Rocker bogie

Abstract

To foot on steps varying in height without providing a rocker bogie mechanism with a length adjusting mechanism for a leg part.SOLUTION: A rocker bogie car comprises: a bogie link which is provided with front wheels, middle wheels and rear wheels in pairs to the right and left respectively, the front wheels and middle wheels being pivoted respectively; a rocker link on which the rear wheels are pivoted; a main body which is fixed to the rocker link; and a sensor which detects steps in an ongoing direction and also measures distances to the steps. The bogie link is pivoted on the main body or rocker link and can rotate freely or dynamically, the front wheels and rear wheels each have, on an outer periphery of a main wheel, a plurality of free wheels supported rotatably at an angle 45° to an axle and arrayed in a circumferential direction, the middle wheels each have, on an outer periphery of a main wheel, a plurality of free wheels supported rotatably in a direction of 90° to an axle and arrayed in a circumferential direction, and once the sensor detects a step in the ongoing direction, the front wheels are lifted to higher than the height of the step.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rocker bogie vehicle. [Background technology]

[0002] Generally, it is difficult for wheeled transport devices to travel on rough terrain, and therefore technological developments are underway to enable such transport devices to travel on rough terrain. An example of such technology is the rocker bogie mechanism. Furthermore, mobile devices that run on wheels are required to have not only technology that allows them to travel on uneven ground, but also the ability to overcome steps.

[0003] Patent Document 1, which is a conventional technology, discloses a moving body that can handle steps of various heights, which includes an acquisition unit that moves over steps located ahead in the direction of movement and acquires step information related to the steps, a rocker bogie mechanism having a pair of three wheels lined up along the direction of movement, and which is capable of adjusting the spacing between the three wheels in the direction of movement and the lengths of the three legs to which the three wheels are connected, and a calculation unit that calculates the spacing between the three wheels and the lengths of the two front legs of the three legs necessary to overcome the step based on the acquired step information, and outputs the calculation result. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-66393 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional technology, the rocker bogie mechanism requires a mechanism for adjusting the length of the legs.

[0006] The present invention has been made in consideration of the above, and provides a technology that can traverse steps of various heights without providing a leg length adjustment mechanism in the rocker bogie mechanism. [Means for solving the problem]

[0007] One aspect of the present invention that solves the above-mentioned problems and achieves the object is a rocker bogie car with a total of six wheels, with a pair of front wheels, middle wheels, and rear wheels provided on the left and right sides, and includes bogie links on which the front wheels and middle wheels are each journaled, rocker links on which the rear wheels are journaled, a main body fixed to the rocker link, and a sensor that detects steps in the direction of travel and measures the distance to the steps. The bogie link is journaled on the main body or the rocker link and can rotate freely or dynamically. The front wheels and the rear wheels are rotatably supported on the outer periphery of the main wheels at an angle of 45° to the axle and have a structure having a plurality of freewheels lined up in the circumferential direction, and the middle wheels are rotatably supported on the outer periphery of the main wheels at an angle of 90° to the axle and have a structure having a plurality of freewheels lined up in the circumferential direction. When the sensor detects a step in the direction of travel, the rocker bogie car lifts the front wheels above the height of the step.

[0008] In one aspect of the present invention, the rocker bogie vehicle detects the step as a discontinuous point in the distance measurement of the sensor, calculates the height of the step, and calculates the height to lift the front wheels based on the calculated step height.

[0009] A rocker bogie vehicle according to one aspect of the present invention calculates the distance to the step in the direction of travel and calculates the height to which the front wheels are lifted based on the calculated distance and the step height.

[0010] In one embodiment of the rocker bogie vehicle of the present invention, the step is an uphill step, and the front wheels are raised above the step height and moved forward, then grounded on the step, the middle wheels are raised above the height of the front wheels, and the rear wheels are rotated along the rise vertical surface of the step to traverse the step.

[0011] In one embodiment of the rocker bogie vehicle of the present invention, the step is an uphill step, and the front wheels are raised above the step height and moved forward, then grounded on the step, the middle wheels are rotated along the rise vertical surface of the step, and the rear wheels are rotated along the rise vertical surface of the step to traverse the step.

[0012] In one aspect of the present invention, the rocker bogie vehicle has a step that is a downward step, and the front wheels, the middle wheels, and the rear wheels are rotated sequentially along the rise vertical surface of the step to traverse the step.

[0013] In one aspect of the rocker bogie vehicle of the present invention, the step is a downward step, and the front wheels are rotated along the riser vertical surface of the step to ground the bottom of the step, and the bogie link angle is fixed. After the front wheels and rear wheels move forward, the middle wheels are grounded under the step, and the rear wheels are rotated along the riser vertical surface of the step to traverse the step.

[0014] In one aspect of the present invention, when the rocker bogie vehicle is not directly facing the step, the rotation of the front wheels, the middle wheels, and the rear wheels is controlled so that the vehicle faces the step. The vehicle traverses the step while facing the step.

[0015] In one aspect of the present invention, when the rocker bogie vehicle is not directly facing the step, it traverses the step by independently controlling the front wheels, the middle wheels, and the rear wheels on the left and right. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a rocker bogie vehicle that can traverse steps of various heights without providing a leg length adjustment mechanism in the rocker bogie mechanism. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a top view showing the configuration of a rocker bogie vehicle according to the first embodiment. [Figure 2] FIG. 2 is a schematic side view showing an example of the configuration of the center of gravity and wheels of the rocker bogie vehicle according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing an example of data acquisition by a 3D camera. [Figure 4] FIG. 4 is a functional block diagram showing the rocker bogie vehicle travel control unit in the first embodiment. [Figure 5] FIG. 5 is a flowchart showing the autonomous driving operation of the rocker bogie vehicle according to the first embodiment. [Figure 6] FIG. 6(A) is a diagram illustrating a method for detecting an upward step of a rocker bogie vehicle according to this embodiment, and FIG. 6(B) is a diagram illustrating a method for detecting a downward step of a rocker bogie vehicle according to this embodiment. [Figure 7] FIG. 7A is a diagram for explaining the continuity of distance data for detecting a step (edge), and FIG. 7B is a diagram showing the geometric relationship of FIG. 7A. [Figure 8] Figure 8(A) is a diagram showing parameters when detecting an upward step of a rocker bogie vehicle according to embodiment 2, and Figure 8(B) is a diagram showing parameters when detecting a downward step of a rocker bogie vehicle according to embodiment 2. [Figure 9] FIG. 9 is a diagram showing parameters of the rocker bogie vehicle according to the third embodiment. [Figure 10] FIG. 10 is a diagram showing a state in which the front wheels of the rocker bogie vehicle according to the third embodiment are lifted. [Figure 11] FIG. 11 is a diagram for explaining the positional relationship in a state in which the front wheels of the rocker bogie vehicle according to the third embodiment are lifted. [Figure 12] Figure 12(A) is a diagram showing the displacement of the front wheels of a rocker bogie vehicle according to embodiment 3 when the front wheels are lifted, and Figure 12(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in Figure 12(A). [Figure 13]Figure 13(A) is a diagram showing the displacement of the middle wheel when the front wheel of the rocker bogie vehicle according to embodiment 3 is lifted, and Figure 13(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in Figure 13(A). [Figure 14] FIG. 14(A) is a diagram for explaining the calculation of the angle α, and FIG. 14(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 14(A). [Figure 15] FIG. 15(A) is a diagram for explaining the calculation of the length q, and FIG. 15(B) is a diagram showing the geometric relationship in which the parameters shown in FIG. 15(A) are extracted. [Figure 16] FIG. 16(A) is a diagram for explaining the calculation of the length r, and FIG. 16(B) is a diagram showing the geometric relationship in which the parameters shown in FIG. 16(A) are extracted when r2>r3. [Figure 17] FIG. 17 is a diagram supplementing the geometric relationship in FIG. 16(B). [Figure 18] FIG. 18(A) is a diagram for explaining the calculation of the length t and the length u, and FIG. 18(B) is a diagram showing the geometric relationship in which the parameters shown in FIG. 18(A) are extracted. [Figure 19] FIG. 19 is a diagram showing a state in which the rocker-bogie vehicle according to the fourth embodiment detects an upward step in front of it and lifts the front wheels at a drive angle ω. [Figure 20] FIG. 20 is a diagram showing the rocker bogie vehicle according to the fourth embodiment in a state where the vehicle has moved forward from FIG. 19 so that the front wheels are above the step. [Figure 21] FIG. 21 is a diagram showing the rocker bogie vehicle according to the fourth embodiment in a state where the front wheels come into contact with a step as shown in FIG. [Figure 22] FIG. 22 is a diagram showing a state in which the angle of the bogie link is controlled to lift the center wheel from FIG. [Figure 23] FIG. 23 is a diagram showing the rocker bogie vehicle according to the fourth embodiment in a state where the center wheels have gone over the step from FIG. 22 and have moved forward. [Figure 24]FIG. 24 is a diagram showing the rocker bogie vehicle according to the fourth embodiment in a state where the rear wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 25] FIG. 25 is a diagram showing the rocker bogie vehicle according to the fourth embodiment in a state where the vehicle has moved further forward from the state shown in FIG. 24 and the rear wheels have climbed over a step. [Figure 26] FIG. 26 is a diagram showing the rocker bogie vehicle according to the fifth embodiment in a state where the front wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 27] FIG. 27 is a diagram showing the rocker bogie vehicle according to the fifth embodiment in a state in which the center wheels are in contact with the vertical riser surfaces (riser boards) and are lifted up from the state shown in FIG. [Figure 28] FIG. 28 is a diagram showing the rocker bogie vehicle according to the fifth embodiment in a state further forward from that shown in FIG. [Figure 29] FIG. 29 is a diagram showing the rocker-bogie vehicle according to the sixth embodiment when detecting a downward step. [Figure 30] FIG. 30 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state further forward from that shown in FIG. [Figure 31] FIG. 31 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state where the front wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 32] FIG. 32 is a diagram showing a rocker bogie vehicle according to the sixth embodiment in a state where the front wheels are further lowered from the state shown in FIG. [Figure 33] FIG. 33 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state further forward from that shown in FIG. [Figure 34] FIG. 34 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state where the center wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 35] FIG. 35 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state further forward from that shown in FIG. [Figure 36] FIG. 36 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state where the rear wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 37]FIG. 37 is a diagram showing the rocker bogie vehicle according to the sixth embodiment in a state further forward from that shown in FIG. [Figure 38] FIG. 38 is a diagram showing the rocker bogie vehicle according to the seventh embodiment in a state where the front wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 39] FIG. 39 is a diagram showing the rocker bogie vehicle according to the seventh embodiment in a state where the front wheels have further descended from FIG. 38 and reached the lower stage. [Figure 40] FIG. 40 is a diagram showing the rocker bogie vehicle according to the seventh embodiment in a state further forward from that shown in FIG. [Figure 41] FIG. 41 is a diagram showing a rocker bogie vehicle according to the seventh embodiment in a state where the angle of the bogie link is reduced from that of FIG. [Figure 42] FIG. 42 is a diagram showing the rocker bogie vehicle according to the seventh embodiment in a state where the rear wheels are in contact with the vertical riser surface after moving further forward from the state shown in FIG. [Figure 43] FIG. 43 is a diagram showing the top surface of a rocker bogie vehicle facing a step in front of the vehicle according to the eighth embodiment. [Figure 44] FIG. 44 is a diagram showing the top view of the rocker bogie vehicle shown in FIG. 43 when it has been turned so as to face the step. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. However, the present invention should not be construed as being limited by the following embodiments.

[0019] <Embodiment 1> FIG. 1 is a top view showing the configuration of a rocker bogie vehicle 10 according to this embodiment. The rocker bogie vehicle 10 shown in FIG. 1 has a symmetrical link structure and constitutes a six-wheeled rocker bogie vehicle body. The right front wheel 1aR and the right center wheel 1bR are journaled to the right bogie link 2R, and the left front wheel 1aL and the left center wheel 1bL are journaled to the left bogie link 2L. The right rear wheel 1cR is journalled on a right rocker link 3R, and the left rear wheel 1cL is journalled on a left rocker link 3L. The right bogie link 2R and the right rocker link 3R are journaled in support holes, and the left bogie link 2L and the left rocker link 3L are journaled in support holes. These supports are mechanisms that can actively control the rotation angle, and are called bogie link angle suspensions. The right rocker link 3R and the left rocker link 3L are fixed to the main body 5. The right bogie link 2R and the left bogie link 2L may be pivotally supported on the main body 5. The right bogie link 2R and the left bogie link 2L can rotate freely (in a free junction state where no torque is applied) or dynamically. The rocker bogie car 10 shown in FIG. 1 has a right bogie link control motor 17R as a mechanism for controlling the angle between the right bogie link 2R and the right rocker link 3R, and a left bogie link control motor 17L as a mechanism for controlling the angle between the left bogie link 2L and the left rocker link 3L. The right bogie link control motor 17R and the left bogie link control motor 17L enable angle control at the axle support, or can create free rotation (a free junction state where no torque is applied). Such a configuration can be realized by an actuator that can freely control the rotational driving force, such as a torque motor or a Harmonic Drive (registered trademark).

[0020] When the rocker bogie vehicle 10 shown in FIG. 1 detects a step in the direction of travel while traveling using a 3D camera 18, which is a sensor that detects steps in the direction of travel and measures the distance to the step, the right bogie link 2R and the left bogie link 2L operate to swing up the right front wheel 1aR and the left front wheel 1aL, respectively, and lift the right front wheel 1aR and the left front wheel 1aL higher than the step to traverse the step.

[0021] The front right wheel 1aR, front left wheel 1aL, rear right wheel 1cR and rear left wheel 1cL are Mecanum wheels (registered trademark), and the middle right wheel 1bR and middle left wheel 1bL are Omni wheels (registered trademark). The six wheels, front right wheel 1aR, front left wheel 1aL, center right wheel 1bR, center left wheel 1bL, rear right wheel 1cR and rear left wheel 1cL, can be independently driven and controlled. By controlling the rotation of these six wheels as forward or reverse, the rocker bogie vehicle 10 can travel forward, backward, sideways, diagonally, or spin turns. In the following explanation, the right front wheel 1aR and the left front wheel 1aL may be referred to as the front wheels 1a, the right middle wheel 1bR and the left middle wheel 1bL may be referred to as the middle wheels 1b, the right rear wheel 1cR and the left rear wheel 1cL may be referred to as the rear wheels 1c, the right bogie link 2R and the left bogie link 2L may be referred to as the bogie link 2, the right rocker link 3R and the left rocker link 3L may be referred to as the rocker link 3, and the right bogie link control motor 17R and the left bogie link control motor 17L may be referred to as the bogie link control motor 17.

[0022] FIG. 2 is a schematic side view showing an example of the configuration of the center of gravity and wheels of the rocker bogie vehicle 10 according to this embodiment. The weight mg of the body of the rocker bogie car 10, the force N1 supported by the front wheel 1a on the ground, the force N2 supported by the middle wheel 1b on the ground, and the force N3 supported by the rear wheel 1c on the ground are N1 = N2 = N3, and mg = N1 + N2 + N3, and the rocker bogie car 10 is configured to be balanced. If the distance between the front wheel 1a and the axle support is A1, the distance between the middle wheel 1b and the axle support is A2, the distance between the position of the center of gravity of the rocker bogie car 10 and the position of the axle support of the bogie link 2 is B1, and the distance between the position of the center of gravity of the rocker bogie car 10 and the position of the rear wheel 1c of the rocker link 3 is B2, then from moment balance, A2 × N2 = A1 × N1, B2 × N3 = B1 × (N1 + N2), and therefore A1 = A2, B2 = 2 × B1.

[0023] The right front wheel 1aR, left front wheel 1aL, right rear wheel 1cR, and left rear wheel 1cL shown in FIG. 1 are Mecanum wheels (registered trademark), and each main wheel has multiple free wheels rotatably supported at an angle of 45° to the axle and arranged in the circumferential direction on its outer periphery. The diagonal lines in the right front wheel 1aR, the left front wheel 1aL, the right rear wheel 1cR, and the left rear wheel 1cL shown in FIG. 1 indicate the direction of the rotation axis of the freewheel.

[0024] The main wheel of the right front wheel 1aR is connected to and driven by a motor 14R, the main wheel of the left front wheel 1aL is connected to and driven by a motor 14L, the main wheel of the right rear wheel 1cR is connected to and driven by a motor 16R, and the main wheel of the left rear wheel 1cL is connected to and driven by a motor 16L. The motors 14R, 14L, 16R, and 16L are independent of each other, and the main wheels of the front right wheel 1aR, the front left wheel 1aL, the rear right wheel 1cR, and the rear left wheel 1cL can be controlled independently of each other.

[0025] The right middle wheel 1bR and left middle wheel 1bL shown in Figure 1 are Omniwheels (registered trademark), and each main wheel has multiple freewheels rotatably supported at 90° to the axle on its outer periphery and arranged in the circumferential direction. The horizontal lines in the right middle wheel 1bR and the left middle wheel 1bL shown in FIG. 1 indicate the direction of the rotation axis of the freewheel.

[0026] The main wheel of the middle right wheel 1bR is connected to and driven by a motor 15R, and the main wheel of the middle left wheel 1bL is connected to and driven by a motor 15L. The motors 15R and 15L are independent of each other, and the main wheel of the middle right wheel 1bR and the main wheel of the middle left wheel 1bL can be controlled independently of each other. In the following description, the motors 14R and 14L may be referred to as motors 14, the motors 15R and 15L may be referred to as motors 15, and the motors 16R and 16L may be referred to as motors 16.

[0027] As described above, the rocker bogie vehicle 10 can move freely forward, backward, left and right by combining six wheels: right front wheel 1aR, left front wheel 1aL, right center wheel 1bR, left center wheel 1bL, right rear wheel 1cR and left rear wheel 1cL.

[0028] The rocker bogie vehicle 10 shown in FIGS. The 3D camera 18 is a depth sensor that acquires distance information using ToF (Time of Flight) and detects an upward step ahead. However, the sensor for detecting the uphill step ahead is not limited to this as long as it can measure the distance to obstacles including steps ahead, and instead of the 3D camera 18, an ultrasonic sensor, an infrared sensor, a radar, or a 3DLIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging), etc. may be used.

[0029] The 3D camera 18 has a CCD (Charge Coupled Device) camera and acquires two-dimensional images and depth data using near-infrared rays (IR). Instead of near-infrared rays IR, ultrasonic waves or radar may be used. The output data of the 3D camera 18 is, for example, two-dimensional coordinate data of pixels having a resolution equivalent to VGA (640×480) when the image is captured. When the output data of the 3D camera 18 is video information, it can be RGB data or YUV data, but YUV data is preferable from the viewpoint of data compression. RGB data represents color information by combining the three primary colors of light: red, green, and blue. Furthermore, YUV data represents color information by combining a luminance signal (Y), the difference between the luminance signal and a blue signal (U), and the difference between the luminance signal and a red signal (V). For example, a format such as YUV422 is defined based on the resolution of the output data from the 3D camera 18, and these areas are represented by two-dimensional coordinates (x, y).

[0030] FIG. 3 is a diagram showing an example of data acquisition by the 3D camera 18. For example, when expressed in two-dimensional coordinates, the image area is (0,0) to (x,y) to (640,480), and is expressed as (x,y,z) including the distance data z (Depth) to each (x,y) coordinate. This is the three-dimensional coordinate system (0,0,z 0_0 )~(x,y,z x_y )~(640,480,z 640_480 ) may also be expressed as Alternatively, other formats may be used to combine depth information with near-infrared IR image information. In this case, depth information is obtained by ToF together with, for example, 640x480 IR image information. As an example of an array, the YUV422 area is (0,0) to (640,480), and the distance data z (Depth) is (z 0_0 )~(z x_y )~(z 640_480 ), and the distance data z (Depth) may be combined with a planar two-dimensional coordinate.

[0031] The joint between the bogie link 2 and the rocker link 3 has a drive shaft 19, which is connected to a bogie link control motor 17, which is a drive actuator that can freely change the bogie link angle. The rocker bogie vehicle 10 is capable of controlling the rotation speed of the drive shaft 19 and the drive angle of the bogie link 2. The bogie link 2 may be driven by the bogie link control motor 17 in accordance with a command for the drive angle, or may be in a free junction state. When the driving force of the bogie link control motor 17 is set to 0, the bogie link 2 is in a free junction state.

[0032] The rocker bogie car 10 is provided with an angle sensor. The angle sensor may be a mechanical (contact) type that is attached to the drive shaft 19 and detects the rotational position or amount of rotation of the drive shaft 19. A mechanical (contact) angle sensor can be realized by using a variable resistor whose electrical resistance changes in proportion to the rotation angle. The angle sensor attached to the drive shaft 19 determines that the bogie link angle θ=0 when the rotation centers of the front wheel 1a, the middle wheel 1b, and the rear wheel 1c are all on the same axis. The angle sensor attached to the drive shaft 19 is capable of acquiring the bogie link angle θ in either case when the angle of the bogie link 2 is controlled by the bogie link control motor 17 or when a free junction is in progress. The angle sensor attached to the drive shaft 19 acquires an angle by controlling the bogie link angle θ so that the direction in which the front wheel 1a connected to the bogie link 2 is positioned above the middle wheel 1b is positive polarity, and the direction in which the front wheel 1a is positioned below the middle wheel 1b is negative polarity. The angle sensor attached to the drive shaft 19 may be an optical angle sensor that measures in conjunction with the rotation of the bogie link shaft, or it may be a magnetic type such as a Hall sensor, an inductive type, or a potentiometer type. If the angle sensor attached to the drive shaft 19 is an optical type, a code wheel can be used on the drive shaft 19 to detect the amount of rotation by light passing through slits provided in the radial direction of the rotating disk. If the angle sensor attached to the drive shaft 19 is a magnetic type, the rotational position can be detected by reading the change in the magnetic field distribution created by the permanent magnet attached to the drive shaft 19 with the magnetic sensor.

[0033] FIG. 4 is a functional block diagram showing the rocker bogie car travel control unit 30 in this embodiment. The rocker bogie vehicle driving control unit 30 includes a current position acquisition unit 31, a target position acquisition unit 32, an arrival determination unit 33, a step presence / absence determination unit 34, a step crossing operation control unit 35, and a bogie link control unit 36.

[0034] FIG. 5 is a flowchart showing the autonomous driving operation of the rocker bogie vehicle 10 according to this embodiment. First, when the rocker bogie vehicle 10 starts autonomous driving, the arrival determination unit 33 compares the current position of the rocker bogie vehicle 10 acquired by the current position acquisition unit 31 with the target position acquired by the target position acquisition unit 32 to determine whether the two match (S1). If the current position and the target position match, it is determined that the rocker bogie vehicle 10 has arrived at the target position (S1; Y), and the autonomous traveling ends. If the current position and the target position do not match, it is determined that the rocker bogie vehicle 10 has not arrived at the target position (S1; N), and the step presence / absence determination unit 34 determines whether or not there is a step in the direction of travel of the rocker bogie vehicle 10 based on the detection results of the 3D camera 18 (S2). If it is determined that there is no step in the traveling direction (S2; N), the rocker-bogie vehicle 10 continues autonomous traveling by returning to S1. If it is determined that there is a step in the direction of travel (S2; Y), the step-crossing operation control unit 35 outputs a drive command to the bogie link control motor 17 to instruct the bogie link control unit 36 ​​to lift the bogie link 2, and the rocker bogie vehicle 10 performs the step-crossing operation (S3). Here, the step-over-step operation is an operation of lifting the front wheel 1a higher than the step and climbing onto the step. After the step-crossing operation (S3), the process returns to S1, and the rocker-bogie vehicle 10 continues autonomous driving.

[0035] According to this embodiment, it is possible to provide a rocker bogie vehicle that can traverse steps of various heights without providing a leg length adjustment mechanism in the rocker bogie mechanism.

[0036] In addition, the rocker bogie car travel control unit 30 may be provided outside the rocker bogie car 10. When the rocker bogie car driving control unit 30 is provided outside the rocker bogie car 10, a communication unit is provided in the rocker bogie car 10, and the communication unit is connected to the bogie link control motor 17, the 3D camera 18, and the angle sensor provided on the drive shaft 19.

[0037] Furthermore, the rocker bogie vehicle 10 according to this embodiment is premised on autonomous driving, but it may be configured to be not only autonomous driving but also remotely controllable.

[0038] <Embodiment 2> In this embodiment, a method for detecting the distance to the rocker bogie vehicle 10 will be described. As described in the first embodiment, the rocker bogie vehicle 10 according to this embodiment is equipped with a 3D camera 18 at the upper center. This 3D camera 18 detects obstacles ahead of the rocker bogie car 10 while it is traveling. When the rocker bogie vehicle 10 detects a step ahead while traveling on a flat ground, it determines whether or not the detected step can be traversed. If the step in front is a wall or the drop is unknown, the rocker bogie vehicle 10 determines that it cannot traverse the step, i.e., cannot travel, and avoids traversing the step. Alternatively, the rocker bogie vehicle 10 detects the distance to the step in front, the rise height of the step, or the rise height (depth) of the downward step, and moves up or down by controlling the front wheel position using bogie link control, and traverses the step using wheel drive control.

[0039] FIG. 6 is a diagram illustrating a method for detecting a step of the rocker bogie vehicle 10 according to this embodiment. As shown in Figure 6, by using the positional relationship between the 3D camera 18 equipped on the rocker bogie vehicle 10 and the front wheel 1a and the distance data measured by the 3D camera 18, it is possible to detect an uphill step in front of the rocker bogie vehicle 10 and calculate the distance L to the uphill step. In this embodiment, image data and depth (distance) are measured.

[0040] FIG. 6(A) is a diagram illustrating a method for detecting an upward step of the rocker-bogie vehicle 10 according to this embodiment. The 3D camera 18 can capture images in front of the rocker bogie car 10 and acquire distance data using the ToF method. The rocker bogie vehicle 10 can detect discontinuous points (hereinafter referred to as edges) by detecting the continuity of distance in the traveling direction. The distance L from the tip of the front wheel 1a of the rocker bogie vehicle 10 to this edge can be calculated as L = L2 - L1 based on the distance L1 from the 3D camera 18 to the tip of the front wheel 1a, which is known by design, and the distance data obtained by the ToF method (distance L2 from the 3D camera 18 to the edge). When detecting an uphill step, the 3D camera 18 detects an edge, and if the distance data beyond the detected edge is in a direction that is closer (shorter), it can be detected that the step in front of the rocker bogie vehicle 10 is an uphill step.

[0041] Expressed using the Depth data in Figure 3, from the data group of distance Depthlx,y, for the distance zp to the bottom of the step in front of the rocker bogie vehicle 10, the rising part of the step rises in the x-axis direction, and if the resolution in the x-axis direction is 640, the x-axis scanning data is z(0,y) to z(639,y). Furthermore, if the resolution in the y-axis direction is 480, the y-axis scanning data will be z(x,0) to z(x,479).

[0042] FIG. 6(B) is a diagram illustrating a method for detecting a downward step of the rocker bogie vehicle 10 according to this embodiment. The distance L from the tip of the front wheel 1a of the rocker bogie vehicle 10 to the edge of the downward step can be calculated as L = L2 - L1 based on the distance L1 from the 3D camera 18 to the tip of the front wheel 1a and the distance L2 from the 3D camera 18 to the edge, similar to the detection of an upward step. When detecting a downward step, an edge is detected using the 3D camera 18, and if the distance data beyond the detected edge is moving away (getting longer), it can be detected that the step in front of the rocker bogie vehicle 10 is a downward step.

[0043] FIG. 7A is a diagram illustrating the continuity of distance data for detecting a step (edge). The two plane positions when the running surface of the rocker bogie car 10 is scanned by the 3D camera 18 are represented as pi,j and pi,j+1. Although it depends on the specifications of the 3D camera 18, as an example, the resolution of the y axis is n, and the camera is attached at an azimuth angle of ±φ with respect to the horizontal (the elevation angle is positive and the depression angle is negative). That is, the number of scanning lines emitted from the 3D camera 18 is n, and the minimum irradiation angle of each is expressed as 2φ / n. The scan lines Dj are D0 to Dj. Here, the maximum value of j is 479.

[0044] The intersection point of the scanning line on the horizontal plane is represented as pi,j, and when only the y-axis plane at any point i in the x-axis direction is considered, the angle between the scanning line and the vertical line is (90-φ). The angle of the scanning line Dj with the vertical line is αj=(90-φ)+2φ / n*j. where 0 <j<nである。

[0045] FIG. 7B is a diagram showing the geometric relationship of FIG. 7A. As shown in FIG. 7B, if the angle of this scanning line from the vertical line is αj, the distance bj of the base can be calculated by the following formula (1) using the law of cosines.

[0046]

number

[0047] Furthermore, the intersection Pi,j between the plane and the scanning line Dij is expressed by the following equation (2).

[0048]

number

[0049] Similarly, when the next scanning line Di,j+1 on the y-axis is considered, the intersection Pi,j+1 between the plane and the scanning line Di,j+1 is expressed by the following equation (3).

[0050]

number

[0051] Regarding the intersection point Pi,j calculated by the above formula (2) and the intersection point Pi,j+1 calculated by the formula (3), Pi,j<Pi,j+1となるべきところでPi,j> If Pi,j+1, an edge exists (first method in the second embodiment).

[0052] As another method, Figure 7(B) shows a right triangle (angles α, γ, β, sides a, b, c) formed by height a, which is the position of the 3D camera 18, and forward distance b of the running surface from the vertical line of the 3D camera 18, where height a is known data, and when the scanning line Di,j of the 3D camera 18 scans, the distance to the point where the scanning line Di,j intersects with the horizontal surface, which is the opposite running surface, at angle αi,j in the y-axis direction is expressed as bi,j. The angle β of the right triangle in this case can be expressed as follows: The angle βi,j at the point where the horizontal plane Di,j, which is the running plane of the ith scan on the x-axis and the jth scan on the y-axis, intersects is a triangle whose sum of the interior angles is 180°, and the angle αj of the aforementioned scanning line Dj with the vertical line is αj = (90 - φ) + 2φ / n * j, so αi,j is a known angle determined by j. Therefore, βi,j = 180° - αi,j - 90°, which is known.

[0053]

number

[0054] The calculated value bi,j calculated by the above formula (4) is compared with the detected measured value bi,j, and if they differ, an edge exists (second method in the second embodiment). As described above, by using the first or second method in this embodiment, the scanning data is evaluated in the y-axis direction to detect a step (edge), and the distance bj from the tip of the front wheel 1a of the rocker bogie vehicle 10 to the step (edge), that is, the distance L, is calculated.

[0055] Next, detection of the height H of the upward step will be described. FIG. 8(A) is a diagram showing parameters when detecting an upward step of the rocker-bogie vehicle 10 according to this embodiment. The 3D camera 18 can acquire distance data using the ToF method. The height a of the camera position of the rocker bogie car 10 is known information. By detecting edges from the distance-measured camera image as described above, the 3D camera 18 can detect the edge between the riser vertical surface (riser) of the step ahead in the direction of travel and the flat ground, and can calculate the distance c to this edge. Furthermore, when the second edge is detected from the continuity information of the depth distance measurement of the measured camera image, the edge between the riser vertical surface (riser board), the flat ground, and the tread of the upward step can be detected, and the distance c1 to this edge can be calculated. According to the Pythagorean theorem, the distance b from the 3D camera 18 to the vertical surface of the riser (riser board) can be expressed by the following equation (5) using the distance c to the edge of the bottom of the riser board.

[0056]

number

[0057] Similarly, the height difference length a1 between the tread on the upward step and the camera position can be expressed by the following equation (6) using the distance c1 between the edge of the rise vertical surface (riser) of the upward step and the tread of the upward step.

[0058]

number

[0059] The step height x is calculated by the following formula (7) using the height a of the camera position, the distance c, and the distance c1. The step height x corresponds to the rise height H of the upward step.

[0060]

number

[0061] Next, detection of the height H of the downward step will be described. FIG. 8(B) is a diagram showing parameters when the rocker-bogie vehicle 10 according to this embodiment detects a downward step. The 3D camera 18 detects edges from the distance-measured camera image as described above, thereby detecting the edge between the step ahead in the traveling direction and the flat ground, and is also able to calculate the distance c to this edge. Furthermore, the distance c1 beyond the edge can be calculated from the continuity of the depth distance measurement of the camera image. Using the step height x, the height a of the camera position, the distance b1 from the camera passing through the edge to the point where it reaches the flat ground beyond the edge, and the distance c1, the following equation (8) is established.

[0062]

number

[0063] The step height x is calculated from the geometric relationship using the following formula (9). The step height x corresponds to the rise height H of the downward step, which is the depth.

[0064]

number

[0065] As described above, according to this embodiment, the distance to the step and the height of the step can be detected.

[0066] <Embodiment 3> In this embodiment, a description will be given of step traversal by controlling the bogie link 2 of the rocker bogie vehicle 10.

[0067] FIG. 9 is a diagram showing parameters of the rocker bogie vehicle 10 according to this embodiment. In Figure 9, the rocker bogie vehicle 10 is located on flat ground and the bogie link angle θ = 0, so the center of the front wheel 1a, the center of the middle wheel 1b, and the center of the rear wheel 1c are all located on the front-middle-rear wheel coaxial line shown in Figure 9. The wheel diameter r1 is the radius of the front wheel 1a. The wheel diameter r2 is the radius of the middle wheel 1b. The wheel diameter r3 is the radius of the rear wheel 1c. FIG. 9 shows the case where r1=r2=r3. The length L1 is the length from the center position of the rotation axis of the bogie link 2, where the drive shaft 19 is located, to the center of the front wheel 1a. The length L2 is the length from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the middle wheel 1b. The angle φ1 is the angle formed by a line segment (line segment of length L1) from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the front wheel 1a and a vertical line. The angle φ2 is the angle formed by the line segment (line segment of length L2) from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the middle wheel 1b and the vertical line. The length L3 is the distance from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the rear wheel 1c in a direction perpendicular to the plumb line (a direction parallel to the flat ground). The length L4 is the distance in the vertical direction (direction perpendicular to the flat ground) from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the rear wheel 1c. The length a1 is the distance from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the front wheel 1a in a direction perpendicular to the plumb line (a direction parallel to the flat ground). The length a2 is the distance from the center position of the rotation axis of the bogie link 2 where the drive shaft 19 is located to the center of the middle wheel 1b in a direction perpendicular to the plumb line (a direction parallel to the flat ground).

[0068] FIG. 10 is a diagram showing a state in which the front wheel 1a of the rocker bogie vehicle 10 according to this embodiment is lifted. In FIG. 10, the ground plane is inclined, but this is for the purpose of explanation that will be given later. In reality, the ground plane is horizontal in the absolute coordinate system, just like in FIG. As shown in FIG. 10, the bogie link 2 is driven and rotated at a drive angle θ, so that the front wheels 1a are lifted from the flat ground to a front wheel height h. The front wheel height h is the distance from the flat ground to the center of the front wheel 1a in the vertical direction (direction perpendicular to the flat ground). The front wheel height h is set to a height that allows the rocker bogie car 10 to ride over the step height H in front of the car.

[0069] FIG. 11 is a diagram for explaining the positional relationship in a state in which the front wheel 1a of the rocker bogie vehicle 10 according to this embodiment is lifted. In FIG. 11, in addition to the original front-center-rear wheel coaxial line passing through the rear wheel 1c, a center-rear wheel coaxial line connecting the center of the center wheel 1b and the center of the rear wheel 1c is shown. Here, the following positional relationship is defined with the rear wheel 1c at the center. The length r is the distance from the flat ground on the vertical line (the line in the direction of gravity of the front wheels) to the intersection with the center rear wheel coaxial line. The length q is the length from the intersection of the vertical line with the central-rear wheel coaxial line to the intersection with the front-central-rear wheel coaxial line. The length p is the length from the intersection of the vertical line with the coaxial line of the front, middle and rear wheels to the center of the front wheel.

[0070] The angle α is the angle formed by the center-rear wheel coaxial line and the original front-center-rear wheel coaxial line passing through the rear wheel 1c. The front wheel height h can be expressed by the following equation (10) using the lengths p, q, r and angle α.

[0071]

number

[0072] FIG. 12(A) is a diagram showing the displacement of the front wheel 1a of the rocker bogie vehicle 10 according to this embodiment when the front wheel 1a is lifted. As shown in FIG. 12(A), the front wheel 1a is tilted by controlling the bogie link angle θ, causing a displacement in the length f value and the length p value. Here, the length f value is the length in the x-axis direction from the bogie link axis to the center of the front wheel 1a after displacement when the front wheel 1a is lifted by controlling the bogie link angle θ. Furthermore, the length p value is the length from the center of the front wheel 1a to the intersection of the vertical line and the coaxial line of the front, middle and rear wheels before controlling the bogie link angle θ when the front wheel 1a is lifted by controlling the bogie link angle θ.

[0073] FIG. 12B is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 12A. The length p value is expressed by the following formula (11).

[0074]

number

[0075] Similarly, the length f value is expressed by the following equation (12).

[0076]

number

[0077] FIG. 13(A) is a diagram showing the displacement of the middle wheel 1b when the front wheel 1a of the rocker bogie vehicle 10 according to this embodiment is lifted. As shown in FIG. 13(A), the center wheel 1b is tilted by controlling the bogie link angle θ, causing displacements in the length e value and the length d value. Here, the length e is the length of displacement of the center of the middle wheel 1b in the x-axis direction when the front wheel 1a is lifted by controlling the bogie link angle θ. The length d is the length of displacement of the center of the middle wheel 1b in the vertical direction when the front wheel 1a is lifted by controlling the bogie link angle θ.

[0078] FIG. 13B is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 13A. The length d value is expressed by the following formula (13).

[0079]

number

[0080] Similarly, the length e value is expressed by the following equation (14).

[0081]

number

[0082] FIG. 14A is a diagram for explaining the calculation of the angle α. As shown in FIG. 14(A), the angle α is the angle formed by the central-rear wheel coaxial line parallel to the flat ground and the original front-central-rear wheel coaxial line passing through the rear wheel 1c. As shown in FIG. 14(A), here, the front wheel 1a is lifted and the middle wheel 1b is displaced forward.

[0083] FIG. 14(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 14(A). From the geometric relationship shown in FIG. 14(B) and equations (13) and (14), the angle α is expressed by the following equation (15).

[0084]

number

[0085] FIG. 15(A) is a diagram for explaining the calculation of the length q. FIG. 15(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 15(A). From the geometric relationship shown in FIG. 15(B) and equations (12) and (15), the length q is expressed by the following equation (16).

[0086]

number

[0087] FIG. 16(A) is a diagram for explaining the calculation of the length r. FIG. 16B is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 16A when r2>r3. FIG. 17 is a diagram supplementing the geometric relationship in FIG. 16(B). Here, the geometric relationship is represented by a trapezoid. For the trapezoid shown in FIG. 16(B), the following parameters are defined. The length u is the length from the intersection of a vertical line passing through the center of the middle wheel 1b and the center rear wheel coaxial line to the center of the rear wheel 1c. The length t is the length from the intersection of the vertical line passing through the center of the front wheel 1a and the central rear wheel coaxial line to the center of the rear wheel 1c. The length R2 is the length from the intersection of the vertical line passing through the center of the middle wheel 1b and the flat ground to the center of the middle wheel 1b. The length R3 is the length from the intersection of a vertical line passing through the center of the rear wheel 1c and the flat ground to the center of the rear wheel 1c. The length r is the distance from the intersection of the vertical line passing through the center of the front wheel 1a and the central rear wheel coaxial line to the flat ground. Here, the wheel diameter r2 is the radius of the middle wheel 1b, and the wheel diameter r3 is the radius of the rear wheel 1c, and these are known values. When the wheel diameters of the middle and rear wheels are the same (r2 = r3), a parallelogram is formed with the middle and rear wheels coaxial, as shown in Figure 16(A). As a general condition, when expressed with different radii, it becomes a trapezoid shape as shown in FIG. Within this trapezoid, r can be expressed as follows using the relationship based on the similarity conditions for triangles. The length r is expressed by the following equation (17).

[0088]

number

[0089] FIG. 18A is a diagram for explaining the calculation of the length t and the length u. FIG. 18(B) is a diagram showing the geometric relationship obtained by extracting the parameters shown in FIG. 18(A). From the geometric relationship shown in FIG. 18(B) and equation (12), the length t is expressed by the following equation (18) using the length L3 and the angle α.

[0090]

number

[0091] The length u is expressed by the following equation (19) using the lengths L2, L3 and a2 according to the geometric relationship shown in FIG. 18(B) and equation (14).

[0092]

number

[0093] Therefore, by substituting equations (18) and (19) into equation (17), the length r is expressed by the following equation (20).

[0094]

number

[0095] The front wheel height h expressed by equation (10), the length p expressed by equation (11), the length q expressed by equation (16), the length r expressed by equation (20), and the angle α expressed by equation (15) can be summarized as shown in the following equation group (21).

[0096]

number

[0097] In the above equation group (21), the length p, the length q, the length r, and the angle α are all functions of θ, and can therefore be expressed as p(θ), q(θ), r(θ), and α(θ), respectively. Therefore, the height G(θ) from the wheel edge of the front wheel 1a to the horizontal plane is expressed by the following equation (22) after subtracting the wheel diameter r1.

[0098]

number

[0099] Introducing a constant term K that indicates the influence of external factors such as friction, the front wheel height h when the rocker bogie car 10 is driven at a bogie link angle ω is w is expressed by the following equation (23). The constant term K is an extremely small value.

[0100]

number

[0101] Therefore, the condition for the front wheel 1a to overcome the step H is expressed by the following equation (24).

[0102]

number

[0103] As explained in this embodiment, the front wheel height h w When this is set, the front wheel 1a can overcome the step H.

[0104] <Embodiment 4> In this embodiment, the rocker bogie vehicle 10 will be described as traveling over an upward step. FIG. 19 is a diagram showing a state in which the rocker-bogie vehicle 10 according to this embodiment detects an upward step in front of it and lifts the front wheel 1a at a drive angle ω. The rocker bogie vehicle 10 according to this embodiment acquires distance data in front using the 3D camera 18 as described in the first to third embodiments, and detects a step in front based on this distance data. The rocker bogie vehicle 10 acquires the step height H and the distance L from the tip of the front wheel 1a to the step based on the distance data as described in the second embodiment.

[0105] As described in the third embodiment, the rocker bogie vehicle 10 has a front wheel height h w While lifting the front wheel 1a, the middle wheel 1b and rear wheel 1c rotate to move the rocker bogie car 10 forward. Front wheel height h w is expressed by the sum of the height G(θ) from the wheel edge of the front wheel 1a to the horizontal plane and a constant term K, as shown in equation (23) of the third embodiment. The constant term K indicates the influence of external factors such as friction, and indicates the influence of friction and the weight of the arm on the motor. As shown in the equation (24) of the third embodiment, the rocker bogie vehicle 10 has a front wheel height h w is greater than the step height H, i.e., h w It is necessary to be able to lift the front wheel 1a so that >H and maintain this state.

[0106] FIG. 20 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where it has moved forward from FIG. 19 so that the front wheels 1a are above the step. Rocker bogie car 10, h w In the state of >H, the middle wheel 1b and the rear wheel 1c are driven to move forward until L≦0, so that the front wheel 1a can be positioned above the step.

[0107] FIG. 21 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the front wheel 1a comes into contact with a step as shown in FIG. The rocker bogie vehicle 10 can make the front wheels 1a contact the step by controlling the drive angle ω, that is, the angle command to the bogie link 2.

[0108] FIG. 22 is a diagram showing a state in which the angle of the bogie link is controlled to lift the middle wheel 1b from the state shown in FIG. As shown in FIG. 22, by further increasing the drive angle ω, that is, the angle command to the bogie link 2, the center wheel 1b can be lifted with the front wheel 1a as the fulcrum. In FIG. 22, the middle wheel 1b is raised to the same height as the front wheel 1a, but the present invention is not limited to this, and the middle wheel 1b may be raised to a position higher than the front wheel 1a. The rocker bogie car 10 can raise the middle wheels 1b to a height equal to or higher than the height of the front wheels 1a by controlling the drive angle ω, that is, the angle command to the bogie link 2. At this time, the angle command to the bogie link 2 is set to an angle command Δω. The angle command Δω can be calculated from the dimensions of the rocker bogie vehicle 10 and the step height H, but the present invention is not limited to this. A sensor for detecting the horizontal state of the bogie link 2 may be provided on the bogie link 2, and the angle command Δω may be controlled so that the bogie link 2 is horizontal.

[0109] FIG. 23 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the middle wheel 1b has gone over the step from FIG. 22 and has moved forward. The rocker bogie car 10 has a center wheel 1b with a front wheel height h w With the vehicle lifted to this level, the front and rear wheels 1a and 1c are driven to move the vehicle forward, thereby allowing the middle wheel 1b to be positioned above the step. The bogie link 2 is in a free junction state when the middle wheel 1b is positioned above the step. At this time, the middle wheel 1b is in contact with the upper surface of the step, so it may be driven forward.

[0110] FIG. 24 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the rear wheels 1c are in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10 drives the front wheels 1a, the middle wheels 1b and the rear wheels 1c to move forward from FIG. 23 until the rear wheels 1c come into contact with the riser vertical surface (riser board). The rocker bogie vehicle 10 moves further forward with the rear wheels 1c in contact with the riser vertical surface (riser plate), and when the condition Fr+P>Wg is met between the driving force Fr of the rear wheels 1c, the friction force P of the riser vertical surface (riser plate) due to the force moving forward, and the effect Wg of the rear wheels' own weight on the rear wheels 1c, the rear wheels 1c can also overcome the step.

[0111] FIG. 25 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the vehicle has moved further forward from the state shown in FIG. 24 and the rear wheels 1c have climbed over a step. If the area above the step is flat, the rocker bogie vehicle 10 can detect that the rear wheel 1c has passed over the step by the bogie link 2 becoming horizontal.

[0112] As described in this embodiment, the rocker bogie vehicle 10 can overcome steps that exist ahead in the traveling direction.

[0113] <Embodiment 5> In this embodiment, the rocker bogie vehicle 10 will be described as traveling over an upward step. In the fourth embodiment, the center wheel 1b is positioned at the front wheel height h of the front wheel 1a. w Although the above description has been given of the form in which the device is lifted up in advance, the present invention is not limited to this. This embodiment differs from the fourth embodiment in the lifting of the middle wheel 1b.

[0114] First, as shown in FIG. 19, in this embodiment, as in the fourth embodiment, the rocker bogie vehicle 10 detects a step in front of it and lifts the front wheel 1a at a drive angle ω.

[0115] FIG. 26 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the middle wheel 1b is in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10 moves forward from FIG. 19 until the front wheels 1a are on the step, and then the front wheels 1a are brought into contact with the step. With the front wheels 1a in contact with the step, the front wheels 1a, middle wheels 1b, and rear wheels 1c are driven, and the vehicle moves forward by driving the front wheels 1a, middle wheels 1b, and rear wheels 1c until the middle wheels 1b come into contact with the riser vertical surface (riser board).

[0116] FIG. 27 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state in which the middle wheel 1b is in contact with the riser vertical surface (riser plate) and raised from the state shown in FIG. The rocker bogie vehicle 10 moves further forward with the middle wheel 1b in contact with the riser vertical surface (riser plate), and when the condition Fr+P>Wg is met between the driving force Fr of the middle wheel 1b, the friction force P of the riser vertical surface (riser plate) due to the force moving forward, and the effect Wg of the middle wheel 1b's own weight, the middle wheel 1b can overcome the step. At this time, the angle command to the bogie link 2 may be in a free junction state, but the angle command to the bogie link 2 may be an angle command Δω so as to support the friction force P. The angle command Δω is controlled so that the center wheel 1b maintains a state in which it is in contact with the riser vertical surface (riser plate).

[0117] FIG. 28 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. As shown in FIG. 27, the rocker bogie vehicle 10 can move forward by driving the front wheels 1a, the middle wheels 1b, and the rear wheels 1c, thereby making the middle wheels 1b contact the step.

[0118] The subsequent operations are the same as those in the fourth embodiment, and have been explained with reference to FIGS. 23 to 25 in the fourth embodiment, so explanations thereof will be omitted here.

[0119] As described in this embodiment, the rocker bogie vehicle 10 can overcome steps that exist ahead in the traveling direction.

[0120] <Embodiment 6> In this embodiment, the rocker bogie vehicle 10 will be described as traveling over a downward step. In this embodiment, the rocker bogie car 10 descends a step by utilizing the frictional force of the riser vertical surface (riser plate) of the step.

[0121] FIG. 29 is a diagram showing the rocker bogie vehicle 10 according to this embodiment when detecting a downward step. When the rocker bogie vehicle 10 detects a downward step ahead in the direction of travel, it acquires the step height H and the distance L from the tip of the front wheel 1a to the step based on the distance data, as in the fourth embodiment.

[0122] FIG. 30 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. As shown in FIG. 30, the rocker bogie vehicle 10 moves forward to the edge of the downward step, that is, until the distance L becomes equal to the radius r1 of the front wheel 1a, that is, until L=r1.

[0123] FIG. 31 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the front wheels 1a are in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10 moves the front wheels 1a from the state shown in Figure 30 to the edge of the downward step, and when the front wheels 1a start to descend from the edge of the downward step, the middle wheels 1b and rear wheels 1c are rotated in the direction in which the rocker bogie vehicle 10 moves backward. As a result, a force Fω is generated between the front wheel 1a and the riser vertical surface (riser) of the step. The force Fω increases the friction force P on the riser vertical surface (riser board). The front wheel 1a can descend a step when the condition Fr+Wg>P is met between the force Fr exerted in the forward direction of the front wheel 1a, the friction force P of the riser vertical surface (riser board), and the weight Wg of the front wheel 1a.

[0124] FIG. 32 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the front wheels 1a are further lowered from the state shown in FIG. The rocker bogie vehicle 10 allows the front wheels 1a to reach the lower stage by loosening the torque of the middle wheels 1b and rear wheels 1c as shown in FIG.

[0125] FIG. 33 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. As shown in Figure 32, when the front wheel 1a reaches the lower surface, the front wheel 1a continues to rotate in the direction in which the rocker bogie car 10 moves forward, while the middle wheel 1b and rear wheel 1c reverse and rotate in the direction in which the rocker bogie car 10 moves forward.

[0126] FIG. 34 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the middle wheel 1b is in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10, like the front wheel 1a, makes the middle wheel 1b reach the edge of the downward step, and when the middle wheel 1b starts to descend from the edge of the downward step, the front wheel 1a and the rear wheel 1c are rotated in the direction in which the rocker bogie vehicle 10 moves backward. As a result, a force Fω is generated between the center wheel 1b and the riser vertical surface (riser plate) of the step. The middle wheel 1b, like the front wheel 1a, gradually descends by utilizing the frictional force P of the riser vertical surface (riser) of the step. The rocker bogie vehicle 10 reduces the torque of the front wheels 1a and rear wheels 1c, thereby allowing the middle wheels 1b to reach the lower stage.

[0127] FIG. 35 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. When the middle wheel 1b reaches the lower surface, the middle wheel 1b continues to rotate in the direction in which the rocker bogie car 10 moves forward, while the front wheel 1a and rear wheel 1c reverse and rotate in the direction in which the rocker bogie car 10 moves forward.

[0128] FIG. 36 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the rear wheels 1c are in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10, like the front wheels 1a and the middle wheels 1b, makes the rear wheels 1c reach the edge of the downward step, and when the middle wheels 1c start to descend from the edge of the downward step, the front wheels 1a and the middle wheels 1b are rotated in the direction in which the rocker bogie vehicle 10 moves backward. As a result, a force Fω is generated between the rear wheel 1c and the riser vertical surface (riser) of the step. The rear wheel 1c, like the front wheel 1a and the middle wheel 1b, gradually descends by utilizing the frictional force P of the riser vertical surface (riser) of the step. The rocker bogie vehicle 10 allows the rear wheel 1c to reach the lower stage by loosening the torque of the front wheel 1a and the middle wheel 1b.

[0129] FIG. 37 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. When the rear wheel 1c reaches the lower surface, the rear wheel 1c continues to rotate in the direction in which the rocker bogie car 10 moves forward, while the front wheel 1a and the middle wheel 1b reverse and rotate in the direction in which the rocker bogie car 10 moves forward.

[0130] As described in this embodiment, the rocker bogie vehicle 10 can descend steps that exist ahead in the traveling direction.

[0131] <Embodiment 7> In this embodiment, the rocker bogie vehicle 10 will be described as traveling over a downward step. In the sixth embodiment, the rocker bogie vehicle 10 descends a step by controlling the rotation of the front wheels 1a, the middle wheels 1b, and the rear wheels 1c, but the present invention is not limited to this. In this embodiment, a mode in which the rocker bogie car 10 descends a step by controlling the bogie link 2 will be described.

[0132] First, as shown in FIG. 29, in this embodiment, as in embodiment 6, when the rocker bogie vehicle 10 detects a downward step ahead in the direction of travel, the step height H and the distance L from the tip of the front wheel 1a to the step are obtained based on the distance data. Then, as shown in FIG. 30, the rocker bogie vehicle 10 moves forward to the edge of the downward step, that is, until the distance L becomes equal to the radius r1 of the front wheel 1a, that is, until L=r1.

[0133] FIG. 38 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the front wheels 1a are in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie vehicle 10 brings the front wheels 1a to the edge of the downward step from the state shown in Figure 30, and by applying a driving force to the bogie link 2 at a constant speed, a force Fω is generated that presses the front wheels 1a against the riser vertical surface (riser) of the step. The frictional force P, which is a reaction force, increases as the pressing force Fω increases. The front wheel 1a can descend a step when the condition Fr+Wg>P is met between the force Fr exerted in the forward direction of the front wheel 1a, the friction force P of the riser vertical surface (riser board), and the weight Wg of the front wheel 1a.

[0134] FIG. 39 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the front wheels 1a have further descended from FIG. 38 and reached the lower stage. When the front wheels 1a of the rocker bogie car 10 reach the lower stage, the bogie link 2 is fixed at the angle at which it reaches the lower stage.

[0135] FIG. 40 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state further forward from that shown in FIG. The rocker bogie car 10 rotates the front wheels 1a and rear wheels 1c in the direction in which the rocker bogie car 10 moves forward while the bogie link 2 is fixed at the angle at which it reaches the lower stage, so that the middle wheels 1b are in a floating state.

[0136] FIG. 41 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the angle of the bogie link 2 is reduced from that shown in FIG. By reducing the driving force applied to the bogie link 2, the middle wheel 1b descends and touches the ground on the lower level. The state at this time is the state shown in FIG. 35 of the sixth embodiment. When the middle wheel 1b of the rocker bogie car 10 touches the ground at the lower stage, the bogie link 2 is put into a free junction state.

[0137] FIG. 42 is a diagram showing the rocker bogie vehicle 10 according to this embodiment in a state where the rear wheels 1c are in contact with the vertical riser surface after moving further forward from the state shown in FIG. The rocker bogie car 10 rotates the front wheels 1a, middle wheels 1b, and rear wheels 1c slowly in the direction in which the rocker bogie car 10 moves forward, and the rear wheels 1c gradually descend due to the frictional force of the riser vertical surface (riser board) of the step. However, the present invention is not limited to this, and as in embodiment 6, when the rear wheels 1c start to descend from the edge of the downward step, the front wheels 1a and middle wheels 1b are rotated in the direction in which the rocker bogie car 10 moves backward, and the torque of the front wheels 1a and middle wheels 1b is loosened, so that the rear wheels 1c can reach the lower step. When the rear wheels 1c reach the lower surface, the front wheels 1a, the middle wheels 1b and the rear wheels 1c rotate in the direction in which the rocker bogie car 10 moves forward.

[0138] As described in this embodiment, the rocker bogie vehicle 10 can descend steps that exist ahead in the traveling direction.

[0139] <Embodiment 8> In this embodiment, a case where the rocker bogie vehicle is not directly facing the step will be described. In distance measurement using a 3D LIDAR or 3D camera (ToF), for example, the scan line scans from the front left edge to the front right edge. It is possible to measure in all directions (360°) on the horizontal plane, or to measure only a portion of the area in front. This measurement range is expressed as the angle of view in the forward left and right directions. In two-dimensional coordinates of x and y on a horizontal plane, two points on the x axis can be expressed as pi,j and pi+1,j. The 3D camera 18 is mounted with a resolution m, with a vertical plane (two-dimensional coordinates of x and y) at azimuth angles ±z (horizontal angle of view 2z) to the left and right of the front. The number of scanning lines Di is m, and each irradiation angle is expressed as 2z / m. If the resolution is m=640, the scanning lines Di are numbered D0 to D 639 It is expressed as: Let the displacement be i in the x-axis direction and j in the y-axis direction. If the horizontal intersection point of the scanning line at the bottom of the step is expressed as pi,j, the position of the center front of the rocker bogie car is i=320.

[0140] FIG. 43 is a diagram showing the top surface of the rocker bogie vehicle 10 facing the step in front of the running direction according to this embodiment. In FIG. 43, the length from the center of the left and right wheels of the body of the rocker bogie car 10 is defined as the wheel width a, and the width of the car body is defined as the wheel width a×2. Distance to step L L ,L R Once calculated, x=L L cosθ L , x=L R cosθ R θ where x is the wheel width a L ,θ R The points Di and Dn are the step points in front of the left and right front wheels. From the right and left right triangles with the step points Di and Dn as vertices, the angle θ is calculated using the following equations (25) and (26). L and angle θ R Calculate and compare.

[0141]

number

[0142]

number

[0143] θ L =θ R In this state, the rocker bogie 10 faces the step. θ L <θ R In this case, there is a step further forward on the right side of the rocker bogie car 10 than on the left side. θ L >θ R In this case, there is a step further forward on the left side of the rocker bogie car 10 than on the right side. θ L =θ RSince the rocker bogie vehicle 10 in this example faces the step in front of it, the distance to the step ahead can be calculated. In this way, the distance to the step can be calculated from the front of the left and right wheels, so that the step can be traversed as described in the other embodiments.

[0144] On the other hand, θ L ≠θ R In this case, as described in embodiment 1, in the rocker bogie vehicle 10 according to this embodiment, the right front wheel 1aR, the left front wheel 1aL, the right rear wheel 1cR and the left rear wheel 1cL are Mecanum wheels (registered trademark), and the right middle wheel 1bR and the left middle wheel 1bL are Omni wheels (registered trademark), so the vehicle changes direction to face the step ahead in the detected direction of travel. FIG. 44 is a diagram showing the top view of the rocker bogie vehicle 10 shown in FIG. 43 when the direction is changed so that the vehicle faces the step. The rocker bogie vehicle 10 traverses the step while facing the step as shown in FIG.

[0145] According to this embodiment, the rocker bogie vehicle can traverse the step even if it is not facing the step directly.

[0146] <Embodiment 9> In this embodiment, a case where the rocker bogie vehicle 10 is not directly facing the step, as in the eighth embodiment, will be described. In embodiment 8, the rocker bogie vehicle 10 changes direction to face the step ahead in the detected direction of travel, and traverses the step. However, in the rocker bogie vehicle 10 according to this embodiment, the left and right wheels traverse the step independently.

[0147] Distance L from the left front wheel 1aL of the rocker bogie car 10 to the step L_1a is calculated by the following equation (27), and the distance L from the right front wheel 1aR of the rocker bogie car 10 to the step R_1a is calculated by the following equation (28).

[0148]

number

[0149]

number

[0150] According to this embodiment, even if the rocker bogie vehicle is not directly facing the step, it can traverse the step by controlling the left and right sides independently.

[0151] The present invention is not limited to the above-described embodiment, but also includes various modifications in which components are added, deleted, or converted from the above-described configuration. [Explanation of symbols]

[0152] 1a Front wheel 1aR right front wheel 1aL front left wheel 1b Middle wheel 1bR Right center wheel 1bL left middle wheel 1c rear wheel 1cR right rear wheel 1cL left rear wheel 2 Bogie Link 2R Right bogey link 2L left bogie link 3 Rocker Link 3R right rocker link 3L left rocker link 5 carts 10 Rocker Bogies 14, 14R, 14L, 15, 15R, 15L, 16, 16R, 16L motor 17 Bogie link control motor 17R Right bogie link control motor 17L Left bogie link control motor 18. 3D Camera 19 Drive shaft 30 Rocker bogie car driving control unit 31 Current position acquisition unit 32 Target position acquisition section 33 Arrival determination unit 34 Step detection section 35 Step-crossing operation control unit 36 Bogie link control unit

Claims

1. A rocker bogie car with a total of six wheels, with a pair of front wheels, a pair of middle wheels, and a pair of rear wheels on the left and right, a bogie link on which the front wheels and the middle wheels are journaled; a rocker link on which the rear wheel is journaled; a main body fixed to the rocker link; a sensor that detects a step in the traveling direction and measures the distance to the step, The bogie link is pivotally supported on the main body or the rocker link and is free to rotate or dynamically rotate; The front and rear wheels are rotatably supported on the outer periphery of the main wheel at an angle of 45° to the axle and have a structure including a plurality of free wheels arranged in a circumferential direction, The center wheel is supported on the outer periphery of the main wheel so as to be rotatable at an angle of 90° to the axle, and has a structure including a plurality of free wheels arranged in a circumferential direction, When the sensor detects a step in the traveling direction, the front wheel is raised above the height of the step, The step is detected as a discontinuous point in the distance measurement of the sensor, using distance data between the discontinuous point and the sensor as a reference, when distance data between the sensor and a point measured in the travel direction from the discontinuous point becomes small, the step is detected to be an uphill step; using distance data between the discontinuous point and the sensor as a reference, when distance data between the sensor and a point measured in the traveling direction from the discontinuous point becomes large, the step is detected to be a downward step; Calculating a distance to the step based on the discontinuous point; Calculating the height of the step based on the calculated distance; A rocker bogie vehicle that calculates the height to lift the front wheels based on the step height.

2. The step is an upward step, The front wheels are raised above the step height and moved forward, and then the wheels are brought into contact with the step, Lift the middle wheel above the height of the front wheel; The rocker bogie vehicle according to claim 1, wherein the step is traversed by rotating the rear wheels along the rise vertical surface of the step.

3. The step is an upward step, The front wheels are raised above the step height and moved forward, and then the wheels are brought into contact with the step, The center wheel is rotated along the rise vertical surface of the step, The rocker bogie vehicle according to claim 1, wherein the step is traversed by rotating the rear wheels along the rise vertical surface of the step.

4. the step is a downward step, The rocker bogie vehicle according to claim 1, wherein the step is traversed by rotating the front wheels, the middle wheels, and the rear wheels sequentially along the rise vertical surface of the step.

5. the step is a downward step, The front wheels are rotated along the rise vertical surface of the step to make the front wheels contact the bottom of the step, With the angle of the bogie link fixed, the vehicle moves forward using the front wheels and the rear wheels, and then the middle wheels are brought into contact with the bottom of the step; The rocker bogie vehicle according to claim 1, wherein the step is traversed by rotating the rear wheels along the rise vertical surface of the step.

6. When the step is not directly facing the step, the rotation of the front wheels, the middle wheels, and the rear wheels is controlled so as to face the step directly, and the step is traversed in a state facing the step. The rocker bogie vehicle according to any one of claims 4 to 5.

7. 6. The rocker bogie vehicle according to claim 2, wherein when the step is not directly facing the step, the front wheels, the middle wheels, and the rear wheels are controlled independently on the left and right sides to traverse the step.

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