Movable body

Abstract

A scanner (12a) is disposed on the bottom side, of a movable body (1), facing a floor surface, and repeatedly creates, as a first floor surface image, a line image that is perpendicular to the travel direction of the movable body (1) and that has a predetermined width. A controller controls a drive device so as to reduce the deviation between a predetermined route and the current position, of the movable body (1), detected on the basis of the first floor surface images such that the movable body 1 travels on the route. Casters 11, including driven wheels that come into contact with the floor surface, and the scanner 12a are fixed to a frame body 13.

Description

Mobile

[0001] The present invention relates to a moving body.

[0002] One mobile device is equipped with a moving means for moving the device along the surface of a structure, a photographing means provided on the bottom of the device for photographing the surface of the structure, and an identification means for identifying the position of the device by comparing image data output from the photographing means with matching data for each position registered in advance (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-185465

[0004] However, with the above-mentioned mobile device, the mobile device may deform along the shape of the floor due to its own weight, etc., changing the distance from the floor (surface of the structure) to the bottom of the mobile device. If the floor (surface of the structure) falls outside the depth of field of the imaging means, the captured image may become blurred, and the current position of the mobile device may not be accurately determined.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a mobile body whose current position can be accurately identified.

[0006] The present invention relates to a mobile body that includes a drive unit that generates a driving force for traveling, a scanner that optically scans a floor surface to generate a first floor image, a controller that controls the drive unit so that the mobile body travels along a predetermined path while reducing the deviation between the current position of the mobile body detected based on the first floor image and the predetermined path, a frame body with a frame structure, and casters with driven wheels that contact the floor surface. The scanner (a) is disposed on the bottom side of the mobile body facing the floor surface, and (b) repeatedly generates a line image of a predetermined width perpendicular to the direction of travel of the mobile body as the first floor image. The casters and the scanner are fixed to the frame body.

[0007] According to the present invention, a mobile object whose current position can be accurately identified is obtained.

[0008] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0009] FIG. 1 is a perspective view showing a moving body according to an embodiment of the present invention. FIG. 2 is a perspective view showing the mechanical configuration of the moving body shown in FIG. 1. FIG. 3 is a diagram showing the configuration of a scanner in the moving body according to embodiment 1. FIG. 4 is a perspective view showing the electrical configuration of the moving body shown in FIG. 1. FIG. 5 is a diagram showing an example of a floor surface. FIG. 6 is a diagram showing the configuration of a scanner in the moving body according to embodiment 2. FIG. 7 is a diagram showing another example of a floor surface. FIG. 8 is a side view showing a moving body according to embodiment 4.

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

[0011] Embodiment 1.

[0012] Fig. 1 is a perspective view showing a moving body according to an embodiment of the present invention, and Fig. 2 is a perspective view showing the mechanical configuration of the moving body shown in Fig. 1.

[0013] The mobile body 1 shown in Fig. 1 is a self-propelled mobile body, such as an automatic guided vehicle (AGV), an autonomous mobile robot (AMR), etc. As shown in Fig. 2, the mobile body 1 includes four casters 11 installed at the four corners of the bottom surface, scanners 12a and 12b, and a frame body 13 to which the casters 11 and the scanners 12a and 12b are fixed.

[0014] The caster 11 has a driven wheel that comes into contact with the floor surface and is fixed to the frame body 13 so as to be freely rotatable.

[0015] The scanner 12a optically scans the floor surface to generate a first floor surface image. The scanner 12a is disposed at the leading end of the mobile object 1 in the traveling direction. The scanner 12b optically scans the floor surface to generate a second floor surface image. The scanner 12b is disposed at the trailing end of the mobile object 1 in the traveling direction.

[0016] Each scanner 12a, 12b (a) is arranged on the bottom side of the moving body 1 facing the floor surface, and (b) repeatedly generates a line image of a predetermined width perpendicular to the direction of travel of the moving body 1 as a first floor image or a second floor image.

[0017] The scanners 12a and 12b scan the floor surface at a predetermined high resolution (for example, 600 dpi).

[0018] The frame body 13 is a body having a frame structure. For example, the frame body 13 is formed from a metal pipe such as a steel pipe. For example, as shown in FIG. 2 , the casters 11 and the scanners 12 a and 12 b are fixed to the bottom surface of the frame body 13.

[0019] Furthermore, the moving body 1 is provided with drive wheel units 21a, 21b, 21c, and 21d.

[0020] Each drive wheel unit 21a, 21b, 21c, 21d includes a drive wheel 31 that contacts the floor surface, a support portion 32 that supports the drive wheel 31 so that it can rotate freely, a wheel frame portion 33 to which the support portion 32 is fixed, a rotational support portion 34 that fixes one end of the wheel frame portion 33 to the frame body 13 (one of the beams 13a, 13b) so that it can rotate freely, and a spring member 35 that biases the other end of the wheel frame portion 33 against the frame body 13 (the other of the beams 13a, 13b).

[0021] As a result, the restoring force of the spring member 35 presses the drive wheel 31 against the floor surface with a predetermined pressure.

[0022] Furthermore, each of the drive wheel units 21a, 21b, 21c, and 21d includes a drive device (not shown) that generates and transmits driving force for running to the drive wheels 31. The drive devices are installed independently for each of the drive wheel units 21a, 21b, 21c, and 21d, and individually generate and transmit driving force to the drive wheels 31. Here, the drive devices generate driving force using a motor and transmit the driving force to the drive wheels 31 using gears or the like. The drive wheels 31 include, for example, a drive shaft connected to the drive device, a hard wheel fixed to the drive shaft, and an elastic tire fitted on the outside of the wheel.

[0023] FIG. 3 is a diagram showing the configuration of a scanner in a moving body according to the first embodiment.

[0024] In embodiment 1, as shown in FIG. 3, each scanner 12a, 12b includes a light-emitting unit (not shown) that irradiates light onto the floor surface, an image sensor 41, and a reduction optical system 42 (one or more lenses) that focuses reflected light obtained when the light from the light-emitting unit is reflected by the floor surface onto the image sensor 41.

[0025] Fig. 4 is a perspective view showing the electrical configuration of the moving body shown in Fig. 1. As shown in Fig. 4, the moving body 1 includes, in addition to the drive device 51 described above, a power supply device 52, a communication device 53, and a controller 54.

[0026] The power supply device 52 may include, for example, a built-in secondary battery, and supplies power to the drive device 51, the communication device 53, and the controller 54. The power supply device 52 may be connected to a commercial power source and may include a charging circuit for charging the secondary battery. The secondary battery may also be detachable.

[0027] The communication device 53 performs data communication with an external device (such as a server) via wireless communication in accordance with a predetermined communication protocol.

[0028] The controller 54 includes a computer and an ASIC (Application Specific Integrated Circuit), and performs data processing, control of the drive device 51, control of the communication device 53, etc. using the computer (software processing) and the ASIC (hardware processing).

[0029] The controller 54 controls the drive device 51 so that the moving object 1 travels along the route while reducing the deviation between the route and the current position of the moving object 1 detected based on the first floor image (here, the first floor image and the second floor image). Furthermore, the controller 54 stops the moving object 1 at a predetermined position (the end or midpoint of the route) based on the current position of the moving object 1 detected based on the first floor image.

[0030] In the first embodiment, the controller 54 detects a deviation between the current position of the moving object 1 and the path based on the first floor image. FIG. 5 is a diagram showing an example of a floor. For example, as shown in FIG. 5, linear markers 111 (such as tape) indicating the path and markers 111a indicating stop positions are placed on the floor 101. The controller 54 then detects edges of the images of the markers 111 in the first floor image, derives a deviation from the path in a direction perpendicular to the traveling direction based on the position of the edge in the first floor image, and derives the inclination of the traveling direction with respect to the path based on the inclination of the edge, and controls the drive device 51 to reduce the deviation and inclination.

[0031] If the rotational speed of the drive wheels 31 of drive wheel units 21a and 21b and the rotational speed of the drive wheels 31 of drive wheel units 21c and 21d are made the same, the mobile body 1 will move straight, but if the rotational speed of the drive wheels 31 of drive wheel units 21a and 21b and the rotational speed of the drive wheels 31 of drive wheel units 21c and 21d are made different from each other, the mobile body 1 will turn. Therefore, the drive devices 51 of each drive wheel unit 21a, 21b, 21c, and 21d are controlled to reduce the above-mentioned deviation and tilt.

[0032] Furthermore, the inclination of the traveling direction with respect to the route may be derived based on the deviation obtained from the first floor image and the deviation obtained from the second floor image.

[0033] Furthermore, when the controller 54 detects the image of the marker 111a in the first floor image by pattern matching or the like, it controls the driving device 51 to stop the moving body 1.

[0034] Next, the operation of the moving body according to the first embodiment will be described.

[0035] In the moving body 1, when the controller 54 detects a user operation on an input device (such as a switch) not shown, or receives a start command via the communication device 53, it controls the drive device 51 to start the moving body 1.

[0036] Then, scanner 12a (and scanner 12b) repeatedly generates the line image as a first floor image (and second floor image), and controller 54 identifies the deviation of the current position of moving body 1 relative to the route based on the first floor image (and second floor image), controls drive device 51 to reduce the deviation, and allows moving body 1 to continue traveling.

[0037] Furthermore, when the controller 54 determines based on the first floor image (and the second floor image) that the current position of the moving body 1 is a stopping position, it stops the drive device 51 to stop the moving body 1.

[0038] As described above, according to the first embodiment, the scanner 12a (a) is disposed on the bottom side of the moving object 1 facing the floor surface 101, and (b) repeatedly generates, as a first floor image, a line image of a predetermined width perpendicular to the traveling direction of the moving object 1, and the controller 54 controls the drive device 51 so that the moving object 1 travels on the predetermined path by reducing the deviation between the current position of the moving object 1 detected based on the first floor image. The casters 11 equipped with driven wheels that come into contact with the floor surface and the scanner 12a are fixed to the frame body 13.

[0039] As a result, the casters 11 and scanner 12a are fixed to a highly rigid frame body 13, the distance from the floor surface that the casters 11 come into contact with to the scanner 12a hardly changes, and the floor surface is unlikely to fall outside the depth of field of the scanner 12a, so that an image of the floor surface directly below the moving body 1 can be obtained with good high resolution, and the moving body 1 can be stopped accurately at the desired position.

[0040] Embodiment 2.

[0041] Fig. 6 is a diagram showing the configuration of a scanner in a moving body according to embodiment 2. In embodiment 2, scanners 12a and 12b include contact image sensors, as shown in Fig. 6. That is, in embodiment 2, scanners 12a and 12b are scanners with a life-size optical system that include a line sensor 41a including a plurality of light-receiving elements and a lens array 42a.

[0042] The other configurations and operations of the moving body according to the second embodiment are the same as those of the first embodiment, and therefore the description thereof will be omitted.

[0043] Embodiment 3.

[0044] In the third embodiment, the communication device 53 (a) transmits a first floor image (image data) to a predetermined server in response to a request from the controller 54, and receives from the server a deviation between the current position of the moving object 1 and the route, or a control amount corresponding to the deviation, detected by the server based on the first floor image. Then, the controller 54 controls the driving devices 51 so that the moving object 1 travels along the route, based on the received deviation or control amount (control amount of each driving device 51).

[0045] In the third embodiment, the server stores a floor image of the entire floor surface 101 (i.e., the range of movement of the mobile body 1), and identifies the position of a first floor image (i.e., a partial floor image transmitted from the mobile body 1) in the floor image by pattern matching or the like, and identifies the actual current position corresponding to that position. Furthermore, the server stores route information of the mobile body 1, and identifies the deviation between the route based on that route information and the current position, and transmits that deviation or the corresponding control amount to the mobile body 1. Here, a line image with a predetermined number of lines is transmitted to the server as the first floor image.

[0046] Furthermore, if the derived current position matches a preset stop position, the server sends a stop command to the mobile body 1, and when the stop command is received by the communication device 53 of the mobile body 1, the controller 54 stops the drive device 51 and stops the mobile body 1.

[0047] 7 is a diagram showing another example of a floor surface. For example, the floor surface 101 has scratches, stains, etc. in addition to the original pattern 112 (i.e., the pattern of the surface of the floor material such as tile or concrete), so the image pattern varies depending on the position in the high-resolution floor image. Therefore, the current position of the moving object 1 can be identified based on the first floor image.

[0048] Here, the first floor image is sent to the server, but in a similar manner, the first floor image and the second floor image may be sent to the server, and the current position may be derived in a similar manner for each of the first floor image and the second floor image.

[0049] The first floor image (and the second floor image) may be compressed in the mobile object 1 and then transmitted to the server, where the data may be expanded.

[0050] Furthermore, without using the above-mentioned server, the mobile body 1 may store a floor image of the entire floor surface 101 (i.e., the range of movement of the mobile body 1), and the position of the first floor image in that floor image may be identified by pattern matching or the like, and the actual current position corresponding to that position may be identified.

[0051] The other configurations and operations of the moving body according to the third embodiment are the same as those of the first or second embodiment, and therefore the description thereof will be omitted.

[0052] Embodiment 4.

[0053] 8 is a side view showing a moving body according to a fourth embodiment. In the fourth embodiment, the moving body 1 includes a housing 1a that protrudes forward from the casters 11 and the scanner 12a, an infrared sensor 81 for preventing collisions, and a main switch 82. The infrared sensor 81 and the main switch 82 are disposed at the front end of the housing 1a, for example, as shown in FIG. 8. When the infrared sensor 81 detects an obstacle or the like, the controller 54 brings the moving body 1 to an emergency stop.

[0054] For example, as shown in FIG. 8, the housing 1a protrudes forward from the scanner 12a, so that external light is less likely to enter the scanner 12a.

[0055] The other configurations and operations of the moving body according to the fourth embodiment are the same as those of any of the first to third embodiments, and therefore the description thereof will be omitted.

[0056] It should be noted that various changes and modifications to the above-described embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the subject matter and without diminishing its intended advantages. In other words, it is intended that such changes and modifications be included within the scope of the claims.

[0057] For example, in the above embodiment, the scanner 12b does not need to be provided.

[0058] The present invention is applicable to, for example, a moving body.

Claims

1. In a mobile object, a drive device that generates a driving force for traveling; a scanner that optically scans a floor surface to generate a first floor surface image; a controller that controls the drive device so that the moving object travels along a predetermined path by reducing a deviation between the current position of the moving object detected based on the first floor image and the predetermined path; Frame body with frame structure, a caster having a driven wheel that contacts the floor surface; a communication device; The scanner (a) is disposed on a bottom surface side of the moving body facing the floor surface, and (b) repeatedly generates a line image of a predetermined width perpendicular to a direction of travel of the moving body as the first floor surface image, the casters and the scanner are fixed to the frame body; The communication device (a) transmits the first floor image to a predetermined server, and receives a deviation between the current position of the moving object and the route, or a control amount corresponding to the deviation, detected by the server based on the first floor image; the controller controls the drive device based on the deviation or the control amount so that the moving body travels along a predetermined path; A mobile object characterized by:

2. 2. The mobile body according to claim 1, wherein the scanner comprises a light-emitting unit, an image sensor, and a reduction optical system that focuses reflected light obtained when light from the light-emitting unit is reflected on the floor surface onto the image sensor.

3. 2. The vehicle of claim 1, wherein the scanner comprises a contact image sensor.

4. 2. The moving body according to claim 1, wherein the controller detects a deviation between the current position of the moving body and the route based on the first floor image.

5. a rear end scanner disposed at a rear end portion of the moving body in the traveling direction, the rear end scanner optically scanning the floor surface to generate a second floor surface image; the scanner is disposed at a tip portion of the moving body in the traveling direction, the rear end scanner repeatedly generates a line image of a predetermined width perpendicular to a direction of travel of the moving object as the second floor image; the controller controls the drive device so that the moving object travels on the path by reducing a deviation between the path and a current position of the moving object detected based on the first floor image and the second floor image; 2. The moving body according to claim 1, wherein:

6. 2. The mobile body according to claim 1, further comprising a housing protruding forward from the casters and the scanner, and an infrared sensor for preventing collisions, disposed at a tip of the housing.