Moving body

Abstract

To reduce a load when a moving body gets over a step.SOLUTION: A moving body comprising a first rotating body and a second rotating body that move while rotating on a traveling surface, wherein a rotation center of the first rotating body and a rotation center of the second rotating body are separated from each other in a first direction in which the moving body travels, and the first rotating body and the second rotating body are arranged to overlap each other when the first rotating body and the second rotating body are viewed from a second direction along the traveling surface and orthogonal to the first direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, mobile objects with wheels have become widespread. For example, Patent Document 1 discloses a wheelchair with front and rear wheels. The wheelchair has a telescopic actuator that raises and lowers the wheelchair body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-180757 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the wheelchair disclosed in Patent Document 1, when the wheelchair reaches a step, the actuator raises and lowers the wheelchair, allowing the wheelchair to overcome the step. However, the wheelchair disclosed in Patent Document 1 is equipped with an actuator for dealing with steps, which poses a cost issue. In particular, when the wheelchair is used in areas where there are no steps, there is no advantage to the actuator, so it is desirable to reduce the cost of the mechanism for dealing with steps.

[0005] In addition, mobile bodies that run without human power can overcome steps by enlarging the wheels and increasing the torque of the driving means (for example, an engine or motor), but this poses challenges in terms of cost, size, and heat dissipation.

[0006] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a technology that can reduce the load when a moving object goes over a step. [Means for solving the problem]

[0007] In order to solve the above problem, according to one aspect of the present invention, there is provided a moving body having a first rotating body and a second rotating body that move while rotating on a running surface, wherein the center of rotation of the first rotating body and the center of rotation of the second rotating body are spaced apart in a first direction in which the moving body runs, and when the first rotating body and the second rotating body are viewed from a second direction along the running surface that is perpendicular to the first direction, the first rotating body and the second rotating body are arranged so that they overlap each other.

[0008] The first rotating body and the second rotating body may be provided in different position ranges in the second direction.

[0009] The first rotating body and the second rotating body may be provided in different positional ranges in a third direction perpendicular to the first direction and the second direction.

[0010] The moving body may further include an elastic body that elastically deforms so that the first rotating body rises in the height direction when a force equivalent to a predetermined weight is applied to the first rotating body from the gravity direction side.

[0011] The moving body may further include a limiting mechanism that limits a maximum amount of lift of the first rotating body due to elastic deformation of the elastic body.

[0012] When the first rotating body is raised to its maximum extent, the first rotating body and the second rotating body may be arranged so as to overlap each other when viewed from the second direction.

[0013] The predetermined weight may be equal to or less than a weight applied to the first rotating body when the moving body is supported by rotating bodies other than the second rotating body. [Effects of the Invention]

[0014] According to the present invention as described above, it is possible to reduce the load when a moving body goes over a step. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an explanatory diagram showing the appearance of a vehicle 10 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a rear view showing the wheel unit 200 as seen from the rear. [Figure 3] 10 is an explanatory diagram showing the process in which the wheel unit 200 goes over a step. FIG. [Figure 4] 10 is an explanatory diagram showing the process in which the wheel unit 200 goes over a step. FIG. [Figure 5] 10 is an explanatory diagram showing a moment generated when a wheel V goes over a step. FIG. [Figure 6] FIG. 1 is a side view of a vehicle 12 according to a second embodiment of the present invention. [Figure 7] FIG. 2 is a rear view of a vehicle 12 according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a side view of a wheel unit 400 according to a second embodiment of the present invention. [Figure 9] 10 is an explanatory diagram showing the process in which the vehicle 12 goes over a step. FIG. [Figure 10] 10 is an explanatory diagram showing the process in which the vehicle 12 goes over a step. FIG. [Figure 11] 10 is an explanatory diagram showing the process in which the vehicle 12 goes over a step. FIG. [Figure 12] 10 is an explanatory diagram showing the process in which the vehicle 12 goes over a step. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0017] An embodiment of the present invention relates to a moving body having a rotating body that moves while rotating on a traveling surface. Examples of the rotating body include wheels and spherical rollers. The moving body may be a moving body without a human on board, or a moving body with a human on board. Furthermore, the moving body may move according to human operation, or may move autonomously.

[0018] Specifically, the mobile body may be a mobile body that moves by human power, such as a cart, wheelchair, or bicycle, or a mobile body that moves based on driving force generated by an engine or motor, such as an automobile, electric bicycle, electric wheelchair, service robot, or AGV (Automated Guided Vehicle).

[0019] In the following, a vehicle having wheels and moving autonomously based on battery power will be mainly described as a moving body according to the first and second embodiments of the present invention.

[0020] First Embodiment (overview) 1 is an explanatory diagram showing the appearance of a vehicle 10 according to a first embodiment of the present invention. As shown in FIG. 1, the vehicle 10 according to the first embodiment of the present invention includes a vehicle body 100, drive wheels 110, and a wheel unit 200.

[0021] -Vehicle body 100 The vehicle body 100 has a housing and various components housed in the housing, such as a battery, an input device, a communication device, a drive device, a control device, and an output device.

[0022] The battery stores power to be supplied to various components of the vehicle 10. The communication device communicates with an external system, an external terminal, or the like.

[0023] The input device acquires environmental information about the surroundings of the vehicle 10. For example, the input device may include a camera and a microphone to acquire video data and audio data about the surroundings of the vehicle 10. The input device may also acquire sensor data used for self-location estimation to detect the position of the vehicle 10 on a map. The sensor data may be video data acquired by a camera or point cloud data acquired by a LiDAR (Light Detection and Ranging) sensor.

[0024] The communication device receives a task execution instruction from an external system. The communication device also transmits to the external system the remaining battery level, environmental information around the vehicle 10 acquired by the input device, and location information of the vehicle 10. Examples of tasks include cleaning, guidance, monitoring, and transporting items. The task may also include information indicating the travel route of the vehicle 10 or information indicating the target location.

[0025] The drive unit generates a drive force that drives the drive wheels 110. The drive unit may be an engine or a motor.

[0026] The control device controls the overall operation of the vehicle 10. For example, the control device estimates the vehicle's own position based on sensor data obtained by the input device. The control device also controls the drive device to drive the vehicle 10. For example, the control device controls the drive device based on the vehicle's own position so that the vehicle 10 moves along a travel route included in the task.

[0027] Such a control device may be configured as hardware such as a dedicated IC (Integrated Circuit) chip, or may be realized by a processor such as a CPU (Central Processing Unit) executing a program. In this case, a computer-readable recording medium on which the program is recorded may also be provided.

[0028] The output device may include a display device that outputs video and a sound output device that outputs sound. For example, the output device may output a melody or sound to notify the surroundings of the presence of the vehicle 10 under control of the control device.

[0029] -Drive wheels 110 The drive wheels 110 rotate based on a driving force generated by a drive unit of the vehicle body 100. The drive wheels 110 are larger than the wheels 210 and 211 described below. In this specification, the longitudinal direction (the X direction shown in FIG. 1) may be used as an example of a first direction. The vehicle 10 travels along the longitudinal direction by the rotation of the drive wheels 110. In particular, the direction in which the drive wheels 110 are located as seen from the wheel unit 200 may be referred to as the forward direction, and the direction opposite to the forward direction may be referred to as the rearward direction. In addition, in this specification, the direction along the traveling surface and perpendicular to the longitudinal direction may be referred to as the width direction (an example of a second direction, the Y direction shown in FIG. 1). That is, FIG. 1 is a side view showing the vehicle 10 as seen from the width direction. In addition, in this specification, the direction perpendicular to the longitudinal direction and the width direction may be referred to as the height direction (an example of a third direction, the Z direction shown in FIG. 1).

[0030] -Wheel unit 200 The wheel unit 200 is a unit having a plurality of wheels. The wheel unit 200 is separated from the drive wheel 110 in the front-rear direction. The wheel unit 200 has an ingenious design to reduce the load when the wheel unit 200 goes over a step. The configuration of the wheel unit 200 will be specifically described below.

[0031] (Configuration of wheel unit 200) 2 is a rear view showing the wheel unit 200. As shown in FIGS. 1 and 2, the wheel unit 200 has a wheel 210, a wheel 211, an axle 220, an axle 221, and a fixing part 230.

[0032] Wheel 210 is an example of a first rotating body that moves while rotating on a running surface. Wheel 211 is an example of a second rotating body. Wheel 210 and wheel 211 may be driving wheels or driven wheels.

[0033] 1, the wheels 210 and 211 are arranged so as to overlap each other in a side view of the wheels 210 and 211. In other words, the wheels 210 and 211 are arranged so close to each other that the outer contours of the wheels 210 and 211 intersect in a side view.

[0034] Furthermore, the wheels 210 and 211 are provided in different position ranges in the height direction. Specifically, the wheels 211 are provided in a position range above the wheels 210.

[0035] Axle 220 is the rotation axis of wheel 210. Axle 221 is the rotation axis of wheel 211. Hereinafter, the central axis of axle 220 may be referred to as the rotation center of wheel 210, and the central axis of axle 221 may be referred to as the rotation center of wheel 211.

[0036] 1, the rotation center of wheel 210 and the rotation center of wheel 211 are spaced apart in the front-to-rear direction. Specifically, the rotation center of wheel 211 is located further forward than the rotation center of wheel 210.

[0037] 2, the wheels 210 and 211 are provided in different position ranges in the width direction. Therefore, the wheels 210 and 211 do not interfere with each other, and the axles 220 and 221 do not interfere with each other.

[0038] The fixing parts 230 fix the axles 220 and 221 to the vehicle body 100 .

[0039] (operation) Next, the operation of the vehicle 10 according to the first embodiment of the present invention will be described with reference to FIGS.

[0040] 3 and 4 are explanatory diagrams showing the process of the wheel unit 200 going over a step. As shown in Fig. 1, when the wheel unit 200 of the vehicle 10 approaches a step, the wheel 211 goes over the step as shown in Fig. 3 based on the driving force of the drive wheel 110. This causes the wheel 210 to become lifted off the traveling surface. From this state, as shown in Fig. 4, the wheel 210 goes over the step, and then the wheel 210 comes down from the step, causing the wheel unit 200 to go over the step.

[0041] (Action and effect) According to the first embodiment of the present invention described above, various operational effects can be obtained. For example, according to the first embodiment of the present invention, it is possible to reduce the load when the vehicle 10 goes over a step. This point will be described in detail with reference to FIG. 5.

[0042] Figure 5 is an explanatory diagram showing the moment generated when wheel V goes over a step. In Figure 5, R is the radius of wheel V, h is the height of the step, and P is the point where wheel V first comes into contact with the step. The height direction length Rz is the length in the height direction between center O of wheel V and point P, and is expressed as "radius R - height of step h" when wheel V is in contact with the riding surface. The front-to-rear direction length Rx is the length in the front-to-rear direction between center O of wheel V and point P. The central angle θ is the angle between the line connecting center O of wheel V and point P and a vertical line.

[0043] The load moment W1 (a moment generated based on the weight on the wheel and gravity (mg)) generated at point P when wheel V goes over a step is expressed as the product of the longitudinal length Rx and the force mg in the direction of gravity. Therefore, the load moment W1 becomes smaller as the longitudinal length Rx becomes smaller (as the central angle θ becomes smaller). In addition, the drive moment W2 generated at point P by the horizontal force F of wheel V is expressed as the product of the height length Rz and the horizontal force F. Therefore, the drive moment W2 becomes larger as the height length Rz becomes larger (as the central angle θ becomes smaller). When the drive moment W2 exceeds the load moment W1, wheel V will go over a step.

[0044] According to the first embodiment of the present invention, when the vehicle 10 is traveling on a horizontal traveling surface, the wheel 211 located on the front side is separated from the traveling surface. Therefore, in the first embodiment of the present invention, when the wheel 211 reaches a step, the length Rx in the front-rear direction is smaller and the length Rz in the height direction is larger than when the wheel 211 reaches a step while in contact with the traveling surface. Therefore, the load moment W1 generated around the point P on the wheel 211 is smaller and the drive moment W2 is larger. As a result, the wheel 211 can climb up the step with a smaller horizontal force F.

[0045] Then, the wheel 210 reaches the step in a state in which the vehicle 10 is lifted by the wheel 211. For this reason, in the first embodiment of the present invention, when the wheel 210 reaches the step, the length Rx in the front-rear direction is smaller and the length Rz in the height direction is larger than when the wheel 210 reaches the step in a state in which the wheel 210 is in contact with the traveling surface. Therefore, the load moment W1 generated around the point P on the wheel 210 is smaller and the drive moment W2 is larger. As a result, the wheel 210 can climb up the step with a smaller horizontal force F.

[0046] If the wheels 210 and 211 are spaced apart in the front-to-rear direction so that they do not overlap in a side view, after the wheels 211 climb up a step, the wheels 211 may descend from the step before climbing up the step. In this regard, according to the first embodiment of the present invention, the wheels 210 and 211 are provided close enough to overlap in a side view, so that the wheels 210 can climb up the step in a state where the vehicle 10 is lifted by the wheels 211 before the wheels 211 descend the step.

[0047] <Second embodiment> Having described the first embodiment of the present invention above, the second embodiment of the present invention will now be described.

[0048] (composition) Fig. 6 is a side view of a vehicle 12 according to a second embodiment of the present invention. Fig. 7 is a rear view of a vehicle 12 according to a second embodiment of the present invention. Fig. 8 is a side view of a wheel unit 400 according to a second embodiment of the present invention.

[0049] 6 and 7, the vehicle 12 according to the second embodiment of the present invention includes a vehicle body 100, a driving wheel 110, an additional unit 300, and a wheel unit 400. The following mainly describes the configuration of the vehicle 12 according to the second embodiment of the present invention that differs from the vehicle 10 according to the first embodiment.

[0050] 6 and 7, the additional unit 300 is connected to the vehicle body 100. Various connecting means may be used to connect the additional unit 300 to the vehicle body 100. Furthermore, the additional unit 300 may be detachable from the vehicle body 100.

[0051] As shown in Fig. 7, the additional unit 300 has two assemblies, each consisting of a wheel 310, an axle 320, and a fixing part 330, spaced apart in the width direction. The wheel 310 is an example of a second rotating body that moves while rotating on the running surface. The axle 320 is the rotation axis of the wheel 310. The fixing part 330 fixes the axle 320 to the additional unit 300. The two wheels 310 are in contact with the running surface while the vehicle 12 is running on a level running surface.

[0052] As shown in Fig. 7, the wheel unit 400 is provided between the two wheels 310 of the additional unit 300. As shown in Fig. 8, the wheel unit 400 has a movable wheel 410, an axle 420, a fixing part 430, a fixing bracket 440, a torsion spring 450, and a limiter 460.

[0053] The movable wheel 410 is an example of a first rotating body that moves while rotating on the travel surface. The movable wheel 410 is located forward of the wheels 310. The axle 420 is the axis of rotation of the movable wheel 410.

[0054] The fixing part 430 fixes the wheel unit 400 to the vehicle body 100. The fixing metal fitting 440 fixes one end of the torsion spring 450 to the axle 420.

[0055] Torsion spring 450 is an example of an elastic body that can be elastically deformed. One end of torsion spring 450 is fixed to fixing bracket 440, and the other end of torsion spring 450 is fixed to fixing part 430. When a force equivalent to a predetermined weight is applied to axle 420 from the gravity direction, torsion spring 450 elastically deforms so that movable wheel 410 rises in the height direction.

[0056] The predetermined weight is a weight that exceeds the weight that would be applied to the movable wheels 410 when the drive wheels 110 and the movable wheels 410 support the portion of the vehicle 12 excluding the additional unit 300. In other words, when the portion is supported by the drive wheels 110 and the movable wheels 410, the torsion spring 450 does not elastically deform. On the other hand, the predetermined weight is equal to or less than the weight that would be applied to the movable wheels 410 when the entire vehicle 12 is supported by the drive wheels 110 and the movable wheels 410 other than the wheels 310. In other words, when the entire vehicle 12 is supported by the drive wheels 110 and the movable wheels 410, the torsion spring 450 elastically deforms, and the movable wheels 410 rise relative to the vehicle body 100.

[0057] Limiter 460 is an example of a limiting mechanism that limits the maximum amount of lift of movable wheel 410 relative to vehicle body 100 due to elastic deformation of torsion spring 450. In the example shown in Fig. 8, one end of limiter 460 is fixed to fixing part 430, and limiter 460 protrudes below fixing part 430. When movable wheel 410 lifts, fixing metal fitting 440 abuts against limiter 460, thereby limiting the maximum amount of lift of movable wheel 410.

[0058] The fixing metal fittings 440, the torsion springs 450 and the limiters 460 may be provided on both sides of the movable wheel 410 as shown in FIG.

[0059] (operation) Next, the operation of the vehicle 12 according to the second embodiment of the present invention will be described with reference to FIGS.

[0060] 9 to 12 are explanatory diagrams showing the process of the vehicle 12 going over a step. For ease of understanding, Fig. 9 to 12 show only a part of the wheel unit 400, the wheel 310 and the axle 320.

[0061] First, when the movable wheel 410 approaches a step as shown in Figure 9, the torsion spring 450 elastically deforms based on the driving force of the drive wheel 110, and the movable wheel 410 rises to a position where the fixing bracket 440 and the limiter 460 abut, as shown in Figure 10.

[0062] 11, when the movable wheel 410 climbs up onto a step while it has risen to a position where the fixing metal fitting 440 and the limiter 460 abut, the wheel 310 is lifted off the running surface. From this state, the wheel 310 climbs up onto the step, and then the wheel 310 descends from the step, as shown in FIG. 12, and the vehicle 12 overcomes the step. Note that, as shown in FIG. 12, after the movable wheel 410 has passed over the step, the elastic force of the torsion spring 450 causes the movable wheel 410 to descend and return to its initial position.

[0063] (Action and effect) The second embodiment of the present invention described above provides a variety of advantageous effects. For example, according to the second embodiment, when the movable wheel 410 is raised to its maximum extent as shown in FIG. 11 , the center of rotation of the movable wheel 410 is located forward of the center of rotation of the wheel 310, the movable wheel 410 is located above the wheel 310, and the movable wheel 410 and the wheel 310 are arranged so as to overlap each other in a side view of the movable wheel 410 and the wheel 310. With this configuration, similar to the first embodiment, the wheel 310 reaches the step while the vehicle 12 is being lifted by the movable wheel 410. Therefore, the load moment W1 generated around the point P described with reference to FIG. 5 on the wheel 310 is reduced, and the drive moment W2 is increased, allowing the wheel 310 to climb up the step with a smaller horizontal force F.

[0064] Furthermore, in the second embodiment of the present invention, the torsion spring 450 is designed not to elastically deform when the additional unit 300 is not connected to the vehicle body 100, but is designed to elastically deform when the movable wheel 410 goes over a step with the additional unit 300 connected to the vehicle body 100. Therefore, when the additional unit 300 is not connected to the vehicle body 100, the vehicle 12 can be used as usual, and when the additional unit 300 is connected to the vehicle body 100, it is possible to achieve the effect of making it easier to go over steps.

[0065] <Conclusion> Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0066] For example, in the first embodiment, an example has been described in which the wheels 211 and 210 are provided at different position ranges in the height direction, but the wheels 211 and 210 may be provided at the same height. In this case, by making the wheels 211 softer than the wheels 210 in terms of material or air volume, it is expected that the same effect as in the first embodiment described above will be achieved. [Explanation of symbols]

[0067] 10 vehicles 100 Vehicle body 110 Drive Wheel 12 vehicles 200 Wheel Unit 210 wheels 211 Axle 220 wheels 221 Axle 230 Fixing parts 300 additional units 310 wheels 320 axle 330 Fixing parts 400 Wheel Unit 410 Movable Wheel 420 axle 430 Fixing parts 440 Fixing bracket 450 torsion spring 460 Limiter

Claims

1. A mobile object, The vehicle has a first rotating body and a second rotating body that move while rotating on a travel surface, a rotation center of the first rotating body and a rotation center of the second rotating body are spaced apart in a first direction in which the moving body travels, A moving body, wherein the first rotating body and the second rotating body are arranged to overlap each other when viewed along the running surface from a second direction perpendicular to the first direction.

2. The moving body according to claim 1 , wherein the first rotating body and the second rotating body are provided in different position ranges in the second direction.

3. 2. The moving body according to claim 1, wherein the first rotating body and the second rotating body are provided in different positional ranges in a third direction perpendicular to the first direction and the second direction.

4. 3. The moving body according to claim 2, further comprising an elastic body that elastically deforms so that the first rotating body rises in the height direction when a force equivalent to a predetermined weight is applied to the first rotating body from the gravity direction side.

5. The moving body according to claim 4 , further comprising a limiting mechanism that limits a maximum amount of lift of the first rotating body due to elastic deformation of the elastic body.

6. 6. The movable body according to claim 5, wherein when the first rotating body is raised to the maximum extent, the first rotating body and the second rotating body are arranged to overlap each other when viewed from the second direction.

7. 7. The moving body according to claim 6, wherein the predetermined weight is equal to or less than a weight applied to the first rotating body when the moving body is supported by rotating bodies other than the second rotating body.

Images