Device and method for measuring vehicle swing amplitude

Abstract

The present invention relates to the technical field of automobile and trailer inspection and testing equipment, and specifically to a vehicle swing amplitude measuring device and method. The vehicle swing amplitude measuring device comprises a parallel light emitting mechanism, a dot laser emitter and a shooting mechanism. The parallel light emitting mechanism is used to be installed on the front axle of the vehicle to be tested, and can emit two parallel line beams along the central axis direction of the vehicle to be tested and irradiated on the ground below the rear axle of the vehicle to be tested; the dot laser emitter is used to be set at the center of the rear axle of the vehicle to be tested, and can emit light beams vertically toward the ground, forming a light spot on the ground located on the axial symmetry line of the two parallel line beams when the vehicle to be tested is parked in a straight driving state; the shooting mechanism is used to be set on the rear axle of the vehicle to be tested, and shoots images of the parallel line beams and light spots when the vehicle to be tested is driving. It can solve the problems of high cost of detection equipment, inconvenient installation and low detection accuracy in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of automobile and trailer detection and testing equipment, and in particular to a vehicle swing amplitude measurement device and method. Background Art

[0002] The reasons for vehicle swaying are: caused by the chassis system, wheel imbalance, loose suspension components, large steering gear clearance, etc., which will cause the vehicle to shake while driving. Unbalanced wheels: Because the quality of tires and steel rims cannot be guaranteed to be uniform during manufacturing, the wheels must be dynamically balanced after assembly. Loose suspension frame: The chassis suspension is composed of various connecting rods and support arms, and these connecting rods and support arms are connected to each other through ball heads and rubber bushings. Under normal circumstances, the connection between these components is very tight, but as the wear of the ball heads and bushings increases, the components will loosen, causing the suspension to loosen, and the vehicle body will shake when walking. Too much steering gear clearance: When the gear rack is used for a long time, it will wear and produce clearance between each other. Even if the steering wheel is not turned, the wheels will swing slightly left and right due to the unevenness of the road, causing the vehicle body to shake.

[0003] The swing amplitude of the trailer directly reflects the stability performance of the automobile train during dynamic operation. The national standard GB / T26778-2011 "Performance Requirements and Test Methods for Automobile Trains" and the industry standard JT / T 1178.2-2019 "Safety Technical Conditions for Operating Trucks Part 2 Towing Vehicles and Trailers" both stipulate that when the automobile train is running, the swing amplitude of the rear axle center of the trailer relative to the front axle center of the tractor should not exceed a certain limit.

[0004] At present, in the management of standard models of commercial vehicles in my country, relevant standards have been enforced. Since the relevant standards only clarify the physical meaning of the swing amplitude and the corresponding limit requirements, but do not specify specific test methods, and there is no special testing equipment in actual testing, the industry mainly uses two methods to test this project: one is to use a dual-axis optical speed detector, and the other is to use GPS plus positioning base station. The existing methods have the defects of high cost of testing equipment, inconvenient installation and low detection accuracy. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide a vehicle swing amplitude measurement device and method, which can solve the problems existing in the prior art of high cost of detection equipment, inconvenient installation and low detection accuracy.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] In one aspect, the present invention provides a vehicle swing amplitude measuring device, comprising:

[0008] A parallel light emitting mechanism, which is used to be installed on the front axle of the vehicle to be tested and can emit two parallel light beams along the central axis of the vehicle to be tested and illuminate the ground below the rear axle of the vehicle to be tested;

[0009] A dot laser emitter, which is used to be arranged at the center of the rear axle of the vehicle to be tested and can emit a light beam vertically toward the ground, forming a light spot on the ground that is located on the axis of symmetry of the two parallel beams when the vehicle to be tested is parked in a straight-line driving state;

[0010] The shooting mechanism is used to be arranged on the rear axle of the vehicle to be tested and to shoot images of parallel line bundles and light spots when the vehicle to be tested is traveling.

[0011] In some optional schemes, the two parallel line bundles are spaced apart by a set distance.

[0012] In some optional solutions, the set distance is twice the trailer swing limit.

[0013] In some optional solutions, the parallel light emitting mechanism is installed on the front axle of the vehicle to be tested via a first suction cup.

[0014] In some optional solutions, the dot laser emitter is mounted on the rear axle of the vehicle to be tested via a second suction cup.

[0015] In some optional schemes, the vehicle swing amplitude measuring device also includes a video display, which is connected to the camera signal and is used to display the image of the parallel line beam and the light spot when the measured vehicle is traveling.

[0016] In some optional solutions, the video display is installed in the cab and is connected to the shooting mechanism wirelessly.

[0017] On the other hand, the present invention provides a vehicle swing amplitude measurement method, which is implemented using any of the above-mentioned vehicle swing amplitude measurement devices, comprising the following steps:

[0018] Make the vehicle under test run according to the method specified in the standard, and take images of the parallel line beams and light spots when the vehicle is running;

[0019] According to the images of the parallel line beams and the light spots when the tested vehicle is running, it is judged whether the swing amplitude of the tested vehicle meets the requirements.

[0020] In some optional schemes, the interval between the two parallel wire bundles is set to be twice the trailer swing limit, and by observing whether the light spot exceeds the parallel wire bundles when the tested vehicle is traveling, it is determined whether the swing amplitude of the tested vehicle meets the requirements.

[0021] In some optional solutions, a video display connected to the camera signal is installed in the cab of the vehicle under test, and the video display displays the images of the parallel line beams and light spots when the vehicle under test is driving in real time.

[0022] Compared with the prior art, the advantages of the present invention are: during the driving of the tested vehicle, the light spot swings left and right relative to the two parallel beams on the ground. When the initial spacing of the two parallel beams emitted by the parallel light emitting mechanism is adjusted and fixed according to the swing amplitude limit specified in the standard, it is only necessary to record the movement of the light spot on the ground relative to the parallel beams during the driving of the tested vehicle through the shooting mechanism, and then visually determine whether the swing amplitude of the test sample vehicle meets the standard requirements through the video image. The dual-axis optical speed detector and GPS plus positioning base station method used in the prior art have the defects of high detection equipment cost, inconvenient installation and low detection accuracy; this solution only needs three laser emitters and one camera to complete the detection of the swing amplitude of the tested vehicle, and the detection result is basically not affected by other conditions, so the detection accuracy is high. This solution can save costs, is simple to install, and can also improve detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 Schematic diagram of the installation position of the vehicle swing amplitude measuring device in an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the positions of parallel line beams and light spots when the tested vehicle is traveling in an embodiment of the present invention;

[0026] In the figure: 1. Parallel light emitting mechanism; 2. Front axle; 3. Rear axle; 4. Dot laser emitter; 5. Shooting mechanism; 6. Parallel line beam; 7. Light spot; 8. Axis of symmetry. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0028] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0029] Figure 1 Schematic diagram of the installation position of the vehicle swing amplitude measuring device in an embodiment of the present invention; Figure 2 Schematic diagram of the positions of parallel line beams and light spots when the tested vehicle is traveling in an embodiment of the present invention; Figure 1 and Figure 2 As shown, the present invention provides a vehicle swing amplitude measuring device, comprising: a parallel light emitting mechanism 1, a dot laser emitter 4 and a photographing mechanism 5. The parallel light emitting mechanism 1 is used to be installed on the front axle 2 of the vehicle to be tested, and can emit two parallel line beams 6 along the central axis direction of the vehicle to be tested and irradiated on the ground below the rear axle 3 of the vehicle to be tested; the dot laser emitter 4 is used to be set at the center of the rear axle 3 of the vehicle to be tested, and can emit a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axis symmetry line of the two parallel line beams 6 when the vehicle to be tested is parked in a straight driving state; the photographing mechanism 5 is used to be set on the rear axle 3 of the vehicle to be tested, and shoot the image of the parallel line beams 6 and the light spot 7 when the vehicle to be tested is driving.

[0030] When using the vehicle swing amplitude measuring device, the vehicle to be tested is parked in a straight-line driving state, that is, the vehicle to be tested is parked in a straight-line driving state; the parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle to be tested, and the parallel light emitting mechanism 1 emits two parallel line beams 6 along the central axis direction of the vehicle to be tested and irradiated on the ground below the rear axle 3 of the vehicle to be tested; the dot laser emitter 4 is installed at the center of the rear axle 3 of the vehicle to be tested, and the light beam is vertically emitted toward the ground, forming a light spot 7 on the ground located on the axial symmetry line of the two parallel line beams 6, the axial symmetry line of the two parallel line beams 6, that is, the symmetry axis 8 of the two parallel line beams 6. The vehicle to be tested is driven according to the method specified in the standard, and the images of the parallel line beams 6 and the light spot 7 are taken when the vehicle is driving; according to the images of the parallel line beams 6 and the light spot 7 when the vehicle to be tested is driven, it is judged whether the swing amplitude of the vehicle to be tested meets the requirements. During the driving process of the tested vehicle, the light spot 7 swings left and right relative to the two parallel beams 6 on the ground. When the initial spacing between the two parallel beams 6 emitted by the parallel light emitting mechanism 1 is adjusted and fixed according to the swing amplitude limit specified in the standard, it is only necessary to record the movement of the light spot 7 on the ground relative to the parallel beams 6 during the driving process of the tested vehicle through the shooting mechanism 5, and then it can be visually determined through the video image whether the swing amplitude of the test sample vehicle meets the standard requirements. The dual-axis optical speed detector and GPS plus positioning base station method used in the prior art have the defects of high detection equipment cost, inconvenient installation and low detection accuracy; this solution only needs three laser emitters and one camera to complete the detection of the swing amplitude of the tested vehicle, and the detection result is basically not affected by other conditions, so the detection accuracy is high. This solution can save costs, is simple to install, and can also improve detection accuracy.

[0031] Since the required components are all ready-made and inexpensive, it can be realized by simply designing, processing, installing connectors and video processing software. The cost is less than 10% compared with the existing photoelectric speedometer and GPS+ positioning base station. The existing photoelectric speedometer and GPS+ positioning base station solution can only achieve centimeter-level measurement accuracy. In this solution, the parallel light emitting mechanism 1 uses two straight laser marking instruments. Since the marking width of the laser marking instrument can be set to within 1mm, and the image processing technology can also achieve a measurement error of less than 1mm for the distance between the circular light spot and the center line, the measurement accuracy of this method can reach the millimeter level. The parts used in this solution are small in size and light in weight, and can be easily installed in the middle of the axle using a magnetic suction cup. The test results can be displayed in real time on a display placed in the cab, which is intuitive and convenient.

[0032] In some optional embodiments, the two parallel line bundles 6 are spaced apart by a set distance.

[0033] In some optional embodiments, the set distance is twice the trailer swing limit.

[0034] In this embodiment, the spacing between the two parallel beams 6 is set to twice the trailer swing limit. In this setting, since the parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle to be tested, two parallel beams 6 are emitted along the central axis of the vehicle to be tested and illuminated on the ground below the rear axle 3 of the vehicle to be tested; the dot laser emitter 4 is set at the center of the rear axle 3 of the vehicle to be tested, and emits a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axis of symmetry of the two parallel beams 6 when the vehicle to be tested is parked in a straight-line driving state. It is only necessary to record the movement of the light spot 7 on the ground relative to the parallel beam 6 during the driving of the vehicle to be tested through the shooting mechanism 5, and it is possible to visually determine whether the swing amplitude of the test sample vehicle meets the standard requirements through video images.

[0035] In some other embodiments, the set distance between the two parallel line beams 6 can be determined by measuring the actual spacing between the two parallel line beams 6 on the ground, and then obtaining the image spacing between the parallel line beams 6 and the light spot 7 in the image. The actual distance between each pixel in the image and the light spot 7 on the ground can be obtained by measuring the actual spacing between the two parallel line beams 6 on the ground and the image spacing in the image. The actual distance between the parallel line beams 6 and the light spot 7 on the ground can be obtained by obtaining the image of the parallel line beams 6 and the light spot 7 when the vehicle is traveling, thereby determining whether the swing amplitude of the measured vehicle meets the requirements.

[0036] In some optional embodiments, the parallel light emitting mechanism 1 is mounted on the front axle 2 of the vehicle to be tested via a first suction cup.

[0037] The parallel light emitting mechanism 1 is provided with two straight line laser markers, which emit two parallel line beams 6 along the central axis of the vehicle to be tested and illuminate the ground below the rear axle 3 of the vehicle to be tested. The parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle to be tested through a first suction cup, which can facilitate the disassembly of the parallel light emitting mechanism 1 and the adjustment of the position, so that the two straight line laser markers can emit parallel line beams 6 along the central axis of the vehicle to be tested and illuminate the ground below the rear axle 3 of the vehicle to be tested.

[0038] In some optional embodiments, the dot laser emitter 4 is mounted on the rear axle 3 of the vehicle to be tested via a second suction cup.

[0039] In this embodiment, the dot laser emitter 4 is installed on the rear axle 3 of the vehicle to be tested through a second suction cup, which can facilitate the disassembly of the dot laser emitter 4 and the adjustment of the position so that the dot laser emitter 4 emits a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axial symmetry line of the two parallel beams 6.

[0040] In some optional embodiments, the vehicle swing amplitude measuring device further includes a video display, which is signal-connected to the photographing mechanism 5 and is used to display images of the parallel line beams 6 and light spots 7 when the measured vehicle is traveling.

[0041] In this embodiment, the image of the parallel line beam 6 and the light spot 7 when the vehicle under test is running is directly displayed on the video display through the video display. Since the parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle under test, two parallel line beams 6 along the central axis of the vehicle under test are emitted and irradiated on the ground below the rear axle 3 of the vehicle under test; the dot laser emitter 4 is arranged at the center of the rear axle 3 of the vehicle under test, and emits a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axis symmetry line of the two parallel line beams 6 when the vehicle under test is parked in a straight driving state. It is only necessary to record the movement of the light spot 7 on the ground relative to the parallel line beam 6 during the driving of the vehicle under test by the video display, and it is possible to visually determine whether the swing amplitude of the test sample vehicle meets the standard requirements through the video image. When the vehicle is driving, when the light spot 7 is located between the two parallel line beams 6, it can be determined that the swing amplitude of the vehicle under test meets the standard requirements. When the light spot 7 is located outside the two parallel line beams 6, it is determined that the swing amplitude of the vehicle under test does not meet the standard requirements.

[0042] In some optional embodiments, the video display is installed in the cab and is connected to the shooting mechanism 5 in a wireless manner.

[0043] In this embodiment, the video display is installed in the cab, which can facilitate the driver to see the swing amplitude of the tested vehicle in real time when driving the tested vehicle, and can record the relevant driving conditions based on the real-time images. The video display is connected to the shooting mechanism 5 in a wireless manner, which can simplify the modification of the tested vehicle and avoid the problem of troublesome wiring.

[0044] In addition, in the present scheme, the actual spacing between the two parallel line beams 6 on the ground can be measured according to the set distance set between the two parallel line beams 6, and then the image spacing between the parallel line beams 6 and the light spot 7 in the image can be obtained. The actual distance between each pixel in the image and the ground can be obtained by the actual spacing between the two parallel line beams 6 on the ground and the image spacing in the image. The actual distance between the parallel line beams 6 and the light spot 7 on the ground can be obtained by obtaining the images of the parallel line beams 6 and the light spot 7 when the vehicle is traveling, thereby obtaining the swing amplitude value of the measured vehicle, which is convenient for providing a more supportive basis for subsequent improvements.

[0045] On the other hand, the present invention provides a vehicle swing amplitude measurement method, which is implemented using the above-mentioned vehicle swing amplitude measurement device and includes the following steps:

[0046] S1: Make the vehicle under test run according to the method specified in the standard, and take images of the parallel line beam 6 and the light spot 7 when the vehicle is running.

[0047] In this example, the vehicle to be tested is parked in a straight-line driving state; the parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle to be tested, and the parallel light emitting mechanism 1 emits two parallel line beams 6 along the central axis of the vehicle to be tested and irradiated on the ground below the rear axle 3 of the vehicle to be tested; the dot laser emitter 4 is installed at the center of the rear axle 3 of the vehicle to be tested, and emits a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axial symmetry line of the two parallel line beams 6.

[0048] The vehicle under test is driven according to the method specified in the standard, and the image of the parallel line beam 6 and the light spot 7 when the vehicle is driving is captured by the shooting mechanism 5 .

[0049] S2: judging whether the swing amplitude of the tested vehicle meets the requirements according to the images of the parallel line beam 6 and the light spot 7 when the tested vehicle is running.

[0050] In some optional embodiments, the two parallel wire bundles 6 are set at a distance twice the trailer swing limit, and by observing whether the light spot 7 exceeds the parallel wire bundles 6 when the tested vehicle is traveling, it is determined whether the swing amplitude of the tested vehicle meets the requirements.

[0051] In this example, the interval between the two parallel wire beams 6 is set to be twice the limit of the trailer's swing amount. It is only necessary to use the video display to record the movement of the light spot 7 on the ground relative to the parallel wire beam 6 during the driving of the tested vehicle by the shooting mechanism 5, so as to visually determine whether the swing amplitude of the test sample vehicle meets the standard requirements through the video image. When the vehicle is driving, if the light spot 7 is located between the two parallel wire beams 6, it can be determined that the swing amplitude of the tested vehicle meets the standard requirements. When the light spot 7 is located outside the two parallel wire beams 6, it is determined that the swing amplitude of the tested vehicle does not meet the standard requirements.

[0052] In some optional embodiments, a video display connected to the signal of the shooting mechanism 5 is installed in the cab of the tested vehicle, and the image of the parallel line beam 6 and the light spot 7 when the tested vehicle is driving is displayed in real time through the video display.

[0053] In this embodiment, the video display is installed in the cab, so that the driver can see the swing amplitude of the tested vehicle in real time while driving the tested vehicle, and can directly judge whether the swing amplitude meets the requirements based on the real-time image.

[0054] In summary, the vehicle to be tested is parked in a straight-line driving state; the parallel light emitting mechanism 1 is installed on the front axle 2 of the vehicle to be tested, and the parallel light emitting mechanism 1 emits two parallel beams 6 along the central axis of the vehicle to be tested and irradiates the ground below the rear axle 3 of the vehicle to be tested; the dot laser emitter 4 is installed at the center of the rear axle 3 of the vehicle to be tested, and emits a light beam vertically toward the ground, forming a light spot 7 on the ground located on the axis of the two parallel beams 6. The vehicle to be tested is driven according to the method specified in the standard, and the images of the parallel beams 6 and the light spots 7 are taken when the vehicle is driving; according to the images of the parallel beams 6 and the light spots 7 when the vehicle to be tested is driven, it is judged whether the swing amplitude of the vehicle to be tested meets the requirements. During the driving process of the tested vehicle, the light spot 7 swings left and right relative to the two parallel beams 6 on the ground. When the initial spacing between the two parallel beams 6 emitted by the parallel light emitting mechanism 1 is adjusted and fixed according to the swing amplitude limit specified in the standard, it is only necessary to record the movement of the light spot 7 on the ground relative to the parallel beams 6 during the driving process of the tested vehicle through the shooting mechanism 5, and then it can be visually determined through the video image whether the swing amplitude of the test sample vehicle meets the standard requirements. The dual-axis optical speed detector and GPS plus positioning base station method used in the prior art have the defects of high detection equipment cost, inconvenient installation and low detection accuracy; this solution only needs three laser emitters and one camera to complete the detection of the swing amplitude of the tested vehicle, and the detection result is basically not affected by other conditions, so the detection accuracy is high. This solution can save costs, is simple to install, and can also improve detection accuracy.

[0055] Since the required components are all ready-made and inexpensive, it can be realized by simply designing, processing, installing connectors and video processing software. The cost is less than 10% compared with the existing photoelectric speedometer and GPS+ positioning base station. The existing photoelectric speedometer and GPS+ positioning base station solution can only achieve centimeter-level measurement accuracy. In this solution, the parallel light emitting mechanism 1 uses two straight laser marking instruments. Since the marking width of the laser marking instrument can be set to within 1mm, and the image processing technology can also achieve a measurement error of less than 1mm for the distance between the circular light spot and the center line, the measurement accuracy of this method can reach the millimeter level. The parts used in this solution are small in size and light in weight, and can be easily installed in the middle of the axle using a magnetic suction cup. The test results can be displayed in real time on a display placed in the cab, which is intuitive and convenient.

[0056] In addition, the interval between the two parallel wire beams 6 is set to be twice the limit of the trailer's swing amount. It is only necessary to use the video display to record the movement of the light spot 7 on the ground relative to the parallel wire beam 6 during the driving of the tested vehicle by the shooting mechanism 5, so that it can be visually determined through the video image whether the swing amplitude of the test sample vehicle meets the standard requirements. When the vehicle is driving, if the light spot 7 is located between the two parallel wire beams 6, it can be determined that the swing amplitude of the tested vehicle meets the standard requirements. When the light spot 7 is located outside the two parallel wire beams 6, it is determined that the swing amplitude of the tested vehicle does not meet the standard requirements.

[0057] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0058] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0059] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A vehicle swing amplitude measuring device, characterized in that: include: A parallel light emitting mechanism (1) is used to be installed on a front axle (2) of a vehicle to be tested and can emit two parallel line beams (6) along the central axis of the vehicle to be tested and irradiated on the ground below the rear axle (3) of the vehicle to be tested; A dot laser emitter (4) is used to be arranged at the center of the rear axle (3) of the vehicle to be tested and can emit a light beam vertically toward the ground to form a light spot (7) on the ground that is located on the axial symmetry line of the two parallel line beams (6) when the vehicle to be tested is parked in a straight-line driving state; The photographing mechanism (5) is used to be arranged on the rear axle (3) of the vehicle to be tested and to photograph images of the parallel line beam (6) and the light spot (7) when the vehicle to be tested is traveling.

2. The vehicle swing amplitude measuring device according to claim 1, characterized in that: The two parallel wire bundles (6) are arranged at a set distance.

3. The vehicle swing amplitude measuring device according to claim 2, characterized in that: The set distance is twice the trailer swing limit.

4. The vehicle swing amplitude measuring device according to claim 1, characterized in that: The parallel light emitting mechanism (1) is mounted on the front axle (2) of the vehicle to be tested via a first suction cup.

5. The vehicle swing amplitude measuring device according to claim 1, characterized in that: The dot laser emitter (4) is mounted on the rear axle (3) of the vehicle to be tested via a second suction cup.

6. The vehicle swing amplitude measuring device according to claim 1, characterized in that: It also includes a video display, which is connected to the shooting mechanism (5) by signal and is used to display images of the parallel line bundle (6) and the light spot (7) when the tested vehicle is traveling.

7. The vehicle swing amplitude measuring device according to claim 6, characterized in that: The video display is used to be installed in the cab and is connected to the shooting mechanism (5) in a wireless manner.

8. A method for measuring vehicle swing amplitude, characterized in that: The method is implemented by using the vehicle swing amplitude measuring device according to any one of claims 1 to 7, comprising the following steps: The vehicle under test is driven according to the method specified in the standard, and images of the parallel line bundle (6) and the light spot (7) are photographed when the vehicle is driving; According to the images of the parallel line bundle (6) and the light spot (7) when the tested vehicle is running, it is judged whether the swing amplitude of the tested vehicle meets the requirements.

9. The vehicle swing amplitude measurement method according to claim 8, characterized in that: The interval between the two parallel wire bundles (6) is set to be twice the trailer swing limit value, and by observing whether the light point (7) exceeds the parallel wire bundles (6) when the vehicle under test is running, it is judged whether the swing amplitude of the vehicle under test meets the requirements.

10. The vehicle swing amplitude measurement method according to claim 8, characterized in that: A video display connected to the signal of the shooting mechanism (5) is installed in the driving cab of the tested vehicle, and the images of the parallel wire bundle (6) and the light spot (7) when the tested vehicle is running are displayed in real time through the video display.

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