KR20080001002A - Robot cleaner system and method of controlling the same - Google Patents

Abstract

A robot cleaner system and a method of controlling the same are provided to move a robot cleaner, and to control the positions accurately by installing a plurality of signal transmitting parts in several places to be cleaned and controlling the specific signal transmitting parts to transmit signals and to guide the robot cleaner. A station transmits signals of pre-set frequencies through signal transmitting parts. A robot cleaner receives the signals transmitted from the station through the signal receiving parts. The signal receiving parts judge whether the Doppler shift effect is observed(708). Directions to which the signal transmitting parts are placed are detected on the basis of the observed result of the Doppler shift effect(710). The signal receiving parts include antennas for receiving the signals from the signal transmitting parts. The antennas are moved along the rotation track of the robot cleaner.

Description

ROBOT CLEANER SYSTEM AND METHOD OF CONTROLLING THE SAME

1 is a perspective view showing a robot cleaner system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control system of the robot cleaner system shown in FIG. 1. FIG.

3 is a view for explaining the principle of direction detection using the Doppler shift effect in the robot cleaner system according to the present invention.

4 is a graph showing a change in frequency with respect to time in one rotating antenna.

5 is a view for explaining the direction detection through the observation of the Doppler shift effect when the robot cleaner according to an embodiment of the present invention.

6 is a view for explaining the direction detection through the observation of the Doppler shift effect while the robot cleaner according to an embodiment of the present invention.

7 is a flowchart illustrating a control method of a robot cleaner system according to an exemplary embodiment of the present invention.

* Description of the symbols for the main parts of the drawings

100: robot cleaner

102: docking station

150: transmitter

160: receiver

160a-160d: Antenna

160e: rotating body

The present invention relates to a robot cleaner system and a control method thereof, and more particularly, to a movement and / or position control of a robot cleaner that autonomously moves an area to be cleaned and performs automatic cleaning.

The robot cleaner refers to a device that performs a cleaning operation of sucking dust, foreign substances, etc. from the floor surface while traveling by itself in a certain range of working areas without a user's manipulation. The robot cleaner uses sensors or cameras to determine the distance to obstacles such as furniture, office supplies, and walls installed in a work area such as a home or an office, and uses the determined information to drive the robot cleaner so that it does not collide with the obstacle. Do this.

When the robot cleaner autonomously moves the area to be cleaned and performs automatic cleaning, and needs to move to a specific location within the area, conventionally, the robot cleaner detects an RF signal generated from a radio frequency (RF) signal generator set at a specific location. The installation position of the RF signal generator was detected and the robot cleaner was moved in the direction, or the entire image in the area was acquired through the camera, and the image was analyzed to perform the movement and / or position control of the robot cleaner.

However, when the detection of the RF signal is used, the transmission distance of the RF signal is relatively short and the reception sensitivity decreases due to obstacles, which is not suitable when the area to be cleaned is large or complicated structure. Software of complex algorithms for analysis is required, resulting in high cost.

The robot cleaner system and control method thereof according to the present invention have the purpose of lowering the production cost, improving the sensing distance, and enabling more accurate movement and position control of the robot cleaner.

Robot cleaner system according to the present invention for this purpose, the robot cleaner; A station; The robot cleaner and the station either transmit a signal having a preset frequency and the other detects the direction in which the sender is transmitting the signal based on the Doppler shift effect observed at the receiver receiving the signal. do.

In addition, the aforementioned station further includes a transmitter for transmitting a signal of a preset frequency; The robot cleaner further includes a receiver that is movably installed to observe the Doppler shift effect of the received signal while receiving a signal transmitted from the transmitter of the station; The direction in which the station is located is detected based on the Doppler shift effect observed at the receiver.

The receiver further includes an antenna for receiving a signal transmitted from the station.

In addition, the above-described movement of the receiver is such that the antenna of the receiver moves along the rotation trajectory of the robot cleaner by rotating the robot cleaner in a stopped state.

In addition, the above-mentioned receiving unit further includes a rotating body fixed to the antenna, provided to be rotated to the robot cleaner; The movement of the receiver moves the antenna of the receiver along the rotational trajectory of the rotor by the rotation of the rotor.

In addition, the above-described movement of the receiver is such that the antenna moves together along the movement trajectory of the robot cleaner by the robot cleaner moving by a predetermined displacement.

The receiver may further include a frequency detector for detecting a frequency of a signal received by the receiver; The apparatus may further include a direction detector configured to detect a direction in which the station is located by generating a direction information by comparing the frequency detected by the frequency detector with a frequency of a signal transmitted from the station.

In addition, the direction detector described above recognizes the direction indicated by the antenna when the Doppler shift effect is not observed at the frequency detected by the frequency detector as the direction in which the station is located.

이 다음의 수식으로 표현된다.In addition, the angle between the front direction of the robot cleaner and the direction in which the station is located when the antenna described above is observed by moving the antenna along one of the rotating track of the robot cleaner and the rotating track of the rotating body is made.

This is expressed by the following formula.

은

의 각속도이며,

은 자전 궤도를 따라 이동하는 안테나가 로봇 청소기의 전면 방향에 위치할 때의 신호의 진행 방향과 평행한 방향의 안테나의 선속도)Where r is the distance from the rotating shaft of either the rotor or the robot cleaner to the antenna,

silver

Angular velocity of,

Is the linear velocity of the antenna in a direction parallel to the direction of signal propagation when the antenna moving along the rotating track is located in the front direction of the robot cleaner.)

가 다음의 수식으로 표현된다.In addition, when the above-described antenna is moved along the movement trajectory by a predetermined displacement of the robot cleaner, the angle between the front direction of the robot cleaner and the direction in which the station is located is made.

Is expressed by the following formula.

는 로봇 청소기의 이동 변위를 대표하는 벡터

의 x 방향의 선속도이고, x 방향은 스테이션으로부터 발신되는 신호의 진행 방향과 평행하며, 상기

는 벡터

의 크기(즉 속력))(only,

A vector representing the displacement of a robot cleaner

Is the linear velocity in the x direction of, wherein the x direction is parallel to the advancing direction of the signal originating from the station,

Vector

Size (i.e. speed)

In addition, when there are two or more antennas described above, two or more antennas are provided at equal intervals from each other.

In addition, the above-described station is a docking station for charging and discharging the foreign matter of the robot cleaner.

The control method of the robot cleaner system according to the present invention for the above object. A robot cleaner system comprising a robot cleaner and a station; One of the robot cleaner and the station transmits a signal of a preset frequency and the other receives the signal; Based on the Doppler shift effect observed at the receiving side receiving the signal, the direction in which the transmitting side transmitting the signal is located is detected.

In addition, the aforementioned station transmits a signal of a preset frequency through the transmitter; The robot cleaner receives a signal from the station through the receiver; Determine whether a Doppler shift effect is observed at the receiver; The direction in which the station is located is detected based on the observation result of the Doppler shift effect.

The receiver further includes an antenna for receiving a signal transmitted from the station.

In addition, the above-described movement of the receiver is such that the antenna of the receiver moves along the rotation trajectory of the robot cleaner by rotating the robot cleaner in a stopped state.

In addition, the above-mentioned receiving unit further includes a rotating body fixed to the antenna, provided to be rotated to the robot cleaner; The movement of the receiver moves the antenna of the receiver along the rotational trajectory of the rotor by the rotation of the rotor.

In addition, the above-described movement of the receiver is such that the antenna moves together along the movement trajectory of the robot cleaner by the robot cleaner moving by a predetermined displacement.

Further, the direction indicated by the antenna when the Doppler shift effect is not observed at the frequency of the signal received at the receiver is recognized as the direction in which the station is located.

이 다음의 수식으로 표현된다.In addition, the angle between the front direction of the robot cleaner and the direction in which the station is located when the above-described antenna is moved along one of the rotating track of the robot cleaner and the rotating track of the rotating body to observe the Doppler shift effect.

This is expressed by the following formula.

은

의 각속도이며,

은 자전 궤도를 따라 이동하는 안테나가 로봇 청소기의 전면 방향에 위치할 때의 신호의 진행 방향과 평행한 방향의 안테나의 선속도임)Where r is the distance from the rotating shaft of either the rotor or the robot cleaner to the antenna,

silver

Angular velocity of,

Is the linear velocity of the antenna in a direction parallel to the signal propagation direction when the antenna moving along the rotating track is located in the front direction of the robot cleaner.)

가 다음의 수식으로 표현된다.In addition, when the above-described antenna is moved along the movement trajectory by a predetermined displacement of the robot cleaner, the angle between the front direction of the robot cleaner and the direction in which the station is located is made.

Is expressed by the following formula.

는 로봇 청소기의 변위를 대표하는 벡터

의 x 방향의 선속도이고, x 방향은 스테이션으로부터 발신되는 신호의 진행 방향과 평행하며, 상기

는 벡터

의 크기(즉 속력))(only,

Vector representing displacement of robot cleaner

Is the linear velocity in the x direction of, wherein the x direction is parallel to the advancing direction of the signal originating from the station,

Vector

Size (i.e. speed)

When described with reference to Figures 1 to 7 a preferred embodiment of the present invention made as described above. 1 is a perspective view showing a robot cleaner system according to an embodiment of the present invention. As shown in FIG. 1, the robot cleaner system consists of a robot cleaner 100 and a docking station 102. The robot cleaner 100 sucks and cleans foreign substances on the floor by using suction power by rotation of the fan and / or static electricity by the charging device while moving the indoor space, and the docking station 102 uses the robot cleaner 100. To charge the battery and discharge the foreign objects.

An electric wheel (not shown) is installed below the robot body 104 to move the robot cleaner 100, which is driven by a driving motor (not shown) so that the robot cleaner 100 moves and rotates linearly. You can exercise and rotate. In addition, an obstacle detecting sensor 106 such as an infrared sensor or an ultrasonic sensor is installed outside the robot body 104 to avoid obstacles during movement. An opening 108 is provided on the side of the robot body 104 to discharge the sucked foreign matter stored in the robot cleaner 100 to the docking station 100. The robot cleaner 100 couples the opening 108 to the suction port 110 of the docking station 102 and then discharges the foreign matter inside the robot cleaner 100 to the docking station 102.

A guide member 112 is provided in front of the docking station 102 to guide the docking of the robot cleaner 100. The guide member 112 is provided with a connection terminal 114 to charge the rechargeable battery provided in the robot cleaner 100.

When the robot cleaner 100 autonomously moves the area to be cleaned and performs the automatic cleaning, when the amount of foreign substances sucked up is large and needs to be discharged or the capacity of the rechargeable battery is reduced, the robot cleaner 100 needs to be charged. Or, when the cleaning is completed, return to the docking station 102 to perform the desired work (emission of foreign matter, charging the battery, waiting for the next work, etc.). In order to return to the docking station 102 at any place remote from the docking station 102, the robot cleaner 100 must obtain at least orientation information of the docking station 102. In the robot cleaner system according to an exemplary embodiment of the present invention, a Doppler Shift Effect is used by the robot cleaner 100 to obtain direction information of the docking station 102. That is, based on the Doppler shift effect observed at the receiving side of the signal when transmitting and receiving the signal between the robot cleaner 100 and the docking station 102, the direction information on the transmitting side is obtained, and the robot cleaner ( Control the movement direction and position of 100).

To this end, the docking station 102 of the robot cleaner system shown in FIG. 1 is provided with a transmitter 150 for transmitting radio waves of a predetermined constant frequency, and the robot cleaner 100 is an transmitter 150 of the docking station 102. Receiving unit 160 for receiving a radio wave transmitted from) is provided. Of course, sound waves may be used instead of radio waves. In the receiver 160 of the robot cleaner 100, all four antennas 160a to 160d are installed at equal intervals on the ring-shaped rotating body 160e, and the rotating body 160e at a predetermined constant speed. As it rotates, these four antennas 160a-160d also move along a fixed track. The rotating body 160e for moving the antennas 160a-160d is also not necessarily ring-shaped, and may be any other type as long as the structure can move the antennas 160a-160d along a predetermined track. In addition, instead of using the rotating body 160e, the entire robot cleaner 100 may rotate to allow the antennas 160a to 160d to move. The receiver 160 shown in FIG. 1 further includes a frequency detector and a direction detector in addition to the antennas 160a-160d and the rotating body 160e. The frequency detector and the observer will be described in the description of FIG. 2.

FIG. 2 is a block diagram illustrating a control system of the robot cleaner system illustrated in FIG. 1. As shown in FIG. 2, the docking station 102 includes a transmitter 150 and a charger 202. As described in the description of FIG. 1, the transmitter 150 transmits a radio wave of a preset frequency. The charging unit 202 converts the commercial AC power input from the outside into power for charging the charging battery 210 of the robot cleaner 100 so that the charging battery 210 of the robot cleaner 100 may be charged.

The control system of the robot cleaner 100 is configured based on the controller 214 that controls the overall operation of the robot cleaner 100. On the input side of the controller 214, the frequency detector 204, the direction detector 206, the movement distance detector 208, the battery remaining amount detector 212, the obstacle detector 106, the foreign matter collection amount detector 216, and the like are the controller 214. Is electrically connected to enable communication. The frequency detector 204 receives a radio wave of a predetermined frequency transmitted from the transmitter 150 of the docking station 102 to detect the frequency of the received radio wave. Since the antennas 160a-160d of the robot cleaner 100 move on a circular orbit, the frequency (Doppler frequency) of the radio wave actually detected by the antennas 160a-160d depends on the position of the antennas 160a-160d. The shift effect may have a value different from the frequency (raw frequency) of the radio wave transmitted from the transmitter 150. The direction detecting unit 206 detects the direction of the transmitting unit 150 of the docking station 102 (that is, the direction of the radio wave transmitting position) on the basis of the frequency detected by the frequency detecting unit 204 and controls the direction information thereof. To provide. The movement distance detector 208 detects the distance traveled by the robot cleaner 208 and provides the information to the controller 214. The movement distance of the robot cleaner 100 determines the amount of rotation of the electric wheel 218 through the encoder. It can also be detected and detected. The battery remaining amount detector 212 detects the remaining charge level of the rechargeable battery 210 and provides the remaining amount information to the controller 214. When the controller 214 determines that the remaining charge of the rechargeable battery 210 is low and needs to be charged, the controller 214 stops the current operation of the robot cleaner 100 and returns to the docking station 102 to charge the rechargeable battery 210. The robot cleaner 100 is controlled to charge. The obstacle detector 106 detects whether an obstacle exists in the front while the robot cleaner 100 moves and provides obstacle information to the controller 214. The controller 214 changes the movement path so that the robot cleaner 100 bypasses the obstacle based on the obstacle information so that the robot cleaner 100 does not stop the operation due to the obstacle. The foreign matter collection amount detecting unit 216 detects the amount of the foreign matter collected in the robot cleaner 100 and provides the foreign matter collection amount information to the controller 214. The controller 214 checks the amount of the foreign matter currently loaded in the robot cleaner 100 through the foreign matter collection amount information, and when the amount of the foreign matter currently loaded reaches the maximum loading amount that the robot cleaner 100 itself can store. The robot cleaner 100 is controlled to stop further cleaning work and return to the docking station 102 to perform the foreign matter discharge operation.

The rotating body 160e, the electric wheel 218, and the reduction unit 220 are connected to the output side of the control unit 214. The rotating body 160e is one of the components of the receiver 160 mentioned with reference to FIG. 1 and is used to move the antennas 160a-160d along a predetermined track. The electric wheel 218 is for the movement of the robot cleaner 100, and includes a driving wheel for forward or backward and a direction change wheel for direction change. The dust collecting unit 220 is provided to face the lower part of the robot cleaner 100, and sucks foreign substances on the bottom surface of the area to be cleaned to be loaded into the foreign matter loading space inside the robot cleaner 100.

The electric wheel 218 consisting of a driving wheel and a turning wheel allows the robot cleaner 100 to rotate in a stationary state. Therefore, by using the operation characteristics of the robot cleaner 100, the antennas 160a-160d may be rotated by rotating the robot cleaner 100 itself without using the rotating body 160e of the receiver 160.

3 is a view for explaining the principle of direction detection using the Doppler shift effect in the robot cleaner system according to the present invention. The Doppler shift effect is observed at the receiver side when there is relative movement between the signal source and the receiver. When the source and receiver are close to each other, the frequency of the signal received by the receiver increases relative to the source frequency of the signal from which the source originates. On the contrary, when the signal source and the receiver move away from each other, the frequency of the signal received by the receiver decreases relative to the original frequency of the signal transmitted by the signal source. If there is no relative movement between the signal source and the receiver, the frequency of the signal transmitted from the signal source and the signal received by the receiver are the same, so no Doppler shift effect is observed on the receiver side.

In FIG. 3, the circle 304 with the midpoint 302 corresponds to the trajectory created by the antennas 160a-160d of FIG. 1 physically rotating along the direction of the arrow 306, and the arrow 308 is the transmitter. It is a traveling direction of a signal (radio wave) transmitted from 150.

When any one of the four antennas 160a-160d (eg, 160a) is located at point a, the instantaneous component of the antenna 160a is in the direction of the arrow A, and the velocity component of the antenna 160a at point a Is orthogonal to the direction 308 in which the signal (radio wave) transmitted from the transmitter 150 proceeds. Therefore, no Doppler shift effect is observed at point a.

When the antenna 160a is located at the point b which is 90 ° to the point a, the antenna 160a moves in the direction of the arrow B which is the same as the traveling direction 308 of the signal (propagation) transmitted from the transmitter 150. Move away from bride 150. Therefore, when the antenna 160a is located at point b, a maximum decrease in frequency occurs in the signal (propagation) received by the antenna 160a, which is due to the Doppler shift effect described above.

Antenna 160a has a velocity component in the direction of the C arrow when antenna 160a is located at point c, which is 90 ° to point b. As with the antenna 160a located at point a, the velocity component of the antenna 160a when located at point c is perpendicular to the direction of travel 308 of the signal (propagation) transmitted from the transmitter 150. Will be achieved. Therefore, when the antenna 160a is located at the c point, the Doppler shift effect is not observed as in the case of the a point.

When the antenna 160a is located at point d, the antenna 160a has a velocity component in the direction of the D arrow toward the transmitter 150. Therefore, a maximum increase in frequency occurs in a signal (radio wave) received by the antenna 160a, which is also due to the Doppler shift effect described above.

Of course, the Doppler shift effect will also be observed at locations other than a, b, c, and d points on the trajectory where the antennas 160a-160d rotate, but in particular, the maximum decrease and maximum increase in frequency at the b and d positions, respectively, described above. Is observed, and no increase or decrease in frequency is observed at positions a and c.

FIG. 4 is a graph illustrating a change in frequency with respect to time in one rotating antenna. The graph shows a frequency value corresponding to each position of the rotating antenna. As shown in FIG. 4, when one of the four antennas 160a-160 is positioned at point b, the reception frequency is minimum, and when it is located at point d, the reception frequency is maximized. That is, by checking the rotation angle of the antenna (160a-160d) with respect to the reference position at point a, it is possible to determine the traveling direction of the signal (radio wave) transmitted from the transmitter 150, so that the antenna (160a-160d) The direction of the transmitter 150 may also be determined.

In order to obtain a graph as shown in FIG. 4, signal information from each of the four antennas 160a to 160d may be combined. In other words, when the Doppler shift effect is observed by rotating only one antenna, the antenna can be obtained as shown in FIG. 4 only when the antenna is completely circled on the rotational track, but as shown in FIG. 1, the four antennas 160a-160d are rotated. If the rotating body 160e is rotated by equidistantly spaced on the entire body 160e, a graph as shown in FIG. 4 can be obtained by only one quarter rotation of the rotating body 160e.

From another point of view, one rotation of the rotor 160e of the receiver 160 as shown in FIG. 1 repeats the observation for each section divided into a, b, c, and d in FIG. Can be implemented so that more accurate observations of the Doppler shift effect can be made. As a result, as the number of antennas increases, the observation time of the Doppler shift effect is shortened, and more accurate observation of the Doppler shift effect is possible.

을 알면 로봇 청소기(100)의 진행 방향을 -

만큼 보정하여 전진함으로써 로봇 청소기(100)가 x축 방향 즉 도킹 스테이션(102)의 발신부(150)를 향해 이동하도록 할 수 있다. 도 5에서 a 지점과 a' 지점 사이의 각도

은 다음의 식 1과 같이 나타낼 수 있다.5 is a view for explaining the direction detection through observation of the Doppler shift effect when the robot cleaner according to an embodiment of the present invention. In FIG. 5, the x-axis is parallel to the traveling direction of the radio wave 502 transmitted from the transmitting unit 150 of the docking station 102, and the robot cleaner 100e of the receiving unit 160 is stopped while the robot cleaner 100 is stopped. The four antennas 160a-160d also rotate at constant speed in the direction of arrow 504 as. At this time, at least one of the four antennas 160a to 160d rotating at constant speed (for example, 160a) reaches a 'point through a point on the x-axis. Point a in FIG. 5 is a point where the Doppler shift effect is not observed at all, similar to point a in FIG. 3, and point a 'is a point where the Doppler shift effect (frequency reduction) is observed by the displacement of Δd of the antenna 160a. Location. Therefore, when the a 'position is the front of the robot cleaner 100, the angle between the point a and the point a'

Knowing the direction of the robot cleaner 100-

The robot cleaner 100 may move toward the transmitter 150 of the docking station 102 in the x-axis direction by correcting and moving forward. Angle between point a and point a 'in FIG.

Can be expressed as in Equation 1 below.

(Equation 1)

는 a 지점에서 a' 지점으로 이동하는 안테나(160a)의 x 방향의 선속도이고,

는 a 지점에서 a' 지점으로 이동하는 안테나(160a)의 각속도이며, r은 회전체(160e)의 자전 축(506)에서 안테나(160a)까지의 거리이다. 안테나(160a)는 일정한 궤도상에서 등속 회전하기 때문에 수신부(160)의 제품 규격을 통해 각속도

과 거리 r을 모두 알 수 있다.In equation 1,

Is the linear velocity in the x direction of the antenna 160a moving from point a to point a ',

Is the angular velocity of the antenna 160a moving from point a to point a ', and r is the distance from the rotating shaft 506 of the rotating body 160e to the antenna 160a. Since the antenna 160a rotates at a constant speed in a constant track, the angular velocity is determined through the product specification of the receiver 160.

We can know both and distance r.

은 다음의 식 (2)를 통해 알 수 있다.Also linear speed

Is given by the following equation (2).

(Equation 2)

는 매질에서의 신호의 진행 속도 이고,

는 수신자의 속도이며, ±는 신호원과 수신자가 서로 가까워질 때(+)와 서로 멀어질 때(-)를 의미한다. 도 5에 나타낸 실시 예에서,

는 공기 중에서의 전파의 진행 속도이고,

는 안테나(160a-160d)의 회전 속도에 해당된다. 다만 도플러 쉬프트 효과는 신호원과 수신자 사이의 상대적인 속도 즉, 도 5의 x 축 방향의 속도 성분에만 영향을 받으므로 식 2의

(수신자의 속도)는 곧 식 1의

(안테나의 x축 방향 속도)과 같다고 할 수 있다. 결국 식 2에서 f와 f',

의 값을 알고 있으므로 이를 통해

(=

)의 값을 알 수 있다. 이와 같은 조건들을 식 1에 대입하면 각도

의 크기를 알 수 있다. 따라서 a‘ 지점이 로봇 청소기(100)의 정면일 때 각도

을 알면 로봇 청소기(100)의 정면(a' 지점)을

만큼 시계 방향으로 회전시켜서 진행하면 로봇 청소기(100)가 x축을 따라 이동하는 것이 되어 신호원인 도킹 스테이션(102)에 귀환할 수 있다.In Equation 2 above, f is the original frequency of the signal originating from the signal source, f 'is the frequency (Doppler frequency) received by the receiver,

Is the speed of signal propagation in the medium,

Is the speed of the receiver, ± means the signal source and receiver are closer (+) and farther (-). In the embodiment shown in FIG. 5,

Is the speed of propagation in air,

Corresponds to the rotation speed of the antenna (160a-160d). However, the Doppler shift effect is only affected by the relative velocity between the signal source and the receiver, that is, the velocity component in the x-axis direction of FIG.

(Receiver's speed) soon coming out of equation 1

It can be said to be equal to (antenna's x-axis speed). Eventually f and f 'in equation 2,

Since we know the value of

(=

You can see the value of). Substituting these conditions into Eq. 1

You can see the size. Therefore, when the a 'point is the front of the robot cleaner 100, the angle

If you know the front of the robot cleaner (a 'point)

By rotating clockwise as much as the robot cleaner 100 moves along the x axis, the robot cleaner 100 may return to the docking station 102 that is a signal source.

는 로봇 청소기(100)의 이동 방향 및 속도를 대표하는 벡터이다. 이 때 로봇 청소기(100)의 진행 방향과 전파(602)의 진행 방향 사이의 각도

는 다음의 식 3과 같이 나타낼 수 있다.6 is a view for explaining the direction detection through observation of the Doppler shift effect while the robot cleaner according to an embodiment of the present invention moves. In FIG. 6, the x-axis is parallel to the direction of travel of the propagation 602 originating from the originator 150 of the docking station 102, the vector

Is a vector representing the moving direction and the speed of the robot cleaner 100. At this time, the angle between the traveling direction of the robot cleaner 100 and the traveling direction of the radio wave 602

Can be expressed as in Equation 3 below.

(Equation 3)

는 벡터

의 x 방향의 선속도이며,

는 벡터

의 크기(즉 속력)이다. 선속도

는 식 2에서

(=

)를 구한 것과 같은 방법으로 구할 수 있고, 로봇 청소기(100)의 속력

는 자체적으로 알 수 있으므로, 결국 선속도

와 속력

를 통해 각도

를 알 수 있다. 따라서 벡터

의 방향이 로봇 청소기(100)의 정면일 때 각도

를 알면 로봇 청소기(100)의 정면을 -

만큼 시계 방향으로 회전시켜서 진행하면 로봇 청소기(100)가 x축을 따라 이동하는 것이 되어 신호원인 도킹 스테이션(102)에 귀환할 수 있다.In Equation 3 above,

Vector

Is the linear velocity in the x direction of

Vector

Is the size (ie speed) of. Linear velocity

In equation 2

(=

) Can be obtained in the same way as, and the speed of the robot cleaner 100

Is known by itself, so in the end

And speed

Angle through

It can be seen. Thus vector

When the direction of the is the front of the robot cleaner 100, the angle

Knowing the front of the robot cleaner (100)-

By rotating clockwise as much as the robot cleaner 100 moves along the x axis, the robot cleaner 100 may return to the docking station 102 that is a signal source.

7 is a flowchart illustrating a control method of a robot cleaner system according to an exemplary embodiment of the present invention. As shown in FIG. 7, the robot cleaner 100 autonomously moves the area to be cleaned and performs automatic cleaning (702). When the controller 214 of the robot cleaner 100 needs to discharge a large amount of foreign substances sucked during the automatic cleaning or needs to be discharged or the capacity of the rechargeable battery decreases, the controller 214 may perform cleaning. When completed, the operation mode of the robot cleaner 100 is switched to the return mode for returning to the docking station 102 (704). When the robot cleaner 100 is switched to the feedback mode (YES in 704), the controller 214 checks whether the robot cleaner 100 is in the stopped state or the moved state (706).

If the robot cleaner 100 is currently stopped, the Doppler shift effect is observed through the frequency detection of radio waves received by the rotating antennas 160a-160d by rotating the antennas 160a-160d in the stopped state (708). ). The observation result of the Doppler shift effect is applied to Equation 1 mentioned in the above description of FIG. 5 to detect the direction of the signal source, that is, the direction of the docking station 102 (710). When the direction of the docking station 102 is detected, the controller 214 controls the movement direction of the robot cleaner 100 so that the robot cleaner 100 can move in the direction of the detected docking station 102 (712). .

On the contrary, when the robot cleaner 100 is currently in a moving state, observation of the Doppler shift effect accompanying the relative movement between the antennas 160a-160d and the transmitter 150 generated by the movement of the robot cleaner 100 itself is performed. Perform 714. The observation result of the Doppler shift effect is applied to Equation 3 mentioned in the above description of FIG. 5 to detect the direction of the signal source, that is, the direction of the docking station 102 (716). When the direction of the docking station 102 is detected, the controller 214 controls the movement direction of the robot cleaner 100 so that the robot cleaner 100 can move toward the detected docking station 102 (718).

The robot cleaner 100 checks whether there is an obstacle on the path to be moved while moving toward the docking station 102 (720). If it is determined that an obstacle exists on the path to be proceeded (YES in 720), the obstacle avoidance driving operation is performed (722). In addition, since the direction information of the docking station 102 may be lost during the obstacle avoidance driving process, return to block 706 to acquire new direction information of the docking station 102 and attempt to return. If there is no obstacle on the path to proceed (No in 720), the robot moves to the docking station 102 according to the current direction information and ends the return mode when the feedback is completed (724). After exiting the return mode, foreign substances are discharged, the battery is charged, and the standby mode is performed according to the return purpose.

In the robot cleaner system according to an exemplary embodiment of the present invention, the installation position of the transmitter (signal source) that generates a signal having a predetermined frequency need not be limited to the docking station 102. That is, the robot cleaner 100 may be guided to the installation position of the corresponding transmitter by controlling a plurality of transmitters to be installed in various other places in the area to be cleaned to transmit radio waves only from the specific transmitter as necessary. This application is convenient because it can guide the robot cleaner 100 to clean a specific area of the building is divided into several zones.

The robot cleaner system and its control method according to the present invention can lower the production cost, improve the sensing distance, and enable more accurate movement and position control of the robot cleaner.

Claims (21)

A robot cleaner; A station; One of the robot cleaner and the station transmits a signal having a preset frequency and the other sends the signal based on the Doppler shift effect observed at the receiving side receiving the signal while receiving the signal. Robotic cleaner system to detect the direction in which it is located. The method of claim 1, The station further comprises a transmitter for transmitting a signal of the preset frequency; The robot cleaner further includes a receiver that is movably installed to observe a Doppler shift effect of the received signal while receiving a signal transmitted from the transmitter of the station; And a robot cleaner system detecting a direction in which the station is located based on the Doppler shift effect observed by the receiver. The method of claim 2, wherein the receiving unit, And a antenna for receiving a signal originating from the station. The method of claim 3, wherein The movement of the receiver is a robot cleaner system in which the antenna of the receiver moves along the rotation trajectory of the robot cleaner by rotating the robot cleaner in a stopped state. The method of claim 3, wherein the receiving unit, The antenna is fixedly installed, and further includes a rotating body provided to be rotatable to the robot cleaner; The movement of the receiver is a robot cleaner system in which the antenna of the receiver moves along the rotational trajectory of the rotor by the rotation of the rotor. The method of claim 3, wherein The movement of the receiver is a robot cleaner system that the antenna moves along the movement trajectory of the robot cleaner by moving the robot cleaner by a predetermined displacement. The method of claim 3, wherein the receiving unit, A frequency detector for detecting a frequency of the signal received by the receiver; And a direction detector configured to detect a direction in which the station is located by generating a direction information by comparing a frequency detected by the frequency detector with a frequency of a signal transmitted from the station. The method of claim 7, wherein the direction detecting unit, And a robot cleaner system that recognizes the direction indicated by the antenna when the Doppler shift effect is not observed at the frequency detected by the frequency detector. The method of claim 3, wherein The angle between the front direction of the robot cleaner and the direction in which the station is located when the antenna is moved along one of the rotating track of the robot cleaner and the rotating track of the rotating body to observe the Doppler shift effect.

Robot cleaner system represented by the following formula.

(Wherein r is a distance from the rotating shaft of any one of the rotating body and the robot cleaner to the antenna,

Said above

Angular velocity of and

Is the linear velocity of the antenna in a direction parallel to the traveling direction of the signal when the antenna moving along the rotating trajectory is located in the front direction of the robot cleaner. The method of claim 3, wherein The angle between the front direction of the robot cleaner and the direction in which the station is located when the antenna is moved along the movement trajectory by the predetermined displacement of the robot cleaner is made to observe the Doppler shift effect.

The robot cleaner system is represented by the following formula.

(However,

Is a vector representing the displacement of the robot cleaner

Is the linear velocity in the x direction of, wherein the x direction is parallel to the advancing direction of the signal originating from the station,

Said vector

Size (i.e. speed) The method of claim 3, wherein When the two or more antennas, the two or more antennas are installed at equal intervals between the robot cleaner system. The method of claim 1, And the station is a docking station for charging and discharging the robot cleaner. A method of controlling a robot cleaner system comprising a robot cleaner and a station; One of the robot cleaner and the station sends a signal of a preset frequency and the other receives the signal; And a control method of a robot cleaner system for detecting a direction in which a transmitting side transmitting the signal is located based on a Doppler shift effect observed at a receiving side receiving the signal. The method of claim 13, The station sends a signal of the preset frequency through a transmitter; The robot cleaner receives a signal from the station through a receiver; Determine whether a Doppler shift effect is observed at the receiver; And a control method of a robot cleaner system for detecting a direction in which the station is located based on an observation result of the Doppler shift effect. The method of claim 14, wherein the receiving unit, And a antenna for receiving a signal originating from the station. The method of claim 15, The movement of the receiver is a robot cleaner system control method of the robot cleaner to rotate along the rotational trajectory of the robot cleaner by rotating the robot cleaner in the stopped state. The method of claim 15, wherein the receiving unit, The antenna is fixedly installed, and further includes a rotating body provided to be rotatable to the robot cleaner; The movement of the receiver is a control method of the robot cleaner system in which the antenna of the receiver moves along the rotational trajectory of the rotor by the rotation of the rotor. The method of claim 15, The movement of the receiving unit is a control method of the robot cleaner system that the antenna moves along the movement trajectory of the robot cleaner by moving the robot cleaner by a predetermined displacement. The method of claim 15, And controlling the robot cleaner system to recognize the direction indicated by the antenna when the Doppler shift effect is not observed at the frequency of the signal received by the receiver. The method of claim 15, The angle between the front direction of the robot cleaner and the direction in which the station is located when the antenna is moved along one of the rotating track of the robot cleaner and the rotating track of the rotating body to observe the Doppler shift effect.

The control method of the robot cleaner system represented by this following formula.

(Wherein r is a distance from the rotating shaft of any one of the rotating body and the robot cleaner to the antenna,

Said above

Angular velocity of and

Is the linear velocity of the antenna in a direction parallel to the traveling direction of the signal when the antenna moving along the rotating trajectory is located in the front direction of the robot cleaner.) The method of claim 15, The angle between the front direction of the robot cleaner and the direction in which the station is located when the antenna is moved along the movement trajectory by the predetermined displacement of the robot cleaner is made to observe the Doppler shift effect.

The control method of the robot cleaner system represented by the following formula.

(However,

Is a vector representing the displacement of the robot cleaner

Is the linear velocity in the x direction of, wherein the x direction is parallel to the advancing direction of the signal originating from the station,

Said vector

Size (i.e. speed)

Images