Patent Description:
In general, a cleaner includes a cleaner body, which is provided with a suction unit and a dust container, and a cleaning nozzle, which is connected to the cleaner body and performs cleaning while contacting an area to be cleaned.

The cleaner is classified into a manual cleaner, with which a user manually performs cleaning of an area to be cleaned, and an automatic cleaner that performs cleaning while traveling autonomously on an area to be cleaned.

In the case of a manual cleaner, suction force is generated in a suction unit by the power of an electric motor. In this state, if a user grips a cleaning nozzle or a cleaner body with the hand and puts the cleaning nozzle on an area to be cleaned, foreign substances such as dust present on the area to be cleaned are sucked into the cleaning nozzle by the suction force, and the sucked foreign substances are collected in a dust container. In this way, the cleaning operation of the manual cleaner is performed.

In the case of an automatic cleaner, in addition to the suction unit and the dust container, an ultrasonic sensor and/or a camera sensor is mounted to a cleaner body. While the cleaner body travels autonomously on an area to be cleaned using the aforementioned sensor, foreign substances present on the area to be cleaned are sucked into the cleaning nozzle by the suction force generated in the suction unit, and the sucked foreign substances are collected in the dust container. In this way, the cleaning operation of the automatic cleaner is performed.

The cleaning nozzle of the manual cleaner is moved and brought into close contact with an area to be cleaned by a user, whereas the cleaning nozzle of the automatic cleaner is coupled to the cleaner body so as to be brought into close contact with an area to be cleaned.

Each of the manual cleaner and the automatic cleaner further includes wheels, which are mounted to the cleaner body and by which the cleaner body can move. Wheels mounted to the manual cleaner enable a user to easily pull the cleaner body placed on an area to be cleaned while performing cleaning. Wheels mounted to the automatic cleaner are rotated by the drive force generated in an electric motor, whereby the cleaner body can travel autonomously.

Recently, cleaners capable of selectively performing automatic cleaning or manual cleaning have been actively developed. Regardless of whether a cleaner is configured to perform only automatic cleaning or is capable of selectively performing automatic cleaning or manual cleaning, when the cleaner is operated in an automatic cleaning mode, the cleaning nozzle is maintained in close contact with an area to be cleaned while the cleaner body is traveling. However, the state of the area to be cleaned, on which the cleaner travels, can vary greatly, which has a great influence on the traveling performance of the cleaner.

For example, in the case in which the floor of a living room is covered with a carpet, fibers of the carpet may be drawn into a suction port by the suction force of the cleaning nozzle, and this suction force applied between the carpet and the suction port may prevent the cleaner from traveling smoothly. In addition, when the cleaner is operated in an automatic cleaning mode and is traveling on a carpet, the wheels may slip due to the fibers of the carpet, whereby the cleaner may not travel normally. Furthermore, the cleaning nozzle may be stuck in the carpet, and thus a large amount of friction may be generated between the cleaning nozzle and the carpet, whereby the cleaner may not travel normally.

The cleaner is further equipped with a battery for storing electrical energy. In the case of a recently developed cleaner, when the state of charge of the battery drops below a predetermined level during an automatic cleaning mode, the cleaner travels autonomously to a charging stand and is automatically docked with the charging stand so that the battery is charged.

In particular, in the case of a cleaner capable of selectively performing automatic cleaning or manual cleaning, the charging stand charges the battery using a high voltage of 72V. Therefore, for safety reasons, the charging stand is configured such that the charging terminals thereof are not exposed at normal times and are exposed only when the cleaner is docked therewith. For this reason, it is very important for a cleaner, which is configured to selectively perform automatic cleaning and manual cleaning, to be docked with the charging stand automatically and securely.

In order to adjust the suction force of the cleaning nozzle with respect to an area to be cleaned and to allow the cleaner body to be automatically docked with the charging stand, which charges the battery using a high voltage of 72V, the cleaner body must be configured to ascend or descend.

A conventional cleaner is configured such that a wheel unit including wheels ascends or descends and consequently a cleaner body, to which the wheel unit is mounted, ascends or descends. In other words, if the wheel unit ascends or descends in the state in which the wheels are supported by an area to be cleaned, e.g. a floor, the cleaner body ascends or descends along with the vertical movement of the wheel unit.

In the case in which the cleaner is equipped with a suspension unit for absorbing shocks applied to the wheel unit, the wheel unit is mounted to the suspension unit so as to be vertically movable. However, when the wheel unit ascends or descends in order to move the cleaner body upwards or downwards, the shock-absorbing performance of the suspension unit is degraded.

<CIT> relates to a vacuum cleaner having a detection switch detecting a protrusion state of a driving wheel with respect to a lower portion of a main body case by on and off of a switch main body being switched by rotation of a detection arm. A lever is provided in a rotatable manner and rotates the detection arm by rotation. A spring holds the detection arm at a position where the switch main body is switched to any of on and off by biasing the lever in a rotation direction. A lever section switches on and off of the switch main body of the detection switch by the lever rotating the detection arm by a driving wheel unit rotating in a downward direction and being positioned at a predetermined rotation position being rotated against bias of the spring.

An object of the present invention is to provide a cleaner in which a cleaner body is configured to be ascendable and descendable with respect to a suspension unit provided to absorb shocks applied to a wheel unit, thereby enabling the suspension unit to continuously absorb shocks even when the height of the cleaner body is adjusted.

Another object of the present invention is to provide a cleaner in which, when a cleaner body provided at the bottom surface thereof with a charging terminal is docked with an external docking device in order to charge a battery provided inside the cleaner body, the cleaner body ascends so that the charging terminal is located at a position enabling connection to the docking device.

A further object of the present invention is to provide a cleaner in which, when a cleaning nozzle having a suction port formed in the bottom surface thereof cleans a carpet, the cleaning nozzle ascends so as to prevent fibers of the carpet from being drawn into the suction port.

A further object of the present invention is to provide a cleaner in which, when an ascending/descending unit for allowing a cleaner body to ascend or descend is mounted to a suspension unit, the overall widths of the ascending/descending unit and the suspension unit are decreased, thereby securing space for disposing the ascending/descending unit in the cleaner body.

However, objects to be accomplished by the invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description.

The invention is specified by the independent claim. In accordance with the present invention, the above and other objects can be accomplished by the provision of a cleaner including a cleaner body, a wheel unit including a wheel configured to support the cleaner body so that the cleaner body travels on an area to be cleaned, a suspension unit, to which the wheel unit is mounted so as to be movable vertically, the suspension unit being configured to absorb shocks when the wheel unit moves vertically, and an ascending/descending unit mounted to the suspension unit so as to be ascendable and descendable and coupled to the cleaner body so as to ascend or descend together with the cleaner body.

The ascending/descending unit includes an ascending/descending drive motor, a first rotary bar configured to be rotated by torque of the ascending/descending drive motor, and at least one second rotary bar arranged perpendicular to the first rotary bar so as to be rotated by rotational force of the first rotary bar, the second rotary bar being mounted to the suspension unit so that the cleaner body ascends or descends along with rotation of the second rotary bar.

The ascending/descending unit may further include an ascending/descending housing in which the first rotary bar and the second rotary bar are rotatably mounted, the ascending/descending housing being coupled to the cleaner body so as to ascend or descend together with the second rotary bar.

The first rotary bar may be accommodated in the ascending/descending housing, and the second rotary bar may have one end portion protruding from the inside of the ascending/descending housing to the outside of the ascending/descending housing and inserted into the suspension unit.

The suspension unit may have therein an insertion hole, into which the one end portion of the second rotary bar is mounted via insertion, and threads formed in the inner circumferential surface of the insertion hole, and the second rotary bar may have threads formed in the outer circumferential surface of the one end portion of the second rotary bar so as to be meshed with the threads formed in the insertion hole.

The suspension unit may include a suspension frame, a guide bar mounted to the suspension frame so as to extend vertically, the wheel unit being mounted to the guide bar so as to be movable vertically, and an elastic member through which the guide bar passes, the elastic member being configured to absorb shocks when the wheel unit moves vertically. The insertion hole may be formed in the suspension frame.

The suspension unit may further include an insulator in which the insertion hole is formed, the insulator being coupled to the suspension frame.

The suspension frame may have therein an ascending/descending hole into which the ascending/descending drive motor is inserted, and the ascending/descending drive motor may be disposed outside the ascending/descending housing, and may ascend or descend within the ascending/descending hole when the ascending/descending unit ascends or descends.

The suspension frame may have a stepped portion formed such that a lower portion of a surface of the suspension frame that faces the interior of the cleaner body protrudes further than an upper portion thereof, and a portion of the ascending/descending housing, through which the second rotary bar protrudes to the outside of the ascending/descending housing, may be seated on the stepped portion when the ascending/descending unit descends.

The ascending/descending unit may further include a plurality of bearings for allowing the first rotary bar and the second rotary bar to be rotatably coupled to the ascending/descending housing.

The ascending/descending unit may further include a first worm disposed at a rotary shaft of the ascending/descending drive motor, a first worm wheel disposed at the first rotary bar and tooth-engaged with the first worm, a second worm disposed at the first rotary bar, and a second worm wheel disposed at the second rotary bar and tooth-engaged with the second worm.

The first worm wheel and the second worm may be formed integrally with the first rotary bar.

The second worm wheel may be formed integrally with the second rotary bar.

The at least one second rotary bar may include a plurality of second rotary bars, and the second rotary bars may be arranged parallel to each other.

The first rotary bar may be arranged in the horizontal direction, and the second rotary bar may be arranged in the vertical direction.

The cleaner may further include a sensing unit including at least one of an obstacle sensor, a floor sensor, or a position sensor, and a controller configured to perform control in response to sensed values transmitted from the sensing unit so that the ascending/descending unit ascends or descends.

The cleaner may further include a charging terminal having a predetermined configuration enabling connection to an external docking device for charging and disposed on the bottom surface of the cleaner body. When the cleaner body intends to be docked with the docking device, the controller may perform control such that the ascending/ descending unit ascends so that the cleaner body is moved upwards.

After the ascending/descending unit ascends, the controller may perform control such that the ascending/descending unit descends so that the cleaner body is moved downwards and the charging terminal is connected to the docking device.

The cleaner may further include a cleaning nozzle coupled to the cleaner body and having a suction port formed in the bottom surface thereof to suck foreign substances from an area to be cleaned. Upon determining that the area to be cleaned is a carpet based on information about the area to be cleaned sensed by the floor sensor, the controller may perform control such that the ascending/descending unit ascends so that the cleaning nozzle is moved upwards.

Upon determining that the cleaner body has left the carpet based on the information about the area to be cleaned, the controller may perform control such that the ascending/descending unit descends so that the cleaning nozzle is moved downwards.

Advantages and features of the present invention and methods for achieving them will be made clear from embodiments described below in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms, and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals represent the same components.

Hereinafter, a cleaner according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<FIG> is a perspective view illustrating a cleaner according to an embodiment of the present invention, and <FIG> is a view illustrating the cleaner from which a dust container depicted in <FIG> is separated.

Referring to <FIG> and <FIG>, a cleaner <NUM> includes a cleaner body <NUM>, a cleaning nozzle <NUM>, a sensing unit <NUM>, and a dust container <NUM>.

The cleaner <NUM> further includes various components including a controller (not illustrated) for controlling the cleaner <NUM>, which are embedded in or mounted on the cleaner body <NUM>. The cleaner body <NUM> may have therein a space formed to accommodate various components, which constitute the cleaner <NUM>, therein.

The cleaner body <NUM> is configured to travel in one of an automatic mode and a manual mode depending on a user's selection. The cleaner body <NUM> may be provided with a mode selection input unit, through which a user selects one of the automatic mode and the manual mode. When the user selects the automatic mode using the mode selection input unit, the cleaner body <NUM> may travel autonomously like a robot cleaner. When the user selects the manual mode using the mode selection input unit, the cleaner body <NUM> may travel by being manually drawn or pushed by the user.

The cleaner body <NUM> is provided with a wheel unit <NUM> for allowing the cleaner body <NUM> to travel. The wheel unit <NUM> may include a motor (not illustrated) and at least one wheel, which is configured to be rotated by the torque of the motor. The rotational direction of the motor may be controlled by the controller (not illustrated), and the wheel of the wheel unit <NUM> may be rotated in one direction or the opposite direction depending on the rotational direction of the motor.

The wheel unit <NUM> may be provided at each of the left and right sides of the cleaner body <NUM>. The cleaner body <NUM> may be moved or turned in all directions by the wheel unit <NUM>.

Each wheel unit <NUM> may be configured to be operated independently. To this end, each wheel unit <NUM> may be individually operated by a corresponding motor.

The controller controls the operation of the wheel unit <NUM> so that the cleaner <NUM> can travel autonomously on an area to be cleaned.

The wheel unit <NUM> is provided at the lower side of the cleaner body <NUM> so as to drive the cleaner body <NUM>. The wheel unit <NUM> may be constituted by circular wheels, may be constituted by circular rollers connected via a belt chain, or may be constituted by a combination of circular wheels and circular rollers connected via a belt chain. The wheel of the wheel unit <NUM> may be arranged such that the upper portion thereof is located inside the cleaner body <NUM> and the lower portion thereof is exposed downwards from the cleaner body <NUM>. At least the lower portion of the wheel of the wheel unit <NUM> is maintained in contact with an area to be cleaned, e.g. a floor, thereby driving the cleaner body <NUM>.

The wheel unit <NUM> may be mounted to each of the left and right sides of the cleaner body <NUM>. The wheel unit <NUM> disposed at the left side of the cleaner body <NUM> and the wheel unit <NUM> disposed at the right side of the cleaner body <NUM> may be operated independently of each other. The wheel unit <NUM> disposed at the left side of the cleaner body <NUM> may be connected to a first drive motor via at least one first gear. The first gear may be rotated by the torque of the first drive motor, and the wheel unit <NUM> disposed at the left side of the cleaner body <NUM> may also be rotated along with the rotation of the first gear. The wheel unit <NUM> disposed at the right side of the cleaner body <NUM> may be connected to a second drive motor via at least one second gear. The second gear may be rotated by the torque of the second drive motor, and the wheel unit <NUM> disposed at the right side of the cleaner body <NUM> may also be rotated along with the rotation of the second gear.

The controller may control the rotational speed of a rotary shaft of each of the first drive motor and the second drive motor so as to determine the direction in which the cleaner body <NUM> travels. For example, when the controller performs control such that the rotary shaft of the first drive motor and the rotary shaft of the second drive motor are simultaneously rotated at the same rotational speed as each other, the cleaner body <NUM> may travel straight. When the controller performs control such that the rotary shaft of the first drive motor and the rotary shaft of the second drive motor are simultaneously rotated at different rotational speeds from each other, the cleaner body <NUM> may turn to the left or right. In order to make the cleaner body <NUM> turn to the left or right, the controller may operate one of the first drive motor and the second drive motor and may stop the operation of the other.

The cleaner <NUM> may further include a suspension unit, which may be mounted in the cleaner body <NUM>. The suspension unit may include a coil spring. The suspension unit may serve to absorb shocks and vibrations, which are transmitted to the wheel unit <NUM> while the cleaner body <NUM> travels, using the elastic force of the coil spring.

In addition, the cleaner <NUM> may further include an ascending/descending unit, which is mounted to the suspension unit in order to adjust the height of the cleaner body <NUM>. The ascending/descending unit may be mounted to the suspension unit so as to be movable upwards or downwards, and may be coupled to the cleaner body <NUM>. Therefore, when the ascending/descending unit moves upwards in the suspension unit, the cleaner body <NUM> may also move upwards along with the ascending/descending unit, and when the ascending/descending unit moves downwards in the suspension unit, the cleaner body <NUM> may also move downwards along with the ascending/descending unit. The cleaner body <NUM> is moved upwards or downwards by the ascending/descending unit, whereby the height thereof is adjusted.

When the cleaner body <NUM> travels on a hard floor to clean the same, the wheel of the wheel unit <NUM> and the bottom of the cleaning nozzle <NUM> are maintained in close contact with the floor. However, when the cleaner body <NUM> travels on a carpet laid over the floor, the wheel of the wheel unit <NUM> may slip, and thus the traveling performance of the cleaner body <NUM> may be degraded. In addition, the cleaning nozzle <NUM> may draw the carpet with a certain suction force, and this suction force applied between the cleaning nozzle <NUM> and the carpet may degrade the traveling performance of the cleaner body <NUM>.

In order to solve this problem, the ascending/descending unit adjusts the height of the cleaner body <NUM> depending on the slip rate of the wheel of the wheel unit <NUM>, and consequently the degree of contact between the bottom of the cleaning nozzle <NUM> and an area to be cleaned can be adjusted. Accordingly, it is possible to maintain the traveling performance of the cleaner body <NUM> regardless of the material of the area to be cleaned.

As described above, the wheel of the wheel unit <NUM> disposed at the left side of the cleaner body <NUM> is connected to the first drive motor via the first gear, and the wheel of the wheel unit <NUM> disposed at the right side of the cleaner body <NUM> is connected to the second drive motor via the second gear. In this configuration, when the first drive motor and the second drive motor are stationary, the wheel of the wheel unit <NUM> disposed at each of the left and right sides of the cleaner body <NUM> is not allowed to rotate. In this state, the user cannot drive the cleaner body <NUM> in a manual mode. Therefore, when the cleaner body <NUM> is driven in the manual mode, the connection between the wheel of the wheel unit <NUM> disposed at each of the left and right sides of the cleaner body <NUM> and a corresponding one of the first and second drive motors should be released. To this end, the cleaner <NUM> may further include a clutch, which is provided inside the cleaner body <NUM> and which connects the wheel of the wheel unit <NUM> disposed at each of the left and right sides of the cleaner body <NUM> and a corresponding one of the first and second drive motors when the cleaner body <NUM> is driven in the automatic mode, and releases the connection between the wheel of the wheel unit <NUM> disposed at each of the left and right sides of the cleaner body <NUM> and a corresponding one of the first and second drive motors when the cleaner body <NUM> is driven in the manual mode.

The cleaner <NUM> may further include a battery (not illustrated), which is mounted to the cleaner body <NUM> in order to supply electrical power to electrical components of the cleaner <NUM>. The battery may be configured to be rechargeable, and may be detachably mounted to the cleaner body <NUM>.

A dust container accommodation unit <NUM> is provided in the cleaner body <NUM>. The dust container <NUM>, which separates foreign substances from the sucked air and collects the foreign substances therein, is detachably coupled to the dust container accommodation unit <NUM>.

The dust container accommodation unit <NUM> may be formed to have a shape that is opened forwards and upwards from the cleaner body <NUM> and that is indented from the front side of the cleaner body <NUM> toward the rear side of the cleaner body <NUM>. Alternatively, the dust container accommodation unit <NUM> may be formed in a shape in which the front side of the cleaner body <NUM> is opened forwards, upwards and downwards.

The dust container accommodation unit <NUM> may be formed at the other side of the cleaner body <NUM> (for example, the rear side of the cleaner body <NUM>) depending on the kind of cleaner.

The dust container <NUM> is detachably coupled to the dust container accommodation unit <NUM>. A portion of the dust container <NUM> may be accommodated in the dust container accommodation unit <NUM>, and the remaining portion of the dust container <NUM> may be formed to protrude from the cleaner body <NUM> in the forward direction.

The dust container <NUM> includes an inlet <NUM>, through which air containing foreign substances such as dust is introduced, and an outlet <NUM>, through which air from which dust has been separated is discharged. When the dust container <NUM> is mounted in the dust container accommodation unit <NUM>, the inlet <NUM> and the outlet <NUM> formed in the dust container <NUM> respectively communicate with a first opening <NUM> and a second opening <NUM> formed in an inner wall of the dust container accommodating unit <NUM>.

An intake flow passage formed in the cleaner body <NUM> corresponds to a flow passage formed from the cleaning nozzle <NUM> to the first opening <NUM>, and an exhaust flow passage formed in the cleaner body <NUM> corresponds to a flow passage formed from the second opening <NUM> to an exhaust port.

Due to this air flow connection relationship, air containing foreign substances, which is introduced through the cleaning nozzle <NUM>, is introduced into the dust container <NUM> via the intake flow passage in the cleaner body <NUM>, and the foreign substances are separated from the sucked air while passing through at least one filtering member (for example, a cyclone, a filter, etc.) provided in the dust container <NUM>. The foreign substances are collected in the dust container <NUM>, and the air is discharged from the dust container <NUM>. The filtered air is discharged to the outside through the exhaust port after passing through the exhaust flow passage in the cleaner body <NUM>.

The cleaner body <NUM> is provided with an upper cover <NUM>, which is configured to cover the dust container <NUM> accommodated in the dust container accommodation unit <NUM>. The upper cover <NUM> may be hinged to a portion of the cleaner body <NUM> so as to be rotatable. The upper cover <NUM> may cover the upper side of the dust container <NUM> by covering the opened upper side of the dust container accommodation unit <NUM>. In addition, the upper cover <NUM> may be configured to be separable from the cleaner body <NUM>.

In the state in which the upper cover <NUM> covers the dust container <NUM>, the dust container <NUM> may be prevented from being separated from the dust container accommodation unit <NUM>.

The upper cover <NUM> is provided at the upper side thereof with a handle <NUM>. The handle <NUM> may be provided with an image-capturing unit <NUM>. It is desirable for the image-capturing unit <NUM> to be arranged at an incline with respect to the bottom surface of the cleaner body <NUM> so as to capture an image of the surroundings ahead of and above the cleaner body <NUM>.

The image-capturing unit <NUM> may be provided at the cleaner body <NUM>, and may serve to capture an image for simultaneous localization and mapping (SLAM) of the cleaner. The image captured by the image-capturing unit <NUM> is used to generate a map of a traveling area or to detect the current position within the traveling area.

The image-capturing unit <NUM> may generate three-dimensional coordinate information related to the surroundings of the cleaner body <NUM>. This image-capturing unit <NUM> may be a three-dimensional depth camera, which calculates the distance between the cleaner <NUM> and an object to be photographed. Accordingly, field data related to the three-dimensional coordinate information may be generated.

Specifically, the image-capturing unit <NUM> may capture a two-dimensional image related to the surroundings of the cleaner body <NUM>, and may generate a plurality of pieces of three-dimensional coordinate information that corresponds to the captured two-dimensional image.

In one embodiment, the image-capturing unit <NUM> may include two or more cameras for capturing two-dimensional images, thereby forming a stereo vision system, in which two or more images captured by the two or more cameras are combined and three-dimensional coordinate information corresponding thereto is generated.

Specifically, the image-capturing unit <NUM> according to the embodiment may include a first pattern emission unit, which emits light in a first pattern in a forward-and-downward direction from the cleaner body, a second pattern emission unit, which emits light in a second pattern in a forward-and-upward direction from the cleaner body, and an image acquisition unit, which acquires an image of the surroundings ahead of the cleaner body. Accordingly, the image acquisition unit acquires an image of a region to which the light in the first pattern and the light in the second pattern are emitted.

In another embodiment, the image-capturing unit <NUM> may include a single camera and an infrared pattern projection unit for projecting an infrared pattern. In this case, the distance between the image-capturing unit <NUM> and an object to be photographed may be measured by capturing the shape of the infrared pattern projected on the object to be photographed from the infrared pattern projection unit. This image-capturing unit <NUM> may be an infrared (IR)-type image-capturing unit.

In a further embodiment, the image-capturing unit <NUM> may include a single camera and a light-emitting unit for emitting light. In this case, the distance between the image-capturing unit <NUM> and an object to be photographed may be measured by receiving a portion of a laser beam that is reflected from the object to be photographed after being emitted from the light-emitting unit and analyzing the received laser beam. This image-capturing unit <NUM> may be a time-of-flight (TOF)-type image-capturing unit.

Specifically, the image-capturing unit <NUM> may include a laser that is configured to emit a laser beam in at least one direction. For example, the image-capturing unit <NUM> may include a first laser and a second laser. The first laser may emit linear laser beams that intersect each other, and the second laser may emit a linear laser beam. In this case, the lowermost laser is used to sense an obstacle located at a relatively low position on an area to be cleaned, the uppermost laser is used to sense an obstacle located at a relatively high position, and the intermediate laser, which is disposed between the lowermost laser and the uppermost laser, is used to sense an obstacle located at an intermediate position.

The sensing unit <NUM> may be disposed at the lower side of the upper cover <NUM>, and may be detachably coupled to the dust container <NUM>.

The sensing unit <NUM> is disposed at the cleaner body <NUM>, and detects information related to the surroundings of the cleaner body <NUM>. The sensing unit <NUM> detects information related to the surroundings in order to generate field data.

The sensing unit <NUM> senses the surroundings (including obstacles) of the cleaner <NUM> in order to prevent the cleaner <NUM> from colliding with obstacles. The sensing unit <NUM> may detect information related to the surroundings of the cleaner <NUM>. The sensing unit <NUM> may sense the presence of a user around the cleaner <NUM>. The sensing unit <NUM> may sense the presence of objects around the cleaner <NUM>.

In addition, in order to improve the sensing function and the traveling function of the cleaner, the sensing unit <NUM> is configured so as to turn in the horizontal direction (i.e. panning) and in the vertical direction (i.e. tilting).

The sensing unit <NUM> is disposed at the front side of the cleaner body <NUM> and between the dust container <NUM> and the upper cover <NUM>. The sensing unit <NUM> includes a coupling protrusion 132d, which protrudes from the bottom surface of the sensing unit <NUM>, and the dust container <NUM> includes a coupling recess <NUM>, which is formed in the top surface of the dust container <NUM> and into which the coupling protrusion 132d of the sensing unit <NUM> is inserted and coupled. When the upper cover <NUM> covers the top of the dust container accommodation unit <NUM>, the coupling protrusion 132d of the sensing unit <NUM> is inserted into the coupling recess <NUM> in the dust container <NUM>. In this way, the dust container <NUM> is coupled to the sensing unit <NUM>, with the result that the dust container <NUM> is prevented from being separated from the cleaner body <NUM>. Conversely, when the upper cover <NUM> opens the top of the dust container accommodation unit <NUM>, the coupling protrusion 132d of the sensing unit <NUM> escapes from the coupling recess <NUM> in the dust container <NUM>. Accordingly, the coupling between the dust container <NUM> and the sensing unit <NUM> is released, and thus the dust container <NUM> becomes separable from the cleaner body <NUM>.

The sensing unit <NUM> may include at least one of an external signal sensor, an obstacle sensor, a cliff sensor, a lower camera sensor, an upper camera sensor, an encoder, a shock sensor, or a microphone.

The external signal sensor may sense an external signal of the cleaner <NUM>. The external signal sensor may be, for example, an infrared ray sensor, an ultrasonic sensor, a radio frequency (RF) sensor, or the like. Accordingly, field data related to an external signal may be generated.

The cleaner <NUM> may receive a guide signal generated from the charging stand using the external signal sensor, and may detect information related to the location thereof and the direction to the charging stand. The charging stand may transmit a guide signal for indicating the direction and distance, based on which the cleaner <NUM> can return to the charging stand. That is, the cleaner <NUM> determines the current location thereof and the direction to the charging stand by receiving a signal transmitted from the charging stand, and returns to the charging stand.

The obstacle sensor may sense an obstacle present ahead of the cleaner. Accordingly, field data related to an obstacle may be generated.

The obstacle sensor may transmit field data, which is generated by sensing an object present in a region toward which the cleaner <NUM> is directed, to the controller. That is, the obstacle sensor may sense a protrusion, domestic items, furniture, a wall surface, a wall corner, etc. that are present in a path through which the cleaner <NUM> moves, and may transmit related field data to the controller.

The obstacle sensor may be, for example, an infrared ray sensor, an ultrasonic sensor, an RF sensor, a geomagnetic sensor, or the like. The cleaner <NUM> may use one type of sensor as the obstacle sensor, or may use two or more types of sensors in combination as the obstacle sensor as needed.

The cliff sensor may primarily use various types of optical sensors, and may sense an obstacle, which is present in an area to be cleaned on which the cleaner body <NUM> is supported. Accordingly, field data related to an obstacle present in an area to be cleaned may be generated.

The cliff sensor may be, for example, an infrared ray sensor including a light-emitting unit and a light-receiving unit, an ultrasonic sensor, an RF sensor, a position-sensitive detector (PSD) sensor, or the like, like the obstacle sensor.

For example, the cliff sensor may be a PSD sensor. However, the cliff sensor may be configured as different types of sensors. The PSD sensor may include a light-emitting unit, which emits an infrared ray toward an obstacle, and a light-receiving unit, which receives an infrared ray that is reflected and returns from the obstacle, and may be typically configured in a modular form. In the case in which an obstacle is sensed by a PSD sensor, it is possible to obtain a stable measurement value irrespective of a difference in the reflectance or in the color of an obstacle.

The controller measures an angle of an infrared ray between a light emission signal generated when the cliff sensor emits an infrared ray toward the surface of an area to be cleaned and a reflection signal generated when the cliff sensor receives an infrared ray reflected from an obstacle, thereby sensing the presence of a cliff and obtaining field data related to the depth of the cliff.

The lower camera sensor obtains image information (field data) about the surface of an area to be cleaned while the cleaner <NUM> is moving. The lower camera sensor is alternatively referred to using the term "optical flow sensor". The lower camera sensor may convert a lower-side image, which is received from an image sensor provided inside the sensor, and may generate predetermined type of image data (field data). As such, field data related to the image recognized through the lower camera sensor may be generated.

The controller may detect a location of the cleaner using the lower camera sensor regardless of slippage of the cleaner. The controller may compare and analyze image data captured by the lower camera sensor over time, may calculate a moving distance and a moving direction thereof, and consequently may calculate a location of the cleaner.

The cliff sensor may also sense the material of an area to be cleaned. The cliff sensor may sense the amount of light reflected (reflectance) from the area to be cleaned, and the controller may determine the material of the area to be cleaned based on the sensed reflectance. For example, in the case in which the material of the area to be cleaned is stone, e.g. marble, which has high reflectance, the cliff sensor may sense a relatively large amount of reflected light (high reflectance), and in the case in which the material of the area to be cleaned is wood, oilpaper, or textile (e.g. carpet), which has lower reflectance than marble, the cliff sensor may sense a relatively small amount of reflected light (low reflectance). As such, the controller may determine the material of the area to be cleaned using the reflectance of the area to be cleaned that is sensed by the cliff sensor. If the reflectance of the area to be cleaned is a predetermined value, the controller may determine that the area to be cleaned is a carpet.

In addition, the cliff sensor may sense the distance to the area to be cleaned, and the controller may determine the material of the area to be cleaned based on the sensed distance to the area to be cleaned. For example, when the cleaner is located on a carpet laid over a floor, the distance to the area to be cleaned, i.e. the carpet, which is sensed by the cliff sensor, may be shorter than when the cleaner is located on a floor on which no carpet is laid. As such, the controller may determine the material of the area to be cleaned using the distance to the area to be cleaned that is sensed by the cliff sensor. If the distance to the area to be cleaned is a predetermined value or less, the controller may determine that the area to be cleaned is a carpet.

Various sensors, e.g. a camera sensor, a current sensor, etc., other than the cliff sensor, may be used as the sensor for sensing the state of the area to be cleaned.

The camera sensor may capture an image of the area to be cleaned, and the controller may determine the material of the area to be cleaned by analyzing the image captured by the camera sensor. Images of various materials may be stored in the controller in advance, and when the image captured by the camera sensor corresponds to one of the images stored in the controller, the controller may determine the material of the area to be cleaned to be a material in the corresponding image. If the image captured by the camera sensor coincides with an image of a carpet stored in the controller, the controller may determine that the area to be cleaned is a carpet.

The current sensor may sense a current resistance value of the wheel drive motor, and the controller may determine the material of the area to be cleaned based on the current resistance value sensed by the current sensor. For example, when the cleaning nozzle <NUM> is located on a carpet laid over a floor, fibers of the carpet may be drawn into the suction port by the suction force of the cleaning nozzle <NUM>, and this suction force applied between the carpet and the suction port may prevent the cleaner from traveling smoothly. At this time, current resistance may be generated due to a load between a rotor and a stator of the wheel drive motor. The current sensor may sense the current resistance value that is generated in the wheel drive motor, and the controller may determine the material of the area to be cleaned based on the current resistance value. If the current resistance value is a predetermined value or more, the controller may determine that the area to be cleaned is a carpet.

The upper camera sensor may be mounted so as to be oriented in an upward direction or a forward direction from the cleaner <NUM>, and may capture an image of the surroundings of the cleaner <NUM>. In the case in which the cleaner <NUM> is provided with a plurality of upper camera sensors, the camera sensors may be arranged on the top surface or the side surface of the cleaner at regular intervals or angles. Field data related to the image recognized through the upper camera sensor may be generated.

The encoder may detect information related to the operation of the motor for operating the wheel of the wheel unit <NUM>. Accordingly, field data related to the operation of the motor may be generated.

The shock sensor may sense shocks generated when the cleaner <NUM> collides with an external obstacle or the like. Accordingly, field data related to the external shocks may be generated.

The microphone may sense an external sound. Accordingly, field data related to the external sound may be generated.

In this embodiment, the sensing unit <NUM> includes an image sensor. In this embodiment, the field data is image information acquired by the image sensor or feature point information extracted from the image information. However, the present invention is not limited thereto.

An adapter <NUM> may be disposed at the opened lower side of the dust container accommodation unit <NUM>. The adapter <NUM> is coupled to the cleaner body <NUM> so as to constitute a part of the cleaner body <NUM>. That is, in the state in which the adapter <NUM> is coupled to the cleaner body <NUM>, the adapter <NUM> may be considered to be a part of the cleaner body <NUM>. The dust container <NUM>, in which foreign substances are stored, may be seated on the adapter <NUM>. The adapter <NUM> may serve to interconnect the cleaner body <NUM> and the cleaning nozzle <NUM>. The adapter <NUM> may interconnect an intake flow passage in the cleaner body <NUM> and an intake flow passage in the cleaning nozzle <NUM>.

The cleaning nozzle <NUM> is configured to suck air containing foreign substances such as dust or to wipe the area to be cleaned. The cleaning nozzle <NUM> for sucking air containing foreign substances may be referred to as a suction module, and the cleaning nozzle <NUM> for wiping the area to be cleaned may be referred to as a mop module.

The cleaning nozzle <NUM> may be detachably coupled to the cleaner body <NUM>. If the suction module is separated from the cleaner body <NUM>, the mop module may be detachably coupled to the cleaner body <NUM> instead of the separated suction module. Therefore, when the user wants to remove foreign substances such as dust from the area to be cleaned, the user may install the suction module to the cleaner body <NUM>, and when the user wants to wipe the area to be cleaned, the user may install the mop module to the cleaner body <NUM>.

The cleaning nozzle <NUM> may be configured to perform both the function of sucking air containing foreign substances such as dust and the function of wiping the area to be cleaned after the suction.

The cleaning nozzle <NUM> may be disposed at the lower side of the cleaner body <NUM>. Alternatively, as illustrated, the cleaning nozzle <NUM> may be disposed so as to protrude from a portion of the cleaner body <NUM>. The portion of the cleaner body <NUM> from which the cleaning nozzle <NUM> protrudes may be a portion of the cleaner body <NUM> that is oriented in the direction in which the cleaner body <NUM> advances, i.e. the front side of the cleaner body <NUM>. The cleaning nozzle <NUM> may be disposed at a position further forward than the wheel unit <NUM> so that a portion thereof may protrude forward from the dust container <NUM>.

As illustrated, the cleaning nozzle <NUM> protrudes in the forward direction, the leftward direction and the rightward direction from a portion of the cleaner body <NUM>. Specifically, the front end of the cleaning nozzle <NUM> is located at a position spaced apart from the portion of the cleaner body <NUM> in the forward direction, and the left and right sides of the cleaning nozzle <NUM> are respectively located at positions spaced apart from the portion of the cleaner body <NUM> in the leftward and rightward directions.

A suction motor may be mounted inside the cleaner body <NUM>. An impeller (not illustrated) may be coupled to a rotary shaft of the suction motor. When the suction motor is operated and the impeller is rotated along with the rotation of the rotary shaft, the impeller may generate suction force.

An intake flow passage may be formed inside the cleaner body <NUM>. Foreign substances such as dust may be introduced into the cleaning nozzle <NUM> from the area to be cleaned by the suction force generated by the drive force of the suction motor, and the foreign substances introduced into the cleaning nozzle <NUM> may be introduced into the intake flow passage.

In the case in which the cleaner body <NUM> travels in the automatic mode, the cleaning nozzle <NUM> may perform cleaning on the area to be cleaned, e.g. a floor. The cleaning nozzle <NUM> may be disposed at a portion of the front side of the cleaner body <NUM> that is adjacent to the floor. The cleaning nozzle <NUM> may have a suction port, which is formed at the bottom surface of the cleaning nozzle <NUM> in order to suck air thereinto. The suction port may be formed so as to be oriented toward the floor when the cleaning nozzle <NUM> is coupled to the cleaner body <NUM>.

The cleaning nozzle <NUM> may be coupled to the cleaner body <NUM> via the adapter <NUM>. The cleaning nozzle <NUM> may communicate with the intake flow passage in the cleaner body <NUM> via the adapter <NUM>. The cleaning nozzle <NUM> may be disposed at a position further downward than the dust container <NUM> disposed at the front side of the cleaner body <NUM>.

The cleaning nozzle <NUM> may include a case, which has a suction port formed at the bottom surface thereof. A brush unit may be rotatably provided inside the case. The case may provide an empty space in which the brush unit is rotatably provided. The brush unit may include a rotary shaft, which extends in the lateral direction, and a brush, which protrudes from the outer circumferential surface of the rotary shaft. The rotary shaft of the brush unit may be rotatably coupled to the left side and the right side of the case.

The case of the cleaning nozzle <NUM> may include a center case <NUM> and side cases <NUM>, which are disposed at the left and right sides of the center case <NUM> in order to form the left surface and the right surface of the cleaning nozzle <NUM>. The suction port may be formed at the bottom surface of the center case <NUM>. The center case <NUM> may have open left and right sides, and the side cases <NUM> may be coupled to the open left and right sides of the center case <NUM> and may shield the same.

The brush unit may be disposed such that the brush is exposed downwards through the suction port formed at the bottom surface of the case. Accordingly, when the suction motor is operated, the brush is rotated by the suction force and sweeps foreign substances such as dust up from the area to be cleaned, e.g. a floor. The swept-up foreign substances are sucked into the case by the suction force. To this end, the brush may be made of a material in which frictional electricity is not generated in order to prevent foreign substances from easily adhering to the brush.

The adapter <NUM> may be coupled to the front side of the cleaner body <NUM>. The adapter <NUM> may interconnect the cleaner body <NUM> and the cleaning nozzle <NUM>. The cleaning nozzle <NUM> may be detachably coupled to the adapter <NUM>. The adapter <NUM> may support the lower side of the dust container <NUM>.

The dust container <NUM> may be detachably coupled to the front side of the cleaner body <NUM>, and the lower side thereof may be supported by the adapter <NUM>. The dust container <NUM> may include a case, which has a hollow cylindrical shape. A filtering unit, which separates foreign substances from the air sucked through the intake flow passage in the cleaner body <NUM>, may be disposed inside the cylindrical-shaped case. The filtering unit may include a plurality of cyclones. The foreign substances, such as dust, filtered by the filtering unit, may drop into the dust container <NUM>, and may be contained in the dust container <NUM>. Only air may escape out of the dust container <NUM>, may be moved toward the suction motor by the suction force of the suction motor, and may finally be discharged outside the cleaner body <NUM>.

The dust container <NUM> may have an open lower surface, and the open lower surface of the dust container <NUM> may be shielded by a lid <NUM>. The lid <NUM> may be rotatably coupled at a portion thereof to the dust container <NUM> in order to open or close the dust container <NUM>. When the lid <NUM> is opened, the open lower surface of the dust container <NUM> may be exposed, and the foreign substances contained in the dust container <NUM> may drop through the open lower surface of the dust container <NUM>. A user can throw away the foreign substances contained in the dust container <NUM> by separating the dust container <NUM> from the cleaner body <NUM> and opening the lid <NUM>. In the state in which the dust container <NUM> is coupled to the cleaner body <NUM>, the dust container <NUM> is seated on the adapter <NUM>. That is, the lid of the dust container <NUM> is seated on the adapter <NUM>.

As described above, when the cleaner body <NUM> travels on the area to be cleaned, e.g. a floor, in the automatic mode, the cleaning nozzle <NUM> may perform cleaning automatically while closely contacting the floor. However, when the user wants to perform cleaning manually, the user may select the manual mode using the mode selection input unit provided at the cleaner body <NUM>, may separate the cleaning nozzle <NUM> from the cleaner body <NUM>, and may couple a manual cleaning nozzle to the cleaner body <NUM>, thereby performing cleaning manually. The manual cleaning nozzle may include a long bellows-type hose. In this case, a portion of the hose of the manual cleaning nozzle may be connected to the cleaner body <NUM>.

As described above, the cleaner according to the embodiment of the present invention may include the suspension unit for absorbing shocks applied to the wheel unit <NUM> and the ascending/descending unit for adjusting the height of the cleaner body <NUM>. In order to enable the suspension unit to continuously absorb shocks applied to the wheel unit <NUM> even while the ascending/descending unit adjusts the height of the cleaner body <NUM>, the ascending/descending unit is mounted to the suspension unit so as to be movable vertically, and is coupled to the cleaner body <NUM>. A detailed description of this configuration will now be made with reference to <FIG>.

<FIG> is a front view illustrating the wheel unit depicted in <FIG> and <FIG>, the suspension unit coupled to the wheel unit, and the ascending/descending unit mounted to the suspension unit. <FIG> is a front perspective view of <FIG>, from which a wheel cover and a travel belt are removed. <FIG> is a rear perspective view of <FIG>, which illustrates the state in which the ascending/descending unit is moved to the lowermost position. <FIG> is a rear perspective view of <FIG>, which illustrates the state in which the ascending/descending unit is moved to the uppermost position. <FIG> is a view illustrating the configuration of an ascending/descending housing depicted in <FIG>.

Referring to <FIG>, the cleaner <NUM> according to the present invention includes the wheel unit <NUM>, the suspension unit <NUM>, and the ascending/descending unit <NUM>. The wheel unit <NUM> and the suspension unit <NUM> may be coupled to each other so as to constitute a drive unit <NUM> and <NUM>. In other words, the drive unit <NUM> and <NUM> may include the wheel unit <NUM> and the suspension unit <NUM>. The wheel unit <NUM> is disposed outside the cleaner body <NUM>. The suspension unit <NUM> is disposed at a position further inward than the wheel unit <NUM>. The ascending/descending unit <NUM> is disposed at a position further inward than the suspension unit <NUM>. That is, the wheel unit <NUM>, the suspension unit <NUM> and the ascending/descending unit <NUM> are arranged from the outside of the cleaner body <NUM> in the inward direction of the cleaner body <NUM> in that order. The ascending/descending unit <NUM> may be coupled to the cleaner body <NUM>, the suspension unit <NUM> may be coupled to the ascending/descending unit <NUM> in a suspended manner, and the wheel unit <NUM> may be coupled to the suspension unit <NUM> in a suspended manner. The wheel unit <NUM> may be mounted to one surface, e.g. the outer surface, of the suspension unit <NUM> so as to be movable vertically, and the ascending/descending unit <NUM> may be mounted to the opposite surface, e.g. the inner surface, of the suspension unit <NUM> so as to be ascendable and descendable.

The wheel unit <NUM> is mounted to each of the left and right sides of the cleaner body <NUM> so that the cleaner body <NUM> can travel. The wheel unit <NUM> includes a travel drive motor <NUM>, at least one wheel <NUM> and <NUM>, which is configured to be rotated by the torque of the travel drive motor <NUM> to drive the cleaner body <NUM>, and a gear housing <NUM>, to which the travel drive motor <NUM> and the wheel <NUM> and <NUM> are mounted. The travel drive motor <NUM> may be fixed to the outer side of the gear housing <NUM>. A rotary shaft of the travel drive motor <NUM> may be inserted from the outside of the gear housing <NUM> into the gear housing <NUM>.

The at least one wheel <NUM> and <NUM> may support the cleaner body <NUM> so that the cleaner body <NUM> is movable on the area to be cleaned. In this embodiment, the wheel <NUM> and <NUM> includes a drive wheel <NUM>, which is disposed at the front side of the gear housing <NUM>, and a driven wheel <NUM>, which is disposed so as to be spaced apart from the drive wheel <NUM> in the backward direction. The drive wheel <NUM> and the driven wheel <NUM> may be connected to each other via a travel belt <NUM>. The drive wheel <NUM> includes a plurality of protrusions, which are formed on the outer circumferential surface of the drive wheel <NUM> and are arranged in the circumferential direction of the drive wheel <NUM>. The travel belt <NUM> includes a plurality of recesses, which are formed in the inner circumferential surface of the travel belt <NUM> so as to allow the protrusions formed on the outer circumferential surface of the drive wheel <NUM> to be inserted thereinto. Due to the coupling structure in which the protrusions are inserted into the recesses, when the drive wheel <NUM> rotates, the travel belt <NUM> is rotated without slipping, and consequently the driven wheel <NUM> is rotated.

The wheel unit <NUM> may further include a plurality of gears (not illustrated), which are disposed inside the gear housing <NUM> to connect the rotary shaft of the travel drive motor <NUM> and the drive wheel <NUM>. In this case, the torque of the travel drive motor <NUM> rotates the gears disposed inside the gear housing <NUM>, and the drive wheel <NUM>, the travel belt <NUM> and the driven wheel <NUM> are rotated sequentially. A wheel cover <NUM> may be coupled to the gear housing <NUM> to shield the drive wheel <NUM> and the driven wheel <NUM>. The drive wheel <NUM> and the driven wheel <NUM> may be disposed between the gear housing <NUM> and the wheel cover <NUM>. One end of each of the drive wheel <NUM> and the driven wheel <NUM> may be rotatably coupled to the gear housing <NUM>, and the other end of each of the drive wheel <NUM> and the driven wheel <NUM> may be rotatably coupled to the wheel cover <NUM>.

The main feature of the cleaner <NUM> according to the embodiment of the present invention is to adjust the height of the cleaner body <NUM>. Therefore, the wheel unit <NUM> is merely configured to allow the cleaner body <NUM> to travel and to be mounted to the suspension unit <NUM> so as to be movable vertically. That is, the wheel unit <NUM> may be formed in any of various configurations, as long as the wheel unit <NUM> includes at least one of a wheel or a belt, which is directly supported by the area to be cleaned, e.g. a floor, and is rotated, and as long as the wheel unit <NUM> is mounted to the suspension unit <NUM> so as to be movable vertically.

The suspension unit <NUM> absorbs shocks transmitted from the wheel unit <NUM> while the cleaner body <NUM> travels. The suspension unit <NUM> includes a suspension frame <NUM>, guide bars <NUM> and <NUM>, and elastic members <NUM> and <NUM>.

The gear housing <NUM> includes bar-mounting portions <NUM> and <NUM>, which are mounted to the guide bars <NUM> and <NUM> of the suspension unit <NUM> so as to be movable vertically. Since the bar-mounting portions <NUM> and <NUM> are mounted to the guide bars <NUM> and <NUM> so as to be movable vertically, the wheel unit <NUM> is mounted to the suspension unit <NUM> so as to be movable vertically. The guide bars <NUM> and <NUM> penetrate the bar-mounting portions <NUM> and <NUM> vertically. The bar-mounting portions <NUM> and <NUM> have therein through-holes that the guide bars <NUM> and <NUM> penetrate vertically. Each of the bar-mounting portions <NUM> and <NUM> is formed at a respective one of the front side and the rear side of the gear housing <NUM>. That is, the bar-mounting portions <NUM> and <NUM> include a front bar-mounting portion <NUM>, which is disposed at the front side of the gear housing <NUM>, and a rear bar-mounting portion <NUM>, which is disposed at the rear side of the gear housing <NUM>. The guide bars <NUM> and <NUM> of the suspension unit <NUM> are two in number, namely, a front guide bar <NUM>, which is disposed at the front side of the suspension unit <NUM>, and a rear guide bar <NUM>, which is disposed at the rear side of the suspension unit <NUM>. The front bar-mounting portion <NUM> is mounted to the front guide bar <NUM> so as to be movable vertically, and the rear bar-mounting portion <NUM> is mounted to the rear guide bar <NUM> so as to be movable vertically.

The guide bars <NUM> and <NUM> are mounted to the outer surface of the suspension frame <NUM> so as to extend vertically. The front guide bar <NUM> is disposed at the front side of the outer surface of the suspension frame <NUM>, and the rear guide bar <NUM> is disposed at the rear side of the outer surface of the suspension frame <NUM>.

The elastic members <NUM> and <NUM> are configured as coil springs, through which the guide bars <NUM> and <NUM> pass vertically. The upper ends of the elastic members <NUM> and <NUM> are supported by the suspension frame <NUM>, and the lower ends of the elastic members <NUM> and <NUM> are supported by the bar-mounting portions <NUM> and <NUM>. If shocks are applied to the cleaner body <NUM> or to the wheel unit <NUM> while the cleaner body <NUM> travels, the elastic members <NUM> and <NUM> absorb the shocks by being compressed. Since the bar-mounting portions <NUM> and <NUM> of the wheel unit <NUM> are movably mounted to the guide bars <NUM> and <NUM> so as to support the lower sides of the elastic members <NUM> and <NUM>, the suspension unit <NUM> absorbs shocks when the wheel unit <NUM> moves vertically. The elastic members <NUM> and <NUM> include a front elastic member <NUM>, through which the front guide bar <NUM> passes vertically and the lower end of which is supported by the front bar-mounting portion, and a rear elastic member <NUM>, through which the rear guide bar <NUM> passes vertically and the lower end of which is supported by the rear bar-mounting portion.

The ascending/descending unit <NUM> may be coupled to the cleaner body <NUM>. The ascending/descending unit <NUM> may be configured to ascend or descend together with the cleaner body <NUM>, and may be mounted to the drive unit <NUM> and <NUM> so as to be ascendable and descendable. The ascending/descending unit <NUM> may be mounted to the suspension unit <NUM> of the drive unit <NUM> and <NUM> so as to be ascendable and descendable. The cleaner body <NUM> ascends or descends along with the vertical movement of the ascending/descending unit <NUM>, with the result that the height of the cleaner body <NUM> is adjusted.

The ascending/descending unit <NUM> may include an ascending/descending drive motor <NUM>, a first rotary bar <NUM>, and a second rotary bar <NUM> and <NUM>. The first rotary bar <NUM> may be rotated by the torque of the ascending/descending drive motor <NUM>. The second rotary bar <NUM> and <NUM> may be arranged perpendicular to the first rotary bar <NUM>. The first rotary bar <NUM> may be arranged so as to extend horizontally, specifically, in the forward-and-backward direction, and the second rotary bar <NUM> and <NUM> may be arranged so as to extend vertically. The second rotary bar <NUM> and <NUM> may be rotated by the rotational force of the first rotary bar <NUM>, and may be mounted to the suspension unit <NUM> so that the cleaner body <NUM> ascends or descends along with the rotation of the second rotary bar <NUM> and <NUM>.

The second rotary bar <NUM> and <NUM> may be provided in a plural number, and the plurality of second rotary bars <NUM> and <NUM> may be arranged parallel to each other. In this embodiment, the second rotary bars <NUM> and <NUM> are two in number, which includes a second front rotary bar <NUM>, which is disposed at the front side of the first rotary bar <NUM>, and a second rear rotary bar <NUM>, which is disposed at the rear side of the first rotary bar <NUM>. The second front rotary bar <NUM> is gear-meshed with the front end of the first rotary bar <NUM>, and the second rear rotary bar <NUM> is gear-meshed with the rear end of the first rotary bar <NUM>.

The ascending/descending unit <NUM> may further include an ascending/descending housing <NUM>. The first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> are rotatably mounted in the ascending/descending housing <NUM>. The ascending/descending housing <NUM> is provided at each of the front side and the rear side thereof with a coupling portion <NUM>, which is coupled to the cleaner body <NUM>. The coupling portion <NUM> has therein a fastening hole, which penetrates the coupling portion <NUM> vertically. A bolt passes through the fastening hole, and is fastened to the cleaner body <NUM>, whereby the coupling portion <NUM> is coupled to the cleaner body <NUM>.

The ascending/descending housing <NUM> may be coupled to the cleaner body <NUM> so as to ascend or descend together with the second rotary bars <NUM> and <NUM>. That is, when the second rotary bars <NUM> and <NUM> ascend or descend, the ascending/descending housing <NUM> ascends or descends together with the second rotary bars <NUM> and <NUM>, thereby adjusting the height of the cleaner body <NUM>.

The ascending/descending drive motor <NUM> may be coupled to the outer surface of the ascending/descending housing <NUM>. The rotary shaft of the ascending/descending drive motor <NUM> may be inserted from the outside of the ascending/descending housing <NUM> into the ascending/descending housing <NUM>. A first worm <NUM>, which is coupled to the rotary shaft <NUM> of the ascending/descending drive motor <NUM>, may be disposed inside the ascending/descending housing <NUM>.

The ascending/descending drive motor <NUM> is not coupled to the center in the forward-and-backward direction of the ascending/descending housing <NUM>, but is disposed at a position biased toward one side (the rear side) in the forward-and-backward direction. The reason for this is to prevent the ascending/descending drive motor <NUM> from interfering with the travel drive motor <NUM> when the ascending/ descending unit <NUM> moves downwards. The travel drive motor <NUM> is not coupled to the center in the forward-and-backward direction of the gear housing <NUM>, but is disposed at a position biased toward the opposite side (the front side) in the forward-and-backward direction. Therefore, when the ascending/descending unit <NUM> moves downwards, the ascending/descending drive motor <NUM>, which is disposed at a position biased toward the one side in the forward-and-backward direction, is prevented from interfering with the travel drive motor <NUM>. As a result, it is possible to secure space for mounting the ascending/descending unit <NUM> in the cleaner body <NUM>.

The ascending/descending drive motor <NUM> is mounted to a portion of the outer surface of the ascending/descending housing <NUM> that faces the suspension frame <NUM>. The suspension frame <NUM> has therein an ascending/descending hole <NUM>, into which the ascending/descending drive motor <NUM> is inserted. The ascending/descending hole <NUM> is formed to have a sufficient vertical length so that the ascending/descending drive motor <NUM> ascends or descends within the ascending/descending hole <NUM> when the ascending/descending unit <NUM> ascends or descends.

The ascending/descending unit <NUM> may be mounted to the inner surface of the suspension frame <NUM>, i.e. to the surface of the suspension frame <NUM> that faces the interior of the cleaner body <NUM>, so as to be movable vertically. The suspension frame <NUM> may have stepped portions <NUM>, <NUM> and <NUM>, which are formed such that the lower portion of the inner surface of the suspension frame <NUM> protrudes further than the upper portion thereof. The stepped portions <NUM>, <NUM> and <NUM> are formed from the front end of the inner surface of the suspension frame <NUM> to the rear end thereof, and include a front stepped portion <NUM>, which is located at the front side, a rear stepped portion <NUM>, which is located at the rear side, and a middle stepped portion <NUM>, which interconnects the front stepped portion <NUM> and the rear stepped portion <NUM>. The front stepped portion <NUM> and the rear stepped portion <NUM> may be formed to have the same height, which may be greater than the height of the middle stepped portion <NUM>. The ascending/descending hole <NUM> may be formed from the upper portion of the suspension frame <NUM> to the middle stepped portion <NUM>. The ascending/descending unit <NUM> may be mounted to the front stepped portion <NUM> and the rear stepped portion <NUM> so as to be movable vertically. When the ascending/descending housing <NUM> of the ascending/descending unit <NUM> descends, it may be seated on the front stepped portion <NUM> and the rear stepped portion <NUM>. When the ascending/descending housing <NUM> descends and is seated on the front stepped portion <NUM> and the rear stepped portion <NUM>, it surrounds both sides of the protruding lower portion of the suspension frame <NUM>. Therefore, the ascending/descending housing <NUM> of the ascending/descending unit <NUM> may overlap the suspension frame <NUM>. In addition, when the ascending/descending unit <NUM> is mounted to the suspension unit <NUM>, the overall widths of the ascending/descending unit <NUM> and the suspension unit <NUM> are decreased, thereby securing space for disposing the ascending/descending unit <NUM> in the cleaner body <NUM>.

The entire portion of the first rotary bar <NUM> is accommodated in the ascending/descending housing <NUM>. However, only portions of the second rotary bars <NUM> and <NUM> are accommodated in the ascending/descending housing <NUM>. One end portions of the second rotary bars <NUM> and <NUM> protrude from the inside of the ascending/descending housing <NUM> to the outside of the ascending/descending housing <NUM>, and are mounted via insertion into the suspension unit <NUM>. The lower end portions of the second rotary bars <NUM> and <NUM> protrude from the inside of the ascending/descending housing <NUM> to the lower outside of the ascending/descending housing <NUM>, and are mounted via insertion from the top surfaces of the stepped portions <NUM>, <NUM> and <NUM> of the suspension frame <NUM> into the stepped portions <NUM>, <NUM> and <NUM>. The portion of the ascending/descending housing <NUM>, through which the second rotary bars <NUM> and <NUM> protrude to the outside of the ascending/descending housing <NUM>, may be seated on the stepped portions <NUM>, <NUM> and <NUM> when the ascending/descending unit <NUM> descends. The portion of the ascending/descending housing <NUM>, through which the second rotary bars <NUM> and <NUM> protrude to the outside of the ascending/descending housing <NUM>, may be seated on the front stepped portion <NUM> and the rear stepped portion <NUM> when the ascending/descending unit <NUM> descends.

The suspension unit <NUM> has therein insertion holes <NUM>, into which the one end portions of the second rotary bars <NUM> and <NUM> are mounted via insertion. The insertion holes <NUM> may be formed in the stepped portions <NUM>, <NUM> and <NUM> of the suspension frame <NUM>. The insertion holes <NUM> may be formed in the front stepped portion <NUM> and the rear stepped portion <NUM> of the suspension frame <NUM>. Insulators <NUM>, in which the insertion holes <NUM> are formed, may be coupled via insertion into the stepped portions <NUM> and <NUM> of the suspension frame <NUM>. The insertion holes <NUM> have threads (not illustrated) formed in the inner circumferential surfaces thereof, and the second rotary bars <NUM> and <NUM> have threads <NUM> and <NUM> formed in the outer circumferential surfaces of the one end portions thereof that protrude to the outside of the ascending/ descending housing <NUM> so as to mesh with the threads formed in the inner circumferential surfaces of the insertion holes <NUM>. Therefore, when the second rotary bars <NUM> and <NUM> rotate in one direction, the second rotary bars <NUM> and <NUM> protrude from the stepped portions <NUM> and <NUM>, and consequently the ascending/descending unit <NUM> ascends. Conversely, when the second rotary bars <NUM> and <NUM> rotate in the opposite direction, the second rotary bars <NUM> and <NUM> are inserted into the stepped portions <NUM> and <NUM>, and consequently the ascending/descending unit <NUM> descends. The suspension frame <NUM> is formed of a plastic material, whereas the second rotary bars <NUM> and <NUM> are formed of stainless steel. Therefore, in order to allow the suspension frame <NUM> to be moved vertically without being worn by the threads <NUM> and <NUM> when the second rotary bars <NUM> and <NUM> rotate, the insulators <NUM> are formed of the same material as the second rotary bars <NUM> and <NUM>, i.e. stainless steel.

The ascending/descending unit <NUM> may further include a first worm <NUM>, a first worm wheel <NUM>, second worms <NUM> and <NUM>, and second worm wheels <NUM> and <NUM>.

The first worm <NUM> may be disposed at the rotary shaft of the ascending/descending drive motor <NUM>, and may be located inside the ascending/descending housing <NUM>.

The first worm wheel <NUM> may be disposed at the first rotary bar <NUM>, and may be located inside the ascending/descending housing <NUM>. Because the ascending/descending drive motor <NUM> is coupled to the ascending/descending housing <NUM> at a position biased toward the one side in the forward-and-backward direction, the first worm wheel <NUM> is not disposed at the center in the longitudinal direction of the first rotary bar <NUM>, but is disposed at a position biased toward the one side in the same manner as the ascending/descending drive motor <NUM>. The first worm wheel <NUM> may be tooth-engaged with the first worm <NUM>. Since the first worm <NUM> and the first worm wheel <NUM> are tooth-engaged with each other, when the rotary shaft of the ascending/ descending drive motor <NUM> rotates, the first rotary bar <NUM> may be rotated together with the rotary shaft of the ascending/descending drive motor <NUM>.

The second worms <NUM> and <NUM> are disposed at the first rotary bar <NUM>, and are located inside the ascending/descending housing <NUM>. When the first rotary bar <NUM> is rotated, the second worms <NUM> and <NUM> are rotated together with the first rotary bar <NUM>. Because the second rotary bars <NUM> and <NUM> include two rotary bars, namely, the second front rotary bar <NUM> and the second rear rotary bar <NUM>, the second worms <NUM> and <NUM> include two worms, each of which is disposed at a respective one of the two end portions of the first rotary bar <NUM>. That is, the second worms <NUM> and <NUM> include a second front worm <NUM>, which is disposed at the front end portion of the first rotary bar <NUM>, and a second rear worm <NUM>, which is disposed at the rear end portion of the first rotary bar <NUM>.

The second worm wheels <NUM> and <NUM> are disposed at the second rotary bars <NUM> and <NUM>, and are located inside the ascending/descending housing <NUM>. Because the lower end portions of the second rotary bars <NUM> and <NUM> protrude to the lower outside of the ascending/descending housing <NUM> and are mounted via insertion into the insertion holes <NUM> in the suspension frame <NUM>, the second worm wheels <NUM> and <NUM> are disposed at the upper end portions of the second rotary bars <NUM> and <NUM>. The second worm wheels <NUM> and <NUM> are tooth-engaged with the second worms <NUM> and <NUM>. The second worm wheels <NUM> and <NUM> include a second front worm wheel <NUM>, which is disposed at the second front rotary bar <NUM>, and a second rear worm wheel <NUM>, which is disposed at the second rear rotary bar <NUM>. The second front worm wheel <NUM> is tooth-engaged with the second front worm <NUM>, and the second rear worm wheel <NUM> is tooth-engaged with the second rear worm <NUM>. Since the second worms <NUM> and <NUM> and the second worm wheels <NUM> and <NUM> are tooth-engaged with each other, when the first rotary bar <NUM> is rotated, the second rotary bars <NUM> and <NUM> are rotated together with the first rotary bar <NUM>. That is, when the rotary shaft of the ascending/descending drive motor <NUM> rotates, the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> are rotated together with the rotary shaft of the ascending/descending drive motor <NUM>. When the rotary shaft of the ascending/descending drive motor <NUM> rotates in one direction, the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> are rotated in the one direction. When the rotary shaft of the ascending/descending drive motor <NUM> rotates in the opposite direction, the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> are rotated in the opposite direction.

The first worm wheel <NUM>, the second worms <NUM> and <NUM> and the first rotary bar <NUM> are not formed separately from each other. The first worm wheel <NUM> and the second worms <NUM> and <NUM> may be formed integrally with the first rotary bar <NUM>. At this time, the first worm wheel <NUM>, the second worms <NUM> and <NUM> and the first rotary bar <NUM> may be integrally formed of stainless steel. Alternatively, the first worm wheel <NUM> and the second worms <NUM> and <NUM> may be formed separately from the first rotary bar <NUM>, and may be coupled to the first rotary bar <NUM>. In other words, the first worm wheel <NUM> and the second worms <NUM> and <NUM> may be formed integrally with the first rotary bar <NUM>, or may be formed separately from the first rotary bar <NUM>. Therefore, the term "disposed" was used above to describe the relationship of the first worm wheel <NUM> and the second worms <NUM> and <NUM> with respect to the first rotary bar <NUM>.

The second worm wheels <NUM> and <NUM> and the second rotary bars <NUM> and <NUM> are not formed separately from each other. The second worm wheels <NUM> and <NUM> may be formed integrally with the second rotary bars <NUM> and <NUM>. The threads <NUM> and <NUM>, which are formed in the lower end portions of the second rotary bars <NUM> and <NUM>, may also be formed integrally with the second rotary bars <NUM> and <NUM>. The second front worm wheel <NUM>, the threads <NUM> and the second front rotary bar <NUM> may be integrally formed of stainless steel. The second rear worm wheel <NUM>, the threads <NUM> and the second rear rotary bar <NUM> may be integrally formed of stainless steel. Alternatively, the second worm wheels <NUM> and <NUM> and the threads <NUM> and <NUM> may be formed separately from the second rotary bars <NUM> and <NUM>, and may be coupled to the second rotary bars <NUM> and <NUM>. In other words, the second worm wheels <NUM> and <NUM> and the threads <NUM> and <NUM> may be formed integrally with the second rotary bars <NUM> and <NUM>, or may be formed separately from the second rotary bars <NUM> and <NUM>. Therefore, the term "disposed" was used above to describe the relationship of the second worm wheels <NUM> and <NUM> with respect to the second rotary bars <NUM> and <NUM>.

The ascending/descending unit <NUM> may further include a plurality of bearings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>, which allow the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> to be rotatably coupled to the ascending/descending housing <NUM>. The bearings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> are coupled to the heaviest portion of each of the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM> in order to ensure smooth rotation of the first rotary bar <NUM> and the second rotary bars <NUM> and <NUM>. Therefore, the bearings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> may be coupled to portions of the first rotary bar <NUM> that are adjacent to the first worm wheel <NUM> and the second worms <NUM> and <NUM> and to portions of the second rotary bars <NUM> and <NUM> that are adjacent to the second worm wheels <NUM> and <NUM>.

The bearings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> include a first bearing <NUM>, which is coupled to a portion of the first rotary bar <NUM> that is adjacent to the front end of the first worm wheel <NUM>, a second bearing <NUM>, which is coupled to a portion of the first rotary bar <NUM> that is adjacent to the rear end of the first worm wheel <NUM>, a third bearing <NUM>, which is coupled to a portion of the first rotary bar <NUM> that is adjacent to the rear end of the second front worm <NUM>, a fourth bearing <NUM>, which is coupled to a portion of the first rotary bar <NUM> that is adjacent to the front end of the second rear worm <NUM>, a fifth bearing <NUM>, which is coupled to a portion of the second front rotary bar <NUM> that is adjacent to the upper end of the second front worm wheel <NUM>, a sixth bearing <NUM>, which is coupled to a portion of the second front rotary bar <NUM> that is adjacent to the lower end of the second front worm wheel <NUM>, a seventh bearing <NUM>, which is coupled to a portion of the second rear rotary bar <NUM> that is adjacent to the upper end of the second rear worm wheel <NUM>, and an eighth bearing <NUM>, which is coupled to a portion of the second rear rotary bar <NUM> that is adjacent to the lower end of the second rear worm wheel <NUM>.

<FIG> is a view illustrating the state in which the cleaner according to the embodiment of the present invention is docked with an external docking device, and <FIG> is a control block diagram of the cleaner according to the embodiment of the present invention.

Referring to <FIG> and <FIG>, the cleaner <NUM> according to the embodiment of the present invention includes a battery <NUM>, which is provided inside the cleaner body <NUM>. The battery <NUM> stores electrical energy for driving various electrical components provided at the cleaner body <NUM>. A charging terminal <NUM> for charging the battery <NUM> is disposed on the bottom surface of the cleaner body <NUM>. The charging terminal <NUM> may have a predetermined configuration enabling connection to an external docking device <NUM> for charging. The charging terminal <NUM> may be connected to a supply terminal <NUM> provided at the external docking device <NUM> in order to charge the battery <NUM>. The docking device <NUM> may be a charging stand. When the state of charge of the battery <NUM> drops below a predetermined level, the cleaner <NUM> may travel autonomously to the docking device <NUM>, and the cleaner body <NUM> may be docked with the docking device <NUM>. When the cleaner <NUM> finishes the cleaning operation, the cleaner <NUM> may travel autonomously to the docking device <NUM>, and the cleaner body <NUM> may be docked with the docking device <NUM>.

The sensing unit <NUM> may include at least one of an obstacle sensor, a floor sensor, or a position sensor. The controller <NUM> may perform control in response to the sensed values transmitted from the sensing unit <NUM> so that the ascending/descending unit <NUM> ascends or descends.

For example, the controller <NUM> may receive information related to the location of the docking device <NUM> from the sensing unit <NUM> in order to verify the location of the docking device <NUM>. Due to the configuration in which the charging terminal <NUM> is disposed on the bottom surface of the cleaner body <NUM>, when the cleaner body <NUM> intends to be docked with the docking device <NUM>, the controller <NUM> performs control such that the ascending/descending drive motor <NUM> is rotated in one direction and the ascending/descending unit <NUM> ascends, whereby the cleaner body <NUM> is moved upwards. After the ascending/descending unit <NUM> ascends, the controller <NUM> performs control such that the ascending/descending drive motor <NUM> is rotated in the opposite direction and the ascending/descending unit <NUM> descends, whereby the cleaner body <NUM> is moved downwards and the charging terminal <NUM> is connected to the supply terminal <NUM> of the docking device <NUM>.

The cleaning nozzle <NUM> includes a suction port, which is formed at the bottom surface of the cleaning nozzle <NUM> in order to suck foreign substances from an area to be cleaned. For example, when the cleaner <NUM> travels on a carpet laid over a floor, fibers of the carpet may be drawn into the suction port by the suction force of the cleaning nozzle <NUM>, and this suction force applied between the carpet and the suction port may degrade the traveling performance of the cleaner. Therefore, the cleaner <NUM> according to the embodiment of the present invention is capable of moving the ascending/descending unit <NUM> upwards or downwards by controlling the ascending/ descending drive motor <NUM> depending on the material of the area to be cleaned, thereby adjusting the height of the cleaning nozzle <NUM>. The sensing unit <NUM> may acquire information related to the material of the area to be cleaned, and the controller <NUM> may receive the information about the area to be cleaned from the sensing unit <NUM>. The sensing unit <NUM> may be at least one of a distance sensor, a reflectance measuring sensor, or an image sensor, which acquires information related to the material of the area to be cleaned. Upon determining that the area to be cleaned is a carpet based on the information about the area to be cleaned transmitted from the sensing unit <NUM>, the controller <NUM> performs control such that the ascending/descending drive motor <NUM> is rotated in one direction and the ascending/descending unit <NUM> ascends, whereby the cleaning nozzle <NUM> is moved upwards. Upon determining that the cleaner body <NUM> has left the carpet based on the information about the area to be cleaned, the controller <NUM> performs control such that the ascending/descending drive motor <NUM> is rotated in the opposite direction and the ascending/descending unit <NUM> descends, whereby the cleaning nozzle <NUM> is moved downwards.

As described above, the cleaner according to the embodiment of the present invention is configured such that the ascending/descending unit <NUM> for moving the cleaner body <NUM> upwards or downwards is mounted to the suspension unit <NUM>. Therefore, even when the height of the cleaner body <NUM> is adjusted by the ascending/ descending unit <NUM>, the suspension unit <NUM> is capable of continuously absorbing shocks applied to the wheel unit <NUM>.

In addition, the suspension frame <NUM> of the suspension unit <NUM> includes the stepped portions <NUM>, <NUM> and <NUM>, on which the ascending/descending housing <NUM> of the ascending/descending unit <NUM> is seated when the ascending/descending unit <NUM> descends. Therefore, when the ascending/descending unit <NUM> is mounted to the suspension unit <NUM>, the overall widths of the ascending/descending unit <NUM> and the suspension unit <NUM> are decreased, thereby securing space for disposing the ascending/ descending unit <NUM> in the cleaner body <NUM>.

As is apparent from the above description, the present invention provides a cleaner in which an ascending/descending unit for moving a cleaner body upwards or downwards is mounted to a suspension unit. Therefore, even when the height of the cleaner body is adjusted by the ascending/descending unit, the suspension unit is capable of continuously absorbing shocks applied to a wheel unit.

In addition, when a cleaning nozzle sucks foreign substances from a carpet, the height of the cleaning nozzle is increased, thereby preventing fibers of the carpet from being drawn into a suction port formed at the bottom surface of the cleaning nozzle and consequently preventing degradation of the traveling performance of the cleaner body.

In addition, when the cleaner intends to be docked with an external docking device in order to charge a battery, the cleaner body is moved upwards so that a charging terminal provided at the bottom surface of the cleaner body is located at a position enabling connection to the docking device.

In addition, a suspension frame of the suspension unit includes stepped portions, on which an ascending/descending housing of the ascending/descending unit is seated when the ascending/descending unit descends. Therefore, when the ascending/descending unit is mounted to the suspension unit, the overall widths of the ascending/descending unit and the suspension unit are decreased, thereby securing space for disposing the ascending/descending unit in the cleaner body.

Claim 1:
A cleaner comprising:
a cleaner body (<NUM>);
a wheel unit (<NUM>) comprising a wheel configured to support the cleaner body (<NUM>) so that the cleaner body (<NUM>) travels on an area to be cleaned;
a suspension unit (<NUM>), to which the wheel unit (<NUM>) is mounted so as to be movable vertically, the suspension unit (<NUM>) being configured to absorb shocks when the wheel unit (<NUM>) moves vertically; and
an ascending/descending unit (<NUM>) mounted to the suspension unit (<NUM>) so as to be ascendable and descendable and coupled to the cleaner body (<NUM>) so as to ascend or descend together with the cleaner body (<NUM>),
characterized in that:
the ascending/descending unit (<NUM>) comprises:
an ascending/descending drive motor (<NUM>);
a first rotary bar (<NUM>) configured to be rotated by torque of the ascending/descending drive motor (<NUM>); and
at least one second rotary bar (<NUM>, <NUM>) arranged perpendicular to the first rotary bar (<NUM>) so as to be rotated by rotational force of the first rotary bar (<NUM>), the second rotary bar (<NUM>, <NUM>) being mounted to the suspension unit (<NUM>) so that the cleaner body (<NUM>) ascends or descends along with rotation of the second rotary bar (<NUM>, <NUM>).