Steel-aluminum hybrid vehicle body structure of unmanned vehicle

Abstract

The invention relates to the technical field of vehicle body structures, in particular to a steel-aluminum hybrid vehicle body structure of an unmanned vehicle, which comprises an underframe, side wing plates, a front baffle plate, a rear baffle plate and a skylight connecting plate, the number of the side wing plates is two, the two side wing plates are connected to the two sides of the bottom frame correspondingly, and the two side wing plates are each provided with a hub avoiding area. The front baffle is connected to the front ends of the two side wing plates and is close to the bottoms; the rear baffle is connected to the rear ends of the two side wing plates and close to the bottoms of the side wing plates, the rear baffle is obliquely arranged, and the top of the rear baffle is behind the bottom of the rear baffle; the bottom of the rear end of the skylight connecting plate is connected to the top of the rear baffle, the top face of the skylight connecting plate is an arc face, and the skylight connecting plate and the rear baffle are in smooth transition. The inclined design of the rear baffle and the smooth transition of the skylight connecting plate can improve aerodynamic characteristics, can effectively guide airflow, reduces air resistance and turbulence at the tail of a vehicle, and improves stability during high-speed driving.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle body structures, and in particular to a steel-aluminum hybrid vehicle body structure of an unmanned vehicle. Background Art

[0002] The use of aluminum reduces vehicle weight, allowing unmanned vehicles to carry more equipment (such as batteries, sensors) without sacrificing range or power performance.

[0003] The application document with publication number CN117901954A discloses a vehicle body structure, comprising: a roof side assembly and an exterior decorative member, wherein the roof side assembly is connected to the upper end of the pillar of the vehicle body along the front-rear direction of the vehicle body, and the roof side assembly constitutes the A-pillar of the vehicle body; the exterior decorative member is joined to the outer side of the roof side assembly; wherein the roof side assembly comprises: a pipe, an upper reinforcing member, a lower reinforcing member and an inner reinforcing member, wherein the pipe has a closed cross-sectional shape and is extended in the front-rear direction of the vehicle body to form a closed cross-sectional shape; the upper reinforcing member is joined to the upper side of the pipe and is extended in the front-rear direction of the vehicle body; the lower reinforcing member is joined to the lower side of the pipe and is extended in the front-rear direction of the vehicle body; the inner reinforcing member is joined to the inner side of the pipe of the vehicle body and is extended in the front-rear direction of the vehicle body.

[0004] The tail design of the vehicle body in the prior art cannot guide the airflow, resulting in greater resistance during the vehicle's driving. Summary of the invention

[0005] The purpose of the present invention is to propose a steel-aluminum hybrid body structure for an unmanned vehicle in view of the above-mentioned deficiencies.

[0006] The present invention adopts the following technical solution:

[0007] A steel-aluminum hybrid body structure of an unmanned vehicle, the structure comprising a chassis, side fenders, a front fender, a rear fender and a sunroof connecting plate; two side fenders are provided, the two side fenders are respectively connected to the two sides of the chassis, and the two side fenders are both provided with a wheel hub avoidance area; the front fender is connected to the front ends of the two side fenders and is close to their bottoms; the rear fender is connected to the rear ends of the two side fenders and is close to their bottoms, the rear fender is inclined, and the top of the rear fender is behind the bottom of the rear fender; the bottom of the rear end of the sunroof connecting plate is connected to the top of the rear fender, the top surface of the sunroof connecting plate is an arc surface, and the sunroof connecting plate and the rear fender are smoothly transitioned.

[0008] Optionally, the skylight connecting plate is connected to the tailgate to form a mirror-image C-shaped structure.

[0009] Optionally, the angle formed by the connection between the sunroof connecting plate and the tailgate is compared with an ideal index of the rear angle of the vehicle to determine whether the rear design of the vehicle is reasonable.

[0010] Optionally, when calculating the ideal index of the rear end angle, the following steps are included: S1: the visual detection module detects and obtains the horizontal difference between the highest point and the lowest point of the rear end and the height difference between the highest point and the lowest point of the rear end, and transmits them to the control module; S2: the information storage module stores the benchmark air resistance coefficient, the windward projection area of ​​the front of the vehicle, the projection area of ​​the rear of the vehicle, the air pressure difference between the front and the rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the height of the center of gravity of the vehicle and the vehicle wheelbase, and transmits them to the control module; S3: the control module obtains the ideal index of the rear end angle based on the horizontal difference between the highest point and the lowest point of the rear end, the height difference between the highest point and the lowest point of the rear end, the benchmark air resistance coefficient, the windward projection area of ​​the front of the vehicle, the projection area of ​​the rear of the vehicle, the air pressure difference between the front and the rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the height of the center of gravity of the vehicle and the vehicle wheelbase, and transmits the ideal index of the rear end angle to the communication module; S4: the communication module transmits the ideal index of the rear end angle to the user end.

[0011] Optionally, in step S1, the visual detection module includes an image acquisition submodule, a data acquisition submodule, a target point detection submodule and a calculation submodule; the image acquisition submodule is used to capture an image of the rear of the vehicle; the data acquisition submodule obtains point cloud data of the rear of the vehicle based on the image of the rear of the vehicle; the target point detection submodule analyzes the point cloud data of the parking space and finds the highest point and the lowest point of the rear of the vehicle; the calculation submodule analyzes the highest point and the lowest point of the rear of the vehicle and obtains the horizontal difference between the highest point and the lowest point of the rear of the vehicle and the height difference between the highest point and the lowest point of the rear of the vehicle, and transmits them to the control module.

[0012] Optionally, the control module calculates the ideal index of the rear angle by referring to the following formula:

[0013]

[0014] Among them, Deg is the ideal index of the rear angle, sp is the horizontal difference between the highest point and the lowest point of the rear, bzk is the reference air resistance coefficient, s q is the front windward projection area of ​​the vehicle, s h is the projection area of ​​the rear of the vehicle, p is the pressure difference between the front and rear of the vehicle, θ is the vehicle roll angle, gd is the height difference between the highest and lowest points of the rear of the vehicle, bzs is the standard lift coefficient, zxg is the height of the center of gravity of the vehicle, and zj is the vehicle wheelbase.

[0015] The beneficial effects achieved by the present invention are:

[0016] 1. The tilted design of the tailgate and the smooth transition of the sunroof connecting plate can improve aerodynamic characteristics, effectively guide airflow, reduce air resistance and turbulence at the rear of the vehicle, and improve stability when driving at high speeds;

[0017] 2. The C-shaped structure provides good mechanical properties, can effectively disperse the impact or load pressure, and improve the overall body's anti-deformation ability;

[0018] 3. By comparing the rear of the vehicle with the ideal rear angle index, the system can automatically evaluate whether the rear design meets the aerodynamic and vehicle performance requirements, and realize intelligent design analysis;

[0019] 4. The system automatically calculates the rear angle of the vehicle, greatly reducing the complex work based on experience and multiple tests in traditional design, saving design time and cost.

[0020] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the vehicle body structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the overall structure of the vehicle body structure of the present invention from another angle;

[0023] Figure 3 is a side view of the vehicle body structure of the present invention;

[0024] Figure 4 is a flow chart of the method of the present invention;

[0025] Figure 5 It is a structural schematic diagram of the visual detection module in the present invention;

[0026] Figure 6 This is a flow chart of the method of Embodiment 2 of the present invention;

[0027] Figure 7 It is a structural diagram of a speed analysis module in the second embodiment of the present invention;

[0028] Figure 8 Schematic diagram of the structure of the deformation analysis module in the second embodiment of the present invention;

[0029] Fig. 9 This is a rendering of the second embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 100, chassis;

[0032] 200, side wing panels;

[0033] 300, front baffle;

[0034] 400, tailgate;

[0035] 500. Skylight connecting plate. DETAILED DESCRIPTION

[0036] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0037] Embodiment 1: This embodiment provides a steel-aluminum hybrid body structure of an unmanned vehicle, combined with Figures 1 to 5 shown.

[0038] A steel-aluminum hybrid body structure of an unmanned vehicle, the structure comprising a chassis 100, side fenders 200, a front fender 300, a rear fender 400 and a sunroof connecting plate 500; two side fenders 200 are provided, the two side fenders 200 are respectively connected to the two sides of the chassis 100, and the two side fenders 200 are both provided with a wheel hub avoidance area; the front fender 300 is connected to the front ends of the two side fenders 200 and is close to their bottoms; the rear fender 400 is connected to the rear ends of the two side fenders 200 and is close to their bottoms, the rear fender 400 is inclined, and the top of the rear fender 400 is behind the bottom of the rear fender 400; the bottom of the rear end of the sunroof connecting plate 500 is connected to the top of the rear fender 400, the top surface of the sunroof connecting plate 500 is an arc surface, and the sunroof connecting plate 500 and the rear fender 400 are smoothly transitioned.

[0039] Optionally, the sunroof connecting plate 500 is connected to the tailgate 400 to form a C-shaped mirror image structure.

[0040] Optionally, the angle formed by the connection between the sunroof connecting plate 500 and the tailgate 400 is compared with an ideal index of the rear angle of the vehicle to determine whether the rear design of the vehicle is reasonable.

[0041] Optionally, when calculating the ideal index of the rear end angle, the following steps are included: S1: the visual detection module detects and obtains the horizontal difference between the highest point and the lowest point of the rear end and the height difference between the highest point and the lowest point of the rear end, and transmits them to the control module; S2: the information storage module stores the benchmark air resistance coefficient, the windward projection area of ​​the front of the vehicle, the projection area of ​​the rear of the vehicle, the air pressure difference between the front and the rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the height of the center of gravity of the vehicle and the vehicle wheelbase, and transmits them to the control module; S3: the control module obtains the ideal index of the rear end angle based on the horizontal difference between the highest point and the lowest point of the rear end, the height difference between the highest point and the lowest point of the rear end, the benchmark air resistance coefficient, the windward projection area of ​​the front of the vehicle, the projection area of ​​the rear of the vehicle, the air pressure difference between the front and the rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the height of the center of gravity of the vehicle and the vehicle wheelbase, and transmits the ideal index of the rear end angle to the communication module; S4: the communication module transmits the ideal index of the rear end angle to the user end.

[0042] Optionally, in step S1, the visual detection module includes an image acquisition submodule, a data acquisition submodule, a target point detection submodule and a calculation submodule; the image acquisition submodule is used to capture an image of the rear of the vehicle; the data acquisition submodule obtains point cloud data of the rear of the vehicle based on the image of the rear of the vehicle; the target point detection submodule analyzes the point cloud data of the parking space and finds the highest point and the lowest point of the rear of the vehicle; the calculation submodule analyzes the highest point and the lowest point of the rear of the vehicle and obtains the horizontal difference between the highest point and the lowest point of the rear of the vehicle and the height difference between the highest point and the lowest point of the rear of the vehicle, and transmits them to the control module.

[0043] Optionally, the control module calculates the ideal index of the rear angle by referring to the following formula:

[0044]

[0045] Among them, Deg is the ideal index of the rear angle, sp is the horizontal difference between the highest point and the lowest point of the rear, bzk is the reference air resistance coefficient, s q is the front windward projection area of ​​the vehicle, s h is the projection area of ​​the rear of the vehicle, p is the pressure difference between the front and rear of the vehicle, θ is the vehicle roll angle, gd is the height difference between the highest and lowest points of the rear of the vehicle, bzs is the standard lift coefficient, zxg is the height of the center of gravity of the vehicle, and zj is the vehicle wheelbase.

[0046] When the control module calculates the ideal index of the rear angle, it refers to the following program code:

[0047]

[0048]

[0049] Specifically, for the finished vehicle, the test calculates the ideal index of the rear angle, and technical personnel in this field determine whether the rear design of the vehicle is reasonable by comparing the ideal index of the rear angle with the actual value of the rear angle (the angle formed by the connection between the sunroof connecting plate 500 and the tailgate 400). It is assumed that the larger the difference between the ideal index of the rear angle and the actual value of the rear angle, the more unreasonable it is. The ideal index of the rear angle can be used as a reference for subsequent updated and iterated vehicles; the rear angle refers to.

[0050] The following principles shall be referred to when calculating the "horizontal difference between the highest and lowest points of the rear of the vehicle": the "highest point of the rear of the vehicle" refers to the highest point along the top above the rear window. Assuming that the corresponding vehicle has no rear window, it refers to the highest point along the top above the rear wheels. The "lowest point of the rear of the vehicle" refers to the lowest point of the rear bumper. The units of the horizontal difference between the highest and lowest points of the rear of the vehicle and the height difference between the highest and lowest points of the rear of the vehicle are meters.

[0051] The benchmark air drag coefficient and the standard lift coefficient are obtained through wind tunnel experimental tests. For example, a vehicle model is made using a three-dimensional modeling tool, and then the model is fixed on a wind tunnel test bench. The test bench is connected to a multi-axis force sensor, which can simultaneously measure air drag and lift. The wind speed is then set according to the experimental requirements. The wind speed can be set to 40 meters per second. The wind tunnel is started, and the air drag and lift readings of the force sensor are recorded. The corresponding benchmark air drag coefficient and standard lift coefficient can then be calculated. In this embodiment, the benchmark air drag coefficient is 0.3, and the standard lift coefficient is -0.2.

[0052] The units of the front windward projection area and the rear windward projection area are both square meters; "front windward projection area" refers to the projection area of ​​the front of the vehicle (perpendicular to the forward direction of the vehicle body) on a two-dimensional plane, which reflects the cross-sectional area of ​​the front of the vehicle in direct contact with the air; "rear projection area" refers to the projection area of ​​the rear of the vehicle (perpendicular to the forward direction of the vehicle body) on a two-dimensional plane, which reflects the size of the vehicle rear affecting the airflow separation; the front windward projection area and the rear projection area can be obtained by querying the factory data, or technical personnel in this field can use mapping software to extract the front and rear contours of the vehicle along the forward and rear directions of the vehicle, and the software will calculate the corresponding contour area.

[0053] The air pressure difference between the front and rear of the vehicle describes the difference between the static pressure at the front (front) and rear (rear) of the vehicle. The difference is caused by the disturbance of the air during the movement of the vehicle, and is mainly composed of the high-pressure area at the front of the vehicle and the low-pressure area at the rear of the vehicle. It can be obtained through wind tunnel experiments. For example, a group of static pressure sensors are set in the direction of the vehicle's forward movement to record the static pressure in the high-pressure area at the front of the vehicle, and another group of static pressure sensors are set in the low-pressure area at the rear of the vehicle to record the static pressure in the low-pressure area at the rear of the vehicle. Finally, the air pressure difference between the front and rear of the vehicle is calculated; the unit of the air pressure difference between the front and rear of the vehicle is Pascal.

[0054] The vehicle roll angle refers to the roll angle that the vehicle may have during dynamic driving, and refers to the angle formed between the longitudinal center plane of the vehicle and the ground normal; the longitudinal center plane of the vehicle refers to a vertical plane passing through the center line of the vehicle (running through the front and rear of the vehicle) and perpendicular to it. When not rolling, the plane is perpendicular to the ground; when not rolling, the longitudinal center plane of the vehicle and the ground normal are coincident or parallel; when the vehicle is subjected to lateral force (such as high-speed turning or crosswind), the body will tilt to one side. At this time, the longitudinal center plane of the vehicle is no longer parallel to the ground normal, but forms an angle, which is the vehicle roll angle. It can be obtained through dynamic simulation tools. A roll angle exceeding the normal range may cause the vehicle to lose control or roll over. From the perspective of the vehicle's dynamic characteristics, the larger the vehicle's roll angle, the greater the tilt of the vehicle body during turning or dynamic driving. This tilt changes the actual spatial geometric distribution of the rear of the vehicle, requiring additional tilt compensation in the rear design to maintain aerodynamic efficiency. From an aerodynamic analysis, a larger vehicle roll angle will lead to asymmetric airflow distribution, especially at the rear of the vehicle. In order to ensure smooth separation of the airflow at the rear of the vehicle, the rear inclination angle will increase the corresponding angle in the design to compensate for this asymmetry. From the perspective of center of gravity shift, when the vehicle's roll angle becomes larger, the vehicle's center of gravity shifts outward, which will cause the designed tilt angle of the rear of the vehicle to appear larger under dynamic conditions, thereby balancing the vehicle's stability.

[0055] The unit of vehicle center of gravity height and vehicle wheelbase is meter; "Vehicle wheelbase" is the horizontal distance between the front axle and the rear axle of the vehicle.

[0056] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0057] This embodiment solves the problem of poor wind-conducting ability of traditional vehicle body structures. The inclined design of the tailgate 400 and the smooth transition of the sunroof connecting plate 500 can improve aerodynamic characteristics, effectively guide airflow, reduce air resistance and turbulence at the rear of the vehicle, and improve stability during high-speed driving.

[0058] Embodiment 2: This embodiment includes all the contents of Embodiment 1, and provides a steel-aluminum hybrid body structure of an unmanned vehicle, combined with Figures 6 to 9 shown.

[0059] A steel-aluminum hybrid body structure of an unmanned vehicle, after the structure is connected, a collision test is performed to obtain an impact force index of the rear end of the vehicle during a collision process, and information on whether the impact resistance of the rear end of the vehicle is good or poor is obtained according to the impact force index of the rear end of the vehicle during a collision process, including the following steps:

[0060] A1: The speed analysis module analyzes the relative speed between the impact object and the rear of the vehicle and the anti-collision speed of the rear of the vehicle, and transmits them to the data processing module;

[0061] A2: The deformation analysis module analyzes the deformation of a test plate at the rear of the vehicle along its length direction and the deformation of a test plate at the rear of the vehicle along its width direction, and transmits them to the data processing module;

[0062] A3: The dimension storage module is used to store the length and width of a test plate at the rear of the vehicle and transmit them to the data processing module;

[0063] A4: The data processing module obtains the impact force index of the rear of the vehicle during the collision process according to the relative speed between the impact object and the rear of the vehicle, the anti-collision speed of the rear of the vehicle, the deformation of a certain test plate of the rear of the vehicle along its length direction, the deformation of a certain test plate of the rear of the vehicle along its width direction, the length of a certain test plate of the rear of the vehicle and the width of a certain test plate of the rear of the vehicle, and transmits the impact force index of the rear of the vehicle during the collision process to the determination module;

[0064] A5: The determination module obtains information on whether the rear end of the vehicle has good or poor anti-collision capability according to the impact force index of the rear end of the vehicle during the collision process, and transmits the information on whether the rear end of the vehicle has good or poor anti-collision capability to the user end.

[0065] Specifically, in step A5, the determination module refers to the following principles when making a determination: when the impact force index of the rear end of the vehicle during the collision process is greater than or equal to a selection threshold of the impact force index of the rear end of the vehicle during the collision process, it indicates that the anti-collision ability of the rear end of the vehicle is poor; when the impact force index of the rear end of the vehicle during the collision process is less than the selection threshold of the impact force index of the rear end of the vehicle during the collision process, it indicates that the anti-collision ability of the rear end of the vehicle is good; the selection threshold of the impact force index of the rear end of the vehicle during the collision process is set by technical personnel in this field.

[0066] Optionally, in step A1, the speed analysis module includes a speed sensing submodule, a displacement sensing submodule, a time sensing submodule and an analysis submodule;

[0067] The speed sensor submodule is used to detect the speed of the impact object and the speed of the rear of the vehicle, and obtain the relative speed between the impact object and the rear of the vehicle according to the speed of the impact object and the speed of the rear of the vehicle, and transmit it to the data processing module;

[0068] The displacement sensing submodule is installed at both ends of the target position, records the displacement data at both ends of the target position during the collision, obtains the deformation of the rear end of the vehicle based on the displacement data at both ends of the target position, and transmits the deformation of the rear end of the vehicle to the analysis submodule;

[0069] The time sensing submodule is used to detect and obtain the duration of the collision contact, and transmit the duration of the collision contact to the analysis submodule;

[0070] The analysis submodule divides the deformation of the rear end of the vehicle by the duration of the collision contact to obtain the anti-collision speed of the rear end of the vehicle and transmits it to the data processing module.

[0071] Optionally, in step A2, the deformation analysis module includes a scanning submodule and a comparison submodule;

[0072] The scanning submodule scans a test plate in the parking space before and after the collision test and generates initial point cloud data and deformed point cloud data;

[0073] The comparison submodule obtains the deformation of a test plate at the rear of the vehicle along its length direction and the deformation of a test plate at the rear of the vehicle along its width direction based on the initial point cloud data and the deformed point cloud data, and transmits them to the data processing module.

[0074] Optionally, when the data processing module calculates the impact force index of the rear end of the vehicle during the collision process, the following formula is satisfied:

[0075]

[0076] Among them, F is the impact force index of the rear end of the vehicle during the collision process, v impact is the relative speed between the impact object and the rear of the vehicle, v crash is the anti-collision speed of the rear of the vehicle, bx cd is the deformation of a test plate at the rear of the vehicle along its length, cd is the length of a test plate at the rear of the vehicle, bx kd is the deformation of a test plate at the rear of the vehicle along its width direction, and kd is the width of a test plate at the rear of the vehicle.

[0077] When calculating the data processing module, refer to the following program code:

[0078]

[0079]

[0080] Specifically, the units of the relative speed between the impact object and the rear end of the vehicle and the anti-impact speed of the rear end of the vehicle are both meters per second; the deformation of a test plate at the rear end of the vehicle along its length direction, the length of a test plate at the rear end of the vehicle, the deformation of a test plate at the rear end of the vehicle along its width direction and the width of a test plate at the rear end of the vehicle are all meters; when calculating the impact force index of the rear end of the vehicle during the collision process, the test plate selected at the rear end of the vehicle corresponds to the same test plate, and technical personnel in this field give priority to selecting a test plate that conforms to the shape of the rear end of the vehicle, such as the tailgate 400; assuming that different test plates are selected for the same vehicle to obtain different index data, technical personnel in this field can make choices based on different index data.

[0081] The above units are only examples, and those skilled in the art may set different units according to actual needs when implementing this solution.

[0082] This embodiment solves the problem of the lack of impact testing in traditional vehicle body structures. By analyzing the impact force index, the anti-impact performance of the rear end of the vehicle can be quickly judged, providing clear feedback for R&D or design personnel.

[0083] The contents disclosed above are only preferred feasible embodiments of the present invention, and do not limit the protection scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the protection scope of the present invention. In addition, the elements therein can be updated as technology develops.

Claims

1. A steel-aluminum hybrid body structure for an unmanned vehicle, characterized in that: The structure includes a base frame, side wing panels, a front fender, a rear fender, and a sunroof connecting panel; There are two side wing plates, which are respectively connected to two sides of the chassis, and both side wing plates are provided with a wheel hub avoidance area; The front baffle is connected to the front ends of the two side wing plates and is close to the bottoms thereof; The rear baffle is connected to the rear ends of the two side wing plates and is close to the bottom thereof. The rear baffle is arranged in an inclined manner, and the top of the rear baffle is behind the bottom of the rear baffle. The bottom of the rear end of the skylight connecting plate is connected to the top of the rear baffle, the top surface of the skylight connecting plate is an arc surface, and the skylight connecting plate and the rear baffle are in a smooth transition.

2. The steel-aluminum hybrid body structure of an unmanned vehicle as claimed in claim 1, characterized in that: The sunroof connecting plate is connected to the rear baffle to form a C-shaped mirror image structure.

3. The steel-aluminum hybrid body structure of an unmanned vehicle as claimed in claim 2, characterized in that: The angle formed by the connection between the sunroof connecting plate and the tailgate is compared with the ideal index of the rear angle of the vehicle to determine whether the rear design of the vehicle is reasonable.

4. The steel-aluminum hybrid body structure of an unmanned vehicle as claimed in claim 3, characterized in that: When calculating the ideal index of the rear angle, The following steps are involved: S1: The visual detection module detects and obtains the horizontal difference between the highest point and the lowest point of the rear of the vehicle and the height difference between the highest point and the lowest point of the rear of the vehicle, and transmits them to the control module; S2: The information storage module stores the reference air resistance coefficient, the front windward projection area, the rear projection area, the air pressure difference between the front and rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the vehicle center of gravity height and the vehicle wheelbase, and transmits them to the control module; S3: The control module obtains an ideal index of the rear angle according to the horizontal difference between the highest point and the lowest point of the rear of the vehicle, the height difference between the highest point and the lowest point of the rear of the vehicle, the reference air resistance coefficient, the front windward projection area, the rear projection area, the air pressure difference between the front and rear of the vehicle, the vehicle roll angle, the standard lift coefficient, the vehicle center of gravity height and the vehicle wheelbase, and transmits the ideal index of the rear angle to the communication module; S4: The communication module transmits the ideal index of the rear angle of the vehicle to the user end.

5. The steel-aluminum hybrid body structure of an unmanned vehicle as claimed in claim 4, characterized in that: In step S1, the visual detection module includes an image acquisition submodule, a data acquisition submodule, a target point detection submodule and a calculation submodule; The image acquisition submodule is used to capture the image of the rear of the vehicle; The data acquisition submodule obtains point cloud data of the rear of the vehicle based on the rear image analysis; The target point detection submodule analyzes the point cloud data of the parking space and finds the highest point and the lowest point of the rear of the vehicle; The calculation submodule analyzes the highest point and the lowest point of the rear of the vehicle and obtains the horizontal difference between the highest point and the lowest point of the rear of the vehicle and the height difference between the highest point and the lowest point of the rear of the vehicle, and transmits the results to the control module.

6. The steel-aluminum hybrid body structure of an unmanned vehicle as claimed in claim 4, characterized in that: The control module calculates the ideal index of the rear angle by referring to the following formula: Among them, Deg is the ideal index of the rear angle, sp is the horizontal difference between the highest point and the lowest point of the rear, bzk is the reference air resistance coefficient, s q is the front windward projection area of ​​the vehicle, s h is the projection area of ​​the rear of the vehicle, p is the pressure difference between the front and rear of the vehicle, θ is the vehicle roll angle, gd is the height difference between the highest and lowest points of the rear of the vehicle, bzs is the standard lift coefficient, zxg is the height of the center of gravity of the vehicle, and zj is the vehicle wheelbase.

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