New energy automobile electric drive NVH optimization method

Abstract

The invention relates to the technical field of new energy automobile electric drive NVH optimization, in particular to a new energy automobile electric drive NVH optimization method, which comprises the following steps of: extracting an actual measurement order, and judging whether an electric drive system is wrapped by an acoustic packet or not; sensing a plurality of amplitudes, and carrying out weighted summation and fusion on the plurality of amplitudes; when the acoustic packet is wrapped by the electric drive system, the average value of the multiple amplitudes is calculated as a comparison order, and when the acoustic packet is not wrapped by the electric drive system, the maximum amplitude in the multiple amplitudes obtained through weighted summation fusion is called out as the comparison order; respectively calculating a motor core characteristic order and each reduction ratio characteristic order of the speed reducer; judging the feature order to which the pair belongs, if the comparison order belongs to the motor core feature order, judging the stator order and the rotor order again, and outputting an optimization signal according to the judgment result; if the comparison order belongs to the speed reducer characteristic order, outputting a corresponding optimization signal; and after the reminding signal and the optimization signal are output, subjective evaluation is carried out.

Description

Technical Field

[0001] This invention relates to the field of NVH optimization technology for electric drive systems in new energy vehicles, and more specifically, to a method for optimizing NVH in electric drive systems of new energy vehicles. Background Technology

[0002] With the rapid development of the new energy vehicle industry driven by both technological iteration and market demand, consumers' demands for car comfort have evolved from basic driving convenience to higher levels of quietness and smoothness. Passengers' subjective comfort has not only become a core dimension for automakers to differentiate themselves, but also directly affects consumers' car purchase decisions. Models with excellent comfort performance are more likely to gain deep recognition and favor from consumers in the fierce market competition. As a key indicator of comfort, vehicle noise exhibits distinct characteristics in the field of new energy pure electric vehicles compared to traditional fuel vehicles. Pure electric vehicles replace traditional fuel engines with electric motor drive systems, and the speed of electric motors is generally much higher than that of fuel engines (some high-performance motors can reach peak speeds of over 15,000 rpm). During high-speed operation, the order noise (such as electromagnetic order noise of the motor and meshing order noise of the gear reducer) generated by electromagnetic forces and mechanical meshing (such as gear reducers) is more prominent. Moreover, the frequency distribution of this type of order noise is wider and more directional. It is not only easily perceived by passengers, but also generates complex vibration transmission paths due to the coupling effect between the motor and the vehicle structure. This leads to multiple challenges for electric drive NVH optimization, such as "difficulty in identifying noise sources, complex vibration transmission paths, and interference from the superposition of multiple order noises". In view of this, we propose a method for optimizing the NVH (noise, vibration, and harshness) of electric drive systems in new energy vehicles. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the electric drive system of new energy vehicles has insufficient overall vehicle comfort due to the high motor speed and significant first-order noise, and the difficulty in accurately locating the root cause of the problem by traditional NVH optimization methods, which makes it difficult to meet consumers' demand for a high-quality driving experience.

[0004] To achieve the above objectives, this invention provides a method for optimizing NVH (Noise, Vibration, and Harshness) in the electric drive system of new energy vehicles, comprising the following steps: setting up multiple sensors for collecting NVH signals, extracting multiple amplitude values ​​corresponding to the sampling time of each NVH signal, selecting the maximum amplitude value as the measured order, determining whether the electric drive system is encased in an acoustic package, and then outputting a reminder signal; sensing multiple amplitude values ​​corresponding to the sampling time of the NVH signals collected by multiple sensors, setting the vehicle center point, and weighting and summing multiple amplitude values ​​based on the distance between the vehicle center point and each sensor; when the electric drive system is encased in an acoustic package, calculating the average of the multiple amplitude values ​​as the comparison order; when it is not encased in an acoustic package... The process involves: selecting the largest amplitude value from multiple weighted summations as the comparison order; calculating the core characteristic order of the motor and the characteristic order of each reduction ratio of the reducer; determining the characteristic order to which the comparison order belongs; if the comparison order belongs to the core characteristic order of the motor, then determining the stator order and rotor order again, and outputting an optimization signal based on the determination result; if the comparison order belongs to the characteristic order of the reducer, then selecting the corresponding reduction ratio and outputting the corresponding optimization signal; after outputting the reminder signal and the optimization signal, a subjective evaluation is performed to determine whether the subjective evaluation passes; if the subjective evaluation passes, NVH optimization is completed; if the subjective evaluation fails, a second output is performed.

[0005] As a further improvement to this technical solution, multiple sensors for collecting NVH signals are set at equal intervals. Each sensor has the same timestamp for collecting NVH signals, and the distance of each sensor from the center coordinate of the acoustic package gradually increases, but the distance between two adjacent sensors is the same. The beneficial effect of the above-mentioned further solution is that, through the equidistant and orderly sensor layout, the collected NVH signals can be more systematically distributed in space. This makes it easier to more accurately capture the pattern of NVH signal variation with distance from the center of the acoustic package during subsequent NVH signal analysis. This allows for a more efficient and accurate evaluation of the acoustic package's control effect on electric drive noise, providing a more reliable basis for electric drive NVH optimization, helping to improve the overall vehicle NVH performance, and thus enhancing the vehicle's comfort and product competitiveness.

[0006] Based on the above technical solution, the present invention can also be improved as follows: sensing the NVH signals collected by the sensors at different coordinate points, setting equal angular intervals to determine the sampling time, performing discrete Fourier transform on the NVH signals within each sampling time, and extracting the maximum amplitude within the sampling time as the measured order. Using the center coordinates of the electric drive system as the origin, a selection direction is set, and the measured order of each NVH signal in the selected direction is retrieved. The rate of change of the corresponding measured order of two adjacent sensors is calculated. A rate of change threshold is set. If the rate of change is less than the rate of change threshold, it is determined that the rate of change has dropped sharply, and the electric drive system is wrapped with an acoustic package. At this time, the output warning signal includes a signal to add an acoustic package to the entire vehicle passenger compartment. Otherwise, it is determined that the electric drive system is not wrapped with an acoustic package. At this time, the output warning signal includes a signal to add an acoustic package.

[0007] The beneficial effect of the above-mentioned further solutions is that by using acoustic packages to block the propagation path of high-frequency noise from the electric drive, the overall NVH level of the vehicle is systematically optimized from both the electric drive body and the noise propagation path, thereby enhancing the competitiveness of the vehicle and better meeting consumers' increasing demand for comfort in new energy vehicles.

[0008] Based on the above technical solution, the present invention can be further improved as follows: the NVH signal of the time domain is converted into the NVH signal of the angle domain: from the initial time to the kth sampling time, the total angle of the output shaft rotation is k multiplied by the equal angle interval. Specifically, this is achieved by integrating the real-time rotation speed, with the integration interval from the initial time to the kth sampling time. During integration, the real-time rotation speed is divided by 30, and the integration result is equal to k multiplied by the equal angle interval. The equal angle resampling time is derived through the angular frequency, which is the real-time rotation speed divided by 30, ensuring that from the initial time to the kth sampling time, the rotation angle of the output shaft is k multiplied by the equal angle interval. The sampled NVH signals are accumulated. During accumulation, each NVH signal is multiplied by the corresponding complex exponent term to obtain multiple amplitude values ​​of the NVH signal at the k-th sampling time.

[0009] As a further improvement to this technical solution, the distance from each sensor to the vehicle center point is sensed, and different weighting coefficients are assigned to the NVH signals collected by each sensor based on different distances. Then, multiple amplitudes within the same sampling time are weighted and summed: the reciprocal of the distance from each sensor to the vehicle center point is calculated, the reciprocals of the distances from all sensors to the vehicle center point are added together, the weighting coefficient corresponding to the sensor is obtained by dividing the reciprocal of the distance from each sensor to the vehicle center point by the sum, the amplitude of the NVH signal collected by each sensor is multiplied by the corresponding weighting coefficient, and the products are added together to obtain the fused amplitude.

[0010] The beneficial effect of the above-mentioned further solution is that, by calculating the reciprocal of the distance from each sensor to the center point of the vehicle and summing the results to obtain the corresponding weighting coefficient, and by weighting and summing multiple amplitudes at the same sampling time, the signals from sensors at different locations can be more reasonably fused. This eliminates the influence of signal differences caused by the different spatial positions of the sensors, and makes the fused amplitude more accurately reflect the overall NVH situation of the vehicle. This provides a more reliable and representative signal basis for subsequent electric drive NVH optimization, thereby helping to carry out electric drive NVH optimization work more efficiently and accurately, improving the overall vehicle NVH performance, and enhancing vehicle comfort and product competitiveness.

[0011] Based on the above technical solution, the present invention can also be improved as follows: sensing the basic parameters of the electric drive system, calculating the core characteristic order of the motor and the characteristic order of each reduction ratio of the reducer; The characteristic order of a motor is the ratio of the time frequency of the electromagnetic force wave to the rotational frequency of the output shaft. The time frequency of the electromagnetic force wave is the product of the spatial order and the rotational frequency of the output shaft. The spatial order is determined by the number of stator slots, the number of rotor poles, and the harmonic order, and the spatial order satisfies a specific calculation relationship. The characteristic order of the motor is obtained by dividing the product of the spatial order and the frequency of the electromagnetic force wave by the rotational frequency of the output shaft. The characteristic order of a reducer is the product of the number of gear teeth and the rotational frequency of the output shaft.

[0012] As a further improvement to this technical solution, multiple motor characteristic orders are calculated by sensing different harmonic orders; multiple reducer characteristic orders are calculated by sensing the current output shaft speed and different reduction ratios.

[0013] As a further improvement to this technical solution, the weighted and fused NVH signal is received, and the corresponding comparison order and multiple characteristic orders of the motor and reducer are received; the absolute deviation between the comparison order and the multiple characteristic orders of the motor and reducer are calculated. Set an allowable error threshold; if the absolute deviation between the comparison order and a certain motor characteristic order is less than or equal to the allowable error threshold, then the comparison order is determined to belong to the motor order; if the absolute deviation between the comparison order and the reducer characteristic order is less than or equal to the allowable error threshold, then the comparison order is determined to belong to the reducer characteristic order.

[0014] The beneficial effects of the aforementioned further solutions are that they can accurately pinpoint the source of NVH problems in the electric drive system. If the problem originates from the motor, targeted NVH optimization can be performed on the motor, such as optimizing its electromagnetic design. If the problem originates from the reducer, optimization work can be carried out on aspects such as gear meshing in the reducer. This achieves a systematic improvement in the overall vehicle NVH level from the perspectives of the electric drive itself and the electric drive noise propagation path, effectively reducing electric drive-related noise, improving overall vehicle comfort, enhancing the vehicle's competitiveness in the market, and better meeting consumers' increasing demands for comfort in new energy vehicles.

[0015] Based on the above technical solution, the present invention can be further improved as follows: receiving comparison order. The matching results are used for multiple characteristic orders corresponding to the motor and reducer. If the matching result is the characteristic order of the motor, the theoretical frequency of the rotor order and the theoretical frequency of the stator order are calculated respectively.

[0016] As a further improvement to this technical solution, the receiving comparison order frequency is... Set tolerance threshold Calculate the matching interval If the rotor's theoretical order frequency is within the matching range If the motor order is within the range, then the rotor order is determined; if the stator order theoretical frequency is within the matching range... If the motor order is determined to be the stator order, then an optimization signal is output based on the determination result. When comparing the characteristic order of the reducer, the corresponding comparison order of the reducer characteristic order should be retrieved. The reduction ratio is used to determine the characteristic order of the reducer, and then an optimized signal is output.

[0017] The beneficial effect of the above-mentioned further solution is that by setting a tolerance threshold to calculate the matching interval, and by judging whether the theoretical frequencies of the rotor and stator orders are within the matching interval, the motor order type can be accurately determined. If the compared order belongs to the characteristic order of the reducer, the corresponding reduction ratio is selected to determine the characteristic order of the reducer, and then an optimization signal is output. In this way, the NVH problem in the electric drive system can be accurately located as originating from the rotor, stator, or reducer of the motor, thereby outputting an optimization signal in a targeted manner.

[0018] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the NVH optimization of the electric drive body of the present invention; Figure 2 This is a schematic diagram of the external NVH optimization of the electric drive in this invention. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] refer to Figure 1 and Figure 2As shown, a method for optimizing the NVH (noise, vibration, and harshness) of electric drive systems in new energy vehicles includes the following steps: S1. Multiple sensors are set at equal intervals to collect NVH signals (NVH signals are noise, vibration, and harshness signals, which reflect the comprehensive signals of noise, vibration, and related sound quality characteristics of a vehicle during operation). Each sensor collects NVH signals at the same timestamp, and the distance of each sensor from the center coordinate of the acoustic package gradually increases, but the distance between two adjacent sensors is the same, ensuring that the NVH signals collected by sensors at different coordinates are comparable in time and space. It senses NVH signals collected by sensors at different coordinate points, and then sets equal angular intervals. Determine the first Each sampling time Then for each sampling time The NVH signal within is subjected to Discrete Fourier Transform to extract the sampling time. The maximum amplitude within is the measured order. ; Using the center coordinates of the electric drive system as the origin, set the selection direction and retrieve the measured order of each NVH signal in the selected direction. ,in , The number of sensors; calculate the measured order corresponding to two adjacent sensors. rate of change in For the first The and the first The spacing between the sensors; Because acoustic packages have sound absorption and sound insulation properties, when an electric drive system is encased in an acoustic package, the package absorbs and blocks the noise and vibration generated by the electric drive, thus improving the measured order of NVH signals during propagation. The noise gradually decreases, and because the distance between the sensor and the center of the acoustic package varies at different coordinate points, this distance difference causes the rate of change of the NVH signal to exhibit a specific pattern. Therefore, a rate of change threshold is set. If a rate of change exists < Rate of change threshold Then determine the rate of change. If the electric drive system is suddenly depressurized, it will be equipped with an acoustic package, and an alert signal will be output indicating that the acoustic package covering the entire passenger compartment has been increased to effectively reduce the sound pressure level of electric drive noise inside the vehicle. Conversely, if the electric drive system is not equipped with an acoustic package, an alert signal will be output indicating that the acoustic package has been increased to block some of the high-frequency noise propagation paths of the electric drive system.

[0022] Sampling time extracted from S1 The working principle of the internal amplitude is as follows: To eliminate the influence of rotational speed fluctuations and ensure that the sampling time strictly corresponds to the rotation angle, the NVH signal of the time domain is converted into the NVH signal of the angle domain by analyzing the equal angle resampling time. The specific working principle is: setting equal angle intervals. Determine the first Each sampling time So that from the initial moment to The total rotation angle of the output shaft is The specific expression is: ,in The intervals are equal in angle. This is a function of the motor's real-time speed. For the first Each sampling time; the formula for calculating the equal-angle resampling time is based on angular frequency. Derivation, ensuring from the initial moment The angle turned is equal to ; For each sampling time Perform Discrete Fourier Transform on the NVH signal within: ,in The number of sampling points. The imaginary unit is used to obtain the NVH signal. Each sampling time Multiple amplitude values.

[0023] S2, Sensing the sampling times of NVH signals collected by multiple sensors Multiple amplitude values ​​are obtained, a vehicle center point is defined, and the multiple amplitude values ​​are weighted and summed based on the distance between the vehicle center point and each sensor. ,in These are weighting coefficients. For the first The distance from each sensor to the center point of the vehicle Used for all Sum the reciprocals of the distances from each sensor to the center of the vehicle. To sum the index variables, this invention considers that during actual vehicle operation, sensors at different coordinates are affected by various factors such as vehicle body structure, acoustic environment, and vibration propagation path, resulting in differences in the "representativeness" of NVH signals collected by sensors at different coordinates to the overall NVH characteristics of the vehicle. The vehicle center point is a key reference point for measuring NVH characteristics from the perspective of the entire vehicle. The closer the sensor is to the vehicle center point, the more directly and comprehensively the vibration and noise signals at that sensor location can reflect the overall NVH state of the vehicle. Therefore, when comprehensively evaluating the overall NVH characteristics of the vehicle, the corresponding NVH signal has a higher importance. Thus, when weighting and summing multiple amplitudes, the closer the distance between the vehicle center point and each sensor, the higher the weighting coefficient. The larger; If the electric drive system is encased in an acoustic enclosure, the enclosure will absorb and insulate noise and vibration (NVH) signals to a certain extent, resulting in a more uniform energy distribution of the NVH signals. In this case, the sampling time corresponding to the weighted and fused NVH signal is extracted again. Multiple amplitudes within The mean amplitude is calculated as the comparison order. This allows for the integration of NVH signals from multiple moments, avoiding errors in subsequent order judgments caused by occasional fluctuations at individual moments. If the electric drive system is not encased in an acoustic enclosure, the NVH signal energy generated by the rotating components of the electric drive (such as motors, gears, etc.) is more concentrated, often exhibiting significant peaks at certain specific moments. Therefore, the weighted fused NVH signal corresponds to the sampling moment... The maximum amplitude within the range is the contrast order corresponding to the NVH signal. It can directly reflect the strongest order characteristics of vibration or noise of electrically driven rotating parts.

[0024] S3, Sensing the basic parameters of the electric drive system (the basic parameters of the electric drive system include the number of motor poles) Number of stator slots Reduction ratio of each gear Number of gear teeth Harmonic number ( The output shaft speed is collected by a sensor. (NVH signals) to calculate the order of the core characteristics of the motor. and the characteristic order of each reduction ratio of the reducer ; Motor characteristic order The time frequency of electromagnetic force waves ( For spatial order, spatial order Based on the number of stator slots Number of rotor poles Harmonic frequency Decision, satisfaction ) and output shaft speed frequency ( The ratio of the output shaft speed (acquired by the sensor): The harmonic order By adjusting the control parameters of the frequency converter (modulation method (pulse width modulation, PWM, etc.)), the harmonic content in the motor output current is changed, thus altering the signal. According to the above formula, the spatial order Different harmonic orders can be derived. This will lead to spatial order Different, spatial order Different explanations indicate that the distribution of electromagnetic force on the stator circumference varies, resulting in different force patterns on components such as the stator core. This, in turn, affects the motor's vibration and noise characteristics, and subsequently, multiple harmonic orders in the fundamental parameters of the electric drive system are analyzed. Substituting into the above calculation formula, we obtain multiple characteristic orders of the motor. ; Reducer characteristic order Number of teeth of the gear With output shaft speed frequency ( The output shaft speed. The reduction ratio, The product of the input shaft speed and the input shaft rotation speed. Sensing the current output shaft speed Substitute different reduction ratios Calculate the characteristic orders of multiple reducers .

[0025] S4. Comparison order of the received weighted and fused NVH signal Motors and reducers correspond to multiple characteristic orders. , ; Calculate the contrast order Multiple characteristic orders correspond to motors and reducers. , absolute deviation ; Set an allowable error threshold; if comparing order With a certain characteristic order of a motor absolute deviation If the error is less than or equal to the allowable error threshold, then the comparison order is determined. Belongs to the motor order If comparing orders With the characteristic order of the reducer absolute deviation If the error is less than or equal to the allowable error threshold, then the comparison order is determined. Belongs to the characteristic order of the reducer ; Received contrast order Multiple characteristic orders correspond to motors and reducers. , The matching result, if the matching result is the motor characteristic order Then, calculate the theoretical frequencies of the rotor order respectively. Stator order theoretical frequency ; Receive contrast order frequency (in For order, (For rotational speed), set tolerance threshold. Calculate the matching interval If the rotor order theoretical frequency In the matching range Inside, the motor order To determine the rotor order If the stator order theoretical frequency In the matching range Inside, the motor order To determine the stator order ; For example: if the number of stator slots Number of rotor poles Sensors collect and output shaft speed Harmonic number ; Receive comparison order frequency Tolerance threshold Then the matching interval ; Rotor order theoretical frequency Stator order theoretical frequency When the value is positive, the theoretical frequency of the stator order is [value]; when the value is negative, the theoretical frequency of the stator order is [value]. ; In summary, due to the stator order theoretical frequency In the matching range Therefore, the motor order is determined. To determine the stator order ; Determine the motor order Corresponding order (stator order) Rotor order After that, analyze and output the optimized signal (motor order). Corresponding stator order At that time, the output optimization signal includes information such as optimizing the stator winding arrangement and improving the stator core tightness; motor order. Corresponding rotor order (At the same time, the output optimization signal includes information such as adjusting rotor dynamic balance and optimizing rotor structural stiffness). If comparing the order Characteristic order of the reducer At that time, the characteristic order of the reducer is selected. Corresponding contrast order Reduction ratio Based on the reduction ratio The characteristic order of the reducer is determined, and then an optimization signal is output. This optimized signal includes information such as the reducer's characteristic order, improvements in gear accuracy, optimization of gear tooth profile, and enhancement of gear lubrication; for example, the reduction ratio. The characteristic order of the reducer This is the first deceleration order; such as the deceleration ratio. The characteristic order of the reducer This is a two-stage reduction gear. If it is a single-stage reduction gear, then the single-stage reduction gear is optimized.

[0026] After outputting reminder and optimization signals, S5 performs subjective evaluations. Relying on professional NVH evaluation personnel (or teams), the subjective perception of noise and vibration by humans is used, combined with industry or company internal NVH subjective evaluation standards / specifications to determine whether the subjective evaluation is passed. If the subjective evaluation is passed, NVH optimization is completed; if the subjective evaluation is not passed, a second output is performed.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new energy vehicle electric drive NVH optimization method, characterized in that, The method comprises the following steps: setting a plurality of sensors for collecting NVH signals, extracting a plurality of amplitudes corresponding to the collection time in each NVH signal, calling the maximum amplitude as the measured order, judging whether the electric drive system is wrapped in an acoustic package, and then outputting a prompt signal; sensing a plurality of amplitudes corresponding to the sampling time of the NVH signals collected by the plurality of sensors, setting a vehicle center point, and fusing the plurality of amplitudes by weighted summation according to the distance between the vehicle center point and each sensor; when the electric drive system is wrapped in an acoustic package, calculating the average of the plurality of amplitudes as the comparison order; when the electric drive system is not wrapped in an acoustic package, calling the maximum amplitude in the weighted summation of the plurality of amplitudes as the comparison order; calculating the motor core characteristic order and the reducer characteristic order of each reduction ratio respectively; judging the characteristic order to which the comparison order belongs; if the comparison order belongs to the motor core characteristic order, then judging the stator order and the rotor order again, and outputting an optimization signal according to the judgment result; if the comparison order belongs to the reducer characteristic order, then calling the corresponding reduction ratio and outputting the corresponding optimization signal; after outputting the prompt signal and the optimization signal, performing subjective evaluation, and judging whether the subjective evaluation is passed; if the subjective evaluation is passed, completing the NVH optimization; if the subjective evaluation is not passed, then performing secondary output.

2. The new energy vehicle electric drive NVH optimization method according to claim 1, characterized in that: The plurality of sensors for collecting NVH signals are equidistantly set, the time stamp of the NVH signal collected by each sensor is the same, and the distance between each sensor and the center coordinate of the acoustic package gradually increases, but the distance between two adjacent sensors is the same.

3. The new energy vehicle electric drive NVH optimization method according to claim 2, characterized in that: Sensing the NVH signals collected by the sensors at different coordinate points, setting equiangular interval to determine the sampling time, performing discrete Fourier transform on the NVH signals in each sampling time, and extracting the maximum amplitude in the sampling time as the measured order; Taking the center coordinate of the electric drive system as the origin, setting a selection direction, and calling the measured order of each NVH signal in the selection direction; calculating the change rate of the measured orders corresponding to the adjacent two sensors; setting a change rate threshold, if there is a change rate < the change rate threshold, then judging that the change rate drops sharply, and the electric drive system is wrapped in an acoustic package, at this time the output prompt signal includes a signal of adding an acoustic package to the vehicle passenger compartment; otherwise, it is judged that the electric drive system is not wrapped in an acoustic package, at this time the output prompt signal includes a signal of adding an acoustic package.

4. The new energy vehicle electric drive NVH optimization method of claim 3, wherein: The NVH signal in the time domain is converted into the NVH signal in the angle domain: from the initial time to the kth sampling time, the total angle of the output shaft rotation is k times the equiangular interval, specifically by integrating the real-time speed, the integration interval is from the initial time to the kth sampling time, the integration time is the real-time speed divided by thirty, and the integration result is equal to k times the equiangular interval; the equiangular resampling time is derived by the angular frequency, the angular frequency is the real-time speed divided by thirty, and it is ensured that from the initial time to the kth sampling time, the output shaft rotation angle is k times the equiangular interval; The sampled NVH signals are accumulated, and each NVH signal is multiplied by the corresponding complex exponential term during accumulation to obtain a plurality of amplitudes of the NVH signal at the kth sampling time.

5. The new energy vehicle electric drive NVH optimization method according to claim 4, characterized in that: The distance from each sensor to the center point of the vehicle is perceived, different weighting coefficients are assigned to the NVH signals collected by each sensor according to different distances, and then the weighted sum of multiple amplitudes at the same sampling time is calculated: the reciprocal of the distance from each sensor to the center point of the vehicle is calculated, the reciprocals of the distances from all sensors to the center point of the vehicle are added, the reciprocal of the distance from each sensor to the center point of the vehicle is divided by the sum to obtain the corresponding weighting coefficient of the sensor, the amplitude of the NVH signal collected by each sensor is multiplied by the corresponding weighting coefficient, the products are added, and the fused amplitude is obtained.

6. The new energy vehicle electric drive NVH optimization method of claim 1, wherein: The basic parameters of the electric drive system are perceived, and the core characteristic order of the motor and the characteristic order of each reduction ratio of the reducer are calculated. The motor characteristic order is the ratio of the time frequency of the electromagnetic force wave to the output shaft speed frequency, the time frequency of the electromagnetic force wave is the product of the spatial order and the output shaft rotation frequency, the spatial order is determined by the number of stator slots, the number of rotor poles and the harmonic number, and the spatial order satisfies a specific calculation relationship; the product of the spatial order and the electromagnetic force wave frequency is divided by the output shaft rotation frequency to obtain the motor characteristic order. The reducer characteristic order is the product of the gear tooth number and the output shaft rotation frequency.

7. The new energy vehicle electric drive NVH optimization method according to claim 6, characterized in that: Multiple motor characteristic orders are calculated by perceiving different harmonic numbers; multiple reducer characteristic orders are calculated by perceiving the current output shaft speed and different reduction ratios.

8. The new energy vehicle electric drive NVH optimization method according to claim 7, characterized in that: The corresponding comparison order of the weighted and fused NVH signal and the multiple characteristic orders of the motor and the reducer are received; the absolute deviation of the comparison order and the multiple characteristic orders of the motor and the reducer is calculated. An allowable error threshold is set; if the absolute deviation of the comparison order and a certain motor characteristic order is less than or equal to the allowable error threshold, it is judged that the comparison order belongs to the motor order; if the absolute deviation of the comparison order and the reducer characteristic order is less than or equal to the allowable error threshold, it is judged that the comparison order belongs to the reducer characteristic order. 9.The new energy vehicle electric drive NVH optimization method of claim 8, wherein: Receiving a contrast order The matching results of the multiple characteristic orders corresponding to the motor and the reducer are obtained. If the matching result is the motor characteristic order, the rotor order theoretical frequency and the stator order theoretical frequency are calculated respectively.

10. The new energy vehicle electric drive NVH optimization method of claim 9, wherein: Receiving a contrast order frequency , setting a tolerance threshold , calculating a matching interval , if the rotor order theoretical frequency is in the matching interval , the motor order is determined as the rotor order; if the stator order theoretical frequency is in the matching interval , the motor order is determined as the stator order, and then output an optimization signal according to the judgment result; If the comparison order belongs to the reducer feature order, the reducer feature order corresponding to the comparison order is called The reduction ratio is determined according to the reducer feature order, and then the optimization signal is output.

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