CN111031878B

CN111031878B - Autonomous traveling vacuum cleaner and cumulative floor probability updating method

Info

Publication number: CN111031878B
Application number: CN201880052600.9A
Authority: CN
Inventors: 浅井幸治; 前田茂则; 中村智典; 天野克重
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2017-09-07
Filing date: 2018-08-22
Publication date: 2021-05-14
Anticipated expiration: 2038-08-22
Also published as: CN111031878A; WO2019049655A1; JP2019047848A

Abstract

The disclosed device is provided with: a map generation unit (181) that generates a new map using the position of the reference member as a reference position; and a ground probability updating unit (184) that updates the cumulative ground probability of the cumulative map using the ground probability of the new map in each element region whose positions match. A ground probability updating unit (184) adds 1 to the cumulative number of maps that have been used in the update so far in each element region, subtracts the cumulative ground probability from the ground probability, divides the difference by the cumulative number of maps that have been added, and updates the sum of the quotient and the cumulative ground probability as a new cumulative ground probability. Thus, an autonomous traveling cleaner capable of updating a map for coping with environmental changes in a cleaning area is provided.

Description

Autonomous traveling vacuum cleaner and cumulative floor probability updating method

Technical Field

The present invention relates to an autonomous walking vacuum cleaner that generates a map that can show a user an area that has been swept in an autonomous walking manner or the user can specify an area to be swept, and a cumulative floor probability updating method.

Background

In recent years, an autonomous traveling vacuum cleaner has been disclosed: a map of the travel area is created based on the self-position estimation result during the sweep, and the area to be swept next can be specified from the map (see, for example, patent document 1).

The autonomous traveling vacuum cleaner disclosed in patent document 1 first obtains measurement distance information and information from various sensors included in the vacuum cleaner such as a camera and a distance measurement sensor while performing cleaning. Then, the autonomous traveling vacuum cleaner estimates the relative position of the autonomous traveling vacuum cleaner from the movement of the autonomous traveling vacuum cleaner and the positional relationship with the surroundings, using the obtained information. In this way, the autonomous cleaner is configured to grasp where it is located in a room, and create a map that allows the next cleaning area to be freely selected based on the information.

In addition, in the case of an autonomous traveling vacuum cleaner that does not use a sensor for acquiring external information such as a camera, it is not possible to determine at which position on a map the autonomous traveling vacuum cleaner is located at when the cleaning starts. Therefore, an autonomous traveling vacuum cleaner is proposed as follows: when the autonomous vacuum cleaner is not used, the position is determined by waiting while charging the charging stand (see, for example, patent document 2).

The autonomous traveling vacuum cleaner disclosed in patent document 2 records a cleaning history of the autonomous traveling vacuum cleaner, starting from the position of the charging stand. Then, a map is generated based on the recorded information, and the position of the autonomous traveling vacuum cleaner is determined.

However, in practice, many measurement errors are included in the information from the various sensors. Therefore, when an error of a certain level or more occurs, the autonomous traveling vacuum cleaner returns to the starting point, confirms the position again, and corrects the measurement error. In this case, the time to return to the starting point is added to the sweep time. Further, if the user does not make multiple trips to the same location, the error cannot be corrected. Further, even if the cleaning is performed by reciprocating a plurality of times with a starting point such as a charging stand, it is impossible to cope with a change in environment in a cleaning area such as opening and closing of a door, presence or absence of an obstacle, and difference in floor material.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2002-085305

Patent document 2: japanese patent laid-open publication No. 2006-110322

Disclosure of Invention

The invention provides an autonomous traveling vacuum cleaner and a cumulative floor probability updating method, which update a map for coping with environmental changes of a cleaning area based on a map of a traveling area generated each time.

An autonomous traveling vacuum cleaner according to an example of the present invention includes a map generation unit that generates a new map having a position of a reference member provided in a cleaning area as a reference position based on a traveling actual result. The autonomous traveling vacuum cleaner further includes a floor probability updating unit that updates, when 1 element obtained by dividing a new map and an accumulated map obtained by accumulating already-created maps into a plurality of elements at the same position is used as an element region, a cumulative floor probability in each element region having the same position, the floor probability being information indicating whether the new map is a floor included in the new map or not, the cumulative floor probability being information indicating whether the new map is a floor included in the cumulative map or not, using a floor probability. In each element region, the ground probability updating unit adds 1 to the cumulative number of maps that have been used for updating so far, subtracts the cumulative ground probability from the ground probability, divides the difference by the cumulative number of maps that have been added, and updates the sum of the quotient and the cumulative ground probability as a new cumulative ground probability.

In a cumulative ground probability updating method as another example of the present invention, the map generating unit generates a new map having a position of a reference member provided in the sweep area as a reference position based on the walking actual result. When a new map and a cumulative map obtained by accumulating already-created maps are divided into 1 element region having a plurality of obtained elements at the same position, the ground probability updating unit uses, in each element region having the same position, a ground probability indicating whether or not the new map is a ground included in the new map and a cumulative ground probability indicating whether or not the cumulative map is a ground included in the cumulative map. The ground probability updating unit adds 1 to the cumulative number of maps that have been used for updating so far, subtracts the cumulative ground probability from the ground probability, divides the difference by the cumulative number of maps that have been added, and updates the sum of the quotient and the cumulative ground probability as a new cumulative ground probability.

This enables generation of a map with higher accuracy that can cope with changes in the environment in the scanned area and changes in the scanned area itself.

Drawings

Fig. 1 is a plan view showing an appearance of an autonomous walking vacuum cleaner according to embodiment 1.

Fig. 2 is a bottom view showing an external appearance of the autonomous traveling vacuum cleaner.

Fig. 3 is a perspective view showing an external appearance of the autonomous traveling vacuum cleaner.

Fig. 4 is a block diagram showing a functional part related to map creation of the control means in embodiment 1.

Fig. 5 is a diagram showing an example of a new map generated newly in embodiment 1.

Fig. 6 is a diagram showing an example of an old map that has been held in embodiment 1.

Fig. 7 is a diagram showing a state in which a new map generated newly in embodiment 1 is superimposed on an old map already held.

Fig. 8 is a diagram showing an example of a map newly updated and held in embodiment 1.

Fig. 9 is a block diagram showing a functional part related to map creation of the control means in embodiment 2.

Fig. 10 is a plan view showing a sweeping area in embodiment 2.

Fig. 11 is a diagram showing an accumulation map in embodiment 2.

Fig. 12 is a diagram showing a new map in embodiment 2.

Fig. 13 is a diagram showing a state in which the new map and the cumulative map are superimposed so that the reference position is matched and the orientation of the new map is matched with the orientation of the cumulative map in embodiment 2.

Fig. 14 is a diagram showing a state in which the new map and the old map are superimposed so as to minimize the difference in embodiment 2.

Detailed Description

Hereinafter, an embodiment of the autonomous traveling vacuum cleaner according to the present invention will be described with reference to the drawings. The following embodiments merely show an example of the autonomous traveling vacuum cleaner according to the present invention. Therefore, the scope of the present invention is defined by referring to the following embodiments in accordance with the expressions of the claims, and the present invention is not limited to the following embodiments. Therefore, among the constituent elements of the following embodiments, those not described in the independent claims representing the most generic concept of the present invention are not necessarily essential to achieving the object of the present invention, and are described as constituent elements constituting a more preferable embodiment.

The drawings are schematic diagrams in which emphasis, omission, and adjustment of the ratio are appropriately performed in order to illustrate the present invention, and may be different from the actual shape, positional relationship, and ratio.

(embodiment mode 1)

Hereinafter, the configuration of the autonomous traveling vacuum cleaner according to embodiment 1 will be described with reference to fig. 1 to 3.

Fig. 1 is a plan view showing an appearance of an autonomous walking vacuum cleaner according to embodiment 1. Fig. 2 is a bottom view showing an external appearance of the autonomous traveling vacuum cleaner. Fig. 3 is a perspective view showing an external appearance of the autonomous traveling vacuum cleaner. The autonomous traveling vacuum cleaner 100 is a robot-type vacuum cleaner that autonomously travels in a cleaning area, which is a cleaning target area such as a floor surface in a home, and sucks dust present in the cleaning area. For example, the autonomous traveling vacuum cleaner 100 having a planform of a reuleaux triangle is exemplified.

As shown in fig. 1 to 3, the autonomous traveling vacuum cleaner 100 according to embodiment 1 includes a main body 120, a drive unit 130, a cleaning unit 140, a suction unit 150, a control unit 170, and various sensors described below. The main body 120 is used to mount various components of the autonomous vacuum cleaner 100. The driving unit 130 moves the main body 120 within the cleaning region. Sweeping unit 140 collects debris present in the sweeping area. The suction unit 150 sucks the garbage collected by the sweeping unit 140 to the inside of the main body 120. The control unit 170 controls the driving unit 130, the cleaning unit 140, the suction unit 150, and the like.

The main body 120 constitutes a housing for housing the drive unit 130, the control unit 170, and the like. The main body 120 includes a lower body and an upper body, and is configured such that the upper body can be detached from the lower body. The main body 120 includes a damper (damper) provided on an outer peripheral portion thereof so as to be displaceable relative to the main body 120. As shown in fig. 2, the main body 120 has a suction port 121 for sucking garbage into the main body 120.

The drive unit 130 causes the autonomous traveling vacuum cleaner 100 to travel within the cleaning area based on an instruction from the control unit 170. In embodiment 1, 1 drive unit 130 is disposed on each of the left and right sides with respect to the center in the width direction of the main body 120 in a plan view. The number of the driving units 130 is not limited to 2, and may be 1, or 3 or more.

The driving unit 130 includes wheels that travel on the cleaning surface, a traveling motor that applies torque to the wheels, and a housing that houses the traveling motor. The wheels are accommodated in a recess formed in the lower surface of the main body 120 and rotatably attached to the main body 120.

The autonomous traveling vacuum cleaner 100 is configured by a two-wheel drive system having the caster 179 as an auxiliary wheel. By independently controlling the rotation of the 2 wheels, the autonomous traveling vacuum cleaner 100 can freely travel in a straight line, a backward direction, a left turn, a right turn, and the like.

The cleaning unit 140 constitutes a unit for sucking in dust from the suction port 121. Cleaning unit 140 includes a main brush disposed in suction port 121, a brush drive motor for rotating the main brush, and the like.

The suction unit 150 is disposed inside the main body 120. The suction unit 150 includes a fan housing, an electric fan disposed inside the fan housing, and the like. The electric fan sucks air inside the dustbin unit 151 and causes air to be ejected to the outside of the main body 120. Accordingly, the garbage is sucked from the suction port 121 and is stored in the garbage can unit 151.

As described above, the autonomous traveling vacuum cleaner 100 includes various sensors such as the obstacle sensor 173, the distance measuring sensor 174, the collision sensor (not shown), the camera 175, the floor sensor 176, the acceleration sensor (not shown), and the angular velocity sensor (not shown), which are exemplified below.

The obstacle sensor 173 is a sensor that detects an obstacle present in front of the main body 120. In the case of embodiment 1, for example, an ultrasonic sensor is used as the obstacle sensor 173. The obstacle sensor 173 has a transmission unit 171 and a reception unit 172. The transmitter 171 is disposed at the center of the front of the body 120 and transmits the ultrasonic waves forward. The receiving unit 172 is disposed on both sides of the transmitting unit 171, and receives the ultrasonic waves transmitted from the transmitting unit 171. That is, the obstacle sensor 173 receives, by the receiving unit 172, a reflected wave of the ultrasonic wave transmitted from the transmitting unit 171 and reflected by the obstacle. Thus, the obstacle sensor 173 detects the distance and position to the obstacle.

The distance measuring sensor 174 is a sensor that detects a distance between an object such as an obstacle present around the main body 120 and the main body 120. In embodiment 1, the distance measuring sensor 174 is, for example, an infrared sensor having a light emitting section and a light receiving section. That is, the distance measuring sensor 174 measures the distance to the obstacle based on the elapsed time until the infrared ray that has been radiated from the self-light emitting portion and reflected by the obstacle returns to be received by the light receiving portion.

Specifically, the distance measuring sensors 174 are disposed on, for example, the right front top and the left front top. The right-side distance measuring sensor 174 outputs light (infrared rays) toward the right oblique front of the body 120, and the left-side distance measuring sensor 174 outputs light toward the left oblique front of the body 120. With this configuration, when the autonomous walking vacuum cleaner 100 turns, the distance measuring sensor 174 detects the distance between the surrounding object closest to the contour of the main body 120 and the main body 120.

The collision sensor is constituted by, for example, a switch contact displacement sensor, and is provided in a bumper disposed around the body 120. After the obstacle contacts the bumper, the bumper is pressed into the body 120, and thereby the switch contact displacement sensor is turned on. Thereby, the collision sensor detects contact with the obstacle.

The camera 175 is a device that takes an image of the entire circumference of the upper space of the body 120. The image captured by the camera 175 is processed by an image recognition processing unit. By this processing, the current position of the autonomous vacuum cleaner 100 can be grasped from the positions of the feature points in the image.

The floor sensors 176 are disposed at a plurality of positions on the bottom surface of the main body 120, and detect the presence or absence of a floor surface as a cleaning area, for example. In embodiment 1, the floor sensor 176 is, for example, an infrared sensor having a light emitting section and a light receiving section. That is, when the light (infrared ray) radiated from the light emitting portion returns and is received by the light receiving portion, the ground sensor 176 detects that there is a ground. On the other hand, when the receiving unit receives only light of the threshold value or less, the ground sensor 176 detects "no ground".

The drive unit 130 is also provided with an encoder. The encoder detects the rotation angle of each of a pair of wheels rotated by the traveling motor. The traveling amount, turning angle, speed, acceleration, angular velocity, and the like of the autonomous traveling vacuum cleaner 100 are calculated from the information from the encoder.

The acceleration sensor detects acceleration when the autonomous traveling cleaner 100 travels. The angular velocity sensor detects the angular velocity of the autonomous traveling cleaner 100 when turning. Information detected by the acceleration sensor and the angular velocity sensor is used as information for correcting an error caused by the wheel spin, for example.

The obstacle sensor 173, the distance measuring sensor 174, the collision sensor, the camera 175, the ground sensor 176, the encoder, and the like described above are examples of sensors. Therefore, the autonomous traveling vacuum cleaner 100 does not need to have all the sensors. The autonomous traveling vacuum cleaner 100 may further include a sensor of a different type from the above.

The autonomous traveling vacuum cleaner 100 according to embodiment 1 is configured as described above.

Hereinafter, the operation of the functional unit of the control unit 170 will be described with reference to fig. 4.

Fig. 4 is a block diagram showing functional units of the control unit 170 of the autonomous walking vacuum cleaner 100 according to embodiment 1.

As shown in fig. 4, the control unit 170 of the autonomous traveling vacuum cleaner 100 controls the driving unit 130 to cause the autonomous traveling vacuum cleaner 100 to autonomously travel to perform sweeping. The control unit 170 also constitutes a unit that generates a map of a walking area from walking actual results based on information obtained from the various sensors during autonomous walking.

Specifically, the control unit 170 includes a map generation unit 181, a storage device 200, a map comparison unit 182, an extended area determination unit 183, a ground probability update unit 184, and the like.

The map generation unit 181 functions as a processing unit that generates a map of a travel area. That is, the map generation unit 181 generates a map based on the information from the various sensors, for example, using a walking result that is a set of self positions of the autonomous walking vacuum cleaner 100 at a plurality of locations during sweeping obtained by the self position estimation technique.

The map generation unit 181 may generate a map based on the actual result of travel using, as a reference position, the position of a reference member 189 provided in the sweep area 180, which will be described later with reference to fig. 10.

Here, the cleaning region 180 refers to a region where the autonomous vacuum cleaner 100 can travel. That is, the sweep area 180 is generally approximated to the shape of the floor of a room, for example, as shown in fig. 10. In this case, for example, when the partition closed up to now is opened, or when a sofa, a table, or the like originally installed on the floor is removed, the area of the cleaning region 180 may greatly change. Further, the area of the cleaning area 180 may be changed frequently, although slightly, such as a change in the position of a chair or the position of a trash.

The reference member 189 is a member that serves as a reference position when the autonomous traveling vacuum cleaner 100 travels autonomously, and is disposed in the cleaning region 180. The reference member 189 is not particularly limited, but a charging stand or the like that charges a battery provided in the autonomous traveling vacuum cleaner 100 with supplied electric power may be used as the reference member 189.

The actual travel result is, for example, a trajectory of the autonomous traveling vacuum cleaner 100 from when the autonomous traveling vacuum cleaner 100 starts traveling with the reference member 189 as a starting point until when the cleaning is finished, for example, after it is considered that the entire cleaning region 180 has been cleaned. That is, the actual result of the travel may not necessarily be a trajectory when the entire cleaning region 180 is cleaned.

Note that, as the reference member 189, in addition to the above-described charging stand, a portion having a feature extracted from an image captured by the camera 175 shown in fig. 3 or the like may be used as the reference member 189.

The map generating unit 181 generates, as a map, information indicating the outline of the area actually traveled and the reference position 202 shown in fig. 5, which is the position where the reference member 189 shown in fig. 10 is arranged, based on the actual result of the travel of the autonomous traveling vacuum cleaner 100. Then, the map generation unit 181 stores the generated map in the storage device 200 of the control unit 170. At this time, as shown in fig. 10, when an island-shaped region 180A that cannot be moved exists in the scanned region 180, the map generation unit 181 generates a map including information indicating the outer shape and position of the island-shaped region 180A.

In embodiment 1, the map generated by the map generation unit 181 is realized as two-dimensional array data, for example. Specifically, the map generation unit 181 divides the result of the autonomous traveling vacuum cleaner 100 into rectangles having a predetermined size, such as 10cm in vertical and horizontal directions. Then, the map generation unit 181 regards each quadrangle as an element region constituting the arrangement of the map, and stores the element region as arrangement data in the storage device 200. The specific data format to be stored is not particularly limited. The value of each element region is stored as, for example, the ground probability 204, the cumulative ground probability 304, or the like. In addition to the above, the amount of the garbage swept out, the position at which the autonomous traveling vacuum cleaner 100 is stopped, and the like may be stored in the storage device 200 as additional information.

The map comparison unit 182 is a processing unit that extracts all of the continuous element regions as difference regions, which are different from the cumulative land probability 204 of the new map 201 shown in fig. 5 and the cumulative land probability 304 of the cumulative map 301 shown in fig. 6.

Further, a specific method for extracting the difference region is not particularly limited. For example, all the continuous element regions having a difference between the cumulative ground probability 304 and the ground probability 204 equal to or larger than the first threshold may be extracted as the difference region. Then, first, an element region having a probability of a second threshold value or more is extracted from the ground probability 204 of the new map 201 and the cumulative ground probability 304 of the cumulative map 301. Then, of the extracted element regions, all of the continuous element regions in which there is no element region corresponding to the ground probability 204 and the cumulative ground probability 304 may be extracted as the difference region.

The extended region determination unit 183 is a processing unit that determines that the extracted difference region is an extended region when at least one of the following conditions is satisfied. The first condition is the following case: when the area of the difference region in the difference region extracted by the map comparing unit 182 is larger than the third threshold, the maximum depth D (see fig. 7) that is the maximum length of the difference region in the direction intersecting the boundary between the cumulative map 301 and the difference region is larger than the fourth threshold. The second condition is the following case: the maximum length, i.e., the maximum width W, of the difference area in the direction along the boundary line is larger than the fifth threshold value. That is, when at least one of the first condition and the second condition is satisfied, the expanded region determining unit 183 determines the different region satisfying the condition as the expanded region.

Here, the third threshold is not particularly limited, and may be, for example, 1.44 square meters. This corresponds to the size of approximately 1 tatami (japanese: 1 tatamiza) which is a practical value. The fourth threshold and the fifth threshold are not particularly limited, and for example, a numerical value corresponding to the width of the autonomous traveling vacuum cleaner 100 may be used as the fourth threshold and the fifth threshold.

The ground probability updating unit 184 is a processing unit that updates the cumulative ground probability 304, which is information indicating whether the ground included in the cumulative map 301 is a ground surface by a probability, using the ground probability 204 shown below. The ground probability 204 is the following information: when 1 element obtained by dividing the new map 201 and the cumulative map 301 vertically and horizontally at the same position is used as an element region, the information on whether or not the element region is a ground surface included in the new map 201 is represented by a probability in each element region having the same position.

Specifically, the floor probability updating unit 184 first adds 1 to the cumulative number of new maps 201 used in the updating process in each element region. Next, the cumulative ground probability 304 is subtracted from the ground probability 204. Then, the ground probability updating unit 184 divides the difference by the number of accumulated sheets subjected to addition, and updates the sum of the quotient obtained by adding the accumulated ground probability 304 to the quotient to be a new accumulated ground probability 304.

The method of updating the extended area determined by the extended area determination unit 183 is different from the method of updating the cumulative ground probability 304 described above, and will be described later.

The display unit 186 is a processing unit that generates a map for display. The display map is generated based on the updated cumulative map 301 held in the storage device 200. Thus, the map for display can be presented to the user in an easily viewable or easily usable state. In this case, the display unit 186 may have a function of outputting and displaying the generated map for display to, for example, a terminal device owned by the user.

The control unit 170 further includes a storage device 200. The storage device 200 holds a cumulative map 301, and the cumulative map 301 is obtained by accumulating maps generated before the new map 201 is generated by the map generation unit 181. The cumulative map 301 stored in the storage device 200 is associated with a cumulative ground probability 304 indicating with probability whether each coordinate point of the walking area is the ground. The storage device 200 is not particularly limited, and examples thereof include a hard disk and a flash memory.

The functional unit of the control unit 170 is configured and operates as described above.

Hereinafter, the update process of the accumulation map 301 in the control unit 170 is described with reference to fig. 5 to 8.

Fig. 5 is a diagram showing an example of a new map 201 generated newly in embodiment 1 and a ground probability 204 included in the new map 201. Fig. 6 is a diagram showing an example of the cumulative map 301 and the cumulative ground probability 304 included in the cumulative map 301 in embodiment 1. Fig. 7 is a diagram showing an example of a state in which the new map 201 and the cumulative map 301 are superimposed on each other and a comparison between the corresponding ground surface probability 204 and the cumulative ground surface probability 304. Fig. 8 is a diagram showing an example of the updated cumulative map 301 according to embodiment 1.

The upper part of fig. 5 shows a new map 201 newly generated by the map generation unit 181. In addition, the lower part of fig. 5 shows a graph of the ground probability 204 at the section 203 of the new map 201. The map ground probability 204 may take 2 values of 0 (not ground) or 1 (ground) for illustration. The ground probability 204 may be illustrated by taking a value between 0 and 1 based on the reliability of the self-position estimation. In embodiment 1, a new map 201 shown in the upper part of fig. 5 illustrates a portion where the ground probability is 0.5 or more based on the reliability of the self-position estimation.

The new map 201 includes a reference position 202, which is information indicating a start point, in addition to the ground probability 204. The reference position 202 may be a position of a charging stand that functions as the reference member 189 in the autonomous traveling vacuum cleaner 100 shown in fig. 10. Based on information from the sensors, a corner, for example, of a room present in a traveling area where the autonomous traveling vacuum cleaner 100 travels may be set as the reference position 202.

Hereinafter, in embodiment 1, a position corresponding to the charging stand is described as a reference position 202.

The upper part of fig. 6 shows an accumulated map 301 held in the storage device 200 obtained by accumulating maps that have been created. In addition, the lower part of fig. 6 shows a graph of the cumulative ground probability 304 at the section 303 of the cumulative map 301. The accumulation map 301 has an accumulation reference position 302. The accumulated reference position 302 is obtained by accumulating the reference positions 202 included in the new map 201 generated as shown in fig. 5. Specifically, for example, a map is created after daily sweeping, and the history of the created daily map is accumulated (superimposed). The reference position 202 corresponds to, for example, the position of the charging stand. Therefore, even when the new map 201 is generated one or more times, the accumulated reference position 302 is the same position as the reference position 202 in the new map 201 as long as the position of the charging stand does not move. When the charging stand or the like is moved, the accumulated reference position 302 is updated according to a predetermined procedure. Thereby, the latest position of the charging stand becomes the accumulation reference position 302 of the accumulation map 301.

The upper part of fig. 7 shows a diagram of the process of superimposing the new map 201 on the cumulative map 301 in the map comparing unit 182. Specifically, the map comparing unit 182 superimposes the new map 201 and the cumulative map 301 so as to compare them. At this time, the map comparing unit 182 performs the superimposition processing so that the reference position 202 of the new map 201 matches the accumulated reference position 302 of the accumulated map 301, assuming that the position of the reference member 189 in the travel region is not changed. When the position of the reference member 189 is changed, the overlapping process is performed by a reference change checking unit 300 (see fig. 9) described later. In this case, the map comparing unit 182 superimposes the new map 201 on the cumulative map 301 after the processing is executed by the reference change checking unit 300.

The lower part of fig. 7 shows a graph of the ground probability 204 and the cumulative ground probability 304 at a cross section 403 of an upper graph obtained by superimposing the new map 201 on the cumulative map 301. At this time, as shown in the graph, a difference region represented by, for example, the difference a, the difference B, and the difference C is generated in the ground probability 204 and the accumulated ground probability 304 after the superposition. In this case, a region in which the difference between the cumulative land probability 304 of the corresponding part of the cumulative map 301 and the land probability 204 of the new map 201 of the same part is equal to or greater than a first threshold value, such as 0.5 or greater, may be set as the difference region. Further, after the new map 201 and the cumulative map 301 are converted into a map including regions of the new map 201 having the ground probability 204 and the cumulative map 301 having the cumulative ground probability 304 both equal to or higher than a second threshold value, for example, equal to or higher than 0.5, the difference between the two regions in the converted map may be set as a difference region.

The difference is determined by an expanded region determining unit 183 (see fig. 4) that determines whether or not the travel region is expanded. Then, the ground probability updating unit 184 shown in fig. 9 updates the cumulative ground probability of the cumulative map based on the determination result of the expanded area determining unit 183.

The ground probability updating unit 184 offsets the deviation of the ground position due to the self position estimation error or the like by overlapping the new map 201 with the cumulative map 301. This enables the ground surface probability updating unit 184 to improve the probability of accurately determining the ground surface.

For example, with respect to the cumulative map 301 having the cumulative ground probability 304 such as the difference a shown in fig. 7, the ground probability updating unit 184 updates the cumulative ground probability 304 of the cumulative map 301 based on the ground probability 204 of the portion of the newly generated new map 201 corresponding to the difference a.

In the update, the ground probability update unit 184 first averages the data amount accumulated, and corrects the data amount so as to cancel the error. Then, the ground probability updating unit 184 generates the corrected ground probability as update data. At this time, the ground probability updating unit 184 updates the cumulative ground probability by, for example, (expression 1).

[ numerical formula 1]

Here, N (x, y) in (equation 1) is a cumulative number of maps that have been superimposed on the coordinates (x, y) of the cumulative map 301. Mnew (x, y) of (equation 1) is the ground probability 204 at the coordinates (x, y) of the new map 201. P (x, y) of (equation 1) is the cumulative ground probability 304 at the coordinates (x, y) of the cumulative map 301.

Specifically, as shown in (equation 1), the update of the ground probability is performed by first adding 1 to the cumulative number of sheets (N (x, y)) indicating the number of maps used in the update so far. Next, the cumulative ground probability (p (x, y)) is subtracted from the ground probability (Mnew (x, y)). Then, the difference (Mnew (x, y) -p (x, y)) is divided by the number of sheets (N (x, y)) to be added. Next, the cumulative ground probability (p (x, y)) is added to the quotient obtained by the division operation, and the sum is set as a new cumulative ground probability (p (x, y)). Thereby, the ground probability updating unit 184 updates the cumulative ground probability.

As shown in the difference B in fig. 7, when the autonomous vacuum cleaner 100 actually travels in the cleaning area of the difference B to clean a new cleaning area, the cumulative floor probability 304 in the cumulative map 301 is zero or substantially zero. On the other hand, in the new map 201, the land probability 204 of the portion corresponding to the above is 1 or substantially 1. That is, according to the above, the difference region is extracted between the new map 201 and the cumulative map 301.

Therefore, as described above, the extended region determination unit 183 determines that the extracted difference region is an extended region when at least one of the following conditions is satisfied.

The first condition is the following case: when the area of the difference region is larger than the third threshold, the maximum depth D (see the lower part of fig. 7) that is the maximum length of the difference region in the direction intersecting (including being orthogonal to) the boundary 301A between the cumulative map 301 and the difference region is larger than the fourth threshold. The second condition is the following case: the maximum length of the difference region in the direction along the boundary 301A (including parallel), that is, the maximum width W (see the upper part of fig. 7), is larger than the fifth threshold. That is, when at least one or both of the first condition and the second condition are satisfied, the expanded region determination unit 183 determines that the different region satisfying the condition is an expanded region. Thus, the ground probability updating unit 184 updates the cumulative ground probability 304 of the cumulative map 301 shown in fig. 8 to a new cumulative ground probability 304.

A specific update method is performed using, for example, (equation 2) shown below. That is, as shown in (equation 2), the number of accumulated sheets (N (x, y)) of the accumulation map 301 is set to 1 in the expanded area. Then, the cumulative ground probability 304(p (x, y)) of the cumulative map 301 is set to 1.0.

[ numerical formula 2]

Further, as in the difference C shown in fig. 7, when the cumulative map 301 has the cumulative ground probability 304 equal to or higher than a certain value, but the new map 201 has the ground probability 204 of zero or substantially close to zero, the ground probability is not updated. That is, the position indicated by the difference C is determined as a portion where the autonomous traveling vacuum cleaner 100 cannot clean or a portion where an obstacle exists and the autonomous traveling vacuum cleaner cannot travel, and therefore, the floor probability is not updated. In this case, the portion that cannot be cleaned can be separately stored in the storage device 200 as the accumulated information of the non-travel area.

Through the above description, as shown in fig. 8, the result of the update processing of the cumulative map in the control unit 170 is obtained.

Fig. 8 is a diagram showing an example of a map that is updated and held.

The upper part of fig. 8 shows the updated cumulative map 301. The lower part of fig. 8 shows a graph of the updated cumulative ground probability 304 corresponding to the cross section 303 shown in the cumulative map 301.

Thus, based on the cumulative ground probability 304 of the updated cumulative map 301 shown in fig. 8, a position having a cumulative ground probability 304 of, for example, 0.5 or more set as the second threshold value can be plotted as the ground. At this time, the display unit 186 may draw, for example, a wall around the drawn floor surface to generate a map for display. The display unit 186 may transmit the generated map for display to, for example, a mobile terminal owned by the user and display the map. In this case, for example, the control unit or the map screen for display may be provided with a user instruction receiving unit for receiving an instruction. The user instruction receiving unit receives a certain instruction from a user based on the displayed map for display. Specifically, the user designates an area, such as an area to be cleaned next, or a travel area for scheduling. In this case, the user-designated area determination unit may be provided in the control unit, the display map screen, or the like. The user-designated area determination unit has the following functions: the accepted user-specified area is associated with the updated map, and it is determined whether or not the area corresponds to the area that can be cleared.

As described above, according to the autonomous traveling vacuum cleaner 100 and the cumulative floor probability updating method according to embodiment 1, the cumulative floor probability 304 of each element area is calculated in a state where a plurality of maps generated by the map generating unit 181 overlap each other. This improves the accuracy of the map. When the new map 201 is generated, the map generation unit 181 compares the new map 201 with the cumulative map 301 to generate a difference region (difference region). Then, the extended area determination unit 183 determines whether the generated difference region is a new ground or whether an obstacle exists in the generated difference region, based on a predetermined threshold value. This enables more flexible use of the accumulation map 301.

Further, according to the method for updating cumulative ground probability according to embodiment 1, cumulative ground probability 304 corresponding to the extended area can be appropriately updated. This can maintain the entire cumulative map 301 at a high map accuracy.

(embodiment mode 2)

Hereinafter, the autonomous walking vacuum cleaner and the cumulative floor probability updating method in embodiment 2 will be described with reference to fig. 9. In embodiment 2, elements (portions) having the same functions, shapes, mechanisms, and structures as those of embodiment 1 may be given the same reference numerals and their description may be omitted. Note that the following description will be focused on differences from embodiment 1, and descriptions of the same contents may be omitted.

Fig. 9 is a block diagram showing a functional part related to map creation of the control unit 170 in embodiment 2.

That is, as shown in fig. 9, the autonomous walking vacuum cleaner 100 according to embodiment 2 is different from embodiment 1 in that the control unit 170 further includes a reference change confirmation unit 300. The reference change confirmation unit 300 has the following functions: in order to correctly overlap the element regions compared by the map comparing unit 182, the inclination of the new map 201 generated by the map generating unit 181 is matched with the inclination of the cumulative map 301, and the cumulative reference position 302 is updated.

The reference change confirmation unit 300 constitutes a processing unit for updating the accumulated reference position 302 of the accumulated map 301, and includes a longest straight line determination unit 382, a map arrangement unit 383, a difference calculation unit 384, a reference position update unit 385, and the like.

Specifically, the reference change confirmation unit 300 first matches the orientation of the new map 201 generated by the map generation unit 181, such as the inclination, with the accumulated map 301. Then, the reference change confirmation unit 300 confirms whether or not the position of the reference member 189 is changed from the new map 201. At this time, when determining that the position of the reference member 189 has been changed, the reference change confirmation unit 300 functions to update the accumulated reference position 302 of the accumulated map 301.

The autonomous traveling vacuum cleaner 100 according to embodiment 2 is configured as described above.

The operation of the function unit related to map creation of the control unit 170 will be described below with reference to fig. 9 and fig. 10 to 12.

Fig. 10 is a plan view showing the sweep area 180. Fig. 11 is a diagram showing the accumulation map 301. Fig. 12 is a diagram showing a new map 201.

The longest straight line determining unit 382 is a processing unit that determines the longest straight line component among the straight line components included in the map generated by the map generating unit 181. Here, the longest straight line component is the longest line segment included in the periphery of the map among all the line segments included in the map. At this time, when a line segment close to the length of the longest line segment exists within a certain degree of error range, the longest straight line determining unit 382 may determine, as the longest straight line component, a line segment whose component is inclined most closely to the X axis or the Y axis.

Note that the cumulative map 301 and the new map 201 shown in fig. 11 and 12 are generated based on the actual results of the autonomous cleaner 100 walking, as in embodiment 1.

Next, correction of the deviation between the cumulative map 301 and the map of the new map 201 created as described above will be described with reference to fig. 13.

Fig. 13 is a diagram showing a state in which the new map 201 and the accumulated map 301 are superimposed so that the reference position 202 and the accumulated reference position 302 coincide with each other.

First, the map arranging part 383 makes the reference position 202 included in the new map 201 newly generated by the map generating part 181 shown in fig. 12 coincide with the accumulated reference position 302 included in the accumulated map 301 previously generated and accumulated in the storage device 200 shown in fig. 11. Meanwhile, the map arranging section 383 arranges the new map 201 and the cumulative map 301 so as to overlap each other such that the longest straight-line component 193 included in the new map 201 shown in fig. 12 is parallel to or on one straight line with the longest straight-line component 192 included in the cumulative map 301 shown in fig. 11.

Further, processing of superimposing the reference position 202 of the new map 201 on the accumulated map 301 and rotating the new map 201 with respect to the accumulated map 301 centering on the reference position 202 is performed by, for example, affine transformation of a matrix. The affine transformation of the matrix is an example of the process of rotating the map.

Here, the cumulative map 301 shown in fig. 11 is a map obtained by performing statistical processing or the like on a plurality of maps generated in the past. Further, the map initially generated in the cumulative map 301 is arranged such that the longest straight line component is along a predetermined axis (X axis or Y axis). Therefore, the cumulative map 301 and the new map 201 are all generated so that the longest straight line component is along a predetermined axis.

However, in the case of embodiment 2, the new map 201 generated by the map generating unit 181 may be generated in a state where a certain degree of inclination as an error occurs, as shown in fig. 12. Therefore, as shown in fig. 13, the map arranging part 383 is arranged so as to rotate the longest straight-line component 193 of the new map 201 along the Y axis, which is a predetermined axis, with respect to the longest straight-line component 192 of the cumulative map 301. Then, the new map 201 is moved in parallel along the X axis so that the accumulated reference position 302 of the accumulated map 301 matches the reference position 202 of the new map 201. Thus, as described with reference to fig. 14, the difference between the maps is minimized by overlapping the cumulative map 301 and the new map 201 such that the longest straight-line component 192 of the cumulative map 301 is parallel to the longest straight-line component 193 of the new map 201.

Fig. 14 is a diagram showing a state in which the cumulative map 301 and the new map 201 are superimposed so as to minimize the difference.

Specifically, the difference calculation section 384 first moves the new map 201 arranged by the map arrangement unit 383 one or more times in parallel relative to the accumulated map 301. Then, the difference calculation section 384 calculates the difference between the maps each time the parallel translation is performed. Here, the difference between the maps is a portion that does not overlap when the cumulative map 301 and the new map 201 are overlapped. That is, the difference between the maps corresponds to the hatched portion shown in fig. 13.

In embodiment 2, the difference calculation unit 384 moves the new map 201 in parallel with the accumulated map 301 in the X-axis direction and the Y-axis direction in a matrix form 1 or more times at predetermined intervals such as 10 cm. Then, the difference calculation section 384 calculates the difference between the maps at each movement. In this case, the number of times the difference is calculated may be determined uniformly at most any number of times, for example. In addition, when the difference obtained continuously a plurality of times always increases, the calculation of the difference may be ended at this stage.

Next, the reference position update unit 385 updates the reference position of the map to be created next based on the positional relationship of the reference position 202 of the new map 201 with respect to the reference position 202 of the cumulative map 301 when the minimum difference among the differences calculated by the difference calculation unit 384 is obtained. Thus, even when the reference member 189 is moved in the sweep area 180, a new map can be appropriately generated. In fig. 14, the case where the reference position 202 is shifted only in the X-axis direction is illustrated as an example, but the shift of the reference position 202 is not limited to this. The deviation of the reference position 202 is usually caused in at least one of the X axis and the Y axis. Therefore, the reference position update section 385 updates the coordinates of the reference position based on the deviation on the X-axis and the Y-axis. This makes it possible to correct the deviation between the maps with higher accuracy.

As described above, according to the autonomous traveling vacuum cleaner 100 of embodiment 2, even when the new map 201 is generated to be inclined with respect to the cumulative map 301 due to measurement errors of various sensors or the like, the inclination can be corrected so that the new map 201 and the cumulative map 301 accurately overlap each other. This can improve the accuracy of the cumulative ground probability 304 to be updated.

In addition, according to the autonomous traveling vacuum cleaner 100 of embodiment 2, when the reference member 189 moves in the cleaning region 180, the autonomous traveling vacuum cleaner 100 recognizes the movement of the reference member 189. Then, the accumulated reference position 302 is correctly updated based on the recognized movement of the reference member 189. Therefore, the accuracy of the cumulative ground probability 304 can be maintained in a high state.

The present invention is not limited to the above embodiments. For example, it is possible to arbitrarily combine the components described in the present specification, and to set another embodiment, which is realized by excluding some of the components, as an embodiment of the present invention. Further, a modification example in which various modifications that may occur to those skilled in the art are implemented to the above-described embodiment within a scope not departing from the gist of the present invention and a meaning indicated by a description in the claims is also included in the present invention.

For example, in the configurations described in embodiment 1 and embodiment 2, the map generation unit 181 may be configured as a computer (computer) such as a server connected to the autonomous vacuum cleaner 100 via a network. In this case, the cleaner system can be regarded as a cleaner system including the autonomous traveling cleaner 100. At this time, the new map 201 generated by the map generation unit 181 is transmitted to the computer via the network. Then, the accumulated map 301 held by the computer is updated based on the transmitted new map 201.

Further, the following configuration may be adopted: the user can confirm the result of sweeping on the terminal such as a smartphone based on the cumulative map 301 received from the computer.

Further, the user may be configured to be able to specify an area to be cleaned by the autonomous vacuum cleaner 100 via the mobile terminal.

Industrial applicability

The present invention is applicable to a so-called robot type vacuum cleaner that autonomously travels and cleans in homes, factories, large-scale facilities, and the like.

Description of the reference numerals

100: an autonomous traveling vacuum cleaner; 120: a main body; 121: a suction inlet; 130: a drive unit; 140: a cleaning unit; 150: a suction unit; 151: a tank unit; 170: a control unit; 171: a transmission unit; 172: a receiving section; 173: an obstacle sensor; 174: a ranging sensor; 175: a camera; 176: a ground sensor; 179: a caster wheel; 180: sweeping the area; 180A: a field; 181: a map generation unit; 182: a map comparing section; 183: an extended area determination unit; 184: a ground probability updating unit; 186: a display unit; 189: a reference member; 192. 193: the longest straight line component; 200: a storage device; 201: a new map; 202: a reference position; 203. 303, 403: a section; 204: ground probability; 300: a reference change confirmation unit; 301: accumulating the map; 301A: a boundary line; 302: accumulating the reference positions; 304: accumulating the ground probability; 382: a longest straight line determining section; 383: a map configuration section; 384: a difference calculation unit; 385: a reference position update unit.

Claims

1. An autonomous traveling cleaner that autonomously travels to perform cleaning, the autonomous traveling cleaner comprising:

a map generation unit that generates a new map having a position of a reference member provided in the sweep area as a reference position, based on the actual result of the travel; and

a ground probability updating unit that updates, when 1 element obtained by dividing the new map and a cumulative map obtained by accumulating already-created maps into a plurality of element regions at the same position is used as an element region, a cumulative ground probability that is information indicating whether or not the new map and the cumulative map are ground surfaces included in the cumulative map by using a ground probability that is information indicating whether or not the new map and the cumulative map are ground surfaces included in the cumulative map, in each of the element regions having the same position,

in each of the element regions, the ground probability updating unit adds 1 to a cumulative number of pieces indicating the number of maps used in updating so far, subtracts the cumulative ground probability from the ground probability, divides the difference by the cumulative number of pieces obtained by addition, and updates the sum obtained by adding the cumulative ground probability to the quotient to be the new cumulative ground probability.

2. The autonomous walking vacuum cleaner of claim 1,

the map comparison unit extracts all of the continuous element regions as difference regions, the element regions having different ground probabilities from the cumulative ground probabilities of the cumulative map.

3. The autonomous walking vacuum cleaner of claim 2,

the map comparing unit extracts all of the continuous element regions having a difference between the cumulative ground probability and the ground probability of a first threshold value or more as the difference region.

4. The autonomous walking vacuum cleaner of claim 2,

the map comparison unit extracts the element regions having a probability of a second threshold or higher from the ground probability of the new map and the cumulative ground probability of the cumulative map, and extracts all of the continuous element regions having no mutually corresponding element regions as the difference regions.

5. The autonomous walking vacuum cleaner of any one of claims 2 to 4,

the map comparison unit extracts a difference area from the difference area extracted by the map comparison unit, and the difference area is determined to be an extended area by the extended area determination unit, the difference area satisfying at least one of the following two conditions: a case where, when the area of the difference region is larger than a third threshold value, the maximum length of the difference region in a direction intersecting a boundary line between the cumulative map and the difference region, that is, the maximum depth, is larger than a fourth threshold value; and a case where a maximum length, i.e., a maximum width, of the difference region in a direction along the boundary line is larger than a fifth threshold value when an area of the difference region is larger than the third threshold value,

the ground surface probability updating unit sets the cumulative number of pieces of the extended area determined by the extended area determining unit to 1, sets the cumulative ground surface probability to 1, or matches the cumulative ground surface probability with the ground surface probability of the new map.

6. The autonomous walking vacuum cleaner according to any one of claims 1 to 4, further comprising:

a longest straight line determining unit that determines a longest straight line component among straight line components included in the new map generated by the map generating unit;

a map arranging unit that aligns the reference position included in the new map with an accumulated reference position included in the accumulated map, and arranges the longest straight-line component included in the new map and the longest straight-line component included in the accumulated map in parallel or on a straight line;

a difference calculation unit that moves the new map arranged by the map arrangement unit in parallel relative to the cumulative map more than once, and calculates a difference between the new map and the cumulative map at each movement; and

a reference position updating unit that updates the accumulated reference position based on a positional relationship of the reference position of the new map with respect to the accumulated reference position of the accumulated map when the difference that is the smallest of the differences calculated by the difference calculating unit is obtained.

7. The autonomous walking vacuum cleaner according to claim 5, further comprising:

8. A cumulative ground probability updating method in an autonomous traveling cleaner which autonomously travels to perform cleaning, includes the following steps,

a map generation unit that generates a new map having a position of a reference member provided in the sweep area as a reference position, based on the actual result of the travel;

when 1 element obtained by dividing the new map and a cumulative map obtained by accumulating already-created maps into a plurality of element regions at the same position is used as an element region, a ground probability updating unit uses, in each of the element regions having the same position, a ground probability that is information indicating whether or not the new map is a ground included in the new map and a cumulative ground probability that is information indicating whether or not the cumulative map is a ground included in the cumulative map; and

the ground surface probability updating unit adds 1 to a cumulative number of pieces indicating the number of maps used in updating so far, subtracts the cumulative ground surface probability from the ground surface probability, divides the difference by the cumulative number of pieces obtained by addition, and updates the sum obtained by adding the cumulative ground surface probability to the quotient to be the new cumulative ground surface probability.