A powertrain collision detection system and method with frequency filtering

Abstract

This invention discloses a powertrain collision detection system with frequency filtering. It includes a data setting module for adjusting the motor speed and torque to set parameters; an acceleration sensor for collecting vibration signals from the powertrain at various time points; and a kurtosis value calculation module for low-pass filtering the peak amplitude of the vibration signals and calculating the kurtosis value using the low-pass filtered peak amplitude. This invention can eliminate and remove high-frequency energy, solving the problems of high false interception rate and high missed interception rate in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of powertrain testing technology, specifically to a powertrain collision detection system and method with frequency filtering. Background Technology

[0002] With the global surge in electric vehicle adoption, component integration has become an inevitable trend. New energy vehicles, especially electric vehicles, are generally quieter than traditional combustion engine vehicles due to the working principle of their electric motors. Therefore, NVH (an abbreviation for Noise, Vibration, and Harshness) testing has become an important indicator of vehicle performance and user experience.

[0003] The NVH problems of new energy vehicles mainly come from the impact of shaft teeth and vibration signal burrs in the powertrain. These problems are generally intercepted by visual inspection and NVH detection. Among them, the detection method is to use the Kurtosis index (used to assess the number and density of impact damage) for evaluation. However, the existing index identification still has the problems of high false interception rate of vibration signal burrs and missed interception.

[0004] Therefore, inventing a powertrain collision detection system that uses frequency filtering to remove false burrs and eliminate high-frequency energy in order to reduce false interception rate and missed interception rate is an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a powertrain collision detection system and method with frequency filtering. This invention can remove false spikes in the powertrain vibration detection signal, eliminate high-frequency energy in the powertrain vibration detection signal, and reduce the technical problems of false interception rate and missed interception rate of vibration signal spikes.

[0006] To achieve this objective, the present invention provides a powertrain collision detection system with frequency filtering, comprising:

[0007] The data setting module is used to adjust the motor speed and motor torque to the set motor speed and motor torque;

[0008] Accelerometers are used to collect vibration signals of the powertrain at various time points when the motor is running at a set motor speed and motor torque.

[0009] The kurtosis numerical calculation module is used to perform low-pass filtering on the peak amplitude of the vibration signal in each time period, and to calculate the kurtosis value of each time period using the peak amplitude of the vibration signal in each time period after low-pass filtering.

[0010] Preferably, the motor speed setting range is 2000rpm to 5000rpm.

[0011] Preferably, the motor torque setting range is 5Nm to 20Nm.

[0012] Preferably, the peak value calculation module performs low-pass filtering on the peak amplitude of the vibration signal using TasAlyser software to filter out frequencies above 2000Hz in the vibration signal.

[0013] Preferably, the Kurtosis value is a characteristic number that characterizes the peak value of the probability density distribution curve at the average value. The larger the Kurtosis value, the larger the variance of the vibration signal. The Kurtosis value is proportional to the variance of the vibration signal generated by the powertrain collision interference. The Kurtosis value is used to characterize the collision situation of the powertrain.

[0014] The beneficial effects of this invention are:

[0015] This invention provides a powertrain impact detection system with frequency filtering. By performing low-pass filtering on the peak amplitude of the vibration signal, frequencies above 2000Hz in the vibration signal are filtered out, and then the Kurtosis value is calculated.

[0016] High-frequency energy may contain noise or interference signals, which may be incorrectly identified as target signals by the system, leading to an increased false interception rate. As the impact of integrated drive system NVH on overall vehicle performance increases, the vibration and noise performance of the drive system directly affects the NVH performance of electric vehicles. By reducing these high-frequency interferences, the detection system can more accurately identify collision events, thereby reducing the false interception and missed interception rates. This solution achieves the elimination of high-frequency energy through filtering, solving the problems of high false interception and missed interception rates in existing technologies. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention;

[0018] Figure 2 This is a flowchart illustrating the implementation of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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 a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0021] Example 1

[0022] A powertrain collision detection system with frequency filtering, such as Figure 1 As shown, it includes:

[0023] The data setting module is used to adjust the motor speed and motor torque to the set motor speed and motor torque;

[0024] Accelerometers are used to collect vibration signals of the powertrain at various time points when the motor is running at a set motor speed and motor torque.

[0025] The kurtosis numerical calculation module is used to perform low-pass filtering on the peak amplitude of the vibration signal in each time period, and to calculate the kurtosis value of each time period using the peak amplitude of the vibration signal in each time period after low-pass filtering.

[0026] In the above technical solution, the motor speed setting range is 2000rpm~5000rpm; the motor torque setting range is 5Nm~20Nm. The vibration characteristics of the motor are closely related to its speed and torque. Under the above speed and torque, the vibration signal generated by the motor has specific frequency and amplitude characteristics, thus having relatively stable frequency and amplitude characteristics. It can also ensure that each test is carried out under the same conditions, thereby improving the accuracy and comparability of the test results. The signal collected at this time can more realistically reflect the operating status of the powertrain and avoid signal interference and errors caused by changes in speed and torque. If the motor speed and torque are unstable or outside the set range, the vibration signal of the powertrain will be interfered with, resulting in inaccurate data collected by the acceleration sensor. This will directly affect the calculation of peak values ​​and the accuracy of impact detection.

[0027] In actual operation, the speed and torque of a motor may change due to various external factors, such as load changes and power supply voltage fluctuations. These factors may cause vibration signal fluctuations and interference, thus affecting the accuracy of fault detection. By collecting signals at the set motor speed and torque, these changes can be captured more easily, minimizing the interference of these external factors. By monitoring significant changes in vibration signals in real time, fault signs can be detected earlier, potential fault trends can be identified in a timely manner, providing strong support for maintenance and repair, and improving the sensitivity of fault detection.

[0028] In the above technical solutions, the design of low-pass filters is usually targeted at a specific frequency range. Under the set motor speed and torque, the vibration signal of the powertrain may be concentrated in a specific frequency range, which makes the low-pass filter more effective in removing high-frequency noise and retaining useful vibration information.

[0029] In the above technical solution, the kurtosis numerical calculation module performs low-pass filtering on the peak amplitude of the vibration signal, filtering out frequencies above 2000Hz. The vibration signal of the powertrain usually contains multiple frequency components. Among them, the low-frequency components are often closely related to the vibration state of mechanical parts, while the high-frequency components may come from various interference sources. Therefore, removing high-frequency noise through low-pass filtering can more accurately reflect the vibration state of mechanical parts, effectively remove these high-frequency noises, purify the vibration signal, and make the peak amplitude more accurate. Under the influence of high-frequency noise, the amplitude distribution of the signal may change, resulting in inaccurate kurtosis values. Therefore, before calculating the kurtosis values, it is necessary to perform low-pass filtering on the peak amplitude to eliminate the influence of high-frequency noise.

[0030] In the above technical solution, the specific calculation formula for calculating the kurtosis value using the peak amplitude of the vibration signal after low-pass filtering in the kurtosis value calculation module is as follows:

[0031]

[0032] Wherein, Kurtosis is the peak value of a certain time period, X is the peak amplitude of the vibration signal after low-pass filtering for a certain time period, μ is the average value of the peak amplitude of the vibration signal after low-pass filtering for a certain time period, σ is the standard deviation of the peak amplitude of the vibration signal after low-pass filtering for a certain time period, and E represents the expected value of the peak amplitude of the vibration signal after low-pass filtering for a certain time period. The expected value of the peak amplitude is used to describe the average level of the peak amplitude in the vibration waveform, and the standard deviation of the peak amplitude is used to measure the degree of signal dispersion, which reflects the magnitude of the vibration signal fluctuation.

[0033] In the above technical solution, by adding a low-pass filter to the Kurtosis calculation method, the unqualified powertrain vibration signal is distinguished from the qualified powertrain vibration signal, and precise interception is achieved.

[0034] In the above technical solution, by adding a low-pass filter to the Kurtosis calculation method, the unqualified powertrain vibration signal is distinguished from the qualified powertrain vibration signal, and precise interception is achieved.

[0035] In the above technical solution, the Kurtosis value is a characteristic number that characterizes the peak value of the probability density distribution curve at the average value, reflecting the sharpness of the peak of the probability density distribution curve. The kurtosis coefficient of the sample is a statistical quantity compared with the normal distribution. The larger the Kurtosis value, the larger the variance of the vibration signal. The Kurtosis value is proportional to the variance of the vibration signal generated by the powertrain collision interference. The Kurtosis value is used to characterize the powertrain collision situation. In this embodiment, a comparison table of Kurtosis values ​​and powertrain collision degree is obtained through repeated experiments. The corresponding powertrain collision degree is determined based on the current Kurtosis value and the comparison table.

[0036] Example 2

[0037] A powertrain impact detection method with frequency filtering, such as Figure 2 As shown, the vibration signal of the powertrain of the tested object is acquired by the signal acquisition card in the NVH sensor. By performing low-pass filtering on the peak amplitude of the vibration signal, the frequencies above 2000Hz in the vibration signal are filtered out, and then the peak value is calculated.

[0038] A specific analysis method for powertrain collision detection with frequency filtering includes the following steps:

[0039] Adjust the motor speed and motor torque to the set motor speed and motor torque;

[0040] Vibration signals of the powertrain are collected at various time points when the motor is running at the set motor speed and motor torque.

[0041] The peak amplitude of the vibration signal in each time period is low-pass filtered, and the peak value of each time period is calculated using the peak amplitude of the vibration signal in each time period after low-pass filtering.

[0042] Example 3

[0043] A computer program product includes a computer program that, when executed by a processor, implements the steps of the method described in Embodiment 2.

[0044] Example 4

[0045] An electronic device includes a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the steps of the method as described in Embodiment 2.

[0046] Example 5

[0047] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method as described in Embodiment 2.

[0048] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0049] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A system that specifies functions in one or more boxes.

[0050] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including an instruction set implemented in a process. Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0051] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0052] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A powertrain collision detection system with frequency filtering, characterized in that, It includes: The data setting module is used to adjust the motor speed and motor torque to the set motor speed and motor torque; Accelerometers are used to collect vibration signals of the powertrain at various time points when the motor is running at a set motor speed and motor torque. The kurtosis numerical calculation module is used to perform low-pass filtering on the peak amplitude of the vibration signal in each time period, and to calculate the kurtosis value for each time period using the peak amplitude of the vibration signal in each time period after low-pass filtering. The specific calculation method is as follows: in, This represents the peak value over a certain period of time. This represents the peak amplitude of the vibration signal during a certain period after low-pass filtering. This represents the average value of the peak amplitude of the vibration signal over a certain period after low-pass filtering. This represents the standard deviation of the peak amplitude of the vibration signal after low-pass filtering over a certain period of time. This represents the expected value of the peak amplitude of the vibration signal after low-pass filtering for a certain period of time. The kurtosis value is a characteristic number that characterizes the peak value of the probability density distribution curve at the average value. The larger the kurtosis value, the larger the variance of the vibration signal. The kurtosis value is proportional to the variance of the vibration signal generated by the powertrain collision interference. The kurtosis value is used to characterize the collision situation of the powertrain.

2. The powertrain collision detection system with frequency filtering according to claim 1, characterized in that: The set motor speed range is 2000rpm~5000rpm.

3. The powertrain collision detection system with frequency filtering according to claim 1, characterized in that: The set motor torque range is 5Nm~20Nm.

4. The powertrain collision detection system with frequency filtering according to claim 1, characterized in that: The kurtosis numerical calculation module performs low-pass filtering on the peak amplitude of the vibration signal at each time period, filtering out frequencies above 2000Hz in the peak amplitude of the vibration signal.

5. A powertrain collision detection method with frequency filtering according to claim 1, characterized in that, It includes the following steps: Adjust the motor speed and motor torque to the set motor speed and motor torque; Vibration signals of the powertrain are collected at various time points when the motor is running at the set motor speed and motor torque. The peak amplitude of the vibration signal in each time period is low-pass filtered, and the peak value of each time period is calculated using the peak amplitude of the vibration signal in each time period after low-pass filtering.

6. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method described in claim 5.

7. An electronic device, characterized in that, include: A memory and a processor are communicatively connected, the memory storing computer instructions, and the processor executing the computer instructions to perform the steps of the method as described in claim 5.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it implements the steps of the method as described in claim 5.

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