Automobile air conditioner compressor NVH performance dynamic calibration method and system

Abstract

This invention discloses a dynamic calibration method for the NVH performance of an automotive air conditioning compressor, comprising the following steps: S1, compressor selection and bracket design; S2, setting compressor NVH analysis targets; S4, NVH test simulation benchmarking of the compressor bracket assembly; S5, compressor unit NVH noise test control; S6, setting compressor-wide vehicle noise and vibration targets; S7, compressor-wide vehicle noise and vibration test; S8, compressor-wide vehicle noise and vibration frequency avoidance design; S9, compressor start-stop calibration; S10, optimization of vehicle calibration strategy for environmental chamber simulation test; S11, locking of vehicle calibration strategy for environmental chamber simulation test; S12, determination of compressor verification conditions for high-altitude, high-temperature, and high-humidity tests; S13, optimization of dynamic NVH calibration of compressor for high-altitude, high-humidity, and high-humidity tests; S14, acceptance of dynamic NVH calibration strategy for compressor for high-altitude, high-humidity, and high-humidity tests. The present invention provides a dynamic calibration method for the NVH performance of automotive air conditioning compressors. By combining high-altitude, high-temperature, and high-humidity test data, and by optimizing and adjusting the compressor operating speed at specific speeds and adjusting the compressor transition speed state time control, the method improves the NVH performance of the vehicle air conditioning system without increasing hardware or costs. This achieves a globally optimal balance between air conditioning performance and ride comfort, meeting the development requirements for NVH ride comfort.

Description

Technical Field

[0001] This invention belongs to the field of NVH performance optimization technology for automotive air conditioning systems. Specifically, this invention relates to a method and system for dynamic calibration of NVH performance of automotive air conditioning compressors. Background Technology

[0002] Driven by both technological innovation and rising consumer spending, consumers are demanding higher quality driving experiences. The start-up, shutdown, and operation of the compressor are causing increasing NVH (noise, vibration, and harshness) issues, leading to numerous user complaints. Automotive compressors typically operate in relatively quiet environments (such as idling or low-speed driving). During compressor startup, the sudden change in electromagnetic torque from a standstill to high speed causes mechanical shock, resulting in body and steering wheel vibrations and high-frequency noise. Similarly, the sudden release of inertial load during compressor shutdown can trigger resonance in piping or supports, producing a low-frequency humming sound. Compressor start-up and shutdown calibration is crucial for NVH optimization, especially since significant noise, vibration, and roughness can easily occur during compressor startup and shutdown. Under different operating conditions (such as high-temperature, high-load startup versus low-temperature, cold startup), compressor loads vary greatly, requiring dynamic parameter calibration to prevent NVH deterioration.

[0003] Traditional air conditioning compressor speed settings do not mitigate the impact of overall vehicle NVH characteristics. Air conditioning systems typically operate at compressor speeds between 1000-8800 rpm, with a frequency range of 16.6-146.6 Hz. The compressor's speed fluctuations from startup to final temperature equilibrium cannot completely avoid the vehicle's modal characteristics, leading to resonance with the body's components and causing NVH issues. Furthermore, during operation, once the blower speed is set, the VCU (Vehicle Control Unit) continuously adjusts the compressor's target speed based on occupant temperature requests, cabin temperature, and evaporator temperature. Repeatedly crossing resonant frequency bands or frequent start-stop cycles cause changes in the actual compressor speed, further deteriorating the vehicle's NVH performance. The compressor uses a passive vibration isolation bracket, which does not solve the problem of the source excitation. It reduces noise by fixing the PWM frequency, but does not cover the frequency adaptability under dynamic driving conditions (such as rapid acceleration / high altitude), resulting in residual high-frequency noise. The compressor speed is adjusted based on the ambient temperature, but does not cover altitude and humidity parameters. Poor heat dissipation under low air pressure at high altitudes causes the compressor to start and stop frequently, and there is still an imbalance between cooling efficiency and noise.

[0004] Traditional compressor control relies on a static speed-load map, which cannot dynamically adapt to extreme environments such as abnormal refrigerant circulation caused by low air pressure at high altitudes. Furthermore, it faces conflicts between the high-speed cooling demands of driving and idling conditions and high-frequency noise (NVH). It cannot cope with the various challenges posed by high-altitude, high-temperature, and high-humidity (HAH) testing. Commonly, high-temperature (50℃) compressor overload causes high-frequency whistling (>4kHz), resulting in in-vehicle noise exceeding the standard by >50dB(A); in extremely cold conditions (-30℃), insufficient lubrication during cold starts causes compressor vibration to be transmitted to the steering wheel (acceleration >0.4m / s²). 2 The problems of sudden increase in refrigerant cavitation noise (hissing sound) under low air pressure at high altitudes cannot be effectively solved or avoided.

[0005] This paper provides a method for dynamic calibration of the NVH performance of automotive air conditioning compressors, specifically on how to improve the NVH performance of real vehicle air conditioning by adjusting the compressor speed strategy without increasing hardware and costs, thereby achieving a globally optimal balance between air conditioning performance and ride comfort and meeting the development requirements for NVH ride comfort. Summary of the Invention

[0006] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for dynamically calibrating the NVH performance of an automotive air conditioning compressor. The purpose is to improve the NVH performance of a real-vehicle air conditioning system by adjusting the compressor speed strategy without increasing hardware or costs, achieving a globally optimal balance between air conditioning performance and ride comfort, and meeting the development requirements for NVH ride comfort.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for dynamic calibration of NVH performance of automotive air conditioning compressors, comprising the following steps:

[0008] S1. Compressor selection and bracket design: lightweight structural design based on performance requirements and installation space limitations;

[0009] S2. NVH analysis target setting for compressor: determine the target frequency range of the compressor bracket assembly modal, and avoid the frequency of external excitation sources and the compressor's own operating frequency.

[0010] S3. NVH analysis of the compressor bracket assembly: establish a finite element model for modal analysis, and verify the modal natural frequencies and dynamic stiffness of the mounting points;

[0011] S4. NVH test simulation benchmarking of compressor bracket assembly, and correction of simulation model through actual measurement data;

[0012] S5. NVH noise test control of individual compressors: Based on the compressor displacement selection range and maximum speed, set noise test parameters, including microphone installation position, exhaust pressure, intake pressure and speed, and control the frame noise within the target range.

[0013] S6. Set the vehicle noise and vibration target for the compressor, and combine the compressor frequency sweep test and subjective evaluation results to formulate the dynamic step target for the noise in the driver's right ear in the front row of the vehicle and the dynamic vibration target for the steering wheel in the vehicle.

[0014] S7. Compressor vehicle noise and vibration test: Based on the set target, the control level of the HVAC system blower is determined in conjunction with the blower. Under different blower levels, the compressor speed is controlled to complete the steady speed test and obtain the sound pressure level of the driver's right ear and the steering wheel vibration curve.

[0015] S8. Compressor vehicle noise and vibration avoidance frequency design, and formulate resonance frequency avoidance strategy; based on the vibration and noise target of the sweep frequency test and the obtained in-vehicle sound pressure level and vibration acceleration curve, formulate the resonance frequency that the air conditioning compressor needs to avoid in the speed increase range, and lock the idle speed condition avoidance design and the maximum compressor speed limit as the basic input for software calibration.

[0016] S9. Compressor start-stop calibration adopts a soft start / soft stop control strategy, which controls the compressor speed through a motor frequency conversion control drive strategy and dynamically adjusts the start-stop timing in combination with the overall vehicle status.

[0017] S10. Optimize the vehicle calibration strategy for environmental chamber simulation test, and dynamically adjust the compressor calibration strategy under simulated working conditions;

[0018] S11. The vehicle calibration strategy is locked in the environmental chamber simulation test. Based on the dynamically fine-tuned compressor calibration strategy, the vibration and noise test results of the vehicle air conditioning system compressor and the subjective evaluation results are carried out to determine the initial compressor calibration strategy.

[0019] S12, the operating conditions of the high-temperature, high-altitude, and high-cold-weather test compressor were determined, and road tests were conducted in high-temperature, high-altitude, and high-temperature environments;

[0020] S13. Dynamic NVH calibration optimization of the high-altitude, high-temperature, high-humidity test compressor: Based on the dynamic calibration, adaptive strategies for high-altitude, high-humidity, high-temperature environments are formulated. The compressor parameters are dynamically adjusted according to vehicle speed and load. The cooling capacity, energy consumption, vibration, and noise are calibrated simultaneously to determine the dynamic NVH calibration strategy for the high-altitude, high-humidity, high-temperature test compressor.

[0021] S14. Acceptance of dynamic NVH calibration strategy for high-temperature, high-humidity, and high-temperature test compressors shall be conducted in accordance with the preset acceptance standards.

[0022] In step S1, the performance indicators include cooling capacity, power consumption, and speed range; the installation space limitations include the length, width, and height dimensions of the engine compartment and the interface location; the lightweight structural design uses aluminum alloy materials.

[0023] The NVH analysis objectives include:

[0024] External excitation sources include engine idle speed 25Hz±15% and high speed 200Hz±15%;

[0025] The compressor's own operating frequency is 16.7-146.6Hz±15% corresponding to 1000-8800rpm;

[0026] Modal target frequency ≥230Hz.

[0027] The NVH analysis of the compressor bracket assembly includes:

[0028] Establish a finite element model that includes the shell, support, and moving parts;

[0029] Verify the natural frequencies of the first 10 modes;

[0030] The installation point dynamic stiffness requirement is an average value of >1500N / mm for 20-500Hz.

[0031] In step S5, the compressor displacement selection range is ≥27cm. 3 / r, the maximum permissible speed Rmax is 8800rpm; the microphone is installed 15cm directly above the center of the compressor; the exhaust pressure is set to 1.50±0.02MPa(abs), and the intake pressure is set to 0.3±0.005MPa(abs); the speed is set to 3000 / 4000 / 5000rpm, and the bench noise target is ≤75 / 85 / 90dB(A) respectively.

[0032] In step S6, the target dynamic noise levels for the driver's right ear in the front seat are: 1000-3000 rpm @ 42 dB(A), 3000-5000 rpm @ 43 dB(A), 5000-6000 rpm @ 45 dB(A), 6000-7000 rpm @ 47 dB(A), and 7000-8000 rpm @ 50 dB(A); the target dynamic vibration levels for the steering wheel are: 1000-3000 rpm @ 0.2 m / s 2 3000-5000rpm@0.4m / s 2 5000-7000rpm@0.4m / s 2 7000-8800rpm@0.5m / s 2 .

[0033] In step S7, the compressor speed is tested from the lowest Rmin to the highest Rmax stable operating speed in increments of 100 rpm; the steering wheel vibration curve is the steering wheel 12 o'clock direction vibration curve SPL.

[0034] In step S8, the idling condition is designed to avoid frequencies at 3200-3400rpm, and the maximum speed of the compressor is set to 8300rpm.

[0035] In step S9, the soft start is a ramp-like acceleration, and the soft stop is a gradual unloading of the electromagnetic force; the vehicle status includes engine speed and vehicle speed; the compressor starts delayed when the vehicle accelerates.

[0036] In step S12, the driving scenarios include idling, high speed, and rapid acceleration; the vehicle is a pickup truck, and the added specific environmental tests are a high-temperature durability test of continuous operation at 50°C for 8 hours in a desert environment, and a low-temperature cold start verification of the compressor lubrication performance at -30°C.

[0037] In step S13, the adaptive strategy for high-altitude, high-temperature, and high-temperature environments includes: at high vehicle speeds, prioritizing air cooling to reduce compressor load; when the vehicle speed is set to >80km / h, activating the five-dimensional map table: limiting the compressor speed to no more than 6000rpm / s; in high-temperature environments, suppressing high-frequency noise by increasing the PWM frequency to 18kHz; in cold-weather environments, activating the five-dimensional map table, reducing the compressor speed for soft-start adaptive adjustment, setting the initial speed to 800RPM and the displacement to 10%, and preheating for 3 minutes; in high-altitude environments, activating the five-dimensional map table, reducing the compressor speed by 12%, and increasing the refrigerant flow by 20%.

[0038] This invention also provides a dynamic calibration system for the NVH performance of an automotive air conditioning compressor, comprising:

[0039] The processor module is used to execute the calibration method described above;

[0040] The memory module stores the finite element model, experimental data, and calibration strategy parameters.

[0041] The control module enables soft start / soft stop control, dynamic speed adjustment, and five-dimensional Map architecture application.

[0042] The data acquisition module obtains bench noise data, actual vehicle vibration data, and environmental chamber test data.

[0043] The method for dynamic calibration of NVH performance of automotive air conditioning compressors of the present invention has the following beneficial effects:

[0044] 1. By controlling the entire chain from source to path to response, we can overcome the limitations of single hardware or software optimization. From structural optimization to individual vibration and noise control, from vehicle frequency avoidance strategies to environmental chamber simulation verification, we can greatly reduce the risk of individual components and the R&D cycle.

[0045] 2. By optimizing start-stop strategies and reducing the frequency of fluctuations caused by the compressor crossing the resonance zone during startup and shutdown, NVH and thermal management performance are optimized in a coordinated manner, and cooling capacity, energy consumption, vibration, and noise are calibrated simultaneously to avoid shortcomings in single-point optimization.

[0046] 3. Based on the test data of the three high (high temperature, high cold, and high altitude), by optimizing and adjusting the compressor operating speed at specific speeds and adjusting the compressor transition speed state time control, the NVH performance of the real vehicle air conditioner can be improved by adjusting the compressor speed strategy without increasing hardware and costs. This achieves the optimal global balance between air conditioning performance and driving comfort, and meets the development requirements of NVH ride comfort.

[0047] 4. Low cost and high compatibility: Adaptive dynamic optimization is performed by establishing high-speed maps, plateau maps, and cold-weather maps. The method of dynamically calibrating compressor operating parameters through parameterized maps solves the conflict between air conditioning performance and NVH under extreme operating conditions. Attached Figure Description

[0048] Figure 1 This is a flowchart of the dynamic calibration method for NVH performance of automotive air conditioning compressors according to the present invention;

[0049] Figure 2 This is a comparison chart of the target sound pressure level in the driver's right ear by the vehicle's compressor sweep frequency and the measured value of competing vehicles;

[0050] Figure 3 This is a comparison chart of the target vibration of the driver's steering wheel by the whole vehicle compressor sweep frequency and the measured values ​​of competing vehicles;

[0051] Figure 4 This is a vehicle map setting diagram of a competitor's compressor. Detailed Implementation

[0052] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0054] Firstly, such as Figure 1As shown, this embodiment of the invention provides a method for dynamic calibration of the NVH performance of an automotive air conditioning compressor, including the following steps:

[0055] S1. Compressor selection and bracket design: lightweight structural design based on performance requirements and installation space limitations;

[0056] S2. NVH analysis target setting for compressor: determine the target frequency range of the compressor bracket assembly modal, and avoid the frequency of external excitation sources and the compressor's own operating frequency.

[0057] S3. NVH analysis of the compressor bracket assembly: establish a finite element model for modal analysis, and verify the modal natural frequencies and dynamic stiffness of the mounting points;

[0058] S4. NVH test simulation benchmarking of compressor bracket assembly, and correction of simulation model through actual measurement data;

[0059] S5. NVH noise test control of individual compressors: Based on the compressor displacement selection range and maximum speed, set noise test parameters, including microphone installation position, exhaust pressure, intake pressure and speed, and control the frame noise within the target range.

[0060] S6. Set the vehicle noise and vibration target for the compressor, and combine the compressor frequency sweep test and subjective evaluation results to formulate the dynamic step target for the noise in the driver's right ear in the front row of the vehicle and the dynamic vibration target for the steering wheel in the vehicle.

[0061] S7. Compressor vehicle noise and vibration test: Based on the set target, the control level of the HVAC system blower is determined in conjunction with the blower. Under different blower levels, the compressor speed is controlled to complete the steady speed test and obtain the sound pressure level of the driver's right ear and the steering wheel vibration curve.

[0062] S8. Compressor vehicle noise and vibration avoidance frequency design, and formulate resonance frequency avoidance strategy; based on the vibration and noise target of the sweep frequency test and the obtained in-vehicle sound pressure level and vibration acceleration curve, formulate the resonance frequency that the air conditioning compressor needs to avoid in the speed increase range, and lock the idle speed condition avoidance design and the maximum compressor speed limit as the basic input for software calibration.

[0063] S9. Compressor start-stop calibration adopts a soft start / soft stop control strategy, which controls the compressor speed through a motor frequency conversion control drive strategy and dynamically adjusts the start-stop timing in combination with the overall vehicle status.

[0064] S10. Optimize the vehicle calibration strategy for environmental chamber simulation test, and dynamically adjust the compressor calibration strategy under simulated working conditions;

[0065] S11. The vehicle calibration strategy is locked in the environmental chamber simulation test. Based on the dynamically fine-tuned compressor calibration strategy, the vibration and noise test results of the vehicle air conditioning system compressor and the subjective evaluation results are carried out to determine the final compressor calibration strategy.

[0066] S12, the operating conditions of the high-temperature, high-altitude, and high-cold-weather test compressor were determined, and road tests were conducted in high-temperature, high-altitude, and high-temperature environments;

[0067] S13. Dynamic NVH calibration optimization of the high-altitude, high-temperature, high-humidity test compressor: Based on the dynamic calibration, adaptive strategies for high-altitude, high-humidity, high-temperature environments are formulated. The compressor parameters are dynamically adjusted according to vehicle speed and load. The cooling capacity, energy consumption, vibration, and noise are calibrated simultaneously to determine the dynamic NVH calibration strategy for the high-altitude, high-humidity, high-temperature test compressor.

[0068] S14. Acceptance of dynamic NVH calibration strategy for high-temperature, high-humidity, and high-temperature test compressors shall be conducted in accordance with the preset acceptance standards.

[0069] Specifically, in this embodiment of the invention, a dynamic control method for a compressor based on NVH performance parameter calibration is provided. In particular, it relates to a control method and device for dynamically adjusting the operating state of the compressor based on vehicle speed and air conditioning load. It is applicable to various working conditions such as driving and idling, and is used to balance cooling performance, energy consumption and NVH (noise, vibration, and harshness) comfort, so as to achieve the global optimal balance between air conditioning cooling performance and driving comfort.

[0070] In this embodiment of the invention, a method is provided to dynamically calibrate compressor operating parameters through parameterized mapping. Combining high-temperature, high-cold, and high-altitude test data, the method optimizes and adjusts the compressor operating speed at specific speed settings and adjusts the compressor transition speed state time control. Without increasing hardware or costs, the method improves the NVH performance of the vehicle's air conditioning by adjusting the compressor speed strategy, achieving a globally optimal balance between air conditioning performance and ride comfort, and meeting the development requirements for NVH ride comfort.

[0071] In this embodiment of the invention, a high-temperature environment is typically defined as an ambient temperature ≥ 40°C; a cold environment is generally defined as an ambient temperature ≤ -30°C; and an environment with an altitude ≥ 2000 meters is typically defined as a plateau environment, in which the air is thin and parameters such as the compressor suction pressure will change.

[0072] In this embodiment of the invention, in step S1 above, the performance indicators include compressor cooling capacity, power consumption, and speed range; the installation space limitations include the length, width, and height dimensions of the engine compartment and the interface location; and the lightweight structural design uses aluminum alloy materials.

[0073] The automotive air conditioning compressor is mounted on a compressor bracket assembly, which is then mounted on the vehicle body. The automotive air conditioning compressor is located in the engine compartment. In step S1 above, it is necessary to clarify the performance requirements of the compressor, such as cooling capacity, power consumption, and speed range, lock in the structural design boundary conditions of the compressor, evaluate the length × width × height installation dimensions, shape limitations, and interface locations in the engine compartment, and select aluminum alloy material for structural design in conjunction with the requirements for lightweight components.

[0074] In this embodiment of the invention, in step S2 above, the target frequency range of the compressor bracket assembly modality is set, which needs to avoid the dual excitation frequencies of the engine and motor. The excitation source engine idles at 25Hz and runs at 200Hz at high speed, ±15% of the compressor's own operating frequency of 16.7-146.6Hz corresponding to the compressor speed of 1000-8800rpm. The CAE modal analysis target requirements are determined, and the modal requirement of the bracket and compressor assembly is ≥230Hz.

[0075] In this embodiment of the invention, in step S2 above, the NVH analysis target setting includes:

[0076] External excitation sources include engine idle speed 25Hz±15% and high speed 200Hz±15%;

[0077] The compressor's own operating frequency is 16.7-146.6Hz±15% corresponding to 1000-8800rpm;

[0078] Modal target frequency ≥230Hz.

[0079] In step S2 above, "engine idle speed 25Hz" means that the main excitation frequency of the engine's vibration is 25Hz when the engine is idling. "High speed 200Hz" means that the main excitation frequency is 200Hz when the engine is running at high speed. "Setting the excitation frequency fluctuation range to ±15%" means that the frequency range to be avoided is a fluctuation of 15% above and below the core frequency, i.e.:

[0080] The idle speed excitation frequency range is: 25Hz×(1-15%)~25Hz×(1+15%)=21.25Hz~28.75Hz;

[0081] High-speed excitation frequency range: 200Hz×(1-15%)~200Hz×(1+15%)=170Hz~230Hz.

[0082] In step S2 above, when the compressor speed is 1000 rpm, the corresponding frequency is 1000 ÷ 60 ≈ 16.7 Hz; when the speed is 8800 rpm, the corresponding frequency is 8000 ÷ 60 ≈ 146.6 Hz. This reflects the basic excitation frequency range generated by the compressor's own movement. In actual operation, the compressor's vibration frequency will deviate due to factors such as load fluctuations, component clearances, and installation errors. Therefore, the frequency range needs to be widened by 15% as a "frequency avoidance boundary".

[0083] The ±15% range for 16.7Hz is: 16.7×(1-15%)≈14.2Hz to 16.7×(1+15%)≈19.2Hz; the ±15% range for 146.6Hz is: 146.6×(1-15%)≈124.6Hz to 146.6×(1+15%)≈168.6Hz.

[0084] The actual influence range of the compressor's own operating frequency should be considered as 14.2-168.6Hz to avoid the modal frequency of the bracket assembly falling into this range and causing resonance.

[0085] In step S2 above, the excitation source (engine) and the corresponding excitation frequencies for two typical operating conditions (idle and high speed) are clearly identified, and the fluctuation range of the excitation frequency is defined, facilitating the calculation of the specific frequency avoidance interval. Furthermore, the correspondence between compressor speed and operating frequency is clarified, and an intuitive conversion is established through specific values, making it easier to understand the frequency range of the compressor's own excitation. A tolerance of "±15%" is set to define the allowable range of frequency deviation, providing a clear basis for frequency avoidance in subsequent modal design.

[0086] In this embodiment of the invention, in step S3 above, NVH analysis of the compressor bracket assembly is performed. A finite element simulation model of the compressor assembly (including the compressor housing, the compressor bracket assembly, and the moving parts inside the compressor) needs to be established, modal analysis is performed, the natural frequencies of the first 10 modes are identified, and the requirements of modal frequency avoidance and first-order elastic mode are ensured. At the same time, the average dynamic stiffness of the compressor bracket mounting point from 20 to 500 Hz is examined to be >1500 N / mm.

[0087] In this embodiment of the invention, the NVH analysis of the compressor bracket assembly in step S3 above includes:

[0088] Establish a finite element simulation model that includes the compressor housing, compressor support assembly, and moving parts of the compressor;

[0089] Verify the natural frequencies of the first 10 modes;

[0090] The installation point dynamic stiffness requirement is an average value of >1500N / mm for 20-500Hz.

[0091] In step S3 above, verifying the first 10 modal natural frequencies refers to verifying the first 10 natural frequencies of the compressor assembly. Each mode corresponds to a specific vibration pattern and a natural frequency. Generally, lower-order modes (1-10) have higher vibration energy and are more likely to resonate with external excitations (such as engine vibration or the compressor's own operating frequency), thus they are the focus of NVH performance verification. By verifying whether the first 10 modal natural frequencies avoid the critical excitation frequency range, resonance can be avoided, improving the effectiveness of the analysis results.

[0092] Furthermore, requirements are set for the dynamic stiffness of the mounting points connecting the compressor assembly to the vehicle body within a frequency range of 20-500Hz, with an average value greater than 1500N / mm. The frequency range of 20-500Hz covers the main excitation frequencies commonly encountered in automotive applications, ensuring that the mounting points are not prone to noise or vibration transmission due to deformation within this range. This also prevents localized resonance caused by excessively low dynamic stiffness in a particular frequency band, and the overall performance is assessed by averaging the values.

[0093] In this embodiment of the invention, in step S4 above, NVH test simulation benchmarking of the compressor bracket assembly is performed, the modal and dynamic stiffness tests of the compressor bracket assembly sample are completed, the natural frequency and mode shape of the compressor assembly in the vehicle state are identified, the simulation data are compared, and the analysis error needs to be controlled within ±5%. Otherwise, the model boundary conditions need to be corrected and continuously optimized.

[0094] Step S4 above describes the process and requirements for testing and simulation benchmarking of the compressor bracket assembly. First, a physical prototype of the compressor bracket assembly is made, and then the prototype is subjected to the following two tests:

[0095] (1) Modal testing: The natural frequencies and mode shapes (vibration modes) of the sample are measured using instruments;

[0096] (2) Dynamic stiffness test at mounting point: Measure the dynamic stiffness of the mounting point of the sample at different frequencies, corresponding to the simulation analysis index in step S3;

[0097] Then, the sample is assembled onto the vehicle and its natural frequency and mode shape are tested in the vehicle state, taking into account the constraints of the vehicle body and other components.

[0098] Finally, the actual data obtained from the above experiments are compared with the theoretical data (modal frequencies, dynamic stiffness, and mode shapes) calculated by the finite element simulation model in step S3. After comparison, the error between the experimental data and the simulation data needs to be calculated. The error must be controlled within ±5%. If it exceeds this error range, it indicates that the boundary conditions of the simulation model (such as material properties, connection stiffness, constraint methods, etc.) deviate from the actual situation. The model needs to be corrected and the simulation needs to be repeated until the error meets the standard.

[0099] In this embodiment of the invention, in step S5 above, the compressor unit NVH noise test control is performed. Based on the compressor displacement selection range ≥27cm3 / r and the continuous maximum allowable speed Rmax is 8800rpm, the noise microphone is installed 15cm directly above the center of the compressor, the exhaust pressure is set to 1.50±0.02MPa(abs), the intake pressure is set to 0.3±0.005MPa(abs), the speed is set to 3000 / 4000 / 5000rpm, and the bench noise target is controlled to be ≤75 / 85 / 90dB(A) respectively.

[0100] Step S5 above describes the control conditions, test parameters, and performance targets for the compressor unit NVH noise test, verifying the compressor's noise level through standardized testing. The selection range for the compressor used in the test is defined as a displacement ≥ 27cm³. 3 The maximum permissible speed for continuous compressor operation is 8800 rpm. The requirements for the test environment and equipment settings are as follows:

[0101] (1) Noise collection location: The microphone for collecting noise is fixed 15cm directly above the center of the compressor in the test;

[0102] (2) The discharge pressure (pressure of refrigerant discharged by the compressor) during the test was set to 1.50±0.02MPa(abs), where abs represents absolute pressure;

[0103] (3) The suction pressure (pressure of refrigerant drawn into the compressor) during the test was set to 0.3±0.005MPa (abs).

[0104] During the test, the compressor was installed on the test bench and tested under three typical operating conditions with compressor speeds of 3000 rpm, 4000 rpm, and 5000 rpm. The target noise level for the test bench at the corresponding speeds was ≤75 dB(A), ≤85 dB(A), and ≤90 dB(A).

[0105] In this embodiment of the invention, in step S6 above, the vehicle noise and vibration targets for the compressor are set by combining the compressor frequency sweep test and subjective evaluation results. The dynamic step target for noise in the driver's right ear in the front row is set as follows: 1000-3000rpm@42dB(A), 3000-5000rpm@43dB(A), 5000-6000rpm@45dB(A), 6000-7000rpm@47dB(A), 7000-8000rpm@50dB(A); the dynamic vibration step target for the steering wheel is set as: 1000-3000rpm@0.2m / s². 2 3000-5000rpm@0.4m / s 25000-7000rpm@0.4m / s 2 7000-8800rpm@0.5m / s 2 .

[0106] In step S6 above, a dynamic, stepped target for compressor noise and vibration in the vehicle state is set by combining compressor frequency sweep testing and subjective evaluation standards. This primarily involves defining the noise and vibration limits perceived by the driver based on different compressor speed ranges. The compressor frequency sweep test involves continuously varying the compressor speed within a certain range and measuring the changes in noise and vibration with speed. Furthermore, the test focuses on the driver's right ear and the steering wheel—the two locations where the user most directly perceives noise and vibration—ensuring a strong correlation between the target and the user experience.

[0107] In step S6 above, a dynamic stepped noise target for the driver's right ear in the front row of the vehicle was established, divided according to the compressor speed range, with each range corresponding to a noise limit (dB(A) is the A-weighted sound pressure level, simulating the sensitivity of the human ear to mid-to-high frequency sounds):

[0108] When the compressor speed is between 1000-3000 rpm, the noise level at the driver's right ear must be ≤42 dB(A);

[0109] Speed ​​3000-5000rpm, noise level ≤43dB(A);

[0110] When the speed is 5000-6000 rpm, the noise level must be ≤45dB(A);

[0111] Noise level must be ≤47dB(A) at 6000-7000rpm.

[0112] When the speed is 7000-8000 rpm, the noise level must be ≤50dB(A).

[0113] In step S6 above, a dynamic vibration step target for the steering wheel inside the vehicle was established, divided according to the compressor speed range, with each range corresponding to a vibration acceleration limit for the steering wheel:

[0114] When the compressor speed is 1000-3000 rpm, the vibration acceleration of the steering wheel at the 12 o'clock position must be ≤0.2 m / s². 2 ;

[0115] When the compressor speed is 3000-5000 rpm and 5000-7000 rpm, the vibration acceleration must be ≤0.4 m / s². 2 ;

[0116] When the compressor speed is 7000-8800 rpm, the vibration acceleration must be ≤0.5 m / s². 2 .

[0117] In this embodiment of the invention, in step S7 above, a vehicle noise and vibration test of the compressor is performed. Based on the target set in step S6, the control gear is determined in conjunction with the blower of HVAC Xigong. Under different gears of the vehicle blower, the compressor speed is controlled to achieve a stable speed of 1000-8800rpm. The air conditioning compressor speed is tested from the lowest Rmin to the highest Rmax stable operating speed in increments of 100rpm. The sound pressure level of the driver's right ear and the vibration curve SPL of the steering wheel at the 12 o'clock position are obtained.

[0118] In step S7 above, the operation process, control conditions and data acquisition targets of the compressor sample vehicle noise and vibration test are described. Under the whole vehicle environment, combined with the working status of other components of the air conditioning system (such as the blower of the air conditioning system), the noise and vibration performance of the compressor at different speeds is fully verified.

[0119] Furthermore, the test must be conducted in accordance with the dynamic stepped targets set in step S6 (such as driver's right ear noise and steering wheel vibration limits) to ensure that the test results can be directly compared with the targets. During the test, the blower (the blower is the fan responsible for delivering cold / hot air into the vehicle) must be used in conjunction to determine the control level. The blower must be set to different levels to simulate different airflow scenarios when users actually use the air conditioner, so as to avoid the results being one-sided due to testing only a single blower state, and to ensure the comprehensiveness of the test and the validity of the results.

[0120] In step S7 above, the compressor speed control method is as follows: under each blower speed setting, the compressor speed is controlled to operate within the range of 1000-8800 rpm; and the compressor speed adjustment method is to increase by 100 rpm each time, that is, starting from the lowest stable operating speed (Rmin) of the compressor, increasing by 100 rpm each time (e.g., 1000 rpm → 1100 rpm → 1200 rpm…) until the highest stable operating speed (Rmax = 8800 rpm), ensuring that the key speed points of the entire operating range are covered.

[0121] In step S7 above, during the test, the sound pressure level of the driver's right ear is collected, that is, the noise level at the driver's ear position (corresponding to the noise target in step S6), forming the sound pressure level data of the driver's right ear; the vibration curve SPL (vibration acceleration level curve) of the steering wheel at the 12 o'clock position is collected, reflecting the change of vibration intensity of the steering wheel at the position most easily perceived by the driver (12 o'clock position) with the rotation speed (corresponding to the vibration target in step S6), and the steering wheel vibration curve is obtained.

[0122] In this embodiment of the invention, in step S8 above, the vehicle noise and vibration avoidance design of the compressor is carried out. Based on the vibration and noise target of the compressor sweep frequency test in step S6, the in-vehicle sound pressure level and vibration acceleration curve SPL of the steering wheel as the compressor speed changes are obtained through step S7. The resonance frequency that needs to be avoided in the increasing range of Rmin to Rmax of the air conditioning compressor is determined. The idle speed condition is locked according to the frequency avoidance design of 3200-3400rpm, and the maximum compressor speed limit of 8300rpm is used as the basic input for software calibration.

[0123] In step S8 above, the idling condition is designed to avoid the frequency of 3200-3400rpm, and the maximum speed of the compressor is set to 8300rpm.

[0124] In step S8 above, resonance risk zones are identified using preliminary test data. These zones are then avoided by controlling the compressor speed, reducing vibration and noise amplification. The vibration and noise dynamic targets set in step S6 are used as a benchmark: 1000-3000rpm@42dB(A), 3000-5000rpm@43dB(A), 5000-6000rpm@45dB(A), 6000-7000rpm@47dB(A), 7000-8000rpm@50dB(A); the target for dynamic vibration steps in the steering wheel inside the vehicle is: 1000-3000rpm@0.2m / s². 2 3000-5000rpm@0.4m / s 2 5000-7000rpm@0.4m / s 2 7000-8800rpm@0.5m / s 2 The system clearly defines the performance red lines that cannot be exceeded. Simultaneously, combining the measured data from step S7, the in-vehicle sound pressure level curve and steering wheel vibration acceleration curve (SPL) obtained in S7 visually indicate which speed ranges will experience noise or vibration peaks (i.e., areas where resonance may occur). Based on these curves, these speed ranges prone to resonance are identified throughout the entire range from the compressor's lowest stable speed (Rmin) to its highest stable speed (Rmax). Frequency avoidance design rules are then formulated to ensure the compressor speed "avoids" or "quickly passes through" these ranges, preventing continuous resonance. Specific frequency avoidance design rules include:

[0125] (1) When locked in an idling scenario, 3200-3400rpm is a dangerous range that is prone to resonance. Therefore, the compressor speed should be controlled to prevent it from staying in this speed range for a long time during the design.

[0126] (2) Limit the compressor's maximum speed to 8300 rpm (lower than its continuous maximum allowable speed of 8800 rpm, see step S5), because excessive noise or vehicle vibration occurs above 8300 rpm. This speed limit will serve as the basis for software calibration—that is, through the vehicle control system's software program (such as the program of the air conditioning compressor control module), the compressor speed will be forced not to exceed this value, thus mitigating risks at the source. If the software program reads these parameters and monitors the speed in real time during compressor operation, it will automatically control the speed to quickly cross the threshold when it approaches 3200 rpm, or limit it to further increase when it reaches 8300 rpm, ultimately achieving the effect of frequency avoidance.

[0127] In this embodiment of the invention, in step S9 above, compressor start-stop calibration is performed, and a soft start / soft stop control strategy is optimized. The motor frequency conversion control drive strategy is used to achieve smooth speed increase and decrease to avoid sudden torque changes. When starting, a ramp-type speed increase is used, and when stopping, the electromagnetic force is gradually unloaded. The start-stop timing is dynamically adjusted in combination with the overall vehicle status (such as engine speed and vehicle speed). When the vehicle accelerates, the compressor start is delayed to avoid the superposition of power system load.

[0128] Step S9 above describes the strategy and purpose of compressor start-stop calibration. By optimizing the dynamic process of compressor start-up and shutdown, transient noise, vibration, and interference with the vehicle's powertrain are reduced. Sudden compressor start-up or shutdown can cause a sudden change in motor torque, leading to severe vibration and impact noise, and may also cause mechanical impact on the air conditioning system piping and supports. Therefore, soft start / soft stop control is adopted, using motor inverter technology to ensure smooth compressor speed increases and decreases.

[0129] In step S9 above, soft start is a ramp-up speed increase, where the speed gradually increases in a ramp-like manner during startup (e.g., slowly accelerating from 0 to the target speed, rather than jumping instantaneously); soft stop is a gradual unloading of the electromagnetic force (the driving force of the motor), where the speed is slowly reduced to a stop by gradually decreasing the electromagnetic force during shutdown, avoiding the impact of sudden power failure.

[0130] In step S9 above, the start-stop timing of the compressor is dynamically adjusted based on the overall vehicle status, including engine speed and vehicle speed; the compressor start-up is delayed during vehicle acceleration. The compressor's start-up and shutdown not only affect its own NVH performance but also increase the engine load. Therefore, the start-stop timing needs to be flexibly adjusted according to the overall vehicle status. For example, delaying compressor start-up during vehicle acceleration: when the driver accelerates by pressing the accelerator, the engine needs to prioritize providing power to drive the vehicle. If the compressor starts at this time, it will increase the engine load, potentially leading to insufficient acceleration or engine speed fluctuations, which in turn will cause vibration and noise. By delaying the compressor start-up, the power load is avoided, balancing driving dynamics and NVH performance.

[0131] In this embodiment of the invention, in step S10 above, the vehicle calibration strategy is optimized for environmental chamber simulation tests. Based on the frequency avoidance design rules obtained in step S8 and the compressor start-stop calibration strategy obtained in step S9, environmental chamber simulation tests are conducted. Cooling standard operating condition tests are performed, mainly including parking, vehicle speed of 50-80km / h, ambient temperature of 40℃, and data collection of average air outlet temperature and average head temperature at different times. Heating standard operating condition tests are performed, mainly including parking, vehicle speed of 40-60km / h, ambient temperature of -20℃, and data collection of average front / rear foot temperature at different times. Defrosting standard operating condition tests are performed, mainly including ambient temperature of -18±3℃, confirmation of defrosting effect in areas A and B at different times. Defrosting and defogging standard operating condition simulation tests are performed, with ambient temperature of -3±1℃, confirmation of defrosting and defogging effect in areas A and B and rearview mirror at different times. The compressor calibration strategy is dynamically fine-tuned in conjunction with the environmental chamber simulation tests.

[0132] Step S10 above describes the complete process of optimizing the vehicle compressor calibration strategy through environmental chamber simulation testing. In a controlled laboratory environment, air conditioning usage scenarios under different climates and operating conditions are simulated to verify the effectiveness of the previously established compressor control strategies (frequency avoidance, start-stop, etc.). Based on the test results, the strategy is fine-tuned to ensure that the compressor can meet both thermal management requirements and NVH performance under various environments. This involves simulating real-world usage scenarios in an environmental chamber to test the actual effect of the compressor calibration strategy. If thermal management performance (such as cooling speed, defrosting efficiency) or NVH performance is found to be substandard, the compressor calibration strategy is dynamically fine-tuned to ultimately achieve a balance between NVH performance and thermal management performance.

[0133] In step S10 above, four typical scenarios were set up as standard operating conditions to verify the NVH performance of the air conditioner's core functions (cooling, heating, defrosting, and defogging) under the compressor calibration strategy:

[0134] (1) Refrigeration standard operating condition test:

[0135] Simulated high-temperature environment: The ambient temperature of the environmental chamber is set to 40℃;

[0136] Vehicle statuses covered: parked, driving at a speed of 50-80km / h;

[0137] The test included collecting the average temperature of the air conditioning vents (reflecting cooling efficiency) and the average head temperature of the occupants (reflecting perceived cooling effect) at different durations (e.g., 5 minutes, 10 minutes, 30 minutes) to verify whether the compressor's cooling capacity at high temperatures matched the control strategy.

[0138] (2) Heating standard operating condition test:

[0139] Simulating a frigid environment: The ambient temperature of the environmental chamber is set to -30℃;

[0140] Vehicle statuses covered: parked, driving at a speed of 40-60km / h;

[0141] The test included collecting the average temperature of the front and rear foot areas for different durations (in winter, warm air mostly blows out from the feet, reflecting the heating effect) to verify the compressor's heating coordination capability at low temperatures (some air conditioning systems require compressor assistance for heating).

[0142] (3) Defrosting standard operating condition test:

[0143] Simulated frost environment: The ambient temperature of the environmental chamber is set to -18±3℃;

[0144] The test included: confirming the defrosting area ratio of the windshield "A and B zones" (A zone is the core area of ​​the driver's vision, and B zone is the secondary area) at different durations (e.g., the defrosting rate of A zone must be ≥80% within 10 minutes), and verifying the defrosting efficiency of the compressor at low temperatures (defrosting requires the air conditioning system to output high-temperature air, which depends on the compressor speed control).

[0145] (4) Defogging standard operating condition test:

[0146] Simulating a humid and cold fogging environment: The ambient temperature of the environmental chamber is set to -3±1℃, which easily leads to a mixture of fog and frost.

[0147] The test included: confirming the defrosting and defogging area of ​​the windshield in zones A and B at different durations, as well as the defrosting and defogging effect of the rearview mirror (to ensure driving visibility), and verifying the comprehensive performance of the compressor in high humidity and low temperature environments.

[0148] If a certain scenario fails to meet the standards through the above operating condition tests, the calibration parameters will be adjusted accordingly, such as relaxing the restrictions on a certain speed range or optimizing the speed slope of soft start-stop, so as to achieve a balance between NVH not exceeding the standard and thermal management meeting the standard in the environmental chamber.

[0149] In this embodiment of the invention, in step S11 above, the vehicle calibration strategy for the environmental chamber simulation test is locked, and the vibration and noise test and subjective evaluation of the vehicle air conditioning system compressor are carried out according to the test dynamic fine-tuning compressor calibration strategy in step S10, and the NVH and thermal management performance are comprehensively considered.

[0150] In step S11 above, based on the dynamic fine-tuning in step S10, the optimal strategy is confirmed through final verification to ensure that the compressor achieves a balance between NVH and thermal management performance. Step S10 involved dynamic fine-tuning of the compressor calibration strategy through environmental chamber simulation tests. Step S11 requires further verification based on this fine-tuned compressor calibration strategy to provide a basis for determining the final compressor calibration strategy. Under full vehicle conditions, the compressor's vibration and noise performance are tested again to verify whether the fine-tuned strategy still meets the NVH targets set in step S6. During subjective evaluation, staff are required to score the comfort of in-vehicle noise and vibration to ensure that the targets conform to objective data and closely reflect the actual experience of car users, compensating for user experience that objective data cannot fully reflect. Simultaneously, it is confirmed whether the fine-tuned strategy still meets the thermal management requirements of various operating conditions in step S10, avoiding sacrificing the core functions of the air conditioning system for NVH optimization.

[0151] Through the verification of step S11 above, and considering the comprehensive NVH and thermal management performance—that is, when the fine-tuned compressor calibration strategy simultaneously meets the following conditions: ① vibration and noise meet the target; ② subjective evaluation is good; ③ cooling, heating, defrosting and other functions meet the standards—then the strategy can be locked as the benchmark strategy for the subsequent high-temperature, high-humidity and high-temperature test steps, and no further significant adjustments will be made.

[0152] In this embodiment of the invention, in step S12 above, the verification working conditions of the high-altitude, high-cold, and high-temperature test compressor are determined. Based on the compressor's usage scenarios, high-temperature, high-cold, and high-altitude road tests are carried out. The driving scenarios include idling, high speed, and rapid acceleration. Combined with the characteristics of pickup trucks, a high-temperature durability test of continuous operation at 50°C for 8 hours in a desert environment is added, as well as a low-temperature cold start verification of the compressor's lubrication performance at -30°C. Test data are collected, and a five-dimensional parameterized dynamic multi-dimensional map architecture of temperature, altitude, vehicle speed, compressor speed, and displacement in the dimensions of "environment-working condition-control" is constructed to support real-time dynamic calibration.

[0153] In step S12 above, the robustness of the compressor calibration strategy is verified by covering extreme environments and typical usage scenarios. This verifies the compressor's ability to adapt to various complex conditions and builds a dynamic parameter model to support real-time compressor control. "High-altitude, high-temperature, and high-humidity testing" is a core method in the automotive industry for verifying the extreme environmental adaptability of components. Here, it is used to verify the compressor's NVH performance, thermal management capabilities, and reliability under the most stringent conditions, ensuring that the calibration strategy (i.e., the strategy locked in step S11) still works effectively in actual extreme scenarios. By designing targeted tests, deviations between laboratory simulations and actual use are avoided.

[0154] In step S12 above, the driving scenarios include idling, high speed, and rapid acceleration; the vehicle is a pickup truck; the added specific environmental tests are a high-temperature durability test of continuous operation at 50℃ for 8 hours in a desert environment, and a low-temperature cold start verification of the compressor lubrication performance at -30℃.

[0155] The vehicle was driven in a desert environment with a temperature of 50℃, and the compressor ran continuously for 8 hours to simulate extreme high temperature and dusty conditions, verifying the durability of the compressor under long-term high temperature operation. The vehicle was driven in a low temperature environment of -30℃ to verify the cold start of the compressor, simulating an extremely cold environment. The focus was on testing the compressor's lubrication performance to ensure that it could operate normally during cold starts and that vibration and noise were controllable.

[0156] In step S12 above, the construction of the five-dimensional parameterized dynamic multidimensional Map architecture involves building parameter mapping relationships from five key dimensions, including ambient temperature, altitude, vehicle speed, compressor speed, and compressor displacement. A dynamic parameter control model for the compressor is constructed, and a correspondence rule of "environment-operating condition-compressor parameters" is established to form a five-dimensional Map table to support real-time dynamic calibration. That is, when the vehicle is driving, the control system can quickly query the optimal compressor speed and displacement parameters through the Map architecture based on real-time data such as current temperature, altitude, and vehicle speed to achieve dynamic adaptation without relying on preset fixed strategies, thus greatly improving adaptability.

[0157] The construction of the five-dimensional parameterized dynamic multi-dimensional map architecture involves establishing a real-time correspondence between the five input parameters (temperature, altitude, vehicle speed, compressor speed, and displacement μ) and the compressor's optimal control parameters (such as target speed, frequency, and refrigerant flow rate). This transforms the sample data collected during testing into a structured five-dimensional map table. While the vehicle is in motion, the controller collects the five-dimensional parameters in real time and uses the map table to output the compressor's optimal control parameters.

[0158] In this embodiment of the invention, in step S13 above, dynamic NVH calibration optimization of the high-temperature, high-humidity, and high-temperature test compressor is performed. Based on the dynamic calibration in step S12, adaptive strategies for high-temperature, high-humidity, and high-temperature environments are formulated respectively. The compressor displacement is dynamically adjusted according to vehicle speed and load. At high vehicle speed, air cooling is used first to reduce the compressor load. When the vehicle speed is >80km / h, the five-dimensional map table is activated: the compressor speed is limited to 6000rpm / s, and high-frequency noise is suppressed by increasing the PWM frequency to 18kHz in high-temperature environments. In cold environments, the five-dimensional map table is activated, and the compressor speed is reduced and soft-started for adaptive adjustment. The initial speed is 800RPM, the displacement is 10%, and the preheating lasts for 3 minutes. In high-altitude environments, the five-dimensional map table is activated: the compressor speed is reduced by 12%, the refrigerant flow is increased by 20%, and the cooling capacity, energy consumption, vibration, and noise are calibrated simultaneously to determine the compressor software calibration strategy for high-temperature, high-humidity, and high-temperature environments.

[0159] In step S13 above, based on the five-dimensional parameterized Map architecture constructed in step S12, customized parameter adjustments are made to ensure that the compressor meets NVH requirements while also taking into account core performance aspects such as cooling / heating efficiency and energy consumption in extreme environments. For the specific characteristics of the three extreme environments—high temperature, high cold, and high altitude—adaptive environmental strategies are formulated separately. This involves dynamically adjusting the compressor's operating parameters according to environmental characteristics to avoid performance imbalances caused by using a uniform strategy in a particular environment.

[0160] In step S13 above, the adaptive strategy for high-altitude, high-temperature, and high-temperature environments includes: at high vehicle speeds, prioritizing air cooling to reduce compressor load; when the vehicle speed is set to >80km / h, activating the five-dimensional map table: limiting the compressor speed to no more than 6000rpm / s; in high-temperature environments, suppressing high-frequency noise by increasing the PWM frequency to 18kHz; in cold-weather environments, activating the five-dimensional map table, reducing the compressor speed for soft-start adaptive adjustment, setting the initial speed to 800RPM and the displacement to 10%, and preheating for 3 minutes; in high-altitude environments, activating the five-dimensional map table, reducing the compressor speed by 12%, and increasing the refrigerant flow by 20%.

[0161] Through the optimization of the above-mentioned environment-specific strategies, a three-high test calibration strategy for compressor software is formed to ensure that the compressor can achieve NVH and core performance standards in high temperature, high cold, and high altitude environments.

[0162] In this embodiment of the invention, in step S14 above, the dynamic calibration strategy of the high-temperature, high-humidity, and high-air quality test compressor is accepted, and the dynamic calibration acceptance of the NVH performance of the automotive air conditioning compressor is completed. The subjective evaluation criteria are: in-vehicle start-stop noise ≤40dB(A), no abnormal noise, and steering wheel vibration acceleration ≤0.2m / s². 2 (20-200Hz frequency band) is the acceptance standard.

[0163] In step S14 above, through quantitative indicators and subjective evaluation, it is confirmed whether the dynamic calibration strategy of the high-temperature, high-altitude, and high-humidity test compressor optimized in step S13 meets the NVH performance requirements of the whole vehicle, ensuring that the noise and vibration performance of the compressor meets the standards in extreme environments. The dynamic calibration strategies of the compressor formulated in step S13 for high-temperature, high-altitude, and high-cold environments are verified to verify whether these strategies can stably achieve the NVH performance targets in actual operation, avoid noise and vibration exceeding the standards due to extreme environments, and ensure that the user experience meets the design expectations.

[0164] In step S14 above, the acceptance criteria are divided into objective quantitative indicators and subjective evaluation indicators. The combination of the two is used to determine whether the strategy is qualified.

[0165] Objective quantitative indicators include:

[0166] (1) In-vehicle start-stop noise ≤ 40dB(A); The A-weighted sound pressure level measured in the vehicle (usually at the driver's right ear position) during the compressor start-up and shutdown moments (the stage most prone to generating impact noise) must be ≤ 40dB(A). 40dB(A) is an extremely low noise level, ensuring that users can hardly perceive the noise during the start-stop process;

[0167] (2) Steering wheel vibration acceleration ≤ 0.2 m / s² 2 (20-200Hz frequency band); In the critical vibration frequency band of 20-200Hz (where the human body is most sensitive to vibration), the vibration acceleration of the steering wheel at the 12 o'clock position must be ≤0.2m / s². 2 This specification ensures that compressor vibrations are not transmitted through the vehicle body to the steering wheel, preventing the driver from experiencing noticeable vibrations.

[0168] Subjective evaluation indicators include:

[0169] The evaluation personnel (such as NVH engineers and test drivers) make a subjective judgment on the entire operation of the compressor (including start-up, shutdown, and stable operation) to confirm that there are no "noises that are different from normal working sounds", thus making up for the sound quality experience that cannot be covered by objective data.

[0170] Through the above verification, it is confirmed whether the dynamic calibration strategy in step S13 has achieved the goal of not degrading NVH performance under extreme environments—that is, regardless of high temperature, high cold or high altitude environments, the noise and vibration performance of the compressor can be stably controlled within the acceptance standard.

[0171] Secondly, embodiments of the present invention also provide a dynamic calibration system for the NVH performance of an automotive air conditioning compressor, comprising:

[0172] The processor module is used to execute the calibration method described in the above embodiments;

[0173] The memory module stores the finite element model, experimental data, and calibration strategy parameters.

[0174] The control module enables soft start / soft stop control, dynamic speed adjustment, and five-dimensional Map architecture application.

[0175] The data acquisition module obtains bench noise data, actual vehicle vibration data, and environmental chamber test data.

[0176] This invention optimizes and tunes the air conditioning system from the perspective of NVH performance calibration strategy development. It systematically optimizes the source, path, and response aspects to ensure that the compressor and its support units meet NVH and vibration noise targets. It sets vehicle-wide vibration noise targets for the compressor, locks in the compressor's vehicle-wide noise and vibration frequency avoidance design, and optimizes the start-stop strategy to reduce the frequency of fluctuations caused by the compressor crossing resonance zones during startup and shutdown. This invention uses a parametric mapping method to dynamically calibrate compressor operating parameters, combined with high-temperature, high-altitude, and high-temperature (HATA) test data. By optimizing and adjusting the compressor's operating speed at specific speed settings and adjusting the compressor's transition speed state time control, it improves the NVH performance of the vehicle's air conditioning compressor by adjusting the compressor speed strategy without increasing hardware or cost. This achieves a globally optimal balance between air conditioning performance and ride comfort, meeting the development requirements for NVH and ride comfort.

[0177] Traditional methods often employ a linear design-experiment process, lacking dynamic feedback. The calibration method of this invention utilizes a multi-stage closed-loop design, including target setting (step S2), simulation analysis (step S3), experimental benchmarking (step S4), vehicle testing (step S7), environmental optimization (steps S10-S13), and acceptance (step S14). The results of each step inversely correct the preceding parameters, achieving dynamic iteration from virtual to physical and from individual components to the entire vehicle. This significantly improves the calibration accuracy of compressor NVH performance.

[0178] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A method for dynamic calibration of NVH performance of automotive air conditioning compressors, characterized in that, Including the following steps: S1. Compressor selection and bracket design: lightweight structural design based on performance requirements and installation space limitations; S2. NVH analysis target setting for compressor: determine the target frequency range of the compressor bracket assembly modal, and avoid the frequency of external excitation sources and the compressor's own operating frequency. S3. NVH analysis of the compressor bracket assembly: establish a finite element model for modal analysis, and verify the modal natural frequencies and dynamic stiffness of the mounting points; S4. NVH test simulation benchmarking of compressor bracket assembly, and correction of simulation model through actual measurement data; S5. NVH noise test control of individual compressors: Based on the compressor displacement selection range and maximum speed, noise test parameters are set, including microphone installation position, exhaust pressure, intake pressure and speed, to control the noise of individual compressor bench within the target range. S6. Set the vehicle noise and vibration target for the compressor, and combine the compressor frequency sweep test and subjective evaluation results to formulate the dynamic step target for the noise in the driver's right ear in the front row of the vehicle and the dynamic vibration target for the steering wheel in the vehicle. S7. Compressor vehicle noise and vibration test: Based on the set target, the control level of the HVAC system blower is determined in conjunction with the blower. Under different blower levels, the compressor speed is controlled to complete the steady speed test and obtain the sound pressure level of the driver's right ear and the steering wheel vibration curve. S8, compressor vehicle noise and vibration avoidance design, and formulate resonant frequency avoidance strategy; S9. Compressor start-stop calibration adopts a soft start / soft stop control strategy, which controls the compressor speed through a motor frequency conversion control drive strategy and dynamically adjusts the start-stop timing in combination with the overall vehicle status. S10. Optimize the vehicle calibration strategy for environmental chamber simulation test, and dynamically adjust the compressor calibration strategy under simulated working conditions; S11. The vehicle calibration strategy is locked in the environmental chamber simulation test. Based on the dynamically fine-tuned compressor calibration strategy, the vibration and noise test results of the vehicle air conditioning system compressor and the subjective evaluation results are carried out to determine the compressor calibration strategy. S12, the operating conditions of the high-temperature, high-altitude, and high-cold-weather test compressor were determined, and road tests were conducted in high-temperature, high-altitude, and high-temperature environments; S13. Dynamic NVH calibration optimization of the high-altitude, high-temperature, high-humidity test compressor: Based on the dynamic calibration, adaptive strategies for high-altitude, high-humidity, high-temperature environments are formulated. The compressor parameters are dynamically adjusted according to vehicle speed and load. The cooling capacity, energy consumption, vibration, and noise are calibrated simultaneously to determine the dynamic NVH calibration strategy for the high-altitude, high-humidity, high-temperature test compressor. S14. Acceptance of dynamic NVH calibration strategy for high-temperature, high-humidity, and high-temperature test compressors shall be conducted in accordance with the preset acceptance standards.

2. The method for dynamic calibration of NVH performance of automotive air conditioning compressors according to claim 1, characterized in that, In step S1, the performance indicators include cooling capacity, power consumption, and speed range; the installation space limitations include the length, width, and height dimensions of the engine compartment and the interface location; the lightweight structural design uses aluminum alloy materials.

3. The method for dynamic calibration of NVH performance of automotive air conditioning compressors according to claim 1, characterized in that, The NVH analysis objectives include: External excitation sources include engine idle speed 25Hz±15% and high speed 200Hz±15%; The compressor's own operating frequency is 16.7-146.6Hz±15% corresponding to 1000-8800rpm; Modal target frequency ≥230Hz.

4. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, The NVH analysis of the compressor bracket assembly includes: Establish a finite element model that includes the shell, support, and moving parts; Verify the natural frequencies of the first 10 modes; The installation point dynamic stiffness requirement is an average value of >1500N / mm for 20-500Hz.

5. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S5, the compressor displacement selection range is ≥27cm. 3 / r, the maximum permissible speed Rmax is 8800rpm; the microphone is installed 15cm directly above the center of the compressor; the exhaust pressure is set to 1.50±0.02MPa(abs), and the intake pressure is set to 0.3±0.005MPa(abs); the speed is set to 3000 / 4000 / 5000rpm, and the bench noise target is ≤75 / 85 / 90dB(A) respectively.

6. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S6, the target dynamic noise levels for the driver's right ear in the front seat are: 1000-3000 rpm @ 42 dB(A), 3000-5000 rpm @ 43 dB(A), 5000-6000 rpm @ 45 dB(A), 6000-7000 rpm @ 47 dB(A), and 7000-8000 rpm @ 50 dB(A); the target dynamic vibration levels for the steering wheel are: 1000-3000 rpm @ 0.2 m / s 2 3000-5000rpm@0.4m / s 2 5000-7000rpm@0.4m / s 2 7000-8800rpm@0.5m / s 2 .

7. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S7, the compressor speed is tested from the lowest Rmin to the highest Rmax stable operating speed in increments of 100 rpm; the steering wheel vibration curve is the steering wheel 12 o'clock direction vibration curve SPL.

8. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S8, the idling condition is designed to avoid frequencies at 3200-3400rpm, and the maximum speed of the compressor is set to 8300rpm.

9. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S9, the soft start is a ramp-like acceleration, and the soft stop is a gradual unloading of the electromagnetic force; the vehicle status includes engine speed and vehicle speed; the compressor starts delayed when the vehicle accelerates.

10. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S12, the driving scenarios include idling, high speed, and rapid acceleration; the vehicle is a pickup truck, and the added specific environmental tests are a high-temperature durability test of continuous operation at 50°C for 8 hours in a desert environment, and a low-temperature cold start verification of the compressor lubrication performance at -30°C.

11. The method for dynamic calibration of NVH performance of an automotive air conditioning compressor according to any one of claims 1 to 3, characterized in that, In step S13, the adaptive strategy for high-altitude, high-temperature, and high-temperature environments includes: at high vehicle speeds, prioritizing air cooling to reduce compressor load; when the vehicle speed is set to >80km / h, activating the five-dimensional map table: limiting the compressor speed to no more than 6000rpm / s; in high-temperature environments, suppressing high-frequency noise by increasing the PWM frequency to 18kHz; in cold-weather environments, activating the five-dimensional map table, reducing the compressor speed for soft-start adaptive adjustment, setting the initial speed to 800RPM and the displacement to 10%, and preheating for 3 minutes; in high-altitude environments, activating the five-dimensional map table, reducing the compressor speed by 12%, and increasing the refrigerant flow by 20%.

12. A dynamic calibration system for the NVH performance of an automotive air conditioning compressor, characterized in that, include: Processor module, configured to perform the calibration method as described in any one of claims 1 to 11; The memory module stores the finite element model, experimental data, and calibration strategy parameters. The control module enables soft start / soft stop control, dynamic speed adjustment, and five-dimensional Map architecture application. The data acquisition module obtains bench noise data, actual vehicle vibration data, and environmental chamber test data.

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