viewed in FIG. 3, the front wheel 20 is rotated in the counterclockwise direction and the rear wheel 60 is rotated in the clockwise direction.

(53) The two wheels installed in the different positions of one cleaner body 10 are rotated in the opposite directions and slip occurs in one or more wheels. Such slip occurs even when providing the force applied against the driving direction of the cleaner body 10 not in a state where the wheels stand still only to increase the friction force the robot cleaner applies to the cleaning object surface.

(54) Accordingly, the friction forces the first member 22 and the second member 62 apply to the cleaning object surface are increased and the robot cleaner is capable of cleaning the cleaning object surface, with a stronger force, only to improve the cleaning performance.

(55) The controller 200 may control the cleaner body 10 not to be moved even when the front and rear wheels 20 and 60 are rotated in the opposite directions, by adjusting the rotation numbers of the front and rear motors. In this instance, deep cleaning can be performed for the current region in contact with the first member 22 and the second member 62 of the cleaner body 10.

(56) As mentioned above, slip occurs in the wheels of the illustrated embodiment. In case of using encoder for sensing the rotation number of the motor, large errors cannot help arising in sensing the location and direction of the robot cleaner. Accordingly, the illustrated embodiment includes a transmission unit for generating a signal is provided outside the robot cleaner and the signal receiving unit receives a signal from the external transmission unit only to locate the robot cleaner based on the received signal.

(57) It is possible that the rotation number of the motor is controlled and compensated by using the encoder. The encoder cannot provide reliable information which can be used in determining the location of the robot cleaner.

(58) The front wheel 20 includes two wheels and the rear wheel 60 includes one wheel, so that the robot cleaner can be moved by the front wheel 20. In this instance, the controller 200 may drive the front motor and the rear motor 68 to make the rotation of the rear motor 68 lower than that of the front motor.

(59) If the rotation number of the front motor is higher than that of the rear motor 68, the force applied to the front wheel 20 becomes stronger enough for the front wheel 20 to move the cleaner body dominantly. The rear motor 68 performs the function of generating slip. If the rotation number of the rear motor is higher, the degree of slip becomes larger. If the rotation number of the rear motor is lower, the degree of slip becomes smaller. Accordingly, the cleaner body 10 may be moved in the opposite direction to the rotation direction of the rear motor.

(60) FIGS. 8 and 9 are diagrams illustrating a case in which the embodiment of the present disclosure is seated stably.

(61) Referring to FIGS. 8 and 9, the robot cleaner may further include a case on which the cleaner body 10 is seated. The case 100 includes a support unit 110 connected between the front wheel 20 and the rear wheel 60 to support the cleaner body 10.

(62) The case 100 is placed under the cleaner body 10 and the cleaner body 10 is rested on the case 100.

(63) The support unit 110 is arranged higher than a bottom surface of the case 100 and insertedly fitted between the front wheel 20 and the rear wheel 60 to be connected to the cleaner body 10.

(64) Wash water is held in the case 100 and the first member 22 and the second member 62 are well moistened.

(65) Moreover, a blade 106 may be provided in the case 100 to contact with the first member 22 or the second member 62. The blade 106 may be provided in both sides of the first member 22 and both sides of the second member 62, to contact with the first and second members 22 and 66 when the first member 22 and the second member 62 are rotated. When the first and second members 22 and 62 starts to rotate, the blade 106 contacts with the first and second members 22 and 62 and the foreign substances attached to the first and second members 22 and 62 are then separated.

(66) In a state where the cleaner body 10 is rested on the case 100, wash water may be held in the case 100 and the front wheel 20 and the rear wheel 60 becomes rotated with the wash water held in the case 100. Then, the wash water is absorbed to the front wheel 20 and the rear wheel 60 and friction is generated against the blade 106 so that the first member 22 and the second member 62 can be washed (a washing process).

(67) In a state where the cleaner body 10 is rested on the case 100, water with no detergent may be held in the case 100. When the front and rear wheels 20 and 60 are rotated, the water held in the case becomes absorbed to the front and rear wheels 20 and 60 and friction is generated against the blade 106 so that the first member 22 and the second member 62 can be rinsed off (a rinsing process).

(68) In addition to the washing and rinsing processes, nothing is held in the case 100 (an empty state) while the cleaner body 10 is rested on the case 100. When the front and rear wheels 20 and 60 are rotated in the empty state, the water contained in the first and second members 22 and 62 may be separated by the centrifugal force. In other words, while the cleaner body 10 is rested on the case 100, the first and second members 22 and 62 can be wrung out (a wring-drying process).

(69) FIG. 10 is a diagram illustrating another embodiment of the present disclosure.

(70) Referring to FIG. 10, the first front wheel 30 and the second front wheel 40 are arranged in an upper portion within the cleaner body 10. The water tank 80 is partially overlapped with the first and second front wheels 30 and 40.

(71) A battery 94 is provided and the electricity supplied from an external power supply source is deposited in the battery 94 and then supplied to the motor. The battery 94 may be arranged overlapped with the water tank 80.

(72) A circuit board 92 is mounted under the water tank 80 and the rear wheel 60 is arranged under the circuit board 92.

(73) The battery 94 and the water tank 80 are quite heavy in the robot cleaner, compared with the other components. Because of that, the battery 94 and the water tank 80 are arranged near the center of the cleaner body 10 in a state of getting overlapped with each other so as not to concentrate the load of the battery 94 on either of the front and rear wheels 20 and 60. Accordingly, the friction of the front and rear wheels 20 and 60 can be uniformly increased and the force applied to the first and second members 22 and 62 to contact with the floor can be uniformly increased.

(74) As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be considered broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds, are therefore intended to be embraced by the appended claims.