A whole vehicle posture design and verification system and method

Abstract

This invention discloses a vehicle attitude design and verification system and method, relating to the automotive field. It includes a test bench, a tooling frame, pressure sensors, and position sensors. The test bench is equipped with multiple support plates for supporting the wheels. These support plates have a lifting function, and the different frequencies of lifting and lowering of the multiple support plates simulate the stress release of the suspension when the vehicle passes over a tortuous road. The tooling frame is located on the upper side of the test bench and provides mounting points for the suspension. The pressure sensors are located at the contact points between the tooling frame and the suspension, used to detect the pressure on the springs in the suspension. The position sensors are used to detect the wheel center coordinates and the wheel center height above the ground. This invention verifies the vehicle attitude in its designed state and corrects the ground line and spring parameters, ensuring that the designed suspension meets the design values ​​and controlling the ground clearance or wheel arch clearance at the front and rear wheels within a smaller tolerance range.

Description

Technical Field

[0001] This invention relates to the automotive field, and more particularly to a vehicle posture design and verification system and method. Background Technology

[0002] The vehicle's attitude (Z-axis) directly determines its overall coordination. Furthermore, with increasingly stringent regulations, the ground clearance at the front and rear wheels and the overall vehicle height must meet regulatory requirements. For example, in a collision, the vehicle's attitude must conform to the design (tolerance ±10mm). New cars undergo random checks during registration to ensure their overall height meets regulatory requirements. Therefore, the design and verification of the vehicle's attitude has become an indispensable part of the automotive development and design process.

[0003] Taking a MacPherson strut and multi-link rear suspension as an example, typically, OEMs need to draw ground lines in the early stages of vehicle development to determine the overall vehicle attitude. After the wheel centers are defined, the ground lines are determined based on tire type, tire stiffness, and suspension stiffness, and the resulting wheel arch clearance, overall vehicle height, and ground clearance at the front and rear wheels under various loads are calculated. The chassis specialists design the springs in the suspension based on the axle loads, including spring length and load. Simulation specialists calculate suspension stiffness, usually using CATIA & Adams software. Tire size and stiffness are provided by the supplier. Once the prototype vehicle is in place, a real-vehicle test is conducted based on the previously designed ground lines to confirm the rationality of the suspension design and the accuracy of the ground lines. Because the suspension is a series of elastic components with a long dimensional chain, each vehicle is different, often resulting in varying real-vehicle performance. When troubleshooting real-vehicle issues, it is often difficult to pinpoint the root cause. The only solution is to adjust the spring length to approximate the design value. Since the tire formula is fixed by the manufacturer, the size and stiffness are difficult to adjust. The only solution is to adjust the ground line to absorb the difference between the actual product and the initial theoretical value.

[0004] During the actual vehicle measurement phase, stress release of the entire vehicle's suspension is typically performed first, achieved by running on a test track's twisting circuit. However, it's uncertain how many laps are needed for complete stress release, and track resources are limited, making unlimited twisting circuit testing impossible. After suspension stress release, actual vehicle attitude measurement is performed, requiring a level surface, counterweights, and the use of rulers, laser rangefinders, etc. However, due to the complexity of the measurement conditions, implementation requires significant manpower, and the measurement methods have relatively low accuracy, easily leading to interference in judgment. Furthermore, the positive and negative tolerances of individual suspension components of the selected vehicle are difficult to determine. When the overall attitude of a single or several vehicles approaches its limits, it's impossible to determine whether the cause is due to cumulative tolerances or design deviations.

[0005] The tolerance for ground clearance / wheel arch clearance in the overall vehicle posture is typically defined as ±10mm. During acceptance testing, the selected vehicle meets the requirements. However, because the same spring needs to cover configurations with different weights, there may be out-of-tolerance issues in some configurations (weight differences), resulting in significant posture deviations and abnormal overall vehicle posture. If springs of different lengths are developed for different configurations, there will be too many types of suspensions (spring differences), making error prevention difficult in the factory. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a vehicle attitude design and verification system and method, which verifies the vehicle attitude in the design state and corrects the ground line and spring parameters so that the designed suspension can meet the design values ​​and control the ground clearance or wheel arch clearance of the front and rear wheels of the vehicle within a smaller tolerance range.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, embodiments of the present invention provide a vehicle attitude design and verification system, including a test bench, a tooling frame, a pressure sensor, and a position sensor; The test bench is equipped with multiple support plates for supporting the wheels. The support plates have a lifting function. By raising and lowering the multiple support plates at different frequencies, the stress of the suspension is released by simulating the vehicle passing over a tortuous road. The tooling frame is set on the upper side of the test bench and is used to provide the mounting points for the suspension. The pressure sensor is installed at the contact position between the tooling frame and the suspension to detect the pressure borne by the spring in the suspension; the position sensor is used to detect the wheel center coordinates and the wheel center height above the ground.

[0008] As a further implementation, the test bench includes a horizontally arranged flat plate body, which is connected to four liftable support plates; The support plate is parallel to the flat plate body and is also used to detect vehicle load.

[0009] As a further implementation, a position signal receiver corresponding to the support plate is installed on the outer side of the flat plate body. The signal receiver is used to receive the detection signal of the position sensor to obtain the Z-axis coordinate of the wheel center and the height of the wheel center above the ground.

[0010] As a further implementation, the tooling frame includes an upper body and a lower body, which are connected by multiple connecting columns. The bottom of the upper body is connected to multiple support columns, which are used to apply pressure to the suspension.

[0011] As a further implementation, a computer is also included, which is used to fit the actual ground line state based on the vehicle's ground line parameters.

[0012] Secondly, embodiments of the present invention also provide a method for designing and verifying the posture of a vehicle, employing the aforementioned system, including: The suspension stress is released by the up-and-down oscillation based on the four support plates. The support plate is lowered until the load on its support surface is 0, and the height Z0 of the front and rear wheel centers from the support plate is detected; then the support plate is lowered to the same height as the plate body. The test bench moves upward as a whole and monitors the axle loads of the front and rear wheels; under different working conditions, set loads are applied to the front and rear wheels, and the Z-axis coordinate of the wheel center, the height of the wheel center off the ground, and the spring loads of the front and rear wheels are detected; Based on the acquired measurement data, a physical ground line is generated and compared with the theoretical ground line to obtain key parameters for suspension design.

[0013] As a further implementation, the different operating conditions include three conditions: no load, half load, and full load. In the unloaded condition, the front wheels are loaded with an unloaded load at K1, and the rear wheels are loaded with an unloaded load at K2. In the half-load condition, the front wheels are loaded with a half-load at K3, and the rear wheels are loaded with an unloaded load at K4; Under the full load condition, the front wheels are fully loaded to K5, and the rear wheels are fully loaded to K6.

[0014] As a further implementation method, springs with different stiffnesses are selected, and multiple sets of curves showing the relationship between shaft load variation and spring load variation are selected to generate approximate formulas.

[0015] As a further implementation, the approximate formula is compared with the theoretical calculation formula, and a correction amount is added.

[0016] As a further implementation, the mounting point of the suspension in the tooling frame is located at the designed position in the vehicle coordinate system.

[0017] The beneficial effects of this invention are as follows: (1) In the early stage of vehicle development, the present invention sets up a tooling test bench to design and measure the vehicle attitude. The vehicle attitude design and verification system includes a test bench, a tooling frame, and pressure sensors and position sensors. The test bench and tooling frame can connect the suspension with rigid parts to ensure that the hard points are consistent with the vehicle state and can load loads. Combined with pressure sensors and position sensors, the system simulates the vehicle load and stress conditions, and has vibration function to fully release suspension stress, thereby verifying the vehicle attitude in the design state.

[0018] (2) This invention can measure the wheel center position / vehicle ground clearance / load under various loads of the front and rear wheels, and automatically calculate the suspension stiffness, tire stiffness and tire diameter based on these basic parameters; compare the measured parameters with the vehicle reference point and ground line, automatically calculate the wheel center deviation and vehicle ground clearance deviation, fit the actual vehicle ground line, and provide the parameters that need to be corrected for the actual vehicle or theory, so as to ensure the consistency between theory and actual vehicle; it can simulate various wheelbases and suspension hard points, and can quickly replace the target elastic component to verify the influence on attitude. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a schematic diagram of the vehicle attitude design and verification system according to one or more embodiments of the present invention; Figure 2 This is a schematic diagram of the test bench structure according to one or more embodiments of the present invention; Figure 3 This is a schematic diagram of the tooling frame installation according to one or more embodiments of the present invention; Figure 4 This is a schematic diagram of sensor installation according to one or more embodiments of the present invention; Figure 5 This is a computer-generated schematic diagram of a physical ground line according to one or more embodiments of the present invention; Figure 6 This is a graph showing the relationship between the change in shaft load and the change in spring load according to one or more embodiments of the present invention.

[0021] Among them, 1. Tooling frame, 2. Test bench, 3. Front suspension, 4. Rear suspension, 5. Position sensor, 6. Pressure sensor, 7. Computer; 101. Upper body; 102. Lower body; 103. Support column; 104. Connecting column; 201. Support plate; 202. Position signal receiver; 203. Flat plate body. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] For ease of description, the words "upper," "lower," "front," and "rear" appearing in this invention only indicate that they are consistent with the upper, lower, front, and rear directions of the accompanying drawings. They do not limit the structure and are merely for the purpose of facilitating the description of this invention and simplifying the description. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Example 1: This embodiment provides a vehicle attitude design and verification system. In the early stages of vehicle development, a test bench 2 is set up to design and measure the vehicle attitude. Figure 1 As shown, the vehicle attitude design and verification system includes a test bench 2, a tooling frame 1, a pressure sensor 6, a position sensor 5, and a computer 7. The test bench 2 is a horizontal weighbridge with vibration function, used to simulate tortuous roads to release suspension stress and measure the front and rear axle loads; the tooling frame 1 is used to provide the mounting points for the suspension.

[0025] Specifically, such as Figure 2 As shown, the test bench 2 includes a flat plate body 203 and support plates 201. The flat plate body 203 is horizontally arranged, serving as the ground in the coordinate system and used to support the vehicle. Support plates 201 are arranged parallel to the flat plate body 203 on its upper side, with the positions of the support plates 201 corresponding to the wheel positions; that is, a total of four support plates 201 are provided. The shape of the support plates 201 can be set according to actual conditions. In this embodiment, the support plates 201 are rectangular plates.

[0026] The support plate 201 is height-adjustable. Its bottom surface is connected to the plate body 203 via a lifting component located within the plate body 203. When the support plate 201 is lowered to its lowest height, it is flush with the upper surface of the plate body 203. The upper surface of the support plate 201 serves as the wheel support surface. The lifting component can be an electric push rod, a cylinder, a hydraulic cylinder, or other lifting structures. When the support plate 201 is flush with the plate body 203, it can be used to detect vehicle axle load. By raising and lowering the four support plates 201 at different frequencies, the suspension stress release can be simulated when a vehicle travels over a tortuous road. Therefore, the support plate 201 has two functions.

[0027] like Figure 1 As shown, the front suspension 3 is placed on the two support plates 201 at one end of the flat plate body 203, and the rear suspension 4 is placed on the two support plates 201 at the other end. The tooling frame 1 is set on the upper side of the front suspension 3 and the rear suspension 4, restricting the front suspension 3 and the rear suspension 4 between the tooling frame 1 and the flat plate body 203.

[0028] like Figure 3As shown, the tooling frame 1 includes an upper body 101, a lower body 102, support columns 103, and connecting columns 104. The upper body 101 and the lower body 102 are parallel to each other and are connected by multiple connecting columns 104. The structural forms of the upper body 101 and the lower body 102 can be set according to actual installation requirements. In this embodiment, in order to simplify the structure of the tooling frame 1, the upper body 101 is a rectangular plate structure, and the lower body 102 is composed of at least two crossbeams.

[0029] In use, the upper body 101 remains fixed and bears the pressure applied by the horizontal body. The lower body 102 is supported between the front suspension 3 and the rear suspension 4, providing lateral mounting points for the suspension. Connecting columns 104 are provided on the upper body 101 corresponding to the shock absorber positions of the front suspension 3 and the rear suspension 4. The bottom end of the connecting column 104 contacts the top end of the shock absorber, providing longitudinal support points for the front suspension 3 and the rear suspension 4, used in conjunction with the flat plate body 203 to apply pressure to the suspension. In this embodiment, the tooling frame 1 is designed according to the suspension hard points. The mounting points of the suspension in the tooling frame 1 are located at the designed positions in the vehicle coordinate system, and the dimensional tolerances of the suspension hard points meet the gauge accuracy.

[0030] like Figure 1 and Figure 4 As shown, a position sensor 5 is installed at the center of each wheel, and position signal receivers 202, corresponding to the position sensors 5, are installed on both sides of the flat plate body 203. The position signals detected by the position sensors 5 are transmitted to the computer 7 through the position signal receivers 202 to obtain the Z-axis coordinate of the wheel center and the height of the wheel center from the ground. Figure 1 and Figure 3 As shown, pressure sensors 6 are installed at the contact position between the connecting column 104 and the shock absorber. There are a total of four pressure sensors 6. The pressure sensors 6 detect the magnitude of the force of the spring in the shock absorber to monitor the stress state of each suspension hard point and correct the deviation of the elastic element in the theoretical design.

[0031] Input the vehicle's ground line parameters into computer 7, which will fit the actual ground line state based on the actual vehicle's performance, compare it with the theoretical ground line, and compare the differences of various parameters, thereby analyzing the causes of attitude deviation.

[0032] This embodiment designs a test bench 2 and a tooling frame 1 to rigidly connect the suspension, ensuring that the hard points are consistent with the overall vehicle condition and that loads can be applied to simulate the vehicle's load and stress conditions. It also features vibration control to fully release suspension stress. Position sensors 5 and pressure sensors 6 are installed to measure the wheel center position, vehicle ground clearance, and load under various loads on the front and rear wheels, and automatically calculate suspension stiffness, tire stiffness, and tire diameter based on these basic parameters.

[0033] Example 2: This embodiment also provides a method for designing and verifying the attitude of a vehicle, using the system described in Embodiment 1, and includes the following steps: Step 1: Fix the front suspension 3 and rear suspension 4 to the test bench 2 with bolts to ensure that the installation points of the suspension are in the designed positions in the vehicle coordinate system.

[0034] Step 2: Pre-set the oscillation frequency and amplitude, and control the four support plates 201 to oscillate up and down to ensure that the stress of the suspension (front suspension 3 and rear suspension 4) is fully released.

[0035] Step 3: After the suspension stress is released, control the wheel support surface to descend until the load on the support surface is 0. At this time, measure the height Z0 of the front wheel center and the rear wheel center from the support plate 201. Then control the wheel support surface to descend to the same height as the plate body 203, that is, the wheel support surface is flush with the upper surface of the plate body 203; move the test bench 2 upward as a whole, and monitor the front wheel axle load and the rear wheel axle load.

[0036] It should be noted that the test bench 2 can be moved upward as a whole using the supporting lifting equipment.

[0037] Step 4: Apply set loads to the front and rear wheels under different working conditions. In this embodiment, the verification is carried out under three working conditions: no load, half load, and full load.

[0038] As shown in Table 1, the main measurement parameters include front wheel load, rear wheel load, front spring load, rear spring load, front wheel center ground clearance, rear wheel center ground clearance, front wheel center coordinates, rear wheel center coordinates, front suspension stiffness 3, rear suspension stiffness 4, tire stiffness, front tire radius of force, and rear tire radius of force.

[0039] Table 1 Main Measurement Parameters

[0040] Under no-load conditions, the front wheels are loaded with no-load load to K1, and the rear wheels are loaded with no-load load to K2. The test bench 2 is locked, and the position sensor 5 detects the height Z of the front wheel center off the ground. 10 Rear wheel center ground clearance Z 20 The front spring load K detected by pressure sensor 6 10 Rear spring load K 20 .

[0041] Under half-load conditions, the front wheels are loaded with no-load at K3, and the rear wheels are loaded with no-load at K4. Test bench 2 is locked, and the position sensor 5 detects the height Z of the front wheel center off the ground. 30 Rear wheel center ground clearance Z 40 The front spring load K detected by pressure sensor 6 30 Rear spring load K 40 .

[0042] Under full load conditions, the front wheels are loaded with an unloaded load to K5, and the rear wheels are loaded with an unloaded load to K6. The test bench 2 is locked, and the position sensor 5 detects the height Z of the front wheel center off the ground. 50 Rear wheel center ground clearance Z 60 The front spring load K detected by pressure sensor 6 50 Rear spring load K 60 .

[0043] As shown in Table 1, the stiffness F1 of the front suspension 3 is: ; Among them, Z 101 Z represents the coordinates of the front wheel center under no-load conditions. 301 These are the coordinates of the front wheel center under half-load conditions.

[0044] The stiffness F2 of the rear suspension is: ; Among them, Z 201 Z represents the coordinates of the rear wheel center under no-load conditions. 401 These are the coordinates of the rear wheel center under half-load conditions.

[0045] The radius of force of the front tire under no-load conditions is The radius of the rear tire under no-load conditions is The radius of force of the front tire under half-load conditions is The radius of the rear tire under half-load conditions is The radius of force of the front tire under full load conditions is The radius of force of the rear tire under full load conditions is .

[0046] Based on the calculation results shown in Table 1, computer 7 can generate the following: Figure 5 The actual ground line shown represents the difference between the actual ground line and the theoretical ground line, i.e., the attitude difference.

[0047] This embodiment yields a key suspension design parameter—spring load—which is the most significant cause of discrepancies in ground alignment. To avoid these discrepancies, multiple sets of axle load variation versus spring load variation curves are selected using springs of different stiffnesses to generate an approximate formula to guide subsequent spring design. Figure 6 As shown, the generated approximate formula is compared with the theoretical calculation formula, and a correction amount is added for the later design of the spring load.

[0048] Since the difference in Z-axis attitude is actually a difference in ground line, the attitude problem can be transformed into a ground line accuracy problem. In this embodiment, the suspension stress is first released through vibration, and then the vehicle loading is simulated. The wheel center coordinates, wheel center ground clearance, and load conditions at various points are tested under different loads. Through calculation and transformation, the fitted ground line is compared with the theoretical ground line, the differences are analyzed, and anomalies are identified. Based on this, it is determined whether to modify the ground line or the suspension elastic components.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A vehicle attitude design and verification system, characterized in that, Includes a test bench, tooling frame, pressure sensor, and position sensor; The test bench is equipped with multiple support plates for supporting the wheels. The support plates have a lifting function. By raising and lowering the multiple support plates at different frequencies, the stress of the suspension is released by simulating the vehicle passing over a tortuous road. The tooling frame is set on the upper side of the test bench and is used to provide the mounting points for the suspension. The suspension is rigidly connected, and the mounting point of the suspension in the tooling frame is located at the designed position in the vehicle coordinate system. The pressure sensor is installed at the contact position between the tooling frame and the suspension to detect the pressure on the springs in the suspension; the position sensor is used to detect the wheel center coordinates and the wheel center height above the ground. The test bench includes a horizontally arranged flat plate body, which is connected to four liftable support plates; the support plates are parallel to the flat plate body and are also used to detect vehicle load. The tooling frame includes an upper body and a lower body, which are connected by multiple connecting columns; the bottom of the upper body is connected to multiple support columns, which are used to apply pressure to the suspension.

2. The vehicle attitude design and verification system according to claim 1, characterized in that, The outer side of the flat plate is equipped with position signal receivers that correspond one-to-one with the support plate. The signal receivers are used to receive the detection signals from the position sensors to obtain the Z-axis coordinate of the wheel center and the height of the wheel center above the ground.

3. The vehicle attitude design and verification system according to claim 1, characterized in that, It also includes a computer used to fit the actual ground line state based on the vehicle's ground line parameters.

4. A method for designing and verifying the attitude of a vehicle, characterized in that, The system described in any one of claims 1-3 includes: The suspension stress is released by the up-and-down oscillation based on the four support plates. The support plate is lowered until the load on its support surface is 0, and the height Z0 of the front and rear wheel centers from the support plate is detected; then the support plate is lowered to the same height as the plate body. The test bench moves upward as a whole and monitors the axle loads of the front and rear wheels; under different working conditions, set loads are applied to the front and rear wheels, and the Z-axis coordinate of the wheel center, the height of the wheel center off the ground, and the spring loads of the front and rear wheels are detected; Based on the acquired measurement data, a physical ground line is generated and compared with the theoretical ground line to obtain key parameters for suspension design.

5. The method for designing and verifying the attitude of a vehicle according to claim 4, characterized in that, The different operating conditions include three conditions: no load, half load, and full load. In the unloaded condition, the front wheels are loaded with an unloaded load at K1, and the rear wheels are loaded with an unloaded load at K2. In the half-load condition, the front wheels are loaded with half load at K3, and the rear wheels are loaded with half load at K4; Under the full load condition, the front wheels are fully loaded to K5, and the rear wheels are fully loaded to K6.

6. The method for designing and verifying the attitude of a vehicle according to claim 4, characterized in that, By selecting springs with different stiffnesses and selecting multiple sets of curves showing the relationship between shaft load variation and spring load variation, an approximate formula is generated.

7. The method for designing and verifying the attitude of a vehicle according to claim 6, characterized in that, The approximate formula is compared with the theoretical calculation formula, and a correction amount is added.

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