Test method for road durability examination of powertrain on a drum test bench

Abstract

The test method for road durability examination of a power assembly on a drum test bed belongs to the field of automobile test technology.The method comprises the following steps: test preparation;collecting road spectrum information of a test vehicle;compiling a standard and parameters of the drum test bed for simulating durability examination according to the collected road spectrum information;installing the test vehicle on the drum test bed and installing a drum driving robot;carrying out examination working condition simulation according to the parameters of the drum test bed for durability examination compiled by S3;after the examination is completed, disassembling the power assembly and judging the power assembly. The application can simulate the durability performance of the power assembly under different environmental conditions under the whole vehicle condition, broaden the prediction range of the test, understand the performance of the power assembly performance parts under different conditions in advance, and improve the test efficiency. The application overcomes the limitations of the traditional actual road test by simulating the actual whole vehicle road condition on the drum for durability examination.

Description

TECHNICAL FIELD

[0001] The present application relates to a test method for road durability test of powertrain on a drum test bench, belonging to the field of automobile test technology. BACKGROUND

[0002] Traditional actual road durability test, as a key means to evaluate the performance of vehicles under various environmental conditions, has long been facing many challenges. Such tests usually require vehicles to experience various natural environments and road conditions during long-time and long-distance driving to comprehensively evaluate their durability and reliability. However, this testing method has exposed many shortcomings in actual operation.

[0003] Firstly, the change of natural environment has a significant impact on actual road durability test. The temperature fluctuation caused by seasonal change and the slippery road surface caused by rain and snow weather may not only cause the test to be interrupted, but also may cause the test results to be biased, which cannot accurately reflect the real performance of the vehicle. This uncertainty not only prolongs the test period, but also reduces the test efficiency and increases the test cost.

[0004] Secondly, there are difficulties in standardization of actual road test. Due to the complexity and variability of actual road conditions, it is difficult to achieve uniformity and standardization of test conditions, which leads to doubts about the repeatability and reliability of test results. Different test batches may produce completely different results due to differences in road conditions, weather conditions and other factors, making it difficult to use test results as reliable evaluation basis.

[0005] In addition, actual road test is also accompanied by high safety risk. During long-time driving, vehicles may lose control due to failure of non-test components, posing a threat to test personnel and the surrounding environment. This safety risk not only increases the complexity of the test, but also limits the scope and frequency of the test.

[0006] Finally, considering the influence of production consistency on vehicle durability performance, traditional actual road durability test requires at least three vehicles to be tested simultaneously to ensure the accuracy of the test. This not only increases the number of vehicles required for testing and the cost, but also doubles the cost and risk factor of durability test. These unfavorable factors have a serious impact on the progress and cost control of the test.

[0007] Therefore, it is an urgent need for the automobile industry to seek a more efficient, accurate and safe testing method. SUMMARY

[0008] To solve the problems in the background art, the present application provides a test method for road durability test of powertrain on a drum test bench.

[0009] To achieve the above object, the present application adopts the following technical solution: a test method for road durability examination of a power assembly on a rotating drum test bench, the method comprising the following steps:

[0010] S1: preparation before test;

[0011] S101: adaptive mounting of the power assembly;

[0012] S102: adaptive matching optimization between the vehicle state and the power assembly and the vehicle;

[0013] S103: installation of sensors required for durability examination on the test vehicle;

[0014] S104: safety and comprehensive performance inspection of the test vehicle.

[0015] S2: collection of road profile information for durability test of the test vehicle;

[0016] The road profile information is obtained by transporting the test vehicle to a durability test site and collecting it according to the durability test conditions, or it is obtained by calculating the road profile information of a similar vehicle through engine speed and transmission speed ratio parameters.

[0017] The calculation process is as follows:

[0018] Case 1:

[0019] If the similar parameters of the test vehicle and the similar vehicle exceed the predetermined settings, the road profile information of the similar vehicle is directly applied;

[0020] Case 2:

[0021] If the similar parameters of the test vehicle and the similar vehicle do not exceed the predetermined settings, the difference between the engine speeds is calculated through the difference ratio of the transmission speed ratio. The changed engine speed is used as the road profile information of the test vehicle; the specific process of calculating the difference between the engine speeds through the difference ratio of the transmission speed ratio is as follows:

[0022] Step 1: calculate the wheel speed under a specific gear:

[0023] Wheel speed = engine speed / transmission speed ratio

[0024] Step 2: select two different gears, calculate the corresponding wheel speeds and the difference between the two wheel speeds;

[0025] Step 3: calculate the engine speed difference through the wheel speed difference

[0026] Engine speed difference =

[0027] Wheel speed difference x transmission speed ratio (higher gear) / transmission speed ratio (lower gear).

[0028] The road spectrum information at least includes engine speed, engine output power, throttle pedal opening, transmission clutch state, gear, output speed and output power of the powertrain at continuous time.

[0029] S3: According to the collected road spectrum information, the standards and parameters of the drum test bench simulation durability test are prepared;

[0030] S301: According to the collected road spectrum information, the resistance to be simulated during the drum test is determined

[0031] S302: The current powertrain working state is confirmed through the engine speed and gear information

[0032] S303: According to the throttle opening, the load condition of the engine is confirmed

[0033] S304: The vehicle speed is used as a stability index to balance the power generated by the vehicle and the power absorbed by the drum, so as to confirm the standards and parameters of the drum test bench simulation durability test.

[0034] S4: Install the test vehicle on the drum test bench and install the drum driving robot;

[0035] S5: According to the parameters of the drum test bench durability test prepared in S3, the test condition simulation is carried out;

[0036] S501: The test condition is divided into multiple test condition sections according to power load, including urban test condition section, suburban test condition section, high-speed test condition section and extreme test condition section;

[0037] S502: According to the temperature condition, each test condition section is further divided into-7℃, 25℃ and 40℃ three temperature test sections;

[0038] S503: According to the vehicle load, each temperature test section is divided into empty load, half load and full load three load test sections;

[0039] S504: Combined with the above test condition section, temperature test section and load test section, multiple actual test conditions are formed;

[0040] S505: According to the positioning requirements of the vehicle use characteristics, the number of repetitions of each actual test condition is selected for durability test;

[0041] S506: After completing the test of all actual test conditions, according to the actual state of the powertrain, corresponding actual test conditions are added for further durability test.

[0042] S6: After the test is completed, the powertrain is disassembled and judged.

[0043] Compared with the prior art, the present application has the beneficial effects that:

[0044] 1、The present application can simulate the durability performance of the powertrain under different environmental conditions in the whole vehicle condition, broaden the prediction range of the test, and understand the performance of the powertrain performance components under different conditions in advance, thereby improving the test efficiency. In addition, by simulating the actual whole vehicle road condition on the drum for durability test, the limitations of traditional actual road test are overcome, the product development cycle is shortened, and the automobile manufacturers can quickly put high-quality products into the market.

[0045] 2、The present application carries out whole vehicle durability simulation test through a specific test platform vehicle, reduces the probability of risks occurring in the durability test process, and ensures the safety and reliability of the test; the whole vehicle driving is carried out by using a driving robot, the test data out-of-tolerance or misoperation caused by driver fatigue is avoided, the consistency and comparability of each test are ensured, and reliable data support is provided for continuous improvement of product quality. DETAILED DESCRIPTION

[0046] The technical solutions in the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0047] The drum test bench is a device that can simulate the driving state of a vehicle under laboratory conditions. It can provide a stable and repeatable test environment, including road conditions and environmental conditions such as light and temperature, and is not affected by external weather and road conditions. By precisely controlling the speed, acceleration / deceleration mode, slope simulation and other factors of the drum, the load conditions of the vehicle under different working conditions can be more realistically reproduced, thereby achieving comprehensive evaluation of the powertrain system. In addition, by using advanced sensor technology and data processing algorithms, various performance indicators of the vehicle can be monitored in real time during the drum test, such as engine output power, gearbox shift smoothness, brake system response time, etc., thereby improving the accuracy of the test results.

[0048] The present application is a test method for road durability test of a powertrain on a drum test bench, which comprises the following steps:

[0049] S1: preparation before test;

[0050] S101: selecting a corresponding test vehicle according to the powertrain to be tested, and mounting the powertrain to be tested on the whole vehicle driving platform of the corresponding test vehicle for powertrain adaptability mounting;

[0051] S102: Adaptively match and optimize the whole vehicle state and the power assembly and the whole vehicle, to ensure that the test vehicle can successfully complete the WLTC test and can reach the emission standard of the corresponding vehicle model;

[0052] S103: Install the sensors required for durability test on the test vehicle, including transmission oil pressure sensor, exhaust temperature sensor, output shaft torque sensor, etc.

[0053] S104: Check the safety and comprehensive performance of the test vehicle.

[0054] S2: Collect the road spectrum information of the test vehicle for durability test;

[0055] To ensure the accuracy of the test, the road spectrum information is obtained by transporting the test vehicle to the durability test site and collecting it according to the durability test conditions, or by calculating it from the engine speed and transmission speed ratio parameters of the road spectrum information of other similar vehicle models in the past.

[0056] The calculation process is as follows:

[0057] Case one:

[0058] If the similar parameters of the test vehicle and the similar vehicle model exceed the predetermined settings (such as the engine is a 1.6L engine, the transmission is a main reduction ratio of 3.414-3.722, the speed ratio of each gear is not much different, and the whole vehicle test mass is between 1.5t-1.7t), the road spectrum information of the similar vehicle model is directly applied;

[0059] Case two:

[0060] If the similar parameters of the test vehicle and the similar vehicle model do not exceed the predetermined settings, the difference between the engine speeds is calculated by the difference ratio of the transmission speed ratio. The changed engine speed is used as the road spectrum information of the test vehicle; the specific process of calculating the difference between the engine speeds by the difference ratio of the transmission speed ratio is as follows:

[0061] Step one: Calculate the wheel speed under a specific gear:

[0062] Wheel speed = Engine speed / Transmission speed ratio

[0063] For a given transmission, each gear has a fixed speed ratio, which can usually be found in the technical parameter table of the vehicle or by consulting the relevant information of the transmission.

[0064] Step two: Select two different gears and calculate the corresponding wheel speeds and the difference between the two wheel speeds;

[0065] Step three: Calculate the engine speed difference by the wheel speed difference

[0066] Engine speed difference = Engine speed of the test vehicle - Engine speed of the reference vehicle

[0067] Wheel speed difference x Transmission speed ratio (higher gear) / Transmission speed ratio (lower gear)

[0068] The difference in the mass of the vehicle during the test is an indicator of the acceleration performance of the vehicle. The difference in acceleration can be calculated according to the known formula F = Ma, and the acceleration time can be increased appropriately in the drum test.

[0069] The road profile information at least includes the engine speed, engine output power, throttle pedal opening, transmission clutch state, gear, output speed, and output power of the powertrain at consecutive times.

[0070] S3: According to the collected road profile information, the standards and parameters for simulating the durability test on the drum test bench are prepared.

[0071] S301: According to the collected road profile information, the resistance to be simulated during the drum test is determined

[0072] S302: The current powertrain working state is confirmed through the engine speed and gear information

[0073] S303: The engine load is confirmed according to the throttle opening

[0074] S304: The vehicle speed is used as a stability indicator to balance the power output by the vehicle and the power absorbed by the drum, thereby confirming the standards and parameters for simulating the durability test on the drum test bench.

[0075] S4: The test vehicle is installed on the drum test bench, and a drum driving robot is installed for the operation of the throttle pedal, brake pedal, and gear handle during the durability test, which improves efficiency, reduces safety risks for personnel, and improves test accuracy.

[0076] S5: The test conditions are simulated according to the parameters for the durability test on the drum test bench prepared in S3.

[0077] S501: The test conditions are divided into multiple test section intervals according to the power load, including urban test section, suburban test section, high-speed test section, and extreme test section.

[0078] S502: Each test section interval is further divided into three temperature test intervals of -7°C, 25°C, and 40°C according to the temperature conditions.

[0079] S503: Each temperature test interval is divided into three load test intervals of empty load, half load, and full load according to the vehicle load.

[0080] S504: In combination with the above-mentioned working condition section evaluation interval, temperature evaluation interval and load evaluation interval, a plurality of actual evaluation working conditions are formed;

[0081] S505: According to the positioning requirements of the vehicle use characteristics, the number of repetitions of each actual evaluation working condition is selected for durability evaluation;

[0082] S506: After completing the evaluation of all actual evaluation working conditions, according to the actual state of the powertrain, corresponding actual evaluation working conditions are added for further durability testing.

[0083] S6: After the evaluation is completed, the powertrain is disassembled and judged.

[0084] It is apparent to those skilled in the art that the present application is not limited to the details of the foregoing exemplary embodiments, and that the present application can be implemented in other forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the present application should be defined by the appended claims rather than the above description, and it is intended to include all changes falling within the meaning and scope of equivalents of the claims.

[0085] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A test method for road durability proving of a powertrain on a roller test bench, characterized in that: The method comprises the following steps: S1: preparation before test; S2: collecting road spectrum information of the test vehicle for endurance test; The road spectrum information is obtained by calculating the engine speed and the transmission speed ratio parameters based on the road spectrum information of the similar vehicle model; The road spectrum information calculation process is as follows: Case one: If the similar parameters of the test vehicle and the similar vehicle model exceed the predetermined setting, the road spectrum information of the similar vehicle model is directly applied; Case two: If the similar parameters of the test vehicle and the similar vehicle model do not exceed the predetermined setting, the difference between the engine speeds is calculated by the difference ratio of the transmission speed ratio, and the changed engine speed is used as the road spectrum information of the test vehicle; the specific process of calculating the difference between the engine speeds by the difference ratio of the transmission speed ratio is as follows: Step one: calculate the wheel speed under a specific gear: Wheel speed = engine speed / transmission speed ratio Step two: select two different gears, calculate the corresponding wheel speeds and the difference between the two wheel speeds; Step three: calculate the engine speed difference by the wheel speed difference Engine speed difference = wheel speed difference x transmission speed ratio of higher gear / transmission speed ratio of lower gear; S3: prepare the standard and parameters of the drum test bench simulation endurance test according to the collected road spectrum information; S4: install the test vehicle on the drum test bench and install the drum driving robot; S5: simulate the test condition according to the parameters of the drum test bench endurance test prepared in S3; S6: after the test is completed, the powertrain is disassembled and judged. The S1 comprises the following steps:

2. A test method for road durability examination of a power assembly on a test bench of a rotating drum, according to claim 1, characterized in that: S101: perform powertrain adaptive loading; S102: adaptively match and optimize the vehicle state and the powertrain and the vehicle; S103: install the sensors required for endurance test on the test vehicle; S104: check the safety and comprehensive performance of the test vehicle. The road spectrum information in S2 is obtained by transporting the test vehicle to the endurance test site and collecting it according to the endurance test conditions.

3. A test method for road durability examination of a power assembly on a test bench of a rotating drum, according to claim 2, characterized in that: The road spectrum information at least includes the engine speed, engine output power, throttle pedal opening, transmission clutch state, gear, output speed and output power of the powertrain in continuous time.

4. A test method for road durability examination of a power assembly on a test bench of a rotating drum, according to claim 3, characterized in that: The S3 comprises the following steps:

5. The test method for road durability examination of a power assembly on a test bench in accordance with claim 1, characterized in that: S301: determine the resistance to be simulated during drum test according to the collected road spectrum information S302: confirm the current powertrain working state through engine speed and gear information S303: confirm the engine load according to the throttle opening S304: vehicle speed as a stability index is used to balance the power generated by the vehicle and the power absorbed by the drum, so as to confirm the standard and parameters of the drum test bench simulation endurance test. The S5 comprises the following steps:

6. The test method for road durability examination of a power assembly on a test bench in accordance with claim 1, characterized in that: S501: divide the test condition into multiple condition section test intervals according to power load, including urban condition section, suburban condition section, high-speed condition section and extreme condition section; S502: further subdivide each condition section test interval into-7℃, 25℃ and 40℃ temperature test intervals according to temperature conditions; S503: divide each temperature test interval into empty load, half load and full load three load test intervals according to vehicle load. ​ S504: In combination with the above-mentioned working condition section evaluation interval, temperature evaluation interval and load evaluation interval, a plurality of actual evaluation working conditions are formed; S505: According to the positioning requirements of the vehicle use characteristics, the number of repetitions of each actual evaluation working condition is selected for durability evaluation; S506: After completing the evaluation of all actual evaluation working conditions, according to the actual state of the powertrain, corresponding actual evaluation working conditions are added for further durability test.