Dynamic vehicle roof deformation measuring method based on linear potentiometer
By using dynamic roof deformation measurement methods based on line potentiometers in vehicles, the problem that the prior art cannot effectively evaluate the roof deformation in vehicle rolling accidents is solved, high-precision and low-cost roof deformation measurement is achieved, and the ability to evaluate the safety performance of vehicle rolling is enhanced.
Patent Information
- Application Number
- CN202510151286.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-05-06
AI Technical Summary
The existing rolling and collision regulations mainly focus on static or quasi-static roof compression tests, which cannot fully reflect the dynamic characteristics and complex mechanical behavior of rolling and collisions. There is a lack of effective methods to record the roof deformation in real time, making it difficult to accurately evaluate the overall safety performance of the vehicle in rolling accidents.
A dynamic vehicle roof deformation measurement method based on a linear potentiometer is adopted. By selecting a lifting ring on the roof with a potentially large deformation area, and fixing a linear potentiometer on the vehicle floor, data is collected synchronously in real time, the spatial position coordinates of the point to be measured are calculated, the deformation amount of the roof is calculated, and it is converted to the body coordinate system.
It realizes a comprehensive and accurate reflection of the roof deformation of the vehicle in a rolling accident, improves the accuracy and versatility of measurement, reduces operational complexity and cost, and can better evaluate the rolling safety performance of the vehicle.
Smart Images
Figure CN119934955A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of vehicle safety testing, and in particular to a method for measuring dynamic vehicle roof deformation based on a linear potentiometer. Background Art
[0002] In traffic accidents, although the probability of rollover accidents is relatively low, the harm they cause is extremely serious. During the rollover process, the top and sides of the vehicle are subjected to huge impact forces, causing the roof to collapse and the passenger compartment to be severely deformed, greatly compressing the living space of the occupants and increasing the risk of fatal injuries. Especially when the accident occurs at high speeds and complex road conditions, rollover accidents are more likely to cause occupants to be thrown out of the vehicle, causing more serious injuries. Therefore, in-depth research on the safety of rollover accidents, strengthening vehicle structural design to enhance occupant protection measures, and improving relevant test regulations are of great significance to significantly reduce the casualty rate of rollover accidents.
[0003] However, in the existing rollover collision regulations, the main focus is on static or quasi-static roof compression tests. Although the compression performance of the roof can be evaluated to a certain extent, it cannot fully reflect the dynamic characteristics of the rollover collision, nor can it simulate the complex mechanical behavior and dynamic response of the occupants in a real rollover accident. Therefore, it is difficult to accurately evaluate the overall safety performance of the vehicle in a rollover accident based solely on the results of static or quasi-static tests.
[0004] The few dynamic rollover tests currently only focus on the deployment of airbags and air curtains, and lack an effective method to record the roof deformation in real time. As one of the key indicators for assessing the risk of occupant injury and the size of the survival space in a rollover accident, accurate measurement of the roof deformation is crucial for a comprehensive assessment of the vehicle's rollover safety performance.
[0005] At present, although some deformation measurement methods based on sensor technology have been applied in the field of vehicle engineering, most of these methods have problems such as complex operation, high cost or insufficient measurement accuracy. In particular, the existing technology still faces many challenges in achieving multi-point measurement and real-time data collection. Therefore, there is an urgent need for a dynamic vehicle roof deformation measurement method that is simple to operate, low cost and has high measurement accuracy to comprehensively and accurately evaluate the safety performance of the vehicle in a rollover accident. Summary of the invention
[0006] The purpose of the present invention is to propose a dynamic vehicle roof deformation measurement method based on a linear potentiometer, and the technical solution can fully and accurately reflect the roof deformation of the vehicle in a rollover accident.
[0007] To achieve the above object, the present invention provides a method for measuring dynamic vehicle roof deformation based on a linear potentiometer, comprising: Select an area between the A-pillar and the B-pillar on the roof where large deformation may occur as the test point and install a lifting ring at the test point to ensure that the lifting ring is rigidly connected to the roof; select three points on the vehicle floor that are on the same horizontal plane and have a certain interval, fix the wire potentiometer and adjust the sensor direction, and fix the free end of the wire potentiometer to the lifting ring of the test point at the same time; measure the length of each potentiometer wire and the distance between the bottom plate fixing point; Select the outlet of any linear potentiometer as the coordinate origin and establish the coordinate system; The data of all the linear potentiometers are collected synchronously in real time; the spatial position coordinates of the test point at each time step are calculated based on the real-time collected data of the linear potentiometers; the deformation of the roof during the rolling process is calculated based on the spatial position coordinates of the test point; the calculated deformation of the roof is converted from the linear potentiometer coordinate system to the vehicle body coordinate system.
[0008] Beneficial effects of the basic solution: Select the area between the A-pillar and the B-pillar on the roof where large deformation may occur as the test point, and install the lifting ring to ensure that the lifting ring is rigidly connected to the roof. This installation method is relatively simple and can effectively transfer the deformation of the roof to the lifting ring. At the same time, it is also convenient to fix the wire potentiometer on the vehicle floor, and by adjusting the sensor direction and fixing the free end of the pull wire, the installation process of the entire measuring device can be easy to operate, without the need for complex equipment and processes, and easy to implement in actual application scenarios.
[0009] By selecting three points with a certain interval on the vehicle floor to fix the linear potentiometer, and fixing its pull wire to the lifting ring of the measured point on the roof, multi-point measurement is achieved. Compared with single-point measurement, this method can obtain the position information of the measured point more comprehensively and accurately. The three linear potentiometers can monitor the motion trajectory of the measured point during the roof deformation process from different angles and positions, and convert the calculated roof deformation from the linear potentiometer coordinate system to the vehicle body coordinate system, which can restore the three-dimensional space trajectory, thereby effectively reducing the measurement error and improving the measurement accuracy.
[0010] Compared with other complex deformation measurement methods (such as laser scanning, 3D reconstruction, etc.), the equipment and operation required for this method are relatively simple and the cost is low. At the same time, since the linear potentiometer has high reliability and stability, this method can also maintain a good cost-effectiveness in long-term monitoring and frequent use. Through coordinate transformation, the deformation of the roof can be easily considered in combination with the deformation, displacement and other information of other parts of the body, which enhances the versatility of this measurement method in the field of vehicle engineering.
[0011] As an implementable preferred solution, the point to be measured is located in the center of the roof or close to the passenger compartment, and the metal hanging ring is fixed to the roof with bolts.
[0012] As an implementable preferred solution, select the outlet of any linear potentiometer as the coordinate origin and establish a coordinate system, including the following contents: Select the outlet of any linear potentiometer as the coordinate origin, and its position is (0,0,0); point the outlet of another linear potentiometer to the coordinate origin, and define this direction as the positive direction of the x-axis; measure the distance between the two as d, so the spatial position of the second outlet is (d,0,0); since the three potentiometer outlets are in the same horizontal plane when installed, measure the distance of the third potentiometer outlet relative to the origin in the x direction as m, and the distance in the y direction as n, and its spatial position is (m,n,0); according to the right-hand rule, determine the direction of the z-axis, the z-axis is perpendicular to the bottom plate plane and upward, and the initial height is the distance from the roof to the bottom plate.
[0013] As an implementable preferred solution, three test points are located on the driver's seat, the front passenger seat, and the floor below the second row of seats, forming a triangular layout.
[0014] As an implementable preferred solution, the roof is slightly vibrated to observe whether the output signal of the potentiometer changes synchronously to ensure that the installation is stable.
[0015] As an implementable preferred solution, the calculation formula for the spatial position coordinates of the point to be measured at each time step is as follows:
[0016] in, , , is the distance between the outlets of the linear potentiometer; , , It is the wire pulling degree of the wire potentiometer; Obtain the spatial position coordinates x, y and z of the point to be measured at any time:
[0017] Among them, the z coordinate values in the calculation results are both positive and negative, and the positive z position is selected to represent the point above the vehicle floor.
[0018] As an implementable preferred solution, the deformation calculation formula during the rolling process is as follows:
[0019]
[0020]
[0021] in, are the spatial position coordinates of the test point in the initial state of the vehicle, are the spatial position coordinates of the test point during the rolling process of the vehicle, and are the deformations of the roof in the x, y, and z directions, respectively.
[0022] As an implementable preferred solution, the coordinate system conversion formula is as follows:
[0023]
[0024] in, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system on the xy plane, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system in the xyz space, and the deformation of the roof in the vehicle body coordinate system is obtained. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 A logic diagram of a dynamic vehicle roof deformation measurement method based on a linear potentiometer.
[0026] Figure 2 This is the installation diagram of the wire potentiometer.
[0027] Figure 3 Create a schematic diagram for the coordinate system. DETAILED DESCRIPTION
[0028] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only partial embodiments of the present invention, which are only used to explain the present application, rather than to limit the present application. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered isolated, and they can be combined with each other to achieve better technical effects. The same reference numerals appearing in the drawings of the following embodiments represent the same features or components, which can be applied to different embodiments.
[0029] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should have the common meanings understood by those skilled in the art in the art to which the present invention belongs.
[0030] The present invention is further described in detail below in conjunction with the accompanying drawings: Reference Figure 1 , a method for measuring dynamic vehicle roof deformation based on a linear potentiometer, comprising: Step S100, hardware installation, includes: Step S101, select the area between the A-pillar and the B-pillar on the roof where large deformation may occur during the rollover process as the test point (e.g., the center of the roof or a position close to the passenger compartment). Install a metal ring at the test point and fix it with bolts to ensure that the ring is rigidly connected to the roof to avoid looseness. If multiple points are required for measurement, repeat the above steps to install rings in different areas of the roof.
[0031] Step S102, select three points on the vehicle floor that are on the same horizontal plane and have a certain interval. Figure 2 For example, the driver's seat, the front passenger seat, and the floor under the second row of seats form a triangular layout.
[0032] Use bolts to fix the wire potentiometer at each point to adjust the sensor direction, ensure that the wire outlet faces the lifting ring of the test point, and the wire outlets of the three sensors are at the same level. Fix the free ends of the wires of the three potentiometers to the lifting ring of the test point at the same time, ensure that the wires are not entangled and are perpendicular to the bottom plate plane, and ensure that the tension of the wires is appropriate to avoid over-tightening or over-loosening that affects the measurement results.
[0033] Step S103, installation verification, when the vehicle is stationary, measure the length of each potentiometer cable (r1, r2, r3) and the distance between the bottom plate fixing point (d, m, n), and record the initial value. Slightly vibrate the roof to observe whether the potentiometer output signal changes synchronously to ensure a stable installation.
[0034] Step S200, establish a coordinate system, refer to Figure 3 , select the outlet of any linear potentiometer as the origin of the coordinate system, and its position is (0,0,0). Point the outlet of another linear potentiometer to the origin of the coordinate system, and define this direction as the positive direction of the x-axis. The distance between the two is measured as d, so the spatial position of the second outlet is (d,0,0). Since the three potentiometer outlets are on the same horizontal plane when installed, the distance of the third potentiometer outlet relative to the origin in the x direction is m, and the distance in the y direction is n, and its spatial position is (m,n,0). According to the right-hand rule, determine the direction of the z-axis. The z-axis is perpendicular to the bottom plate plane and points upward. The initial height is the distance from the roof to the bottom plate.
[0035] Step S300, data acquisition and synchronization, before the vehicle rollover test begins, start the data acquisition system to ensure that it can sample at a rate of 20kHz. The data acquisition system should be able to record the data of the line potentiometer in real time and store it in a storage device.
[0036] During the data acquisition process, the data acquisition of the three linear potentiometers should be synchronized. The synchronization of the data can be ensured by setting a synchronization signal or using synchronous acquisition technology. The synchronization error should be controlled within the allowable range to ensure the accuracy of the measurement results.
[0037] Step S400, data processing and deformation calculation, includes: Step S401, calculate the spatial position of the point to be measured: calculate the spatial position coordinates of the point to be measured at each time step according to the real-time collected data of the linear potentiometer, and the calculation formula is as follows:
[0038] in, , , It is the distance between the outlets of the wire potentiometer, which is measured before the collision test; , , It is the pulling degree of the wire potentiometer and the real-time acquisition and determination of the wire potentiometer.
[0039] Then the spatial position coordinates x, y and z of the point to be measured at any time are obtained:
[0040] Among them, the z coordinate values in the calculation results are both positive and negative, and the positive z position is selected to represent the point above the vehicle floor.
[0041] Step S402, based on the spatial position coordinates of the points to be measured, calculate the deformation of the roof during the rolling process (expressed by the change of the spatial position coordinates of the points to be measured at different time steps), and the specific calculation formula is as follows:
[0042]
[0043]
[0044] in, are the spatial position coordinates of the test point in the initial state of the vehicle, are the spatial position coordinates of the test point during the rolling process of the vehicle, and are the deformations of the roof in the x, y, and z directions, respectively.
[0045] Step S403, coordinate system conversion, converting the calculated roof deformation from the linear potentiometer coordinate system to the vehicle body coordinate system, the calculation formula is as follows:
[0046]
[0047] in, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system on the xy plane, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system in the xyz space. Through the coordinate system conversion, the deformation of the roof in the vehicle body coordinate system is obtained.
[0048] The calculated roof deformation is analyzed to evaluate the roof deformation during the rollover process. The analysis includes the size, distribution, and change trend of the roof deformation. Through the result analysis, the stress and deformation law of the vehicle roof during the rollover process can be understood, providing a basis for the improvement of vehicle structure design and occupant protection measures.
[0049] The above contents are only embodiments of the present invention. The common sense such as the known specific structures and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field to which the invention belongs before the application date or the priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to explain the content of the claims.
Claims
1. A method for measuring dynamic vehicle roof deformation based on a linear potentiometer, characterized in that: include: Select an area between the A-pillar and the B-pillar on the roof where large deformation may occur as the test point and install a lifting ring at the test point to ensure that the lifting ring is rigidly connected to the roof; select three points on the vehicle floor that are on the same horizontal plane and have a certain interval, fix the wire potentiometer and adjust the sensor direction, and fix the free end of the wire potentiometer to the lifting ring of the test point at the same time; measure the length of each potentiometer wire and the distance between the bottom plate fixing point; Select the outlet of any linear potentiometer as the coordinate origin and establish the coordinate system; Real-time and synchronous data collection of all line potentiometers; According to the real-time data collected by the linear potentiometer, the spatial position coordinates of the measured point at each time step are calculated; according to the spatial position coordinates of the measured point, the deformation of the roof during the rolling process is calculated; and the calculated deformation of the roof is converted from the linear potentiometer coordinate system to the vehicle body coordinate system.
2. A method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: The point to be tested is located at the center of the roof or close to the passenger compartment, and a metal hanging ring is fixed to the roof with bolts.
3. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: Select the outlet of any linear potentiometer as the coordinate origin and establish a coordinate system, including the following: Select the outlet of any linear potentiometer as the coordinate origin, and its position is (0,0,0); point the outlet of another linear potentiometer to the coordinate origin, and define this direction as the positive direction of the x-axis; measure the distance between the two as d, so the spatial position of the second outlet is (d,0,0); since the three potentiometer outlets are in the same horizontal plane when installed, measure the distance of the third potentiometer outlet relative to the origin in the x direction as m, and the distance in the y direction as n, and its spatial position is (m,n,0); according to the right-hand rule, determine the direction of the z-axis, the z-axis is perpendicular to the bottom plate plane and upward, and the initial height is the distance from the roof to the bottom plate.
4. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: The three test points are located on the driver's seat, the front passenger seat, and the floor under the second row of seats, forming a triangular layout.
5. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 4, characterized in that: By slightly vibrating the roof, observe whether the potentiometer output signals change synchronously to ensure that the installation is stable.
6. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: The calculation formula for the spatial position coordinates of the measured point at each time step is as follows: in, , , is the distance between the outlets of the linear potentiometer; , , It is the wire pulling degree of the wire potentiometer; Obtain the spatial position coordinates x, y and z of the point to be measured at any time: Among them, the z coordinate values in the calculation results are both positive and negative, and the positive z position is selected to represent the point above the vehicle floor.
7. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: The calculation formula of deformation during rolling is as follows: in, are the spatial position coordinates of the test point in the initial state of the vehicle, are the spatial position coordinates of the test point during the rolling process of the vehicle, and are the deformations of the roof in the x, y, and z directions, respectively.
8. The method for measuring dynamic vehicle roof deformation based on a linear potentiometer according to claim 1, characterized in that: Coordinate system conversion, the formula is as follows: in, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system on the xy plane, is the deflection angle between the linear potentiometer coordinate system and the vehicle body coordinate system in the xyz space, and the deformation of the roof in the vehicle body coordinate system is obtained.