JP4278634B2 - Self-propelled robot - Google Patents

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. For example, Patent Document 1 discloses a self-propelled cleaning that performs movement control when moving along an obstacle and obstacle avoidance control that changes the moving direction of the main body when an obstacle is detected during movement of the main body. A machine has been proposed.

More specifically, when an obstacle is detected and the obstacle is avoided by the obstacle avoidance control, and the obstacle is detected again within a predetermined time, the main body is moved for a predetermined time by the movement control.
JP 2002-136454 A

  However, in the self-propelled cleaner disclosed in Patent Document 1, when there are many obstacles in the room, or when the wall surface of the room has a complicated shape, the frequency of the movement control is low. It has increased in number, and it has been difficult to run the room substantially uniformly.

  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 traveling substantially uniformly within a predetermined area.

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 detects a separation distance that is a distance that a main body of the self-propelled robot is separated from an outer edge of the predetermined region, and travels along the outer edge of the predetermined region In this control mode, the first traveling means for instructing the steering means to travel in the first mode, which is the control mode, and the traveling in the predetermined region are repeatedly performed in a straight line and a rotation. In order to run in the second mode, 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, the straight travel is stopped and the steering means Progress toward A second traveling means for changing the direction in the predetermined direction, the time at which the straight running time to the stop from the straight running starting traveling in the second mode, a straight time measuring means for measuring, at least two predetermined consecutive 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 separation distance which is the distance which the main body of a self-propelled robot is spaced apart from the outer edge of a predetermined area | region is detected by the detection means. 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.

Furthermore, the self-propelled robot according to claim 1 is characterized in that the predetermined condition is that a sum of straight running times for the predetermined number of consecutive times is equal to or less than a predetermined threshold value set in advance.

According to the above configuration, since the control mode is switched from the second mode to the first mode when the sum of the straight traveling times for a predetermined number of consecutive times is equal to or less than a predetermined threshold value, simple processing is performed. Thus, it is possible to travel substantially uniformly within a predetermined area.

The self-propelled robot according to claim 2 is characterized in that the predetermined number of times is three.

  According to the above configuration, since the predetermined number of times is 3, the control mode is switched from the second mode to the first mode at an appropriate frequency.

The self-propelled robot according to claim 3 , wherein the switching unit switches the first mode to the second mode when the traveling time in the first mode reaches a predetermined time set in advance. It is characterized by.

  According to the above configuration, the control mode is switched from the first mode to the second mode when the traveling time in the first mode reaches a predetermined time set in advance by the switching means. Travel time is restricted, and it is possible to travel more uniformly within a predetermined region.

5. The self-propelled robot according to claim 4 , further comprising a prohibiting unit that prohibits the operation of the switching unit when the traveling time in the second mode has not reached a predetermined time set in advance. It is said.

  According to the above configuration, the operation of the switching unit is prohibited by the prohibiting unit when the traveling time in the second mode has not reached the predetermined time set in advance.

  Therefore, when the travel time in the second mode has not reached the predetermined time set in advance, it is prohibited to switch the second mode to the first mode, so the travel time in the second mode is ensured. This makes it possible to travel more uniformly in a predetermined area.

The self-propelled robot according to claim 5 , wherein the detection means detects a distance between a plurality of predetermined positions set in advance in a main body of the self-propelled robot and an outer edge of the predetermined region. The minimum value of the distance is detected as the separation distance.

  According to the above configuration, the detecting means detects the distances between a plurality of predetermined positions preset in the main body of the self-propelled robot and the outer edge of the predetermined region, and the detected minimum distances are separated from each other. Detected as distance.

  Accordingly, since the minimum value of the distances between a plurality of predetermined positions set in advance in the main body of the self-propelled robot and the outer edge of the predetermined area is detected as the separation distance, the separation distance can be detected more appropriately.

The self-propelled robot according to claim 6 is provided with a dust collecting means for collecting dust on a traveling surface in the predetermined area.

  According to the above configuration, since the traveling surface in the predetermined area is collected by the dust collecting means, a self-propelled cleaning robot that travels substantially uniformly in the predetermined area and collects the traveling surface is realized. Is done.

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

Further , according to the first aspect of the present invention, the control mode is switched from the second mode to the first mode when the sum of the straight traveling times for a predetermined number of consecutive times is equal to or less than a predetermined threshold value set in advance. Therefore, it is possible to travel substantially uniformly within a predetermined area with a simple process.

According to the second aspect of the present invention, since the predetermined number of times is 3, the control mode can be switched from the second mode to the first mode at an appropriate frequency.

According to the third aspect of the present invention, when the traveling time in the first mode reaches a predetermined time set in advance, the control mode is switched from the first mode to the second mode. Travel time is restricted, and the vehicle can travel more uniformly in a predetermined area.

According to the fourth aspect of the present invention, when the traveling time in the second mode does not reach the predetermined time set in advance, the control mode is prohibited from being switched from the second mode to the first mode. Therefore, the traveling time in the second mode is ensured, and it is possible to travel more uniformly in the predetermined area.

According to the fifth aspect of the present invention, since the minimum value of the distances between the plurality of predetermined positions preset in the main body of the self-propelled robot and the outer edge of the predetermined region is detected as the separation distance, Furthermore, it can detect appropriately.

According to the invention described in claim 6 , it is possible to realize a self-propelled cleaning robot that travels substantially uniformly in a predetermined area and collects dust on the traveling surface.

  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 a floor surface (corresponding to a traveling surface) in 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 that measures the distance to the wall, a bumper 13 that detects contact with a wall surface (or an obstacle), and a dust collecting portion 14 (corresponding to a part of the dust collecting means) that collects the floor surface. The auxiliary wheel 15 that supports the main body 10 substantially parallel to the floor surface, and the side brush 16 that moves dust near the wall surface (or obstacle) toward the main body 10 (corresponding to a part of the dust collecting means) And a control unit 17 (not shown: see FIG. 3) for controlling the operation of the entire cleaning robot 1.

  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 is configured by three ultrasonic transmitters 121 and four ultrasonic receivers 122 being 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 a wall, the left side of the traveling direction V1 is separated from the wall surface (or obstacle) 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 includes a detection unit 171a (corresponding to detection means) that detects a separation distance, which is a distance that the main body unit 10 is separated from the wall surface (or obstacle), and a wall surface (or obstacle). In order to travel in the along-wall mode (corresponding to the first mode), which is a control mode for traveling along the wall, the wall-side traveling unit 171b (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. Random traveling unit 171c (which travels straight and stops the straight traveling when the separation distance is equal to or less than a predetermined value set in advance and changes the traveling direction to a predetermined direction with respect to motors 113a and 113b) And a corresponding) and a second carriage means.

  In addition, the CPU 171 functionally includes a straight traveling time measurement unit 171d (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 mode along the wall. A switching unit 171e (corresponding to switching means) for switching between the random mode and the random mode, and a prohibiting unit 171f for prohibiting the operation of the switching unit 171e when the traveling time in the random mode has not reached a predetermined time set in advance. (Corresponding to prohibition means) and a cleaner control unit 171g for performing 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).

  The detection unit 171a detects a minimum value of a plurality of distances detected by the three ultrasonic transmitters 121 and the four ultrasonic receivers 122 arranged in the bumper 13 as a 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 171a.

  (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 to (a), with respect to the advancing direction V1, centering on the ultrasonic transmitter s2 (tip position of the advancing direction V1), it is equidistant and 3 ultrasonic transmitters 121 and 4 super The sound wave receivers 122 are alternately arranged. 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 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 171a.

  Also, as shown in (b), first, ultrasonic waves are transmitted from the ultrasonic transmitter s1 for a predetermined transmission time (for example, 2 msec), and transmission of ultrasonic waves from the ultrasonic transmitter s1 is started. It is received by the ultrasonic receiver r1 and the ultrasonic receiver r2 for a predetermined reception time (for example, 4 msec). Then, after the reception at the ultrasonic receiver r1 and the ultrasonic receiver r2 is stopped, the ultrasonic wave is transmitted from the ultrasonic transmitter s2 for a predetermined transmission time (for example, 2 msec) after a predetermined pause time (for example, 1 msec). Is transmitted by the ultrasonic receiver r2 and the ultrasonic receiver r3 for a predetermined reception time (for example, 4 msec) after the transmission of ultrasonic waves from the ultrasonic transmitter s2 is started.

  Next, ultrasonic waves are transmitted from the ultrasonic transmitter s3 for a predetermined transmission time (for example, 2 msec) after a predetermined pause (for example, 1 msec) after reception by the ultrasonic receiver r2 and the ultrasonic receiver r3 is stopped. Is transmitted by the ultrasonic receiver r3 and the ultrasonic receiver r4 for a predetermined reception time (for example, 4 msec) after the ultrasonic transmission from the ultrasonic transmitter s3 is started. Then, after reception by the ultrasonic receiver r3 and the ultrasonic receiver r4 is stopped, ultrasonic waves are transmitted from the ultrasonic transmitter s1 for a predetermined transmission time (for example, 2 msec) after a predetermined pause time (for example, 1 msec). Is transmitted, and the above operation is repeated.

  Here, in the case where the reception time is 4 msec, if the wall surface W exists in a range where the distance from the main body 10 is approximately 200 mm or less, the ultrasonic wave emitted from the ultrasonic transmitter 121 is transmitted to the ultrasonic receiver 122. And the distance between the main body 10 and the wall surface W is detected. That is, here, when the wall surface W does not exist in the range where the distance from the main body portion 10 is approximately 200 mm or less, the distance between the main body portion 10 and the wall surface W is not detected.

  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 by the detection unit 171a as the separation distance, the direction of the wall surface W is a direction perpendicular to the line segment indicating the distance L11 ((a). The direction of the straight line LV shown in FIG.

  Returning to FIG. 3 again, the configuration of the main part of the cleaning robot 1 will be described. The along-wall traveling unit 171b 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 171a. Direction).

  The random travel unit 171c has a predetermined distance (for example, 20 mm) in which the separation distance detected by the detection unit 171a is set so as to travel in a random mode, which is a control mode in which the vehicle travels linearly and rotates repeatedly. ) Go straight ahead until the distance is less than or equal to the predetermined distance (for example, 20 mm) set in advance by the detection unit 171a, and stop straight 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 171a (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 traveling time measuring unit 171d measures a straight traveling time that is a time from the start of straight traveling to a stop while traveling in the random mode by the random traveling unit 171c, and stores the measured straight traveling time in the straight traveling 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 171e 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.

  In addition, the switching unit 171e randomly selects the along-wall mode when the traveling time in the along-wall 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 171e switches the random mode to the wall along mode when the first condition is satisfied, and switches the random mode to the wall along mode when the second condition is satisfied.

  The prohibition unit 171f prohibits the operation of the switching unit 171e when the traveling time in the random mode has not reached a predetermined time (for example, 5 minutes) set in advance. That is, the prohibition unit 171f always keeps 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 171g performs control related to dust collection, and specifically controls the fan 143 and the side brush 16 shown in FIGS.

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

  FIG. 5 is a flowchart illustrating an example of the operation of the control unit 17. First, the random travel unit 171c travels in the random mode, and the cleaning time 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 (here, 5 minutes) has elapsed since the prohibition unit 171f 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 171f 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 171f 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 171f returns the process to step S107. If it is determined that time T1 or more has elapsed (YES in step S111), the process returns to step S101.

  FIG. 6 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 171e 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 the random mode is performed by the random traveling unit 171c (step S205).

  Then, the straight traveling time TS is obtained by the straight traveling time measuring unit 171d (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, and the third straight travel time TS1 is updated by the third straight travel time TS3. 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), the travel along the wall is performed by the travel unit 171b along the wall (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. 5 is started).

  FIG. 7 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. 5 and step S205 of the flowchart shown in FIG. The following processing is performed by the random travel unit 171c unless otherwise specified. First, straight travel is started (step S301). And the distances L11-L34 shown in FIG. 4 are measured by the detection part 171a (step S303). Next, the detection unit 171a 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. 8 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 171b unless otherwise specified. First, the distances L11 to L34 shown in FIG. 4 are measured by the detection unit 171a (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 171a (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. 6 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), respectively, instructed to the motors 113a and 113b (step S417), and the process returns to step S407.
VR ← V−α3 (4)
VL ← V + α3 (5)

  FIG. 9 is a diagram illustrating an example of a control result comparing the above-described mixed traveling mode with the 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, the straight traveling time TS1 to TS3 for a predetermined number of times (three times in this case) while traveling in a random mode that is a control mode in which the vehicle travels linearly and rotates repeatedly satisfies a predetermined condition. When satisfying, since 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 has a complicated shape, the mode along the wall is moderately frequent It becomes possible to run in the room substantially uniformly.

  In addition, when the sum of the straight traveling times TS1 to TS3 (total time TT) for a predetermined number of times (here, 3 times) is equal to or less than a threshold value T0 (here, 3 seconds), the random mode is switched to the wall-side mode. Therefore, it is possible to run the room substantially uniformly with a simple process.

  Furthermore, since the predetermined number of times is 3, the random mode is switched to the along-wall mode at an appropriate frequency.

  In addition, when the running time in the wall-side mode reaches a preset time (15 seconds in this case), the wall-side mode is switched to the random mode, so the running time in the wall-side mode is restricted. As a result, it becomes possible to travel even more uniformly in the room.

  In addition, when the running time in the random mode has not reached the predetermined time set in advance (here, 5 minutes), it is prohibited to switch the random mode to the wall-side mode. The traveling time is ensured, and it is possible to travel more uniformly in the room.

  Further, since the distance sensor 12 detects the minimum values of the distances L11 to L34 (see FIG. 4) between a plurality of (six in this case) predetermined positions and the indoor outer edge as the separation distance LM, the separation distance LM is further increased. Appropriate detection is possible.

  In addition, since the floor surface of the room is collected by the dust collection unit 14, the side brush 16, and the like, a self-propelled cleaning robot that travels substantially uniformly in the room and collects the floor surface is realized.

  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 case where the distance sensor 12 measures the six distances L11 to L34 (see FIG. 4) with the outer edge of the room has been described. However, the distance sensor 12 may measure at least two distances. . The smaller the number of sensors, the cheaper the cleaning robot 1 becomes.

  (D) In the present embodiment, the case where the drive unit 11 rotates the drive wheels 111a and 111b by the motors 113a and 113b (that is, the case where the drive unit 11 is driven and steered by the drive unit 11) has been described. 11 may be configured to drive one driving wheel with one motor and change the traveling direction separately from the driving unit 11.

  (E) In this 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 flowchart which shows an example of operation | movement of a control part. FIG. 6 is a detailed flowchart showing an example of an operation in a mixed traveling mode performed in step S107 of the flowchart shown in FIG. 5. 6 is a detailed flowchart illustrating an example of an operation in a random travel mode performed in step S101 of the flowchart illustrated in FIG. 5 and step S205 of the flowchart illustrated in FIG. 6. 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 13 Bumper 14 Dust collection part 15 Auxiliary wheel 16 Side brush 17 Control part 171 CPU
171a Detection part (part of detection means)
171b Traveling section along the wall (first traveling means)
171c Random traveling part (second traveling means)
171d Straight travel time measurement unit (straight travel time measurement means)
171e Switching part (switching means)
171f Prohibited part (prohibited means)
171g Cleaner control unit 172 RAM
172a Straight running time storage

Claims (6)

A self-propelled robot that travels in a predetermined area, comprising: 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.
Detecting means for detecting a separation distance, which is a distance that the body of the self-propelled robot is separated from the outer edge of the predetermined region;
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;
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 straight traveling to the stop during traveling in the second mode;
Straight running time storage means for storing straight running times for two or more consecutive predetermined times;
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 ,
The self-propelled robot is characterized in that the predetermined condition is that a sum of the straight traveling times for the predetermined number of times is equal to or less than a predetermined threshold value set in advance. The self-propelled robot according to claim 1 , wherein the predetermined number of times is three. Said switching means, when the running time in the first mode reaches a preset predetermined time, any one of claims 1-2, characterized in that switching the first mode to the second mode The self-propelled robot described in 1. If the running time in the second mode has not reached the preset predetermined time, according to any one of claims 1 to 3, characterized in that it comprises inhibiting means for inhibiting the operation of said switching means Self-propelled robot. The detection means detects a distance between a plurality of predetermined positions set in advance in the main body of the self-propelled robot and an outer edge of the predetermined region, and detects a minimum value of the detected plurality of distances as the separation distance. The self-propelled robot according to any one of claims 1 to 4 . The self-propelled robot according to any one of claims 1 to 5 , further comprising dust collecting means for collecting a traveling surface in the predetermined area.

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