SENSOR ASSEMBLY AND ROBOT CLEANER HAVING THE SAME

Disclosed herein are a sensor assembly executing functions of both an obstacle sensor and a vision sensor and a robot cleaner having the same. The robot cleaner includes a main body and at least one sensor assembly mounted on the main body, the sensor assembly includes a housing, a light emitting module mounted on the housing and generating a light beam, and a light receiving module mounted on the housing and receiving reflected light obtained by reflecting the light beam generated from the light emitting module by an obstacle, the light receiving module includes a receiving reflector concentrating the reflected light and provided with the opened central part to form a vision hole and a camera unit sensing light, and the camera unit senses the reflected light concentrated by the receiving reflector and photographs an image above the main body through the vision hole, simultaneously.

DETAILED DESCRIPTION

Hereinafter, a sensor assembly and a robot cleaner having the same in accordance each embodiment will be described with reference to the accompanying drawings.

FIG. 1is a perspective view illustrating a robot cleaner in accordance with one embodiment, andFIG. 2is a view illustrating the configuration of the robot cleaner in accordance with the embodiment. With reference toFIG. 1, F denotes a forward moving direction, and R denoted a rearward moving direction. Based on these directions, the forward moving direction is defined as the forward direction, and the rearward moving direction is defined as the rearward direction.

As shown inFIGS. 1 and 2, a robot cleaner1may include a main body10forming the external appearance of the robot cleaner1, a cover20covering the upper portion of the main body10, and a main brush30sweeping up dust present in a space to be cleaned or dispersing the dust.

The main body10may have various shapes. For example, the main body10may be formed in a circular shape. If the circular main body10is rotated, the rotating radius of the main body10is constant and thus the main body10may avoid contact with a peripheral obstacle and easily change direction. Further, the circular main body10may prevent the main body10from being caught on an obstacle during traveling.

Two driving wheels90may be symmetrically arranged at the left and right edges of the central region of the lower portion of the main body10. The two driving wheels90allow the robot cleaner1to execute motions, such as forward movement, rearward movement and rotation, during cleaning. For example, the left and right driving wheels90may be identically controlled so that the robot cleaner1may travel in the forward or rearward direction. Otherwise, the left and right driving wheels90may be differently controlled so that the robot cleaner1may change direction.

A caster (not shown) may be installed at the front edge of the lower portion of the main body10. The caster (not shown) may allow the robot cleaner1to maintain the stable pose. The driving wheels90and the caster (not shown) may be formed in one assembly which is detachably mounted on the lower portion of the main body10.

A power supply unit80to drive the main body10and various constituent parts mounted on the main body10may be arranged within the main body10. The power supply unit80may include a battery electrically connected to respective drive devices and supplying drive power. As the battery, a rechargeable secondary battery is used, and such a secondary battery is charged with power supplied from a docking station (not shown) if the main body10having completed the cleaning process is connected to the docking station (not shown).

The main brush30may be mounted at a position slightly to the rear of the central region of the lower portion of the main body10. The main brush30removes dust accumulated on the floor on which the main body10is placed. The main brush30agitates dust accommodated on the floor and guides the dust to a dust inlet (not shown). An air blower device (not shown) is provided within the dust inlet (not shown), and thus moves the dust introduced into the dust inlet (not shown) to a dust collector70.

Side brushes40to clean areas at the side of the main body10or corner areas may be mounted on the main body10. Each of the side brushes40may be rotatably mounted at one side of the edge of the lower surface of the main body10. The side brushes40may be mounted at positions located diagonally from the central region of the main body10to the front portion of the main body10.

The side brushes40may move dust accumulated around the main body10to the main brush30. The side brushes40may extend the cleaning range of the robot cleaner1to the periphery of the floor under the main body10.

A display unit25to display various pieces of information, such as the operating state of the robot cleaner1, the amount of dust, the charge amount of the battery, time, etc., may be formed at the central region of the cover20.

A sensor assembly100may be mounted on the front portion of the main body10. A sensor window50may be formed on the front surface of the main body10so that the light beam generated from the sensor assembly100is transmitted by the sensor window50and light reflected by an obstacle or a wall surface is introduced into the sensor window50.

The sensor window50may be formed of a material which may transmit light generated from the sensor assembly100. A film transmitting light of only a specific range which the sensor assembly100may sense may be adhered to the sensor window50. For example, if the sensor assembly100emits infrared light and senses light reflected by an obstacle and a wall surface among the infrared light, an infrared filter transmitting only infrared light may be adhered to the sensor window50.

A vision window60may be formed on the main body10above the sensor assembly100so as to allow the sensor assembly100to photograph an upper image perpendicular to the traveling direction of the robot cleaner1. The vision window60may be formed of a transparent material so as to allow the sensor assembly100to effectively photograph the upper image. Since the visible light passes through the image, the vision window60may be completely transparent so as to transmit visible light.

A lens may be mounted at the center of the vision window60, and a description thereof will be given later.

FIG. 3is a perspective view illustrating the sensor assembly in accordance with the embodiment.

As shown inFIG. 3, the sensor assembly100may include a light emitting module200and a light receiving module300.

A housing110may form the external appearance of the sensor assembly100. The light emitting module200and the light receiving module300may be mounted on the housing110. The light emitting module200and the light receiving module300mounted on the housing110may form one sensor assembly100.

Although this embodiment illustrates the light emitting module200and the light receiving module300as forming one sensor assembly100, the light emitting module200and the light receiving module300are separately mounted.

A support part120may be provided on the front surface of the bottom of the housing110, and the light emitting module200is mounted on the support part120.

A camera unit310of the receiving module300may be arranged in the rear of the light emitting module200.

A receiving reflector320may be mounted on a column part bent upward from the bottom of the housing110. The receiving reflector320may be mounted on the housing110so as to be located perpendicularly above the camera unit310.

The light emitting module200may include a light emitting unit210and an emitting reflector220. The light emitting unit210and the emitting reflector220may be mounted a light emitting module case230and form one light emitting module200.

The light emitting unit210corresponds to a light source generating light and irradiating the light, and may employ a laser diode (LD) or an LED. The kind of the light emitting unit210is not limited but, hereinafter, a light emitting unit210employing an LD will be exemplarily described.

A laser generated from the light emitting unit210may be in an infrared light region or a visible light region. Hereinafter, a laser in the infrared light region irradiated from the light emitting unit210will be exemplarily described.

The emitting reflector220may be formed in a conical shape. The emitting reflector220is mounted on the light emitting module case230such that the apex (vertex) of the emitting reflector220faces the light emitting unit210. The emitting reflector220may be arranged such that the apex of the emitting reflector220is located perpendicularly above the center of the light emitting unit210.

The light receiving module300may include the receiving reflector320and the camera unit310. The light beam generated from the light emitting module200is reflected by an obstacle or a wall surface and thus forms reflected light, and such reflected light is concentrated by the receiving reflector320. The receiving reflector320reflects the reflected light toward the camera unit310. The camera unit310senses the reflected light reflected by the receiving reflector320.

The receiving reflector320is formed in an almost conical shape such that the apex part of the receiving reflector320is opened to form a vision hole330. The vision hole330allows the camera unit310to photograph an image perpendicularly above the robot cleaner1through the vision window60.

In order to mount the receiving reflector320on the housing110, a part of the receiving reflector320mounted on the housing110may be flat. If the receiving reflector320may be mounted on the housing110using a separate mounting unit, the receiving reflector320may be formed in a completely conical shape.

FIG. 4is a view illustrating a light beam generated from the light emitting module of the sensor assembly ofFIG. 3.

As shown inFIGS. 3 and 4, the light emitting unit210irradiates infrared light toward the emitting reflector220. The infrared light irradiated to the emitting reflector220is reflected by the emitting reflector220, thus directing the light beam in all directions of 360 degrees.

AlthoughFIG. 4illustrates that infrared light is reflected only in the leftward and rightward directions of the emitting reflector220, infrared light is reflected in all directions of 360 degrees along the circumference of the conical emitting reflector220.

FIG. 5is a view illustrating a region of the light beam emitted from the robot cleaner in accordance with the embodiment.

As shown inFIGS. 3 and 5, a region A11of the light beam emitting from the robot cleaner1is not formed in a completely circular shape, and is formed in a fan shape.

Although the emitting reflector220emits infrared light in all direction of 360 degrees, the regions A11of the light beam is formed in a fan shape, not in a circular shape, due to various constituent parts within the light emitting module case230and the main body10.

The infrared light is emitted through the sensor window50(with reference toFIG. 1) of the robot cleaner1.

FIG. 6is a plan view of the receiving reflector of the sensor assembly ofFIG. 3.

As shown inFIG. 6, the central part of the receiving reflector320may be opened to form the vision hole330.

The vision window60(with reference toFIG. 1) is arranged perpendicularly above the vision hole330. The camera unit310photographs an image perpendicularly above the robot cleaner1through the vision hole330and the vision window60.

The size of the vision hole330may be structurally insufficient to photograph an image above the robot cleaner1. If the vision hole330has an insufficient size, a wide-angle lens350may be mounted on the upper portion of the receiving reflector320.

The wide-angle lens350has a short focal length, and provides a wide viewing angle, as compared with a standard lens. Therefore, although the vision hole330has an insufficient size, the wide-angle lens350allows the camera unit310to photograph an image of a wide area above the robot cleaner1.

The wide-angle lens350may be mounted on the housing110so as to be arranged on the upper portion of the receiving reflector320. That is, the sensor assembly100may include the wide-angle lens350.

Otherwise, a wide-angle lens350may be mounted at the central part of the vision window60(with reference toFIG. 1). Since the vision window60is arranged perpendicularly above the receiving reflector320, if the wide-angle lens350is mounted on the vision window60, the camera unit310may photograph an image of a sufficiently wide area above the robot cleaner1.

The camera unit310senses a singular point provided on the ceiling by photographing the image above the robot cleaner1. The singular point is a generic name of objects fixed to the ceiling, such as a fluorescent lamp, a column, a corner, etc.

The camera unit310may judge whether or not the robot cleaner1travels in the correct direction by sensing the singular point. As one example, if the robot cleaner1travels in parallel with a fluorescent lamp on the ceiling, when the robot cleaner1slips or moves due to an inclined floor surface or external force, the traveling direction of the robot cleaner1may be changed. In this case, when the robot cleaner1continuously travels, the robot cleaner1travels in a direction differing from the direction of the fluorescent lamp which has been originally recognized, and then relative movement of the fluorescent lamp sensed by the camera unit310may be changed. When the relative movement of the singular point, i.e., the fluorescent lamp, is changed, it is judged that the robot cleaner1travels in a direction differing from a desired direction, and thus the traveling direction of the robot cleaner1may be adjusted to the desired direction.

The traveling direction of the robot cleaner1may be correctly maintained by sensing the singular point above the robot cleaner1in such a manner.

As another example, if the robot cleaner1travels along a predetermined path, i.e., in case of a cleaning system requiring a map, a camera module to receive position information of the robot cleaner1and to create a map may be used.

In addition, the camera unit310may photograph an image above the robot cleaner1and use the image in various ways.

FIG. 7is a view schematically illustrating the configuration and operation of the sensor assembly of the robot cleaner in accordance with the embodiment.

FIG. 7illustrates the light emitting unit210, the emitting reflector220, the receiving reflector320and the camera unit310among the constituent parts of the sensor assembly100mounted on the front surface of the robot cleaner1.

In order to illustrate the operation of the robot cleaner1, arrangement of two obstacles L1and L2in front of the robot cleaner1will be exemplarily described. It is assumed that the first obstacle L1and the second obstacle L2are not arranged on the same line but, rather, are arranged on different lines.

The light emitting unit210irradiates infrared light toward the emitting reflector220. The infrared light irradiated to the emitting reflector220is reflected in all directions of 360 degrees by the emitting reflector220, thus directing the light beam in all directions.

The light beam is reflected by the first obstacle L1and the second obstacle L2, and is concentrated by the receiving reflector320.

The camera unit310photographs an image using the reflected light concentrated by the receiving reflector320.

FIG. 8is a view illustrating an image recognized by the camera unit of the sensor assembly in accordance with the embodiment.

As shown inFIGS. 7 and 8, the image recognized by the camera unit310is divided into an obstacle sensing area SA representing concentration of infrared light reflected by the obstacles into the receiving reflector320, and a vision image area VA representing an image photographed through the vision hole330.

Since the vision hole330is formed at the central part of the receiving reflector320, the vision image area VA is formed at the center of the image recognized by the camera unit310.

The vision image area VA is a part corresponding to a distance L0from the sensor assembly100to the front surface of the robot cleaner1, and thus does not represent the obstacles even if infrared light is reflected and concentrated. Therefore, although such an area represents the image photographed by the camera unit310, sensing of an obstacle or a wall surface is not influenced thereby.

In the vision image area VA, the image above the robot cleaner1is directly displayed.

The image recognized by the camera unit310represents infrared light reflected by the obstacles L1and L2among light beam, and may thus be shown by lines.

In such an image, two lines representing infrared light reflected by the obstacles L1and L2are formed. Since the first obstacle L1and the second obstacle L2are not arranged on the same line, the two lines are formed in different directions.

Among the two lines, the line formed at left represents infrared light reflected by the first obstacle L1, and the line formed at right represents infrared light reflected by the second obstacle L2.

Since a distance L11to the first obstacle L1is shorter than a distance L12to the second obstacle L2, the left line is closer to the center than the right line.

Infrared light formed in the obstacle sensing area SA may be expressed through x and y coordinates, and this may correspond to correct absolute positions of the obstacles.

In terms of distance, the actual distance L11from the robot cleaner1to the first obstacle L1and the distance L12from the center of the image to the left infrared line have the corresponding value. The actual distance L11to the first obstacle L1may be calculated by analyzing the distance L12through a controller (not shown).

In such a manner, the directions in which the obstacles L1and L2are located may be calculated.

FIG. 9is a view illustrating the configuration of a robot cleaner in accordance with one embodiment.

As shown inFIG. 9, a robot cleaner2in accordance with this embodiment may include a main body10, and a cover21covering the upper portion of the main body10.

Two driving wheels90may be symmetrically arranged at the left and right edges of the central region of the lower portion of the main body10.

A sensor assembly100may be mounted at the central part of the main body10. If the sensor assembly100is mounted at the central part of the main body10, infrared light is not emitted in all directions by various constituent parts arranged within the main body10. Therefore, the sensor assembly100may be mounted at a higher position than other constituent parts.

FIG. 10is a side view of the robot cleaner ofFIG. 9.

As shown inFIGS. 9 and 10, since the sensor assembly100is located at a higher position than the side surface of the main body10, the cover21installed on the upper portion of the main body10may be provided with an inclined surface such that the central part of the cover21is gently protruded so as to accommodate the sensor assembly100.

According to the size of the sensor assembly100, a protrusion having a size corresponding to the size of the sensor assembly100may be formed at the central part of the cover21.

A vision window61may be formed at the central part of the cover21so as to allow a camera unit310(with reference toFIG. 3) of the sensor assembly100to photograph an image above the robot cleaner2.

FIG. 11is a view illustrating a region of the light beam emitted from the robot cleaner ofFIG. 9.

As shown inFIG. 11, since the sensor assembly100is located at a higher position than the main body10, infrared light irradiated from the sensor assembly100is not shielded by other constituent parts.

Therefore, a region A21of the light beam emitting from the robot cleaner2may be formed in a completely circular shape.

FIG. 12is a view illustrating the configuration of a robot cleaner in accordance with one embodiment, andFIG. 13is a view illustrating a region of the light beam emitted from the robot cleaner ofFIG. 12.

As shown inFIGS. 12 and 13, a robot cleaner3in accordance with this embodiment may include a pair of vision windows62aand62blocated so as to be biased in the diagonal direction on the front portion of a main body10.

Two sensor assemblies100(with reference toFIG. 3), each of which is installed below each of the vision windows62aand62b, may be installed.

If one pair of vision windows62aand62band one pair of the sensor assemblies100are installed, a region of the light beam generated from the robot cleaner3may be increased.

When the robot cleaner3actually travels, portions of the robot cleaner3biased in the diagonal direction on the front portion of the robot cleaner3rather than the front surface of the robot cleaner3may easily collide with an obstacle or a wall surface. Therefore, by arranging the vision windows62aand62band the sensor assemblies100, as shown inFIGS. 12 and 13, whether or not the portions of the robot cleaner3easily generating collision approach an obstacle or a wall surface may be sensed.

FIG. 14is a view illustrating the configuration of a robot cleaner in accordance with a one embodiment, andFIG. 15is a view illustrating a region of the light beam emitted from the robot cleaner ofFIG. 14.

As shown inFIGS. 14 and 15, a robot cleaner4in accordance with this embodiment may include two vision windows63aand63bformed at the front portion and the rear portion of a main body10.

Two sensor assemblies100(with reference toFIG. 3), each of which is installed below each of the vision windows63aand63b, are installed.

If the two vision windows63aand63band the two sensor assemblies100are provided at the front portion and the rear portion of the robot cleaner4, a region of the light beam generated from the robot cleaner3may be extended to the rear area A42in addition to the front area A41.

When the region A41, A42, A43and A44of the light beam is extended to the rear area, collision of the robot cleaner4with an obstacle or a wall surface arranged in an area in the rear of the robot cleaner4may be prevented even if the robot cleaner4moves rearward.

Although the above embodiments of the present invention describe various mounting methods of the sensor assemblies100, the sensor assemblies100may be mounted at various portions of the robot cleaner in addition to the described mounting methods. For example, the sensor assemblies100may be installed at all of the front, rear and side portions of the robot cleaner.

Further, although the above embodiments describe installation of one or two sensor assemblies100, a larger number of sensor assemblies100may be installed.

FIGS. 16A and 16Bare views illustrating some constituent parts of a sensor assembly in accordance with one embodiment.

As shown inFIGS. 16A and 16B, a slit114provided with a groove having a designated shape formed thereon may be arranged between a laser diode112and a conical emitting reflector111. The slit114changes the shape of a laser beam irradiated from the laser diode112into one of various shapes according to the shape of the groove, and then allows the laser beam having the changed shape to be incident upon the emitting reflector111.

If a cross-shaped groove is formed on the slit114, as shown inFIG. 16A, the slit114changes the shape of the laser beam irradiated from the laser diode112into a cross shape. The cross-shaped laser beam is incident upon the emitting reflector111and thus generates omnidirectional light beam in which the intensity of light directed in specific directions is higher than the intensity of light directed in other directions. In more detail, when the cross-shaped laser beam is reflected by the surface of the emitting reflector111, the intensity of light directed in the directions a, b, c and d become higher than the intensity of light directed in other directions. Here, the directions a, b, c and d are random directions which meet at right angles to each other.

In sensing of an obstacle, although generation of a uniform light beam may be advantageous, different intensities of light according to direction may be required as needed. In this case, the slit114provided with the cross-shaped groove may be used, and the number of strokes of the groove may be adjusted as needed.

As shown inFIG. 16B, if the slit114having an I-shaped groove formed thereon by removing one stroke from the cross-shaped groove is used, omnidirectional light beam in which the intensity of light directed in the directions b and d is higher than the intensity of light directed in other directions is generated.

FIG. 17is a view illustrating some constituent parts of a sensor assembly in accordance with one embodiment.

If light irradiated from a light source is incident directly upon a reflector, generated light beam has a designated thickness. According to purpose of the sensor assembly110, generation of sharp light beam may be required.

As shown inFIG. 17, when the light emitting unit112is covered with a cap-shaped structure115provided with a small hole formed on the upper portion thereof, light irradiated from the light emitting unit112passes through the hole formed on the structure115and thus the divergence angle of the light is reduced, and the light having the reduced divergence angle is incident upon the emitting reflector11and thus generates the light beam of a thin thickness.

FIGS. 18A and 18Bare views illustrating some constituent parts of a sensor assembly in accordance with one embodiment.

With reference toFIG. 18A, an emitting reflector111includes at least two conical mirror pieces having different diameters. In more detail, in the embodiment ofFIG. 18A, the emitting reflector111is formed by arranging a piece111aobtained by bisecting a conical mirror having a diameter D1in the vertical direction and a piece111bobtained by bisecting a conical mirror having a diameter D2in the vertical direction such that the cross sections of the piece111aand the piece111bare opposite each other. The right portion ofFIG. 18Aillustrates the shape of the emitting reflector111as seen from the top.

The emitting reflector111shown inFIGS. 18A and 18Bmay be applied directly to the sensor assembly, and a rotating device (not shown) may be connected to the emitting reflector111so as to rotate the emitting reflector111.

FIG. 19is a view illustrating some constituent parts of a sensor assembly in accordance with one embodiment.

With reference toFIG. 19, the sensor assembly in accordance with this embodiment may include a plurality of light beam emitting units irradiating light at different heights. In this embodiment, for example, the sensor assembly includes three light beam emitting units110ato110c. However, more or less units can be provided as needed to generate the desired coverage.

As shown inFIG. 19, if the first to third light beam emitting units110ato110care located at different heights, the first light beam emitting unit110asenses the upper portion of an obstacle and the third light beam emitting unit110csenses the lower portion of the obstacle, based on the second light beam emitting unit110b.

AlthoughFIG. 19illustrates the obstacle as having a greater height than the first light beam emitting unit110a, if the obstacle has a height smaller than the first light beam emitting unit110aand greater than the second light beam emitting unit110b, light emitted from the second and third light beam emitting units110band110cis received by a reflected light receiving unit120, and if the obstacle has a height smaller than the second light beam emitting unit110band greater than the third light beam emitting unit110c, only light emitted from the third light beam emitting unit110cis received by the reflected light receiving unit120.

In order to judge which light beam emitting unit emits light received by the reflected light receiving unit120, points of time when the respective light beam emitting units110ato110cirradiate light may be different, and if the respective light beam emitting units110ato110csimultaneously irradiate light, colors of light emitted from the respective light beam emitting units110ato110cmay be different.

Although the embodiment ofFIG. 19illustrates the light beam emitting units110a,110band110cas being aligned in a vertical line, the light beam emitting units110a,110band110cmay be independently separated.

As is apparent from the above description, in a sensor assembly and a robot cleaner having the same in accordance with one embodiment, an obstacle sensor and a vision sensor form one sensor assembly, and thus the robot cleaner may have a simple structure.

Further, the sensor assembly in accordance with the embodiment may reduce the area of a space occupied by the robot cleaner and the overall size of the robot cleaner.

Further, the robot cleaner senses obstacles present in all directions using a light beam, and does not require a plurality of sensors or a separate servo-mechanism, thus improving economical and structural efficiency.