Mobile body

Abstract

To provide a mobile body with sensors and a load-carrying platform, in which the loading capacity of the load-carrying platform is ensured and a sensor detection range is also ensured.SOLUTION: A mobile body 1 includes: a carriage 10 capable of autonomous movement; a load-carrying platform 20 provided at a prescribed interval on an upper side of the carriage 10; a support body 19 provided between the carriage 10 and the load-carrying platform 20 and fixing the load-carrying platform 20 to the carriage 10; and two distance-measuring sensors 30A and 30B provided between the carriage 10 and the load-carrying platform 20. In the mobile body 1, the two distance-measuring sensors 30A and 30B are arranged with the support body 19 interposed therebetween.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a moving body capable of transporting articles.

Background Art

[0002] Conventionally, so-called autonomous moving bodies that autonomously travel and transport articles are known. Such moving bodies are equipped with sensors such as those for measuring the distance to an object in order to detect the surrounding environment, and the moving body identifies its own position by comparing the acquired information on the surrounding environment with the map information stored in advance.

[0003] A sensor for measuring the distance to an object measures the distance based on, for example, the time from when a laser beam is irradiated until it is reflected back from the object. At this time, errors may occur in the distance measurement due to various factors such as the shape of the object and the material of the surface, or abnormal values that deviate significantly from the ideal value may occur. Therefore, Patent Document 1 provides a moving body capable of accurately calibrating the displacement of the sensor with respect to the carriage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A moving body for transporting articles may include a loading platform for mounting the articles. In a moving body equipped with a loading platform, if a sensor is provided on the loading platform, the loading capacity of the loading platform will decrease by the amount occupied by the sensor. Note that Patent Document 1 does not include a loading platform.

[0006] From the above, an object of the present invention is to ensure the loading capacity of the loading platform while ensuring the detection range of the sensor in a moving body equipped with a sensor and a loading platform.

Means for Solving the Problem

[0007] The mobile body of the present invention is a cart capable of autonomous movement, a loading platform provided at a predetermined interval above the cart, a support provided between the cart and the loading platform for fixing the loading platform to the cart, and two distance measuring sensors provided between the cart and the loading platform. In the mobile body of the present invention, at least two distance measuring sensors are arranged with the support interposed therebetween.

[0008] In the mobile body of the present invention, it is preferable that the two sensors are arranged at symmetric positions with respect to the support.

[0009] In the mobile body of the present invention, it is preferable that the support has a rectangular, particularly square, outer shape in plan view and one diagonal of the rectangle is oriented in the front-rear direction of the mobile body. In this case, the two sensors are arranged on the extension line of one diagonal.

Advantages of the Invention

[0010] According to the present invention, since the distance measuring sensor is provided between the cart and the loading platform, even if the distance measuring sensor is provided, the area for placing an object on the loading platform is not reduced. Further, according to the present invention, since the two distance measuring sensors are arranged with the support interposed therebetween, it is possible to minimize the reduction in the detection range of each distance measuring sensor due to the presence of the support.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

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Mode for Carrying Out the Invention

[0012] Hereinafter, the moving body 1 according to the embodiment of the present invention will be described with reference to the accompanying drawings. The moving body 1 includes a carriage 10, a loading platform 20 provided above the carriage 10, and two LiDARs 30A and 30B as distance measurement sensors provided between the carriage 10 and the loading platform 20. As an example, the loading platform 20 is fixed to and supported by the carriage 10 by a support 19 integrally provided on the carriage 10, and the LiDARs 30A and 30B are arranged with the support 19 interposed therebetween. Note that LiDAR is an abbreviation of Light Detection And Ranging, which is a technology that irradiates laser light and measures the distance to an object and the shape of the object based on the information of the reflected light.

[0013] Since the LiDARs 30A and 30B are provided between the carriage 10 and the loading platform 20 in the moving body 1, the mounting surface 21 of the loading platform 20 is not restricted by the LiDARs 30A and 30B, so the mounting capacity of the loading platform 20 is not reduced. Further, according to the moving body 1, since the two LiDARs 30A and 30B are arranged with the support 19 interposed therebetween, it is possible to minimize the decrease in the detection range of each of the LiDARs 30A and 30B due to the presence of the support 19.

[0014] [Carriage 10: Refer to FIGS. 1 and 2] The carriage 10 is responsible for the autonomous driving of the moving body 1. The carriage 10 includes a vehicle body 11 and, as an example, wheels 17A, 17B, 17C provided below the vehicle body 11, and realizes movements such as forward movement, backward movement, and turning. The carriage 10 includes a drive source for the wheels 17A, 17B, 17C, a controller that controls the operation of the drive source according to the results of distance measurement by the LiDARs 30A, 30B, etc. Since known configurations can be adopted for these moving mechanisms, detailed descriptions are omitted. Note that the number of wheels is not limited to three, and may be four or more.

[0015] The vehicle body 11 has a rectangular parallelepiped appearance, and its top plate 13, which is the upper surface thereof, forms a rectangle in plan view. In the vehicle body 11, as shown in FIG. 1 etc., a front direction (F), a rear direction (R), a longitudinal direction (L), a width direction (W), and a height direction (H) are defined.

[0016] A support 19 is integrally provided at substantially the center in the longitudinal direction (L) and the width direction (W) of the top plate 13. The support 19 has a rectangular outer shape in plan view that protrudes in the height direction (H) from the top plate 13. One of the two diagonal lines D1, D2 of the support 19 (diagonal line D1) extends in the longitudinal direction (L), and the other (diagonal line D2) extends in the width direction (W). As an example, the diagonal line D1 forms a bisector in the width direction (W) of the top plate 13, and the diagonal line D2 forms a bisector in the longitudinal direction (L) of the top plate 13. Note that here, the support 19 shows an example of being integrally formed with the top plate 13, that is, the vehicle body 11, but it may be manufactured separately from the vehicle body 11 and fixed to the top plate 13, or may be integrally formed with the loading platform 20.

[0017] [Loading platform 20: Refer to FIGS. 1 and 2] The loading platform 20 has a mounting surface 21 on its upper surface, and articles (not shown) to be transported by the moving body 1 are placed on this mounting surface 21. The mounting surface 21 has, as an example, a rectangular planar shape similar to that of the top plate 13 and has a planar area substantially equivalent to that of the top plate 13. However, this planar shape and planar area are merely examples. Depending on the shape, dimensions, etc. of the article to be conveyed, other planar shapes such as polygons like triangles or ellipses may be selected, or a planar area larger or smaller than that of the top plate 13 may be selected.

[0018] Since the loading platform 20 is supported and fixed to the support 19, a predetermined interval G is provided between the loading platform 20 and the top plate 13 except for the portion of the support 19, and the LiDARs 30A and 30B are arranged in this interval G. That is, the LiDARs 30A and 30B are provided inside the peripheries of the vehicle body 11 and the loading platform 20, and even if the carriage 10 collides with some object, they will not receive a direct impact.

[0019] [Refer to FIGS. 1 and 2 for LiDARs 30A and 30B] The two LiDARs 30A and 30B are examples of sensors that measure the distance to objects existing around the moving body 1. Since the same type can be applied to both LiDAR 30A and LiDAR 30B, when there is no particular need to distinguish between them in the following description, the two lidar scanners are also collectively referred to as "LiDAR 30".

[0020] LiDAR 30 irradiates laser light, for example, parallel to the main surface of the carriage 10, and performs distance measurement based on the time from irradiation until the light is reflected back from the object. LiDAR 30 has, for example, a measurement range with a predetermined radius (e.g., about 10 m), and while scanning the laser light over a predetermined visual field angle (e.g., about 360 degrees) at a predetermined angular pitch (e.g., about 0.2 to 0.5 degrees), it acquires measurement values of several hundred to several thousand points per scan.

[0021] Two LiDARs 30A and 30B are located on the extension line of the diagonal D1 in the longitudinal direction (L) of the support 19 of the carriage 10, and are respectively provided in the front (F) and the rear (R) sandwiching the support 19. That is, the two LiDARs 30A and 30B are arranged at symmetric positions with respect to the support 19. Thereby, the respective fields of view FV1 and FV2 of the two LiDARs 30A and 30B can be made equal. When the acquired data from the two LiDARs 30A and 30B are combined, ranging in a wide range of azimuths as seen from the carriage 10 becomes possible. The mobile body 1 measures the surrounding environment using the LiDAR 30, thereby creating an environmental map of the surrounding environment, estimating its own position of the mobile body 1 by collating with pre-stored map information, making a route plan, and autonomously moving to the destination while avoiding obstacles. In FIG. 2, FV1 indicates the range in which ranging is possible by the LiDAR 30A, and FV2 indicates the field of view range in which ranging is possible by the LiDAR 30B.

[0022] Note that the LiDAR 30 is an example of a sensor for sensing the surrounding environment of the transport vehicle. Such a sensor is not limited to a laser scanner, and may be any sensor that can measure the distance to an object, such as an ultrasonic sensor, a distance sensor using microwaves, or a distance sensor using a stereo image captured by a stereo camera.

[0023] Also, in the present embodiment, the mobile body 1 is provided with two LiDARs 30A and 30B, but the number of sensors provided in the transport vehicle may be three or more.

[0024] [Effects achieved by the mobile body 1] [First effect: Ensuring the mounting area on the loading platform 20] Since the mobile body 1 arranges the LiDARs 30A and 30B at the interval G between the top plate 13 of the vehicle body 11 and the loading platform 20, providing the LiDARs 30A and 30B does not reduce the loading area of the conveyed objects on the loading platform 20. Therefore, according to the mobile body 1, the planar area of the loading platform 20 can be ensured as the loading area without omission. Moreover, it is not necessary to secure the space above the loading platform 20 for sensing by the LiDARs 30A and 30B, and other devices 40 necessary for the autonomous driving of the mobile body 1 can be provided above the loading platform 20.

[0025] <Second effect: Sensing range by LiDARs 30A and 30B: Refer to Fig. 2> The sensing range in the mobile body 1 that concentrates the support 19 inside the sensing fields of view of the LiDARs 30A and 30B will be described. This sensing range is the range in the horizontal direction. Due to the presence of the support 19, the respective sensing ranges of the LiDARs 30A and 30B are restricted. For the LiDAR 30A arranged in the front (F), the 90° range of the corner in front (F) of the support 19 becomes a blind spot, but the field of view FV1 in the 270° range excluding that can be sensed. For the LiDAR 30B arranged in the rear (R), the 90° range of the corner in the rear (R) of the support 19 becomes a blind spot, but the field of view FV2 in the 270° range excluding that can be sensed. That is, according to the LiDARs 30A and 30B, sensing in the 360° range outside the vehicle body 11 is possible, improving the safety and control stability during the autonomous driving of the mobile body 1. Note that the 90° blind spot and 270° field of view are just examples, and the blind spot and field of view can be other angles depending on the dimensions of the vehicle body 11 and the like.

[0026] <Third effect: Sensing of objects at very close range; Refer to Figs. 4 and 5> By equipping the mobile body 1 with two LiDARs 30A and 30B, the influence of the blind spot (occlusion) caused by obstacles can be reduced in the shape measurement of an object (object to be measured) at a very close range. For example, as shown in FIG. 4, each of the LiDARs 30A and 30B can simultaneously measure both the front surface 101A and the back surface 101B of the object 101 to be measured. Also, as shown in FIG. 5, while the LiDAR 30A is measuring the object 102 to be measured, the blind spot behind the object 102 as viewed from the LiDAR 30A can be scanned by the LiDAR 30B.

[0027] <Fourth Effect: Ensuring the Safety of LiDARs 30A and 30B> The LiDARs 30A and 30B are provided between the vehicle body 11 and the loading platform 20 and are set closer to the inside of the fuselage. Therefore, according to the moving body 1, even if the vehicle body 11 collides with surrounding objects, the LiDARs 30A and 30B are only indirectly impacted, so they are less likely to be damaged. Also, even if the moving body 1 autonomously drives in rainy weather, the LiDARs 30A and 30B are less likely to be covered by rain. In addition, there is a minimum measurable distance for LiDARs where distance measurement becomes impossible when the distance to the object to be measured is too close. The LiDARs 30A and 30B are provided inside the peripheries of the vehicle body 11 and the loading platform 20, and it is possible to make them less affected by the minimum measurable distance of the LiDAR when measuring the distance of an object.

[0028] As described above, the preferred embodiments have been explained. However, as long as the gist of the present invention is not deviated from, it is possible to select and choose the configurations mentioned in the above embodiments or appropriately change them to other configurations. As described above, for the rectangular support 19, the diagonal D1 extends in the longitudinal direction (L) and the diagonal D2 extends in the width direction (W), but the present invention is not limited to this. The diagonal D1 may be parallel to the longitudinal direction (L) and the diagonal D2 may be parallel to the width direction (W). Also, the support 19 is not limited to a rectangle and can be made into other shapes such as a circle or a polygon. Furthermore, although an example in which the two LiDARs 30A and 30B are arranged at the target positions with reference to the support 19 has been described, the present invention is not limited to this, and they may be arranged at asymmetric positions. Even in the above examples, the first effect described above can be achieved.

Description of Symbols

[0029] 1 Moving body 10 Cart 11 Vehicle body 13 Top plate 17A, 17B, 17C Wheels 19 Support 20 Loading platform 21 Mounting surface 30A, 30B LiDAR (Distance measuring sensor) 40 Equipment D1, D2 Diagonal lines G Interval FV1, FV2 Field of view

Claims

1. A cart capable of autonomous movement, A loading platform provided at a predetermined interval above the cart, A support provided between the cart and the loading platform for fixing the loading platform to the cart, Two distance measuring sensors provided between the cart and the loading platform, and A moving body in which the two distance measuring sensors are arranged with the support therebetween.

2. The two distance measuring sensors Are arranged at symmetric positions with respect to the support, The moving body according to Claim 1.

3. The support has a rectangular outer shape in plan view, one diagonal of the rectangle is oriented in the front-rear direction of the moving body, and the two distance measuring sensors are arranged on the extension line of one of the diagonals, The moving body according to Claim 1 or Claim 2.

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