A new energy vehicle extreme working condition collision safety test method

Abstract

The application relates to the technical field of automobile testing, and discloses a new energy automobile limit working condition collision safety test method, which comprises the following steps: performing a bottom scraping test, controlling a vehicle to pass through a water area at a preset speed and collide with an obstacle, monitoring battery state parameters, and determining battery safety performance; performing front and rear pinch collision test, making the vehicle suffer continuous impact from front and rear vehicles, detecting passenger cabin state parameters, and determining structure safety; performing side column collision test, making the vehicle collide with a rigid cylinder at a preset speed and angle, monitoring key area state parameters, and determining vehicle safety; performing roof pressure test, applying a load on the roof, measuring deformation and head force, and determining the structure safety of the driver's cabin; and based on the comprehensive evaluation results of the four tests, dividing into four grades of excellent, good, qualified and unqualified. The application realizes the collaborative verification of vehicle structure safety and battery system electrical safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile testing, in particular to a new energy vehicle extreme condition collision safety test method. BACKGROUND

[0002] With the rapid popularization of new energy vehicles, consumers' attention to their safety performance is increasing. Traditional collision test standards mainly target regular conditions, while in actual road traffic accidents, vehicles may face more complex extreme conditions, such as bottom scraping collision, multi-vehicle chain collision, column collision, and roof pressing, etc. At present, the collision safety test methods for these extreme conditions at home and abroad are not perfect, there is a lack of unified evaluation standard, and it is difficult to effectively evaluate the safety performance of new energy vehicles in extreme conditions.

[0003] IIHS, Euro NCAP and other international institutions have carried out a lot of research in the field of vehicle safety testing, and have developed some related test procedures, such as small overlap collision, side column collision, roof strength test, etc. These tests have played a positive role in improving vehicle safety performance, but also have some limitations. For example, the test conditions are not specifically designed for new energy vehicles, and the special safety risks of new energy vehicles are not considered; the test scene is relatively single and cannot fully cover the extreme conditions.

[0004] The 2024 version of C-NCAP has included some electric safety related test items in the electric vehicle safety evaluation procedure, such as bottom scraping test. In addition, some universities and research institutions have also carried out related research. However, overall, the research on the collision safety test method of new energy vehicles under extreme conditions in China is not systematic and in-depth, and there is a lack of unified test standard and evaluation system. Internationally, there is no test standard specifically for the collision safety of new energy vehicles under extreme conditions.

[0005] Therefore, the present application proposes to develop and implement a scientific, comprehensive and highly operable new energy vehicle extreme condition collision safety test method, to provide technical support for evaluating and improving the safety performance of new energy vehicles under extreme conditions. SUMMARY

[0006] In view of this, the present application proposes a new energy vehicle extreme condition collision safety test method, aiming to solve the problem of being unable to specifically test the collision safety of new energy vehicles under extreme conditions.

[0007] The present application proposes a new energy vehicle extreme condition collision safety test method, comprising:

[0008] The bottom scraping test is performed by controlling the new energy vehicle to pass through a preset depth of the water area at a preset speed, and the chassis collides with the obstacle of a preset size at a preset overlap rate, the battery state parameters of the battery system are monitored in real time, and the battery safety performance is determined according to the preset battery standard parameters;

[0009] The front and rear pinch collision test is performed by making the new energy vehicle simultaneously suffer from the continuous collision impact of the front and rear trolleys, detecting the passenger compartment state parameters, and determining the vehicle structure safety according to the preset passenger compartment standard parameters;

[0010] The side column collision test is performed by making the new energy vehicle collide with a rigid cylinder of a preset size at a preset speed and a preset angle, the impact position is located in the key area of the passenger compartment, the key area state parameters are monitored, and the vehicle structure safety is determined according to the key area standard parameters;

[0011] The top pressure test is performed by applying a static load based on the proportion of the curb weight at a preset position of the new energy vehicle, measuring the roof deformation and the force value of the passenger head model, and determining the driver cabin structure safety according to the preset roof deformation threshold and head pressure threshold;

[0012] Based on the comprehensive evaluation results of the four tests, a multi-dimensional weighted scoring system is used to calculate the safety performance score, the multi-dimensional weighted scoring system converts each test index into a standardized score, allocates weight coefficients according to the importance of each index, and obtains the total safety performance score by weighted summation; The safety performance score is divided into excellent, good, qualified and unqualified four levels according to the preset interval threshold.

[0013] Further, when the new energy vehicle passes through the preset depth of the water area at a preset speed, it includes:

[0014] The preset depth of the water area realizes multi-depth gradient through an adjustable water level control system, the adjustable water level control system includes a liquid level sensor and an electric regulating valve group, the liquid level sensor monitors the water level in real time and transmits the signal to the central controller, the central controller adjusts the opening of the electric regulating valve group according to the preset test scheme, and realizes the accurate control of the depth of the water area; The multi-depth gradient is dynamically generated according to the ground clearance parameters of the target test vehicle to simulate the chassis scraping scene when the vehicle continuously drives on different water depth road sections.

[0015] Further, when the chassis collides with the obstacle of a preset size at a preset overlap rate, it includes:

[0016] The preset size of the obstacle includes replaceable spherical obstacle modules and trapezoidal obstacle modules, and the obstacle is fixed to the bottom of the wading pool through a precise positioning platform, the precise positioning platform includes a three-axis displacement mechanism, the relative position of the obstacle and the test vehicle chassis is calibrated through a laser range finder, and it is ensured that the collision overlap rate is controlled within a preset range; the hardness of the obstacle is measured by a Shore hardness tester and controlled within a preset range to match the characteristics of the obstacle under different road scenes.

[0017] Further, when the new energy vehicle is subjected to continuous collision impact of the front dolly and the rear dolly at the same time, it includes:

[0018] The collision speed of the front dolly and the rear dolly is dynamically adjusted through an independent speed control system, the speed control system includes an encoder and a variable frequency drive motor, the encoder monitors the dolly speed in real time and feeds back the signal to the motion controller, and the motion controller adjusts the output power of the variable frequency drive motor through the PID algorithm;

[0019] The collision timing of the two dollies is managed through a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within a preset range.

[0020] Further, when the collision timing of the two dollies is managed through a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within a preset range, it includes:

[0021] The high-precision time synchronization system includes a GPS time module installed on each dolly, a central timing controller, and a wireless communication unit; the central timing controller generates a collision timing sequence conforming to the statistical law based on the time interval distribution characteristics of the continuous collision in the actual road traffic accident database, and sends accurate start instructions to each dolly through the wireless communication unit, so that the time interval of the front and rear collisions is controlled within a preset range.

[0022] Further, when the new energy vehicle collides with a preset size of a rigid cylinder at a preset speed and a preset included angle, and the impact position is located in the key area of the passenger compartment, it includes:

[0023] The range of the preset included angle is achieved through a rotary vehicle positioning platform, the rotary vehicle positioning platform includes a rotatable circular turntable and an angle feedback system; the angle feedback system is composed of a high-precision encoder, which monitors the included angle between the test vehicle and the rigid cylinder in real time; the determination of the key area of the passenger compartment is achieved through three-dimensional human body model positioning technology, and the central control system automatically adjusts the horizontal position and height of the rigid cylinder according to the calculation result of the high-risk area, so that the impact point accurately corresponds to the projection position of the driver's key body part in the vehicle coordinate system.

[0024] Further, the determination of the critical area of the passenger cabin is achieved by a three-dimensional human body model positioning technology, comprising:

[0025] The three-dimensional human body model positioning technology comprises a virtual cabin model constructed based on the internal space data of the test vehicle model, a multi-body dynamics human body model matched with the virtual cabin model, and the high-risk area determined by finite element analysis.

[0026] Further, when a static load based on the proportion of the total mass is applied to the predetermined position of the new energy vehicle, it comprises:

[0027] The uniform loading of the static load is achieved by an electro-hydraulic servo loading system, which comprises a hydraulic cylinder, a servo valve group and a pressure sensor; the pressure sensor monitors the loading force in real time and feeds back the signal to the closed-loop control system, which adjusts the opening of the servo valve group through the PID algorithm; the deformation rate of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, and when the deformation rate exceeds the predetermined safety threshold, the closed-loop control system immediately terminates the loading process.

[0028] Further, the rate of roof deformation is monitored in real time by a non-contact three-dimensional optical measurement system, comprising:

[0029] The non-contact three-dimensional optical measurement system comprises a multi-angle arrangement of high-speed cameras, a digital image correlation processing unit and a real-time deformation calculation module; the real-time deformation calculation module performs feature point tracking and displacement field calculation on the image sequence captured by the high-speed camera to obtain three-dimensional deformation data of the roof surface, and calculates the deformation rate by numerical differentiation method.

[0030] Compared with the prior art, the beneficial effects of the present application are that through the multi-dimensional scene simulation of the bottom scraping water test, the front and rear pinch collision test, the side column collision test and the roof pressing test, a variety of extreme risk environments that the new energy vehicle may encounter in real road use are comprehensively covered, and the collaborative verification of the vehicle structure safety and the battery system electrical safety is realized. In the bottom scraping water test, through the adjustable water level control system, the dynamic adjustment of multiple depth gradients is realized, and combined with the modular design of the obstacle and the three-axis precise positioning platform, the repeatability of the chassis scraping working condition and the controllability of the collision overlap rate are ensured; in the front and rear pinch collision test, through the independent speed control system and the high-precision time synchronization system, the speed adjustment and time sequence management of the front and rear vehicles are realized, which can truly reproduce the time interval distribution characteristics of the road continuous collision, and ensure the high consistency of the test and the actual accident environment; in the side column collision test, through the rotating vehicle positioning platform and the three-dimensional human body model positioning technology, the key areas of the passenger compartment can be accurately locked, which ensures that the impact point of the rigid column corresponds to the high-risk body parts of the driver and passengers, and improves the pertinence and scientificity of the test; in the roof pressing test, the electro-hydraulic servo loading system and the non-contact three-dimensional optical measurement system are used to realize the uniform loading of the static load and the real-time monitoring of the roof deformation rate, and when the deformation rate exceeds the preset threshold, the loading can be terminated immediately, which not only ensures the test safety, but also improves the monitoring accuracy and data reliability. During the test process, the passenger compartment intrusion amount, the door opening performance, the battery system insulation resistance state, the electrolyte leakage condition, the thermal runaway risk and the head force and other key indicators are monitored, realizing the all-round coverage of the vehicle structure safety, electrical safety and passenger protection performance. Through the multi-dimensional weighted scoring system, the four types of test results are standardized and weighted, which can objectively generate a unified safety performance comprehensive score, and according to which four levels of excellent, good, qualified and unqualified are divided, which not only enhances the comparability and universality of the results, but also provides a unified basis for the safety performance evaluation of different vehicle models. BRIEF DESCRIPTION OF DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustration only and are not intended to limit the application thereto. Moreover, in the drawings, like reference numerals designate like parts throughout the several views. In the drawings:

[0032] Figure 1 The flowchart of the new energy vehicle extreme working condition collision safety test method provided by the embodiments of the present application. DETAILED DESCRIPTION

[0033] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] While existing safety testing systems for new energy vehicles draw upon traditional crash test standards for gasoline-powered vehicles to some extent, they still have significant shortcomings under extreme conditions. On one hand, current standards primarily focus on conventional scenarios such as frontal collisions, side collisions, rear-end collisions, and roof crush tests, failing to comprehensively simulate the complex and extreme conditions new energy vehicles may face on real roads. These include battery pack damage caused by water damage, high-voltage system power failure due to chain collisions, electrolyte leakage risks under side cylindrical impacts, and secondary injuries to occupants caused by roof crushing. On the other hand, while international organizations such as IIHS and Euro NCAP have established relatively mature procedures for small overlap crashes, side pole impacts, and roof strength tests, these tests do not fully consider the unique safety hazards of new energy vehicle battery systems, such as insulation resistance degradation, thermal runaway propagation, and electrolyte leakage. Furthermore, current testing methods are mostly single-condition verifications, lacking a comprehensive evaluation system with multi-dimensional indicators. This results in test results that cannot fully reflect the true safety performance of new energy vehicles under extreme conditions, making it difficult to provide systematic references for product design optimization and policy and regulatory formulation.

[0035] For example, in 2023, a certain brand of new energy vehicle encountered a flooded section of road while driving at high speed. The battery pack at the bottom of the vehicle suffered structural damage due to water damage, resulting in a sudden drop in insulation resistance and a partial short circuit. Following the accident, the vehicle experienced thermal runaway and caught fire within a short period, causing severe damage. This case demonstrates that existing testing methods fail to adequately cover extreme usage scenarios such as water damage and lack specialized verification methods for the insulation performance and thermal runaway risks of battery systems. This reflects a significant deficiency in the traditional testing system's ability to address the unique safety risks of new energy vehicles. This further highlights the necessity and urgency of establishing scientific and systematic collision safety testing methods for new energy vehicles under extreme operating conditions.

[0036] For this, please refer to Figure 1 As shown, a crash safety test method for new energy vehicles under extreme operating conditions is proposed, including:

[0037] S100: Perform the bottom scraping test by controlling the new energy vehicle to pass through the preset depth of the water area at a preset speed, and make the chassis collide with the obstacle of a preset size at a preset overlap rate, monitor the battery state parameters of the battery system in real time, and determine the battery safety performance according to the preset battery standard parameters;

[0038] S200: Perform the front and rear pinch collision test by making the new energy vehicle suffer continuous collision impact from the front and rear trolleys at the same time, detect the passenger compartment state parameters, and determine the vehicle structure safety according to the preset passenger compartment standard parameters;

[0039] S300: Perform the side column collision test by making the new energy vehicle collide with a rigid cylinder of a preset size at a preset angle at a preset speed, the impact position being located in the key area of the passenger compartment, monitoring the key area state parameters, and determining the vehicle structure safety according to the key area standard parameters;

[0040] S400: Perform the roof pressing test by applying a static load based on the proportion of the curb weight at a preset position of the new energy vehicle, measuring the roof deformation and the force value of the passenger head model, and determining the driver cabin structure safety according to the preset roof deformation threshold and head pressure threshold;

[0041] S500: Based on the comprehensive evaluation results of the four tests, the safety performance score is calculated by using a multi-dimensional weighted scoring system, the multi-dimensional weighted scoring system converts each test index into a standardized score, the weight coefficients are allocated according to the importance of each index, and the total safety performance score is obtained by weighted summation; the safety performance score is divided into four levels of excellent, good, qualified and unqualified according to the preset interval threshold.

[0042] Among them, the battery state parameters include insulation resistance state, electrolyte leakage and thermal runaway risk; the battery standard parameters include insulation resistance threshold, no electrolyte leakage and no thermal runaway phenomenon; the passenger compartment state parameters include structure intrusion amount, door opening performance, high voltage system power-off signal and battery system safety state; the passenger compartment standard parameters include structure intrusion amount threshold, door can be normally opened, insulation resistance state; the key area state parameters include door opening performance, battery system safety state and passenger compartment intrusion amount; the key area standard parameters include door can be normally opened, insulation resistance state meets the standard, no electrolyte leakage and no thermal runaway phenomenon.

[0043] The new energy vehicle limit condition crash safety test method constructs a complete limit condition safety evaluation system through systematic implementation of four core tests, including bottom scraping test, front and rear impact test, side column impact test and top pressure test. In the implementation process of the bottom scraping test, a water area with multiple depth gradients is constructed. The water area is accurately controlled through an adjustable water level control system, which includes a liquid level sensor and an electric regulating valve group. The liquid level sensor monitors the water level in real time and transmits the signal to the central controller. The central controller adjusts the opening of the electric regulating valve group according to the preset test scheme to accurately control the depth of the water area. The multiple depth gradients are dynamically generated according to the ground clearance parameters of the target test vehicle to simulate the chassis scraping scene when the vehicle continuously drives on road sections with different water depths. The specific water depth is set to 300mm to meet the requirements of the C-NCAP management rules (2024 edition) Appendix N electric vehicle bottom scraping test procedure. At the same time, the obstacle with a preset size is designed in a modular way, including replaceable spherical obstacle modules and trapezoidal obstacle modules. The diameter of the spherical obstacle module is 150mm. The obstacle is fixed on the bottom of the water pool through a precision positioning platform. The precision positioning platform includes a three-axis displacement mechanism. The relative position of the obstacle and the test vehicle chassis is calibrated through a laser range finder to ensure that the overlap rate is controlled within the preset range. The specific overlap rate is 30mm+0~4mm between the top of the bottom scraping tool and the lowest position of the battery pack under the condition of the vehicle's kerb mass, to accurately simulate the actual collision situation. The hardness of the obstacle is measured by a Shore hardness tester and controlled within the preset interval to match the obstacle characteristics in different scenarios such as urban road speed reduction zone, rural road stone and highway shoulder. During the test, the vehicle is immersed in water with a specified depth and kept soaking for 1 hour to simulate real-world conditions. Then the vehicle is pushed towards the obstacle at a preset speed of 30km / h. During the entire impact process, the insulation resistance state of the battery system, the electrolyte leakage situation and the thermal runaway risk are monitored in real time through a distributed sensing network, which includes a temperature sensor array installed at key positions of the battery pack, a data acquisition interface connected to the battery management system (BMS) and a safety evaluation server. The temperature sensor array covers the bottom, middle and surrounding areas of the battery pack with a sampling frequency not less than 100Hz. The data acquisition interface obtains voltage, current and insulation resistance data in the BMS in real time through CAN bus with a transmission delay controlled within 10ms. The safety evaluation server runs a safety state evaluation algorithm. First, the collected temperature data is processed by spatial interpolation to construct a three-dimensional temperature field model of the battery pack. Then the temperature gradient change rate and the maximum temperature rise rate are calculated. When the temperature gradient change rate exceeds the preset threshold or the maximum temperature rise rate is greater than 5℃ / s, it is determined as a potential thermal runaway risk and a graded early warning mechanism is triggered. Finally, the electrical safety performance is determined according to the insulation resistance value not less than 500Ω / V, no electrolyte leakage, no smoking, no fire or explosion phenomenon.In the implementation process of the front and rear pinch collision test, the test vehicle is subjected to continuous collision impact from the front sled and the rear sled, both of which are 1.7T (S-CMDB) cars, and the collision speed is 50 km / h, which is obviously higher than the standard of 1.1T and 50 km / h specified in the national standard, so as to more strictly simulate the actual collision scene; the collision speed of the front sled and the rear sled is dynamically adjusted through an independent speed control system, including an encoder and a variable frequency drive motor, the encoder monitors the speed of the sled in real time and feeds back the signal to the motion controller, the motion controller adjusts the output power of the variable frequency drive motor through the PID algorithm, so as to realize the accurate control of the speed of the sled; the collision time sequence of the two sleds is managed through a high-precision time synchronization system, including a GPS time module installed on each sled, a central time sequence controller and a wireless communication unit, the central time sequence controller generates a collision time sequence conforming to the statistical law based on the time interval distribution characteristics of the continuous collision in the actual road traffic accident database, and sends accurate start instructions to each sled through the wireless communication unit, so that the time interval of the front and rear collision is controlled within the preset range; during the test, necessary data acquisition equipment is installed on the target vehicle and dummies are placed according to the regulations, including a front row driver Hybrid III 50th male dummy, a front row co-driver Hybrid III 50th male dummy, a rear row driver side Hybrid III 5th female dummy and a rear row co-driver side Q3 child dummy; the front and rear collisions are carried out in the selected order, and various data are recorded during the entire impact process; after the impact, the passenger compartment structure intrusion amount, the door opening performance, the high voltage system power-off signal and the battery system safety state are detected, and the vehicle structure safety is judged according to the following conditions: the A-pillar rear displacement is not more than 200mm, the steering column displacement (i.e. steering wheel) center position upward displacement is between 72mm-88mm, the steering column rear displacement is between 90mm-110mm, the rear intrusion amount meets the requirement that the rear compartment interior part cannot contact the last row seat, the door can be normally opened, the insulation resistance value is not less than 500Ω / V and there is no thermal runaway phenomenon; in the implementation process of the side column collision test, the preset angle range is realized through a rotary vehicle positioning platform, which includes a rotatable circular turntable and an angle feedback system composed of a high-precision encoder, which monitors the angle between the test vehicle and the rigid cylinder in real time, to ensure that the vehicle angle is accurately controlled at 75°; the determination of the key area of the passenger compartment is realized through three-dimensional human body model positioning technology, which includes a virtual cockpit model constructed based on the internal space data of the test vehicle, a multi-body dynamics human body model matched with the virtual cockpit model and a high-risk area determined through finite element analysis, and the central control system automatically adjusts the horizontal position and height of the rigid cylinder according to the calculation results of the high-risk area, so that the impact point accurately corresponds to the centroid position of the co-driver's head.The vehicle or movable platform is pushed at a preset speed of 32 km / h to collide with a static rigid cylinder, and various data are recorded during the entire collision process; after the collision, the intrusion amount of the passenger compartment structure is detected by a high-precision three-dimensional deformation measurement system, including a plurality of marker points installed inside the passenger compartment, a high-speed stereo camera arranged around the test area, and an image processing workstation; the high-speed stereo camera synchronously captures the motion trajectory of the marker points at a rate of 1000 frames per second, with a spatial resolution of 0.1 mm; the image processing workstation runs a three-dimensional reconstruction algorithm to calculate the deformation amount of the key structural parts; finally, the vehicle structure safety is determined according to the normal opening of the door, the insulation resistance value not less than 500Ω / V, no electrolyte leakage and no thermal runaway phenomenon; during the implementation of the roof crush test, the uniform loading of the static load is realized by an electro-hydraulic servo loading system, including a hydraulic cylinder, a servo valve group and a pressure sensor; the pressure sensor monitors the loading force in real time and feeds back the signal to the closed-loop control system; the closed-loop control system adjusts the opening of the servo valve group through the PID algorithm, so that the loading force increases linearly at a preset rate; the roof crush position is set on the B-pillar on the left side of the main driver of the vehicle, and the external force applied is 4 times the vehicle unladen mass, specifically 73.71 kN, which is significantly higher than the 3 times force (maximum 45 kN) specified in the national standard, and is 1.6 times the national standard; the deformation rate of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, including a high-speed camera arranged at multiple angles, a digital image correlation processing unit and a real-time deformation calculation module; the real-time deformation calculation module performs feature point tracking and displacement field calculation on the image sequence captured by the high-speed camera to obtain three-dimensional deformation data of the roof surface, and calculates the deformation rate by numerical differentiation method; when the deformation rate exceeds the preset safety threshold, the closed-loop control system immediately terminates the loading process; the quasi-static load is applied to the roof at a specified rate at a specified position, and various data are recorded during the entire test process; the final roof deformation and the stress value of the passenger head model are measured, and the driver cabin structure safety is determined according to the roof deformation less than 127 mm and the driver head pressure less than 222 N; the entire test process is carried out under specified environmental conditions, including environmental temperature 5-35℃, relative humidity 45-75% and air pressure 86-106 kPa; high-precision sensors are used to collect vehicle acceleration, structural deformation and battery state parameters, and the data are analyzed and processed by signal filtering, damage standard calculation and multi-source data fusion, to ensure the accuracy and reliability of the test results.

[0044] The four test results are comprehensively evaluated by a multi-dimensional weighted scoring system, each test index is converted into a standardized score, a weight coefficient is assigned according to the importance of the index, and after weighted summation, the safety performance is divided into four levels of excellent, good, qualified and unqualified according to the preset interval threshold. In the index normalization unit, the range standardization method is used to convert each test index into a dimensionless score of 0-100 points. In the weight distribution unit, the weight coefficients of each test index are determined based on the analytic hierarchy process. In the comprehensive scoring unit, the normalized index score and the corresponding weight coefficient are weighted and summed. In the grade determination unit, the threshold interval of each grade is dynamically determined according to the distribution characteristics of the historical test data, so as to realize comprehensive and scientific evaluation of the safety performance of new energy vehicles under extreme working conditions.

[0045] Specifically, the safety judgment of each test follows strict and specific threshold rules: in the bottom scraping test, the insulation resistance threshold is set to be no less than 500Ω / V (measured by the ammeter method), the electrolyte leakage judgment uses a high-sensitivity chemical sensor for monitoring, and once electrolyte leakage is detected, it is judged as unqualified, the thermal runaway risk judgment is based on temperature monitoring data, when the temperature gradient change rate exceeds the preset threshold or the maximum temperature rise rate is greater than 5℃ / s, the third level early warning mechanism is triggered, and if smoke, fire or explosion occurs, it is directly judged as unqualified for electrical safety performance; in the front and rear pinch impact test, the structure intrusion amount threshold is set to be no more than 200mm for the rear displacement of the A-pillar, the steering column displacement (steering wheel) center position is strictly controlled between 72mm-88mm upward displacement and 90mm-110mm rearward displacement, the rear intrusion amount judgment standard is that the interior trim in the tail compartment cannot contact the last row of seats, the door opening performance judgment requires all doors to be normally opened by the occupant within 5 seconds after the collision, the insulation resistance state judgment is the same as the bottom scraping test, and at the same time, the high-voltage system is required to complete power-off within 120ms and no thermal runaway phenomenon; in the side column impact test, the door opening performance judgment standard is consistent with the front and rear pinch test, the insulation resistance threshold is also no less than 500Ω / V, the electrolyte leakage judgment uses the same high-sensitivity monitoring method as the bottom scraping test, and the thermal runaway risk judgment is based on the distributed temperature monitoring network, when the temperature abnormal rise rate exceeds 3℃ / s or voltage drop is detected, it is judged as potential risk; in the roof pressure test, the roof deformation threshold is set to be less than 127mm (accurately measured by a non-contact three-dimensional optical measurement system), and the driver head model pressure threshold is set to be less than 222N (measured using a US standard test model), when the deformation rate exceeds the safety threshold, the loading is automatically terminated to protect the test equipment; all tests are carried out under the conditions of environmental temperature 5-35℃, relative humidity 45-75%, and air pressure 86-106kPa, the data acquisition system records key parameters at a frequency of not less than 100Hz, and finally the multi-dimensional weighted scoring system is used to convert each index into a standardized score of 0-100 points, when all single tests meet the safety threshold and the comprehensive score is not less than 60 points, it is judged as qualified, the comprehensive score of 60-79 points is qualified, 80-89 points is good, and 90 points and above is excellent, and any key test item that does not meet the standard is directly judged as unqualified, ensuring comprehensive and accurate evaluation of the safety performance of new energy vehicles under extreme working conditions.

[0046] As a preferred embodiment, the scheme of the application is implemented as follows: a certain brand of pure electric SUV (model EV-7, curb weight 2457 kg, equipped with 85 kWh ternary lithium battery) is subjected to extreme condition crash safety test under the conditions of ambient temperature of 5-35℃ and relative humidity of 45-75%. First, the test team constructs a wading pool with a length of 10 m, a width of 4 m and a depth of 0.5 m, accurately sets the wading depth to 300 mm through an adjustable water level control system, selects a spherical obstacle module with a diameter of 150 mm made of high-hardness alloy steel and coated with a polyurethane elastic layer on the surface, ensures that the overlap rate between the obstacle and the lowest point of the battery pack is 32 mm (meeting the requirement of 30 mm+0-4 mm) through a precise positioning platform and a laser range finder, and pushes the vehicle to collide with the obstacle at a speed of 30 km / h after soaking in water for 1 hour. The distributed sensor network monitors the temperature at 15 key positions of the battery pack at a frequency of 100 Hz throughout the process, and the CAN bus acquires BMS data in real time. The results show that the insulation resistance value is 586 Ω / V (higher than the threshold value of 500 Ω / V), there is no electrolyte leakage, and the maximum temperature rise rate of 3.8℃ / s does not trigger a thermal runaway warning. Then, the front and rear impact test is carried out. Two 1.7T (S-CMDB) cars collide with the test vehicle from the front and rear at a speed of 50 km / h. A high-precision time synchronization system accurately controls the collision timing. The test vehicle is placed according to the regulations with a Hybrid III 50th male dummy (front main and co-driver), a Hybrid III 5th female dummy (rear driver side) and a Q3 child dummy (rear co-driver side). The results show that the A-pillar displacement is 187 mm, the steering column displacement is 82 mm upward and 102 mm backward, all within the safe range, all doors can be normally opened, the insulation resistance value is 568 Ω / V, and there is no thermal runaway phenomenon. Then, the side column impact test is carried out. The 75° collision angle is accurately set through a rotating vehicle positioning platform, and the vehicle collides with a rigid cylinder with a diameter of 254 mm at a speed of 32 km / h. The impact point accurately corresponds to the head mass center position of the co-pilot driver. A high-precision three-dimensional deformation measurement system records the deformation data at a rate of 1000 frames per second. The results show that the door can be normally opened, the insulation resistance value is 542 Ω / V, there is no electrolyte leakage and thermal runaway phenomenon. Finally, the roof pressure test is carried out. A 73.71kN (4 times of the curb mass) static load, the electro-hydraulic servo loading system accurately controls the loading rate through the PID algorithm, the non-contact three-dimensional optical measurement system monitors the deformation in real time, and the loading is stopped when the roof deformation reaches 118mm, the driver's head model pressure is 205N, and all meet the safety requirements; based on the four test results, the multi-dimensional weighted scoring system converts each index into a standardized score, and after weight distribution and weighted calculation, the safety performance score of the vehicle is 87 points, which is divided into the "good" level according to the preset interval threshold, indicating that the new energy vehicle has good safety performance under extreme conditions, which can effectively protect the safety of passengers and ensure the stability of the battery system.

[0047] Through the above scheme, the applicant can simulate the extreme condition of the chassis contacting the obstacle under the conditions of wading and complex road conditions through the bottom scraping test, monitor the insulation resistance state, electrolyte leakage and thermal runaway risk of the battery system in real time, and comprehensively evaluate the electrical safety performance; through the front and rear pinch collision test, it can truly reproduce the high-risk accident scene of road chain rear-end collision, verify the passenger compartment intrusion amount, door openability and power-off protection effect of the high-voltage electrical system, and ensure the vehicle structure and passenger safety; through the side column impact test, the anti-intrusion capability and battery safety state of the vehicle under the impact of a narrow force surface can be accurately investigated, and the protection level of the key parts of the passengers is highlighted; through the roof pressure test, the deformation amount of the vehicle roof under static crushing and the protection capability of the driver's head can be quantitatively evaluated, so as to determine the safety of the driver's cabin structure.

[0048] The application further proposes that when the new energy vehicle passes through a preset depth of the wading area at a preset speed, it comprises:

[0049] The preset depth of the wading area realizes multi-level depth gradient through an adjustable water level control system, the adjustable water level control system comprises a liquid level sensor and an electric regulating valve group, the liquid level sensor monitors the water level in real time and transmits the signal to the central controller, the central controller adjusts the opening of the electric regulating valve group according to the preset test scheme, and realizes the accurate control of the depth of the wading area; the multi-level depth gradient is dynamically generated according to the ground clearance parameters of the target test vehicle, so as to simulate the chassis scraping scene of the vehicle when continuously driving on road sections with different water depths.

[0050] In the new energy vehicle bottom scraping test, the depth control of the water area is realized by the adjustable water level control system to ensure that the test can accurately simulate the effect of the water accumulation environment on the vehicle chassis in the actual road. Including liquid level sensor, electric regulating valve group and central controller, the liquid level sensor is distributed in the key position of the water area, which can collect the water level height in real time and transmit the data to the central controller. According to the preset test scheme and the ground clearance parameters of the target vehicle, the central controller dynamically calculates and generates multi-stage depth gradient scheme, controls the electric regulating valve group to adjust the water flow, and realizes the accurate control of each water level. When the vehicle enters the water area at a preset speed, the chassis will experience multi-stage scraping conditions from shallow water to deep water, and the contact position and overlap rate of the chassis and the obstacle can be controlled through the modular design and precise positioning platform of the obstacle, which can realize high consistency with the actual road conditions. During the whole process, the test system can adjust the water level gradient repeatedly to adapt to the difference of chassis height of different vehicles, and can record the chassis contact condition and battery system stress state under each depth water level, providing comprehensive data support for electrical safety and structural safety. This method allows real-time monitoring and analysis by combining temperature sensors, battery management system data interface and safety evaluation server, to evaluate the impact of chassis scraping on battery pack insulation performance, electrolyte leakage risk and potential risks of thermal runaway, and realize the overall safety performance verification of new energy vehicles in complex water scenarios.

[0051] As a preferred embodiment, the scheme of the application is implemented as follows: In actual testing, for an electric SUV with a ground clearance of 180mm, the water area is realized by a three-stage depth gradient through an adjustable water level control system, which is set to 150mm, 200mm and 250mm respectively to simulate the continuous driving scenario of urban water accumulation and light water area. The liquid level sensor collects water level data in real time and transmits it to the central controller, which automatically adjusts the opening of the electric regulating valve group according to the preset test scheme to realize accurate control of water depth. When the vehicle passes through the water area at a speed of 30km / h, the chassis collides with the obstacle with a preset overlap, while monitoring the battery pack bottom insulation resistance, electrolyte leakage and temperature change, to ensure comprehensive evaluation of the safety impact of chassis scraping on the battery system under different water depth gradients, effectively simulating the chassis collision risk under various water depth conditions in the actual road.

[0052] Through the above technical scheme, the application realizes accurate simulation and evaluation of the chassis scraping condition of new energy vehicles under various water depths, ensures that the actual stress and temperature change of the chassis, battery system and key structural parts during the test process are fully monitored and recorded, thereby identifying potential electrical safety and structural risks in advance. At the same time, the dynamic setting of multi-stage depth gradient can cover the ground clearance difference of different vehicles, improving the applicability and scientificity of the test.

[0053] The application further proposes that when the chassis collides with the preset size obstacle at a preset overlap rate, the application includes:

[0054] The preset size obstacle includes replaceable spherical obstacle modules and trapezoidal obstacle modules, and the obstacle is fixed to the bottom of the wading pool through a precise positioning platform. The precise positioning platform includes a three-axis displacement mechanism, and the relative position of the obstacle and the test vehicle chassis is calibrated through a laser range finder to ensure that the collision overlap rate is controlled within a preset range. The hardness of the obstacle material is measured by a Shore hardness tester and controlled within a preset interval to match the obstacle characteristics under different road conditions.

[0055] In the process of implementing the chassis collision test with the preset size obstacle, the obstacle adopts a modular design, including replaceable spherical obstacle modules and trapezoidal obstacle modules to adapt to different road working condition simulation requirements. Each obstacle module is fixed to the bottom of the wading pool through a precise positioning platform, and the precise positioning platform is equipped with a three-axis displacement mechanism that can accurately adjust the position and height of the obstacle in X, Y, and Z directions, thereby achieving high-precision alignment with the test vehicle chassis. To ensure accurate control of the collision overlap rate, the entire positioning process relies on a laser range finder to measure the distance between the obstacle and the vehicle chassis key points in real time. The measurement data is fed back to the central controller in real time, and the central controller automatically adjusts the three-axis displacement mechanism according to the preset overlap rate requirements to ensure that the contact position and overlap amount of the chassis and the obstacle during the collision meet the test standards. At the same time, the hardness of the obstacle material is strictly measured by a Shore hardness tester and controlled within a preset interval to simulate the obstacle characteristics of urban road speed bumps, rural road stones, and highway shoulders in different actual scenarios, thereby reflecting the chassis stress, structural deformation, and possible impact on the battery system during the collision.

[0056] As a preferred embodiment, the scheme of the application is implemented as follows: In a one-time underbody collision test of a certain type of pure electric SUV, the test team sets the diameter of the spherical obstacle module to 150mm and accurately fixes it at the specified position on the bottom of the wading pool through the three-axis displacement mechanism. The relative position between the obstacle and the vehicle chassis is calibrated in real time using a laser range finder to ensure that the lowest point of the battery pack and the top of the obstacle achieve a preset overlap rate of 30mm±2mm when the vehicle passes at a speed of 30km / h. To simulate real road conditions, the hardness of the obstacle material is measured and controlled by a Shore hardness tester to be 55±5H, similar to the hardness level of urban road speed bumps. During the test, the vehicle continuously immerses in the wading area and collides with the obstacle, and the distributed sensing network collects chassis stress, battery pack insulation resistance, and temperature change data in real time, successfully verifying the safety performance of the battery pack and chassis under actual collision in the waterlogged section.

[0057] By the technical scheme, the replaceable spherical and trapezoidal obstacle modules are adopted, and precise three-axis displacement platforms and laser range finders are used for accurate positioning, so that the collision overlap rate of the chassis and the obstacles can be strictly controlled, and the simulation result is ensured to be highly close to the real road working condition. The hardness of the obstacle material is strictly measured and controlled, various road scenes such as urban speed reduction zone, rural stone and highway shoulder can be simulated, the stress and crashworthiness of the chassis structure, battery pack and key safety components are comprehensively evaluated, and the structural safety and battery system protection performance of the new energy vehicle under the extreme scraping bottom working condition are verified.

[0058] The application further proposes that when the new energy vehicle is simultaneously subjected to the continuous collision impact of the front trolley and the rear trolley, it comprises:

[0059] The collision speed of the front trolley and the rear trolley is dynamically adjusted by an independent speed control system, the speed control system comprises an encoder and a variable frequency drive motor, the encoder monitors the trolley speed in real time and feeds back the signal to the motion controller, and the motion controller adjusts the output power of the variable frequency drive motor through the PID algorithm;

[0060] The collision time sequence of the two trolleys is managed by a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within a preset range.

[0061] In the process of implementing the front and rear impact test, the new energy vehicle is simultaneously subjected to the continuous impact of the front trolley and the rear trolley to comprehensively simulate the real road multi-vehicle continuous collision scene. The collision speed of the front trolley and the rear trolley is accurately adjusted by an independent speed control system, which is composed of a high-resolution encoder and a variable frequency drive motor. The encoder collects trolley speed data in real time and feeds back to the motion controller. The motion controller continuously adjusts the output power of the variable frequency drive motor through the PID closed-loop control algorithm to realize dynamic and accurate control of the trolley speed, so that the collision speed reaches the preset standard, and at the same time ensures that the vehicle is uniformly stressed during the collision and meets the actual working condition requirements. The collision time sequence of the two trolleys is coordinated by a high-precision time synchronization system, including a GPS time module, a central time sequence controller and a wireless communication unit. The central time sequence controller generates a collision sequence based on the statistical characteristics of the continuous collision time interval in the real traffic accident database, and sends a start instruction through the wireless communication unit to strictly control the time interval of the front and rear collisions within a preset range, thereby accurately reproducing the continuous impact mode of the accident. During the entire test process, the acceleration, displacement and stress of the key structure of each trolley can be recorded in real time, and the safety state of the battery pack, electrical system and passenger compartment can be monitored in real time in combination with the multi-point sensor.

[0062] As a preferred embodiment, the scheme of the application is implemented as follows: in a front and rear pinch collision test, in order to evaluate the safety performance of new energy vehicles under the working condition of multiple vehicle continuous collision, the test team places the target vehicle on the collision road, the front and rear trolleys are both 1.7 tons of cars, and the collision speed is preset to 50 km / h. Each trolley is equipped with an independent speed control system, including a high-precision encoder and a variable frequency drive motor. The encoder collects the trolley speed in real time and feeds back the data to the motion controller. The controller continuously adjusts the motor output through the PID algorithm to ensure that the trolley reaches the accurate target speed before the collision. At the same time, through the central timing controller and the GPS synchronization module, the collision time interval of the front and rear trolleys is strictly controlled within 0.8 seconds ± 0.05 seconds, successfully reproducing the time sequence characteristics of vehicle continuous collision in actual traffic accidents. During the entire impact process, sensors record the passenger compartment intrusion, steering column displacement and battery system safety state of the target vehicle in real time.

[0063] Through the above technical scheme, the application can accurately control the trolley speed and collision time sequence through the front and rear pinch collision test method, ensuring that the continuous collision working condition is highly repeatable and controllable, reproducing the vehicle continuous force scenario in actual traffic accidents, thereby evaluating the passenger compartment structure safety, door opening performance and battery system safety state of new energy vehicles under extreme collision conditions. It can timely find potential structural weaknesses and electrical safety hazards.

[0064] The application further proposes that the collision time sequence of the two vehicles is managed by a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within the preset range, including:

[0065] The high-precision time synchronization system includes a GPS time module installed on each trolley, a central timing controller and a wireless communication unit. The central timing controller generates a collision time sequence that conforms to the statistical law based on the distribution characteristics of the continuous collision time interval in the actual road traffic accident database, and sends accurate start instructions to each trolley through the wireless communication unit, so that the time interval of the front and rear collisions is controlled within the preset range.

[0066] Wherein, in the implementation before and after the pinch collision test, the high-precision time synchronization system plays a key role in ensuring that the collision timing of the front and rear trolleys strictly meets the preset requirements. It is composed of GPS time modules installed on each trolley, a central timing controller, and a wireless communication unit. The GPS time module can provide a time signal with millisecond-level precision, ensuring a unified time reference for each trolley; the central timing controller generates a collision timing sequence that conforms to the actual traffic accident law based on the distribution characteristics of the time interval of successive collisions collected from the actual road traffic accident database, using statistical analysis and probability modeling methods, including the mean, standard deviation, and extreme value range of the collision interval; the wireless communication unit transmits the precise start command generated by the central timing controller to the execution unit of each trolley in real time, controls the start motor and brake system, and makes the trolley start within millisecond-level precision, ensuring that the time interval of the front and rear collisions is strictly controlled within the preset range.

[0067] As a preferred embodiment, the scheme of the present application is implemented as follows: in an actual new energy vehicle front and rear pinch collision test, the high-precision time synchronization system is used to accurately control the start timing of the front and rear trolleys. In the experiment, the front and rear trolleys are respectively equipped with GPS time modules to provide real-time unified time reference signals, and the central timing controller generates the start sequence of the front and rear trolleys according to the statistical characteristics of the time interval of successive collisions in the road traffic accident database, such as the start of the rear trolley within 500ms after the start of the front trolley to simulate a continuous rear-end accident. The wireless communication unit accurately transmits the start command to the control systems of the two trolleys, making the trolleys start and accelerate at the same time according to the set time interval, thereby ensuring that the time interval when the collision occurs strictly meets the preset parameters. During the entire process, the trolley speed, acceleration, and mechanical response at the moment of collision are recorded synchronously, providing real and reliable data support for evaluating the structural safety and occupant protection of vehicles under continuous collision conditions.

[0068] Through the above technical scheme, the present application uses the GPS time module to provide a unified time reference, the central timing controller generates a collision timing sequence that conforms to the statistical law according to the real road traffic accident database, and the precise start command is transmitted to each trolley through the wireless communication unit, achieving precise control of the time interval of the front and rear collisions, thereby realistically simulating the dynamic response process of the vehicle in a multi-vehicle rear-end or successive collision accident.

[0069] The present application further proposes that when a new energy vehicle collides with a rigid cylinder of a preset size at a preset speed and a preset angle, and the collision position is located in the key area of the passenger compartment, it includes:

[0070] The preset angle range is achieved by a rotating vehicle positioning platform, which comprises a rotatable circular turntable and an angle feedback system; the angle feedback system is composed of a high-precision encoder, which monitors the angle between the test vehicle and the rigid cylinder in real time; the determination of the key area of the passenger compartment is achieved by three-dimensional human body model positioning technology; the central control system automatically adjusts the horizontal position and height of the rigid cylinder according to the calculation results of the high-risk area, so that the impact point accurately corresponds to the projection position of the driver's key body parts in the vehicle coordinate system.

[0071] In the implementation of the side column impact test, the impact angle between the new energy vehicle and the rigid cylinder is accurately controlled by the rotating vehicle positioning platform to ensure that the collision conditions meet the preset test scheme. The rotating vehicle positioning platform comprises a rotatable circular turntable and a high-precision angle feedback system, and the angle feedback system is composed of a precision encoder, which can monitor the angle change of the test vehicle relative to the rigid cylinder in real time and transmit data to the central control system, realize dynamic adjustment and closed-loop control, and keep the vehicle in the preset angle range. The positioning of the key area of the passenger compartment is completed by relying on three-dimensional human body model positioning technology, which constructs a virtual cabin model based on the internal space data of the target vehicle and maps the multi-body dynamics human body model to the virtual cabin, and calculates the high-risk area of the occupant in the collision through finite element analysis. The central control system can automatically adjust the position of the rigid cylinder in the horizontal direction and the height direction according to the calculation results of the high-risk area, so that the impact point accurately corresponds to the projection position of the driver's or passenger's key body parts in the vehicle coordinate system, so as to ensure that the collision impact truly reproduces the force on the occupant. The acceleration, structural deformation and dummy force data of the vehicle can be continuously recorded during the test, providing high-precision and repeatable data support for subsequent safety evaluation, improving the scientificity and reliability of the collision test, and helping to optimize the design of vehicle side protection structure and passenger protection scheme.

[0072] As a preferred embodiment, the scheme of the application is implemented as follows: in a side column impact test for a medium-sized new energy vehicle, the test vehicle is driven to the rotating vehicle positioning platform at a speed of 50 km / h, and the impact angle between the test vehicle and the rigid cylinder is controlled to be 30°. The impact point is accurately positioned on the projection position of the driver's key body parts in the vehicle coordinate system, and the acceleration, structural deformation and dummy force data of the vehicle are continuously recorded during the test, providing high-precision and repeatable data support for subsequent safety evaluation, improving the scientificity and reliability of the collision test, and helping to optimize the design of vehicle side protection structure and passenger protection scheme. The preset speed of the vehicle is driven to the stationary rigid cylinder, the impact angle is accurately controlled at 75° by a rotating vehicle positioning platform, a high-precision encoder on the platform monitors the angle between the vehicle and the cylinder in real time, and data is transmitted to a central control system for dynamic adjustment. Before the test, a virtual cabin model is constructed by three-dimensional human body positioning technology, and a driver human body dynamics model is mapped into the cabin to identify high-risk areas such as the head, chest and hip of the co-driver. The central control system automatically adjusts the horizontal position and height of the rigid cylinder according to the calculation results of these high-risk areas, so that the impact point accurately corresponds to the projection of the center of mass of the co-driver's head, and the real passenger force simulation is realized. During the entire impact process, a high-speed camera, an acceleration sensor and a force sensor built-in dummy record the vehicle deformation, the force on the dummy and the dynamic response of the key areas in the passenger compartment.

[0073] By the above technical solution, the side impact test can be carried out to accurately impact the key areas of the vehicle passenger compartment, ensure that the collision condition highly simulates the real accident scene, and help to comprehensively evaluate the structural safety and passenger protection performance of the vehicle in the side impact. The rotating vehicle positioning platform cooperates with the high-precision encoder to accurately control the angle between the vehicle and the rigid cylinder, reduces human error, and improves the test repeatability and comparability; the three-dimensional human body positioning technology combined with the automatic adjustment of the central control system makes the impact point accurately correspond to the projection position of the key body parts of the driver, so that the stress distribution, deformation and potential injury risk of the key areas in the passenger compartment during the impact process are obtained.

[0074] The application further proposes that when the determination of the key areas of the passenger compartment is realized by the three-dimensional human body positioning technology, it includes:

[0075] The three-dimensional human body positioning technology includes a virtual cabin model constructed based on the internal space data of the test vehicle, a multi-body dynamics human body model matched with the virtual cabin model, and high-risk areas determined by finite element analysis.

[0076] In the process of determining the key areas of the passenger compartment, the internal space data of the test vehicle is obtained, including the seat layout, instrument panel position, steering wheel and airbag installation position, etc., to construct an accurate virtual cabin model that can fully reflect the vehicle internal geometric structure and space constraint conditions. The multi-body dynamics human body model is matched with the virtual cabin model, so that the position of each dummy's skeleton, joint and key organ in the model is consistent with the height, angle and posture of the space that the real passenger may occupy in the vehicle, thereby realizing high-fidelity simulation of the passenger behavior and force state. On this basis, combined with the finite element analysis method, the stress distribution, deformation response and potential injury risk of the human body model under the impact or impact are calculated and evaluated, and the areas in the passenger compartment that may produce high stress, high deformation or high risk, i.e. high-risk areas, are identified.

[0077] As a preferred embodiment, the scheme of the application is implemented as follows: in a new energy vehicle side impact test, a virtual cabin model is constructed according to the internal dimensions of the target vehicle cabin, the seat layout and the steering wheel position, accurately reflecting the internal space structure of the vehicle. A multi-body dynamics human body model is placed in the virtual cabin to simulate the normal sitting posture and body posture of the front row driver and front passenger, so that the key parts such as the head, chest and pelvis accurately correspond to the internal position of the cabin. Through finite element analysis, the stress, deformation and potential injury risk of each part of the human body model under the impact are calculated, and the high-risk areas of the driver's chest and the front passenger's head are identified. Based on these high-risk areas, the test team adjusts the rigid column to the precise position, so that the impact point corresponds to the driver's chest centroid and the front passenger's head projection position in the actual crash test, so as to truly evaluate the safety protection performance of the vehicle under side impact.

[0078] Through the above technical scheme, the application determines the key areas of the passenger compartment by using three-dimensional human body model positioning technology, which can accurately identify the parts inside the vehicle that may cause high risk to the passengers before the crash test, thereby realizing high controllability and pertinence of the crash working condition. By combining the virtual cabin model and the multi-body dynamics human body model, not only can the spatial distribution of the passengers in different sitting postures be simulated, but also the stress and deformation of each key part of the passengers under impact can be predicted through finite element analysis, thereby determining the position and size of the high-risk area.

[0079] The application further proposes that when a static load based on the proportion of the total mass is applied at a predetermined position of the new energy vehicle, it includes:

[0080] The uniform loading of the static load is realized by an electro-hydraulic servo loading system, which includes a hydraulic cylinder, a servo valve group and a pressure sensor. The pressure sensor monitors the loading force in real time and feeds back the signal to the closed-loop control system, and the closed-loop control system adjusts the opening of the servo valve group through the PID algorithm. The deformation rate of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, and when the deformation rate exceeds the preset safety threshold, the closed-loop control system immediately terminates the loading process.

[0081] The static load based on the proportion of the curb weight is applied at the preset position of the new energy vehicle, and the uniform application of the loading force is realized through an electro-hydraulic servo loading system, which is composed of a hydraulic cylinder, a servo valve group and a high-precision pressure sensor. The pressure sensor monitors the loading force in real time and feeds back the measured data to the closed-loop control system at a high speed, and the closed-loop control system continuously adjusts the opening degree of the servo valve group based on the PID algorithm to ensure that the applied force increases linearly at a preset rate and avoid instantaneous impact or nonlinear loading fluctuation. The deformation process of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, which is composed of a high-speed camera arranged at multiple angles, a digital image processing unit and a real-time deformation calculation module, and can capture the displacement changes of each key point on the roof surface in three-dimensional space. By tracking the feature points of the captured image sequence and calculating the displacement field, the roof deformation and deformation rate are accurately obtained. When the deformation rate exceeds the preset safety threshold, the closed-loop control system immediately terminates the loading process to prevent structural overload or passenger compartment damage.

[0082] As a preferred embodiment, the scheme of the application is implemented as follows: for example, when a roof crush test is performed on the roof of a compact new energy vehicle, the vehicle is fixed on a special test bench, and the center position of the roof is aligned with the hydraulic piston head of the electro-hydraulic servo loading system. The loading system is set to apply a static load of 4 times the curb weight of the vehicle, equivalent to a force of about 74kN, and the loading rate is preset to 5kN / s. The pressure sensor continuously collects load data and transmits real-time signals to the closed-loop control system, which adjusts the opening degree of the servo valve group according to the PID algorithm to ensure smooth and uniform loading. During the loading process, the high-speed stereo camera and three-dimensional optical measurement module installed on the roof surface continuously monitor the roof deformation, with a sampling frequency of 500Hz, which can capture displacement changes at the micron level. When the measured local deformation rate exceeds the safety threshold, for example, 15mm / s, the closed-loop control system automatically stops hydraulic loading to prevent local buckling of the roof structure or damage to the passenger compartment. During the entire process, the collected three-dimensional deformation data are used to analyze the overall load-bearing performance of the roof under extreme loads and can be used to optimize vehicle design and verify whether the roof safety meets the C-NCAP or Euro NCAP roof crush standard requirements.

[0083] Through the above technical scheme, the application applies a static load based on the proportion of the curb weight to accurately evaluate the load-bearing capacity of the roof structure of the new energy vehicle. The electro-hydraulic servo loading system combined with closed-loop control and the PID algorithm ensures that the loading force acts uniformly and stably on the roof of the vehicle, while the pressure sensor provides real-time feedback to ensure the accuracy and repeatability of the load application. The non-contact three-dimensional optical measurement system monitors the roof deformation rate in real time, avoiding local damage or passenger compartment damage caused by excessive deformation, thereby improving the safety and reliability of the test.

[0084] The application further proposes that the rate of roof deformation is monitored in real time by a non-contact three-dimensional optical measurement system, which includes:

[0085] The non-contact three-dimensional optical measurement system includes a multi-angle arrangement of high-speed cameras, a digital image correlation processing unit, and a real-time deformation calculation module. The real-time deformation calculation module performs feature point tracking and displacement field calculation on the image sequence captured by the high-speed camera, obtains three-dimensional deformation data of the roof surface, and calculates the deformation rate through numerical differentiation.

[0086] The rate of roof deformation is monitored in real time by a non-contact three-dimensional optical measurement system, which includes a multi-angle arrangement of high-speed cameras, a digital image correlation processing unit, and a real-time deformation calculation module. The high-speed camera synchronously captures a continuous image sequence of the vehicle roof during the loading process from multiple angles at a frequency of thousands of frames per second to ensure complete coverage of key areas on the roof surface. The digital image correlation processing unit automatically identifies and tracks feature points in the captured image sequence, and generates accurate three-dimensional displacement field data by calculating the displacement changes of feature points in consecutive frames. The real-time deformation calculation module accurately calculates the instantaneous deformation rate of each feature point based on the obtained three-dimensional displacement field through numerical differentiation, and can also generate a rate distribution map of the roof surface and a maximum deformation rate curve of key areas in real time. In addition, the deformation rate can be dynamically compared with a pre-set safety threshold, and when the deformation rate of any area exceeds the set limit, an alarm is triggered or the loading operation is terminated immediately to ensure the safety of the test process and the reliability of the data.

[0087] As a preferred embodiment, the scheme of the application is implemented as follows: for example, during the process of applying a static load based on 3 times the curb weight to the roof of a certain pure electric SUV, the test team arranges reflective marker points on the roof surface and uses four high-speed cameras to synchronously shoot from different angles around the roof. The digital image correlation processing unit tracks the displacement changes of each marker point in consecutive image frames in real time, and constructs a three-dimensional displacement field of the roof surface. Then, the real-time deformation calculation module calculates the instantaneous deformation rate of each marker point based on the three-dimensional displacement data through numerical differentiation. During the test process, it is detected that the maximum deformation rate of the center area of the roof reaches 2.8 mm / s, close to the pre-set safety threshold of 3 mm / s, and the closed-loop control system immediately records the data and prepares to terminate the loading operation to ensure test safety. Through this method, not only the deformation rate distribution of each area of the roof is accurately obtained, but also potential weaknesses in local structures can be identified in a timely manner.

[0088] By the technical scheme, the roof deformation rate is monitored in real time by using the non-contact three-dimensional optical measurement system, the three-dimensional displacement information of each area of the roof surface can be accurately and continuously obtained without interfering with the structural integrity of the test vehicle, and high-precision measurement of the instantaneous deformation rate is realized. The abnormal deformation of the local structure of the roof can be identified in time, and the closed-loop control system can take protective measures immediately when the deformation rate exceeds the preset safety threshold, preventing structural overload or local instability and improving test safety.

[0089] In summary, through the multi-dimensional scene simulation of the bottom scraping water test, the front and rear pinch collision test, the side column collision test and the roof pressure test, various extreme risk environments that new energy vehicles may encounter in real road use are comprehensively covered, and the collaborative verification of vehicle structure safety and battery system electrical safety is realized. In the bottom scraping water test, the multi-level depth gradient is dynamically adjusted by the adjustable water level control system, and combined with the modular design of the obstacle and the three-axis precise positioning platform, the repeatability of the chassis scraping condition and the controllability of the collision overlap rate are ensured; in the front and rear pinch collision test, the speed adjustment and timing management of the front and rear vehicles are realized by the independent speed control system and the high-precision time synchronization system, which can truly reproduce the time interval distribution characteristics of road continuous collision, and ensure the high fitting of the test and the actual accident environment; in the side column collision test, the key areas of the passenger compartment can be accurately locked by the rotating vehicle positioning platform and the three-dimensional human body model positioning technology, which ensures that the impact point of the rigid column corresponds to the high-risk body parts of the driver and passengers, and improves the pertinence and scientificity of the test; in the roof pressure test, the electro-hydraulic servo loading system and the non-contact three-dimensional optical measurement system are used to realize the uniform loading of static load and the real-time monitoring of roof deformation rate, and the loading can be terminated immediately when the deformation rate exceeds the preset threshold, which ensures the test safety and improves the monitoring accuracy and data reliability. During the test, the passenger compartment intrusion amount, the door opening performance, the battery system insulation resistance state, the electrolyte leakage situation, the thermal runaway risk and the head force are monitored, and the overall coverage of vehicle structure safety, electrical safety and occupant protection performance is realized. The multi-dimensional weighted scoring system is used to standardize and weight the test results of the four types, which can objectively generate a unified safety performance comprehensive score, and divide it into four levels of excellent, good, qualified and unqualified, which not only enhances the comparability and universality of the results, but also provides a unified basis for safety performance evaluation of different vehicle models.

[0090] Those skilled in the art will appreciate that embodiments of the application can be supplied as a method, a system or a computer program product. Accordingly, the application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the application can be embodied in the form of a computer program product on one or more computer readable storage media (including, without limitation, magnetic disks; optical disks; magneto-optical disks; ROMs; flash memory; etc.) having computer usable program code embodied therein.

[0091] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks in the flowcharts and / or combination thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flowchart block or blocks.

[0092] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks in the flowcharts and / or combination thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flowchart block or blocks.

[0093] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks in the flowcharts and / or combination thereof. These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flowchart block or blocks.

[0094] Finally, it should be noted that the above-described embodiments are merely intended for describing and illustrating, not limiting, the technical solution of the present application. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. A new energy vehicle extreme working condition collision safety test method, characterized in that, The method comprises: Performing a bottom scraping test by controlling the new energy vehicle to pass through a preset depth of a water area at a preset speed, and making the chassis collide with a preset size of an obstacle at a preset overlap rate, monitoring the battery state parameters of the battery system in real time, and determining the battery safety performance according to the preset battery standard parameters; Performing a front and rear pinch collision test by making the new energy vehicle simultaneously suffer continuous collision impact from the front and rear trolleys, detecting the passenger compartment state parameters, and determining the vehicle structure safety according to the preset passenger compartment standard parameters; Performing a side column collision test by making the new energy vehicle collide with a preset size of a rigid cylinder at a preset speed and a preset angle, the collision position being located in a key area of the passenger compartment, monitoring the key area state parameters, and determining the vehicle structure safety according to the key area standard parameters; Performing a roof pressing test by applying a static load based on the proportion of the curb weight at a preset position of the new energy vehicle, measuring the roof deformation and the force value of the passenger head model, and determining the driver cabin structure safety according to the preset roof deformation threshold and head pressure threshold; Based on the comprehensive evaluation results of the four tests, a multi-dimensional weighted scoring system is used to calculate the safety performance score, the multi-dimensional weighted scoring system converts each test index into a standardized score, allocates weight coefficients according to the importance of each index, and obtains the total safety performance score by weighted summation; The safety performance score is divided into excellent, good, qualified and unqualified four levels according to the preset interval threshold.

2. The method according to claim 1, wherein, When the new energy vehicle passes through a preset depth of a water area at a preset speed, it includes: The preset depth of the water area realizes multi-depth gradient through an adjustable water level control system, the adjustable water level control system includes a liquid level sensor and an electric regulating valve group, the liquid level sensor monitors the water level in real time and transmits the signal to the central controller, the central controller adjusts the opening of the electric regulating valve group according to the preset test scheme, realizes the accurate control of the depth of the water area, and the multi-depth gradient is dynamically generated according to the ground clearance parameters of the target test vehicle to simulate the chassis scraping scene when the vehicle continuously drives on different water depth road sections.

3. The method according to claim 2, wherein, When the chassis collides with a preset size of an obstacle at a preset overlap rate, it includes: The preset size of the obstacle includes replaceable spherical obstacle modules and trapezoidal obstacle modules, the obstacle is fixed at the bottom of the water pool through a precise positioning platform, the precise positioning platform includes a three-axis displacement mechanism, the relative position of the obstacle and the test vehicle chassis is calibrated through a laser range finder to ensure that the collision overlap rate is controlled within a preset range; The hardness of the obstacle is measured by a Shore hardness tester and controlled within a preset range to match the characteristics of the obstacle in different road scenes.

4. The method according to claim 3, wherein, When the new energy vehicle simultaneously suffers continuous collision impact from the front and rear trolleys, it includes: The collision speed of the front trolley and the rear trolley is dynamically adjusted by an independent speed control system, the speed control system comprises an encoder and a variable frequency driving motor, the encoder monitors the trolley speed in real time and feeds back a signal to a motion controller, and the motion controller adjusts the output power of the variable frequency driving motor through a PID algorithm; The collision time sequence of the two trolleys is managed by a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within a preset range.

5. The method according to claim 4, wherein, When the collision time sequence of the two trolleys is managed by a high-precision time synchronization system, so that the time interval of the front and rear collisions is controlled within a preset range, comprising: The high-precision time synchronization system comprises a GPS time module installed on each trolley, a central timing controller, and a wireless communication unit; the central timing controller generates a collision time sequence conforming to the statistical law based on the distribution characteristics of the time interval of the continuous collision in the actual road traffic accident database, and sends accurate start instructions to each trolley through the wireless communication unit, so that the time interval of the front and rear collisions is controlled within a preset range.

6. The method according to claim 5, wherein, When the new energy vehicle collides with a rigid cylinder of a preset size at a preset speed and a preset included angle, and the impact position is located in the key area of the passenger compartment, comprising: The range of the preset included angle is achieved by a rotary vehicle positioning platform, the rotary vehicle positioning platform comprises a rotatable circular turntable and an angle feedback system; the angle feedback system is composed of a high-precision encoder, which monitors the included angle between the test vehicle and the rigid cylinder in real time; the determination of the key area of the passenger compartment is achieved by three-dimensional human body model positioning technology, and the central control system automatically adjusts the horizontal position and height of the rigid cylinder according to the calculation result of the high-risk area, so that the impact point accurately corresponds to the projection position of the driver's key body part in the vehicle coordinate system.

7. The method according to claim 6, wherein, When the determination of the key area of the passenger compartment is achieved by three-dimensional human body model positioning technology, comprising: The three-dimensional human body model positioning technology comprises a virtual cabin model constructed based on the internal space data of the test vehicle, a multi-body dynamics human body model matched with the virtual cabin model, and the high-risk area determined by finite element analysis.

8. The method according to claim 7, wherein, When a static load based on the proportion of the gross weight is applied to the new energy vehicle at a preset position, comprising: The uniform speed loading of the static load is achieved by an electro-hydraulic servo loading system, the electro-hydraulic servo loading system comprises a hydraulic cylinder, a servo valve group and a pressure sensor; the pressure sensor monitors the loading force in real time and feeds back a signal to a closed-loop control system, and the closed-loop control system adjusts the opening degree of the servo valve group through a PID algorithm; the deformation rate of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, and when the deformation rate exceeds a preset safety threshold, the closed-loop control system immediately terminates the loading process.

9. The method according to claim 8, wherein, When the deformation rate of the roof is monitored in real time by a non-contact three-dimensional optical measurement system, comprising: The non-contact three-dimensional optical measurement system comprises a multi-angle arrangement of high-speed cameras, a digital image correlation processing unit and a real-time deformation calculation module; the real-time deformation calculation module performs feature point tracking and displacement field calculation on an image sequence captured by the high-speed cameras, obtains three-dimensional deformation data of a roof surface, and calculates a deformation rate through a numerical differentiation method.

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