Traveling device

Abstract

The present invention provides a vehicle-mounted vehicle that can prevent tipping backward when the vehicle overcomes an obstacle, using a simple configuration. [Solution] A running device comprising: a track, a drive wheel that provides driving force to the track, and at least two idler wheels positioned below the drive wheel, wherein the track rotates around the drive wheel and the idler wheels to move, and an auxiliary member provided on the upstream side of the running direction of the track, which assists in preventing tipping over, wherein the running direction of the track superior When the road wheels located on the flowing side are in contact with the upper step of a predetermined step of a specific height relative to the running surface via the tracks, and the end of the auxiliary member is in contact with the running surface, the center of gravity of the running device is located downstream in the direction of travel of the tracked running body with respect to the vertical line from the point of contact between the end of the auxiliary member and the running surface.

Description

Technical Field

[0001] The present invention relates to a traveling device.

Background Art

[0002] Conventionally, as one type of mobile robot, a traveling device provided with a crawler-type traveling body that travels by a crawler wound around wheels is known.

[0003] Patent Document 1 discloses a traveling device using a flipper-type crawler, which enables smooth crossing of steps by moving the center of gravity of the main body even when the traction force by the crawler is weak.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, according to Patent Document 1, in order to smoothly cross steps by moving the center of gravity of the main body, a plurality of driving means are required, resulting in a problem of a complicated design.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a traveling device that can prevent backward tipping with a simple configuration when the traveling device crosses a step.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the present invention provides a running device comprising: a track; a drive wheel that provides driving force to the track; and at least two idler wheels positioned below the drive wheel, wherein the track rotates around the drive wheel and the idler wheels to move; and an auxiliary member provided on the upstream side of the running direction of the tracked running device to assist in preventing tipping, wherein when the idler wheel located on the downstream side of the running direction of the tracked running device is in contact with the upper step of a predetermined step of a set height relative to the running surface via the track, and when the end of the auxiliary member is in contact with the running surface, the center of gravity of the running device is located downstream of the running direction of the tracked running device with respect to the vertical line from the point of contact between the end of the auxiliary member and the running surface. [Effects of the Invention]

[0007] According to the present invention, when the vehicle crosses an obstacle, it is possible to prevent it from tipping over backward with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an external perspective view showing an example of the configuration of a traveling device according to the first embodiment. [Figure 2] Figure 2 is a side view showing an example of the configuration of a tracked vehicle. [Figure 3] Figure 3 shows an example of an auxiliary member. [Figure 4] Figure 4 shows the relationship between the height to the center of the road wheels of the running gear and the height of the step. [Figure 5] Figure 5 shows the behavior pattern of the running gear. [Figure 6] Figure 6 shows the behavior of the running gear when it overcomes a step of height h. [Figure 7] Figure 7 is a perspective view showing the configuration of the traveling device according to the second embodiment. [Figure 8] Figure 8 is a magnified view showing the area around the auxiliary member of the traveling device. [Figure 9]Figure 9 is a perspective view showing a modified configuration of the running gear. [Figure 10] Figure 10 is a side view showing a traveling device according to a third embodiment. [Figure 11] Figure 11 shows the behavior pattern of the running gear. [Figure 12] Figure 12 shows an example of bumper installation. [Figure 13] Figure 13 is a side view showing a traveling device according to the fourth embodiment. [Figure 14] Figure 14 shows the behavior pattern of the running gear. [Modes for carrying out the invention]

[0009] The embodiment of the traveling device will be described in detail below with reference to the attached drawings.

[0010] (First Embodiment) Figure 1 is an external perspective view showing an example of the configuration of the traveling device 1 according to the first embodiment.

[0011] In this specification, the Y direction refers to the width direction of the travel device 1. The X direction refers to the travel direction (direction of movement) of the travel device 1, and the Z direction refers to the height direction of the travel device 1.

[0012] The running gear 1 has tracked running bodies 11a, 11b and a main body 10.

[0013] The tracked vehicles 11a and 11b are units that serve as drive components for the running gear 1. Furthermore, the tracked vehicles 11a and 11b are crawler-type vehicles using metal or rubber belts.

[0014] The crawler traveling bodies 11a and 11b have a larger ground contact area compared to a moving body that travels on tires like an automobile, and can travel stably even in, for example, an environment with poor scaffolding. Also, while a moving body that travels on tires requires a turning space when performing a rotating operation, the traveling device 1 equipped with the crawler traveling bodies 11a and 11b can perform so-called ultra-close ground turning (turning around the center point between the two crawler traveling bodies) and ground contact turning (turning around one of the crawler traveling bodies), so that a rotating operation can be smoothly performed even in a limited space. Note that the traveling device 1 is not limited to being capable of both ultra-close ground turning and ground contact turning, and may be capable of at least either one of ultra-close ground turning and ground contact turning. Note that ultra-close ground turning and ground contact turning are examples of turning operations.

[0015] Here, ultra-close ground turning refers to turning in place around the center of the vehicle body by rotating the left and right crawlers at the same speed in opposite directions. Such a turning method is also called a spin turn or the like. Also, ground contact turning refers to turning around the stationary crawler by stopping one crawler and rotating only the other crawler. Such a turning method is also called a pivot turn or the like.

[0016] The two crawler traveling bodies 11a and 11b are installed on both sides of the main body 10 in a state where the traveling device 1 can travel. Note that the number of crawler traveling bodies is not limited to two, and may be three or more. For example, the traveling device 1 may be installed in a state where it can travel, such as arranging three crawler traveling bodies in parallel in three rows. Also, for example, the traveling device 1 may arrange four crawler traveling bodies in the front, rear, left, and right like the tires of an automobile.

[0017] The crawler running body 11(11a, 11b) has a substantially triangular shape. According to the crawler running body 11 with a substantially triangular shape, for example, when there are restrictions on the front and rear sizes, the ground contact area can be increased within the limited front and rear sizes. Thereby, as described above, the stability during running can be improved. On the other hand, a so-called tank-type crawler that is longer on the upper side (drive wheel side) than on the lower side (idler wheel side) will have a smaller overall ground contact area and become unstable when there are restrictions on the front and rear sizes. Thus, the crawler running body 11 is effective when enhancing the running performance of the relatively small-sized running device 1.

[0018] The main body 10 is a support that supports the crawler running bodies 11a, 11b in a state where they can run, and is also a control device that performs control for driving the running device 1. Further, the main body 10 is equipped with a battery (not shown) that supplies electric power for driving the crawler running bodies 11a, 11b.

[0019] The main body 10 of the running device 1 includes a power button 12, a start button 13, an emergency stop button 14, a status display lamp 15, and an auxiliary member 20.

[0020] The power button 12 is an operation means that a person around the running device 1 presses when turning on or off the power of the running device 1. The start button 13 is an operation means that a person around the running device 1 presses when starting the two crawler running bodies 11a, 11b. The emergency stop button 14 is an operation means that a person around the running device 1 presses when stopping the running device 1 during running.

[0021] The status display lamp 15 is a notification means for notifying the status of the running device 1. The status display lamp 15 lights up, for example, to notify people around of a change in the status of the running device 1 when the status of the running device l changes, such as a decrease in the remaining battery level. Also, the status display lamp 15 lights up, for example, when an object that may interfere with the running of the running device 1 is detected, or when there is a risk of an abnormality.

[0022] Figure 1 shows an example in which the running gear 1 is equipped with one status indicator lamp 15, but the number of status indicator lamps 15 may be two or more. Furthermore, the notification means may be configured to notify the status of the running gear 1 not only of the status indicator lamp 15, but also of the status of the running gear 1 by a warning sound emitted from a speaker, etc.

[0023] Two auxiliary members 20 are provided on the upstream side of the main body 10 of the traveling device 1 in the direction of travel (X direction) (see Figure 3). In this embodiment, two auxiliary members 20 are provided on the upstream side of the main body 10 of the traveling device 1 in the direction of travel (X direction), but this is not the only option, and there may be one or three or more. Details of the auxiliary members 20 will be described later.

[0024] The traveling device 1 is equipped with a distance measuring sensor 152 for horizontal direction detection at a height of 0.5 m, with the direction of travel of the main body 10 facing forward. The distance measuring sensor 152 for horizontal direction detection performs distance measurement in two dimensions, for example, by detection using laser light. The distance measuring sensor 152 is, for example, an LRF (Laser Range Finder) or a 2D-LiDAR (Light Detection And Ranging). Examples of 2D-LiDAR sensors include MEMS (Micro Electro Mechanical Systems) type and rotating mirror type.

[0025] The distance measuring sensor 152 measures the distance to an object and the direction in which the object is located based on the measurement of the time it takes for the laser beam to hit the object and bounce back. The distance measuring sensor 152 can measure a range of 270 degrees centered on the forward X direction. The traveling device 1 uses the distance measuring sensor 152 to measure the distance to a wide range of objects in the horizontal direction and uses this as obstacle information.

[0026] In addition, the traveling device 1 is equipped with a distance measuring sensor 153 for diagonal direction detection, positioned at a height of 0.9 m and a depression angle of 30 degrees, with the traveling direction of the main body 10 facing forward. This installation position is designed to allow detection of the road surface up to the front of the traveling device 1. The distance measuring sensor 153 for diagonal direction detection is, for example, an LRF or 3D-LiDAR capable of measuring distance in three dimensions. Examples of 3D-LiDAR type three-dimensional distance measuring sensors include MEMS type and rotating mirror type.

[0027] The 3D-LiDAR used is a non-repetitive scanning type that can measure a range of 70.4 degrees cone-shaped from the center of the sensor detection surface and can measure distances up to 90m. The non-repetitive scanning method scans by slightly shifting the phase in the horizontal and vertical directions, like drawing a flower, and is characterized by the fact that the point cloud coverage within the measurement range increases with the accumulation of data over time. The distance measuring sensor 153 is mounted at an angle below horizontal so that it is angled downwards with a predetermined inclination angle relative to a horizontal road surface.

[0028] The distance measuring sensor 153 irradiates objects such as road surface obstacles with laser light, and measures the distance to the object and the direction in which the object is located based on the time it takes for the laser light to hit the object and bounce back, and acquires the measured results as data. The optimal installation position of the distance measuring sensor 153 depends on the width and length of the tracks of the tracked vehicles 11a and 11b, as well as the size, width, depth, and height of the object to be detected.

[0029] In addition, the traveling device 1 is equipped with multiple cameras 151, with the direction of travel of the main body 10 facing forward.

[0030] Next, we will explain the configuration of the tracked vehicle 11 (11a, 11b).

[0031] Here, Figure 2 is a side view showing an example of the configuration of the tracked vehicle 11. In this embodiment, the running gear 1 comprises two tracked vehicles 11a and 11b as shown in Figure 1, but in the following description, since their configurations are identical, they will be described as the configuration of the tracked vehicle 11.

[0032] As shown in Figure 2, the tracked vehicle 11 comprises tracks 111, drive wheels 113, in-wheel motors 114, road wheels 115a, 115b, auxiliary mechanism 118, side plates 120, and tensioners 125. Of these, the auxiliary mechanism 118 includes idlers 118a, 118b, and links 119. Although not specifically shown, the tracked vehicle 11 also includes, inside the side plate 120, another side plate that sandwiches the drive wheels 113 etc. together with the side plate 120, and a side plate support that supports the side plate 120 and the other side plate.

[0033] The track 111, also called a crawler, is made of metal or rubber. The track 111 is wrapped around the drive wheel 113 and the road wheels 115a, 115b. The track 111 moves in accordance with the rotation direction of the drive wheel 113, and rotates the tracked vehicle 11 by driving the road wheels 115a, 115b along with it. The track 111 also has a number of protrusions 111a, 111b on its surface. The outer protrusions 111a of the track 111 are provided to allow the vehicle to stably overcome small obstacles such as stones on the road surface. The inner protrusions 111b are provided to prevent the vehicle from coming off the drive wheel 113 or the road wheels 115a, 115b.

[0034] The drive wheels 113 transmit driving force to the tracks 111 to rotate the tracked vehicle 11. The tracked vehicle 11 transmits the driving force (rotational force) transmitted by the in-wheel motor 114 to the drive wheels 113 to the road wheels 115a and 115b via the tracks 111.

[0035] The in-wheel motor 114 is built inside the drive wheel 113 and transmits rotational force to the drive wheel 113. The in-wheel motor 114 rotates around the motor shaft 114a, which is the drive shaft. The rotation axis of the in-wheel motor 114 (motor shaft 114a) becomes the rotation axis (drive shaft) of the drive wheel 113, and the rotational force of the in-wheel motor 114 causes the drive wheel 113 to rotate. The rotational force of the in-wheel motor 114 is then transmitted to the track 111 as driving force. Specifically, the in-wheel motor 114 provides the drive wheel 113 with either positive rotation to advance the running gear 1 or negative rotation to reverse the running gear 1.

[0036] Furthermore, by integrating the in-wheel motor 114 into the drive wheel 113, the structure can be simplified, and by eliminating the use of components such as drive chains or gears, the risk of failures caused by these components can be reduced. In addition, by integrating the in-wheel motor 114 into the drive wheel 113, the driving force can be generated near the outer circumference of the tracked vehicle 11, thereby increasing the torque.

[0037] The road wheels 115a and 115b are rotatably mounted on the tracked chassis 11. The road wheels 115a and 115b rotate around the road wheel axles 116a and 116b as axes of rotation, due to the driving force (rotational force) transmitted from the drive wheels 113 via the tracks 111.

[0038] Here, the drive wheel 113, the road wheel 115a, and the road wheel 115b form a roughly triangular shape in a side view. The track 111 is wrapped around the drive wheel 113, the road wheel 115a, and the road wheel 115b, with the area between the road wheel 115a and the road wheel 115b making contact with the ground. In other words, the drive wheel 113, which houses the in-wheel motor 114, does not make contact with the road surface. As a result, even if the tracked vehicle 11 drives through a puddle, for example, the in-wheel motor 114 will not be submerged in water, and therefore there is no need to provide a special waterproofing mechanism for the in-wheel motor 114.

[0039] Furthermore, as shown in Figure 2, the diameters of the drive wheels 113 and the road wheels 115a and 115b are different. The layout of the mobile unit needs to be designed taking into account factors such as the required size constraints and drivability. Generally, the smaller the diameter of a motor, the lower the torque per unit width tends to be. Therefore, the drive wheels 113, which incorporate the in-wheel motor 114, need to have a diameter greater than or equal to the motor diameter to accommodate the required torque performance. Accordingly, the tracked mobile unit 11 is designed so that the diameter of the drive wheels 113, which are installed above, is larger than the diameters of the road wheels 115a and 115b, in order to satisfy the size constraints of the running gear 1 or the tracked mobile unit 11, as well as the required driving performance. However, if the diameter of the road wheels is also increased while the size of the mobile unit is limited, the contact area with the ground will decrease, impairing driving stability. Therefore, the tracked mobile unit 11 also has the advantage of adopting road wheels 115a and 115b with relatively small diameters, taking into account the diameter of the drive wheels 113.

[0040] The auxiliary mechanism 118 is provided with auxiliary wheels (idlers 118a, 118b) that rotate in conjunction with the track 111, and are oscillating (idlers 118a, 118b) around a pivot axis (link axis 119a). The auxiliary mechanism 118 is also called, for example, an oscillating mechanism, a balance-type auxiliary mechanism, a balance-type oscillating mechanism, a balance-type oscillating wheel, or a balance-type oscillating road wheel. In a side view, the auxiliary mechanism 118 is located at the base of the triangular shape formed by the drive wheel 113 and the road wheels 115a, 115b.

[0041] The auxiliary mechanism 118 includes idlers 118a, 118b, and a link 119. The idlers 118a, 118b are auxiliary wheels positioned between the two road wheels 115a, 115b and rotate in conjunction with the track 111. The idlers 118a, 118b rotate around idler shafts 181a, 181b, respectively. The link 119 is a support that supports the idlers 118a and 118b.

[0042] The side plate 120 is a structural part that supports the drive wheels 113, the road wheels 115a and 115b, and the auxiliary mechanism 118 in the tracked vehicle 11 together with another side plate. The tracked vehicle 11 has a double-support structure that uses two side plates, the side plate 120 and the other side plate, to support the drive wheels 113, the road wheels 115a and 115b, and the auxiliary mechanism 118. The side plate 120 and the other side plate are suspended by a plurality of side plate supports. The side plate 120 and the other side plate support the drive wheels 113 using the motor shaft 114a. The side plate 120 and the other side plate also support the road wheels 115a and 115b, respectively, using the road wheel shafts 116a and 116b. Furthermore, the side plate 120 and the other side plate support the auxiliary mechanism 118 via the link shaft 119a of the link 119 that supports the idlers 118a and 118b.

[0043] The tensioner 125 is made of an elastic material such as a spring and is connected to the motor shaft 114a, which is the rotation axis of the in-wheel motor 114 and the drive wheel 113. The tensioner 125 is installed so that the drive wheel 113 presses against the inside of the track 111, thereby applying tension to the track 111. The tracked vehicle 11 maintains normal transmission of driving force by the track 111 by adjusting the slack of the track 111 with the tensioner 125.

[0044] Here, as shown in Figure 2, the tracked vehicle 11 has a structure that is approximately symmetrical in the front and rear directions of travel, with respect to the drive wheel 113. More specifically, the tracked vehicle 11 is approximately symmetrical in the horizontal direction (Y direction) across the two road wheels 115a and 115b, with respect to the motor shaft 114a of the in-wheel motor 114. In other words, the tracked vehicle 11 has a structure that is approximately symmetrical with respect to the perpendicular to the motor shaft 114a of the in-wheel motor 114.

[0045] For example, a vehicle operating in a confined space needs to frequently perform forward and reverse movements and pivot turns. In this case, if the shape of the tracks or the arrangement of the drive wheels, road wheels, or tensioners is asymmetrical front to back, the driving characteristics may change when moving forward or backward, or the vehicle may not be able to rotate around its center during pivot turns. Therefore, by making the layout (structure) of the tracked vehicle 11 approximately symmetrical front to back, the stability of the vehicle during operation and the simplification of control can be improved. In addition, since the tracked vehicle 11 can be installed without considering the left or right side of the vehicle 1, the number of parts can be reduced.

[0046] Next, we will describe the auxiliary member 20 in detail.

[0047] Here, Figure 3 shows an example of the auxiliary member 20. In Figure 3, the auxiliary member 20 is shown in an enlarged view, and the installation position of the auxiliary member 20 in the traveling device 1 is also shown.

[0048] Conventionally, tracked vehicles may tip over due to uneven terrain such as bumps or undulations, or steps such as stairs, which can make stable travel difficult. Therefore, in this embodiment, the running device 1 is equipped with an auxiliary member 20 attached to the rear (upstream) side in the direction of travel, and the center of gravity of the running device 1 is defined. This allows the running device 1 to prevent tipping backward and travel stably, even when overcoming the maximum possible step height it may have to overcome, with a simple configuration.

[0049] The auxiliary member 20 is a component attached to the main body 10 of the running device 1 to prevent the running device 1 from tipping over and to improve its ability to overcome obstacles on the road surface. As shown in Figure 3, the auxiliary member 20 comprises a base member 21 and a tip contact portion 22.

[0050] The base member 21 serves as the main body of the auxiliary member 20. The base member 21 is formed from a rigid body having sufficient strength (rigidity) to support the weight of the running device 1 during operation. The base member 21 is made of a metal such as stainless steel. The auxiliary member 20 is attached to the main body 10 of the running device 1 via the base member 21.

[0051] The base member 21 has increased strength (rigidity) by bending a long, narrow flat plate into a crank shape. The base member 21 includes a rectangular mounting portion 21a which is the mounting area for the main body 10 of the traveling device 1, and a grounding portion 21b which is integrated with the tip grounding portion 22.

[0052] The auxiliary member 20 is attached to the main body 10 of the running gear 1 such that, in a stationary state, the mounting portion 21a of the base member 21 is approximately parallel to the road surface or the bottom edge of the track 111. The ground contact portion 21b of the base member 21 extends diagonally downward when attached to the main body 10 of the running gear 1 such that, in a stationary state, the mounting portion 21a is approximately parallel to the road surface or the bottom edge of the track 111.

[0053] The auxiliary member 20 has multiple mounting holes 24 in the mounting portion 21a of the base member 21 for attaching the auxiliary member 20. The auxiliary member 20 is fixed and attached to the main body 10 of the traveling device 1 by screw fastening with screws 25 through the mounting holes 24 of the base member 21.

[0054] The tip contact portion 22 is formed at the tip of the contact portion 21b of the base member 21. The tip contact portion 22 is formed in a substantially circular shape so that it makes point contact with the auxiliary member 20 regardless of where it makes contact with the ground. By providing the tip contact portion 22 at the tip of the auxiliary member 20, the traveling device 1 can travel smoothly even when the tip of the auxiliary member 20 makes contact with the ground.

[0055] Here, the diameter of the substantially circular portion of the tip contact area 22 is preferably about twice the size of the expected road surface irregularities, in order to prevent the running device 1 from getting stuck and unable to move due to road surface irregularities during operation. In addition, if the road surface irregularities cannot be determined, the diameter of the substantially circular portion of the tip contact area 22 may be about the same as or slightly smaller than the wheel diameter of the idlers 118a and 118b, for example, to match the size of the tracked running body 11.

[0056] Next, we will explain the relationship between the running gear 1 and the height of the step.

[0057] Figure 4 shows the relationship between the height h0 from the center of the road wheel 115b of the running gear 1 to the height H of the step. Figure 4(a) shows the overall view of the running gear 1, and Figure 4(b) shows a magnified view of the area around the road wheel 115b on the downstream side in the direction of travel of the running gear 1. Figure 5 shows the behavior pattern of the running gear 1.

[0058] As shown in Figure 4, let h0 be the height from the track 111 of the running gear 1, which is horizontally positioned on the lower level of the horizontal ground, to the center of the downstream road wheel 115b in the direction of travel. If there is a step of height H in front of (downstream of) the running gear 1 in the direction of travel, the behavior of the downstream road wheel 115b of the running gear 1 will be divided into three patterns, (A), (B), and (C), as shown in Figure 5, depending on the relationship between the height H of the step and the height h0 to the center of the road wheel 115b. It should be assumed that the driving force of the running gear 1 is sufficient.

[0059] Furthermore, the step height h shown in Figure 5 is the maximum step height that the running gear 1 may be able to overcome, even slightly. In the case of a step of height H (H>h), it is assumed that the running gear 1 cannot overcome that step 100% under any conditions.

[0060] (A) When the step height H is less than or equal to the height h0 to the center of the road wheel 115b As shown in Figure 5(A), the road wheel 115b on the downstream side in the direction of travel of the running gear 1 can overcome a step of height H. For example, the running gear 1 can overcome a step by having the road wheel 115a in contact with the ground via the track 111 and the auxiliary member 20 in contact with the ground, while the outer projection 111a of the track 111 on the road wheel 115b side catches on the top of the step.

[0061] (B) When the step height H is higher than the height h0 to the center of the road wheel 115b, and less than or equal to the height h. As shown in Figure 5(B), the downstream road wheel 115b of the running gear 1 may be able to overcome a step of height H, or it may continue to spin freely in place and be unable to overcome the step of height H. Whether or not the downstream road wheel 115b of the running gear 1 can overcome a step of height H depends on the uneven shape and friction coefficient of the track 111 and the surface of the step, as well as the shape of the step itself.

[0062] (C) When the step height H is greater than the height h As shown in Figure 5(C), the downstream wheel 115b of the running gear 1 in the direction of travel will spin freely in place and will not be able to overcome the step of height H.

[0063] As explained above in the behavior patterns (A), (B), and (C) of the running device 1, in order for the running device 1 to run stably, it is necessary that it be configured to be able to stably overcome even the largest step height h, which is the maximum step height that the running device 1 may be able to overcome, without tipping over.

[0064] Figure 6 shows the behavior of the traveling device 1 when it overcomes a step of height h. When the traveling device 1 overcomes a step of height h in the direction of travel, it behaves as follows.

[0065] As shown in Figure 6(a), when the running gear 1 moves toward a step of height h, the downstream side of the road wheel 115b in the direction of travel first overcomes the step of height h.

[0066] As shown in Figure 6(b), when the traveling device 1 overcomes a step of height h, it begins to tilt backward. As it moves further, the tilt angle of the traveling device 1 increases. As the tilt angle of the traveling device 1 increases, the tip contact portion 22 of the auxiliary member 20 makes contact with the lower step (traveling surface) of the step. The tilt angle of the traveling device 1 continues to increase around the point of contact with the tip contact portion 22 of the auxiliary member 20.

[0067] As shown in Figure 6(c), as the running gear 1 moves further, the upstream wheel 115a in the direction of travel begins to overcome a step of height h. Eventually, the running gear 1 rides up onto the upper step of the step with the wheel 115a. The tilt angle when the wheel 115a is on the upper step (the state shown in Figure 6(c)) is the maximum tilt angle of the running gear 1.

[0068] As shown in Figure 6(c), when the upstream road wheel 115a in the direction of travel is in contact with the upper step of a step of height h via the track 111, and the tip of the auxiliary member 20 that touches the ground is in contact with the lower step, the center of gravity of the running gear 1 is located downstream in the direction of travel with respect to the vertical line extending from the point of contact between the tip of the auxiliary member 20 that touches the ground and the lower step.

[0069] Therefore, according to the running gear 1 of this embodiment, when the road wheel 115a on the upstream side in the direction of travel is in contact with the upper step of a step of height h via the track 111, and the tip of the auxiliary member 20 that touches the ground is in contact with the lower step, the center of gravity of the running gear 1 is configured to be located downstream in the direction of travel with respect to the vertical line extending from the point of contact between the tip of the auxiliary member 20 that touches the ground and the lower step. As a result, even when the running gear 1 overcomes a step of height h, which is the maximum step height that the running gear 1 may overcome, it can prevent tipping backward and travel stably with a simple configuration.

[0070] (Second Embodiment) Next, a second embodiment will be described.

[0071] The second embodiment differs from the first embodiment in that, in the configuration of the auxiliary member, a second contact portion 23 is provided between the tip contact portion 22 and the upstream road wheel 115a in the direction of travel, in addition to the tip contact portion 22 that contacts the horizontal ground at the lower step. In the following description of the second embodiment, the description of parts that are the same as in the first embodiment will be omitted, and the parts that differ from the first embodiment will be described.

[0072] Figure 7 is a perspective view showing the configuration of the traveling device 1 according to the second embodiment. In Figure 7, the auxiliary member 20 is shown in an enlarged view, and the installation position of the auxiliary member 20 in the traveling device 1 is also shown.

[0073] As shown in Figure 7, the auxiliary member 20 is provided with a second ground contact portion 23 located between the tip ground contact portion 22 and the upstream side of the road wheel 115a in the direction of travel, in addition to the tip ground contact portion 22 that contacts the horizontal ground at the lower step of the step. More specifically, the auxiliary member 20 has the second ground contact portion 23 formed on the mounting portion 21a of the base member 21.

[0074] The second grounding portion 23 is provided at the lower part of the rectangular mounting portion 21a. The second grounding portion 23 is formed in a substantially semicircular shape so that it makes point contact regardless of where it makes contact with the ground. The diameter of the substantially semicircular portion of the second grounding portion 23 is, for example, about the same as or slightly smaller than the diameter of the substantially circular portion of the tip grounding portion 22.

[0075] Figure 8 is a magnified view of the area around the auxiliary member 20 of the traveling device 1. Figure 8 shows a magnified view of the lower and upper steps of the step in the same state as shown in Figure 6(c).

[0076] As shown in Figure 8, when the upstream road wheel 115a in the direction of travel is in contact with the horizontal plane of the upper step via the track 111, and the second contact point 23 is also in contact with the same horizontal plane, the center of gravity of the running gear 1 is located downstream in the direction of travel with respect to the vertical line from the point of contact between the second contact point 23 and the horizontal plane of the upper step.

[0077] With this configuration, even if the tip of the auxiliary member 20's contact point 22 of the travel device 1 separates from the horizontal ground of the lower step, the moment direction around the contact point between the upper step's horizontal ground and the second contact point 23 acts in the direction of restoring the device. Therefore, the travel device 1 will not tip over backward but will return to its forward position, becoming horizontal and able to travel stably.

[0078] (modified version) Figure 9 is a perspective view showing a modified configuration of the traveling device 1. In Figure 9, the auxiliary member 20 is shown in an enlarged view, and the installation position of the auxiliary member 20 in the traveling device 1 is also indicated.

[0079] As shown in Figure 9, the auxiliary member 20 may have its tip contact portion 22 formed by a rotatable first wheel 31 and its second contact portion 23 formed by a rotatable second wheel 32. The first wheel 31 and the second wheel 32 are small wheels attached to the base member 21 that rotate freely when the auxiliary member 20 makes contact with the ground.

[0080] The running gear 1 can run smoothly even when the auxiliary member 20 is in contact with the ground, by providing the first wheel 31 and the second wheel 32 on the auxiliary member 20. Furthermore, by providing the first wheel 31 and the second wheel 32 on the auxiliary member 20, the running gear 1 can prevent the auxiliary member 20 from damaging the road surface.

[0081] Here, the diameters of the first wheel 31 and the second wheel 32 are preferably about twice the size of the expected road surface irregularities in order to prevent the wheels from getting stuck and becoming immobile due to road surface irregularities during operation. In addition, if the road surface irregularities cannot be determined, the diameters of the first wheel 31 and the second wheel 32 may be about the same as or slightly smaller than the diameters of the idlers 118a and 118b, for example, to match the size of the tracked vehicle 11.

[0082] By configuring it as described above, the wheels that make contact with the steps between the upper and lower levels become freely rotatable, so the running device 1 has less snagging and resistance against the road surface, and its stability during running can be further improved.

[0083] The wheel replacement described above may be performed on both the tip contact portion 22 and the second contact portion 23 of the auxiliary member 20, or on either one.

[0084] (Third embodiment) Next, a third embodiment will be described.

[0085] The third embodiment differs from the first and second embodiments in that it is equipped with a bumper 16 at a height h above the horizontal ground at the downstream end of the traveling device 1 in the direction of travel. In the following description of the third embodiment, the description of parts that are the same as those of the first and second embodiments will be omitted, and the parts that differ from the first and second embodiments will be described.

[0086] Figure 10 is a side view showing the traveling device 1 according to the third embodiment. Figure 11 is a diagram showing the behavior pattern of the traveling device 1.

[0087] As shown in Figure 10, the traveling device 1 according to the third embodiment is equipped with a bumper 16, which is an impact-absorbing member that absorbs and mitigates impacts, at the downstream end of the traveling device 1 in the direction of travel, at a height h from the horizontal ground, when the traveling device 1 is positioned horizontally on the horizontal ground which is the lower step. The height h is, as described above, the maximum step height that the traveling device 1 may have to overcome, even slightly.

[0088] Even when the bumper 16 is provided as shown in Figure 10, similar to Figure 1, if there is a step of height H in front of (downstream of) the running gear 1 in the direction of travel, the behavior of the road wheel 115b on the downstream side in the direction of travel of the running gear 1 will be divided into three patterns, (A), (B), and (C), as shown in Figure 11, depending on the relationship between the height H of the step and the height h0 to the center of the road wheel 115b. Note that the driving force of the running gear 1 is sufficient, and h0 is defined as the height to the center of the road wheel 115b on the downstream side in the direction of travel via the track 111 of the running gear 1, which is horizontally arranged on a horizontal ground.

[0089] Furthermore, the height h of the step is the maximum step height that the running device 1 has even a slight chance of overcoming. In the case of a step of height H (H>h), it is assumed that the running device 1 cannot overcome that step 100% of the time, under any circumstances.

[0090] (A) When the step height H is less than or equal to the height h0 to the center of the road wheel 115b As shown in Figure 11(A), the road wheel 115b on the downstream side in the direction of travel of the running gear 1 can overcome a step of height H. For example, the running gear 1 can overcome a step by having the road wheel 115a in contact with the ground via the track 111 and the auxiliary member 20 in contact with the ground, while the outer projection 111a of the track 111 on the road wheel 115b side catches on the top of the step.

[0091] (B) When the step height H is higher than the height h0 to the center of the road wheel 115b, and less than or equal to the height h. As shown in Figure 11(B), the downstream wheel 115b of the running gear 1 may be able to overcome a step of height H, or it may continue to spin in place and be unable to overcome it.

[0092] (C) When the step height H is greater than the height h As shown in Figure 11(C), the bumper 16 of the running gear 1 hits the step, and it cannot overcome the step of height H.

[0093] As described above, the behavior of the running gear 1 is almost the same as the pattern shown in Figure 5. However, the height H of a step that is higher than the height h that cannot be reliably overcome is a variable value in the state of Figure 1, which varies depending on the uneven shape of the track 111 and the surface of the step, the coefficient of friction, and the shape of the step itself. In contrast, by providing the bumper 16 as shown in Figure 10, it becomes a fixed and quantitative value. Therefore, the positional configuration of the auxiliary member 20 can be quantitatively designed so that the running gear 1 can overcome a step of height h without tipping over.

[0094] Here, Figure 12 shows an example of how the bumper 16 is installed. For example, as shown in Figure 12, when designing the position configuration of the auxiliary member 20, first, when the running device 1 is tilted onto a step of height h, it is confirmed that the center of gravity is downstream in the direction of travel from the vertical line of the first wheel 31 and the second wheel 32, and the bumper 16 is installed at the height h position.

[0095] The vehicle 1 may also be equipped with an impact detection sensor (not shown) inside the bumper 16, which is an impact detection device that detects when something collides with the bumper 16. The impact detection sensor detects acceleration (impact, vibration) applied from the outside and generates an electrical signal. For example, an acceleration sensor mainly composed of piezoelectric ceramic can be used as the impact detection sensor. As shown in Figure 9(C), when the bumper 16 of the vehicle 1 hits a step, the impact detection sensor emits a signal that something has hit the bumper 16. The vehicle 1 can also be controlled by triggering the signal that something has hit to stop its drive and notify a remote operator, or it can choose a route to avoid the step and continue driving.

[0096] (Fourth embodiment) Next, a fourth embodiment will be described.

[0097] The fourth embodiment differs from the third embodiment in that it is provided with a guide member 30 on the lower side of the bumper 16 of the running gear 1. In the following description of the fourth embodiment, the description of parts that are the same as those of the third embodiment will be omitted, and the parts that differ from the third embodiment will be described.

[0098] Figure 13 is a side view showing the running gear 1 according to the fourth embodiment. Figure 13(a) shows an overall view of the running gear 1, and Figure 13(b) shows a magnified view of the area around the road wheel 115b on the downstream side in the direction of travel of the running gear 1. Figure 14 is a diagram showing the behavior pattern of the running gear 1.

[0099] As shown in Figure 13, the running gear 1 according to the fourth embodiment is equipped with a guide member 30 on the lower side of the bumper 16. As shown in Figure 13, in the running gear 1 arranged in a horizontal position, the guide member 30 is inclined from the tip of the bumper 16 toward the track 111. More specifically, the guide member 30 has an oblique shape that extends downward from the height h0 of the center of the downstream road wheel 115b in the direction of travel.

[0100] As shown in Figure 13, by providing a guide member 30 on the lower side of the bumper 16, when there is a step of height H in front of (downstream of) the running gear 1 in the direction of travel, the behavior of the road wheel 115b on the downstream side in the direction of travel of the running gear 1 is divided into two patterns, (A) and (B), as shown in Figure 14, depending on the relationship between the height H of the step and the height h0 to the center of the road wheel 115b.

[0101] (A) When the step height H is less than or equal to the height h0 to the center of the road wheel 115b As shown in Figure 14(A), when the running gear 1 is horizontal, the downstream wheel 115b in the direction of travel of the running gear 1 is guided to the corner of the upper step of a step of height H. More specifically, due to the action of the guide member 30, the downstream wheel 115b in the direction of travel of the running gear 1 is guided to a position of the track 111 that is less than or equal to the height h0 of the center of the wheel 115b, and is able to overcome a step of height H.

[0102] As a result, when the downstream wheel 115b of the running gear 1 overcomes a step of height H, the running gear 1 can stably overcome the step and travel without tipping over.

[0103] If the running gear 1 is not equipped with a guide member 30, there will be cases where the vehicle can overcome the step and cases where it cannot, depending on the uneven shape of the track 111 and the surface of the step, the coefficient of friction, and the shape of the step itself. However, if the running gear 1 is equipped with a guide member 30, the running gear 1 can reliably overcome the step when the step height is h or less, and can continue to run stably without tipping over afterward.

[0104] Therefore, the specification value for the running gear 1 allows for specifying the step height h that it can handle.

[0105] (B) When the step height H is higher than the height h0 to the center of the road wheel 115b As shown in Figure 14(B), if the step height H is higher than the height h0 to the center of the road wheel 115b, the bumper 16 of the running gear 1 will hit the step, and the running gear 1 will not be able to overcome the step of height H.

[0106] In this case, the vehicle 1 can either stop its drive and notify a remote operator based on a signal from an impact detection sensor that detects a collision, or it can choose a route to avoid the obstacle and continue driving.

[0107] Thus, according to this embodiment, the guide member 30 ensures that the vehicle can reliably overcome steps of h height or less without tipping over. Furthermore, if the step is higher than h height, the vehicle will collide with the bumper 16, and the vehicle can start a pre-programmed movement based on the signal from the impact detection sensor.

[0108] Examples of the present invention are as follows: <1> A tracked vehicle comprises a track, a drive wheel that provides driving force to the track, and at least two road wheels positioned below the drive wheel, and moves by rotating the track that is wrapped around the drive wheel and the road wheels. An auxiliary member provided on the upstream side of the direction of travel of the aforementioned tracked vehicle, which assists in preventing tipping over, A running device equipped with, When the road wheels located downstream in the direction of travel of the tracked vehicle are in contact with the upper step of a predetermined step of a specific height relative to the running surface via the tracks, and the end of the auxiliary member is in contact with the running surface, the center of gravity of the running device is located downstream in the direction of travel of the tracked vehicle with respect to the vertical line from the point of contact between the end of the auxiliary member and the running surface. A traveling device characterized by the following features. <2> The aforementioned auxiliary member is A rigid base member is provided on the aforementioned tracked vehicle, The tip portion of the base member is provided and contacts the running surface, Features that <1> The running gear described above. <3> The aforementioned auxiliary member is The tracked vehicle is provided with a second contact portion located between the aforementioned front contact portion and the road wheel located on the upstream side in the direction of travel of the tracked vehicle, The second contact point is located downstream of the tracked vehicle in the direction of travel, with respect to the vertical line from the point of contact between the second contact point and the upper step, when the road wheel located upstream of the tracked vehicle is in contact with the upper step via the track, and the second contact point is in contact with the upper step, Characterized by <2> The running gear described above. <4> The auxiliary member is configured such that at least one of the front contact portion and the second contact portion is a rotatable wheel. Characterized by <3> The running gear described above. <5> The front end of the tracked vehicle on the downstream side in the direction of travel, at a predetermined height from the travel surface, is provided with an impact-absorbing member that absorbs impact. Characterized by <1> or <4> A running device as described in any one of the following. <6> The impact absorbing member is equipped with an impact detection device that emits a signal when it detects that something has collided with the impact absorbing member. Characterized by <5> The running gear described above. <7> A guide member is provided on the lower side of the shock-absorbing member, which is inclined from the tip of the shock-absorbing member toward the road wheel located downstream in the direction of travel of the tracked vehicle. Characterized by <5> or <6> The running gear described above. <8> The aforementioned predetermined height is the maximum height of a step that the tracked vehicle can overcome. Characterized by <1> or <7> A running device as described in any one of the following. [Explanation of Symbols]

[0109] 1. Traveling device 11,11a,11b Tracked vehicle 16. Impact absorbing member 20 Auxiliary members 21 Base member 22 Tip grounding part 23 Second grounding section 30 Guide member 31,32 wheels 111 Tracks 113 Drive wheels 115a, 115b road wheels [Prior art documents] [Patent Documents]

[0110] [Patent Document 1] Japanese Patent Publication No. 2012-061963

Claims

1. A tracked vehicle comprises a track, a drive wheel that provides driving force to the track, and at least two road wheels positioned below the drive wheel, and moves by rotating the track that is wrapped around the drive wheel and the road wheels. An auxiliary member provided on the upstream side of the direction of travel of the aforementioned tracked vehicle, which assists in preventing tipping over, A running device equipped with, When the road wheels located downstream in the direction of travel of the tracked vehicle are in contact with the upper step of a predetermined step of a specific height relative to the running surface via the tracks, and the end of the auxiliary member is in contact with the running surface, the center of gravity of the running device is located downstream in the direction of travel of the tracked vehicle with respect to the vertical line from the point of contact between the end of the auxiliary member and the running surface. A traveling device characterized by the following features.

2. The aforementioned auxiliary member is A rigid base member is provided on the aforementioned tracked vehicle, The tip portion of the base member is provided and contacts the running surface, The traveling device according to claim 1, characterized by comprising:

3. The aforementioned auxiliary member is The tracked vehicle is provided with a second contact portion located between the aforementioned front contact portion and the road wheel located on the upstream side in the direction of travel of the tracked vehicle, The second contact point is located downstream of the tracked vehicle in the direction of travel, with respect to the vertical line from the point of contact between the second contact point and the upper step, when the road wheel located upstream of the tracked vehicle is in contact with the upper step via the track, and the second contact point is in contact with the upper step, The traveling device according to feature 2.

4. The auxiliary member is configured such that at least one of the front contact portion and the second contact portion is a rotatable wheel. The traveling device according to feature 3.

5. The front end of the tracked vehicle on the downstream side in the direction of travel, at a predetermined height from the travel surface, is provided with an impact-absorbing member that absorbs impact. The traveling device according to any one of claims 1 to 4.

6. The impact absorbing member is equipped with an impact detection device that emits a signal when it detects that something has collided with the impact absorbing member. The traveling device according to feature 5.

7. A guide member is provided on the lower side of the shock-absorbing member, which is inclined from the tip of the shock-absorbing member toward the road wheel located downstream in the direction of travel of the tracked vehicle. The traveling device according to feature 5.

8. The aforementioned predetermined height is the maximum height of a step that the tracked vehicle can overcome. The traveling device according to feature 1.

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