Vehicle weighing system and method of weighing

Abstract

The present application relates to the field of vehicle engineering and metrology, in particular to a vehicle weighing system and a weighing method. The system comprises a front axle weighing system, a rear axle weighing system and a data processing unit. The front axle weighing system integrates a weighing sensor between the steering knuckle and the thrust bearing, and the front axle pipe, and the kingpin passes through the sensor, so that the real vertical load received by the front axle can be directly measured. The system combines the height sensors of the front and rear axles to estimate the load by detecting the suspension deformation. The data processing unit fuses the directly measured weight data and the load data estimated based on the height to calculate the overall vehicle weight, and uses the directly measured weight data to self-calibrate and correct the suspension height drift caused by leaf spring fatigue and the like. The present application solves the problem of precision decline caused by pure reliance on strain gauge drift and pure reliance on suspension height affected by fatigue in the prior art, significantly improving the long-term reliability and accuracy of vehicle weighing data.

Description

Technical Field

[0001] This invention relates to the fields of vehicle engineering and metrology, specifically to a vehicle weighing system and weighing method. Background Technology

[0002] For understanding the technical content of this invention:

[0003] With the development of logistics and commercial vehicle technology, obtaining reliable vehicle load information in real time has become a key factor affecting vehicle control strategies, safety redundancy design, and overall vehicle energy consumption optimization.

[0004] Existing mainstream vehicle weighing solutions are mainly divided into two categories: The first type involves installing strain gauges on load-bearing components to obtain load information through the linear relationship between strain and load. However, as the vehicle's service life increases, the structural components undergo plastic deformation or aging, leading to zero-point drift, introducing increasingly larger deformation errors, and making it difficult to maintain accuracy over a long period.

[0005] The second method involves measuring the deformation of the suspension system and calculating the weight based on the suspension stiffness. While this approach is less expensive, it heavily relies on the stability of the suspension stiffness. Over long-term use, load-bearing components such as leaf springs can experience fatigue deformation, causing the height sensor to register compression signals even when unloaded, thus misinterpreting the situation as a load.

[0006] Relevant patent documents retrieved: This document, published in China (CN104568096A), discloses a method for measuring vehicle weight based on front and rear axle height sensors and leaf spring stiffness functions. It estimates the load using static suspension stiffness by measuring changes in front and rear axle height, and then adds this to the vehicle's curb weight to obtain the total weight.

[0007] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: While the aforementioned patent incorporates front and rear axle height sensors, it neglects the stiffness changes and reference height drift caused by suspension fatigue deformation over long-term use. The document lacks any real-time correction or long-term stability guarantee mechanism, failing to compensate for the cumulative error caused by suspension drop. Furthermore, it only measures "load change" rather than the actual axle load, unable to distinguish between height changes due to load and those due to suspension fatigue. In addition, this solution is insensitive to vehicle attitude; on non-level roads, height differences will be misinterpreted by the system as load changes, further reducing accuracy.

[0008] Therefore, there is an urgent need for a vehicle weighing system that can directly measure the actual load and use the actual load to make real-time corrections to the suspension height measurement system, in order to solve the problem of accuracy decay during long-term use. Summary of the Invention

[0009] In order to solve at least one of the above-mentioned technical problems existing in the prior art, the present invention provides a vehicle weighing system.

[0010] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a vehicle weighing system, comprising: a front axle weighing system, a rear axle weighing system, and a data processing unit; The front axle weighing system is configured to detect the direct load weight of the front axle and the change in the height of the front axle suspension. The rear axle weighing system is configured to detect changes in the height of the rear axle suspension. The data processing unit is connected to the front axle weighing system and the rear axle weighing system respectively, and is used to receive detection data and calculate the vehicle load. The front axle weighing system includes a front axle tube, a steering knuckle disposed at both ends of the front axle tube, a thrust bearing, and a weighing sensor. The load cell is a pressure sensing device. The front axle tube end, the load cell, the thrust bearing and the steering knuckle are connected in series by the kingpin, so that the vertical load acting on the front axle is transmitted through the load cell. The weighing sensor is installed between the steering knuckle and the thrust bearing; or between the thrust bearing and the end of the front axle tube.

[0011] Furthermore, the load cell includes an upper surface and a lower surface, and a shaft hole is provided in the middle of the load cell for the main pin to pass through; When the load cell is installed between the steering knuckle and the thrust bearing, the lower surface of the load cell is fixedly mounted on the load-bearing surface of the steering knuckle.

[0012] Furthermore, the front axle weighing system also includes a left front axle height sensor and a right front axle height sensor; The rear axle weighing system includes a rear axle tube, a rear axle right-side height sensor, and a rear axle left-side height sensor. The sensing modules of the front axle left height sensor, the front axle right height sensor, the rear axle right height sensor, and the rear axle left height sensor are fixed to the vehicle frame end. The base plates of the left and right front axle height sensors are fixed to the front axle tube. The base plates of the rear axle right-side height sensor and the rear axle left-side height sensor are fixed to the rear axle tube; The sensing module is connected to the base plate via a linkage mechanism to detect the sway angle generated by suspension compression.

[0013] Secondly, the present invention also provides a weighing method for a vehicle weighing system, comprising the following steps: S1. Obtain the first front wheel end vertical load directly measured by the load cell in the front axle weighing system. Vertical load on the second front wheel end ; S2. Obtain the height change detected by the front axle left height sensor and the front axle right height sensor, and calculate the first front wheel end estimated load G3 and the second front wheel end estimated load G4 in combination with the front suspension stiffness k1. S3. Obtain the height change detected by the rear axle left height sensor and the rear axle right height sensor, and calculate the first rear wheel end estimated load G5 and the second rear wheel end estimated load G6 in combination with the rear suspension stiffness k2. S4. The data processing unit obtains the vehicle load capacity through fusion calculation. The calculation formula is:

[0014] Furthermore, the method also includes a correction step for suspension fatigue deformation: S5. Determine if the vehicle is on a level surface; S6. When the vehicle is on a level road and in an unloaded state or a specific calibration state, obtain the current height value output by the height sensor of the current front axle weighing system and compare it with the preset initial height value. S7, based on front suspension stiffness or rear suspension stiffness Calculate the load correction amount caused by suspension fatigue deformation at each location. ; S8. Utilizing the aforementioned load correction amount Regarding the vehicle's load capacity Make corrections.

[0015] Furthermore, the load correction amount in step S8 The calculation formulas include:

[0016]

[0017]

[0018]

[0019] in, These are the initial height values ​​for each location. This represents the current height value of each location after changing over time; Corrected vehicle load capacity The calculation formula is:

[0020] Furthermore, step S5, which determines whether the vehicle is on a level road surface, includes: detecting the height signals output by the four height sensors: the left front axle height sensor, the right front axle height sensor, the left rear axle height sensor, and the right rear axle height sensor. If the height difference between the four height signals does not exceed a preset threshold m, then the vehicle is determined to be on a level road surface.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The front axle load cell of this invention is integrated between the kingpin and the steering knuckle, providing a simple and direct force model that does not interfere with steering motion. Using the front axle load cell as a reference ensures high measurement accuracy and is less susceptible to large deformations of structural components. The fatigue correction amount of the leaf spring can be calculated at any time, solving the problem of inaccurate weighing after vehicle aging. Furthermore, it employs a fusion of direct weighing and indirect calculation for mutual verification. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the vehicle weighing system in an embodiment of the present invention; Figure 2 This is an exploded view of the front axle weighing system in an embodiment of the present invention; Figure 3 This is a schematic diagram showing the installation details of the weighing sensor in an embodiment of the present invention; Figure 4 This is a schematic diagram of the height sensor in an embodiment of the present invention; Figure 5 This is an exploded view of the rear axle weighing system in an embodiment of the present invention; Figure label: 1. Front axle weighing system; 2. Rear axle weighing system; 3. Front axle tube; 4. Front axle left side height sensor; 5. Front axle right side height sensor; 6. Right side weighing sensor; 7. Left side weighing sensor; 8. Right side leaf spring seat; 9. Left side leaf spring seat; 10. Sensing module; 11. Base plate; 12. Connecting rod one; 13. Connecting rod two; 14. Right side steering knuckle; 15. Left side steering knuckle; 18. Lower end face of pressure sensing device; 19. Shaft hole; 23. Thrust bearing; 24. Rear axle tube; 25. Rear axle left side height sensor; 26. Rear axle right side height sensor. Detailed Implementation

[0023] The technical solution of the present invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0024] It should be noted that, unless otherwise specifically stated, the relative arrangement and numerical expressions of the components and steps described in these embodiments should not be construed as limiting the scope of the invention.

[0025] The following description of exemplary embodiments is merely illustrative and is not intended to limit the invention or its application or use in any way. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail herein, but where applicable, such techniques, methods, and apparatus should be considered part of this specification.

[0026] Example 1 The vehicle weighing system of the present invention mainly consists of three parts: a front axle weighing system 1, a rear axle weighing system 2, and a data processing unit.

[0027] The front axle weighing system 1 includes a front axle tube 3, a left front axle height sensor 4, a right front axle height sensor 5, a right-side weighing sensor 6, a left-side weighing sensor 7, a right-side steering knuckle 14, a left-side steering knuckle 15, a right-side leaf spring seat 8, a left-side leaf spring seat 9, and a thrust bearing 23. The right-side and left-side leaf spring seats 8 and 9 are welded to the front axle tube 3 to support the weight of the vehicle body. The left and right ends of the front axle tube 3 are connected in series with the right-side weighing sensor 6, the left-side weighing sensor 7, the right-side steering knuckle 14, the left-side steering knuckle 15, and the thrust bearing 23 via kingpins.

[0028] Taking the left side as an example, the left end of the front axle tube 3, the left steering knuckle 15, the left load cell 7, and the thrust bearing 23 are connected together by a kingpin. When the vehicle is loaded, the gravity acting on the left leaf spring seat 9 is transmitted vertically to the thrust bearing 23 through the left end of the front axle tube 3, then directly to the left load cell 7, and finally to the left steering knuckle 15 and the wheel. The left end weight G1 can be obtained through the left load cell 7, and similarly, the right end weight G2 can be obtained through the right load cell 6.

[0029] The right-side load cell 6 and the left-side load cell 7 are designed as pressure sensing devices with a central hole. The lower end face 18 of the pressure sensing device is fixedly mounted on the load-bearing surfaces of the right-side steering knuckle 14 and the left-side steering knuckle 15 by bolts. A shaft hole 19 is provided between the right-side load cell 6 and the left-side load cell 7, through which the kingpin passes, ensuring that the sensor is located at the center of force and does not interfere with steering movement. The right-side load cell 6 and the left-side load cell 7 output the detected weight signal via a signal line.

[0030] The sensing modules 10 of the front axle left height sensor 4 and the front axle right height sensor 5 are fixed to the vehicle frame end, and the base plate 11 is welded to the front axle tube 3. The sensing module 10 and the base plate 11 are connected by a linkage mechanism consisting of a first linkage 12 and a second linkage 13. When the suspension is compressed, the front axle tube 3 moves relative to the vehicle frame, causing the first linkage 12 to swing, and the sensing module 10 outputs the swing angle A of the first linkage 12.

[0031] The rear axle weighing system consists of a rear axle tube 24, a rear axle right-side height sensor 25, and a rear axle left-side height sensor 26. Its installation method is similar to that of the front axle, and it is used to detect the deformation of the rear suspension.

[0032] To clearly describe the calculation logic of this invention, the load variables output by each sensor are defined as follows: G1: The vertical load on the left front wheel end, directly measured by the left-side weighing sensor 7, is the actual physical value.

[0033] G2: The vertical load on the right front wheel end, directly measured by the right-side weighing sensor 6, is the actual physical value.

[0034] G3: Height change based on height sensor 4 on the left side of the front axle. Combined with front suspension stiffness The estimated load on the left front wheel end was calculated.

[0035] G4: Height change based on height sensor 5 on the right side of the front axle. Combined with front suspension stiffness The estimated load on the right front wheel end was calculated.

[0036] G5: Height change based on height measurement by rear axle right-side height sensor 25 Combined with rear suspension stiffness The calculated estimated load on the right rear wheel end.

[0037] G6: Height change based on height measurement by rear axle left-side height sensor 26 Combined with rear suspension stiffness The estimated load at the left rear wheel end was calculated.

[0038] (the above) All are changes relative to the no-load calibration zero point, expressed through the link length. With angle change The calculation shows that, ) The left-side height sensor 4 and the right-side height sensor 5 of the front axle output angles respectively. and .pass and The change in quantity and the length of the connecting rod The height change of the front axle can be calculated. and Based on the stiffness of the front suspension The load capacity that causes the height change can be calculated:

[0039]

[0040] The rear axle weighing system consists of a rear axle tube 24, a right rear axle height sensor 25, and a left rear axle height sensor 26. The output angle changes of the right rear axle height sensor 25 and the left rear axle height sensor 26 are as follows: and Through the length of the link Calculation of height change , Based on the stiffness of the rear suspension The load capacity that causes the height change can be calculated:

[0041]

[0042] The data processing unit receives weighing sensor data from the front axle weighing system. Altitude sensor information and height sensor information of the rear axle weighing system The vehicle's load capacity is calculated through fusion. :

[0043] In this formula, the front axle section uses data directly measured by a load cell. Data indirectly estimated by altitude sensors The average value is used to smooth out random errors.

[0044] Over time, load-bearing components, such as leaf springs, will gradually fatigue and deform. For example, when a new car leaves the factory, the output height of the front axle weighing system under no-load conditions is... and After a period of time, due to leaf spring collapse, the height read by the front axle height sensor may change even when not loaded. and (generally This manifests as the suspension being compressed. At this point, the height sensor may incorrectly calculate a false load.

[0045] This system utilizes the weight output from the weighing sensor. and The correction is then made to obtain the corrected amount. Because and It measures force directly and is unaffected by leaf spring deformation. When the system detects... and It shows as unloaded or with unchanged load, but When the value changes, calculate the correction amount:

[0046]

[0047] Similarly, for the rear axle, although there is no direct load cell, corrections can be made based on the overall vehicle attitude or by assuming similar fatigue decay characteristics:

[0048]

[0049] Thus, the corrected accurate load capacity is obtained:

[0050] The corrected calculation assumes the vehicle is on a level surface. Whether the surface is level can be determined using information from four height sensors: if the height difference between the four sensor signals does not exceed a certain threshold... If the road surface is considered level, then the above-mentioned correction calculation can be performed. Height difference. This can be determined through calibration to eliminate normal system gaps and signal errors.

[0051] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A vehicle weighing system, characterized in that, include: Front axle weighing system, rear axle weighing system, and data processing unit; The front axle weighing system is configured to detect the direct load weight of the front axle and the change in the height of the front axle suspension. The rear axle weighing system is configured to detect changes in the height of the rear axle suspension. The data processing unit is connected to the front axle weighing system and the rear axle weighing system respectively, and is used to receive detection data and calculate the vehicle load. The front axle weighing system includes a front axle tube, a steering knuckle disposed at both ends of the front axle tube, a thrust bearing, and a weighing sensor. The load cell is a pressure sensing device. The front axle tube end, the load cell, the thrust bearing and the steering knuckle are connected in series by the kingpin, so that the vertical load acting on the front axle is transmitted through the load cell. The weighing sensor is installed between the steering knuckle and the thrust bearing; or between the thrust bearing and the end of the front axle tube.

2. The vehicle weighing system according to claim 1, characterized in that: The load cell includes an upper surface and a lower surface, and a shaft hole is provided in the middle of the load cell for the main pin to pass through; When the load cell is installed between the steering knuckle and the thrust bearing, the lower surface of the load cell is fixedly mounted on the load-bearing surface of the steering knuckle.

3. The vehicle weighing system according to claim 1, characterized in that: The front axle weighing system also includes a front axle left-side height sensor and a front axle right-side height sensor; The rear axle weighing system includes a rear axle tube, a rear axle right-side height sensor, and a rear axle left-side height sensor. The sensing modules of the front axle left height sensor, the front axle right height sensor, the rear axle right height sensor, and the rear axle left height sensor are fixed to the vehicle frame end. The base plates of the left and right front axle height sensors are fixed to the front axle tube. The base plates of the rear axle right-side height sensor and the rear axle left-side height sensor are fixed to the rear axle tube; The sensing module is connected to the base plate via a linkage mechanism to detect the sway angle generated by suspension compression.

4. A weighing method using the vehicle weighing system as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1. Obtain the first front wheel end vertical load directly measured by the load cell in the front axle weighing system. Vertical load on the second front wheel end ; S2. Obtain the height change detected by the left and right front axle height sensors, and combine it with the front suspension stiffness. The estimated load at the first front wheel end was calculated. Estimated load at the second front wheel end ; S3. Obtain the height change detected by the left rear axle height sensor and the right rear axle height sensor, and combine it with the rear suspension stiffness. The estimated load at the first rear wheel end was calculated. Estimated load at the second rear wheel end ; S4. The data processing unit obtains the vehicle load capacity through fusion calculation. The calculation formula is: .

5. The vehicle weighing method according to claim 4, characterized in that: The method also includes a correction step for suspension fatigue deformation: S5. Determine if the vehicle is on a level surface; S6. When the vehicle is on a level road and in an unloaded state or a specific calibration state, obtain the current height value output by the height sensor of the current front axle weighing system and compare it with the preset initial height value. S7, based on front suspension stiffness or rear suspension stiffness Calculate the load correction amount caused by suspension fatigue deformation at each location. ; S8. Utilizing the aforementioned load correction amount Regarding the vehicle's load capacity Make corrections.

6. The vehicle weighing method according to claim 5, characterized in that: Load correction amount in step S8 Calculation formula include: in, These are the initial height values ​​for each location. This represents the current height value of each location after changing over time; Corrected vehicle load capacity The calculation formula is: 。 7. The vehicle weighing method according to claim 5, characterized in that: Step S5, determining whether the vehicle is on a level road surface, includes: detecting the height signals output by the four height sensors: the left front axle height sensor, the right front axle height sensor, the left rear axle height sensor, and the right rear axle height sensor. If the height difference between the four height signals does not exceed a preset threshold... If so, the vehicle is determined to be on a level road surface.

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