Detection Method and Detection Device for Abnormal Weighing Behavior

Abstract

The present application discloses a method for detecting abnormal weighing behaviors. The detection method includes: obtaining detection signals of a plurality of weighing sensors in a detection device; wherein, the detection device includes a horizontally arranged carrier and a plurality of weighing sensors that are arranged at intervals under the carrier, and the weighing sensors generate detection signals in response to the pressure of a weighed object on the carrier; determining trajectory information of the weighed object on the carrier according to the detection signals; and determining whether the weighed object has abnormal movement according to the trajectory information. The present application also discloses a detection device for abnormal weighing behaviors. By the above method, the present application can detect various abnormal driving behaviors, with high accuracy and good stability.

Description

Technical Field

[0001] This application relates to the field of motion detection, and particularly to a method and device for detecting abnormal weighing behaviors. Background Art

[0002] In the field of dynamic vehicles, there are various weighing schemes according to different weighing sensors. For example, there is narrow-strip weighing using quartz sensors, and flat-plate weighing using resistive strain weighing, etc. However, in the usage scenarios of these weighing schemes, there are still some drivers who will adopt some specific driving methods to reduce the weighing result of their own vehicles, such as squat weighing, jump weighing, straddle weighing, reversing, etc. We collectively refer to these driving behaviors as abnormal driving behaviors.

[0003] How to identify such abnormal driving behaviors, correct the vehicle weighing result, and ensure the accuracy of vehicle weighing is a problem that should be considered currently. Summary of the Invention

[0004] The main purpose of this application is to provide a method and device for detecting abnormal weighing behaviors, which can solve the problem in the prior art that various abnormal driving behaviors cannot be accurately identified.

[0005] To solve the above technical problem, the first technical solution adopted by this application is: to provide a method for detecting abnormal weighing behaviors, the detection method includes: obtaining detection signals of a plurality of weighing sensors in a detection device; wherein, the detection device includes a horizontally arranged carrier and a plurality of weighing sensors arranged at intervals under the carrier, and the weighing sensors generate detection signals in response to the pressure of the weighing object on the carrier; determining the trajectory information of the weighing object on the carrier according to the detection signals; and determining whether the weighing object has abnormal movement according to the trajectory information.

[0006] To solve the above technical problem, the second technical solution adopted by this application is: to provide a device for detecting abnormal weighing behaviors, the device includes: a carrier, which is horizontally arranged; a plurality of weighing sensors arranged at intervals, and the plurality of weighing sensors are respectively arranged under the carrier, and the weighing sensors are used to generate detection signals in response to the pressure of the weighing object on the carrier; a control device, connected to the plurality of weighing sensors, for obtaining detection signals, and for executing the detection method in the first technical solution to determine whether the weighing object on the carrier has abnormal movement.

[0007] The beneficial effect of this application is: by arranging weighing sensors under a horizontal carrier, obtaining the detection signals generated by the weighing sensors in response to the pressure of the weighing object, determining the position information of the object according to the detection signals, and then combining the time information to obtain the trajectory information of the weighing object, so as to judge whether the movement behavior of the weighing object is abnormal, with high accuracy and good stability. Description of the Drawings

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0009] Figure 1 It is a schematic flowchart of the first embodiment of the detection method for abnormal weighing behavior in this application;

[0010] Figure 2 It is a schematic flowchart of the second embodiment of the detection method for abnormal weighing behavior in this application;

[0011] Figure 3 It is a schematic flowchart of the third embodiment of the detection method for abnormal weighing behavior in this application;

[0012] Figure 4 It is a schematic flowchart of the fourth embodiment of the detection method for abnormal weighing behavior in this application;

[0013] Figure 5 It is a schematic structural diagram of the carrier of the detection device in an embodiment of the detection method for abnormal weighing behavior in this application;

[0014] Figure 6 It is a schematic flowchart of the fifth embodiment of the detection method for abnormal weighing behavior in this application;

[0015] Figure 7 It is a schematic structural diagram of the first embodiment of the detection device for abnormal weighing behavior in this application;

[0016] Figure 8 It is a schematic structural diagram of the second embodiment of the detection device for abnormal weighing behavior in this application. Detailed implementation manners

[0017] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0018] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0019] Reference to "embodiment" in this context means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0020] In the prior art, for how to identify abnormal driving behaviors of a vehicle during weighing, laser scanning sensors are usually arranged on both sides of the weighing unit. The driving behavior of the vehicle is determined based on the data detected by the laser sensors to check for abnormal driving behaviors such as squat weighing and reversing. However, this sensor identification method has high requirements for the external environment, poor sensitivity, and is easily affected by external interference factors resulting in incorrect judgments. Therefore, this application proposes a detection method and a detection device for weighing abnormal behaviors.

[0021] As Figure 1 shown, Figure 1 is a schematic flowchart of the first embodiment of the detection method for weighing abnormal behaviors in this application. The detection method includes the following steps:

[0022] S11: Obtain the detection signals of multiple weighing sensors in the detection device.

[0023] Among them, the detection device includes a horizontally arranged carrier and multiple weighing sensors spaced apart from each other under the carrier. The weighing sensor can generate a detection signal in response to the pressure of the weighed object on the carrier. The detection signal is related to the pressure intensity of the object.

[0024] Optionally, the sensor is a resistance strain sensor. Its working principle is that when subjected to pressure, the resistance on the bridge arm of the sensor bridge will change. After this change is filtered and amplified by the hardware circuit, a voltage signal proportional to the pressure it bears is formed.

[0025] S12: Determine the trajectory information of the weighed object on the carrier according to the detection signals.

[0026] According to the characteristic that the detection signal output by the load cell is related to the magnitude of the applied pressure, the detection signals output by multiple load cells can be calculated in multiple dimensions, so as to obtain the specific position of the weighed object on the carrier, and then the information about the movement trajectory of the object can be determined according to the movement time.

[0027] S13: Determine whether the weighed object has abnormal movement according to the trajectory information.

[0028] After obtaining the movement trajectory information of the object, according to one or more of the position information, time information, speed information, and acceleration information included in the trajectory information, determine whether the trajectory information belongs to the trajectory of abnormal driving behavior. If so, subsequent algorithm compensation can be performed on the relevant weighing unit.

[0029] In summary, in this embodiment, by setting load cells under the horizontal carrier, obtaining the detection signals generated by the load cells in response to the pressure of the weighed object, determining the position information of the object according to the detection signals, and then combining the time information to obtain the trajectory information of the weighed object, so as to determine whether the movement behavior of the weighed object is abnormal, which is less affected by external interference factors, has high accuracy, and good stability.

[0030] Regarding how to determine the trajectory information of the weighed object on the carrier through the detection signals, it can be specifically implemented through the following two embodiments.

[0031] As Figure 2 shown, Figure 2 is a schematic flowchart of the second embodiment of the detection method for weighing abnormal behavior of this application. The detection method includes the following steps:

[0032] S21: Obtain the detection signals of multiple load cells in the detection device.

[0033] Among them, the detection device includes a horizontally arranged carrier and multiple load cells arranged at intervals under the carrier. The load cell can generate a detection signal in response to the pressure of the weighed object on the carrier. The detection signal is related to the pressure intensity of the object.

[0034] Optionally, the sensor is a resistance strain sensor. Its working principle is that when subjected to pressure, the resistance on the bridge arm of the sensor will change. After this change is filtered and amplified by the hardware circuit, a voltage signal proportional to the pressure it bears is formed.

[0035] S22: Obtain a preset position information table.

[0036] The position information table is a measurement table in which the detected signals and the position information are in one-to-one correspondence and have been measured in advance. Given the known size of the carrier, relevant tests are first carried out to establish a table by corresponding the position information on the carrier with the detection results of multiple detected signals one by one.

[0037] S23: Match the detected signal with the position information table to obtain the position information of the weighed object.

[0038] When the detected signal is obtained, the corresponding position information on the carrier in the position information table is found according to the detected signal.

[0039] S24: Determine the trajectory information according to the position information.

[0040] Optionally, after obtaining the position information of the weighed object on the carrier by the look-up table method, the trajectory information of the weighed object is determined in combination with the movement time of the weighed object on the carrier.

[0041] The relevant velocity information of the weighed object is obtained by fitting through a uniformly accelerated motion model and the least squares method. Combining the information of time and velocity, the trajectory information including motion status information such as motion direction and motion velocity can be obtained.

[0042] S25: Determine whether the weighed object has abnormal motion according to the trajectory information.

[0043] After obtaining the trajectory information of the current weighed object, it is compared with a preset standard threshold to determine whether the trajectory information meets the standard of normal driving. If it does not meet the threshold standard, it is determined that the weighed object has abnormal motion.

[0044] As Figure 3 shown, Figure 3 is a schematic flowchart of the third embodiment of the detection method for weighing abnormal behavior of the present application.

[0045] S31: Obtain the detection signals of multiple weighing sensors in the detection device.

[0046] Among them, the detection device includes a horizontally arranged carrier and multiple weighing sensors spaced apart from each other under the carrier. The weighing sensor can generate a detection signal in response to the pressure of the weighed object on the carrier. The detection signal is related to the pressure intensity of the object.

[0047] Optionally, the sensor is a resistance strain sensor. Its working principle is that when subjected to pressure, the resistance on the bridge arm of the sensor will change. After this change is filtered and amplified by the hardware circuit, a voltage signal proportional to the pressure it bears is formed.

[0048] S32: Obtain the size information of the carrier.

[0049] Obtain the size information of the carrier corresponding to the current load cell.

[0050] S33: Determine the position information of the weighed object according to the size information of the carrier and multiple detection signals.

[0051] Based on the obtained size information of the carrier, combined with the magnitude of the detection signal of the load cell and the proportional relationship therebetween, the position of the weighed object on the carrier can be judged. When the signal magnitudes between the respective load cells or various ratios related to the detection signals are known, the position of the weighed object relative to the size of the carrier in the corresponding direction on the carrier can be obtained as a corresponding ratio.

[0052] S34: Determine the trajectory information according to the position information.

[0053] After obtaining the position information of the weighed object, optionally, combined with the movement time of the weighed object on the carrier, the trajectory information of the weighed object is determined.

[0054] The relevant speed information of the weighed object is obtained through a uniformly accelerated motion model and least squares fitting. Combining the information of time and speed, the trajectory information including motion state information such as motion direction and motion speed can be obtained.

[0055] S35: Determine whether the weighed object has abnormal motion according to the trajectory information.

[0056] After obtaining the trajectory information of the current weighed object, compare it with a preset standard threshold to judge whether the trajectory information meets the standard of normal driving. If it does not meet the threshold standard, it is judged that the weighed object has abnormal motion.

[0057] As Figure 4 shown, Figure 4 is a schematic flowchart of the fourth embodiment of the detection method for weighing abnormal behavior of the present application. This embodiment is a further expansion of step S24 or S34 in the above embodiments, and it can be expanded to include the following steps:

[0058] S41: Obtain the time information corresponding to the position information.

[0059] Obtain the movement time of the weighed object on the carrier, and make the movement time correspond one by one to the position information of the weighed object.

[0060] S42: Obtain the trajectory information of the weighed object according to the position information and the time information.

[0061] By establishing a rectangular coordinate system, all position information can be converted into corresponding XY coordinate values. According to the uniformly accelerated motion model:

[0062] y = v y *t + ay *t 2 / 2, x = v x *t + a x *t 2 / 2

[0063] Substitute the set of coordinate information XY of the position information into the uniformly accelerated motion model, and use the least squares method for fitting to obtain v y , a y , v x , a x and other variables. Then the trajectory information including motion status information such as motion direction and motion speed can be obtained.

[0064] As Figure 5 shown, Figure 5 This is a schematic structural diagram of the carrier of the detection device in an embodiment of the weighing abnormal behavior detection method of the present application.

[0065] The carrier 10 of the detection device is rectangular, and it has four weighing sensors A1, A2, A3, and A4 arranged below. The four weighing sensors are arranged corresponding to the four corners of the rectangular carrier.

[0066] As Figure 6 shown, Figure 6 This is a schematic flowchart of the fifth embodiment of the weighing abnormal behavior detection method of the present application. This embodiment is a specific flowchart of the weighing abnormal behavior detection method in the case of using the carrier of the detection device. The detection method includes the following steps: Figure 5 of the detection device.

[0067] S51: Obtain the voltage signal converted by the current weighing sensor.

[0068] When the weighed object moves on the carrier, obtain the voltage change values V1 - V4 of the weighing sensors A1 - A4. At this time, because the positions of the weighing sensors are different and the positions of the weighed object's movement are different, the voltage change values V1 - V4 are also different.

[0069] S52: Calculate the ratios of the voltage signal in the driving direction and the vertical direction.

[0070] Calculate the ratio R1 of the voltage signal in the forming direction and the ratio R2 in the vertical direction. The specific calculation formulas are:

[0071] R1 = (V1 + V2 - V3 - V4) / (V1 + V2 + V3 + V4)

[0072] R2 = (V2 + V4 - V1 - V3) / (V1 + V2 + V3 + V4)

[0073] S53: Calculate the position information of the weighed object based on the ratios in the driving direction and the vertical direction.

[0074] From the above ratio calculation formula, when R1 is greater than zero and V1 + V2 > V3 + V4, the position of the weighed object on the carrier is more biased towards A1 and A2, so it is higher up, and the larger R1 is, the higher up it is, and vice versa. When R2 is greater than zero and V2 + V4 > V1 + V3, the position of the weighed object on the carrier is more biased towards A2 and A4, so it is more to the right, and the larger R2 is, the more to the right it is, and vice versa. The position of the weighed object on the carrier can be judged based on the positive or negative and magnitude of R1 and R2.

[0075] Optionally, the position of the weighed object on the carrier can be judged by obtaining a preset position information table and combining the positive or negative and magnitude of R1 and R2. This position information table is a measurement table in which the positive or negative and magnitude of R1 and R2 and the position information on the carrier are in one-to-one correspondence. In the case of knowing the size of the carrier, relevant tests are first carried out to establish a table by corresponding the position information on the carrier with the detection results of multiple R1s and R2s one by one. Then, the position information of the weighed object is obtained through the table lookup method.

[0076] Optionally, the position of the weighed object on the carrier can be judged by obtaining the size information of the carrier and combining the positive or negative and magnitude of R1 and R2. Or, the position of the weighed object on the carrier can be judged by combining the voltage signal magnitudes of the weighing sensors A1 - A4 and the ratios between them. In the case of knowing the voltage signals between the weighing sensors or various ratios related to the voltage signals, the position of the weighed object on the carrier in the corresponding direction relative to the size of the carrier can be obtained as a corresponding ratio position.

[0077] S54: Statistically collect all the position information during the time when the weighed object passes over the carrier.

[0078] During the time when the weighed object passes over the carrier, all the position information corresponding to the time is obtained.

[0079] S55: Calculate the movement trajectory based on the time and the position information.

[0080] By establishing a rectangular coordinate system, all the position information can be converted into corresponding XY coordinate values. According to the uniformly accelerated motion model:

[0081] y = v y *t + a y *t 2 / 2, x = v x *t + a x *t 2 / 2

[0082] Substitute the set of XY coordinate information of the position information into the uniformly accelerated motion model, and use the least squares method for fitting to obtain v y 、a y 、v x 、a x and other variables. Then the trajectory information including motion status information such as the motion direction and motion speed can be obtained.

[0083] After obtaining the trajectory information of the current weighed object, compare it with the preset standard threshold to determine whether the trajectory information meets the standard of normal driving. If it does not meet the threshold standard, it is determined as the trajectory information of abnormal driving, and the relevant information is transmitted to other units for processing.

[0084] Optionally, the relevant information can be transmitted to the weighing compensation unit for weighing compensation, or transmitted to the alarm unit to remind of this abnormal driving situation.

[0085] As Figure 7 shown, Figure 7 is the flowchart of the first embodiment of the detection device for weighing abnormal behavior of this application.

[0086] The detection device includes: a carrier 100, a plurality of weighing sensors 110, 120, 130, 140 (here are four exemplary ones), and a control device 150.

[0087] In this embodiment, the carrier 100 is rectangular and horizontally arranged. The four weighing sensors 110, 120, 130, 140 are arranged at intervals below the carrier 100 and are respectively installed corresponding to the four corners of the carrier 100. The control device 150 is connected to the weighing sensors 110, 120, 130, 140 to obtain the detection signals of the weighing sensors 110, 120, 130, 140, and implement the methods described in any one of the first to fifth embodiments of the above detection method and the methods provided by various possible combinations. The positional relationship between the control device 150 and the carrier 100 and / or the weighing sensors 110, 120, 130, 140 is not limited herein.

[0088] It can be understood that the carrier 100 can also be correspondingly set to other shapes such as a square or a circle according to the actual situation. The number of sensors can also be set to at least two according to the actual use situation. The number of sensors and the installation positions are also set according to the shape of the carrier 100 or the calculation requirements of relevant algorithms. Generally, the sensors are arranged as close as possible to the edge of the carrier 100 to achieve a larger linear change region. For example, when the carrier 100 is rectangular, four sensors are arranged at the four corners of the rectangular carrier 100.

[0089] As Figure 8 shown, Figure 8This is a schematic diagram of the structure of the second embodiment of the abnormal weighing behavior detection device of the present application.

[0090] The detection device includes: carriers 200, 300 (here two are exemplary), multiple weighing sensors 210, 220, 230, 240, 310, 320, 330, 340 (here the number of weighing sensors on each carrier is exemplary four), and a control device 400.

[0091] In this embodiment, the carriers 200 and 300 are rectangular and are arranged horizontally side by side. The four weighing sensors 210, 220, 230, 240, 310, 320, 330, 340 are arranged below the carriers 200 and 300 at intervals and are respectively equipped at the four corners of the carriers 200 and 300. The control device 400 is connected to all the weighing sensors 210, 220, 230, 240, 310, 320, 330, 340 to obtain the detection signals of the weighing sensors 210, 220, 230, 240, 310, 320, 330, 340, and realize the method described in any one of the first to fifth embodiments of the above detection method and the method provided by various possible combinations. The positional relationship between the control device 400 and the carriers 200 , 300 and / or the weighing sensors 210 , 220 , 230 , 240 , 310 , 320 , 330 , 340 is not limited herein.

[0092] In this embodiment, when the weighing object is an ordinary vehicle, the carrier 200 and the carrier 300 correspond to the left and right tires of the vehicle respectively, so as to obtain the track information of the left and right tires of the vehicle respectively.

[0093] It is understood that the carrier 200, 300 can also be set to other shapes such as square, circle, etc. according to actual conditions. The number of sensors can also be set to at least two according to actual use conditions. The number of sensors and the setting positions are also set according to the shape of the carrier 200, 300 or the calculation requirements of the relevant algorithm. Generally, the sensors are set as close to the edge of the carrier 200, 300 as possible to achieve a larger linear change area. For example, when the carrier 200, 300 is rectangular, four sensors are set at the four corners of the rectangular carrier.

[0094] To sum up, through the above embodiments, by setting a weighing sensor under the horizontal carrier, the detection signal generated by the weighing sensor in response to the pressure of the weighing object is obtained, the position information of the object is determined according to the detection signal, and then the trajectory information of the weighing object is obtained in combination with the time information, so as to judge whether the movement behavior of the weighing object is abnormal, which is less affected by external interference factors, has high accuracy and good stability.

[0095] In several embodiments provided by the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0096] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0097] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0098] If the integrated units in the above other embodiments are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0099] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A detection method for abnormal weighing behavior, characterized in that, Including: Obtaining detection signals of multiple weighing sensors in a detection device; wherein, the detection device includes a horizontally arranged carrier and the multiple weighing sensors spaced apart from each other under the carrier, and the weighing sensors generate the detection signals in response to the pressure of a weighed object on the carrier; Determining trajectory information of the weighed object on the carrier according to the detection signals; Determining whether the weighed object has abnormal movement according to the trajectory information; Wherein, the determining the trajectory information of the weighed object on the carrier according to the detection signals includes: Obtaining size information of the carrier; Determining position information of the weighed object according to the size information of the carrier and the multiple detection signals; Determining the trajectory information according to the position information; Wherein, the determining the position information of the weighed object according to the size information of the carrier and the multiple detection signals includes: Obtaining, through the obtained size information of the carrier, in combination with the magnitudes of the detection signals and the proportional relationship therebetween, the position of the weighed object on the carrier in a corresponding direction relative to the corresponding proportion of the size of the carrier; Wherein, the corresponding direction of the weighed object on the carrier includes the driving direction and the vertical direction.

2. The detection method according to claim 1, wherein The determining the trajectory information according to the position information includes: Obtaining time information corresponding to the position information; Obtaining the trajectory information of the weighed object according to the position information and the time information.

3. The detection method according to claim 2, wherein The obtaining the trajectory information of the weighed object according to the position information and the time information includes: Processing the position information and the time information using a uniformly accelerated model and the least squares method to obtain the trajectory information of the weighed object.

4. The detection method according to claim 1, wherein The detection signal is a voltage signal.

5. The detection method according to claim 1, wherein The trajectory information includes at least one of position information, time information, speed information, and acceleration information of the weighed object.

6. A detection device for abnormal weighing behavior, characterized in that, The detection device includes: A carrier, the carrier being horizontally arranged; Multiple weighing sensors spaced apart from each other, the multiple weighing sensors are respectively arranged below the carrier, and the weighing sensors are used to generate detection signals in response to the pressure of a weighed object on the carrier; A control device, connected to the multiple weighing sensors, for obtaining the detection signals and for executing the method according to any one of claims 1 - 5 to determine whether a weighed object on the carrier has abnormal movement.

7. The detection device according to claim 6, wherein The weighed object is a vehicle; The carrier includes: A first carrier; A second carrier, the first carrier and the second carrier are arranged in parallel to respectively correspond to the left and right tires of the vehicle; Wherein, the multiple weighing sensors are respectively arranged below the first carrier and the second carrier.

8. The detection device according to claim 7, wherein The first carrier and the second carrier are rectangular; The number of the plurality of load cells is eight, and the plurality of load cells are respectively arranged corresponding to four corners of the first carrier and the second carrier.

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