Image processing device, autonomous mobile robot

Abstract

To provide an image processing device capable of suppressing a deterioration in the accuracy of reading a part to be detected by grasping an inclination in a roll direction of the part to be detected, and an autonomous mobile robot.SOLUTION: An image processing device for detecting a part C to be detected in which a plurality of cells C11, C12... are arranged on a two-dimensional plane has a calculation part for calculating an inclination of the part C to be detected on the basis of a relative displacement amount (L1-L2) in a Y-axis direction orthogonal to an X-axis direction of two cells C11, C13 arranged in the X-axis direction and a relative displacement amount (L3-L4) in the X-axis direction of two cells C11, C31 arranged in the Y-axis direction in the part C to be detected.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image processing device and an autonomous mobile robot. [Background technology]

[0002] Conventionally, there are known an image processing device, a control system for a mobile robot, and a control method for a mobile robot, as described in the following Patent Document 1. This image processing device includes a detection unit including a detection object, which is a square or rectangular cell on a two-dimensional plane, and is configured by arranging a first cell capable of reflecting irradiated light and a second cell unable to reflect the irradiated light in a matrix of a×a or a×b (where a, b=3, 4, 5, 6, ...), an irradiation unit that irradiates light, an imaging unit that captures the light reflected from the first cell by a camera after the light irradiated from the irradiation unit is irradiated to the first cell and the second cell that constitute the detection object, and a calculation unit that acquires information set on the detection object based on the imaging data captured by the imaging unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-102047 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, a detection target portion in which a plurality of cells are arranged on a two-dimensional plane is installed, for example, on the movement path of an autonomous mobile robot and used as a sign post to guide the autonomous mobile robot. However, when installing such a detection target portion, the detection target portion may be tilted in the roll direction. In that case, it may be difficult for an image processing device to read the detection target portion.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide an image processing device and an autonomous mobile robot that can grasp the roll-directional inclination of the detected part and suppress a decrease in the reading accuracy of the detected part. [Means for solving the problem]

[0006] In order to solve the above problems, the image processing device of the present invention is an image processing device that detects a detectable portion in which a plurality of cells are arranged on a two-dimensional plane, and has a calculation unit that calculates the inclination of the detectable portion based on the relative displacement amount in a secondary direction perpendicular to the primary direction of two cells arranged in a primary direction in the detectable portion, and the relative displacement amount in the primary direction of two cells arranged in the secondary direction.

[0007] In addition, the autonomous mobile robot of the present invention is an autonomous mobile robot that reads a sign having a detectable portion in which a number of cells are arranged on a two-dimensional plane using an imaging unit mounted thereon, and moves guided by the sign, and is equipped with the image processing device described above. Effect of the Invention

[0008] According to the present invention, the inclination of the detection part in the roll direction can be grasped, and a decrease in the reading accuracy of the detection part can be suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing an autonomous mobile robot in a first embodiment of the present invention moving as viewed from above. FIG. [Diagram 2] 1 is a block diagram showing a configuration of an autonomous mobile robot in a first embodiment of the present invention. [Diagram 3] 2 is a front view showing an example of a detected portion of a sign post that is read by a sign post detection unit in the first embodiment of the present invention. FIG. [Figure 4] FIG. 4 is a flowchart showing image processing of the autonomous mobile robot in the first embodiment of the present invention. [Diagram 5]FIG. 4 is a flowchart showing image processing of the autonomous mobile robot in the first embodiment of the present invention. [Figure 6] FIG. 4 is an image diagram showing a captured image including a detection target portion inclined in the roll direction in the first embodiment of the present invention. [Figure 7] FIG. 11 is a flowchart showing image processing of an autonomous mobile robot in a second embodiment of the present invention. [Figure 8] FIG. 11 is a flowchart showing image processing of an autonomous mobile robot in a second embodiment of the present invention. [Figure 9] FIG. 11 is an image diagram showing a captured image including a detection part tilted in the roll direction in the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (First embodiment) FIG. 1 is a schematic diagram showing the movement of an autonomous mobile robot 1 in a first embodiment of the present invention, viewed from above. 1, the autonomous mobile robot 1 moves while sequentially reading a number of sign posts SP arranged along a travel route 10 with an imaging unit 26 mounted on the robot body 20. In other words, the autonomous mobile robot 1 moves along the travel route 10 while being guided by the number of sign posts SP.

[0012] Here, the term "signpost" refers to a structure having a sign (marker) and placed at a predetermined location on the travel route 10 or near the travel route 10. The sign includes identification information (target ID) of the structure. As shown in FIG. 3 described later, the sign in this embodiment is a detectable portion C in which first cells (cells C11, C13...) capable of reflecting light and second cells (cells C12, C21...) unable to reflect light are arranged on a two-dimensional plane. The sign may be a one-dimensional code (barcode) or other two-dimensional code.

[0013] FIG. 2 is a block diagram showing the configuration of the autonomous mobile robot 1 in the first embodiment of the present invention. As shown in FIG. 2, the autonomous mobile robot 1 includes a signpost detection unit 21 (image processing device), a drive unit 22, a control unit 23, and a communication unit 24.

[0014] The sign post detection unit 21 has an illumination unit 25, two imaging units 26, and a calculation unit 27. The drive unit 22 has a motor control unit 28, two motors 29, and left and right drive wheels 20L, 20R. Note that the configurations of the sign post detection unit 21 and the drive unit 22 are merely examples, and other configurations may be used.

[0015] The irradiation unit 25 is attached to the center of the front of the autonomous mobile robot 1 in the traveling direction, and irradiates, for example, infrared LED light forward. Infrared LED light is suitable for dark places such as in factories and places with strong visible light. The irradiation unit 25 may be configured to irradiate detection light other than infrared LED light.

[0016] The two imaging units 26 are disposed on the left and right of the sign post detection unit 21. The two imaging units 26 are, for example, cameras combined with infrared filters, and capture the light (infrared LED light) reflected by the sign post SP.

[0017] The calculation unit 27 performs a binarization process based on the captured images transmitted from the two imaging units 26 to form binary image data consisting of black and white, and then uses the binarized image data to perform calculations using triangulation (triangulation using the difference between the captured images of the two imaging units 26) to calculate the distance (distance Z) and direction (angle θ) at which the signpost SP is located relative to the autonomous mobile robot 1.

[0018] In addition, when the captured image includes multiple sign posts SP, the calculation unit 27 detects the identification information (target ID) of the sign posts SP to select the target sign post SP, and calculates the distance Z and angle θ to the target sign post SP.

[0019] Drive wheel 20L is provided on the left side in the direction of travel of autonomous mobile robot 1. Drive wheel 20R is provided on the right side in the direction of travel of autonomous mobile robot 1. Note that autonomous mobile robot 1 may have wheels other than drive wheels 20L, 20R to stabilize the posture of autonomous mobile robot 1. The motor 29 rotates the left and right drive wheels 20L, 20R in response to the control of the motor control unit .

[0020] Motor control unit 28 supplies power to left and right motors 29 based on the angular velocity command value input from control unit 23. Autonomous mobile robot 1 moves forward or backward as left and right motors 29 rotate at an angular velocity according to the power supplied from motor control unit 28. In addition, the traveling direction of autonomous mobile robot 1 is changed by generating a difference between the angular velocities of left and right motors 29.

[0021] The control unit 23 controls the drive unit 22 based on the information read from the sign post SP by the sign post detection unit 21.

[0022] 1, the autonomous mobile robot 1 moves while maintaining a fixed distance from the left side of the travel route 10. In order to maintain a fixed distance from the left side of the travel route 10, the autonomous mobile robot 1 determines the distance Xref to the sign post SP, acquires the distance Z and angle θ to the detected sign post SP, and calculates a traveling direction in which the distance Z and angle θ satisfy a predetermined condition.

[0023] Angle θ is the angle between the traveling direction of the autonomous mobile robot 1 and the direction of the detected sign post SP. The autonomous mobile robot 1 moves forward so that the distance between the sign post SP and the target route is Xref. When the distance Z to the guided sign post SP (e.g., sign post SP1) becomes closer than a predetermined threshold, the autonomous mobile robot 1 switches the target to the next sign post SP (e.g., sign post SP2) and moves forward. Note that sign post SP2 represents a state in which it is tilted in the roll direction. The roll direction refers to the direction of revolution around the roll axis, when the axis extending perpendicular to the surface of the sign post SP (specifically, the detected part C described later) is taken as the roll axis.

[0024] FIG. 3 is a front view showing an example of the detection target portion C of the sign post SP that is read by the sign post detection unit 21 in the first embodiment of the present invention. As shown in Figure 3, the sign post SP has a detection area C in which first cells (cells C11, C13, ...) capable of reflecting infrared LED light and second cells (cells C12, C21, ...) not capable of reflecting infrared LED light are arranged on a two-dimensional plane.

[0025] The detection target portion C of this embodiment is formed of a matrix pattern of 3 rows x 3 columns. Specifically, the detection target portion C includes a cell C11 (first cell) in the first row and first column, a cell C12 (second cell) in the first row and second column, a cell C13 (first cell) in the first row and third column, a cell C21 (second cell) in the second row and first column, a cell C22 (first cell) in the second row and second column, a cell C23 (second cell) in the second row and third column, a cell C31 (first cell) in the third row and first column, a cell C32 (second cell) in the third row and second column, and a cell C33 (first cell) in the third row and third column.

[0026] The first cells (cells C11, C13, C22, C31, and C33) are formed of a material with high reflectance to infrared LED light, such as aluminum foil, a thin film of titanium oxide, etc. The second cells (cells C12, C21, C23, and C32) are formed of a material with low reflectance to infrared LED light, such as an infrared cut film, a polarizing film, an infrared absorbing material, or black felt.

[0027] The calculation unit 27 detects the sign post SP by performing a first scan SC1 and a second scan SC2 on the detection target C included in the captured image captured by the imaging unit 26. In the first scan SC1, for example, cell C11 (first cell), cell C12 (second cell), and cell C13 (first cell) arranged in the first row in the order of "white, black, white" are detected. In the second scan SC2, for example, cell C11 (first cell), cell C21 (second cell), and cell C31 (first cell) arranged in the first column in the order of "white, black, white" are detected.

[0028] When expressed in binary code with white being "1" and black being "0 (zero)", "white, black, white" can be expressed as "1, 0, 1", and the calculation unit 27 detects the sign post SP when it successfully reads "1, 0, 1" by the first scan SC1 and "1, 0, 1" by the second scan SC2.

[0029] The calculation unit 27 reads the identification information (target ID) of the sign post SP from the remaining cells (cell C22 in the second row, second column, cell C23 in the second row, third column, cell C32 in the third row, second column, and cell C33 in the third row, third column) of the detection target C. In the example shown in Fig. 3, the calculation unit 27 can read the identification information of the sign post SP with 4-bit information.

[0030] As described above, the detection target portion C has a detection target area C10 for the sign post detection unit 21 to detect the detection target portion C, and an identification area 20C for the sign post detection unit 21 to identify the detection target portion C. The detection target area C10 includes a start bar C10a (first area) consisting of cells C11, C12, and C13 in the first row of the detection target portion C, and a stop bar C10b (second area) consisting of cells C11, C21, and C31 in the first column of the detection target portion C.

[0031] The start bar C10a and the stop bar C10b partially overlap in the first row, first column of the detection portion C. That is, the cell C11 in the first row, first column forms part of the start bar C10a and the stop bar C10b. The identification area 20C includes a cell C22 in the second row, second column, a cell C23 in the second row, third column, a cell C32 in the third row, second column, and a cell C33 in the third row, third column.

[0032] 2, the communication unit 24 communicates with a higher-level system (not shown). The higher-level system (not shown) provides the autonomous mobile robot 1 with identification information (target ID) of a sign post SP to be detected, based on the current position of the autonomous mobile robot 1 on the travel route 10, for example.

[0033] The flow of image processing by the autonomous mobile robot 1 (signpost detection unit 21) described above will be specifically explained below with reference to Figures 4 to 6. In the following explanation, unless otherwise specified, calculations related to image processing by the autonomous mobile robot 1 are performed by the calculation unit 27. Calculations related to driving control of the autonomous mobile robot 1 are performed by the control unit 23.

[0034] Fig. 4 and Fig. 5 are flow diagrams showing image processing of the autonomous mobile robot 1 in the first embodiment of the present invention. Note that the numbers 1-2 in circles shown in Fig. 4 and Fig. 5 indicate the connection between the two flows shown in Fig. 4 and Fig. 5. Fig. 6 is an image diagram showing a captured image including a detection target part C tilted in the roll direction in the first embodiment of the present invention. The calculation unit 27 starts a process of detecting the detection target portion C (signature) from the captured image shown in Fig. 6 (step S1). Note that the following process is executed for each frame (each image) of the captured image captured by the imaging unit 26.

[0035] First, as shown in FIG. 6, scanning is performed line by line in the X-axis direction from the coordinates (X0, Y0) of the captured image (first scanning SC1 described above), nThe widths w1, w2, and w3 of the white (first cell), black (second cell), and white (first cell) of the th row are checked (step S2). In the captured image, the upper left corner of the captured image is set to the origin coordinates (X0, Y0), the horizontal direction is set to the X-axis direction (primary direction), and the vertical direction of the captured image is set to the Y-axis direction (secondary direction). Also, the right side of the horizontal direction of the captured image is the + side in the X-axis direction, and the lower side of the vertical direction of the captured image is the + side in the Y-axis direction.

[0036] Next, it is determined whether or not there is a sequence of white, black, and white with the widths w1, w2, and w3 being equally spaced (step S3). Note that the presence of a sequence of white, black, and white with the widths w1, w2, and w3 being equally spaced means that, when the initially detected white width w1 is taken as a reference, the subsequently detected black width w2 and white width w3 are within a range of, for example, ±10% of the width w1.

[0037] If the answer is "YES" in step S3, n X in line n ~X n+3 The start bar C10a is considered to be up to the white / black boundary position X n ~X n+3 is stored (step S4). If the answer is "NO" in step S3, the variable n is incremented by 1, and the process returns to step S2 to determine the next Y n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0038] After step S4, the center position X of the width w1 in the X-axis direction is S (Step S5). Then, the center position X S The column containing n Then, scanning is performed from this position (the second scanning SC2 described above) (step S6). Next, in the second scanning SC2 in step S6, it is determined whether or not there is a sequence of white, black, and white (step S7).

[0039] If the answer is "YES" in step S7, press X SThe white, black, and white in the 1st row are regarded as stop bars C10b. From the height h2 of the black (cell C21) in the Y-axis direction, which became obvious in the second scan SC2, and the height h3 of the white (cell C31) in the Y-axis direction, the center position Y of the black (cell C21) in the Y-axis direction is calculated. n+1 , the center position Y of the white cell (cell C31) in the Y-axis direction n+2 is calculated (step S8). If the answer is "NO" in step S7, the variable n is incremented by 1, and the process returns to step S2 to determine the next Y n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0040] After step S8, the lengths L1, L2, L3, and L4 shown in FIG. 6 are scanned to find the lengths (step S21 in FIG. 5). The length L1 is calculated based on the coordinates (X S ,Y n ) to the Y-axis -side (upper side of the paper), and the length L2 is the distance in the Y-axis direction from the coordinate (X n+2 +w3 / 2,Y n ) to the Y-axis -side (upper side of the paper), and the length L3 is the distance in the Y-axis direction from the coordinate (X S ,Y n ) to the negative side of the X axis (left side of the paper), and the length L4 is the distance in the X axis direction from the coordinate (X S ,Y n+2 ) to the negative side of the X axis (left side of the page) and then to the black and white boundary.

[0041] After step S21, the slope a of the change in the X-axis direction from the lengths L1 and L2 is Y Calculate the slope a of the change in the Y-axis direction from the lengths L3 and L4. X That is, the calculation unit 27 calculates the inclination a of the detection target C based on the relative displacement (L1-L2) in the Y-axis direction perpendicular to the X-axis direction of the two cells C11 and C13 aligned in the X-axis direction in the detection target C and the relative displacement (L3-L4) in the X-axis direction of the two cells C11 and C31 aligned in the Y-axis direction. X ,a YCalculate.

[0042] After step S22, the slope a X ,a Y Using the above, P1' to P6' (black and white boundary coordinates) after rotation are calculated for each coordinate P1 to P6 of the discrimination area C20 of the detection target C by the following formulas (1) to (4) (step S23). N are the coordinates when the detection target C has no inclination (when the inclination is zero). N ' is the coordinate of the detection target part C in the tilted state (after roll rotation). P N =(X N ,Y N ) …(1) P N ´=(X N ´,Y N ´) …(2) X N ´=X N +a X (Y N -Y n ) …(3) Y N ´=Y N +a Y (X N -X S ) …(4)

[0043] After step S23, four locations (cells C22, C23, C32, and C33) of the discrimination region C20 are scanned as follows (1) to (4), and it is determined whether each cell is black or white (step S24). 1. The area from start point P1' to end point P2' 2. The section from start point P2' to end point P3' 3. The section from start point P4' to end point P5' 4. The section from start point P5´ to end point P6´

[0044] After step S24, the scanning results of 1. to 4. are read as a binary code in which the white cells C22, C23, and C32 are set to 1 and the black cell C33 is set to 0, and these are converted and calculated as decimal ID information (step S25).

[0045] Next, it is determined whether or not the ID information is the same as the set ID (target ID) (step S26). If "YES" in step S26, the center of gravity coordinate G of the detected detection target portion C is output from its outline coordinates (step S27), thereby completing the series of processes for detecting and reading the detection target portion C. If the answer is "NO" in step S26, the variable n is incremented by 1, and the process returns to step S2 to determine the next Y n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0046] In this way, according to the above-described first embodiment, the sign post detection unit 21 detects the detection target C in which a plurality of cells C11, C12, ... are arranged on a two-dimensional plane, and calculates the inclination a of the detection target C based on the relative displacement amount (L1-L2) in the Y-axis direction perpendicular to the X-axis direction of two cells C11, C13 aligned in the X-axis direction in the detection target C, and the relative displacement amount (L3-L4) in the X-axis direction of two cells C11, C31 aligned in the Y-axis direction. X ,a Y According to this configuration, since it is possible to grasp how much the detection target portion C is tilted in the roll direction, it is possible to improve the accuracy of reading the detection target portion C.

[0047] Furthermore, according to the first embodiment, the detectable portion C has a detectable area C10 for the sign post detection unit 21 to detect the detectable portion C, and the calculation unit 27 detects the detectable area C10 by scanning in the X-axis direction and the Y-axis direction, and calculates the inclination of the detectable portion C from the cells C11, C13, and C31 included in the detectable area C10. According to this configuration, the inclination of the detectable portion C can be calculated using the cells C11, C13, and C31 that become obvious by the detection of the detectable area C10 of the detectable portion C, and therefore the efficiency of the calculation process can be improved.

[0048] Furthermore, according to the first embodiment, the detection area C10 includes a start bar C10a detected by scanning in the X-axis direction, and a stop bar C10b detected by scanning in the Y-axis direction and partially overlapping the start bar C10a. The calculation unit 27 calculates the inclination a of the detection area C based on the relative displacement (L1-L2) in the Y-axis direction of the cell C11 arranged in the area where the start bar C10a and the stop bar C10b overlap, and another cell C13 included in the start bar C10a, and the relative displacement (L3-L4) in the X-axis direction of the cell C11 arranged in the area where the start bar C10a and the stop bar C10b overlap, and another cell C31 included in the stop bar C10b. X ,a Y According to this configuration, the inclination of the detected portion C can be calculated from three cells including the cell C11 arranged in the area where the start bar C10a and the stop bar C10b overlap, so that the calculation process can be made more efficient than calculating the inclination of the detected portion C from four cells.

[0049] According to the first embodiment, the detection target C has an identification area C20 for the sign post detection unit 21 to identify the detection target C, and the calculation unit 27 determines the direction of scanning the identification area C20 based on the inclination a of the detection target C. X ,a Y According to this configuration, as shown in Fig. 6, the scanning in the identification area C20 is performed in an oblique direction according to the inclination of the detection target C, thereby improving the reading accuracy of the detection target C that is set at an angle.

[0050] Furthermore, according to the first embodiment, an autonomous mobile robot 1 reads a sign post SP having a detectable part C in which a number of cells C11, C12... are arranged on a two-dimensional plane using the mounted imaging unit 26, and moves by being guided by the sign post SP. By being equipped with the above-mentioned sign post detection unit 21, the robot can grasp the inclination of the detectable part C in the roll direction, suppressing a decrease in the accuracy of reading the detectable part C, enabling stable movement.

[0051] Second embodiment Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent configurations as those in the above-described embodiment are given the same reference numerals, and the description thereof will be simplified or omitted.

[0052] Fig. 7 and Fig. 8 are flow diagrams showing image processing of the autonomous mobile robot 1 in the second embodiment of the present invention. Note that the numbers 3-4 in circles shown in Fig. 7 and Fig. 8 indicate the connection between the two flows shown in Fig. 7 and Fig. 8. Fig. 9 is an image diagram showing a captured image including a detection target part C tilted in the roll direction in the second embodiment of the present invention. The calculation unit 27 starts a process of detecting the detection target C (sign) from the captured image shown in Fig. 9 (step S31). In the detection target C of the second embodiment, the cells C21, C22, and C23 in the second row configure the identification area C20, and the cells C31, C32, and C33 in the third row configure the stop bar C10b of the detection target area C10.

[0053] First, as shown in FIG. 9, scanning is performed line by line in the X-axis direction from the coordinates (X0, Y0) of the captured image (first scanning SC1 described above), n The widths w1, w2, and w3 of the white (first cell), black (second cell), and white (first cell) in the row are checked (step S32). Next, it is determined whether there is a row of white, black, and white with the widths w1, w2, and w3 being equally spaced (step S33).

[0054] If "YES" in step S33, Y n X in line n ~X n+3 The start bar C10a is considered to be up to the white / black boundary position X n ~X n+3 is stored (step S34). If the answer is "NO" in step S33, the variable n is incremented by 1, and the process returns to step S32 to determine the next Y n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0055] Next in step S34, the average w of the three widths w1, w2, and w3 is calculated.ave (Step S35). Next, Y n Whereas, w ave Add twice the size of Y to detect the stop bar C10b. n+2 (Step S36). Next, Y n+2 X in line n From X n+3 Then, in the second scanning SC2 in step S37, it is determined whether or not there is a sequence of white, black, and white (step S38).

[0056] If "YES" in step S38, Y n+2 The white, black, and white in the 1st row are regarded as stop bars C10b, and the boundary position X in the X-axis direction between the white (cell C31) and black (cell C32) that became obvious in the second scan SC2 is S is stored (step S39). If the answer is "NO" in step S38, the variable n is incremented by 1, and the process returns to step S32 to determine the next Y n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0057] After step S39, the lengths L1, L2, and D1 shown in FIG. 9 are calculated (step S41 in FIG. 8). The length L1 is calculated based on the coordinates (X n +w1 / 2,Y n ) to the Y-axis -side (upper side of the paper), and the length L2 is the distance in the Y-axis direction from the coordinate (X n+2 +w3 / 2,Y n ) to the Y-axis -side (upper side of the paper) and the distance in the Y-axis direction to the black-white boundary. The length D1 is n+1 -X S It is.

[0058] After step S41, the slope a of the change in the X-axis direction from the lengths L1 and L2 is Y Calculate the slope a of the change in the Y-axis direction from the length D1. XThat is, the calculation unit 27 calculates the inclination a of the detection target C based on the relative displacement (L1-L2) in the Y-axis direction perpendicular to the X-axis direction of the two cells C11 and C13 aligned in the X-axis direction in the detection target C, and the relative displacement (D1) in the X-axis direction of the two cells C11 and C31 aligned in the Y-axis direction. X ,a Y Calculate.

[0059] After step S42, the slope a X ,a Y Using the above, P1' to P4' (black and white boundary coordinates) after rotation are calculated for each coordinate P1 to P4 of the discrimination area C20 of the detection target C by the following formulas (1) to (4) (step S43). N are the coordinates when the detection target C has no inclination (when the inclination is zero). N ' is the coordinate of the detection target part C in the tilted state (after roll rotation). P N =(X N ,Y N ) …(1) P N ´=(X N ´,Y N ´) …(2) X N ´=X N +a X (Y N -Y n ) …(3) Y N ´=Y N +a Y (X N -X S ) …(4)

[0060] After step S43, three locations (cells C21, C22, and C23) of the discrimination region C20 are scanned as follows (1) to (3), and it is determined whether each cell is black or white (step S44). 1. The area from start point P1' to end point P2' 2. The section from start point P2' to end point P3' 3. The section from start point P3' to end point P4'

[0061] After step S44, the scanning results of 1. to 3. are read as a binary code in which the white cells C22 and C23 are set to 1 and the black cell C21 is set to 0, and these are converted and calculated as decimal ID information (step S45).

[0062] Next, it is determined whether or not the ID information is the same as the set ID (target ID) (step S46). If "YES" in step S46, the center of gravity coordinate G of the detected detection target portion C is output from its outline coordinates (step S47), thereby completing the series of processes for detecting and reading the detection target portion C. If the answer is "NO" in step S46, the variable n is incremented by 1, and the process returns to step S4. n+1 Check the widths w1, w2, and w3 of white (first cell), black (second cell), and white (first cell) in the row.

[0063] As described above, according to the second embodiment, the detection area C10 includes the start bar C10a detected by scanning in the X-axis direction, and the stop bar C10b detected by scanning in the X-axis direction and arranged at a different position in the Y-axis direction from the start bar C10a, and the calculation unit 27 calculates the inclination a of the detection area C based on the relative displacement (L1-L2) in the Y-axis direction between the cell C11 arranged at one end of the start bar C10a and another cell C13 included in the start bar C10a, and the relative displacement (D1) in the X-axis direction between the cell C11 arranged at one end of the start bar C10a and the cell C31 arranged at one end of the stop bar C10b. X ,a Y According to this configuration, the inclination of the detection target portion C can be calculated from three cells including the cell C11 arranged at one end of the start bar C10a, so that the calculation process can be made more efficient than when the inclination of the detection target portion C is calculated from four cells.

[0064] Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The shapes and combinations of the components shown in the above embodiment are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0065] For example, in the above embodiment, the start bar C10a is set in the X-axis direction, but the start bar C10a may be set in the Y-axis direction. That is, the detection target portion C may be configured such that the calculation unit 27 can detect the detection target region C10 by scanning in at least one of the X-axis direction and the Y-axis direction.

[0066] Also, for example, in the above embodiment, the autonomous mobile robot 1 is a vehicle, but the autonomous mobile robot 1 may be an air vehicle commonly known as a drone. Also, for example, in the above embodiment, a configuration in which a plurality of sign posts SP are arranged along the travel route 10 has been described, but a configuration in which only one sign post SP is arranged may also be used. [Explanation of symbols]

[0067] 1...autonomous mobile robot, 10...movement path, 20...robot body, 20C...identification area, 20L...drive wheel, 20R...drive wheel, 21...signpost detection unit (image processing device), 22...drive unit, 23...control unit, 24...communication unit, 25...illumination unit, 26...imaging unit, 27...calculation unit, 28...motor control unit, 29...motor, C...detected unit, C10...detected area, C10a...start bar (first area), C10b...stop bar (second area), C11...cell, C12...cell, C13...cell, C20...identification area, C21...cell, C22...cell, C23...cell, C31...cell, C32...cell, C33...cell, C20...identification area, SC1...first scan, SC2...second scan, SP...signpost (sign)

Claims

1. An image processing device that detects a detection target portion arranged on a two-dimensional plane, the image processing device including a first cell capable of reflecting detection light and a second cell not capable of reflecting the detection light, the detection target portion has an identification area for the image processing device to identify the detection target portion, a calculation unit that calculates a tilt of the detection target portion based on a first relative displacement amount in a secondary direction perpendicular to the primary direction of two of the first cells aligned in the primary direction in the detection target portion and a second relative displacement amount in the primary direction of two of the first cells aligned in the secondary direction, The calculation unit is calculating the first displacement amount based on distances from detection coordinates of two of the first cells aligned in the primary direction to boundaries between the two first cells and two of the second cells arranged on an opposite side of the identification area in the secondary direction, an image processing device that calculates the second displacement amount based on the distance from the detection coordinates of two of the first cells aligned in the secondary direction to the boundaries, in the primary direction, of the two first cells and two of the second cells arranged on the opposite side of the identification area.

2. the detection target portion has a detection target area for the image processing device to detect the detection target portion, 2. The image processing device according to claim 1, wherein the calculation unit detects the detection area by scanning in at least one of the primary direction and the secondary direction, and calculates a slope of the detection area from the first cell included in the detection area.

3. the detection area includes a first area detected by scanning in the primary direction and a second area detected by scanning in the secondary direction and partially overlapping the first area, The image processing device described in claim 2, characterized in that the calculation unit calculates the inclination of the detected portion based on the first displacement amount relative to the first cell arranged in an area where the first area and the second area overlap and another first cell included in the first area, and the second displacement amount relative to the first cell arranged in an area where the first area and the second area overlap and another first cell included in the second area, in the primary direction.

4. the detection area includes a first area detected by scanning in the primary direction, and a second area detected by scanning in the primary direction and disposed at a different position in the secondary direction from the first area, The image processing device described in claim 2, characterized in that the calculation unit calculates the inclination of the detected portion based on the first displacement amount in the secondary direction of the first cell arranged at one end of the first region and another first cell included in the first region, and the second displacement amount in the primary direction of the first cell arranged at one end of the first region and the first cell arranged at one end of the second region.

5. An image processing device as described in any one of claims 1 to 4, characterized in that the calculation unit corrects the direction in which the identification area is scanned based on the inclination of the detected portion.

6. An autonomous mobile robot that reads a sign having a detection part in which a plurality of cells are arranged on a two-dimensional plane with an imaging unit mounted thereon, and moves while being guided by the sign, An autonomous mobile robot comprising the image processing device according to any one of claims 1 to 5.

Images