KR20080001001A - 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 to places to be cleaned, and to clean the places automatically by detecting directions to which at least three signal transmitting parts are placed on the basis of the observed result of a Doppler shift effect. Signals of characteristic frequencies pre-set from at least three signal transmitting parts are transmitted(702). A robot cleaner receives signals transmitted from the three signal transmitting parts through signal receiving parts. The signal receiving parts judge whether the Doppler shift effect is observed(704). Directions to which the signal transmitting parts are placed are detected on the basis of the observed result of the Doppler shift effect(706). The signal receiving parts include antenna for receiving the signals from the signal transmitting parts.

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 position detection through observation of the Doppler shift effect in the robot cleaner system 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, 150a-150c: 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, and at least three transmitters for transmitting a signal of a predetermined different natural frequency; A receiver configured to be movable so as to observe the Doppler shift effect of the received signal while receiving signals from at least three transmitters, each of at least three transmitters based on the Doppler shift effect observed at the receiver And a robot cleaner for acquiring the direction information of and detecting its relative current position based on the direction information of each of the at least three transmitters.

In addition, the above-mentioned receiver further includes an antenna for receiving each signal transmitted from at least three transmitters.

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

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 at least three transmitters are located and to generate direction information by comparing a frequency detected by the frequency detector and 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 a direction in which at least three transmitters are located.

In addition, when observation of the Doppler shift effect is made by moving the above-described antenna along one of the rotating trajectory of the robot cleaner and the rotating trajectory of the rotating body, the angle between the front direction of the robot cleaner and the direction in which at least three transmitters are located is different. It 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.)

In addition, the at least three transmitters described above are configured as first to third transmitters; The first angle between the first transmitter, the robot cleaner, and the second transmitter, and the second angle between the second transmitter, the robot cleaner, and the third transmitter are calculated to consider both the first angle and the second angle. Detect the current position of the robot cleaner.

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, any one of the at least three transmitters described above is installed in the docking station for charging and discharging the foreign matter of the robot cleaner.

In addition, each of the at least three transmitters described above is installed at a predetermined fixed position.

The control method of the robot cleaner system according to the present invention for the above object. Transmitting a signal of a preset natural frequency at each of the at least three transmitters; The robot cleaner receives a signal from at least three transmitters through the receiver; Determine whether a Doppler shift effect is observed at the receiver; Based on the observation of the Doppler shift effect, the direction in which at least three transmitters are located is detected.

The receiver further includes an antenna for receiving signals transmitted from at least three transmitters.

In addition, the above-mentioned receiving unit further includes a rotating body fixed to the antenna, and provided to be rotatable to the robot cleaner; The rotation 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 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 at least three transmitters are located.

이 다음의 수식으로 표현된다.In addition, the angle between the front direction of the robot cleaner and the direction in which at least three transmitters are 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 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.)

In addition, the at least three transmitters described above are configured as first to third transmitters; The first angle between the first transmitter, the robot cleaner, and the second transmitter, and the second angle between the second transmitter, the robot cleaner, and the third transmitter are calculated to consider both the first angle and the second angle. Detect the current position of the robot cleaner.

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. Allow exercise to 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 the four antennas 160a to 160d rotate, the four antennas 160a to 160d also move along the rotational trajectory of the rotating body 160e. 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 it can move the antennas 160a-160d along a predetermined rotational trajectory. In addition, instead of using the rotating body 160e, the entire robot cleaner 100 may be rotated to allow the antennas 160a to 160d to move on the rotating trajectory. 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.

Transmitter 150 for transmitting a radio wave of a predetermined frequency is not limited to being installed only in the docking station 102, a plurality of stations composed of the transmitter and other peripheral circuits, etc. active area of the robot cleaner 100 It can be installed and operated in any number and location within it.

FIG. 2 is a block diagram illustrating a control system of the robot cleaner system illustrated in FIG. 1. As shown in FIG. 2, three transmitters 150a-150c for generating radio waves of a predetermined frequency are installed at predetermined positions in the active area of the robot cleaner 100.

The three transmitters 150a-150c may include a transmitter 150 installed in the docking station 102 as shown in FIG. 1. In the embodiment of the present invention, each transmitter 150a-150c transmits radio waves (or sound waves) of different natural frequencies, and the robot cleaner 100 may transmit different natural frequencies of each transmitter 150a-150c. Through each transmission unit (150a-150c) is distinguished.

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 control unit 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, 214 is electrically connected to enable communication. The frequency detector 204 receives the radio waves of the natural frequencies transmitted from the respective transmitters 150a-150c and detects the frequencies of the received radio waves. Since the antennas 160a-160d of the robot cleaner 100 move on a constant circular orbit, the frequency of the radio waves (Doppler frequency) 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 transmitters 150a to 150c. The direction detecting unit 206 detects the direction of each transmitting unit 150a-150c (that is, the direction of the radio wave transmitting position) based on the frequency detected by the frequency detecting unit 204 and corresponds to each transmitting unit 150a-150c. Direction information is provided to the control unit 214. 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 grasped. 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 in FIG. 1 and is used to move the antennas 160a-160d on a constant rotating trajectory. 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, using the operation characteristics of the robot cleaner 100, the robot cleaner 100 is rotated without using the rotating body 160e of the receiver 160 so that the antennas 160a-160d rotate the robot cleaner 100. It can also be moved in orbit.

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 original 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. The direction of travel of signals (radio waves) transmitted from, for example, 150a.

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 150a travels. 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 direction of travel 308 of the signal (radio wave) transmitted from the transmitter 150a. Move away from bride 150a. 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 antenna 160a at point a, the velocity component of antenna 160a at point c is perpendicular to the direction of travel 308 of the signal (propagation) transmitted from transmitter 150a. Is 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 points a, b, c, and d on the trajectory in which the antennas 160a-160d rotate, but in particular, the maximum decrease and maximum increase in frequency at positions b and d, 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 angles of the antennas 160a-160d with respect to the reference position at point a, the propagation direction of the signal (radio wave) transmitted from the transmitter (for example, 150a) can be determined, so that the antennas 160a-160d The direction of the transmitting unit 150a with respect to) can 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, if one observes the Doppler shift effect by rotating only one antenna, the antenna can be obtained only when the antenna traverses the rotational track to obtain the graph as shown in FIG. 4, 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.

만큼 보정하여 전진함으로써 로봇 청소기(100)가 x축 방향 즉 발신부(150a)를 향해 이동하도록 할 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 transmitter (eg, 150a), and the rotating body 160e of the receiver 160 rotates while the robot cleaner 100 is stopped. As a result, the four antennas 160a-160d also move in the direction of the arrow 504. At this time, at least one of the four antennas 160a-160d moving (for example, 160a) reaches the point a 'past the point a 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. to be. Therefore, when the a 'position is the front of the robot cleaner 100 and the angle θ1 between the point a and the point a' is known, the direction of travel of the robot cleaner 100 is-.

The robot cleaner 100 may move toward the x-axis direction, that is, toward the transmitter 150a by correcting as much as it moves forward.

은 다음의 식 1과 같이 나타낼 수 있다.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 각속도이며, r은 회전체(160e)의 자전 축(506)에서 안테나(160a)까지의 거리이다. 안테나(160a)는 일정한 자전 궤도를 따라 이동하기 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 moves along a constant rotating trajectory, 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 속도이고,

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.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 propagation of the signal 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.

와

의 크기를 검출한다.6 is a view for explaining the position detection through observation of the Doppler shift effect in the robot cleaner system according to an embodiment of the present invention. As shown in FIG. 6, three transmitters 150a-150c are installed at predetermined positions in the region 600 in which the robot cleaner 100 is active, and each transmitter 150a-150c is different from each other. Send out radio waves of frequencies. The robot cleaner 100 receives a radio wave of a natural frequency transmitted from each transmitter 150a-150c by rotating the antennas 160a-160d of the receiver 160, and observes the Doppler shift effect of the received radio wave. By determining the installation direction of each transmitting unit (150a-150c) for the current position of the robot cleaner 100 itself, and from this angle

Wow

Detects the size of

와

의 크기를 구할 수 있으며, 이와 같이 각 발신부(150a-150c)의 방향을 파악하기 위해 상술한 식 1 및 식 2가 이용될 수 있다.That is, the three points a1, a2, and a3 of the antenna (for example, 160a) shown in FIG. 6 have a Doppler shift effect of the radio waves transmitted from each of the three transmitters 150a-150c. These are the locations that correspond to the point. As a result, when the antenna 160a is located at the a1 point, the Doppler shift effect of the radio wave transmitted from the transmitter 150a and received by the antenna 160a is 0, thereby indicating the direction of the transmitter 150a. Using the same principle, it is possible to know the direction of another transmitter 150b when the antenna 160a is located at the point a2, and the direction of the remaining transmitter 150c when the antenna 160a is located at the point a3. Able to know. When the direction information of the three transmitters 150a-150c is obtained, the angle from this is obtained.

Wow

Equation 1 and Equation 2 can be used to determine the direction of each transmitter 150a-150c.

를 구할 수 있으나, 두 개의 발신부(150a, 150b)와 로봇 청소기(100) 사이에 각도

가 형성되는 위치는 구역(600) 내에서 일정한 곡선을 따라 수없이 많이 존재하기 때문에 하나의 각도만으로는 로봇 청소기(100)의 정확한 위치를 알 수 없다. 따라서 하나의 발신기(150c)를 더 추가하여 또 다른 각도

를 구하면, 이와 같이 구해진 각도

와

를 모두 고려하면 각도

를 만족하는 곡선과 각도

를 만족하는 곡선의 단일의 교점이 구해지며, 이 단일의 교점이 곧 로봇 청소기(100)의 현재 위치가 된다. 결론적으로, 서로 다른 위치에 설치되는 적어도 세 개의 발신부(150a-150c)를 이용하면 로봇 청소기(100)의 현재 위치를 정확히 알 수 있다.As such, three transmitters 150a-150c are installed, and each transmitter for the robot cleaner 100 using the Doppler shift effect observed when receiving the radio waves transmitted from the three transmitters 150a-150c. Knowing the directions of 150a-150c may indicate the current position of the robot cleaner 100. That is, if only two transmitters (eg 150a and 150b) are used, the angle

It can be obtained, but the angle between the two transmitters (150a, 150b) and the robot cleaner 100

Since the location is formed a lot of times along the constant curve in the region 600 is not known the exact position of the robot cleaner 100 by only one angle. Therefore, by adding one more transmitter 150c to another angle

If we find, we get this angle

Wow

Considering all the angles

Curve and angle to satisfy

A single intersection point of the curve satisfying is obtained, and this single intersection point becomes the current position of the robot cleaner 100. In conclusion, by using at least three transmitters 150a-150c installed at different positions, the current position of the robot cleaner 100 can be accurately known.

As such, when the current position of the robot cleaner 100 is known, the robot cleaner 100 may be moved to the position of the coordinate by providing the robot cleaner 100 with the coordinates of the destination to which the robot cleaner 100 is to be moved. Can be. To this end, it is preferable that the controller 214 of the robot cleaner 100 has a look-up table that provides coordinate information for each location in the area 600.

와

에 대응되는 좌표 값을 설정해 둠으로써 구현 가능하다. 이후 임의의 좌표가 설정되어 로봇 청소기(100)가 해당 좌표의 위치로 이동해야 하는 경우에는, 해당 좌표에 대응되는 각도

와

를 만족하는 위치로 로봇 청소기(100)가 이동하면 된다.Obtaining the coordinates of an arbitrary position in the zone 600 is an angle at which the robot cleaner 100 varies with the position while moving the entire zone 600 evenly.

Wow

This can be implemented by setting the coordinate value corresponding to. After the arbitrary coordinates are set so that the robot cleaner 100 must move to the position of the coordinates, the angle corresponding to the coordinates

Wow

The robot cleaner 100 may move to a position satisfying the above.

In FIG. 6, in determining different frequencies of radio waves transmitted from each of the three transmitters 150a-150c, the rotational speed of the rotor 160e of the receiver 160 installed in the robot cleaner 100 may be considered. There is a need. Since the robot cleaner 100 distinguishes directions of each of the three transmitters 150a-150e through the frequencies of radio waves received through the receiver 160, the robot cleaner 100 actually observes the antennas 160a-160d of the receiver 160. The bands between the maximum increase value and the maximum decrease value of the frequency do not overlap each other for each radio wave of the transmitters 150a-150c so that the transmitters 150a-150c of the receiver 160 of the robot cleaner 100 can be overlapped with each other. It is possible to determine the direction of each transmitting unit (150a-150c) by distinguishing the unique frequency.

와

를 획득하고(708), 각도

와

를 이용하여 로봇 청소기(100) 자신의 현재 위치를 파악한다(710). 7 is a flowchart illustrating a control method of a robot cleaner system according to an exemplary embodiment of the present invention. Based on this, a method of controlling to move to a destination is illustrated. As shown in FIG. 7, the robot cleaner 100 receives radio waves of different natural frequencies transmitted from the three transmitters 150a-150c while autonomously moving the area to be cleaned or waiting at any arbitrary position. (702). In this case, the robot cleaner 100 rotates the antennas 160a-160d of the receiver 160 to determine its current position and observes the Doppler shift effect on each of the received radio waves (704). The robot cleaner 100 detects the direction of each transmitter 150a-150c by substituting the Doppler shift effect (change of frequency) observed by the receiver 160 into Equations 1 and 2 described above (706). The robot cleaner 100 has an angle as shown in Fig. 6 from the direction information of the transmitters 150a-150c.

Wow

Obtain (708), angle

Wow

Using the robot cleaner 100 to determine its current location (710).

If the robot cleaner 100 needs to move to any position within the zone 600, the robot cleaner 100 moves to the destination based on its current location information and the destination coordinates (712).

The robot cleaner 100 checks whether there is an obstacle on the path to proceed while moving to the destination (714). If it is determined that an obstacle exists on the path to proceed (YES in 714), the obstacle avoidance driving operation is performed (716). In addition, since the direction information toward the destination may be lost in the obstacle avoidance driving process, the flow returns to block 712 to set a new moving direction based on the destination coordinates. If there is no obstacle on the path to proceed (No in 714), the vehicle moves to the destination according to the current direction information, and when the destination arrives, the movement ends (718).

Once you arrive at your destination, you will be able to discharge debris, charge the battery, automate cleaning, and standby mode, depending on your purpose.

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 (16)

At least three transmitters for transmitting signals having different preset natural frequencies; A receiver configured to be movable so as to observe the Doppler shift effect of the received signal while receiving signals from at least three transmitters, and based on the Doppler shift effect observed at the receiver And a robot cleaner for acquiring direction information of each transmitter and detecting a relative current position of the transmitter based on direction information of each of the at least three transmitters. The method of claim 1, wherein the receiving unit, And a antenna for receiving each signal transmitted from the at least three transmitters. The method of claim 2, wherein the receiving unit, The antenna is fixedly installed, and further comprising a rotating body provided to be rotatable to the robot cleaner; Rotation 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 rotating body. The method of claim 2, 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 at least three transmitters are located and to generate 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 4, wherein the direction detecting unit, And a direction in which the antenna indicates when a Doppler shift effect is not observed at a frequency detected by the frequency detector, as a direction in which the at least three transmitters are located. The method of claim 2, When the antenna is moved along one of the rotating trajectory of the robot cleaner and the rotating trajectory of the rotating body to observe the Doppler shift effect, between the front direction of the robot cleaner and the direction in which the at least three transmitters are located. Angle

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 2, The at least three transmitters comprise first to third transmitters; Calculate a first angle between the first transmitter, the robot cleaner, and the second transmitter, and a second angle between the second transmitter, the robot cleaner, and the third transmitter; Robot cleaner system for detecting the current position of the robot cleaner in consideration of the second angle. The method of claim 2, 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, Any one of the at least three transmitter unit is installed in the docking station for charging the robot cleaner and discharge foreign matter. The method of claim 1, And each of the at least three transmitters is installed at a predetermined fixed position. Transmitting a signal of a preset natural frequency at each of the at least three transmitters; The robot cleaner receives a signal from the at least three transmitters through a receiver; Determine whether a Doppler shift effect is observed at the receiver; And controlling the robot cleaner system to detect a direction in which the at least three transmitters are located based on the observation result of the Doppler shift effect. The method of claim 11, wherein the receiving unit, And a antenna for receiving signals from the at least three transmitters. The method of claim 12, wherein the receiving unit, The antenna is fixedly installed, and further comprising a rotating body provided to be rotatable to the robot cleaner; The rotation of the receiver is a control method of the robot cleaner system in which the antenna of the receiver is moved along the rotational trajectory of the rotor by the rotation of the rotating body. The method of claim 12, And a direction in which the antenna indicates when the Doppler shift effect is not observed at the frequency of the signal received at the receiver. The method of claim 12, When the antenna is moved along one of the rotating trajectory of the robot cleaner and the rotating trajectory of the rotating body, the observation of the Doppler shift effect is made between a front direction of the robot cleaner and a direction in which the at least three transmitters are located. Angle

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 12, The at least three transmitters comprise first to third transmitters; Calculate a first angle between the first transmitter, the robot cleaner, and the second transmitter, and a second angle between the second transmitter, the robot cleaner, and the third transmitter; Control method of the robot cleaner system to detect the current position of the robot cleaner in consideration of all the second angle.

Images