Engine body vibration evaluation method and device and vehicle

Abstract

The invention relates to the technical field of engine body vibration, in particular to an engine body vibration evaluation method and device and a vehicle, and the method comprises the steps: obtaining a target test working condition of an engine, and determining a target test strategy according to the target test working condition; the engine is tested according to the target test strategy, a crankshaft rotating speed pulse signal in the engine test process is obtained, and the crankshaft rotating speed pulse signal is converted into a transient angular speed signal; a vibration signal is filtered out from the transient angular velocity signal, a rotation angle fluctuation angle signal of the engine is obtained according to vibration signal integration, a reference angle value is determined according to a target test working condition, and a body vibration evaluation result of the engine is determined according to an angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value. Therefore, the problems of low evaluation efficiency, poor accuracy and the like when the vibration of the engine body is evaluated in a rack test mode in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine body vibration, and particularly relates to an engine body vibration evaluation method and device and a vehicle. BACKGROUND

[0002] An engine is a main source of vibration and noise of a vehicle, and NVH (Noise, Vibration and Harshness) quality directly affects the perception of people in the vehicle. Engine body vibration and noise optimization under a fixed vehicle working condition is paid more and more attention.

[0003] In the related art, a separate bench is established to perform vibration testing, and vibration acceleration and other indicators are used for research. However, in the related art, the engine body vibration is evaluated by the bench testing method, and there are problems such as low evaluation efficiency and poor accuracy. SUMMARY

[0004] The present application provides an engine body vibration evaluation method and device and a vehicle to solve the problem that the engine body vibration is evaluated by the bench testing method in the related art, and there are problems such as low evaluation efficiency and poor accuracy.

[0005] The first aspect of the present application provides an engine body vibration evaluation method, comprising the following steps: obtaining a target test working condition of an engine, determining a target test strategy according to the target test working condition; testing the engine according to the target test strategy, obtaining a crankshaft speed pulse signal in the test process of the engine, and converting the crankshaft speed pulse signal into a transient angular velocity signal; filtering a vibration signal from the transient angular velocity signal, obtaining a rotation angle fluctuation angle signal of the engine by integrating the vibration signal, determining a reference angle value according to the target test working condition, and determining a body vibration evaluation result of the engine according to an angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value.

[0006] Optionally, the target test strategy is determined according to the target test working condition, comprising: obtaining a first correspondence table of the target test working condition and the target test strategy; and querying the first correspondence table to obtain the target test strategy with the target test working condition as an index.

[0007] Optionally, the target test working condition comprises a cold start working condition and a hot idle working condition, the target test strategy corresponding to the cold start working condition is a first test strategy, and the target test strategy corresponding to the hot idle working condition is a second test strategy.

[0008] Optionally, the first test strategy comprises: placing a test vehicle in a test environment within a target temperature range; placing the test vehicle in the test environment for more than a preset time length; controlling a transmission of the test vehicle to be in neutral, controlling an engine of the test vehicle to start cold starting, and recording a crankshaft speed pulse signal of the engine.

[0009] Optionally, the second test strategy comprises: performing a warm-up driving of the test vehicle, obtaining an engine water temperature and a driving mileage of the test vehicle; if it is identified that the engine water temperature reaches a preset temperature or the driving mileage reaches a preset mileage or above, it is determined that the test vehicle completes the warm-up driving; controlling the transmission of the test vehicle to be in neutral, controlling the engine of the test vehicle to work in an idle condition until the engine speed is maintained in a target speed range, and then recording a crankshaft speed pulse signal of the engine.

[0010] Optionally, before testing the engine according to the target test strategy, the method further comprises: controlling the geometric center of the front end face of the Hall sensor to be directly opposite the center line of the radial direction of the starting gear ring of the engine, and controlling the distance between the front end face of the Hall sensor and the gear ring tooth top to be within a target distance range.

[0011] Optionally, the reference angle value is determined according to the target test condition, comprising: obtaining a second corresponding relationship table of the target test condition and the reference angle value; and taking the target test condition as an index, querying the second corresponding relationship table to obtain the reference angle value.

[0012] Optionally, the reference angle value comprises a total value of the engine rotation angle fluctuation angle and at least one of the engine rotation angle fluctuation angle under a frequency corresponding to an ignition order, wherein if the target test condition is a cold engine starting condition, the reference angle value is the total value of the engine rotation angle fluctuation angle, and if the target test condition is a hot engine idle condition, the reference angle value comprises the total value of the engine rotation angle fluctuation angle and the engine rotation angle fluctuation angle under the frequency corresponding to the ignition order.

[0013] The second aspect embodiment of the application provides an engine body vibration evaluation device, comprising: an acquisition module configured to acquire a target test condition of an engine and determine a target test strategy according to the target test condition; a test module configured to test the engine according to the target test strategy, acquire a crankshaft speed pulse signal in an engine test process, and convert the crankshaft speed pulse signal into a transient angular velocity signal; and a determination module configured to filter a vibration signal from the transient angular velocity signal, obtain an engine rotation angle fluctuation angle signal by integrating the vibration signal, determine a reference angle value according to the target test condition, and determine an engine body vibration evaluation result according to an angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value.

[0014] Optionally, the acquisition module is further configured to acquire a first corresponding relationship table of the target test condition and the target test strategy; and take the target test condition as an index to query the first corresponding relationship table to obtain the target test strategy.

[0015] Optionally, the target test working condition includes a cold start working condition and a hot idle working condition, the target test strategy corresponding to the cold start working condition is a first test strategy, and the target test strategy corresponding to the hot idle working condition is a second test strategy.

[0016] Optionally, the acquisition module is further configured to place the test vehicle in a test environment of the target temperature range, keep the test vehicle in the test environment for a preset time period, control the transmission of the test vehicle to be in neutral, control the engine of the test vehicle to start cold starting, and record the crankshaft speed pulse signal of the engine.

[0017] Optionally, the second test strategy includes: performing warm-up driving on the test vehicle, acquiring the engine water temperature and the driving mileage of the test vehicle, determining that the test vehicle completes the warm-up driving if it is identified that the engine water temperature reaches a preset temperature or the driving mileage reaches a preset mileage or more, controlling the transmission of the test vehicle to be in neutral, controlling the engine of the test vehicle to work in an idle working condition until the speed of the engine is maintained in a target speed range, and recording the crankshaft speed pulse signal of the engine.

[0018] Optionally, the embodiment of the application further includes a control module configured to, before testing the engine according to the target test strategy, control the geometric center of the front end face of the Hall sensor to be directly opposite the center line of the starting gear ring of the engine in the radial direction, and control the distance between the front end face of the Hall sensor and the tooth top of the gear ring to be in a target distance range.

[0019] Optionally, the determination module is further configured to acquire a second corresponding relationship table of the target test working condition and the reference angle value, and query the second corresponding relationship table to obtain the reference angle value with the target test working condition as an index.

[0020] Optionally, the reference angle value includes a total value of the engine rotation angle fluctuation angle and at least one of the engine rotation angle fluctuation angle at a frequency corresponding to the ignition order, wherein if the target test working condition is the cold start working condition, the reference angle value is the total value of the engine rotation angle fluctuation angle, and if the target test working condition is the hot idle working condition, the reference angle value includes the total value of the engine rotation angle fluctuation angle and the engine rotation angle fluctuation angle at the frequency corresponding to the ignition order.

[0021] The third aspect embodiment of the application provides a vehicle, and the engine of the vehicle is evaluated by using the engine body vibration evaluation method.

[0022] Therefore, the application has the following beneficial effects: The embodiment of the application obtains the target test working condition of the cold start working condition and the hot idle working condition of the engine, that is, the corresponding reference angle value, determines the corresponding target test strategy according to different target test working conditions and performs test, obtains the crankshaft speed pulse signal of the engine in the test process, and then converts it into a transient angular velocity signal, filters the vibration signal from the transient angular velocity signal, and then integrates to obtain the rotation angle fluctuation angle signal of the engine, determines the body vibration evaluation result of the engine according to the angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value, and realizes the objective quantitative evaluation of the engine body vibration through the test strategy adapted to the working condition and the accurate signal processing, realizes the objective quantitative evaluation of the vibration, and improves the evaluation efficiency and accuracy. Therefore, the problems of low evaluation efficiency and poor accuracy in the related art are solved by the bench test method for evaluating the engine body vibration.

[0023] The additional aspects and advantages of the application will be partially given in the following description, partially become obvious from the following description, or be known by the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The above and / or additional aspects and advantages of the application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which: Figure 1 A flowchart of an engine body vibration evaluation method according to an embodiment of the application is provided. Figure 2 A flowchart of an engine body vibration evaluation method according to an embodiment of the application is provided. Figure 3 An example diagram of an engine body vibration evaluation device according to an embodiment of the application is provided. DETAILED DESCRIPTION

[0025] The embodiments of the application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, in which the same or similar notations represent the same or similar elements or elements having the same or similar functions. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application.

[0026] An engine body vibration evaluation method, device and vehicle according to an embodiment of the present application are described below with reference to the accompanying drawings. In view of the problems of low efficiency and poor accuracy in evaluating engine body vibration by the bench test method in the related art mentioned above, the present application provides an engine body vibration evaluation method. In the method, a target test condition of an engine is obtained, and a target test strategy is determined according to the target test condition. The engine is tested according to the target test strategy, a crankshaft speed pulse signal in the test process of the engine is obtained, and the crankshaft speed pulse signal is converted into a transient angular velocity signal. A vibration signal is filtered from the transient angular velocity signal, an angle fluctuation angle signal of the engine is obtained by integrating the vibration signal, a reference angle value is determined according to the target test condition, and a body vibration evaluation result of the engine is determined according to an angle value corresponding to the angle fluctuation angle signal and the reference angle value. Thus, the problems of low efficiency and poor accuracy in evaluating engine body vibration by the bench test method in the related art are solved.

[0027] Specifically, Figure 1 A flowchart of an engine body vibration evaluation method provided by an embodiment of the present application is shown in FIG. 1.

[0028] As Figure 1 shown, the engine body vibration evaluation method includes the following steps: In step S101, a target test condition of an engine is obtained, and a target test strategy is determined according to the target test condition.

[0029] The target test condition is a cold start condition and a hot idle condition in engine body vibration testing, and the target test strategy is a complete execution scheme formulated around the target test condition to achieve the test purpose.

[0030] It can be understood that the embodiment of the present application can determine the target test strategy by obtaining the target test condition of the engine, can lock the real use scenario of the user, ensures that the test does not deviate from the actual application scenario, designs special tests based on the working condition, and realizes that the test data directly reflects the problems in the user's use.

[0031] Specifically, the power, economy, NVH and reliability of the engine are related to specific working conditions. For example, a passenger car needs to cover the low speed / medium speed / high speed section of the cycle, and a commercial vehicle needs to focus on heavy load climbing and long downhill working conditions. Around the locked working condition, a test execution scheme is formulated, including sensor arrangement, data acquisition parameters, working condition operation sequence, variable control requirements, data analysis methods, etc. The measurement test is carried out on the whole vehicle, the vehicle state is normal, the measured vehicle and the test equipment are debugged, the test sample vehicle should ensure that the state is perfect, the performance under different working conditions meets the target requirements, the test equipment and sensors are calibrated to ensure that the test can efficiently and accurately obtain the required data and achieve the test purpose.

[0032] Further, in the embodiments of the present application, the target test strategy is determined according to the target test working condition, comprising: obtaining a first correspondence table of the target test working condition and the target test strategy; and querying the first correspondence table to obtain the target test strategy with the target test working condition as an index.

[0033] The first correspondence table is a table that one-to-one corresponds or maps the engine target test working condition and the target test strategy.

[0034] It can be understood that, by querying the first correspondence table to obtain the target test strategy with the target test working condition as an index in the first correspondence table of the target test working condition and the target test strategy, the target test strategy under the target test working condition can be quickly queried, the test data is ensured to be homologous and unified standard, and the test efficiency is greatly improved and the test cost is reduced.

[0035] Specifically, the engine test needs to cover multiple working conditions, and the experience and design ideas of different test personnel may differ. The first correspondence table fixes the target test working condition and the target test strategy. In the first correspondence table, the strategy corresponding to each working condition is verified by engineering, and the strategy can be directly ensured to be consistent with the working condition requirement by querying and calling, so that the target test working condition is consistent and the test strategy obtained by querying is completely unified.

[0036] Further, in the embodiments of the present application, the target test working condition comprises a cold start working condition and a hot idle working condition, the target test strategy corresponding to the cold start working condition is a first test strategy, and the target test strategy corresponding to the hot idle working condition is a second test strategy.

[0037] The cold start working condition is a process working condition in which the engine is in a cold state, each component of the engine is ensured to rotate from a static state through a starting system, and the engine is stably operated until the engine is stably operated. The hot idle working condition is a working condition in which the engine is stably operated at a normal working temperature without external output load and at a rated idle speed. The first test strategy is a test execution scheme designed for the transient characteristics and test targets of the cold start working condition. The second test strategy is a test execution scheme designed for the steady-state characteristics and test targets of the hot idle working condition.

[0038] It can be understood that, by setting the target test strategy corresponding to the target test working condition of the cold start working condition as the first test strategy and setting the target test strategy corresponding to the target test working condition of the hot idle working condition as the second test strategy, different test strategies can be used for the cold start working condition and the hot idle working condition, and the effectiveness and accuracy of the test data can be improved by using the corresponding test strategy to handle the faults corresponding to different working conditions.

[0039] Specifically, cold start and hot idle are two core working conditions in users' daily use of vehicles, which directly determine users' experience of engine starting convenience and idle smoothness. The working condition characteristics of cold start and hot idle are quite different, and the exposed problems are completely different. In the case of low temperature, transient state, large gap between components and high oil viscosity, problems such as starting failure, cold state abnormal noise, slow oil pressure establishment, unstable ignition / injection system are prone to occur. Therefore, the first test strategy captures transient faults through high-speed acquisition and full-process coverage, focuses on the transient process of cold start, and verifies the starting success rate and cold state smoothness. In the case of normal temperature, steady state, well-coordinated components and stable combustion, problems such as idle speed fluctuation, steady state abnormal noise, high idle fuel consumption and excessive emissions are prone to occur. Therefore, the second test strategy focuses on the steady state performance of hot idle and verifies the idle stability by long-term monitoring and high-precision control of steady state defects.

[0040] Further, in the embodiments of the present application, the first test strategy comprises: placing the test vehicle in a test environment with a target temperature range; placing the test vehicle in the test environment for more than a preset time; controlling the transmission of the test vehicle to be in neutral, and controlling the engine of the test vehicle to start cold, and recording the crankshaft speed pulse signal of the engine.

[0041] Wherein, the target temperature range is a controllable test environment air temperature interval set to simulate the real cold state of the engine; the test environment is a closed or semi-closed space that can accurately control temperature, humidity, air pressure and other environmental parameters; the transmission is a component of the vehicle powertrain used to change the speed and torque of the engine crankshaft and transmit it to the wheels; cold start is the process of starting the engine by the starter to rotate the crankshaft to ignite the combustible mixture, so that the engine transitions from a static state to a self-stable operation under the condition that the coolant temperature is below 25℃ and has been stopped for a long time; the crankshaft speed pulse is a periodic electrical pulse signal generated by a sensor when a signal disc installed on the engine crankshaft rotates.

[0042] It can be understood that the first test strategy is to place the test vehicle in a test environment with a target temperature for a preset time, start the engine cold after the transmission is in neutral, and record the crankshaft speed pulse signal. The first test strategy can ensure that the engine is in a standard cold state, focus on its cold start performance, eliminate interference, accurately capture the cold start state, and ensure the repeatability and comparability of the data.

[0043] Specifically, the target temperature range in the first test strategy is between 15℃ and 25℃, and the preset standing time in the first test strategy is 8 hours, that is, the vehicle needs to be placed in a test environment with a temperature of 15℃-25℃ for more than 8 hours before the test, simulating the real temperature working condition of cold start of the engine, excluding the interference of natural environmental temperature fluctuation such as diurnal temperature difference and regional climate difference on the test result, and the vehicle is fixed during the test, the transmission is in neutral, the engine is not started and no operation is performed, the temperature of the engine and key components needs to be consistent with the ambient temperature, such as the oil, coolant and cylinder temperature all reach the ambient temperature ±1℃, to ensure that the engine and transmission system are in a completely cold state, and during the starting process in the completely cold state, the real engine crankshaft speed signal during the entire cold start process is recorded.

[0044] Further, in the embodiment of the present application, the second test strategy includes: preheating the test vehicle to drive, obtaining the engine water temperature and the driving mileage of the test vehicle; if it is identified that the engine water temperature reaches a preset temperature, or the driving mileage reaches a preset mileage or more, it is determined that the test vehicle completes the preheating driving; the transmission of the test vehicle is controlled to be in neutral, and the engine of the test vehicle is controlled to work in an idle speed condition until the speed of the engine is maintained in a target speed range, and then the crankshaft speed pulse signal of the engine is recorded.

[0045] Among them, the preset temperature is a water temperature threshold for judging that the engine reaches a normal working hot state; the driving mileage is a preset minimum driving distance to ensure that the engine and the vehicle system are fully preheated; the preheating driving is an operation process of making the engine transition from cold / hot state to normal working hot state through actual road driving; the idle speed condition is a working state in which the engine has no external output power and the throttle is at the minimum opening, and maintains stable operation of itself.

[0046] It can be understood that the second test strategy is to preheat the test vehicle to drive, synchronously collect the engine water temperature and the driving mileage data, complete the preheating when any one of the conditions that the engine water temperature reaches the preset temperature or the driving mileage reaches the preset mileage is met, place the transmission in neutral after the preheating is completed, control the engine to enter the idle speed condition, record the engine crankshaft speed pulse signal after the speed is stabilized in the target speed range, the second test strategy can ensure that the engine is in a completely hot state, ensure that the fluctuation of the speed data only reflects the internal problem of the engine, simulate the real use scene, accurately locate the problem source, and ensure the practicality of the test data.

[0047] Specifically, the engine water temperature preset temperature in the second test strategy is (85±5) °C, and the preset mileage in the second test strategy is 15 km, that is, the second test strategy requires that the vehicle should be preheated to drive before the test, so that the engine water temperature reaches (85±5) °C or the driving distance is more than 15 km, to determine that the test vehicle completes the preheating driving, simulates the real hot state scene after the user's daily driving, and the vehicle is fixed during the test. The transmission is in neutral, the engine is started according to the normal operation, the oil pedal is not stepped, the ECU (Electronic Control Unit) is automatically adjusted to the idle speed condition, the engine is stably operated in the idle speed condition, the crankshaft speed is continuously monitored, until the speed fluctuation range is in the target range, and the crankshaft speed signal is recorded when the engine is in the idle speed condition.

[0048] The embodiment of the application can obtain the target test condition of the engine, query the first test strategy corresponding to the cold start condition and the second test strategy corresponding to the hot idle condition in the first corresponding relationship table of the target test condition and the target test strategy, lock the real use scene of the user, ensure that the test does not deviate from the actual application scene, design special tests based on the condition, and realize that the test data directly reflects the problems in the user's use.

[0049] In step S102, the engine is tested according to the target test strategy, the crankshaft speed pulse signal in the engine test process is obtained, and the crankshaft speed pulse signal is converted into a transient angular velocity signal.

[0050] The transient angular velocity signal is the instantaneous rotational angular velocity data of the rotating component in a very short time.

[0051] It can be understood that the embodiment of the application can obtain the crankshaft speed pulse signal in the engine test process by testing the engine according to the target test strategy, and then convert the obtained crankshaft speed pulse signal into a transient angular velocity signal. The discrete original speed pulse signal is converted into engine microcosmic dynamic operation data that can be quantified and interpreted, so as to facilitate the evaluation of the engine vibration level and guide the subsequent engine NVH optimization.

[0052] Specifically, the engine is tested according to the target test strategy, the number of teeth of the engine starting gear ring is not less than 60, the distance between the front end surface of the engine sensor and the tooth top of the gear ring is 0.5 mm to 3 mm, the crankshaft position sensor will constantly generate pulse signals with the rotation of the crankshaft, the data acquisition device observes the pulse signals at a very high frequency, and records the accurate time points of each pulse rising edge or falling edge, and the obtained original crankshaft speed pulse signal data is a series of time stamps, for example, [t1, t2, t3, t4,..., tn], wherein t1 is the time of the first pulse, t2 is the time of the second pulse, and so on.

[0053] The conversion of the crankshaft speed pulse signal into a transient angular velocity signal requires the calculation of the time difference between two adjacent pulses, for example, the time difference Δt1 = t2 - t1 between the first and second pulses, the time difference Δt2 = t3 - t2 between the second and third pulses, and so on, to obtain the time interval [Δt1, Δt2, Δt3,...]. Assuming that the signal disc has N teeth, the crankshaft will generate N pulses per revolution, and the angle corresponding to one tooth is 360° / N. In the time Δt, the crankshaft rotates an angle of 360° / N, and thus the instantaneous angular velocity is calculated from this angle and the time interval.

[0054] Further, in the embodiment of the present application, before testing the engine according to the target test strategy, the geometric center of the front end face of the Hall sensor is aligned with the radial center line of the starting gear ring of the engine, and the distance between the front end face of the Hall sensor and the tooth top of the gear ring is controlled to be within a target distance range.

[0055] The Hall sensor is a non-contact electromagnetic induction sensor for converting the mechanical rotary motion of the crankshaft into an electrical signal; the starting gear ring is a ring-shaped mechanical component fixed at the front end or rear end of the engine crankshaft and cooperating with the Hall sensor to collect the speed / position signal; and the target distance range is the gap distance threshold between the front end face of the Hall sensor and the tooth top of the starting gear ring.

[0056] It can be understood that, before testing the engine according to the target test strategy, the geometric center of the front end face of the Hall sensor needs to be aligned with the radial center line of the starting gear ring of the engine, and the distance between the front end face of the Hall sensor and the tooth top of the gear ring needs to be controlled to be within a target distance range. By aligning the geometric center of the front end face of the Hall sensor with the radial center line of the starting gear ring of the engine, it can be ensured that the entire gear ring tooth width uniformly covers the Hall element of the sensor front end, the magnetic field change presents a symmetrical rising and symmetrical falling rule, a symmetrical pulse signal waveform is achieved, and the accuracy of the pulse time interval calculation is ensured.

[0057] Specifically, the Hall sensor is used to complete the speed pulse signal measurement, the measurement range of which can be 0 r / min ~ 10000 r / min, the clock frequency of the speed module of the data acquisition system for testing can be 50 MHz, the maximum input pulse number can be not less than 350000 per second, and the geometric center of the front end face of the Hall sensor for measuring the engine speed pulse signal needs to be aligned with the radial center line of the starting gear ring of the engine.

[0058] The engine is tested according to the target test strategy, the crankshaft speed pulse signal in the engine test process is acquired, the acquired crankshaft speed pulse signal is converted into a transient angular velocity signal, the discrete original speed pulse signal is converted into engine micro-dynamic operation data which can be quantified and interpreted, and the engine vibration level is evaluated conveniently and quickly, thereby guiding subsequent engine NVH optimization.

[0059] In step S103, a vibration signal is filtered from the transient angular velocity signal, an angle fluctuation angle signal of the engine is obtained by integrating the vibration signal, a reference angle value is determined according to the target test condition, and the body vibration evaluation result of the engine is determined according to the angle value corresponding to the angle fluctuation angle signal and the reference angle value.

[0060] The vibration signal is a periodic / abnormal fluctuation component signal related to the engine body vibration extracted from the engine crankshaft transient angular velocity signal after filtering and processing to remove normal uniform speed / steady speed change; the angle fluctuation angle signal is a deviation amount signal of the actual crankshaft rotation angle and the ideal uniform rotation angle obtained by integrating the vibration signal; the reference angle value is the crankshaft ideal rotation angle reference value in the vibration-free / vibration-qualified state set according to the target test condition; and the body vibration evaluation result is a quantitative conclusion about the engine body vibration performance obtained by comparing the actual value of the angle fluctuation angle signal with the reference angle value.

[0061] It can be understood that the vibration signal is filtered from the transient angular velocity signal, the angle fluctuation angle signal of the engine is obtained by integrating the vibration signal, the body vibration evaluation result of the engine is determined according to the angle value corresponding to the angle fluctuation angle signal and the reference angle value of the target test condition, the strength of the torsional vibration is directly quantified through the angle fluctuation angle value, data support is provided for vibration optimization and fault positioning, and objective and quantitative evaluation of vibration is realized.

[0062] Specifically, the vibration signal is filtered from the transient angular velocity signal to remove non-vibration-related components such as uniform speed trend and high-frequency electromagnetic interference in the transient angular velocity signal, and to retain the fluctuation components related to the engine body vibration, the vibration signal is confirmed to be continuous without breakpoints, the vibration signal is time-integrated using data acquisition software, the change of angular velocity fluctuation amount with time is accumulated, time nodes are labeled synchronously during the integration process, and the time-domain original waveform of the angle fluctuation angle signal of the time and rotation angle deviation is obtained after integration. The reference angle value is determined according to the target test condition, and the engine rotation angle fluctuation angle measurement result is evaluated according to the engine rotation angle fluctuation angle standard under different conditions.

[0063] Further, in the embodiments of the present application, the reference angle value is determined according to the target test working condition, comprising: obtaining a second correspondence table of the target test working condition and the reference angle value; and querying the second correspondence table to obtain the reference angle value with the target test working condition as the index.

[0064] The second correspondence table is a structured mapping data table with the target test working condition as the retrieval core and the reference angle value as the output result.

[0065] It can be understood that the second correspondence table of the one-to-one mapping of the target test working condition and the reference angle value is obtained first, and then the matching item is queried in the table with the current target test working condition as the retrieval condition to directly obtain the corresponding reference angle value, which can unify the evaluation benchmark, simplify the operation process, ensure the evaluation consistency, improve the test efficiency, support the standardization of the test process, and guarantee the reproducibility and objective credibility of the evaluation result.

[0066] Specifically, as shown in Table 1, the engine angle fluctuation angle result is sorted, evaluated based on the fluctuation angle evaluation standard under different working conditions, and the engine angle fluctuation angle measurement result item is evaluated. The fluctuation angle final result is required to be less than or equal to the limit value, and the result is qualified, and the limit value is unqualified.

[0067] Table 1 Engine angle fluctuation angle evaluation standard

[0068] Further, in the embodiments of the present application, the reference angle value includes a total value of the engine angle fluctuation angle and at least one of the engine angle fluctuation angle under the frequency corresponding to the ignition order, wherein if the target test working condition is a cold start working condition, the reference angle value is the total value of the engine angle fluctuation angle, and if the target test working condition is a hot idle working condition, the reference angle value includes the total value of the engine angle fluctuation angle and the engine angle fluctuation angle under the frequency corresponding to the ignition order.

[0069] The angle fluctuation angle is the deviation between the instantaneous angle and the angle when the engine crankshaft is ideally rotated at a constant speed during actual rotation; the ignition order is the frequency order corresponding to the number of times of spark plug ignition in one revolution of the engine; and the hot idle working condition is an operating state in which the engine reaches a normal operating temperature, has no external load, and the speed is stable in the idle speed interval.

[0070] It can be understood that the reference angle value is selectively determined according to different target test working conditions, the total value of the engine rotation angle fluctuation angle is taken under the cold start working condition, and the total value and the engine rotation angle fluctuation angle under the frequency corresponding to the ignition order are taken under the hot idle working condition. The reference angle value at least contains one of the two, which can adapt to the characteristic difference of different working conditions, accurately obtain the key data of the engine rotation angle fluctuation, provide a basis for engine NVH performance test, fault diagnosis and operation stability optimization, and improve the reliability and reference of the test results.

[0071] Specifically, for the cold start working condition, when the cold start, the engine temperature is low, the lubricating oil viscosity is large, and the gap between each part may be in an unfavorable state due to low temperature, and the fuel atomization and combustion efficiency are also relatively low. The system integrates the collected speed transient angular velocity signal in time to obtain a rotation angle fluctuation angle signal of the crankshaft relative to its average speed, and outputs the total value of the engine rotation angle fluctuation angle, which can macroscopically reflect the severity of the engine speed fluctuation during the cold start process.

[0072] For the hot idle working condition, when the engine reaches the normal working temperature, the parameters of the engine are relatively stable, and the combustion efficiency is high. However, under the idle working condition, the engine load is small, the speed is low, and the combustion fluctuation and mechanical disturbance are very sensitive. Similar to the cold start working condition, the speed transient angular velocity signal is integrated to obtain a rotation angle fluctuation angle signal, and the total value of the engine rotation angle fluctuation angle and the engine rotation angle fluctuation angle under the frequency corresponding to the ignition order are output.

[0073] The application embodiment filters the vibration signal from the transient angular velocity signal, integrates the vibration signal to obtain the rotation angle fluctuation angle signal of the engine, determines the body vibration evaluation result of the engine according to the angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value of the target test working condition, directly quantifies the strength of the torsional vibration through the rotation angle fluctuation angle value, provides data support for vibration optimization and fault positioning, realizes objective and quantitative evaluation of the vibration, and improves the efficiency and accuracy of evaluating the contribution of engine combustion to the body vibration amplitude.

[0074] In order to better understand the scheme of the present application, the engine body vibration evaluation method or execution process of the present application is described below through a specific embodiment, as shown in Figure 2 In step S201, the test vehicle is prepared and the state is confirmed.

[0075] The measurement test is carried out on the whole vehicle, the vehicle state is normal, and the evaluation requirements are met.

[0076] In step S202, the test is prepared.

[0077] ​Debugging the vehicle and test equipment, the test vehicle should ensure the state of good, different conditions performance meet the target requirements; test equipment and sensor calibration is completed.

[0078] In step S203, the engine speed pulse measurement of the whole vehicle state is performed.

[0079] The speed pulse signal measurement is completed using a Hall sensor, and the measurement range can be 0 r / min-10000 r / min.

[0080] The speed module clock frequency of the data acquisition system for testing is 50 MHz, and the maximum input pulse number is not less than 350000 per second.

[0081] The geometric center of the front end of the Hall sensor for measuring the engine speed pulse signal is directly opposite the center line of the engine starting gear ring in the radial direction, and the distance between the sensor front end and the gear ring tooth top is 0.5 mm-3 mm. Ensure that the correct pulse signal is collected, and the number of engine starting gear teeth is not less than 60.

[0082] Confirm the test condition, the engine is in the whole vehicle working state, measure the speed fluctuation under the cold start and hot idle condition.

[0083] Cold start condition measurement, before the test, the vehicle should be placed in the test environment with temperature of 15 ℃-25 ℃ for more than 8 hours. During the test, the vehicle is fixed, the transmission is in neutral, and the engine crankshaft speed signal during the whole cold start process is recorded.

[0084] Hot engine idle condition measurement, before the test, the vehicle should be preheated for driving, so that the engine water temperature reaches (85±5) ℃ or drives for more than 15 km. During the test, the vehicle is fixed, the transmission is in neutral, the engine is in idle condition, and the engine idle condition crankshaft speed signal is recorded.

[0085] The selected vehicle is tested under the selected condition.

[0086] The objective test process includes objective test, data processing and objective test result evaluation.

[0087] Objective testing refers to measuring the engine crankshaft speed pulse signal and processing and analyzing the objective test results. During the test, the engine oil temperature, engine cooling medium temperature, test room environment temperature and other signals are recorded synchronously.

[0088] In step S204, the pulse signal is converted into transient angular velocity signal.

[0089] Select the effective test signal test group, that is, the engine speed time domain data is stable, without obvious mutation fluctuation or abnormal test group, and calculate the speed fluctuation angle by using time-frequency analysis.

[0090] In step S205, filtering processing, resampling processing.

[0091] Convert the rotational speed pulse signal into a time-domain raw waveform of the transient angular velocity signal.

[0092] Filter the transient angular velocity signal using a band-pass filter to filter out a 5-100 Hz vibration signal.

[0093] Resample the transient rotational speed signal using the sampling frequency of other input channels (such as sound pressure, vibration).

[0094] In step S206, output the rotational speed fluctuation self-power spectrum and order spectrum.

[0095] Calculate the self-power spectrum and order spectrum of the transient angular velocity.

[0096] In step S207, rotational speed fluctuation angle objective test evaluation. For the cold start condition, integrate the rotational speed transient angular velocity signal to obtain the angle signal of the rotational angle fluctuation, and output the total value of the engine rotational angle fluctuation angle.

[0097] For the hot idle condition, integrate the rotational speed transient angular velocity signal to obtain the angle signal of the rotational angle fluctuation, and output the total value of the engine rotational angle fluctuation angle and the engine rotational angle fluctuation angle at the frequency corresponding to the ignition order.

[0098] In step S208, score the results.

[0099] Evaluate the engine rotational angle fluctuation angle measurement results according to the engine rotational angle fluctuation angle standard under different conditions.

[0100] In step S209, evaluate the degree of influence of combustion excitation on engine body vibration. Evaluate the engine rotational angle fluctuation angle measurement results based on the fluctuation angle evaluation standard under different conditions.

[0101] Organize the engine rotational angle fluctuation angle results and evaluate them according to the evaluation standard of different conditions. If the final result of the fluctuation angle is less than or equal to the limit value, the result is qualified, and if it exceeds the limit value, it is unqualified.

[0102] In summary, the engine vibration evaluation method proposed in this application obtains the target test conditions, namely the cold start condition and the hot idle condition of the engine, and the corresponding reference angle values. Based on different target test conditions, a corresponding target test strategy is determined and tested. During the test, the crankshaft speed pulse signal of the engine is acquired and converted into a transient angular velocity signal. The vibration signal is filtered out from the transient angular velocity signal and then integrated to obtain the engine's angular fluctuation angle signal. Based on the angle value corresponding to the angular fluctuation angle signal and the reference angle value, the engine vibration evaluation result is determined. Through a test strategy adapted to the operating conditions and precise signal processing, an objective quantitative evaluation of engine vibration is achieved, improving the efficiency and accuracy of assessing the contribution of engine combustion to the vibration amplitude.

[0103] Next, the engine body vibration evaluation device proposed according to the embodiments of this application is described with reference to the accompanying drawings.

[0104] Figure 3 This is a block diagram of the engine body vibration evaluation device according to an embodiment of this application.

[0105] like Figure 3 As shown, the engine body vibration evaluation device 300 includes: an acquisition module 301, a testing module 302, and a determination module 303.

[0106] The acquisition module 301 is used to acquire the target test conditions of the engine and determine the target test strategy based on the target test conditions; the test module 302 is used to test the engine according to the target test strategy, acquire the crankshaft speed pulse signal during the engine test process, and convert the crankshaft speed pulse signal into a transient angular velocity signal; the determination module 303 is used to filter out the vibration signal from the transient angular velocity signal, obtain the engine's angular fluctuation angle signal based on the integration of the vibration signal, determine the reference angle value based on the target test conditions, and determine the engine's body vibration evaluation result based on the angle value corresponding to the angular fluctuation angle signal and the reference angle value.

[0107] Furthermore, in the embodiments of this application, the acquisition module 301 is further used to acquire a first correspondence table between the target test conditions and the target test strategy; and to query the first correspondence table using the target test conditions as an index to obtain the target test strategy.

[0108] Furthermore, in the embodiments of this application, the target test conditions include cold start condition and hot idle condition. The target test strategy corresponding to the cold start condition is the first test strategy, and the target test strategy corresponding to the hot idle condition is the second test strategy.

[0109] Further, in the embodiment of the present application, the acquisition module 301 is further configured to place the test vehicle in a test environment of a target temperature range; place the test vehicle in the test environment for a preset time duration; control the transmission of the test vehicle to be in neutral gear; control the engine of the test vehicle to start cold start; and record the crankshaft speed pulse signal of the engine.

[0110] Further, in the embodiment of the present application, the second test strategy comprises: performing warm-up driving of the test vehicle, acquiring the engine water temperature and the driving mileage of the test vehicle; if it is identified that the engine water temperature reaches a preset temperature or the driving mileage reaches a preset mileage or above, it is determined that the test vehicle completes the warm-up driving; controlling the transmission of the test vehicle to be in neutral gear; controlling the engine of the test vehicle to work in an idle speed operating condition until the speed of the engine is maintained in a target speed range, and then recording the crankshaft speed pulse signal of the engine.

[0111] Further, in the embodiment of the present application, the engine body vibration evaluation device 300 of the embodiment of the present application further comprises: a control module.

[0112] The control module is configured to, before testing the engine according to the target test strategy, control the distance between the front end surface of the Hall sensor and the tooth top of the gear ring to be within a target distance range, with the geometric center of the front end surface of the Hall sensor being directly opposite the center line of the starting gear ring of the engine in the radial direction.

[0113] Further, in the embodiment of the present application, the determination module 303 is further configured to acquire a second correspondence table of the target test operating condition and the reference angle value; and query the second correspondence table to obtain the reference angle value with the target test operating condition as an index.

[0114] Further, in the embodiment of the present application, the reference angle value comprises a total value of the engine rotation angle fluctuation angle and at least one of the engine rotation angle fluctuation angle at a frequency corresponding to the ignition order, wherein, if the target test operating condition is a cold engine starting operating condition, the reference angle value is the total value of the engine rotation angle fluctuation angle, and if the target test operating condition is a hot engine idle speed operating condition, the reference angle value comprises the total value of the engine rotation angle fluctuation angle and the engine rotation angle fluctuation angle at a frequency corresponding to the ignition order.

[0115] It should be noted that the foregoing explanation and description of the engine body vibration evaluation method embodiment are also applicable to the engine body vibration evaluation device of the embodiment, which will not be described here again.

[0116] In summary, according to the engine body vibration evaluation device provided in the embodiments of the present application, the target test conditions of the cold start condition and the hot idle condition of the engine are obtained, that is, the corresponding reference angle values, the corresponding target test strategy is determined according to different target test conditions and the test is performed, the crankshaft speed pulse signal of the engine is obtained in the test process, which is then converted into a transient angular velocity signal, the vibration signal is filtered from the transient angular velocity signal, and the rotation angle fluctuation angle signal of the engine is obtained by integration. According to the angle value corresponding to the rotation angle fluctuation angle signal and the reference angle value, the evaluation result of the engine body vibration is determined. Through the test strategy adapted to the working condition and the accurate signal processing, the objective and quantitative evaluation of the engine body vibration is realized, the objective and quantitative evaluation of the vibration is realized, and the efficiency and accuracy of evaluating the contribution of engine combustion to the amplitude of the body vibration are improved.

[0117] The embodiments of the present application also provide a vehicle, and the engine of the vehicle is evaluated by using the engine body vibration evaluation method.

[0118] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms is not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0119] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0120] Any process or method descriptions in flow charts or otherwise described herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) in the process, and the various embodiments of the present application include additional implementations in which the order of steps can differ from those shown or discussed, including a step can occur at substantially the same time with other steps or can be performed in reverse order, and additional steps can be included, all of which have been changed from the order described herein, which should be understood by those skilled in the art of the present application.

[0121] It should be understood that portions of the application can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. As such, if implemented in hardware, as in another embodiment, any of the following technology, known in the art, can be employed for implementing: a hybrid of the techniques described herein; discrete logic circuitry having logic gates for implementing logic functions upon data signals; application specific integrated circuits having appropriate combinational logic gates; programmable gate arrays; field programmable gate arrays, or the like.

[0122] Those skilled in the art can understand that all or part of the steps carried out by the method of the above-mentioned embodiments can be completed by a program instructing the relevant hardware, and the above-mentioned program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0123] Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. An engine body vibration evaluation method characterized by comprising: The method comprises the following steps: obtaining a target test condition of the engine, and determining a target test strategy according to the target test condition; testing the engine according to the target test strategy, obtaining a crankshaft speed pulse signal in the test process of the engine, and converting the crankshaft speed pulse signal into a transient angular velocity signal; filtering a vibration signal from the transient angular velocity signal, integrating the vibration signal to obtain a crank angle fluctuation angle signal of the engine, determining a reference angle value according to the target test condition, and determining a body vibration evaluation result of the engine according to an angle value corresponding to the crank angle fluctuation angle signal and the reference angle value.

2. The engine body vibration evaluation method according to claim 1, characterized by, The target test strategy is determined according to the target test condition, comprising: obtaining a first corresponding relationship table of the target test condition and the target test strategy; querying the first corresponding relationship table to obtain the target test strategy with the target test condition as an index.

3. The engine body vibration evaluation method according to claim 2, characterized by, The target test condition comprises a cold start condition and a hot idle condition, the target test strategy corresponding to the cold start condition is a first test strategy, and the target test strategy corresponding to the hot idle condition is a second test strategy.

4. The engine body vibration evaluation method according to claim 3, characterized by The first test strategy comprises: placing the test vehicle in a test environment with a target temperature range; placing the test vehicle in the test environment for more than a preset time length; controlling a transmission of the test vehicle to be in neutral, controlling an engine of the test vehicle to start cold starting, and recording a crankshaft speed pulse signal of the engine.

5. The engine body vibration evaluation method according to claim 3, characterized by The second test strategy comprises: preheating the test vehicle to obtain an engine water temperature and a driving mileage of the test vehicle; if it is identified that the engine water temperature reaches a preset temperature or the driving mileage reaches more than a preset mileage, it is determined that the test vehicle completes the preheating driving; controlling the transmission of the test vehicle to be in neutral, controlling the engine of the test vehicle to work in an idle condition, and recording the crankshaft speed pulse signal of the engine until the speed of the engine is maintained in a target speed range.

6. The engine body vibration evaluation method according to claim 1, characterized by Before testing the engine according to the target test strategy, the method further comprises: controlling a geometric center of a front end surface of a Hall sensor to be directly opposite a center line of a starting gear ring of the engine in a radial direction, and controlling a distance between the front end surface of the Hall sensor and a gear top of the starting gear ring to be in a target distance range.

7. The engine body vibration evaluation method according to claim 1, characterized by The reference angle value is determined according to the target test condition, comprising: obtaining a second corresponding relationship table of the target test condition and the reference angle value; querying the second corresponding relationship table to obtain the reference angle value with the target test condition as an index.

8. The engine body vibration evaluation method according to claim 1, characterized by The reference angle value comprises a total value of engine crank angle fluctuation angles and at least one engine crank angle fluctuation angle corresponding to a frequency of a firing order, wherein if the target test condition is the cold start condition, the reference angle value is the total value of the engine crank angle fluctuation angles, and if the target test condition is the hot idle condition, the reference angle value comprises the total value of the engine crank angle fluctuation angles and the engine crank angle fluctuation angle corresponding to the frequency of the firing order.

9. An engine body vibration evaluation device characterized by comprising: The method comprises: an obtaining module, configured to obtain a target test condition of an engine, and determine a target test strategy according to the target test condition; a testing module, configured to test the engine according to the target test strategy, obtain a crankshaft speed pulse signal in the test process of the engine, and convert the crankshaft speed pulse signal into a transient angular velocity signal; The determining module is configured to filter a vibration signal from the transient angular velocity signal, to obtain a fluctuation angle signal of the engine according to integration of the vibration signal, to determine a reference angle value according to a target test working condition, and to determine the body vibration evaluation result of the engine according to a corresponding angle value of the fluctuation angle signal and the reference angle value.

10. A vehicle characterized by comprising: The engine of the vehicle is evaluated by using the engine body vibration evaluation method according to any one of claims 1-8.

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