CN-121977851-A - Method and equipment for testing exhaust performance of automobile coolant loop

CN121977851ACN 121977851 ACN121977851 ACN 121977851ACN-121977851-A

Abstract

The invention belongs to the technical field of automobile thermal management system testing, and particularly relates to an automobile coolant loop exhaust performance testing method, which comprises the steps of firstly building a testing system comprising a tested loop, a mounting rack capable of being adjusted in multiple degrees of freedom, automatic filling and emptying equipment, a multi-mode monitoring unit and a data processing control system; the method comprises the steps of presetting standard, univariate, multivariable and extreme working conditions, collecting multi-mode data such as images, lasers, pressures, exhaust parameters and the like, inputting an improved YOLOv bubble aggregation recognition model containing a small target detection head and a time sequence correlation layer after pretreatment and weighted fusion to generate an aggregation result, and finally, weighting and calculating standardized data through an exhaust performance evaluation model to output an evaluation result and an optimization suggestion. The invention can solve the technical problems of inflexible adjustment of the space attitude of the parts, difficult control of the test variable and inaccurate monitoring of the exhaust process in the prior art.

Inventors

ZHAO DONGPENG
ZHANG HAOQI
XU LEI
WANG QINGYANG
LONG HAISHENG
SHI FENG
WANG WEIXING
HONG RUI

Assignees

中国汽车工程研究院股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (9)

1. The method for testing the exhaust performance of the automobile coolant loop is characterized by comprising the following steps of: S1, building an exhaust performance test system of an automobile coolant loop according to parameters of the automobile coolant loop to be tested, wherein the system comprises a tested coolant loop, a coolant loop mounting rack, automatic coolant filling and emptying equipment, a monitoring unit, an auxiliary power supply system and a data processing control system; s2, presetting a test working condition, setting working condition parameters for testing the exhaust performance of the cooling liquid loop according to the test working condition, and calling a monitoring unit to acquire multi-mode data of the exhaust of the cooling liquid loop in the test process; S3, calling a preset multi-mode fusion bubble aggregation recognition model to recognize bubble aggregation conditions in the image data according to the acquired multi-mode data of the exhaust of the cooling liquid loop, and generating a bubble aggregation result; and S4, calling an exhaust performance evaluation model according to the exhaust parameter data and the bubble aggregation result to evaluate the exhaust performance of the cooling liquid loop, and outputting an evaluation result.
2. The method for testing the exhaust performance of the automobile coolant circuit according to claim 1, wherein S3 comprises: s3-1, acquiring multi-mode data consisting of image data, laser data and pressure data of a cooling liquid loop in a test working condition; S3-2, performing self-adaptive histogram equalization processing, canny edge detection processing and semantic segmentation processing on the image data in the multi-mode data, performing denoising processing and bubble diameter calculation on the laser data, performing filtering and fast Fourier transformation processing on the pressure data, outputting the processed image data, laser data and pressure data, and performing weighted fusion on the processed image data, the laser data and the pressure data to generate fused data; s3-3, constructing a multi-mode fusion bubble aggregation recognition model based on the improved YOLOv network, inputting the fused data into the multi-mode fusion bubble aggregation recognition model, and outputting a bubble aggregation result.
3. The method for testing the exhaust performance of the automobile coolant loop according to claim 2, wherein in the step S3-3, the construction of the multi-mode fusion bubble aggregation recognition model based on the improved YOLOv network is specifically as follows: A small target detection head is additionally arranged behind a YOLOv network neck network and in front of a head network, a time sequence correlation layer arranged behind a YOLOv network is additionally arranged, and a loss function expression of the small target detection head is as follows: Wherein, the The loss value is detected for a small target, In order to achieve the loss of the cross-over ratio, Loss of confidence for the target; the same bubble in the adjacent frames is associated by the time sequence association layer to obtain an association cost matrix, and the expression is as follows: Wherein, the The associated cost for the ith bubble of the t-1 frame and the jth bubble of the t-1 frame; Is a two-needle bubble boundary frame And (3) with Representing the position similarity; The diameter of the ith bubble for the t-th frame; the diameter of the ith bubble for the t-1 th frame; The average diameter of the bubbles in the test scene is obtained based on the historical data.
4. The method for testing the exhaust performance of the automobile coolant loop according to claim 3, wherein S3-3 inputs the fused data into a multi-modal fused bubble aggregation recognition model, and outputs a bubble aggregation result specifically as follows: The multi-mode fusion bubble aggregation recognition model outputs a concentration result, a bubble residence time result and a pressure fluctuation amplitude of bubbles, and outputs a bubble aggregation level according to a bubble concentration threshold, a bubble residence time threshold and a pressure fluctuation threshold, wherein the expression is as follows: Wherein, the In order to aggregate the levels of the hierarchy, In order to achieve the concentration of the air bubbles, 、、 Is a bubble concentration threshold; For the air bubble residence time, 、、 Is a bubble residence time threshold; the pressure fluctuation amplitude is calculated by the maximum value and the minimum value of the filtered pressure; 、、 Is the pressure fluctuation threshold.
5. The method for testing the exhaust performance of the automobile coolant circuit according to claim 1, wherein S1 comprises the following steps: S1-1, constructing a tested cooling liquid loop according to parts of the cooling liquid loop of the real vehicle to be tested and a connecting pipeline structure, and installing the tested cooling liquid loop on a cooling liquid loop installing bench; S1-2, automatically filling and rapidly emptying the cooling liquid in the tested cooling liquid loop through cooling liquid automatic filling and emptying equipment; S1-3, aligning a bubble monitoring component in a monitoring unit with a key point of a cooling liquid loop, arranging a cooling liquid parameter monitoring component in the monitoring unit in a tested cooling liquid loop and cooling liquid automatic filling and emptying equipment, and arranging a part position and an attitude monitoring component in the monitoring unit at a key part position of a cooling liquid loop mounting bench; S1-4, providing working power for the equipment through an auxiliary power system, and connecting a data processing control system with the equipment to obtain equipment control and running states and perform data processing.
6. The method for testing the exhaust performance of the cooling liquid circuit of the automobile according to claim 5, wherein the cooling liquid circuit mounting rack in S1-1 comprises an outer supporting frame, a first direction sliding rail, a second direction sliding rail, a third direction adjusting base unit, an in-plane rotating base unit and a part mounting unit which are mounted on the outer supporting frame, and the method is characterized in that: The first direction sliding rail moves along the X-axis direction of the outer support frame, and the second direction sliding rail is arranged on the first direction sliding rail and moves along the Y-axis direction of the outer support frame; the third direction adjusting base unit is arranged on the second direction sliding rail and moves along the Z axis of the outer supporting frame; the in-plane rotating base unit is arranged on the third direction adjusting base unit to realize free rotation in a plane formed by the X direction and the Y direction; the part mounting unit mounts the measured coolant circuit.
7. The method for testing the exhaust performance of the automobile coolant circuit according to claim 6, wherein S2 comprises: S2-1, constructing a standard working condition test, a univariate posture adjustment test, a multivariate posture adjustment test and an extreme working condition test; S2-2, acquiring image data of a key area of a cooling liquid loop through a camera unit of the bubble monitoring assembly in the test process, acquiring scattering signals through the laser transmitter unit and the receiver unit in the bubble monitoring assembly which are arranged on two sides of a pipeline in pairs, and acquiring laser data; S2-3, collecting exhaust parameter data in the tested cooling liquid loop and the automatic cooling liquid filling and emptying equipment through a cooling liquid parameter monitoring component in the monitoring unit; S2-4, integrating the image data, the laser data, the pressure data and the exhaust parameter data to generate multi-mode data.
8. The method for testing the exhaust performance of the automobile coolant circuit according to claim 7, wherein S4 comprises: S4-1, carrying out standardization processing on the exhaust parameter data and the bubble aggregation result to obtain standardized processed data; s4-2, constructing an exhaust performance evaluation model, and carrying out working condition self-adaptive weighted calculation on the standardized data through the exhaust performance evaluation model to obtain an exhaust performance comprehensive score.
9. An automobile coolant loop exhaust performance test device, which is applied to the automobile coolant loop exhaust performance test method according to any one of claims 1-8, is characterized by comprising a tested coolant loop, a coolant loop mounting rack, a coolant automatic filling and emptying device, a monitoring unit, an auxiliary power supply system and a data processing control system, wherein: The automatic filling and emptying device for the cooling liquid is used for automatically filling and rapidly emptying the cooling liquid in the cooling liquid loop to be tested; the monitoring unit comprises a bubble monitoring component, a cooling liquid parameter monitoring component and a part position and posture monitoring component, wherein the bubble monitoring component is aligned to a key point of a cooling liquid loop; the auxiliary power system is used for supplying power to the equipment, and the data processing control system is connected with the equipment to acquire equipment control, running state and data processing.

Description

Method and equipment for testing exhaust performance of automobile coolant loop Technical Field The invention belongs to the technical field of automobile thermal management system testing, and particularly relates to an automobile coolant loop exhaust performance testing method and equipment. Background The automobile cooling liquid loop is a key heat management unit for ensuring the normal operation of core components such as an engine, a power battery (a new energy automobile), an air conditioning system and the like, and has the core functions of realizing the absorption, the transmission and the emission of heat through the circulating flow of cooling liquid and maintaining each component in an optimal working temperature range. However, in the process of assembly, maintenance or working condition change, the cooling liquid loop is extremely easy to introduce air due to factors such as poor sealing, improper cooling liquid supplementing operation, loop structural design defect and the like, so that air resistance or bubble accumulation is formed. The residual air can have various negative effects on the working performance of a cooling liquid loop, namely firstly, the heat conductivity coefficient of the air is far lower than that of the cooling liquid, a heat resistance is formed in a bubble accumulation area, the heat dissipation of a local part is poor, the problems of overheating of an engine, rise of thermal runaway risk of a power battery, reduction of refrigerating/heating efficiency of an air conditioner and the like are caused, secondly, the residual air can perform oxidation reaction with the cooling liquid and the metal wall surface of the loop when circularly flowing in the loop, the degradation of the cooling liquid and the corrosion of the loop parts are accelerated, the service life of the loop is shortened, thirdly, the air resistance can cause the fluctuation of the circulation flow of the cooling liquid, the control precision of a thermal management system is influenced, meanwhile, noise can be generated, and the NVH performance of an automobile is influenced. Therefore, the cooling liquid loop is ensured to have excellent exhaust performance, and the air in the loop is rapidly and thoroughly exhausted, so that the cooling liquid loop is one of core indexes in the design and verification process of the automobile thermal management system. At present, the test method for the exhaust performance of the cooling liquid loop in the automobile industry is mainly divided into two types, namely, a real automobile working condition test is carried out, namely, the exhaust performance is evaluated by placing the whole automobile under different environment temperatures and different running working conditions (such as idling, acceleration and climbing), and monitoring the pressure and temperature change of the loop and the change of the liquid level in an expansion kettle. The method can reflect the actual use situation, but has the problems of long test period, high cost, difficult accurate control of working condition variables (such as ambient temperature and fluctuation of gradient of a running road surface) and the like, and cannot separate the influence of the space posture of a certain part on the exhaust performance and difficult to locate the source of the exhaust problem, and the other method is bench simulation test, namely, a cooling liquid loop simulation bench is built, loop core parts (such as a water pump, a radiator, an expansion kettle, a water valve, a pipeline joint and the like) are fixedly installed according to the design position of an actual vehicle, cooling liquid is introduced, the working pressure and the working temperature of the loop are simulated, and the exhaust effect is monitored. However, the existing bench simulation test equipment has the obvious technical defects that the base of the existing test bench is of a fixed structure, the mounting bracket of each part can only realize limited height adjustment (such as hierarchical adjustment through bolt hole positions) or cannot be adjusted, the angle adjustment function is generally lost, the space height and the mounting angle of a single part or a plurality of parts cannot be flexibly and continuously changed in the test process, and the influence of different part mounting postures on the exhaust effect of a loop is difficult to study. For example, the installed height of the expansion tank directly affects the static pressure distribution of the loop, the height deviation of the expansion tank can lead to the exhaust port being lower than the highest point of the loop, so that air cannot be exhausted, and the inclination angle of the radiator can change the flow path of cooling liquid in the radiating core, so that bubbles are accumulated at the top of the core. The existing fixed rack cannot accurately reproduce the variables, so that a large deviation exists between a test result and actual exhaust perf