Patent Description:
With developments in robot technology, robots are not only found in specialized academic fields or industrial fields which require mass scale labor, but they are also becoming more common in average homes. In addition, robots are not only being supplied to perform a function at a fixed position, but mobile robots are also being supplied that are capable of traveling. Among the mobile robots, two wheeled robots with two wheels have an advantage of taking up a small surface area, and two wheeled robots of various types (Segway, Ninebot, etc.) are widely utilized.

In the related art, two wheeled robots are configured such that a center of mass of the body is always above a rotational axis of a wheel relative to the surface on which the robot may travel upon, and a balancing control is carried out so as to prevent the robot from falling. The mobile robots embodying this structure have a problem in that they are susceptible to swaying according to a rotational inertial force which can make it difficult to stably travel, and this instability further prevents such robots from being able to return to their original position when having fallen. <CIT> describes an inverted moving body that has a rotary body having a cross section of a circular shape. <CIT> describes a mobile robot to travel over stepped obstacles. <CIT> describes a spherical robot with a wheel-shaped body.

Aspects of the disclosure are to address at least the above-mentioned problems and/or disadvantages, and an object of the disclosure is in providing a mobile robot apparatus which can travel stably and collect information as a body travels contacting with a surface, or travels spaced apart from the surface.

According to an embodiment, a mobile robot apparatus includes a body, a first wheel and a second wheel disposed respectively at opposite side surfaces of the body, a first drive device configured to provide driving force to each of the first and second wheels, a second drive device configured to move the body in a vertical direction based on a center axis of the first and second wheels, and a processor configured to control the second drive device for the body to move by contacting with a surface, or move spaced apart from the surface.

The first drive device may include a first motor configured to provide driving force to the first wheel, and a second motor configured to provide driving force to the second wheel.

The second drive device includes a rack disposed in at least one from among the first and second wheels, and a pinion disposed in the body to engage with the rack.

The rack may include a first rack disposed in the first wheel and a second rack disposed in the second wheel, and the pinion may include a first pinion disposed to engage with the first rack, and a second pinion disposed to engage with the second rack.

The second drive device may include a third motor configured to rotate the first pinion, and a fourth motor configured to rotate the second pinion.

The first wheel may include a rotatable first wheel cover and a first intermediate member disposed between the first wheel cover and the body, the second wheel may include a rotatable second wheel cover and a second intermediate member disposed between the second wheel cover and the body, the first rack may be disposed at the first intermediate member, and the second rack may be disposed at the second intermediate member.

The mobile robot apparatus may further include a guide rail disposed in at least one from among the first and second intermediate members, and the body may include a block which is movable along the guide rail at a side surface.

The guide rail may be vertically disposed.

The mobile robot apparatus may further include a camera disposed at the body and configured to capture a surrounding environment of the mobile robot apparatus.

The body may include a caster which is connected to a bottom surface to be rotatable.

A rotational axis of the caster may be parallel with a rotational axis of the first and second wheels.

The processor may be configured to control the second drive device for the caster to be selectively in contact with the surface or be spaced apart from the surface.

The processor may be configured to control the second drive device for the body to be tilted in a direction to which the mobile robot apparatus is turned.

The processor may be configured to control, based on the body contacting with the surface by falling, the second drive device for the first and second wheels to move toward the body until a center of mass of the body is positioned outside a section between a contact point of the body and a contact point of the first and second wheels.

Embodiments described below are provided as examples to assist in the understanding of the disclosure, and it is to be understood that the disclosure may be variously modified and realized, differently from the embodiments described herein. However, in describing the disclosure below, in case it is determined that the detailed description of related known technologies may unnecessarily confuse the gist of the disclosure, the detailed description and detailed illustration will be omitted. In addition, accompanied drawings are not shown in its actual scale but shown with scales of some elements exaggerated to assist in the understanding of the disclosure.

Terms used in the disclosure and in the claims are general terms selected considering their function herein. However, the terms may change depending on intention, legal or technical interpretation, emergence of new technologies, and the like of those skilled in the related art. Further, in certain cases, there may be terms arbitrarily selected. With respect to these terms, the meaning of the term may be interpreted as defined in the description, and if there is no specific definition of the term, the term may be interpreted based on the overall context of the disclosure and the technical common sense of the related art.

In the disclosure, expressions such as "have," "may have," "include," "may include," or the like are used to designate a presence of a corresponding characteristic (e.g., elements such as numerical value, function, operation, or component), and not to preclude a presence or a possibility of additional characteristics.

Further, elements necessary in describing each embodiment of the disclosure are described herein, but the disclosure is not necessarily limited thereto. Accordingly, some elements may be modified or omitted, and other elements may be added. In addition, the elements may be distributed and disposed in separate devices different from one another.

Furthermore, embodiments of the disclosure have been described in detail with reference to the accompanied drawings and descriptions described in the accompanied drawings below, it is to be understood that the disclosure is not limited by or limited to the embodiments.

Embodiments will be described in detail below with reference to the accompanied drawings.

<FIG> is a front perspective view of a mobile robot apparatus according to an embodiment of the disclosure. <FIG> is a rear perspective view of the mobile robot apparatus according to an embodiment of the disclosure. <FIG> is a front view of a mobile robot apparatus of which a body is in contact with a surface.

A mobile robot apparatus <NUM> may be a device with various functions such as autonomously traveling while recognizing a surrounding environment and collecting information, delivering information to a user, and the like. The mobile robot apparatus <NUM> may recognize the surrounding environment based on a voice, a sound, and an image. In addition, information may be delivered to the user by controlling other electronic products through wireless communication or outputting a voice.

The mobile robot apparatus <NUM> may collect and analyze various information such as sounds, voices, images, and the like from the surrounding environment to make stable autonomous traveling possible. For example, the mobile robot apparatus <NUM> may include a microphone, a camera, a sensor, and the like to collect information on the surrounding environment.

The mobile robot apparatus <NUM> may physically travel by including a drive member, and through the drive member, execute various functions of the mobile robot apparatus <NUM> throughout the environment of the user which may include indoors and outdoors.

If the mobile robot apparatus <NUM> is used within a home, the mobile robot apparatus may interact with the electronic products within the home, such as a television (TV), a cleaner, and a washer, to execute a function and collect information, and to deliver the collected information to family members including a pet. Accordingly, the mobile robot apparatus may connect all members within the home with the electronic products.

The mobile robot apparatus <NUM> may continuously check and inspect the environment within the home even when the user is not present and connect the user with family members including a pet that needs assistance. In addition, other electronic products within the home may be checked and operated through physical travel of the mobile robot apparatus <NUM>. Through the above, safety within the home may be sought after and security within the home may be enhanced.

The mobile robot apparatus <NUM> according to an embodiment of the disclosure may be implemented in a form related to the performance of a job within the home, but is not limited thereto, and may be implemented as a robot apparatus according to various embodiments.

Referring to <FIG>, the mobile robot apparatus <NUM> according to an embodiment of the disclosure may include a body <NUM>, a first wheel <NUM>, and a second wheel <NUM>. Covers of the body <NUM>, the first wheel <NUM>, and the second wheel <NUM> may have a same curvature, and accordingly, an exterior of the mobile robot apparatus <NUM> may be formed to realize a sphere.

Although not shown in <FIG>, a motor, a battery, an actuator, a gear, a bearing, and the like for driving the mobile robot apparatus <NUM> may be included inside of the body <NUM> of the mobile robot apparatus <NUM>.

A camera <NUM> may be provided at an outer surface <NUM> of the body <NUM> to capture the surrounding environment of the mobile robot apparatus <NUM>. In addition, a sensor <NUM> may be provided at the outer surface <NUM> of the body <NUM>. The sensor <NUM> may be at least one from among an image sensor which detects an obstacle, a sound sensor which detects a voice, a temperature sensor which detects temperature, and a humidity sensor which detects humidity.

The mobile robot apparatus <NUM> may recognize, based on information collected from the camera <NUM> and from at least one sensor <NUM> disposed at the body <NUM>, the surrounding environment, autonomously travel and collect information, and deliver information to the user.

The body <NUM> may include a caster <NUM> which is rotatably connected to a bottom surface. A rotational axis X2 of the caster <NUM> may be parallel with a center axis X1 of the first and second wheels <NUM> and <NUM>.

The caster <NUM> may be configured such that a portion is protruded to the outside than the bottom surface of the body <NUM>. The caster <NUM> may be formed of plastic or metal, may have a rotatable ball caster form and thereby, reducing frictional force with the surface.

Each of the first and second wheels <NUM> and <NUM> may be in contact with the surface from a first point S1 and a second point S2. In addition, the bottom surface of the body <NUM> excluding the caster <NUM> may be spaced apart from the surface, and the caster <NUM> may be in contact with the surface from a third point S3.

Accordingly, the mobile robot apparatus <NUM> may be supported from the first to third points S1, S2, and S3 of the surface (three-point support mode). The body <NUM> may be in contact with the surface, and the center of mass of the body <NUM> may be positioned at a lower side than the center axis X1 of the first and second wheels <NUM> and <NUM>.

When the mobile robot apparatus <NUM> completes traveling to a specific location, the center of mass of the body <NUM> may travel to a point below the center axis X1 of the first and second wheels <NUM> and <NUM>, and the mobile robot apparatus <NUM> may stop at the specific location in a stable position.

When the center of mass of the body <NUM> is at a point below the center axis X1 of the first and second wheels <NUM> and <NUM>, the mobile robot apparatus <NUM> may travel stably at a low speed without swaying. In addition, the camera <NUM> disposed on the unswaying body <NUM> may accurately capture the surrounding environment of the mobile robot apparatus <NUM>.

In addition, because there is no need for control of a second drive device <NUM> (see <FIG>) that moves the body <NUM>, which will be described below, in a vertical direction based on the center axis of the first and second wheels <NUM> and <NUM>, the mobile robot apparatus <NUM> may efficiently travel at low energy.

The first wheel <NUM> and the second wheel <NUM> may be respectively disposed at opposite side surfaces of the body <NUM>. The first and second wheels <NUM> and <NUM> may respectively be provided with driving force from a first drive device <NUM> (<FIG>) and rotate about the center axis X1. The center axis X1 of the first and second wheels <NUM> and <NUM> may be horizontal to the surface.

The mobile robot apparatus <NUM> may travel toward a front direction or a rear direction according to the first and second wheels <NUM> and <NUM> rotating about the X1 axis, or turn to travel freely to a desired location.

<FIG> is a front perspective view of the mobile robot apparatus of which the body travels to an upper side. <FIG> is a front view of the mobile robot apparatus of which the body is spaced apart from the surface.

Referring to <FIG> and <FIG>, the body <NUM> may move in a vertical direction upward relative to the center axis X1 of the first and second wheels <NUM> and <NUM>. Accordingly, a gap distance with the surface may be further increased for the body <NUM>, and the center of mass of the body <NUM> may be positioned above the center axis X1 of the first and second wheels <NUM> and <NUM>.

That is, because both the bottom surface of the body <NUM> and the caster <NUM> are not in contact with the surface, and only the first and second wheels <NUM> and <NUM> are in contact with the surface from the first and second points S1 and S2, the mobile robot apparatus <NUM> may travel using the first and second points S1 and S2 of the surface in a supported state (two-point support mode).

Accordingly, the body <NUM> may travel efficiently without the body contacting the surface even on surfaces with cushioning such as a carpet because sufficient clearance is secured from the surface. In addition, because sufficient distance to an extent of passing an obstacle between the body <NUM> and the surface is secured, the mobile robot apparatus <NUM> may easily travel while avoiding collisions between the body <NUM> and the obstacles.

<FIG> is an exploded perspective view of a mobile robot apparatus according to an embodiment of the disclosure. <FIG> is a cross-sectional view of the mobile robot apparatus shown in <FIG> taken along line I-I. <FIG> is a side view of a first wheel according to an embodiment of the disclosure. <FIG> is a block view schematically illustrating a control process of the mobile robot apparatus according to an embodiment of the disclosure.

Referring to <FIG>, the first wheel <NUM> may include a first wheel cover <NUM> and a first intermediate member <NUM>, and a second wheel <NUM> may include a second wheel cover <NUM> and a second intermediate member <NUM>. In addition, the mobile robot apparatus <NUM> may further include the first drive device <NUM>, the second drive device <NUM>, and a processor <NUM>.

The first and second wheel covers <NUM> and <NUM> may be respectively connected to the first and second intermediate members <NUM> and <NUM>, which do not rotate relative to the body <NUM>, to be rotatable relative to body <NUM>. In addition, the body <NUM> may be configured such that opposite side surfaces are respectively connected to the first and second intermediate members <NUM> and <NUM> such that the intermediate members are vertically movable relative to body <NUM>.

That is, the first and second wheel covers <NUM> and <NUM> may rotate relative to the first and second intermediate members <NUM> and <NUM>, and the body <NUM> may move vertically relative to the first and second intermediate members <NUM> and <NUM>.

The first and second intermediate members <NUM> and <NUM> may be disposed between the wheel covers <NUM> and <NUM> and the body <NUM>, and may support the first drive device <NUM>, racks <NUM> and <NUM>, and guide rails <NUM> and <NUM>.

The first drive device <NUM> may provide driving force to each of the first and second wheels. The first drive device <NUM> may include a first motor <NUM> which provides driving force to the first wheel <NUM> and a second motor <NUM> which provides driving force to the second wheel <NUM>.

The first motor <NUM> may be disposed on the first intermediate member <NUM> and rotate the first wheel cover <NUM>, and the second motor <NUM> may be disposed on the second intermediate member <NUM> and rotate the second wheel cover <NUM>.

The second drive device may include racks <NUM> and <NUM>, which are disposed in at least one from among the first and second wheels <NUM> and <NUM>, and pinions <NUM> and <NUM>, which are disposed in the body <NUM> to engage with the racks <NUM> and <NUM>.

Specifically, the second drive device <NUM> may include a third motor <NUM>, a first pinion <NUM>, and a first rack <NUM>. The first pinion <NUM> may be disposed in the body <NUM> to engage with the first rack <NUM>, and the first rack <NUM> may be disposed in the first wheel <NUM>.

When the third motor <NUM> rotates the first pinion <NUM>, the first pinion <NUM> may move along the first rack <NUM>. Accordingly, the body <NUM> may move vertically relatively to the first wheel <NUM>.

In addition, the second drive device <NUM> may include a fourth motor <NUM>, a second pinion <NUM>, and a second rack <NUM>. The second pinion <NUM> may be disposed in the body <NUM> to engage with the second rack <NUM>, and the second rack <NUM> may be disposed in the second wheel <NUM>.

When the fourth motor <NUM> rotates the second pinion <NUM>, the second pinion <NUM> may move along the second rack <NUM>. Accordingly, the body <NUM> may move vertically relative to the second wheel <NUM>.

The first and second racks <NUM> and <NUM> may be vertically disposed relative to surface. Accordingly, the body <NUM> may move in a vertical direction with the surface relative to the first and second wheels <NUM> and <NUM>.

In addition, the first and second racks <NUM> and <NUM> may be respectively disposed at the first and second intermediate members <NUM> and <NUM>. Accordingly, because the first and second racks <NUM> and <NUM> maintain a certain shape regardless of the rotation of the first and second wheel covers <NUM> and <NUM>, the body <NUM> may stably move vertically relative to the first and second intermediate members <NUM> and <NUM>.

As described above, as the second drive device includes two pairs of motors <NUM> and <NUM>, pinions <NUM> and <NUM>, and racks <NUM> and <NUM>, the body <NUM> may stably move vertically, and when the mobile robot apparatus <NUM> is turned, the body <NUM> may be tilted and an overturning of the body <NUM> may be prevented as is described below in reference to <FIG> and <FIG>.

In addition, the mobile robot apparatus <NUM> may further include guide rails <NUM> and <NUM> which are disposed in at least one from among the first and second intermediate members <NUM> and <NUM>, and the body <NUM> may include blocks <NUM> and <NUM> which are moveable along the guide rails <NUM> and <NUM> at a side surface.

Specifically, a first guide rail <NUM> may be disposed at the first intermediate member <NUM> and a second guide rail <NUM> may be disposed at the second intermediate member <NUM>. The first and second guide rails <NUM> and <NUM> may be vertically disposed relative to surface.

In addition, the body <NUM> may include a first block <NUM> which is moveable along the first guide rail <NUM> at one side surface and a second block <NUM> which is moveable along the second guide rail <NUM> at the other side surface.

As the first and second blocks <NUM> and <NUM> of the body <NUM> are respectively joined to the first and second guide rails <NUM> and <NUM> and moved, the body <NUM> may move vertically relative to the first and second intermediate members <NUM> and <NUM>. In addition, because the first and second guide rails <NUM> and <NUM> guide a movement pathway of the body <NUM>, the body <NUM> may move vertically more stably.

The mobile robot apparatus <NUM> may include the processor <NUM> for controlling an operation of the mobile robot apparatus <NUM>, and include a sensor for recognizing the surrounding environment and a communication device for communicating with other electronic devices.

The processor <NUM> may control the overall operation of the mobile robot apparatus <NUM>. To this end, the processor may include one or more from among a central processing unit (CPU), an application processor (AP), or a communication processor (CP). The processor may be a micro control unit (MCU).

The processor <NUM> may operate an operating system or an application to control hardware or software elements connected to the processor <NUM>, and may perform various data processing and calculations. In addition, the processor <NUM> may load and process commands or data received from at least one from among other elements on a volatile memory, and store various data in a non-volatile memory.

The processor <NUM> may receive surrounding environment information of the mobile robot apparatus <NUM> received from the camera <NUM> and at least one sensor <NUM>, and control the first drive device <NUM> and the second drive device <NUM> based on the received information. Descriptions of the processor <NUM> controlling the first and second drive devices <NUM> and <NUM> will be described in detail below.

<FIG> is a cross-sectional view of the mobile robot apparatus shown in <FIG> taken along line II-II. <FIG> is a cross-sectional view of the mobile robot apparatus shown in <FIG> taken along line III-III.

Referring to <FIG> and <FIG>, when the mobile robot apparatus <NUM> is required to travel at high speed, or is required to avoid obstacles, the processor <NUM> may control the second drive device <NUM> for the body <NUM> to move body <NUM> up relative to the center axis of the first and second wheels <NUM> and <NUM>. In addition, the processor <NUM> may control the second drive device <NUM> for the caster <NUM> to be selectively in contact with the surface or to be spaced apart from the surface.

Specifically, the processor <NUM> may control the third and fourth motors <NUM> and <NUM> for the first pinion <NUM> to rotate in a first direction (counter-clockwise direction in <FIG>), and the second pinion <NUM> to rotate in a second direction (clockwise direction in <FIG>) which is opposite from the first direction.

Accordingly, because the first and second pinions <NUM> and <NUM> respectively rotate to move upward along the first and second racks <NUM> and <NUM>, the body <NUM> may also move upward relative to the center axis of the first and second wheels <NUM> and <NUM>.

<FIG> and <FIG> are views illustrating a body <NUM> being tilted when the mobile robot apparatus <NUM> is turned. Referring to <FIG> and <FIG>, the processor <NUM> may control the second drive device <NUM> for the body <NUM> to be tilted in a direction to which the mobile robot apparatus <NUM> is turned.

For example, when the mobile robot apparatus <NUM> is turned to a front left side, the processor <NUM> may control the third and fourth motors <NUM> and <NUM> such that the first pinion <NUM> rotates in the first direction (counter-clockwise direction in <FIG>), and the second pinion <NUM> does not rotate. However, the control process of the processor <NUM> is not limited thereto, and the processor <NUM> may control the third and fourth motors <NUM> and <NUM> for the first and second pinions <NUM> and <NUM> to rotate in opposite directions from each other so as to tilt the body <NUM> at a greater angle.

Accordingly, because the first pinion <NUM> moves to the upper side relative to the first rack <NUM>, the body <NUM> may be tilted in a direction to which the mobile robot apparatus <NUM> is turned (-X direction in <FIG>). That is, because the body <NUM> is tilted in an opposite direction from a centrifugal force based on turning, the overturning of the mobile robot apparatus <NUM> may be prevented.

<FIG>, <FIG>, and <FIG> are views illustrating a process of the body <NUM> returning to its original position when having fallen.

Referring to <FIG>, based on the body <NUM> falling as it rotates in a first direction R1 while the mobile robot apparatus <NUM> is moving in the two-point support mode described above, the body <NUM> may be in contact with the surface from a first contact point B. At this time, the first and second wheels <NUM> and <NUM> may be in contact with the surface from a second contact point W.

The processor <NUM> may control the second drive device <NUM> for the first and second wheels <NUM> and <NUM> to move toward the body <NUM> until the center of mass M of the body <NUM> is positioned outside of a section C between the first contact point B of the body <NUM> and the second contact point W of the first and second wheels <NUM> and <NUM>.

Specifically, the body <NUM> may be stopped in its place, and the center axis X1 of the first and second wheels <NUM> and <NUM> may move in a direction toward the center of mass M of body <NUM>. Accordingly, as the second contact point W of the first and second wheels <NUM> and <NUM> becomes closer with the first contact point B of the body <NUM>, the center of mass M of the body <NUM> may be positioned outside of the section C between the first and second contact points B and W.

The body <NUM> may be applied with a restoring torque in the second direction R2 that is opposite from the first direction R1 to which the body fell by gravity which acts on the center of mass M positioned at the outside of the contact section C based on the contact section C. Accordingly, the mobile robot apparatus <NUM> may again return to its position prior to falling as shown in <FIG>.

The above-described control process is based on the scenario wherein body <NUM> falls in the first direction R1 toward the "front" direction, but the direction to which the body <NUM> falls is not limited thereto, and may fall toward the rear direction. Even when the body <NUM> falls toward the rear direction, the above-described control process may be identically applied, and the mobile robot apparatus <NUM> may return to its position prior to falling.

Claim 1:
A mobile robot apparatus (<NUM>) comprising:
A body (<NUM>);
a first wheel (<NUM>) and a second wheel (<NUM>) disposed respectively at opposite side surfaces of the body;
a first drive device (<NUM>) configured to provide driving force to each of the first and second wheels;
a second drive device (<NUM>) configured to move the body in a vertical direction based on a center axis of the first and second wheels; and
a processor (<NUM>) configured to control the second drive device for the body to move by contacting with a surface, or move spaced apart from the surface
wherein the second drive device comprises,
a rack (<NUM>, <NUM>) disposed in at least one from among the first and second wheels, and
a pinion (<NUM>, <NUM>) disposed in the body to engage with the rack.