JP2006323618A - Self-propelled robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect obstacles in a self-propelled robot's surroundings. <P>SOLUTION: For the self-propelled robot, three ultrasonic transmitters and four ultrasonic receivers are disposed alternately and equidistantly in the traveling direction V1 by centering the ultrasonic transmitter s2. Here, the ultrasonic receiver r1, ultrasonic transmitter s1, ultrasonic receiver r2, ultrasonic transmitter s2, ultrasonic receiver r3, ultrasonic transmitter s3 and ultrasonic receiver r4 are disposed one by one from the left side of the traveling direction V1. Along the center line LS in parallel with the traveling direction V1 through the central point O of the body 10, three ultrasonic transmitters and four receivers are disposed at the axisymmetrical positions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a self-propelled robot that includes a drive unit that rotates a drive shaft of at least one wheel at a predetermined rotational speed, and a steering unit that freely sets a traveling direction, and travels within a predetermined region. is there.

  In recent years, a self-propelled robot that travels substantially uniformly in a predetermined area, such as a cleaning robot that cleans an indoor floor surface, is known. Here, in order to make the self-propelled robot run substantially uniformly within a predetermined area, it is necessary to accurately detect an obstacle in the traveling direction of the self-propelled robot, and a method for detecting this obstacle Various proposals have been made.

For example, in Patent Literature 1, four transmission ultrasonic sensors and five reception ultrasonic sensors are alternately arranged, and one transmission ultrasonic sensor and two adjacent reception ultrasonic sensors are provided. An obstacle detection device is disclosed that detects obstacles over a wide range of front and left and right by performing obstacle detection by sequentially switching the combination at regular time intervals and performing obstacle detection. .
JP 2003-35774 A

  However, in the obstacle detection device disclosed in Patent Document 1, an obstacle in front of the front is detected from two transmitting ultrasonic sensors (transmitting ultrasonic sensors S2 and S3 in FIG. 5 of Patent Document 1). Therefore, it is difficult to measure obstacles in front of the front with two receiving ultrasonic sensors at the same time, and the detection accuracy of obstacles in front of the front may not be sufficient. .

  In other words, the self-propelled robot needs to detect an obstacle while moving within a predetermined area. However, if the timing for detecting the obstacle is different, the self-propelled robot moves during that time. A measurement error corresponding to this occurs.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a self-propelled robot capable of accurately detecting surrounding obstacles.

  The self-propelled robot according to claim 1 includes a driving unit that rotates a driving shaft of at least one wheel at a predetermined rotational speed, and a steering unit that freely sets a traveling direction, and travels within a predetermined region. A self-propelled robot that is arranged in the vicinity of a center line that is a straight line that passes through the center of the self-propelled robot body and is parallel to the traveling direction, and transmits a signal toward the traveling direction of the self-propelled robot. 1 transmitting means, a signal transmitted by the first transmitting means, a first receiving means for receiving a reflected signal reflected at an outer edge of the predetermined area, and a signal transmitted by the first transmitting means Distance calculating means for obtaining a distance between the self-propelled robot and an outer edge of the predetermined area using an elapsed time until it is received by the first receiving means; and Arranged on both sides of the center line It is characterized in that it is.

  According to the above configuration, the signal is directed toward the traveling direction of the self-propelled robot by the first transmitting means disposed in the vicinity of the center line that is a straight line passing through the center of the self-propelled robot body and parallel to the traveling direction. Is transmitted, and a reflected signal reflected by the outer edge of a predetermined region is received by the first receiving means. Then, the distance calculating means obtains the distance between the self-propelled robot and the outer edge of the predetermined region using the elapsed time until the signal transmitted by the first transmitting means is received by the first receiving means. It is done. Here, the first receiving means is disposed on both sides of a center line that is a straight line passing through the center of the self-propelled robot body and parallel to the traveling direction.

  Therefore, a signal is transmitted toward the traveling direction of the self-propelled robot by the first transmission means disposed near the center line, and the first transmission is performed by the first reception means disposed on both sides of the center line. The signal transmitted by the means, and the reflected signal reflected at the outer edge of the predetermined region is received, so that at least two directions of the front front using the signal transmitted by the first transmitting means at one timing, The distance between the self-propelled robot and the outer edge of the predetermined area is obtained, and the obstacle in front of the front is accurately detected.

  The self-propelled robot according to a second aspect is characterized in that the first receiving means is disposed at a position substantially line symmetrical with respect to the center line.

  According to the above configuration, since the first receiving means is disposed at a position substantially symmetrical with respect to the center line that is a straight line that passes through the center of the self-propelled robot body and is parallel to the traveling direction, The distance between the self-propelled robot and the outer edge of the predetermined area is determined in at least two directions in front of the front using the signal transmitted by the first transmission means at the timing, and the obstacle in front of the front is more accurately Detected.

  The self-propelled robot according to claim 3 is characterized in that only one first receiving means is provided on each side of the center line.

  According to the above configuration, only one first receiving means is provided on each side of the center line that is a straight line passing through the center of the self-propelled robot body and parallel to the traveling direction. Obstacles in front of the front are accurately detected.

  5. The self-propelled robot according to claim 4, wherein the second transmission means is disposed at a position substantially line symmetrical with respect to the center line, and transmits a signal in a direction away from the center line, and the second transmission. And a second receiving means for receiving a reflected signal reflected at the outer edge of the predetermined area, and the distance calculating means is configured to receive the signal sent by the second transmitting means. The distance between the self-propelled robot and the outer edge of the predetermined area is obtained using the elapsed time until it is received by the second receiving means.

  According to said structure, a signal is transmitted in the direction away from a centerline by the 2nd transmission means arrange | positioned in the substantially line symmetrical position with respect to a centerline, and a 2nd transmission means is transmitted by the 2nd reception means. The reflected signal reflected at the outer edge of the predetermined area is received. Then, the distance calculating means obtains the distance between the self-propelled robot and the outer edge of the predetermined area using the elapsed time until the signal transmitted by the second transmitting means is received by the second receiving means. It is done.

  Therefore, a self-propelled robot is used by using the elapsed time until a signal is transmitted in a direction away from the center line by the second transmitter and the reflected signal reflected at the outer edge of the predetermined area is received by the second receiver. The distance between the self-propelled robot in the direction away from the center line and the outer edge of the predetermined area is detected. That is, the distance between the self-propelled robot and the outer edge of the predetermined region in the left-right direction (both left and right) with respect to the traveling direction is detected.

  The self-propelled robot according to claim 5 is characterized in that only one second transmitting means is disposed at a position substantially line symmetrical with respect to the center line.

  According to said structure, since only one 2nd transmission means is each arrange | positioned in the substantially line symmetrical position with respect to a center line, it is a simple structure and is self-propelled in the direction away from a center line. A distance between the robot and the outer edge of the predetermined area is detected.

  The self-propelled robot according to claim 6 is characterized in that the first transmission means and the second transmission means sequentially transmit in a preset order.

  According to said structure, since a 1st transmission means and a 2nd transmission means are sequentially transmitted in the order set beforehand, it is self-propelled about the front front of the advancing direction, and the left-right direction with respect to the advancing direction. The distance between the robot and the outer edge of the predetermined area is sequentially detected, and proper detection is performed.

  8. The self-propelled robot according to claim 7, wherein the self-propelled robot travels along the outer edge of the predetermined area, detecting means for detecting a distance or a minimum value of a plurality of distances obtained by the distance calculating means as a separation distance. A first driving means for instructing the steering means to travel in order to travel in the first mode, which is a control mode, and a control mode in which the vehicle travels repeatedly in a straight line and rotation in the region. In order to travel in the two modes, the vehicle travels straight until the separation distance is equal to or less than a predetermined value set in advance, and when the separation distance is equal to or less than a predetermined value set in advance, A second traveling means for changing the traveling direction to a predetermined direction; a straight traveling time measuring means for measuring a straight traveling time that is a time from the start to the stop of the straight traveling while traveling in the second mode; and two or more places A straight running time storage means for storing the straight running time for the number of times; and a switching means for switching between the first mode and the second mode, wherein the switching means satisfies a predetermined condition for the straight running time for the predetermined number of times. When the condition is satisfied, the second mode is switched to the first mode.

  According to said structure, the minimum value of 1 distance or several distance calculated | required by the distance calculation means is detected by a detection means as a separation distance. Then, the first traveling means instructs the steering means to travel in the first mode, which is a control mode for traveling along the outer edge of the predetermined region, and the second traveling means performs the predetermined direction. In order to travel in the second mode, which is a control mode in which the vehicle travels in a straight line and rotates repeatedly, the vehicle travels straight until the separation distance is equal to or less than a predetermined value, and the separation distance is preset. When it is equal to or less than the predetermined value, the straight traveling is stopped and the traveling direction is changed to a predetermined direction with respect to the steering means. The straight travel time measuring means measures the straight travel time that is the time from the start of the straight travel during the second mode to the stop, and stores the straight travel time for two or more predetermined times in the straight travel time storage means. Is done. Further, the second mode is switched to the first mode when the straight traveling time for a predetermined number of times satisfies a predetermined condition by the switching means.

  Accordingly, during traveling in the second mode, which is a control mode in which the vehicle travels repeatedly within a predetermined area, the straight traveling time that is the time from the start of the straight traveling for two or more predetermined times to the stop is predetermined. When the condition is satisfied, the control mode is switched from the second mode to the first mode, which is a control mode for running along the outer edge of the predetermined area, so that the outer edge in the predetermined area has a complicated shape. Even so, the mode is switched to the first mode at an appropriate frequency, and the vehicle can travel substantially uniformly within a predetermined area.

  According to the first aspect of the present invention, a signal is transmitted toward the traveling direction of the self-propelled robot by the first transmission means disposed in the vicinity of the center line, and disposed on both sides of the center line. Since the first receiving means receives the signal transmitted from the first transmitting means and reflected at the outer edge of the predetermined area, the signal transmitted from the first transmitting means at one timing is used. Thus, the distance between the self-propelled robot and the outer edge of the predetermined area is determined in at least two directions in front of the front, and an obstacle in front of the front can be accurately detected.

  According to the second aspect of the present invention, the first receiving means is disposed at a substantially line-symmetrical position with respect to a center line that is a straight line passing through the center of the self-propelled robot body and parallel to the traveling direction. Therefore, the distance between the self-propelled robot and the outer edge of the predetermined area is obtained in at least two directions in front of the front using the signal transmitted by the first transmission means at one timing, and the obstacle in front of the front Can be detected more accurately.

  According to the invention described in claim 3, since only one first receiving means is disposed on each side of the center line that is a straight line that passes through the center of the self-propelled robot body and is parallel to the traveling direction, With a simple configuration, obstacles in front of the front can be accurately detected.

  According to the fourth aspect of the present invention, the signal is transmitted in the direction away from the center line by the second transmitting means, and the reflected signal reflected at the outer edge of the predetermined area is received by the second receiving means. Since the distance between the self-propelled robot and the outer edge of the predetermined area is obtained using time, the distance between the self-propelled robot in the direction away from the center line and the outer edge of the predetermined area can be detected. . That is, it is possible to detect the distance between the self-propelled robot and the outer edge of the predetermined region in the left and right direction (both left and right) with respect to the traveling direction.

  According to the fifth aspect of the present invention, since only one second transmitting means is disposed at a substantially line symmetrical position with respect to the center line, the direction away from the center line is simple. The distance between the self-propelled robot and the outer edge of the predetermined area can be detected.

  According to invention of Claim 6, since a 1st transmission means and a 2nd transmission means are sequentially transmitted in the order set beforehand, regarding the front front of the advancing direction, and the left-right direction with respect to the advancing direction The distance between the self-propelled robot and the outer edge of the predetermined area is sequentially detected, and can be detected appropriately.

  According to the seventh aspect of the present invention, the vehicle travels in a second mode, which is a control mode in which the vehicle travels repeatedly in a predetermined region by repeating straight travel and rotation, and from straight travel start to stop for two or more predetermined times. When the straight traveling time that is the time of the vehicle satisfies the predetermined condition, the control mode is switched from the second mode to the first mode that is a control mode for traveling along the outer edge of the predetermined region. Even in the case where the outer edge has a complicated shape, the mode is switched to the first mode at an appropriate frequency, and the vehicle can travel substantially uniformly in a predetermined area.

  1 and 2 are a bottom view and a perspective view, respectively, showing an example of a cleaning robot (corresponding to a self-propelled robot) according to the present invention. Here, a cleaning robot that collects dust on the floor of a room (corresponding to a predetermined area) will be described. The cleaning robot 1 includes a main body 10 configured in a substantially cylindrical shape, a driving unit 11 (corresponding to a driving means and a steering means) that causes the main body 10 to travel with respect to a floor surface, and a wall surface (or an obstacle). A distance sensor 12 (corresponding to a part of the first transmitting means, a part of the second transmitting means, a part of the first receiving means and a part of the second receiving means) and a wall surface (or A bumper 13 that detects contact with an obstacle), a dust collecting part 14 that collects dust on the floor, an auxiliary wheel 15 that supports the main body 10 substantially parallel to the floor, and a wall surface (or an obstacle). 3) A side brush 16 that moves the dust in the vicinity to the main body 10 side and a control unit 17 (not shown: see FIG. 3) that controls the operation of the entire cleaning robot 1 are provided.

  The drive unit 11 includes drive wheels 111a and 111b that are rotatably supported at substantially both end positions of the main body 10 in a direction perpendicular to the traveling direction V1, and motors 113a and 113b that respectively drive the drive wheels 111a and 111b. , Reduction gears 112a and 112b that reduce the rotational speed of the motors 113a and 113b and transmit them to the drive wheels 111a and 111b, respectively. In addition, encoders 115a and 115b that detect the rotational speeds of the motors 113a and 113b are disposed at appropriate positions of the motors 113a and 113b (not shown).

  The distance sensor 12 is an ultrasonic sensor, and includes three ultrasonic transmitters 121 (corresponding to a part of the first transmitting unit and a part of the second transmitting unit) and four ultrasonic receivers 122. (Corresponding to a part of the first receiving means and a part of the second receiving means) are alternately embedded in the bumper 13 at substantially equal intervals. The ultrasonic waves transmitted from the three ultrasonic transmitters 121 are received by the two adjacent ultrasonic receivers 122, and the ultrasonic receiver 122 starts the transmission of the ultrasonic signal by the ultrasonic transmitter 121. The distance from the wall surface (or obstacle) is detected based on the time until reception of the ultrasonic signal starts.

  The bumper 13 is formed in a semi-cylindrical shape along the traveling direction V1 side of the main body 10, and detects contact with a wall surface (or an obstacle) by a touch sensor 131 (not shown).

  The dust collection unit 14 is disposed to face the floor surface, and is provided with a dust collection port 141 through which dust on the floor surface is sucked, a dust collection box 142 that stores dust from the dust collection port 141, and a dust collection port. In order to suck in dust from 141, a fan 143 that makes the dust collection box 142 a negative pressure is provided.

  The auxiliary wheel 15 is rotatably supported on the bottom surface of the main body 10 so as to support the bottom surface of the main body 10 substantially parallel to the floor surface, and one auxiliary wheel 15 is provided on each of the front side and the rear side in the traveling direction V1. And only two are arranged.

  The side brush 16 moves the dust near the wall surface (or obstacle) from the dust collection port 141 to a position where it can be sucked. That is, as will be described later with reference to FIG. 4 (a), when traveling along the wall, it is separated from the wall surface (or obstacle) to the left side with respect to the traveling direction V1 by a predetermined distance (for example, 20 mm). In order to run, it is necessary to move the dust near the wall surface (or obstacle) by the side brush 16 from the dust collection port 141 to a position where it can be sucked.

  FIG. 3 is a configuration diagram illustrating an example of a main part of the cleaning robot 1. The control unit 17 includes a CPU (Central Processing Unit) 171 that performs various processes and a RAM (Random Access Memory) 172 that stores various data.

  The CPU 171 functionally transmits a signal in the left-right direction with respect to the traveling direction, and a first transmitting unit 171a (corresponding to a part of the first transmitting means) that transmits a signal toward the traveling direction of the cleaning robot 1. A second transmitter 171b (corresponding to a part of the second transmitter) and a first receiver 171c (corresponding to a part of the first receiver) for receiving a signal transmitted by the first transmitter 171a And a second receiving unit 171d (corresponding to a part of the second receiving means) that receives a signal transmitted by the second transmitting unit 171b, and a wall surface (or, using an elapsed time from the transmitting time to the receiving time) A distance calculation unit 171e for obtaining a distance from the obstacle) (corresponding to a distance calculation unit) is provided.

  In addition, the CPU 171 functionally includes a detection unit 171f (corresponding to detection means) that detects a separation distance that is the minimum value of one distance or a plurality of distances obtained by the distance calculation unit 171e, and a wall surface (or In order to travel in the along-wall mode (corresponding to the first mode), which is a control mode for traveling along the obstacles, the along-wall traveling unit 171g (indicating the traveling direction to the motors 113a and 113b) And the separation distance is equal to or less than a predetermined value set in advance so that the vehicle travels in a random mode (corresponding to the second mode), which is a control mode in which the vehicle travels in a straight line and rotates repeatedly. When the separation distance is less than or equal to a predetermined value, the straight travel is stopped and the motors 113a and 113b are caused to change the traveling direction to a predetermined direction. And a dam driving unit 171h (corresponding to the second driving means).

  Further, the CPU 171 functionally includes a straight traveling time measuring unit 171i (corresponding to a straight traveling time measuring means) that measures a straight traveling time that is a time from the start of straight traveling while stopping in a random mode, and a wall-side mode. A switching unit 171j (corresponding to switching means) for switching between the random mode and the random mode, and a prohibiting unit 171k for prohibiting the operation of the switching unit 171j when the traveling time in the random mode has not reached a predetermined time set in advance. And a cleaner control unit 171m that performs control related to dust collection. The RAM 172 functionally includes a straight traveling time storage unit 172a (corresponding to a straight traveling time storage unit) that stores straight traveling time for two or more predetermined times (here, three times).

  Based on an instruction from the detection unit 171f, the first transmission unit 171a performs ultrasonic transmission 121 (on the center line LS illustrated in FIG. 4 on the center line LS only for a predetermined transmission time Ts2 illustrated in FIG. 4B). An ultrasonic signal having a predetermined divergence angle θs (see FIG. 5) is transmitted to the traveling direction of the cleaning robot 1 via the sound wave transmitter s2).

  The second transmitter 171b is arranged on the left side with respect to the ultrasonic transmitter 121 (center line LS shown in FIG. 4) for a predetermined transmission time Ts1 shown in FIG. 4B based on an instruction from the detector 171f. The ultrasonic signal having a predetermined divergence angle θs (see FIG. 5) is transmitted to the left with respect to the traveling direction of the cleaning robot 1 via the ultrasonic transmitter s1). Further, the second transmitter 171b is positioned on the right side with respect to the ultrasonic transmitter 121 (center line LS shown in FIG. 4) for a predetermined transmission time Ts3 shown in FIG. 4B based on an instruction from the detector 171f. An ultrasonic signal having a predetermined divergence angle θs (see FIG. 5) is transmitted to the right with respect to the traveling direction of the cleaning robot 1 via the disposed ultrasonic transmitter s3).

  The first receiving unit 171c is transmitted through the ultrasonic transmitter s2 by the first transmitting unit 171a, and can receive an angle θr (see FIG. 5) among the reflected signals reflected by the wall surface (or obstacle). The reflected signal in the signal is transmitted through the ultrasonic receiver 122 (ultrasonic receivers r2 and r3 disposed on the left and right of the center line LS shown in FIG. 4) based on an instruction from the detection unit 171f in FIG. It is received only for the predetermined reception time Tr2 shown in b).

  The second receiving unit 171d transmits an angle θr (see FIG. 5) that can be received from the reflected signal that is transmitted from the second transmitting unit 171b via the ultrasonic transmitter s1 and reflected by the wall surface (or obstacle). The reflected signal in the signal is transmitted through the ultrasonic receiver 122 (ultrasonic receivers r1 and r2 disposed on the left side of the center line LS shown in FIG. 4) based on an instruction from the detection unit 171f. It is received only for the predetermined reception time Tr1 shown in b). In addition, the second receiving unit 171d transmits the angle θr (FIG. 5) that can be received among the reflected signals that are transmitted by the second transmitting unit 171b via the ultrasonic transmitter s3 and reflected by the wall surface (or obstacle). The reflected signal in FIG. 4 is transmitted via the ultrasonic receiver 122 (ultrasonic receivers r3 and r4 disposed on the right side of the center line LS shown in FIG. 4) based on an instruction from the detection unit 171f. The signal is received only for a predetermined reception time Tr3 shown in 4 (b).

  The distance calculation unit 171e obtains the distance from the wall surface (or obstacle) using the elapsed time from the transmission time by the first transmission unit 171a to the reception time by the first reception unit 171c, and by the second transmission unit 171b. The distance from the wall surface (or obstacle) is obtained using the elapsed time from the transmission time to the reception time by the second reception unit 171d.

  Specifically, the distance calculation unit 171e uses the elapsed time from the transmission time from the ultrasonic transmitter s2 by the first transmission unit 171a to the reception time at the ultrasonic receivers r2 and r3 by the first reception unit 171c. Thus, the distance to the wall surface (or obstacle) in front of the traveling direction is obtained.

  Further, the distance calculation unit 171e uses the elapsed time from the transmission time from the ultrasonic transmitter s1 by the second transmission unit 171b to the reception time at the ultrasonic receivers r1 and r2 by the second reception unit 171d. While obtaining distances L11 and L12 (see FIG. 5) with the left wall surface (or obstacle), the ultrasonic receiver by the second receiver 171d from the transmission time from the ultrasonic transmitter s3 by the second transmitter 171b The distance from the wall surface (or obstacle) on the right side in the traveling direction is obtained using the elapsed time up to the reception time at r3 and r4.

  The detection unit 171f includes a first transmission unit 171a, a second transmission unit 171b, and a first reception unit 171c via three ultrasonic transmitters 121 and four ultrasonic receivers 122 disposed in the bumper 13. The instruction information is output to the second receiving unit 171d, and the minimum value of one distance or a plurality of distances detected by the distance calculating unit 171e is detected as the separation distance. Hereinafter, this will be specifically described with reference to FIG. FIG. 4 is an explanatory diagram illustrating an example of the operation of the detection unit 171f.

  (A) is a top view which shows the relationship between the arrangement | positioning of a sensor and the distance detected, (b) shows the operation timing of the three ultrasonic transmitters 121 and the four ultrasonic receivers 122. FIG. It is a timing chart which shows. As shown in (a), three ultrasonic transmitters 121 and four ultrasonic waves are equally spaced with respect to the traveling direction V1 with the ultrasonic transmitter s2 as the center (tip position in the traveling direction V1). Receivers 122 are arranged alternately. Here, from the left side in the traveling direction V1, the ultrasonic receiver r1, the ultrasonic transmitter s1, the ultrasonic receiver r2, the ultrasonic transmitter s2, the ultrasonic receiver r3, the ultrasonic transmitter s3, the ultrasonic wave Assume that the receivers r4 are arranged in this order.

  Here, the three ultrasonic transmitters 121 and the four ultrasonic receivers 122 are line-symmetric with respect to the center line LS that is a straight line that passes through the center point O of the main body 10 and is parallel to the traveling direction V1. Are arranged at various positions. Specifically, for example, the ultrasonic transmitter s1 and the ultrasonic transmitter s3 are arranged at positions symmetrical with respect to the center line LS, and the ultrasonic receiver r1 and the ultrasonic receiver r4 are center lines. It is disposed at a position symmetrical with respect to LS.

  Here, the cleaning robot 1 demonstrates the case where the wall surface W exists in parallel with the advancing direction V1 on the left side of the advancing direction V1. The ultrasonic wave transmitted from the ultrasonic transmitter s1 is reflected by the wall surface W and reaches the ultrasonic receiver r1 and the ultrasonic receiver r2. From the propagation distance, the distance L11 between the main body 10 and the wall surface W and L12 is obtained respectively. Here, since the distance L11 is smaller than the distance L12, the distance L11 is detected as the separation distance by the detection unit 171f.

  Further, as shown in (b), the following operation is executed based on instruction information from the detection unit 171f to the first transmission unit 171a, the second transmission unit 171b, the first reception unit 171c, and the second reception unit 171d. . First, an ultrasonic wave is transmitted from the ultrasonic transmitter s1 for a predetermined transmission time Ts1 (for example, 2 msec), and a predetermined reception time Tr1 (for example, 4 msec) after the transmission of the ultrasonic wave from the ultrasonic transmitter s1 is started. ) Only by the ultrasonic receiver r1 and the ultrasonic receiver r2. Then, after the reception by the ultrasonic receiver r1 and the ultrasonic receiver r2 is stopped, after a predetermined pause time (for example, 1 msec), the ultrasonic wave is transmitted from the ultrasonic transmitter s2 for a predetermined transmission time Ts2 (for example, 2 msec). The ultrasonic wave is transmitted, and the ultrasonic wave receiver r2 and the ultrasonic wave receiver r3 receive the ultrasonic wave only for a predetermined reception time Tr2 (for example, 4 msec) after the transmission of the ultrasonic wave from the ultrasonic wave transmitter s2 is started.

  Next, after a predetermined pause time (for example, 1 msec) after reception by the ultrasonic receiver r2 and the ultrasonic receiver r3 is stopped, the ultrasonic wave is transmitted from the ultrasonic transmitter s3 for a predetermined transmission time Ts3 (for example, 2 msec). The ultrasonic wave is transmitted and the ultrasonic wave is received by the ultrasonic wave receiver r3 and the ultrasonic wave receiver r4 for a predetermined reception time Tr3 (for example, 4 msec) after the transmission of the ultrasonic wave from the ultrasonic wave transmitter s3 is started. Then, after the reception by the ultrasonic receiver r3 and the ultrasonic receiver r4 is stopped, after a predetermined pause time (for example, 1 msec), the ultrasonic wave is transmitted from the ultrasonic transmitter s1 for a predetermined transmission time Ts1 (for example, 2 msec). A sound wave is transmitted, and the above operation is repeated.

  As described above, the ultrasonic signal transmitted from the ultrasonic transmitter s2 by the ultrasonic receiver r2 and the ultrasonic receiver r3 disposed on both sides of the center line LS, and the reflected signal reflected on the wall surface W. Therefore, the distance between the cleaning robot 1 and the wall surface W is obtained in two directions on the front front using the ultrasonic signal transmitted from the ultrasonic transmitter s2 at the timing of 1. Obstacles are accurately detected.

  Here, when the propagation speed of the ultrasonic wave transmitted from the ultrasonic transmitter 121 in the atmosphere is 340 m / sec, when the reception times Tr1 to Tr3 are 4 msec, the distance from the main body 10 is approximately 680 mm. If the wall surface W exists in the following range, since the ultrasonic wave transmitted from the ultrasonic transmitter 121 is received by the ultrasonic receiver 122, the distance between the main body 10 and the wall surface W is detected in principle. obtain. However, here, for convenience, it is assumed that there is no detectable wall surface W when the distance between the main body 10 and the wall surface W calculated by the distance calculation unit 171e exceeds 200 mm.

  Further, here, when traveling along the wall, the wall surface W is controlled so as to be on the left side in the traveling direction V1 as shown in (a). Further, when traveling along the wall, the direction of the wall surface W used as a reference is set in advance according to the combination of the ultrasonic transmitter 121 and the ultrasonic receiver 122 in which the separation distance is detected. Specifically, as shown in (a), when the distance L11 is detected as the separation distance by the detection unit 171f, the direction of the wall surface W is the direction perpendicular to the line segment indicating the distance L11 ((a). The direction of the straight line LV shown in FIG.

  In addition, in the following description, the wall surface W calculated | required by receiving the ultrasonic signal transmitted from the ultrasonic transmitter si (i = 1-3) with the ultrasonic receiver rj (j = 1-4). A distance from the main body 10 is referred to as a distance Lij.

  Returning to FIG. 3 again, the configuration of the main part of the cleaning robot 1 will be described. The along-wall traveling unit 171g instructs the motors 113a and 113b in the traveling direction so as to travel in the along-wall mode, which is a control mode for traveling along the wall surface (or obstacle). Specifically, a direction (for example, a straight line LV shown in FIG. 4A) set in advance according to the combination of the ultrasonic transmitter 121 and the ultrasonic receiver 122 whose separation distance is detected by the detection unit 171f. Direction).

  The random travel unit 171h is a predetermined value (for example, 20 mm) in which the separation distance detected by the detection unit 171f is set in advance so as to travel in a random mode that is a control mode in which the vehicle travels linearly and rotates repeatedly. ) Go straight until the distance is less than or equal to the following, and when the separation distance detected by the detector 171f is less than or equal to a predetermined value (for example, 20 mm) set in advance, stop straight ahead and change the direction of travel relative to the motors 113a and 113b. It is changed in a predetermined direction. Specifically, for example, the distance is rotated by an angle Δθ (= θ0 + α) with respect to the direction detected by the detection unit 171f (see FIG. 7). However, the angle θ0 is an angle set in advance according to the combination of the ultrasonic transmitter 121 and the ultrasonic receiver 122 in which the separation distance is detected. For example, when the separation distance is detected by the ultrasonic transmitter s2 and the ultrasonic receiver r2, the angle θ0 is 45 degrees, and the separation distance is detected by the ultrasonic transmitter s1 and the ultrasonic receiver r1. In this case, the angle θ0 is 22.5 degrees. In addition, the angle α is an angle that is randomly set in a range of 0 to 90 degrees (for example, a random number is generated and set based on the generated random number).

  The straight travel time measurement unit 171i measures the straight travel time that is the time from the start of straight travel to the stop while traveling in the random mode by the random travel unit 171h, and stores the measured straight travel time in the straight travel time storage unit 172a. To do. That is, the straight traveling time, which is the elapsed time from when the rotation is finished and the straight traveling is started to when the separation distance is equal to or less than a predetermined value (20 mm in this case) is stopped is measured. Is.

  The switching unit 171j switches the random mode to the along-wall mode when the straight traveling time for a predetermined number of times (here, three times) satisfies a predetermined condition (hereinafter referred to as a first condition). Here, the first condition is that the sum of the three straight traveling times is not more than a predetermined threshold value (for example, 3 seconds) set in advance.

  Further, the switching unit 171j randomly selects the wall-side mode when the traveling time in the wall-side mode reaches a predetermined time (for example, 15 seconds) (hereinafter, this condition is referred to as a second condition). Switch to mode. That is, the switching unit 171j switches the random mode to the wall-side mode when the first condition is satisfied, and switches the wall-side mode to the random mode when the second condition is satisfied.

  The prohibition unit 171k prohibits the operation of the switching unit 171j when the running time in the random mode has not reached a predetermined time (for example, 5 minutes) set in advance. That is, the prohibition unit 171k always continues running in the random mode for at least 5 minutes or more when the running in the random mode is started.

  The cleaner control unit 171m performs control related to dust collection, and specifically controls the fan 143, the side brush 16 and the like shown in FIGS.

  The straight running time storage unit 172a stores the straight running time measured by the straight running time measuring unit 171i for three times. In other words, when the straight traveling time after the fourth time is measured by the straight traveling time measuring unit 171i, the straight traveling time stored in the straight traveling time storage unit 172a is stored in the stored order (= measured order). These are sequentially overwritten by the straight time measuring unit 171i.

  FIG. 5 is a diagram illustrating an example of a blind spot when the angle θr that can be received by the ultrasonic receiver 122 is larger than the spread angle θs of the ultrasonic transmitter 121. Here, a case where the receivable angle θr is 150 ° and the spread angle θs is 120 ° is shown. In (a), similarly to the present application, an ultrasonic transmitter sa (corresponding to the ultrasonic transmitter s2 in FIG. 4) is disposed on the center line LS, and ultrasonic waves are received at positions symmetrical with respect to the center line LS. In this case, the devices ra1 and ra2 (corresponding to the ultrasonic receivers r2 and r3 in FIG. 4 respectively) are arranged, and (b) shows that the ultrasonic receiver rb is arranged on the center line LS. This is a case where the ultrasonic transmitters sb1 and sb2 are disposed at positions symmetrical with respect to the center line LS.

  The shaded area in the figure is a detectable range, and the areas BAA and BAB indicated by horizontal lines are blind spots. When the area BAA is narrower than the area BAB and the angle θr that can be received by the ultrasonic receiver 122 is larger than the spread angle θs of the ultrasonic transmitter 121, the arrangement shown in FIG. It can be seen from the arrangement shown in FIG. That is, the sensor arrangement of the present application shown in FIG. 4 may be a good arrangement even in the blind spot when the receivable angle θr of the ultrasonic receiver 122 is larger than the spread angle θs of the ultrasonic transmitter 121. I understand.

  FIG. 6 is a flowchart illustrating an example of the operation of the control unit 17. First, the random travel unit 171h travels in the random mode, and the time for cleaning is started by a timer or the like (step S101). Then, it is determined whether a preset time (for example, 30 minutes) has passed as the cleaning time (step S103). If it is determined that 30 minutes have elapsed (YES in step S103), the process ends. If it is determined that 30 minutes have not elapsed (NO in step S103), whether or not time T1 (5 minutes in this case) has elapsed since the prohibition unit 171k started traveling in the random mode. Is determined (step S105).

  If it is determined that the time T1 or more has not elapsed (that is, the elapsed time is less than 5 minutes) (NO in step S105), the prohibition unit 171k returns the process to step S101. If it is determined that time T1 or more has elapsed (YES in step S105), traveling in a mode (hereinafter referred to as a mixed mode) in which traveling in the random mode and traveling along the wall mode are performed alternately (hereinafter, referred to as mixed mode) is performed ( Step S107).

  Then, it is determined whether or not a preset time (for example, 30 minutes) has passed as the cleaning time (step S109). If it is determined that 30 minutes have elapsed (YES in step S109), the process ends. If it is determined that 30 minutes have not elapsed (NO in step S103), whether or not time T2 (here, 5 minutes) or more has elapsed since the prohibition unit 171k started traveling in the mixed mode. Is determined (step S111). If it is determined that the time T2 or more has not elapsed (that is, the elapsed time is less than 5 minutes) (NO in step S111), the prohibition unit 171k returns the process to step S107. If it is determined that time T2 or more has elapsed (YES in step S111), the process returns to step S101.

  FIG. 7 is a detailed flowchart showing an example of the operation in the mixed travel mode performed in step S107 of the flowchart shown in FIG. The following processing is performed by the switching unit 171j unless otherwise specified. Further, the three straight travel times constituting the condition for switching the random mode to the wall-side mode are referred to as a first straight travel time TS1, a second straight travel time TS2, and a third straight travel time TS3.

  First, the value of the number counter N that counts the number of measurements of the straight traveling time is initialized to 1 (step S201). Then, the straight traveling time TS is initialized to 0, and the time measurement of the straight traveling time TS is started (step S203). Next, traveling in random mode is performed by the random traveling unit 171h (step S205).

  Then, the straight traveling time TS is obtained by the straight traveling time measuring unit 171i (step S207). Next, the first straight travel time TS1 is updated to the value of the second straight travel time TS2, the second straight travel time TS2 is updated to the value of the third straight travel time TS3 by the straight travel time measurement unit 171i, and the third The straight traveling time TS3 is updated to the value of the straight traveling time TS (step S209).

  Then, it is determined whether or not the value of the number counter N is 3 or more (step S211). If it is determined that the value of the number counter N is not 3 or more (NO in step S211), the number counter N is incremented by 1 (step S213), and the process returns to step S203. When it is determined that the value of the number counter N is 3 or more (YES in step S211), a total time TT that is the sum of three straight traveling times (= TS1 + TS2 + TS3) is obtained (step S215), and the total It is determined whether or not the time TT is equal to or greater than a threshold value T0 (here, 3 seconds) (step S217).

  If it is determined that the total time TT is not less than or equal to the threshold value T0 (greater than the threshold value T0) (NO in step S217), the process returns to step S201. When it is determined that the total time TT is equal to or less than the threshold value T0 (YES in step S217), traveling along the wall is performed by the wall traveling section 171g (step S219). Then, it is determined whether or not the elapsed time since the start of traveling along the wall is equal to or longer than a preset time T3 (here, 15 seconds) (step S221). If it is determined that the time is not equal to or greater than time T3 (NO in step S221), the process returns to step S219. If it is determined that the time is equal to or greater than time T3 (YES in step S221), the process is returned (= step S109 in the flowchart shown in FIG. 6 is started).

  FIG. 8 is a detailed flowchart showing an example of the operation in the random travel mode performed in step S101 of the flowchart shown in FIG. 6 and step S205 of the flowchart shown in FIG. The following processing is performed by the random travel unit 171h unless otherwise specified. First, straight travel is started (step S301). Then, the distances L11 to L34 shown in FIG. 4 are measured by the detection unit 171f (step S303). Next, the detection unit 171f determines whether or not the separation distance LM, which is the minimum value among the distances L11 to L34, is equal to or less than a threshold value LSH (here, 20 mm) (step S305).

  If it is determined that it is not less than or equal to threshold value LSH (greater than threshold value LSH) (NO in step S305), the process returns to step S301 and continues straight. If it is determined that it is equal to or less than the threshold value LSH (YES in step S305), the traveling is stopped (step S307). Then, the rotation angle Δθ is obtained as the sum of the angle θ0 set in advance according to the combination of the ultrasonic transmitter 121 and the ultrasonic receiver 122 and the angle α set at random in the range of 0 to 90 degrees. (Step S309). Next, it is rotated by the rotation angle Δθ (= the traveling direction is changed) (step S311), and the process is returned.

  FIG. 9 is a detailed flowchart showing an example of the operation in the wall running mode performed in step S219 of the flowchart shown in FIG. The following processing is performed by the along-wall traveling unit 171g unless otherwise specified. First, the distances L11 to L34 shown in FIG. 4 are measured by the detection unit 171f (step S401). Next, it is rotated in a direction parallel to the nearest wall surface (or obstacle) (step S403). Then, straight travel is started (step S405).

  Next, the distances L11 to L34 are measured by the detection unit 171f (step S407). Then, it is determined whether or not the minimum distance among the distances L22, L23, L33, and L34 is equal to or less than a threshold value LM (here, 20 mm) (step S409). If it is determined that the value is equal to or less than the threshold LM (YES in step S409), the process is returned (the process in step S221 in the flowchart shown in FIG. 7 is started).

If it is determined that it is not less than or equal to the threshold value LM (greater than the threshold value LM) (NO in step S409), parameters α1 to α3 for correcting the traveling direction are obtained by the following equations (1) to (3) (step) S411, 413, 415).
α1 ← (L01−L11) × A11 (1)
α2 ← (L02−L12) × A12 (2)
α3 ← (α1 + α2) / 2 (3)
Here, the distances L01 and L02 are reference distances of the distances L11 and L12 in the travel mode along the wall, respectively. For example, the distances L01 and L02 are values of the distances L11 and L12 in the case where the traveling direction V1 is parallel to the wall surface W and the distance between the main body 10 and the wall surface W is the threshold LM in FIG. Constants A11 and A12 are preset proportionality constants.

Then, the peripheral speeds VR and VL of the left and right wheels are obtained by the following equations (4) and (5) using the current peripheral speed V, respectively, and are instructed to the motors 113a and 113b (step S417). The processing is returned to step S407.
VR ← V−α3 (4)
VL ← V + α3 (5)

  FIG. 10 is a diagram illustrating an example of a control result comparing the above-described mixed traveling mode and conventional traveling control (see Patent Document 1: Japanese Patent Laid-Open No. 2002-136454). FIG. 4 is a plan view of the room in which the cleaning robot 1 is driven, in which (a) shows a running result in conventional running control, and (b) shows a running result in the above-described mixed running mode. In the room AR, two obstacles W1 and W2 are arranged adjacent to each other on the upper left side, and an obstacle W3 is arranged on the lower right side.

  As shown in (a), in the conventional traveling control, seven traveling ranges MCP1 in the wall-side mode are generated in the vicinity of the obstacles W1, W2, and W3. On the other hand, as shown in (b), in the above-described mixed traveling mode, the traveling range MCP2 in the along-wall mode is only three places. In other words, in the conventional traveling control, in the above-described mixed traveling mode, the traveling in the random mode is performed in the majority of the region that is the traveling range in the wall-side mode, and the indoor AR is made more uniform. It is possible to run.

  As described above, an ultrasonic signal transmitted from the ultrasonic transmitter s2 by the ultrasonic receiver r2 and the ultrasonic receiver r3 disposed on both sides of the center line LS, Since the reflected signal reflected at the object) is received, the cleaning robot 1 and the wall surface (or obstacle) in two directions in front of the front using the ultrasonic signal transmitted from the ultrasonic transmitter s2 at one timing. The distance to W is obtained, and the obstacle in front of the front is accurately detected.

  Further, since the ultrasonic receivers r2 and r3 are arranged at positions symmetrical with respect to the center line LS that is a straight line passing through the center O of the main body 10 of the cleaning robot 1 and parallel to the traveling direction V1, The distance between the cleaning robot 1 and the wall surface (or obstacle) W is obtained in two directions on the front front using the ultrasonic signal transmitted from the ultrasonic transmitter s2 at the timing of 1. Obstacles are detected more accurately.

  Furthermore, since only one ultrasonic receiver r2, r3 is disposed on each side of the center line LS, which is a straight line that passes through the center O of the main body 10 of the cleaning robot 1 and is parallel to the traveling direction V1, it is simple. With this configuration, an obstacle in front of the front can be accurately detected.

  In addition, an ultrasonic signal is transmitted in a direction away from the center line LS (= leftward with respect to the traveling direction V1) by the ultrasonic transmitter s1, and the reflected signal reflected on the wall surface (or obstacle) W is super The distance between the cleaning robot 1 and the wall surface (or obstacle) W is obtained using the elapsed time until it is received by the sound wave receivers r1 and r2, and the distance from the center line LS by the ultrasonic transmitter s3. Elapsed time until the ultrasonic signal is transmitted in the direction of separation (= rightward with respect to the traveling direction V1) and the reflected signal reflected by the wall surface (or obstacle) W is received by the ultrasonic receivers r3 and r4. Since the distance between the cleaning robot 1 and the wall surface (or obstacle) W is obtained using time, the distance between the cleaning robot 1 and the wall surface (or obstacle) W in a direction away from the center line LS is obtained. The distance is detected .

  Further, since only one ultrasonic transmitter s1, s3 is disposed at a position symmetrical with respect to the center line LS, the cleaning robot 1 in a direction away from the center line LS can be configured with a simple configuration. A distance from the wall surface (or obstacle) W is detected.

  Furthermore, since the ultrasonic transmitters s1, s2, and s3 are sequentially transmitted in a preset order (in this case, the ultrasonic transmitters s1, s2, and s3), the front in the traveling direction and the traveling direction With respect to the horizontal direction, the distance between the cleaning robot 1 and the wall surface (or obstacle) W is sequentially detected, and appropriate detection is performed.

  In addition, when traveling in the random mode, which is a control mode in which the vehicle travels straight ahead and rotates repeatedly, the straight traveling times TS1 to TS3 for a predetermined number of times (here, three times) satisfy a predetermined condition. Because the random mode is switched to the along-wall mode, which is a control mode that runs along the outer edge of the room, even if the outer edge of the room is a complicated shape, the mode is switched to the along-wall mode at an appropriate frequency. Therefore, it is possible to run the room substantially uniformly.

  In addition, this invention can take the following forms.

  (A) In the present embodiment, the case where the self-propelled robot is the cleaning robot 1 has been described. However, a self-propelled robot that travels substantially uniformly in another predetermined area may be used. For example, a form of a lawn mowing robot including a lawn mower that travels on a lawn such as a garden may be employed.

  (B) Although the case where the distance sensor 12 includes an ultrasonic sensor has been described in the present embodiment, other types of distance sensors (for example, an electromagnetic wave sensor or the like) may be used.

  (C) In the present embodiment, the first receiving unit 171c is connected via two ultrasonic receivers 122 (ultrasonic receivers r2 and r3 disposed on the left and right of the center line LS shown in FIG. 4). Although the case where the reflected signal is received has been described, the reflected signal may be received via three or more (for example, four) ultrasonic receivers 122. In this case, the distance between the cleaning robot 1 and the wall surface (or obstacle) W can be measured more accurately.

  (D) In the present embodiment, the second transmitter 171b includes two ultrasonic transmitters 121 (the ultrasonic transmitters s1 and s3 disposed on the left and right sides with respect to the center line LS shown in FIG. 4). Although the case where the ultrasonic signal is transmitted via the ultrasonic wave transmitter has been described, the ultrasonic signal may be transmitted via three or more (for example, four) ultrasonic transmitters 121. In this case, the distance between the cleaning robot 1 and the wall surface (or obstacle) W can be measured more accurately.

  (E) In the present embodiment, when the ultrasonic transmitters 121 and the ultrasonic receivers 122 are alternately arranged (that is, the ultrasonic reception provided between the two ultrasonic transmitters 121). In the above description, the transmitter 122 receives the ultrasonic signals transmitted from the two ultrasonic transmitters 121 in a time-sharing manner. However, one ultrasonic receiver 122 is transmitted from the single ultrasonic transmitter 121. It is also possible to receive only ultrasonic signals. In this case, it becomes possible to finely adjust the characteristics (for example, frequency characteristics) of the ultrasonic receiver 122 according to the characteristics (for example, the frequency of the ultrasonic waves) of the ultrasonic transmitter 121. It becomes possible to measure the distance to the (or obstacle) W more accurately.

  (F) In the present embodiment, the case where the condition (first condition) for switching the random mode to the along-wall mode is that the sum of the three straight traveling times TS1 to TS3 is less than the threshold value T0 has been described. However, the form which is the other conditions regarding straight traveling time TS1-TS3 may be sufficient. For example, the first condition may be that “the weighted sum of the straight traveling times TS1 to TS3 (for example, 0.5 × TS1 + TS2 + 1.5 × TS3) is less than a predetermined threshold”. In this case, more appropriate travel control can be performed by setting the weight appropriately.

It is a bottom view which shows an example of the cleaning robot which concerns on this invention. It is a perspective view which shows an example of the cleaning robot which concerns on this invention. It is a block diagram which shows an example of the principal part of a cleaning robot. It is explanatory drawing which shows an example of operation | movement of a detection part. It is a figure which shows an example of a blind spot in case the angle (theta) r which can be received of an ultrasonic receiver is larger than the expansion angle (theta) s of an ultrasonic transmitter. It is a flowchart which shows an example of operation | movement of a control part. It is a detailed flowchart which shows an example of the operation | movement in mixed running mode performed by step S107 of the flowchart shown in FIG. FIG. 8 is a detailed flowchart showing an example of an operation in a random travel mode performed in step S101 of the flowchart shown in FIG. 6 and step S205 of the flowchart shown in FIG. It is a detailed flowchart which shows an example of the operation | movement in wall running mode performed by step S219 of the flowchart shown in FIG. It is a figure which shows an example of the control result which compared the above-mentioned mixed driving mode and the conventional driving control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning robot 10 Main-body part 11 Drive part 12 Distance sensor 121 Ultrasonic transmitter (a part of 1st transmission means, a part of 2nd transmission means)
122 Ultrasonic receiver (part of first receiving means, part of second receiving means)
17 control unit 171 CPU
171a 1st transmission part (a part of 1st transmission means)
171b Second transmitter (part of second transmitter)
171c 1st receiving part (a part of 1st receiving means)
171d Second receiver (part of second receiver)
171e Distance calculation unit (distance calculation means)
171f detection part (part of detection means)
171g Traveling along the wall (first traveling means)
171h Random traveling part (second traveling means)
171i Straight running time measuring unit (straight running time measuring means)
171j Switching unit (switching means)
171k Prohibited part (prohibited means)
171m Cleaner control unit 172 RAM
172a Straight running time storage

Claims (7)

A self-propelled robot that travels in a predetermined area, comprising: a drive unit that rotates a drive shaft of at least one wheel at a predetermined rotation speed; and a steering unit that freely sets a traveling direction.
A first transmission means disposed in the vicinity of a center line that is a straight line passing through the center of the self-propelled robot body and parallel to the traveling direction; and transmitting a signal toward the traveling direction of the self-propelled robot;
First receiving means for receiving a signal transmitted by the first transmitting means and reflected at an outer edge of the predetermined area;
Distance calculating means for obtaining a distance between the self-propelled robot and the outer edge of the predetermined area using an elapsed time until the signal transmitted by the first transmitting means is received by the first receiving means; With
The self-propelled robot, wherein the first receiving means is disposed on both sides of the center line.   2. The self-propelled robot according to claim 1, wherein the first receiving unit is disposed at a substantially line-symmetrical position with respect to the center line.   3. The self-propelled robot according to claim 1, wherein only one first receiving unit is provided on each side of the center line. 4. Second transmitting means disposed at a position substantially symmetrical with respect to the center line and transmitting a signal in a direction away from the center line;
A second receiving means for receiving a signal transmitted by the second transmitting means and reflected by an outer edge of the predetermined area;
The distance calculating means uses the elapsed time until the signal transmitted by the second transmitting means is received by the second receiving means, and the distance between the self-propelled robot and the outer edge of the predetermined area. The self-propelled robot according to any one of claims 1 to 3, wherein:   5. The self-propelled robot according to claim 4, wherein each of the second transmitting means is disposed at a position substantially symmetrical with respect to the center line.   The self-propelled robot according to claim 4 or 5, wherein the first transmission unit and the second transmission unit sequentially transmit in a preset order. Detecting means for detecting a distance or a minimum value of a plurality of distances obtained by the distance calculating means as a separation distance;
First traveling means for instructing the steering means in the traveling direction to travel in the first mode, which is a control mode for traveling along the outer edge of the predetermined region;
In order to travel in the second mode, which is a control mode in which the vehicle travels in a straight line and rotates repeatedly, the vehicle travels straight until the separation distance is equal to or less than a predetermined value, and the separation distance is set in advance. Second traveling means for stopping straight traveling and changing the traveling direction to a predetermined direction with respect to the steering means when the value is equal to or less than the predetermined value;
A straight traveling time measuring means for measuring a straight traveling time which is a time from the start of the straight traveling to the stop while traveling in the second mode;
Straight running time storage means for storing straight running time for a predetermined number of times of 2 or more;
Switching means for switching between the first mode and the second mode,
The switching means switches the second mode to the first mode when the straight traveling time for the predetermined number of times satisfies a predetermined condition. A traveling robot.

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