Connected vehicles

Abstract

The present invention provides a coupling vehicle capable of detecting the relative angle of a towed vehicle to a towing vehicle without requiring the towed vehicle to be equipped with markers for detecting the relative angle with respect to the towing vehicle. [Solution] The coupled vehicle 1 comprises a towing vehicle 2, a towed vehicle 3, a towing-side coupling member 4 provided on the towing vehicle 2, a towed-side coupling member 5 provided on the towed vehicle 3 and connected to the towing-side coupling member 4, an imaging device 61 attached to the towed vehicle 3 for imaging the towing vehicle 2, and a processing unit 62 that calculates the relative angle of the towed vehicle 3 with respect to the towing vehicle 2 based on the positions of feature points of the towing vehicle 2 included in the image captured by the imaging device 61.

Description

Technical Field

[0001] The present invention relates to a coupled vehicle in which a towed vehicle is towed by a towing vehicle.

Background Art

[0002] Conventionally, there is a coupled vehicle in which a towed vehicle and a towing vehicle are connected, and it is possible to detect a hitch angle, which is the angle of the towed vehicle with respect to the towing vehicle when the coupled vehicle is viewed from above.

[0003] The trailer angle detection system described in Patent Document 1 images a marker of a towed vehicle (trailer) with a camera installed on the towing vehicle, and detects the hitch angle based on the position of the marker in the captured image. As the marker, an edge portion or a sticker of the towed vehicle is used.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The towed vehicle has various shapes, such as, for example, a box-shaped camping car or a boat trailer carrying a boat. In the system described in Patent Document 1, when an edge portion having a shape suitable for use as a marker does not exist at a position where it can be imaged by the camera of the towing vehicle, a sticker as a marker must be attached to an appropriate position of the towed vehicle, which increases the burden on the user and may also affect the appearance of the towed vehicle.

[0006] Therefore, the present invention aims to provide a coupling vehicle capable of detecting the relative angle of a towed vehicle to a towing vehicle without providing a marker on the towed vehicle for detecting the relative angle with respect to the towing vehicle. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a coupling vehicle comprising: a towing vehicle; a towed vehicle; a towing-side coupling member provided on the towing vehicle; a towed-side coupling member provided on the towed vehicle and connected to the towing-side coupling member; an imaging device attached to the towed vehicle for imaging the towing vehicle; and a processing unit for calculating the relative angle of the towed vehicle with respect to the towing vehicle based on the positions of feature points of the towing vehicle included in the image captured by the imaging device. [Effects of the Invention]

[0008] According to the present invention, it is possible to detect the relative angle of a towed vehicle with respect to a towing vehicle without providing the towed vehicle with a marker for detecting the relative angle with respect to the towing vehicle. [Brief explanation of the drawing]

[0009] [Figure 1] (a) to (c) are schematic diagrams showing coupled vehicles that are the target of relative angle detection according to embodiments of the present invention. [Figure 2] (a) is a structural diagram showing an example of the structure of the towing-side connecting member and the towed-side connecting member. (b) is a cross-sectional view of the towing-side connecting member and the towed-side connecting member in a combined state. [Figure 3] This is a block diagram showing the functional configuration of a relative angle detection device. [Figure 4] This is an explanatory diagram showing an example of the rear end of a towing vehicle as captured by an imaging device. [Figure 5] This is an explanatory diagram showing the front end of the towed vehicle. [Figure 6]The diagrams show coupled vehicles in a straight-line driving position; (a) is an explanatory diagram viewed from above in the vertical direction, and (b) is an explanatory diagram viewed from the left side of the towing vehicle and the towed vehicle. [Figure 7] This is a schematic diagram showing the positional relationship between the towed vehicle, the towed vehicle, and the imaging device when the towed vehicle is tilted horizontally to the left relative to the towing vehicle, resulting in a hitch angle. [Figure 8] This is a schematic diagram showing the positional relationship between the towed vehicle, the towed vehicle, and the imaging device when the towed vehicle is tilted upward relative to the towing vehicle, resulting in a relative pitch angle. [Figure 9] This is an explanatory diagram showing the rear end of a towing vehicle as seen from the perspective of the towed vehicle, in a state where the towed vehicle is rolling relative to the towing vehicle. [Figure 10] This flowchart shows an example of the processing steps that a processing unit performs to calculate the hitch angle, relative pitch angle, and relative roll angle. [Modes for carrying out the invention]

[0010] [Embodiment] Embodiments of the present invention will be described with reference to the drawings. The embodiments described below are shown as preferred specific examples for carrying out the present invention, and some parts specifically illustrate various technically preferable technical matters, but the technical scope of the present invention is not limited to these specific embodiments.

[0011] Figures 1(a) to (c) are schematic diagrams showing a coupled vehicle 1 equipped with a relative angle detection device according to an embodiment of the present invention. Figure 1(a) shows the coupled vehicle 1 viewed from above, and Figure 1(b) shows the left side view of the coupled vehicle 1 in the forward direction. Figure 1(c) shows the coupled vehicle 1 viewed from the rear. In Figures 1(a) and (b), the centerline 2a of the towing vehicle 2 along the longitudinal direction of the towing vehicle 2 and the centerline 3a of the towed vehicle 3 along the longitudinal direction of the towed vehicle 3 are shown by dashed lines.

[0012] The coupled vehicle 1 comprises a towing vehicle 2 and a towed vehicle 3, with the towing vehicle 2 and the towed vehicle 3 connected by a towing-side coupling member 4 and a towed-side coupling member 5. Figures 1(a) to (c) illustrate the case where the towed vehicle 3 is a box-shaped camper van, but the towed vehicle is not limited to this, and may be, for example, a boat trailer carrying a boat. Furthermore, the towing vehicle 2 may be a manually operated vehicle in which the driver performs driving operations such as steering, or it may be an automated vehicle in which some or all of the driving operations are performed automatically.

[0013] Figure 2(a) is a structural diagram showing an example of the structure of the towing-side connecting member 4 and the towed-side connecting member 5. Figure 2(b) is a cross-sectional view of the towing-side connecting member 4 and the towed-side connecting member 5 in a combined state.

[0014] The towing-side connecting member 4 includes a hitch cross member 41 positioned along the width direction of the towing vehicle 2, a pair of hitch side members 42 fixed to both ends of the hitch cross member 41, a ball mount 43 projecting toward the rear of the towing vehicle 2 from the center of the hitch cross member 41 in the width direction, a hitch pin 44 projecting upward from the ball mount 43, and a spherical hitch ball 45 integrally provided with the upper end of the hitch pin 44. The hitch cross member 41 and the pair of hitch side members 42 are positioned inside the rear bumper 20 of the towing vehicle 2. The ball mount 43, hitch pin 44, and hitch ball 45 are exposed to the rear from the rear bumper 20. The pair of hitch side members 42 are fixed to the body of the towing vehicle 2 by a plurality of bolts.

[0015] The towed-side connecting member 5 includes a coupler 51 that covers the hitch ball 45, a latch mechanism 52 for preventing the coupler 51 from coming off the hitch ball 45, a rod-shaped tongue 53 to which the coupler 51 is fixed at the tip, and a pair of side beams 54 that extend in a direction inclined with respect to the longitudinal direction of the tongue 53. One end of each side beam 54 is connected to the tongue 53. The base end of the tongue 53 and the other end of each of the pair of side beams 54 are connected to the chassis of the towed vehicle 3.

[0016] As shown in Fig. 2(b), the coupler 51 has a cup portion 511 for accommodating the hitch ball 45. The latch mechanism 52 includes a lever support 520, a lever 521 that is pivotally operated with respect to the lever support 520, a latch plate 522 that faces the upper surface 51a of the coupler 51, a latch bar 523 that enters between the upper surface 51a of the coupler 51 and the latch plate 522 when the lever 521 is operated, a lock plate 524 that receives the hitch ball 45 from below, a coil spring 525 that biases the lock plate 524 downward, and bolts 526 and nuts 527 that connect the latch plate 522 and the lock plate 524.

[0017] The lock plate 524 is rotatable about a support pin 512 provided on the coupler 51. When the lever 521 is operated as shown by the arrow A in Fig. 2(b), the latch plate 522 is lifted upward with respect to the coupler 51 by the latch bar 523, and the lock plate 524 prevents the hitch ball 45 from coming out. The inner surface 511a of the cup portion 511 in the coupler 51 is a concave spherical surface with a curvature corresponding to the curvature of the surface 45a of the hitch ball 45. The coupler 51 can swing in all directions about the center point of the hitch ball 45 by the sliding between the inner surface 511a of the cup portion 511 and the surface 45a of the hitch ball 45. Hereinafter, this center point of the hitch ball 45 is referred to as the hitch point 450.

[0018] In the articulated vehicle 1, the relative angle of the towed vehicle 3 with respect to the towing vehicle 2 varies variously. Particularly, when the towed vehicle 3 is in reverse with the front side in the traveling direction, the relative angle of the towed vehicle 3 with respect to the towing vehicle 2 is an important index for driving operation. For this reason, a relative angle detection device 6 is used in the articulated vehicle 1. When the towing vehicle 2 is a manually operated vehicle (non-automatic driving vehicle), an image showing the detection result of the relative angle detection device 6 is displayed on a display arranged in the cab of the towing vehicle 2 to assist the driver's driving operation. Also, when the towing vehicle 2 is an automatic driving vehicle, the towing vehicle 2 is automatically steered based on the detection result of the relative angle detection device 6.

[0019] The relative angles of the towed vehicle 3 with respect to the towing vehicle 2 include the hitch angle, which indicates the horizontal tilt of the towed vehicle 3 relative to the towing vehicle 2; the relative pitch angle, which indicates the vertical tilt of the towed vehicle 3 relative to the towing vehicle 2; and the relative roll angle, which is the difference between the roll angle of the towing vehicle 2 and the roll angle of the towed vehicle 3. Figure 1(a) shows the hitch angle θh when the towed vehicle 3 is tilted to the left relative to the towing vehicle 2. Figure 1(b) shows the relative pitch angle θp when the towed vehicle 3 is tilted upward relative to the towing vehicle 2. Figure 1(c) shows the relative roll angle θr when the towed vehicle 3 is tilted clockwise relative to the towing vehicle 2, as viewed from the rear of the coupled vehicle 1.

[0020] The relative angle detection device 6 according to this embodiment can detect the hitch angle, relative pitch angle, and relative roll angle of the towed vehicle 3 with respect to the towing vehicle 2. Next, the configuration, arrangement, and operation of the relative angle detection device 6 will be described.

[0021] Figure 3 is a block diagram showing the functional configuration of the relative angle detection device 6. The relative angle detection device 6 is attached to the towed vehicle 3 and includes an imaging device 61 that images the towing vehicle 2, and a processing unit 62 that calculates the relative angle of the towed vehicle 3 with respect to the towing vehicle 2 based on the information obtained from the imaging device 61. The imaging device 61 images the towing vehicle 2 in response to a command from the processing unit 62 and sends the information of the captured image to the processing unit 62. The imaging device 61 and the processing unit 62 can communicate with each other, for example, by wireless signal.

[0022] As shown in Figure 2(a), the imaging device 61 is attached to the front end surface 3b of the towed vehicle 3. Hereinafter, the length L in the longitudinal direction of the towed vehicle 3 from the hitch point 450 to the imaging device 61 when the towing-side connecting member 4 and the towed-side connecting member 5 are connected is referred to as the reference imaging distance (see Figure 2(a)). In the example shown in Figure 2(a), the length of the towed-side connecting member 5 from the hitch point 450 to the towed vehicle 3 is the reference imaging distance.

[0023] The arithmetic processing unit 62 includes a reference shooting distance storage unit 621 that stores information on the reference shooting distance, a positional relationship information storage unit 622 that stores positional relationship information indicating the relative positional relationship between the feature points of the towed vehicle 2 captured by the imaging device 61 and the hitch point 450, and an imaging device position information storage unit 623 that stores information on the mounting position of the imaging device 61 on the towed vehicle 3. The arithmetic processing unit 62 can also acquire information regarding the driving state of the towed vehicle 2, such as vehicle speed and yaw rate, via a communication network such as CAN (Controller Area Network). Based on this information, the arithmetic processing unit 62 detects the relative angle of the towed vehicle 3 with respect to the towed vehicle 2.

[0024] The relative angle detection result from the processing unit 62 is sent, for example, to the display device 7 of the towing vehicle 2, and an image showing the detection result from the relative angle detection device 6 is displayed on the in-cabin touch panel display 71, as shown in Figure 3. Figure 3 shows an example display in which an overhead image 710 is displayed in the first display area 71a of the touch panel display 71, showing a graphic symbol 711 representing the towing vehicle 2 and a graphic symbol 712 representing the towed vehicle 3, tilted according to the hitch angle detected by the relative angle detection device 6. In the second display area 71b of the touch panel display 71, an image captured by, for example, the imaging device 61 is displayed.

[0025] The driver performs steering operations by referring to the information displayed on the touch panel display 71. The touch panel display 71 may also display an image showing the recommended steering wheel rotation direction according to the hitch angle detected by the relative angle detection device 6. Furthermore, if the towing vehicle 2 is an autonomous vehicle, the detection result of the relative angle detection device 6 is output to the autonomous driving device 8.

[0026] Information on the reference shooting distance is input, for example, by the users of the towing vehicle 2 and the towed vehicle 3, and stored in the reference shooting distance storage unit 621 of the arithmetic processing unit 62. This input can be done, for example, via the touch panel display 71. If a user owns multiple towed vehicles 3 (for example, a camper van, boat trailer, jet ski trailer, etc.), the user can set the reference shooting distance when switching towed vehicles 3, allowing the relative angle detection device 6 to appropriately detect the hitch angle and relative pitch angle.

[0027] Figure 4 is an explanatory diagram showing an example of the rear end of the towing vehicle 2 as captured by the imaging device 61. The rear end of the towing vehicle 2 is equipped with a pair of lights 21 and 22, a logo mark 23, and a license plate 24. The left and right rear wheels 25 and 26 are also subjects of imaging by the imaging device 61. These lights 21 and 22, the logo mark 23, the license plate 24, and the rear wheels 25 and 26 are not only unique structures of the towing vehicle 2, but also characteristic features of the towing vehicle 2 included in the image captured by the imaging device 61. The lights 21 and 22 are rear combination lamps having brake lights, turn signals, tail lights, and reverse lights. Note that the structures of the towing vehicle 2 are those that have been installed on the towing vehicle 2 since its manufacture and are inherent in the body structure of the towing vehicle 2 of that particular model.

[0028] Here, as shown in Figure 4, an XYZ Cartesian coordinate system is defined with the hitch point 450 as the origin of each coordinate axis. The X axis is the coordinate axis in the width direction of the towing vehicle 2, and the Y axis is the coordinate axis in the vertical direction of the towing vehicle 2. The Z axis is the coordinate axis in the front-rear direction of the towing vehicle 2. The positional relationship information storage unit 622 of the arithmetic processing unit 62 stores the X, Y, and Z coordinates of the characteristic points of the towing vehicle 2, namely the lights 21, 22, the logo mark 23, the license plate 24, and the rear wheels 25, 26. These coordinate values ​​are input to the arithmetic processing unit 62 by the operator when the towing-side coupling member 4 is attached to the towing vehicle 2, and stored in the positional relationship information storage unit 622. The coordinate values ​​of each characteristic point may be measured by the operator, for example, but they may also be provided to the operator on paper or electronic storage media that records the coordinate values ​​of the characteristic points for each applicable vehicle type attached to the towing-side coupling member 4.

[0029] The imaging device 61 is installed, for example, by the user of the towed vehicle 3. In this case, the imaging device 61 is not necessarily installed at the center of the width direction of the towed vehicle 3, but may be installed offset to the right or left from the center of the width direction of the towed vehicle 3. In this embodiment, the arithmetic processing unit 62 calculates the installation position of the imaging device 61 based on the information obtained from the imaging device 61 when the coupled vehicle 1 is traveling in a straight line. The arithmetic processing unit 62 detects the relative angle of the towed vehicle 3 with respect to the towing vehicle 2, taking into account the calculated installation position of the imaging device 61. The specific processing contents of the arithmetic processing unit 62 will be described in detail below.

[0030] Figure 5 is an explanatory diagram showing the front end surface 3b of the towed vehicle 3 together with the towed-side connecting member 5 and the hitch point 450. In Figure 5, the horizontal offset amount of the mounting position of the imaging device 61 relative to the hitch point 450 is shown as Oh, and the vertical offset amount of the mounting position of the imaging device 61 relative to the hitch point 450 is shown as Ov. Here, the mounting position of the imaging device 61 specifically refers to the center position of the lens 611 of the imaging device 61.

[0031] Figure 6(a) is an explanatory diagram showing the coupled vehicle 1 in a straight-line travel state viewed from vertically above. Figure 6(b) is an explanatory diagram showing the coupled vehicle 1 in a straight-line travel state viewed from the left side of the towing vehicle 2 and the towed vehicle 3. In a straight-line travel state, the towing vehicle 2 and the towed vehicle 3 are aligned in a straight line with respect to the direction of travel, and the hitch angle, relative pitch angle, and relative roll angle are substantially zero.

[0032] The processing unit 62 can detect the distance between the imaging device 61 and the feature points of the towing vehicle 2 based on the information obtained from the imaging device 61. This distance can be detected, for example, by analyzing the images of each feature point when the focus (focal length) of the imaging device 61 is changed.

[0033] The horizontal offset amount Oh of the imaging device 61 can be determined, for example, by the distances D1 and D2 between the left and right pair of lamps 21 and 22 and the imaging device 61. When the offset amount Oh is zero, distances D1 and D2 are equal, and the difference between distances D1 and D2 increases as the offset amount Oh increases. Furthermore, the arithmetic processing unit 62 can calculate the distance D3 between the left and right pair of lamps 21 and 22 from the information stored in the positional relationship information storage unit 622, and can calculate the offset amount Oh based on the principle of trigonometric functions from the relationship between distances D1, D2, and D3.

[0034] Furthermore, the vertical offset amount Ov of the imaging device 61 can be determined by the distances between the imaging device 61 and multiple feature points that are located at different vertical positions. For example, if the distances D4 and D5 between the imaging device 61 and the left-side lamp 21 and license plate 24 are known, the distance D6 between the lamp 21 and the license plate 24 can be calculated from the information stored in the positional relationship information storage unit 622, and the offset amount Ov can be calculated based on the principle of trigonometric functions, as described above.

[0035] Figure 7 is a schematic diagram showing the positional relationship between the towed vehicle 2, the towed vehicle 3, and the imaging device 61 when the towed vehicle 3 is tilted horizontally to the left relative to the towing vehicle 2, resulting in a hitch angle θh. In Figure 7, θ1 is the angle between the straight line connecting the hitch point 450 and the left-side light fixture 21 and the centerline 2a of the towing vehicle 2, and can be calculated from the information stored in the positional relationship information storage unit 622. θ2 is the angle between the straight line connecting the hitch point 450 and the imaging device 61 and the centerline 3a of the towed vehicle 3, and can be calculated from the reference shooting distance L and the horizontal offset amount Oh.

[0036] θ3 is the angle formed by the line connecting the hitch point 450 and the left-side light fixture 21, and the line connecting the hitch point 450 and the imaging device 61. This angle can be determined by the lengths of the sides of triangle T1, which has hitch point 450, the left-side light fixture 21, and the imaging device 61 as its vertices. In Figure 7, the distance between hitch point 450 and the imaging device 61 is determined by the square root of the sum of the squares of the reference shooting distance L and the offset amount Oh. The distance between hitch point 450 and the left-side light fixture 21 can be calculated from the information stored in the positional relationship information storage unit 622. The distance between the imaging device 61 and the left-side light fixture 21 can be determined by analyzing the image captured by the imaging device 61. The hitch angle θh can be determined from θ1, θ2, and θ3 using the formula 180(°)-θ1-θ2-θ3, as shown in Figure 7.

[0037] Figure 8 is a schematic diagram showing the positional relationship between the towed vehicle 2, the towed vehicle 3, and the imaging device 61 when the towed vehicle 3 is tilted upward relative to the towing vehicle 2, resulting in a relative pitch angle θp. In Figure 8, θ4 is the angle formed by the straight line connecting the hitch point 450 and the left-side light fixture 21, and the straight line passing through the hitch point 450 and parallel to the front-rear direction of the towing vehicle 2, and can be calculated from the information stored in the positional relationship information storage unit 622. θ5 is the angle formed by the straight line connecting the hitch point 450 and the imaging device 61, and the straight line passing through the hitch point 450 and parallel to the front-rear direction of the towed vehicle 3, and can be calculated from the reference shooting distance L and the vertical offset amount Ov.

[0038] θ6 is the angle formed by the line connecting the hitch point 450 and the left-side light fixture 21, and the line connecting the hitch point 450 and the imaging device 61. This angle can be determined by the lengths of the sides of triangle T2, which has hitch point 450, the left-side light fixture 21, and the imaging device 61 as its vertices. In Figure 8, the distance between hitch point 450 and the imaging device 61 is determined by the square root of the sum of the squares of the reference shooting distance L and the offset amount Ov. The distance between hitch point 450 and the left-side light fixture 21 can be calculated from the information stored in the positional relationship information storage unit 622. The distance between the imaging device 61 and the left-side light fixture 21 can be determined by analyzing the image captured by the imaging device 61. The relative pitch angle θp can be determined from θ4, θ5, and θ6 using the formula 180(°)-θ4-θ5-θ6, as shown in Figure 7.

[0039] Figure 9 is an explanatory diagram showing the rear end of the towing vehicle 2 as seen from the side of the towed vehicle 3 when it is rolling relative to the towing vehicle 2. When the towed vehicle 3 rolls relative to the towing vehicle 2, for example, when the relative roll angle θr is zero, the straight line connecting the left and right lights 21 and 22 that extend horizontally is tilted with respect to the horizontal direction. The processing unit 62 can detect this tilt from the information of the image captured by the imaging device 61 and determine the relative roll angle.

[0040] Figure 10 is a flowchart showing an example of the processing procedure performed by the arithmetic processing unit 62 to calculate the hitch angle θh, relative pitch angle θp, and relative roll angle θr. It is assumed that the reference shooting distance storage unit 621 and the positional relationship information storage unit 622 of the arithmetic processing unit 62 already store reference shooting distance information and positional relationship information.

[0041] In the flowchart shown in Figure 10, the arithmetic processing unit 62 first determines whether the coupled vehicle 1 is traveling in a straight line (step S1). The fact that the coupled vehicle 1 is traveling in a straight line can be detected, for example, by the vehicle speed being above a predetermined value and the yaw rate being substantially zero. If the result of this determination is Yes, the arithmetic processing unit 62 detects the mounting position of the imaging device 61 based on the distance information between the imaging device 61 and the feature points of the towed vehicle 2 obtained from the imaging device 61 (step S2). Specifically, it calculates offset amounts Oh and Ov, which indicate the mounting position of the imaging device 61 on the towed vehicle 3.

[0042] Next, the processing unit 62 calculates the distance between the imaging device 61 and at least one feature point of the towing vehicle 2 (for example, the left-side light fixture 21) based on the information from the imaging device 61 (step S3), and calculates the hitch angle θh and relative pitch angle θp as described above (step S4). The processing unit 62 also calculates the relative roll angle θr based on the inclination of multiple feature points in the image captured by the imaging device 61 (for example, the positions of the left and right light fixtures 21 and 22) (step S5).

[0043] Subsequently, the arithmetic processing unit 62 determines whether or not to stop detecting the hitch angle θh, relative pitch angle θp, and relative roll angle θr (step S6). If the result of this determination is No, the processing in steps S3 to S5 is repeated. The arithmetic processing unit 62 determines to stop detecting the hitch angle θh, relative pitch angle θp, and relative roll angle θr, for example, when the vehicle speed of the towing vehicle 2 becomes zero or when the shift lever is shifted to the P (parking) range.

[0044] Furthermore, the process in step S2 only needs to be performed at least once when new information is stored or updated in the reference shooting distance storage unit 621 or the positional relationship information storage unit 622, or when the mounting position of the imaging device 61 is changed. After that, the hitch angle θh, relative pitch angle θp, and relative roll angle θr may be calculated using the stored offset amount Oh and offset amount Ov information.

[0045] Furthermore, in step S3, the distance between one of the multiple feature points of the towing vehicle 2 and the imaging device 61 may be calculated, and based on this calculation result, the hitch angle θh, relative pitch angle θp, and relative roll angle θr may be calculated in steps S4 and S5. Alternatively, the distance between the multiple feature points of the towing vehicle 2 and the imaging device 61 may be calculated, and the calculation results of the hitch angle θh, relative pitch angle θp, and relative roll angle θr obtained based on the calculation results of the distance to each feature point may be averaged to obtain the detection result. This makes it possible to improve the accuracy of the relative angle detection result of the relative angle detection device 6.

[0046] (Effects of the embodiment) According to the embodiment described above, the arithmetic processing unit 62 calculates the hitch angle θh, relative pitch angle θp, and relative roll angle θr based on information obtained from the imaging device 61 attached to the towed vehicle side 3 that images the towing vehicle 2. Therefore, the relative angle of the towed vehicle with respect to the towing vehicle can be detected without providing a marker on the towed vehicle 3 for detecting the relative angle with respect to the towing vehicle 2.

[0047] Furthermore, the processing unit 62 calculates the mounting position of the imaging device 61 on the towed vehicle 3 based on the information obtained from the imaging device 61 when the coupled vehicle 1 is traveling in a straight line, and detects the relative angle of the towed vehicle with respect to the towing vehicle by taking this mounting position into account. Therefore, the user does not need to store the mounting position of the imaging device 61 in the processing unit 62, and the hitch angle θh, relative pitch angle θp, and relative roll angle θr can be accurately determined while reducing the burden on the user.

[0048] (Note) The present invention has been described above based on embodiments, but these embodiments do not limit the invention as defined in the claims. It should also be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention. Furthermore, the present invention can be implemented by omitting some components, or by adding or substituting components, without departing from its spirit. [Explanation of Symbols]

[0049] 1...Two-car train set 2...Towing vehicle 21, 22…Lighting fixtures 23…Logo mark 24...License plate 25,26...Rear wheel 3...Towed vehicle 4...Towed coupling member 45...Hitchball 450...Hitch point 5...Towed side connecting member 51...Coupler 6…Relative angle detection device 61…Imaging device 62… Arithmetic Processing Unit

Claims

1. Towing vehicle and The towed vehicle and, A towing-side connecting member provided on the aforementioned towing vehicle, A towed-side connecting member provided on the towed vehicle and connected to the towing-side connecting member, An imaging device attached to the towed vehicle for imaging the towing vehicle, A processing unit that calculates the relative angle of the towed vehicle to the towing vehicle based on the position of the feature points of the towing vehicle included in the image captured by the imaging device, Equipped with, Articulated train cars.

2. The processing unit detects the relative angle by taking into account the mounting position of the imaging device based on information obtained from the imaging device when the coupled vehicle is traveling in a straight line. The articulated vehicle according to claim 1.

3. The processing unit calculates the mounting position of the imaging device based on the position of the feature points of the towing vehicle included in the image captured by the imaging device when the coupled vehicle is traveling in a straight line. The articulated vehicle according to claim 2.

4. The towing-side connecting member has a spherical hitch ball, The towed-side connecting member has a coupler that houses the hitch ball, The processing unit stores positional relationship information indicating the relative positional relationship between the hitch point, which is the center point of the hitch ball, and the feature point, and detects the relative angle based on the distance between the imaging device and the feature point and the positional relationship information. The articulated vehicle according to claim 3.

5. The aforementioned characteristic features are the structure of the towing vehicle, The articulated vehicle according to claim 3 or 4.

Images