JP2007272677A - Self-propelled device and control method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-propelled device and a control method therefor that can implement an efficient operation by shortening an unnecessary travel distance. <P>SOLUTION: The self-propelled device R comprises driving wheels WL and WR, a forward distance detection part SF for detecting a forward clearance distance LF between the self-propelled device R and a preceding object, a side distance detection part SS for detecting a side clearance distance LS between the self-propelled device R and a side object, and a control part COM for periodically determining whether or not to turn the self-propelled device R according to the detected forward clearance distance LF, and if determining to turn it, calculating an instantaneous center of rotation RC of the self-propelled device R according to the detected forward clearance distance LF and side clearance distance LS and determining the speed of the driving wheels WL and WR according to the calculated instantaneous center of rotation RC. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a self-propelled device and a control method thereof, and more particularly, to a self-propelled device that travels along a wall, such as a cleaning robot and a painting robot, and a control method thereof.

  Conventionally, a self-propelled device such as a cleaning robot is often used along a wall. In a cleaning robot type self-propelled device, in order to clean all corners of a room, a working unit for cleaning is provided at the end of the self-propelled device, and the working unit may have a cornered shape. desirable.

In the self-propelled device having a shape satisfying these conditions, an end portion may come into contact with a surrounding object during turning. In particular, when turning at the corner of the wall, the end of the self-propelled device contacts the wall by turning. For example, when the self-propelled device travels along the right wall of the room and reaches the corner of the room, it needs to turn left, but in the case of such a self-propelled device, if it turns left near the corner of the wall The end of the self-propelled device contacts the wall. It is not preferable for the self-propelled device to rotate forcibly while contacting a surrounding object. In order to solve such problems, for example, Patent Document 1 discloses a self-propelled device as shown below. That is, the self-propelled device travels according to a constant angular turning pattern that combines a plurality of rotations and reverse travels at the corners. Patent Document 2 discloses a self-propelled device as shown below. That is, the self-propelled device includes a slide-type working unit, and selects a turning operation corresponding to the corner of the room. With such a configuration, traveling without an unworked area is realized.
JP 2005-135400 A Japanese Patent Laid-Open No. 5-46239

  However, in the self-propelled devices described in Patent Document 1 and Patent Document 2, it is necessary to reciprocate the distance corresponding to the body of the self-propelled device when turning at the corner of the wall, and there is a problem that there is a lot of wasted travel distance there were.

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a self-propelled device and a control method thereof that can efficiently perform work while shortening a useless traveling distance.

  In order to solve the above problems, a self-propelled device according to an aspect of the present invention includes a pair of drive wheels, a front distance detection unit that detects a front separation distance that is a distance between the self-propelled device and a front object, A side distance detection unit that detects a side separation distance that is a distance between the self-propelled device and a side object, and whether or not to turn the self-propelled device based on the detected front separation distance at a predetermined period. When it is determined to turn, the turning center of the self-propelled device is calculated based on the detected front separation distance and side separation distance, and the speed of each drive wheel is determined based on the calculated turning center. And a control unit.

  Preferably, the self-propelled device further includes a working unit that is disposed in a front portion of the self-propelled device and performs floor work.

  Preferably, the self-propelled device further includes a storage unit that stores a predetermined maximum speed of each driving wheel, and when the control unit determines to turn the self-propelled device, the self-propelled device is based on the calculated turning center. Thus, the speed of one of the pair of drive wheels is determined to be a predetermined maximum speed.

  Preferably, the self-propelled device further includes a storage unit that stores a predetermined maximum speed of each drive wheel, and the control unit further includes a pair of drive wheels when it is determined that the self-propelled device is not turned. At least one of the speeds is determined as a predetermined maximum speed.

  Preferably, the control unit determines to start turning of the self-propelled device when the self-propelled device is not turning and the detected front separation distance is less than the first threshold value. Is determined to end the turning of the self-propelled device when the detected forward separation distance exceeds a second threshold value that is greater than the first threshold value.

  More preferably, the first threshold value is smaller than 1/5 of the longitudinal length of the self-propelled device, and the second threshold value is larger than the longitudinal length of the self-propelled device.

  Preferably, the self-propelled device further includes a front contact detection unit that detects contact with a front object, and the control unit further includes a case where the self-propelled device is not turning and the front contact detection unit is in contact. Is determined to turn the self-propelling device, and if it is determined to turn, the turning center of the self-propelling device is calculated based on the detected lateral separation distance, and based on the calculated turning center Determine the speed of each drive wheel.

  Preferably, the control unit further calculates a turning angle of the self-propelled device after the self-propelled device starts turning, and ends the turning of the self-propelled device when the calculated turning angle is larger than a predetermined value. .

  More preferably, the control unit calculates the turning angle of the self-propelled device based on the time elapsed since the self-propelled device started turning and the determined speed of each drive wheel.

More preferably, the predetermined value is less than 90 degrees.
Preferably, the self-propelled device further includes a contact detection unit that detects contact with the object, and the control unit further includes a case where contact between the self-propelled device and the object is detected during the turning of the self-propelled device. Determines the speed of each drive wheel so that the self-propelled device moves away from the contacted object.

  More preferably, when the contact between the self-propelled device and the object is detected during the turning of the self-propelled device, the control unit drives each drive so that the self-propelled device moves backward by a predetermined distance and then turns by a predetermined angle. Determine the speed of the wheel.

  More preferably, when the contact between the self-propelled device and the object is detected during the turning of the self-propelled device, the control unit retreats the self-propelled device by 1/5 or less of the longitudinal length of the self-propelled device, and then The speed of each drive wheel is determined so as to turn 20 degrees or less.

  Preferably, in the plane parallel to the floor surface on which the self-propelled device travels, the center of the detection range of the front distance detecting unit in the direction perpendicular to the straight traveling direction of the self-propelled device, and the line passing through the front distance detecting unit and the self-propelled device The angle formed with the straight direction is within 30 degrees.

  Preferably, in a plane parallel to the floor surface on which the self-propelled device travels, the center of the detection range of the side distance detection unit in the direction parallel to the straight traveling direction of the self-propelled device and the line passing through the side distance detection unit The angle formed by the straight direction of the traveling device is 60 degrees or more and less than 120 degrees.

  In order to solve the above problems, a control method for a self-propelled device according to an aspect of the present invention is a control method for a self-propelled device including a pair of drive wheels, and the distance between the self-propelled device and a front object. A step of detecting a front separation distance, a step of detecting a side separation distance which is a distance between the self-propelled device and a side object, and a self-propelled device based on the detected front separation distance in a predetermined cycle. If it is decided to turn, the turning center of the self-propelled device is calculated on the basis of the detected front separation distance and side separation distance, and each turning point is calculated based on the calculated turning center. Determining the speed of the drive wheels.

  According to the present invention, it is possible to efficiently perform work by shortening a useless travel distance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<First Embodiment>
FIG. 1 is a plan view showing a configuration of a self-propelled device according to an embodiment of the present invention.

  Referring to the figure, the upper side is the front portion of self-propelled device R. Moreover, as for the shape of the self-propelled apparatus R, the front part is substantially square (square shape), and the rear part is substantially circular. The size of the self-propelled device R is, for example, about 350 mm in the front-rear length and about 350 mm in the left-right width.

  The self-propelled device R includes a drive wheel W, a stepping motor MO, a distance sensor S, a calculation unit (control unit) COM, a battery BT, a front contact sensor (front contact detection unit) BF, and a side contact sensor. (Side contact detection unit) BS and cleaning unit (working unit) CLN are provided. The drive wheel W includes a left drive wheel WL and a right drive wheel WR. The stepping motor MO includes two stepping motors MOL and MOR corresponding to the left and right drive wheels WL and WR. The distance sensor S includes a front distance sensor (front distance detection unit) SF and a side distance sensor (side distance detection unit) SS. The arithmetic unit COM includes a memory MEM, a timer TIM, and a counter CP.

  The cleaning part CLN is disposed in front of the self-propelled device R and cleans the floor surface. With such a configuration, it is possible to easily clean all the corners of a room or the like.

  The distance sensor S is a triangulation type sensor using infrared rays, and measures a separation distance to an object around the self-propelled device R. The front distance sensor SF has a detection range in front of the self-propelled device R, and detects a front separation distance that is a distance between the self-propelled device R and a front object. The lateral distance sensor SS has a detection range on the side of the self-propelled device R, and detects a lateral separation distance that is a distance between the self-propelled device R and a lateral object. The front distance sensor SF and the side distance sensor SS are disposed in the right front portion of the self-propelled device R.

  The front contact sensor BF detects that the front surface of the self-propelled device R has contacted the object. The side contact sensor BS detects that the side surface of the self-propelled device R has contacted the object.

  The stepping motor MO rotates the left driving wheel WL and the right driving wheel WR according to the number of pulses received from the calculation unit COM. Here, the rotation axes of the right drive wheel WR and the left drive wheel WL are coincident.

  The battery BT supplies power for driving the stepping motor MO, the cleaning unit CLN, the distance sensor S, the calculation unit COM, and the like. The battery BT is connected to the stepping motor MO, the cleaning unit CLN, the distance sensor S, the calculation unit COM, and the like by wiring not shown.

  The arithmetic unit COM is, for example, a microcomputer and executes a program stored in the memory MEM or the like. The calculation unit COM is connected to, for example, the left and right stepping motors MO, the distance sensor S, the front contact sensor BF, the side contact sensor BS, and the cleaning unit CLN.

  The counter CP counts the number of pulses (hereinafter also referred to as the number of left and right pulses) input to the left and right stepping motors MO by the calculation unit COM, and stores the count result in the memory MEM.

  The timer TIM measures time and outputs a periodic signal indicating that the predetermined period has elapsed to the arithmetic unit COM every predetermined period, for example, 10 ms.

  The memory MEM includes the distance LW between the left driving wheel WL and the right driving wheel WR, the mounting position PSF of the front distance sensor SF, the mounting position PSS of the side distance sensor SS, and the position of the front end of the self-propelled device R. PC, upper speed limit VMAX of driving wheel W, pulse-distance conversion magnification, left and right pulse number counted by counter CP during corner turning traveling, left and right counted by counter CP during contact avoidance turning described later , The number of left and right pulses counted by the counter CP at the time of contact avoidance retreat described later, the target separation distance LD, calculation formulas F1 to F3 for calculating the instantaneous turning center described later, and drive described later. At least the calculation formulas F4 to F9 for calculating the wheel speed are stored.

FIGS. 2A and 2B are diagrams showing in detail the positional relationship between the self-propelled device R and the wall surface.
With reference to the figure, the attachment position PSF of the front distance sensor SF, the attachment position PSS of the side distance sensor SS, and the front end position PC are stored as coordinates in the robot coordinate system. Here, in the robot coordinate system, an intermediate point between the attachment positions of the left and right drive wheels WL and WR is defined as an origin OR, an extending direction of rotation axes of the left and right drive wheels WL and WR is defined as an x axis, and orthogonal to the x axis. It is a coordinate system in which the straight direction of the self-propelled device R is the y axis. The x axis is perpendicular to the straight direction of the self-propelled device R, and the y axis is parallel to the straight direction of the self-propelled device R.

  The calculation unit COM is based on the front separation distance LF, the side separation distance LS, the attachment position PSF of the front distance sensor SF, the attachment position PSS of the side distance sensor SS detected by the distance sensor S, etc. The instantaneous turning center RC of the self-propelled device R is calculated based on ~ F3. The computing unit COM calculates the target speeds VL and VR of the left driving wheel WL and the right driving wheel WR based on the instantaneous turning center RC calculated by itself, the separation distance LW between the left and right driving wheels WL and WR, and the calculation formulas F4 to F9. calculate.

  The calculation unit COM calculates the moving distance of the self-propelled device R based on the number of left and right pulses counted by the counter CP. Specifically, the arithmetic unit COM calculates the left and right pulse displacement amounts by subtracting the left and right pulse numbers stored at a certain time from the current left and right pulse numbers, and stores them in the left and right pulse displacement amounts in advance. Multiply by the pulse-distance conversion magnification to calculate the left and right driving wheel movement distance, calculate the average value of the left and right driving wheel movement distance, and calculate the movement distance of the self-propelled device R from the average value of the left and right driving wheel movement distance To do. In addition, the calculation unit COM calculates, as the rotation angle of the self-propelled device R, a fan-shaped center angle in which the distance LW between the left and right drive wheels WL and WR is a radius, and the difference between the left and right drive wheel movement distances is the arc length. To do.

  As shown in FIG. 2A, on a plane parallel to the floor surface on which the self-propelled device R travels, the front distance sensor SF is the center line of the detection range in the x-axis direction, that is, the center of the detection range in the x-axis direction. The line passing through the front distance sensor SF is arranged so as to coincide with the straight traveling direction of the self-propelled device R. The lateral distance sensor SS is arranged so that the center line of the detection range in the y-axis direction, that is, the center of the detection range in the y-axis direction and the line passing through the lateral distance sensor SS is orthogonal to the straight traveling direction of the self-propelled device R. ing.

[Operation]
FIG. 3 is a flowchart defining an operation procedure when the self-propelled device according to the embodiment of the present invention travels along the wall.

  The calculation unit COM reads the output of the front distance sensor SF and determines whether or not the front separation distance is less than 20 mm (S31).

  If the calculation unit COM determines that the front separation distance is less than 20 mm (YES in S31), the calculation unit COM performs the corner turning traveling shown in the flowchart of FIG. 4 described later (S33). When the corner turning is completed, the calculation unit COM reads the output of the front distance sensor SF again and determines whether to perform the corner turning (S31).

  When it is determined that the front separation distance is not less than 20 mm (NO in S31), the calculation unit COM reads the output of the front contact sensor BF (S32).

  When the front surface of the self-propelled device R is in contact (YES in S32), the arithmetic unit COM performs the angular turning travel shown in the flowchart of FIG. 4 (S33).

  On the other hand, when the front surface of the self-propelled device R is not in contact (NO in S32), the arithmetic unit COM calculates the left and right drive wheel speeds for traveling along the wall (S34).

  More specifically, the calculation unit COM reads the output of the side distance sensor SS and compares the distance from the side part of the self-propelled device R to the wall with the target separation distance LD stored in the memory MEM in advance. To do.

  When the distance from the side portion of the self-propelled device R to the wall is substantially equal to the target separation distance LD, the calculation unit COM sets the left and right drive wheel speeds VR and VL to the maximum drive wheel speed VMAX. Set.

  Further, when the distance from the side portion of the self-propelled device R to the wall is longer than the target separation distance LD, the calculation unit COM sets the left driving wheel speed VL to the maximum driving wheel speed VMAX and the right driving wheel. The speed VR is set to a value smaller than VMAX.

  In addition, when the distance from the side portion of the self-propelled device R to the wall is shorter than the target separation distance LD, the calculation unit COM sets the right driving wheel speed VR to the maximum driving wheel speed VMAX and sets the left driving wheel. The speed VL is set to a value smaller than VMAX.

  Thus, by setting at least one of the left driving wheel speed VL and the right driving wheel speed VR to the maximum driving wheel speed VMAX, the self-propelled device R can be driven as fast as possible.

  The calculation unit COM outputs the number of pulses corresponding to the calculated left and right drive wheel speeds VL and VR to the left and right stepping motors MO (S35).

  Then, the calculation unit COM reads the output of the timer TIM, waits for the elapse of a cycle time, for example, 10 ms (S36), reads the output of the front distance sensor SF again, and determines whether to perform corner turning (S31). ).

  FIG. 4 is a flowchart that defines an operation procedure when the self-propelled device according to the embodiment of the present invention performs corner turning.

  First, the calculation unit COM determines whether or not cornering traveling should be terminated (S41). Specifically, when the turning angle from the start of cornering turning is greater than 60 degrees (YES in S41), the arithmetic unit COM ends the cornering turning (S43), and reads the output of the front distance sensor SF again. Then, it is determined whether or not cornering traveling is performed (S31).

  When the turning angle is 60 degrees or less (NO in S41) and the forward separation distance detected by the front distance sensor SF is greater than 500 mm (YES in S42), the calculation unit COM ends the corner turning traveling (S43). ) The output of the front distance sensor SF is read again, and it is determined whether or not cornering traveling is to be performed (S31).

  When the turning angle is 60 degrees or less (NO in S41) and the front separation distance is 500 mm or less (NO in S42), the calculation unit COM reads the outputs of the front contact sensor BF and the side contact sensor BS. (S44).

  If the calculation unit COM determines that there is contact between the front part or the side part and the object (YES in S44), the operation avoiding retreat is performed by driving the stepping motors MOL and MOR to retract the self-propelled device R by 15 mm. (S45).

  Specifically, the arithmetic unit COM issues a command to reverse the left and right stepping motors MOL and MOR at a speed that is 1/2 of the maximum speed VMAX. In addition, the calculation unit COM stores the value of the counter CP at the start of the backward movement in the memory MEM. Then, the calculation unit COM checks the value of the counter CP every predetermined cycle based on the cycle signal from the timer TIM, and calculates the travel distance from the start of reverse. The calculation unit COM stops the left and right stepping motors MOL and MOR when the travel distance from the reverse start exceeds 15 mm.

  Then, the calculation unit COM performs a contact avoidance turn that drives the stepping motors MOL and MOR to turn the self-propelled device R five times to the left (S46).

  Specifically, the calculation unit COM issues a reverse command at the maximum speed VMAX to the stepping motor MOL, and issues a forward command at the maximum speed VMAX to the stepping motor MOR. The calculation unit COM stores the value of the counter CP at the start of the left turn in the memory MEM. Then, the calculation unit COM checks the value of the counter CP at every predetermined period based on the periodic signal from the timer TIM, and calculates the turning angle from the start of reverse movement. The calculation unit COM stops the left and right stepping motors MOL and MOR when the turning angle from the reverse start exceeds 5 degrees. Then, the calculation unit COM determines again whether or not the cornering traveling should be terminated (S41).

  With such a configuration, even when contact with an object occurs during cornering traveling, traveling can be continued appropriately.

  If it is determined that there is no contact between the front part and the side part and the object (NO in S44), the calculation unit COM calculates the instantaneous turning center RC (S47). The calculation of the instantaneous turning center RC will be described in detail with reference to the flowchart of FIG.

  Then, the calculation unit COM calculates the left and right drive wheel speeds VL and VR based on the calculated instantaneous turning center RC (S48). The calculation of the left and right drive wheel speeds VL and VR will be described in detail with reference to the flowchart of FIG.

  Then, the calculation unit COM outputs the number of pulses corresponding to the driving wheel speeds VL and VR to the stepping motors MOL and MOR, respectively (S49).

  The arithmetic unit COM receives the periodic signal from the timer TIM, waits for the elapse of a period of time, for example, 10 ms (S4a), and again determines whether or not the cornering traveling should be terminated (S41).

Next, an example of a procedure in which the self-propelled device R performs traveling along the wall and cornering traveling will be described.
The self-propelled device R performs cleaning along the wall that goes around the room along the wall as part of the cleaning work. The self-propelled device R determines whether or not it has approached the corner of the room during cleaning along the wall (S31). If it is determined that it has approached the corner of the room (YES in S31), the cornering traveling is performed. Is started (S33).

  If the corner of the room is larger than 60 degrees, the self-propelled device R ends the corner turning (S43) when it turns 60 degrees or more (YES in S41), and resumes running along the wall (S31). . Here, the bend angle means an angle formed by the extension axis of the front wall surface at the corner of the room and the next wall surface. A turn angle of 0 degrees indicates a state in which the wall is not bent, and a turn angle of 90 degrees is a right angle of the wall. Shows the bent state.

  On the other hand, when the turning angle of the corner of the room is 60 degrees or less, the forward distance sensor SF does not detect the wall when the self-propelled device R turns until it is substantially parallel to the next wall surface. That is, the front separation distance is larger than 500 mm (YES in S42).

  When the front separation distance is greater than 500 mm (YES in S42), the self-propelled device R ends the corner turning traveling (S43) and resumes traveling along the wall (S31).

  Therefore, the self-propelled device according to the embodiment of the present invention can appropriately start and end the corner turning traveling even when the wall turning angle is 60 degrees or less.

  FIG. 5 is a diagram illustrating a simulation result in which the self-propelled device according to the embodiment of the present invention travels on a wall surface having corners of (a) 90 degrees, (b) 60 degrees, and (c) 45 degrees.

  TR is the locus of the origin OR of the robot coordinate system, TC is the locus of the front end position PC of the self-propelled device R, and AREA is the area through which the cleaning unit CLN has passed.

  Referring to the figure, there is almost no uncleaned area along the wall at any corner, and the reciprocation of the front end of self-propelled device R is close to the wall. It can be seen that the movement is only once near the corner of the room, and the reciprocation distance is much smaller than the size of the self-propelled device R.

  Next, the operation when the self-propelled device according to the embodiment of the present invention performs traveling along the wall and cornering traveling on the wall surface where the two corners are continuous will be described.

  FIG. 6 is a diagram showing a state of traveling along a wall and cornering traveling performed by the self-propelled device according to the embodiment of the present invention on a wall surface where two corner portions are continuous.

  As shown in the figure, on the wall surface where the two corners WC1 and WC2 are close to each other, the next corner WC2 approaches the front surface of the self-propelled device R when the self-propelled device R finishes bending the first corner WC1. The front separation distance LF output by the front distance sensor SF is 500 mm or less.

  In such a wall surface, if the self-propelled device R is configured not to perform the determination (S41) as to whether or not the cornering turn should be terminated based on the turning angle from the start of the cornering turning, the front separation distance LF. Is 500 mm or less, the end condition for cornering traveling is not satisfied. For this reason, the self-propelled device R travels at the second corner WC2 while the cornering traveling started by the first corner WC1 is continued. Therefore, the self-propelled device R performs corner turning at a position away from the second corner WC2, and cannot travel close to the corner WC2, so that the uncleaned region in the vicinity of the corner WC2 Will increase.

  However, the self-propelled device according to the embodiment of the present invention has a configuration in which it is determined whether or not the angular turn traveling should be ended based on the turning angle from the start of the angular turn traveling (S41). For this reason, the self-propelled device R determines that the first corner WC1 has been turned when it has rotated more than 60 degrees from the start of the corner turning travel (YES in S41), and resumes traveling along the wall. Approach the second corner WC2. Therefore, in the self-propelled device according to the embodiment of the present invention, the corner turning traveling can be started after approaching the second corner WC2, and the vehicle travels close to each corner. Can do.

  Here, the reason why the turning angle from the start of cornering turning which is the determination criterion for the end of cornering turning is set to 60 degrees will be described.

  In general, many artificial wall surfaces have corners with a turn angle of around 90 degrees. When the self-propelled device R resumes traveling along the wall when the self-propelled device R turns 60 degrees at the corners around 90 degrees, the traveling direction of the self-propelled device is inclined about 30 degrees with respect to the next wall surface. Here, if the inclination is about 40 degrees or less with respect to the wall surface, the self-propelled device R can travel appropriately along the wall shown in the flowchart of FIG. Therefore, in the self-propelled device according to the embodiment of the present invention, the turning angle from the start of the corner turning traveling, which is the criterion for the end of the corner turning traveling, is set to 60 degrees. When the angle is 60 degrees or more and 100 degrees or less, the corner turning can be appropriately started and ended at each corner. For this reason, the self-propelled device according to the embodiment of the present invention can prevent an increase in the uncleaned area in the wall surface shape in which the corners of about 90 degrees are continuous. It should be noted that the turning angle from the start of the corner turning traveling, which is the criterion for the end of the corner turning traveling, is not limited to 60 degrees, but is 50 degrees in which the straight traveling direction of the self-propelled device R is 40 degrees with respect to the wall surface. May be. That is, the turning angle from the start of the corner turning traveling, which is a criterion for the end of the corner turning traveling, can be 50 degrees or more and less than 90 degrees.

  Next, an outline of a method for calculating the instantaneous turning center RC performed by the self-propelled device according to the embodiment of the present invention will be described.

  In the self-propelled device according to the embodiment of the present invention, the instantaneous turning center RC and the drive wheel speed are calculated on the robot coordinate system based on the position of the self-propelled device R described above.

  Referring again to FIG. 2, the calculation unit COM determines the robot coordinate system based on the attachment position PSF of the front distance sensor SF, the attachment position PSS of the side distance sensor SS, the front separation distance LF, and the side separation distance LS. The front object detection position PF and the side object detection position PS are calculated.

  The distance sensor S has a fan-shaped detection range as indicated by a broken line, but the calculation unit COM calculates on the assumption that the object detection position is on the center line of the detection range (the one-dot chain line in FIG. 2A). .

  Referring to FIG. 2B, the calculation unit COM regards a straight line connecting the front object detection position PF and the side object detection position PS as a virtual wall surface V, and the front end position PC of the self-propelled device R. Finds the instantaneous turning center RC for moving in parallel with the virtual wall surface V.

  The instantaneous turning center RC is geometrically defined by a straight line (broken line in FIG. 2 (b)) passing through the front end position PC and perpendicular to the virtual wall surface V, and an x-axis (extension line of the rotation axis of the drive wheel W). Determined as an intersection. The calculation unit COM performs geometric calculation using algebraic expressions and vectors, and calculates the instantaneous turning center RC. Specifically, the arithmetic unit COM executes each step shown in the flowchart of FIG. In FIG. 2, the distance between the self-propelled device R and the wall is drawn to be easy to understand, but actually, the self-propelled device R travels as close to the wall as possible.

  On the turning circle of the instantaneous turning center RC, the front end position PC of the self-propelled device R is the position closest to the virtual wall surface V (in some cases, fitted), and the turning circle at the front end position PC. Is parallel to the virtual wall surface V. Then, by setting the calculation period of the instantaneous turning center RC, that is, the predetermined time in step S4a to be a short time of 10 ms, for example, the distance that the self-propelled device R travels on the turning circle of the calculated instantaneous turning center RC is sufficiently short. Thus, the traveling direction of the front end position PC of the self-propelled device R is substantially parallel to the virtual wall surface V.

  Next, an outline of a driving wheel speed calculation method performed by the self-propelled device according to the embodiment of the present invention will be described.

FIG. 7 is a diagram showing in detail the positional relationship regarding turning of the self-propelled device.
With reference to the figure, the distance LW between the left driving wheel WL and the right driving wheel WR is the distance between the center position in the width direction of the left driving wheel WL and the center position in the width direction of the right driving wheel WR.

  First, the calculation unit COM obtains horizontal distances LL and LR from the instantaneous turning center RC to the ground contact positions of the left and right drive wheels on the x axis. Here, the calculation unit COM calculates on the assumption that the ground contact position of the drive wheel W exists vertically below the center position in the width direction of the rotation axis of the drive wheel W.

  Since the absolute value of the driving wheel speed is proportional to the distance between the driving wheel W and the instantaneous turning center RC, the calculation unit COM determines the speed of the driving wheel W on the side far from the instantaneous turning center RC as the driving wheel W. Is set to the upper speed limit VMAX.

  The calculation unit COM sets the speed of the other driving wheel to a value obtained by multiplying the speed upper limit VMAX of the driving wheel W by the ratio of the horizontal distances LL and LR.

  Further, the calculation unit COM sets the rotation direction of the left driving wheel WL to the vector VL and the rotation direction of the right driving wheel WR to the vector VR, and the front end position PC of the self-propelled device R rotates counterclockwise around the instantaneous turning center RC. Select the direction of rotation.

  Specifically, the arithmetic unit COM executes each step shown in the flowchart of FIG.

  Next, a method for calculating the instantaneous turning center RC performed by the self-propelled device according to the embodiment of the present invention will be described in detail.

  FIG. 8 is a flowchart defining an operation procedure when the self-propelled device according to the embodiment of the present invention calculates the instantaneous turning center RC.

  Referring to FIGS. 8 and 2, calculation unit COM calculates forward object detection position vector PF as a position moved by forward separation distance LF in the y-axis + direction from attachment position PSF of forward distance sensor SF (S81). ). Here, when the cornering traveling is performed because the front surface of the self-propelled device R is in contact (YES in S32), the calculation unit COM calculates the instantaneous turning center RC based only on the side separation distance LS. can do. This is because, when the front surface of the self-propelled device R is in contact, the calculation unit COM can calculate the front object detection position vector PF in a fixed manner from the attachment position PSF of the front distance sensor SF. .

  The computing unit COM calculates the side object detection position vector PS as a position moved from the attachment position PSS of the side distance sensor SS by the side separation distance LS in the x-axis + direction (S82).

  Based on the object detection position vectors PF {PFx, PFy} and PS {PSx, PSy}, the arithmetic unit COM calculates a slope K of a straight line orthogonal to a line segment connecting the object detection position vector PF and the object detection position vector PS below. (S83).

K = (PFx−PSx) / (PSy−PFy) (F1)
A straight line having an inclination of K and passing through the front end position PC {PCx, PCy} of the self-propelled device R is represented by the following expression.

y = K (x-PCx) + PCy (F2)
The calculation unit COM calculates the x coordinate RCx of the instantaneous turning center RC that is the intersection of the straight line represented by the formula (F2) and the x axis by the following formula.

RCx = −PCy / K + PCx (F3)
Formula (F3) is obtained by substituting x = RCx and y = 0 after being transformed into the form for obtaining x in Formula (F2).

As described above, the calculation unit COM calculates the instantaneous turning center RC {RCx, 0}.
Next, a method of calculating the instantaneous turning center performed by the self-propelled device according to the embodiment of the present invention will be described in detail.

  FIG. 9 is a flowchart defining an operation procedure when the self-propelled device according to the embodiment of the present invention calculates the drive wheel speed.

  Referring to FIG. 9 and FIG. 7, the calculation unit COM calculates a horizontal distance LL from the instantaneous turning center RC to the ground contact position of the left driving wheel WL (S91). Here, since the distance between the left driving wheel WL and the right driving wheel WR is LW and the origin OR is the midpoint of the left driving wheel WL and the right driving wheel WR, the grounding position of the left driving wheel WL is {− LW / 2, 0}. Accordingly, the horizontal distance LL from the instantaneous turning center RC to the ground contact position of the left drive wheel WL is expressed by the following equation.

LL = RCx + LW / 2 (F4)
In the formula (F4), the sign LL represents the positional relationship between the instantaneous turning center RC and the ground contact position of the left drive wheel WL. That is, when the sign of LL is positive, the instantaneous turning center RC is on the right side from the grounding position of the left driving wheel WL, and when the sign of LL is negative, the instantaneous turning center RC is on the left side of the grounding position of the left driving wheel WL. become.

  The calculation unit COM calculates the horizontal distance LR from the instantaneous turning center RC to the ground contact position of the right drive wheel WR by the following formula (S92).

LR = RCx−LW / 2 (F5)
The arithmetic unit COM compares the absolute values of LL and LR, and if the absolute value of LL is larger (YES in S93), it calculates the speed VL of the left drive wheel WL by the following formula (S94).
VL = −VMAX × LL / | LL | (F6)
From Expression (F6), VL is a value obtained by multiplying −VMAX by the sign of LL.

  Next, the calculation unit COM calculates the speed VR of the right drive wheel WR by the following formula (F7) (S95).

VR = −VMAX × | LR | / | LL | × LR / | LR | (F7)
On the other hand, the arithmetic unit COM compares the absolute values of LL and LR. If the absolute value of LR is equal to or greater than the absolute value of LL (NO in S93), the speed VR of the right drive wheel WR is calculated by the following equation. Calculate (S94).

VR = −VMAX × LR / | LR | (F8)
From equation (F8), VR is a value obtained by multiplying -VMAX by the sign of LR.

Next, the calculation unit COM calculates the speed VL of the left drive wheel WL by the following formula.
VL = −VMAX × | LL | / | LR | × LL / | LL | (F9)
As described above, the calculation unit COM calculates the left and right drive wheel speeds VL and VR. In the signs of the drive wheel speeds VL and VR, positive represents the forward direction and negative represents the reverse direction. Since the self-propelled device according to the embodiment of the present invention is configured to travel along the right wall, the turning direction at the corner is a left turn.

  As described above, also in the corner turning traveling, the self-propelled device R can be turned as fast as possible by setting at least one of the left driving wheel speed VL and the right driving wheel speed VR to the maximum driving wheel speed VMAX. it can.

[Modification 1]
Although the self-propelled device according to the embodiment of the present invention is configured to travel along the right wall, the present invention is not limited to this and may be configured to travel along the left wall.

  In this case, the front distance sensor SF and the side distance sensor SS are attached to the left front portion of the self-propelled device R.

  Furthermore, the process of step S34 during traveling along the wall is as follows. That is, the calculation unit COM reads the output of the side distance sensor SS and compares the distance from the side part of the self-propelled device R to the wall with the target separation distance LD stored in advance in the memory MEM.

  When the distance from the side portion of the self-propelled device R to the wall is substantially equal to the target separation distance LD, the calculation unit COM sets both the left and right driving wheel speeds VL and VR to the maximum driving wheel speed VMAX.

  In addition, when the distance from the side portion of the self-propelled device R to the wall is longer than the target separation distance LD, the calculation unit COM sets the right driving wheel speed VR to the maximum driving wheel speed VMAX and sets the left driving wheel. The speed VL is set to a value smaller than VMAX.

  In addition, when the distance from the side portion of the self-propelled device R to the wall is shorter than the target separation distance LD, the calculation unit COM sets the left driving wheel speed VL to the maximum driving wheel speed VMAX and the right driving wheel. The speed VR is set to a value smaller than VMAX.

  Furthermore, the process of step S82 in the flowchart of FIG. 8 is as follows. That is, the calculation unit COM calculates the side object detection position vector PS as a position moved from the attachment position PSS of the side distance sensor SS by the side separation distance LS in the x-axis direction. Further, in the calculation formulas (F6) to (F9) for the drive wheel speed, -VMAX on the right side is replaced with VMAX (the negative sign is removed).

  Furthermore, the process of step S46 in the flowchart of FIG. 4 is as follows. That is, the calculation unit COM performs contact avoidance turning by driving the stepping motors MOL and MOR and turning the self-propelled device to the right by 5 degrees.

  Since the configuration and operation other than those described above are the same as those of the self-propelled device according to the embodiment of the present invention, detailed description thereof will not be repeated here.

[Modification 2]
In the self-propelled device according to the embodiment of the present invention, in the plane parallel to the floor surface on which the self-propelled device R travels, the front distance sensor SF has the center line of the detection range in the x-axis direction straight ahead of the self-propelled device R. The lateral distance sensor SS is arranged so as to coincide with the direction, and the center line of the detection range in the y-axis direction is arranged so as to be orthogonal to the straight traveling direction of the self-propelled device R. It is not limited. The center line of the detection range in the x-axis direction of the front distance sensor SF does not coincide with the rectilinear direction of the self-propelled device R, and the center line of the detection range in the y-axis direction of the side distance sensor SS is the rectilinear direction of the self-propelled device R. It is also possible to adopt a configuration that is not orthogonal to.

  More specifically, the memory MEM in the calculation unit COM stores the attachment angle θF of the front distance sensor SF and the attachment angle θS of the side distance sensor SS.

  Here, the attachment angle θF of the front distance sensor SF is an angle formed by the center line of the detection range of the front distance sensor SF in the x-axis direction and the straight traveling direction of the self-propelled device R. The mounting angle θS of the side distance sensor SS is an angle formed by the center line of the detection range of the side distance sensor SS in the y-axis direction and the straight traveling direction of the self-propelled device R.

  In this case, the process of step S81 in the flowchart shown in FIG. 8 is as follows. That is, the calculation unit COM calculates the front object detection position PF by the following equation based on the attachment position PSF of the front distance sensor SF, the front separation distance LF, and the attachment angle θF of the front distance sensor SF.

PF = PSF + {LF × cos (θF), LF × sin (θF)} (F10)
Furthermore, the process of step S82 of the flowchart shown in FIG. 8 is as follows. That is, the calculation unit COM calculates the side object detection position PS by the following formula based on the attachment position PSS of the side distance sensor SS, the side separation distance LS, and the attachment angle θS of the side distance sensor SS.

PS = PSS + {LS × cos (θS), LS × sin (θS)} (F11)
Since the configuration and operation other than those described above are the same as those of the self-propelled device according to the embodiment of the present invention, detailed description thereof will not be repeated here.

  With the configuration described above, the center line of the detection range in the x-axis direction of the front distance sensor SF does not coincide with the straight direction of the self-propelled device R, and the center line of the detection range in the y-axis direction of the side distance sensor SS is The present invention can also be applied to configurations that are not orthogonal to the straight direction of the self-propelled device R.

  Note that the angle formed by the center line of the detection range of the forward distance sensor SF in the x-axis direction and the straight traveling direction of the self-propelled device R is within 30 degrees in order to detect an object in front of the self-propelled device R. preferable. Further, the mounting angle θS of the side distance sensor SS is an angle formed by the center line of the detection range of the side distance sensor SS in the y-axis direction and the straight traveling direction of the self-propelled device R. In order to detect an object, a configuration of 60 degrees or more and less than 120 degrees is preferable.

  By the way, in the self-propelled device described in Patent Document 1 and Patent Document 2, it is necessary to reciprocate the distance of the self-propelled device main body when turning at the corner of the wall, and there is a problem that there is a lot of useless traveling distance. there were. However, in the self-propelled device according to the embodiment of the present invention, the calculation unit COM is configured to detect the angle of the self-propelled device R based on the front separation distance LF and the side separation distance LS detected by the distance sensor S at a predetermined period. It is determined whether or not to turn, that is, whether or not to turn, and when it is determined to turn, the instantaneous turning center RC of the self-propelled device R is calculated based on the front separation distance LF and the side separation distance LS. The speed of each drive wheel is determined based on the calculated instantaneous turning center RC. With such a configuration, an optimum turning center can be calculated at a predetermined cycle, and the front part of the self-propelled device R where the cleaning part CLN is arranged can move in parallel with the wall. For example, as shown in FIG. The reciprocation distance when turning at the corner of the wall can be reduced, and the wasteful travel distance can be shortened and work can be performed efficiently. Even if the driving wheel slips and the accurate movement amount and turning angle of the self-propelling device cannot be measured, the front separation distance LF and the side separation distance LS are immediately set in the next cycle when the driving wheel slips. Based on this, the instantaneous turning center and the left and right drive wheel speeds can be updated, so that the vehicle can travel stably without greatly leaving the wall.

  In addition, the number of times of contact with the wall surface can be reduced as compared with a self-propelled device that travels along a simple wall that turns a little if it goes straight and touches the wall, thereby improving the merchantability.

  Moreover, since the self-propelled devices described in Patent Document 1 and Patent Document 2 are configured to turn with a constant radius, there is a problem in that there is a lot of useless travel distance such as an increase in the number of reciprocations. However, in the self-propelled device according to the embodiment of the present invention, the instantaneous turning center RC of the self-propelled device R is calculated based on the front separation distance LF and the side separation distance LS, and based on the calculated instantaneous turning center RC. The turning radius of each driving wheel is calculated, and the speed of each driving wheel is determined based on the calculated turning radius. With such a configuration, an optimum turning radius can be calculated at a predetermined cycle, and the front part of the self-propelled device R where the cleaning part CLN is arranged can move in parallel with the wall, thereby shortening the useless travel distance. Work can be done efficiently.

  In addition, the self-propelled device described in Patent Document 1 requires a rotation angle sensor and a plurality of front sensors, and further requires a slide mechanism for a working unit. In the self-propelled device according to the embodiment of the invention, the rotation angle sensor is unnecessary, and only one front distance sensor is required, and the manufacturing cost can be reduced.

  Moreover, since the self-propelled device described in Patent Document 2 performs turning based on the current position after measuring the current position based on the travel distance, it is appropriate in a situation where accurate position measurement cannot be performed due to slipping or the like. There is a problem that it cannot turn, it cannot handle corners of different angles with a constant traveling pattern, and it cannot handle narrow spaces because it needs to move away from the wall when turning at corners. is there. However, in the self-propelled device according to the embodiment of the present invention, the calculation unit COM calculates the instantaneous turning center RC of the self-propelled device R based on the front separation distance LF and the side separation distance LS in a predetermined cycle. Since the speed of each drive wheel is determined based on the instantaneous turning center RC, it is possible to turn along the wall properly even when slippage or the like occurs and the accurate travel distance cannot be measured. It can correspond to corners of various angles. Moreover, since the operation | movement which leaves | separates from a wall is unnecessary when turning in a corner | angular part, it can work appropriately also in a narrow place.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a top view which shows the structure of the self-propelled apparatus which concerns on embodiment of this invention. (A) And (b) is a figure which shows the positional relationship of the self-propelled apparatus R and a wall surface in detail. It is the flowchart which defined the operation | movement procedure at the time of the self-propelled apparatus which concerns on embodiment of this invention traveling along a wall. It is the flowchart which defined the operation | movement procedure at the time of the self-propelled apparatus which concerns on embodiment of this invention performing corner turning driving | running | working. (a) 90 degree | times, (b) 60 degree | times, (c) It is a figure which shows the simulation result which the self-propelled apparatus which concerns on embodiment of this invention drive | works the wall surface which has a 45 degree | times corner. It is a figure which shows the mode of the traveling along a wall and the corner turning traveling which the self-propelled apparatus which concerns on embodiment of this invention performs in the wall surface which two corner | angular parts continue. It is a figure which shows the positional relationship regarding turning of a self-propelled device in detail. It is the flowchart which defined the operation | movement procedure at the time of the self-propelling apparatus which concerns on embodiment of this invention calculating instantaneous turning center RC. It is the flowchart which defined the operation | movement procedure at the time of the self-propelled apparatus which concerns on embodiment of this invention calculating drive wheel speed.

Explanation of symbols

  R self-propelled device, W drive wheel, MO, MOL, MOR stepping motor, S distance sensor, COM calculation unit (control unit), BT battery, BF front contact sensor (front contact detection unit), BS side contact sensor (side Side contact detection unit), CLN cleaning unit (working unit), WR right drive wheel, WL left drive wheel, SF front distance sensor (front distance detection unit), SS side distance sensor (side distance detection unit), MEM memory , TIM timer, CP counter, PSF, PSS installation position, PC front end position, RC instantaneous turning center, OR origin, LF forward separation distance, LS lateral separation distance, LW separation distance, LD target separation distance, LL, LR Horizontal distance, VL, VR Target speed, VMAX Maximum driving wheel speed.

Claims (16)

A self-propelled device,
A pair of drive wheels;
A front distance detection unit that detects a front separation distance that is a distance between the self-propelled device and a front object;
A lateral distance detection unit that detects a lateral separation distance that is a distance between the self-propelled device and a lateral object;
In a predetermined cycle, it is determined whether or not the self-propelled device is to be turned based on the detected front separation distance, and when it is determined to be turned, based on the detected front separation distance and side separation distance. A self-propelled device including a control unit that calculates a turning center of the self-propelled device and determines a speed of each drive wheel based on the calculated turning center.   The said self-propelled apparatus is a self-propelled apparatus of Claim 1 provided with the operation | work part which is arrange | positioned in the front part of the said self-propelled apparatus and performs a floor work. The self-propelled device further includes a storage unit that stores a predetermined maximum speed of each driving wheel,
The control unit, when determining to turn the self-propelled device, determines the speed of one of the pair of driving wheels to the predetermined maximum speed based on the calculated turning center. The self-propelled device described. The self-propelled device further includes a storage unit that stores a predetermined maximum speed of each driving wheel,
2. The self-propelled vehicle according to claim 1, wherein the control unit further determines the speed of at least one of the pair of driving wheels to be the predetermined maximum speed when it is determined not to turn the self-propelled device. apparatus.   The control unit determines to start turning of the self-propelled device when the self-propelled device is not turning and the detected forward separation distance is less than a first threshold. 2. The turning of the self-propelled device is determined to end when the traveling device is turning and the detected forward separation distance exceeds a second threshold value that is greater than the first threshold value. Self-propelled device.   The self-propelled device according to claim 5, wherein the first threshold value is smaller than 1/5 of the front-rear length of the self-propelled device, and the second threshold value is larger than the front-rear length of the self-propelled device. The self-propelled device further includes a front contact detection unit that detects contact with a front object,
The control unit further determines that the self-propelled device is to be turned when the self-propelled device is not turning, and the front contact detection unit detects contact, and determines that the self-propelled device is to be turned. The self-propelled device according to claim 1, wherein the center of rotation of the self-propelled device is calculated based on the detected lateral separation distance, and the speed of each driving wheel is determined based on the calculated center of rotation.   The control unit further calculates a turning angle of the self-propelled device after the self-propelled device starts turning, and turns the self-propelled device when the calculated turning angle is larger than a predetermined value. The self-propelled device according to claim 1, which is terminated.   The self-propelled device according to claim 8, wherein the control unit calculates a turning angle of the self-propelled device based on a time elapsed since the self-propelled device started turning and the determined speed of each driving wheel.   The self-propelled device according to claim 8, wherein the predetermined value is less than 90 degrees. The self-propelled device further includes a contact detection unit that detects contact with an object,
The control unit further controls the speed of each driving wheel so that the self-propelled device is separated from the contacted object when contact between the self-propelled device and the object is detected during the turning of the self-propelled device. The self-propelled device according to claim 1, which determines   When the contact between the self-propelled device and the object is detected during the turning of the self-propelled device, the control unit moves the self-propelled device backward by a predetermined distance, and then turns each predetermined angle. The self-propelled device according to claim 11, wherein the speed of the driving wheel is determined.   When the contact between the self-propelled device and the object is detected during the turning of the self-propelled device, the control unit retreats the self-propelled device by 1/5 or less of the longitudinal length of the self-propelled device, 13. The self-propelled device according to claim 12, wherein the speed of each drive wheel is determined so as to turn 20 degrees or less.   In a plane parallel to the floor surface on which the self-propelled device travels, the center of the detection range of the front distance detection unit in a direction perpendicular to the straight traveling direction of the self-propelled device, and a line passing through the front distance detection unit The self-propelled device according to claim 1, wherein an angle formed by the straight direction of the traveling device is within 30 degrees.   In a plane parallel to the floor surface on which the self-propelled device travels, the center of the detection range of the lateral distance detection unit in a direction parallel to the straight traveling direction of the self-propelled device, and a line passing through the side distance detection unit The self-propelled device according to claim 1, wherein an angle formed by the straight traveling direction of the self-propelled device is 60 degrees or more and less than 120 degrees. A control method for a self-propelled device having a pair of drive wheels,
Detecting a front separation distance that is a distance between the self-propelled device and a front object;
Detecting a lateral separation distance that is a distance between the self-propelled device and a lateral object;
In a predetermined cycle, it is determined whether or not the self-propelled device is to be turned based on the detected front separation distance, and when it is determined to be turned, based on the detected front separation distance and side separation distance. Calculating the turning center of the self-propelled device and determining the speed of each drive wheel based on the calculated turning center.

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