An electric vehicle low-speed alarm control system, control method and medium

Abstract

The application discloses a low-speed alarm control system, a control method and a medium for an electric vehicle, and relates to the technical field of vehicles.The control system comprises a data acquisition unit configured to acquire vehicle speed information, vehicle surrounding environment information and vehicle surrounding sound information; an information processing module configured to convert the vehicle surrounding sound information into a frequency-sound pressure curve when it is determined that the low-speed alarm needs to play a prompt sound; determine whether the frequency peak is in a preset frequency interval and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any frequency of the preset prompt sound, and calculate a characteristic frequency band; obtain a characteristic frequency band range according to the characteristic frequency band and the frequency peak; and an audio control module configured to adjust and play the preset prompt sound when the frequency of the preset prompt sound is in the characteristic frequency band range. The sound pressure level and the frequency of the prompt sound are adjusted in real time according to different situations, the masking effect of the environmental noise around the vehicle is avoided, and the safety risk is effectively reduced.

Description

Technical Field

[0001] This invention generally relates to the field of vehicle technology, and specifically to a low-speed alarm control system, control method, and medium for electric vehicles. Background Technology

[0002] As electric vehicles are included in the development strategies of many countries around the world, their technological development is accelerating and their adoption rate is increasing. Electric vehicles use clean energy, reducing environmental pollution. However, because electric vehicles are very quiet when traveling at low speeds, pedestrians, especially those with hearing impairments, may have difficulty noticing their approach, posing a significant safety hazard.

[0003] To address the pedestrian safety issues caused by the low noise levels of electric vehicles, low-speed warning sound systems were developed. Meanwhile, the national standard GB / T 37153-2018, "Low-Speed ​​Warning Sounds for Electric Vehicles," was promulgated, specifying noise limits and testing methods for vehicles equipped with low-speed warning sound systems. This standard officially came into effect on July 1, 2019.

[0004] CN103108777A discloses a system and method for generating external warning sounds for vehicles. It discloses adjusting the volume to make the generated warning sound audible to ambient noise; the warning sound is divided into multiple frequency bands, and the gain in each frequency band is adjusted based on the ambient noise level in each band. This patent emphasizes adjusting the volume and narrow-band gain to highlight the warning sound; however, this adjustment scheme is relatively simple and does not disclose a fusion control method using multiple strategies, making it difficult to achieve the effect of reducing ambient sound masking in practical implementation.

[0005] In view of the shortcomings of the above-mentioned technologies, this invention is proposed. Summary of the Invention

[0006] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a control system, control method and medium for electric vehicle low-speed alarm that is highly applicable, whose prompt sound is more easily recognized by pedestrians, reduces safety risks, saves energy and reduces environmental noise pollution.

[0007] In a first aspect, the present invention provides a low-speed alarm control system for electric vehicles, comprising: The data acquisition unit is configured to collect vehicle speed information, vehicle surrounding environment information, and vehicle surrounding sound information. An information processing module is communicatively connected to the data acquisition unit. The information processing module is configured to acquire ambient sound information of the vehicle when it is determined that the low-speed alarm needs to play a prompt sound. Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve. Obtain the frequency peak value and the sound pressure level corresponding to the frequency peak value in the frequency-sound pressure curve; When it is determined that the frequency peak is within a preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset prompt tone frequency, the characteristic frequency band corresponding to the frequency peak is calculated. The characteristic frequency band range is obtained based on the characteristic frequency band and the frequency peak value; An audio control module is communicatively connected to the information processing module. The audio control module is configured to adjust and play the preset prompt tone using a first method, a second method, or a third method when the frequency of the preset prompt tone is within a characteristic frequency band.

[0008] According to the technical solution provided by the present invention, the data acquisition unit includes: The CAN communication module is configured to collect vehicle speed information. Vehicle-mounted camera module, configured to collect information about the environment surrounding the vehicle; The sound acquisition module is configured to collect sound information around the vehicle.

[0009] According to the technical solution provided by the present invention, it further includes: a voltage control module, wherein the voltage control module is communicatively connected to the audio control module, and is configured to adjust the voltage of the low-speed alarm according to the adjusted preset prompt tone, thereby changing the current of the low-speed alarm to change the volume of the adjusted preset prompt tone.

[0010] According to the technical solution provided by the present invention, it further includes: a direction adjustment module, which is communicatively connected to the audio control module and configured to adjust the playback direction of the preset prompt tone according to the surrounding environment information of the vehicle.

[0011] Secondly, the present invention provides a control method for a low-speed alarm in an electric vehicle, based on the aforementioned control system for a low-speed alarm in an electric vehicle, the control method comprising the following steps: When it is determined that the low-speed alarm needs to play a prompt tone, obtain the sound information around the vehicle; Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve. Obtain the frequency peak value and the sound pressure level corresponding to the frequency peak value in the frequency-sound pressure curve; When it is determined that the frequency peak is within a preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset prompt tone frequency, the characteristic frequency band corresponding to the frequency peak is calculated. The characteristic frequency band range is obtained based on the characteristic frequency band and the frequency peak value; When it is determined that the frequency of the preset prompt tone is within the characteristic frequency band, the preset prompt tone is adjusted and played using the first method, the second method, or the third method. The first method includes the following steps: When the sound pressure level corresponding to the frequency peak is greater than a first threshold, or when the frequency peak is equal to the frequency of the preset prompt tone, the low-speed alarm generates a sound that is opposite in phase and has the same frequency as the frequency peak; the first threshold is a set minimum value of external noise passing by the vehicle. The second method includes the following steps: When it is determined that the frequency of the preset prompt tone is within a first preset range, the sound pressure level of the preset prompt tone is increased to be consistent with the sound pressure level corresponding to the peak frequency. The third method includes the following steps: When it is determined that the frequency of the preset prompt tone is within the second preset range, the sound pressure level of the preset prompt tone is increased, and the frequency of the preset prompt tone is decreased or increased; The absolute value of the difference between the upper limit of the first preset range and the upper limit of the second preset range is equal to twice the feature frequency band; and the absolute value of the difference between the lower limit of the first preset range and the lower limit of the second preset range is equal to twice the feature frequency band.

[0012] According to the technical solution provided by the present invention, determining that a low-speed alarm needs to play a prompt sound specifically includes the following steps: Obtain vehicle speed information; When the vehicle speed information is determined to meet the first triggering condition, the vehicle safety distance is calculated based on the vehicle speed information. Obtain information about the vehicle's surrounding environment within the vehicle's safe distance range; When the environmental information surrounding the vehicle is determined to meet the second triggering condition, the low-speed alarm is required to play a prompt sound.

[0013] According to the technical solution provided by the present invention, the safe distance between vehicles is calculated according to the following formula: ; Where s is the safe distance between vehicles, v is the vehicle speed, and a is the braking acceleration.

[0014] According to the technical solution provided by the present invention, the first triggering condition is that the vehicle's forward speed is within the range of 0-20 km / h or the vehicle is in reverse gear; the second triggering condition is that an object requiring a warning sound is identified in the environmental information surrounding the vehicle.

[0015] According to the technical solution provided by the present invention, obtaining the frequency peak value in the frequency-sound pressure curve specifically includes the following steps: The frequency peak value in the frequency-sound pressure curve is obtained by using the golden section algorithm for fine search.

[0016] Thirdly, the present invention provides a storage medium, which is a type of computer-readable storage medium, having a computer program stored thereon, wherein when the computer program is executed by a processor, it implements the electric vehicle low-speed alarm control method described above.

[0017] In summary, this invention discloses a specific structure for a low-speed alarm control system for electric vehicles. This invention utilizes a data acquisition unit to collect vehicle speed information, surrounding environment information, and surrounding sound information; it sets up an information processing module communicatively connected to the data acquisition unit, configured to acquire surrounding sound information when it determines that the low-speed alarm needs to play a warning tone; based on the FFT algorithm, it converts the surrounding sound information into a frequency-sound pressure curve; it acquires the frequency peak and the corresponding sound pressure level in the frequency-sound pressure curve; when it determines that the frequency peak is within a preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset warning tone frequency, it calculates the characteristic frequency band corresponding to the frequency peak; based on the characteristic frequency band and the frequency peak, it obtains the characteristic frequency band range; it also sets up an audio control module communicatively connected to the information processing module, configured to adjust and play the preset warning tone using a first method, a second method, or a third method when it determines that the frequency of the preset warning tone is within the characteristic frequency band range.

[0018] Compared to traditional solutions that only adjust the warning tone, this invention takes into account the uncertainty and diversity of ambient sounds during actual vehicle operation. Through the cooperation of a data acquisition unit, an information processing module, and an audio control module, it achieves three adjustment methods. By comparing the initial warning tone of the low-speed alarm with the frequency peaks of sounds around the vehicle, it determines which adjustment method to select for the final warning tone played by the low-speed alarm. Under the premise of complying with regulations, it effectively avoids the masking effect of ambient noise around the vehicle, effectively reduces safety risks, and has greater applicability. Attached Figure Description

[0019] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a flowchart illustrating the control method for a low-speed alarm in an electric vehicle.

[0020] Figure 2 A flowchart illustrating the process of determining when a low-speed alarm needs to play a prompt sound.

[0021] Figure 3This is a schematic diagram of the control system for a low-speed alarm in an electric vehicle.

[0022] The following are labeled in the diagram: 1. Data acquisition unit; 2. Information processing module; 3. Audio control module; 4. Voltage control module; 5. Direction adjustment module; 6. CAN communication module; 7. Vehicle camera module; 8. Sound acquisition module; 9. Low speed alarm. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Example 1 This invention provides a low-speed alarm control system for electric vehicles, such as... Figure 3 As shown, the control system includes: Data acquisition unit 1 is configured to collect vehicle speed information, vehicle surrounding environment information, and vehicle surrounding sound information. Specifically, the data acquisition unit 1 includes: CAN communication module 6 is configured to collect vehicle speed information; here, the type of CAN communication module 6 is, for example, a CAN bus.

[0026] The vehicle-mounted camera module 7 is configured to collect information about the environment surrounding the vehicle; here, the type of vehicle-mounted camera module 7 is, for example, a vehicle-mounted camera, and its model is, for example, Corestar CR-M01A.

[0027] The sound acquisition module 8 is configured to acquire sound information around the vehicle; here, the type of the sound acquisition module 8 is, for example, a sound sensor.

[0028] Information processing module 2 is communicatively connected to data acquisition unit 1. Information processing module 2 is configured to acquire ambient sound information of the vehicle when it is determined that the low speed alarm needs to play a prompt sound. Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve. Obtain the frequency peak and the corresponding sound pressure level from the frequency-sound pressure curve; When the frequency peak is determined to be within the preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset prompt tone frequency, the characteristic frequency band corresponding to the frequency peak is calculated. The characteristic frequency band range is obtained based on the characteristic frequency band and frequency peak value; Here, the type of information processing module 2 is, for example, a telematics box (T-BOX).

[0029] The audio control module 3 is communicatively connected to the information processing module 2. The audio control module 3 is configured to adjust and play the preset prompt tone using a first method, a second method, or a third method when the frequency of the preset prompt tone falls within a characteristic frequency band. Here, the audio control module 3 may be, for example, an audio controller, and its model may be, for example, the Yiyelang X6.

[0030] The first method includes: When the sound pressure level corresponding to the frequency peak is greater than the first threshold, or when the frequency peak is equal to the frequency of the preset prompt tone, the low-speed alarm generates a sound that is opposite in phase and has the same frequency as the frequency peak; here, the first threshold is the set minimum value of external noise passing by the vehicle. The second method includes: When the frequency of the preset prompt tone is determined to be within the first preset range, the sound pressure level of the preset prompt tone is increased to match the sound pressure level corresponding to the frequency peak. The third method includes: When the frequency of the preset prompt tone is determined to be within the second preset range, the sound pressure level of the preset prompt tone is increased, and the frequency of the preset prompt tone is decreased or increased. For detailed steps on adjusting the preset prompt sounds using the three methods described above, please refer to Example 2.

[0031] Wherein, twice the absolute value of the difference between the upper limit of the first preset range and the upper limit of the second preset range equals the characteristic frequency band; and twice the absolute value of the difference between the lower limit of the first preset range and the lower limit of the second preset range equals the characteristic frequency band.

[0032] Through the cooperation of data acquisition unit 1, information processing module 2 and audio control module 3, the sound pressure level and frequency of the low-speed alarm 9 can be adjusted in real time according to different situations, avoiding the masking effect of ambient noise around the vehicle, ensuring the recognizability of the alarm sound, making the adjustment method more flexible and applicable, and effectively reducing safety risks.

[0033] Furthermore, it also includes a voltage control module 4, which is communicatively connected to the audio control module 3. This module is configured to adjust the voltage of the low-speed alarm 9 according to the adjusted preset prompt tone, thereby changing the current of the low-speed alarm 9 and thus altering the volume of the adjusted preset prompt tone, making the played prompt tone more easily recognizable by pedestrians or other living beings. Here, the voltage control module 4 is, for example, a voltage controller, with a model such as the Luming Md618735.

[0034] Furthermore, it also includes: a direction adjustment module 5, which is communicatively connected to the audio control module 3 and configured to adjust the playback direction of the preset prompt tone according to the surrounding environment information of the vehicle.

[0035] Here, the type of the direction adjustment module 5 is, for example, a drive motor. The drive shaft of the drive motor is connected to the housing of the low-speed alarm 9. The control end of the drive motor is communicatively connected to the audio control module 3. Based on the environmental information around the vehicle, the position of the organism relative to the vehicle is obtained. The drive motor drives the low-speed alarm 9 to move, changing the angle of the low-speed alarm 9, and thus changing the playback direction of the low-speed alarm 9 so that its playback direction can be towards the organism, making the alarm sound easier for pedestrians and other organisms to recognize, thereby reducing safety risks.

[0036] Example 2 like Figure 1 As shown, the present invention provides a control method for a low-speed alarm in an electric vehicle, which is based on the control system for a low-speed alarm in an electric vehicle described in Embodiment 1. The control method includes the following steps: S10. When it is determined that the low-speed alarm needs to play a prompt sound, acquire the sound information around the vehicle; here, the sound information around the vehicle refers to the environmental noise data around the vehicle; the sound information around the vehicle is acquired by the vehicle-mounted camera module 7.

[0037] Furthermore, such as Figure 2 As shown, determining that the low-speed alarm needs to play a prompt sound involves the following steps: S101. Obtain vehicle speed information; Here, vehicle speed information is collected by CAN communication module 6. S102. When the vehicle speed information meets the first trigger condition, calculate the vehicle safety distance based on the vehicle speed information; if the vehicle speed information does not meet the first trigger condition, the low speed alarm will not work.

[0038] The first triggering condition is specified according to national standards, which is that the vehicle's forward speed is within the range of 0-20 km / h or the vehicle is in reverse gear. The safe distance between vehicles is calculated using the following formula: ; Where s is the safe distance between vehicles, v is the vehicle speed, and a is the braking acceleration.

[0039] The safe distance between vehicles is related to the vehicle's real-time speed. Taking pedestrians as an example, the distance between pedestrians and vehicles is divided into three types: the first is the safe distance, which ranges from 0 to 1.6 meters; the second is the pre-warning distance, which ranges from 1.6 to 3 meters; and the third is the monitoring distance, which ranges from more than 3 meters. When a pedestrian is within the safe distance, an alarm sound should be emitted to the pedestrian; when a pedestrian is within the pre-warning distance, a pre-warning sound should be emitted and the alarm sound should be prepared; and when a pedestrian is within the monitoring distance, no alarm sound is required.

[0040] For example, if a vehicle is set to brake suddenly at its maximum speed of 20 km / h, the safe distance for the vehicle is calculated using the formula. ,in, a = 9.65 m / s 2 This value can be obtained based on the experience of those skilled in the art; therefore, the braking distance required for the vehicle to come to a complete stop is 1.6m, which is the vehicle safety distance. Calculating the vehicle safety distance through the above process, and determining whether there are any living organisms within the vehicle's safety distance range to decide whether an alarm is needed, can reduce energy waste, effectively improve the accuracy of alarms, and ensure the safety of pedestrians, animals, etc.

[0041] S103. Obtain information about the vehicle's surrounding environment within a safe distance range; here, the information about the vehicle's surrounding environment includes: non-living things and living things. Non-living things include trash cans, trees, etc.; living things include pedestrians, cyclists, animals, etc.

[0042] S104. When the vehicle's surrounding environment information meets the second triggering condition, the low-speed alarm is required to play a prompt sound. If the vehicle's surrounding environment information does not meet the second triggering condition, i.e., the vehicle's surrounding environment information only contains non-living things, or neither non-living things nor living things are contained, the low-speed alarm will not work.

[0043] The second triggering condition is identifying an object in the vehicle's surrounding environment that requires an audible warning.

[0044] S20. Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve; the FFT algorithm is the Fast Fourier Transform (FFT) algorithm.

[0045] S30. Obtain the frequency peak and the corresponding sound pressure level from the frequency-sound pressure curve. Here, the golden section algorithm is used for fine search to obtain the frequency peak in the frequency-sound pressure curve.

[0046] It should be noted that the masking effect refers to the phenomenon where the auditory perception of a weaker sound (the masked sound) is affected by a stronger sound (the masking sound). The auditory response is only sensitive to the most prominent sound, while the response is less sensitive to insensitive sounds. This invention primarily considers the masking effect of pure tones in ambient sound.

[0047] S40. When it is determined that the frequency peak is within the preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any frequency of the preset prompt tone, the characteristic frequency band corresponding to the frequency peak is calculated. It can be seen from the fact that the frequency peak may have a masking effect on the frequency of the preset prompt tone, and further judgment is needed based on the characteristic frequency band.

[0048] Here, the preset frequency range is, for example, 0.7kHz to 9kHz, meaning that the ambient sound between 0.7kHz and 9kHz is set to mask the alert tone. Furthermore, within this frequency range, the hearing threshold of the pure tone is significantly increased; the closer to the frequency of the masking sound, the greater the masking effect. In the frequency range below 0.7kHz and above 9kHz, the masking sound has almost no effect. The characteristic frequency band calculation model was proposed by Zwicker et al. The preset alert tone refers to the initial alert tone of the low-speed alarm. The characteristic frequency band refers to the bandwidth of the total noise power that provides the masking effect, centered on the pure tone frequency, when noise masks a certain pure tone.

[0049] Specifically, the characteristic frequency band can be calculated using a characteristic frequency band calculation model, which is expressed by the following formula: ; Wherein, CBW is the characteristic frequency band, f e The center frequency.

[0050] S50. Based on the characteristic frequency band and frequency peak value, the characteristic frequency band range is obtained; here, the characteristic frequency band range is... ; S60. When it is determined that the frequency of the preset prompt tone is within the characteristic frequency band, the preset prompt tone is adjusted and played using the first method, the second method, or the third method. If the frequency of the preset prompt tone does not fall within the characteristic frequency band, it means that the surrounding sounds of the vehicle will not mask the preset prompt tone, and no adjustment is needed; it can be played directly. If the frequency of the preset prompt tone falls within the characteristic frequency band, it means that the surrounding sounds of the vehicle will mask the preset prompt tone. In order to more effectively alert pedestrians, cyclists, and other living beings, the frequency of the preset prompt tone needs to be adjusted so that the adjusted frequency can avoid the masking effect of the surrounding sounds of the vehicle, thereby playing a prompt tone that can better warn pedestrians and other living beings.

[0051] Before adjusting the preset warning tone, it is important to clarify that the design of the warning tone must comply with the requirements of GBT 37153-2018 "Low-speed Warning Tones for Electric Vehicles" regarding sound pressure level and frequency. For example, when the vehicle speed is 10 km / h, the total sound pressure level of the warning tone should not be less than 52 dB(A), and when the vehicle speed is 20 km / h, the total sound pressure level of the warning tone should not be less than 58 dB(A). Furthermore, it must comply with the requirements of GB1495-2002 "Limits and Measurement Methods for External Noise of Automobiles During Acceleration", such as external noise levels being less than 75 dB(A).

[0052] The first method includes the following steps: When the sound pressure level corresponding to the frequency peak is greater than the first threshold, or when the frequency peak is equal to the frequency of the preset prompt tone, the low-speed alarm generates a sound that is opposite in phase and has the same frequency as the frequency peak. Here, the first threshold is the minimum value of the external noise passing by the vehicle, which is less than 75dB(A) as required by GB1495-2002 "Limits and Measurement Methods for External Noise of Automobiles During Acceleration".

[0053] Specifically, when the sound pressure level corresponding to the frequency peak is greater than the first threshold, GB1495-2002 "Limits and Measurement Methods for External Noise of Automobiles During Acceleration" requires that the external noise be less than 75 dB(A). Furthermore, increasing the sound pressure level of the warning tone to avoid environmental noise masking would cause greater environmental pollution, contradicting the original design intent of this invention. Also, when the frequency peak and the preset warning tone frequency are the same, a wider frequency shift step is required, making this method unsuitable for avoiding the masking effect. This invention, however, utilizes a low-speed alarm to generate a sound with the opposite phase and the same frequency as the frequency peak. The first method employs active noise reduction, using the sound generated by the low-speed alarm as the final warning tone to effectively warn pedestrians and other living organisms, reducing safety risks while simultaneously reducing environmental noise pollution.

[0054] The second method includes the following steps: When the frequency of the preset prompt tone is determined to be within a first preset range, the sound pressure level of the preset prompt tone is increased to match the sound pressure level corresponding to the peak frequency; here, the first preset range is, for example, [missing information]. .

[0055] Because the frequency of the preset prompt tone is far from the frequency peak, that is, the frequency of the preset prompt tone belongs to... The masking effect is relatively small, so simply increasing the sound pressure level of the preset warning tone to the same level as the peak frequency is sufficient to avoid the masking effect of sounds around the vehicle; here, the sound pressure level of the preset warning tone is increased, for example... ,in, To preset the sound pressure level of the prompt tone, The first method refers to the sound pressure level corresponding to the frequency peak. The second method mainly focuses on frequencies farther from the frequency peak, adjusting the sound pressure level by directly increasing it. The adjusted sound pressure level is then played as the final warning tone, which can also effectively alert pedestrians and other living beings, reducing safety risks.

[0056] The third method includes the following steps: When the frequency of the preset prompt tone is determined to be within a second preset range, the sound pressure level of the preset prompt tone is increased, and the frequency of the preset prompt tone is decreased or increased; here, the second preset range is, for example, [missing information]. ; When the frequency of the preset prompt tone is close to the frequency peak, that is, when the frequency of the preset prompt tone is at... When the sound pressure level of the preset prompt tone is within the range, the masking effect is relatively large. If only the sound pressure level of the preset prompt tone is increased, it cannot be guaranteed that the masking effect of the preset prompt tone corresponding to the sound around the vehicle can be completely avoided. Therefore, the frequency of the preset prompt tone should be moved away from the frequency peak first, and then the sound pressure level of the preset prompt tone should be increased to the sound pressure level corresponding to the frequency peak in order to achieve the purpose of avoiding the masking effect.

[0057] Specifically, it determines the frequency of the preset prompt tone. At that time, increase the sound pressure level of the preset prompt tone, for example, increase That is, the second threshold is the difference between the sound pressure level corresponding to the frequency peak and the sound pressure level of the preset prompt, and the frequency of the preset prompt tone is reduced, for example, by at least reducing , where f is the frequency of the preset prompt tone.

[0058] Determine the frequency of the preset prompt tone. At that time, increase the sound pressure level of the preset prompt tone, for example, increase That is, the second threshold is the difference between the sound pressure level corresponding to the frequency peak and the sound pressure level of the preset prompt, and the frequency of the preset prompt is increased, for example, by at least increasing the frequency of the preset prompt. .

[0059] The example ranges of the first preset range and the second preset range mentioned above conform to the following: twice the absolute value of the difference between the upper limit of the first preset range and the upper limit of the second preset range equals the characteristic frequency band; and twice the absolute value of the difference between the lower limit of the first preset range and the lower limit of the second preset range equals the characteristic frequency band.

[0060] Because the sounds around a vehicle are uncertain and diverse, a single adjustment scheme cannot meet the actual needs. This invention designs the above three adjustment schemes, which can adjust the sound pressure level and frequency of the prompt sound in real time according to different situations, avoid the masking effect of environmental noise around the vehicle, ensure the recognizability of the prompt sound, make the adjustment methods more flexible and more applicable, and effectively reduce safety risks.

[0061] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A low-speed alarm control system for electric vehicles, characterized in that, include: The data acquisition unit is configured to collect vehicle speed information, vehicle surrounding environment information, and vehicle surrounding sound information. An information processing module is communicatively connected to the data acquisition unit. The information processing module is configured to acquire ambient sound information of the vehicle when it is determined that the low-speed alarm needs to play a prompt sound. Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve. Obtain the frequency peak value and the sound pressure level corresponding to the frequency peak value in the frequency-sound pressure curve; When it is determined that the frequency peak is within a preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset prompt tone frequency, the characteristic frequency band corresponding to the frequency peak is calculated. The characteristic frequency band range is obtained based on the characteristic frequency band and the frequency peak value; An audio control module is communicatively connected to the information processing module. The audio control module is configured to adjust and play the preset prompt tone using a first method, a second method, or a third method when the frequency of the preset prompt tone is within a characteristic frequency band. The first method includes the following steps: When the sound pressure level corresponding to the frequency peak is greater than a first threshold, or when the frequency peak is equal to the frequency of the preset prompt tone, the low-speed alarm generates a sound that is opposite in phase and has the same frequency as the frequency peak; the first threshold is a set minimum value of external noise passing by the vehicle. The second method includes the following steps: When it is determined that the frequency of the preset prompt tone is within a first preset range, the sound pressure level of the preset prompt tone is increased to be consistent with the sound pressure level corresponding to the peak frequency. The third method includes the following steps: When it is determined that the frequency of the preset prompt tone is within the second preset range, the sound pressure level of the preset prompt tone is increased, and the frequency of the preset prompt tone is decreased or increased; The absolute value of the difference between the upper limit of the first preset range and the upper limit of the second preset range is equal to twice the feature frequency band; and the absolute value of the difference between the lower limit of the first preset range and the lower limit of the second preset range is equal to twice the feature frequency band.

2. The electric vehicle low-speed alarm control system according to claim 1, characterized in that, The data acquisition unit includes: The CAN communication module is configured to collect vehicle speed information. Vehicle-mounted camera module, configured to collect information about the environment surrounding the vehicle; The sound acquisition module is configured to collect sound information around the vehicle.

3. The electric vehicle low-speed alarm control system according to claim 1, characterized in that, Also includes: A voltage control module, which is communicatively connected to the audio control module, is configured to adjust the voltage of the low-speed alarm according to the adjusted preset prompt tone, thereby changing the current of the low-speed alarm and thus changing the volume of the adjusted preset prompt tone.

4. The electric vehicle low-speed alarm control system according to claim 1, characterized in that, Also includes: A direction adjustment module, which is communicatively connected to the audio control module, is configured to adjust the playback direction of the preset prompt tone based on information about the vehicle's surrounding environment.

5. A method for controlling a low-speed alarm for an electric vehicle, implemented based on a low-speed alarm control system for an electric vehicle as described in any one of claims 1 to 4, characterized in that, The control method includes the following steps: When it is determined that the low-speed alarm needs to play a prompt tone, obtain the sound information around the vehicle; Based on the FFT algorithm, the sound information around the vehicle is converted into a frequency-sound pressure curve. Obtain the frequency peak value and the sound pressure level corresponding to the frequency peak value in the frequency-sound pressure curve; When it is determined that the frequency peak is within a preset frequency range and the sound pressure level corresponding to the frequency peak is greater than or equal to the sound pressure level of any preset prompt tone frequency, the characteristic frequency band corresponding to the frequency peak is calculated. The characteristic frequency band range is obtained based on the characteristic frequency band and the frequency peak value; When it is determined that the frequency of the preset prompt tone is within the characteristic frequency band, the preset prompt tone is adjusted and played using the first method, the second method, or the third method. The first method includes the following steps: When the sound pressure level corresponding to the frequency peak is greater than a first threshold, or when the frequency peak is equal to the frequency of the preset prompt tone, the low-speed alarm generates a sound that is opposite in phase and has the same frequency as the frequency peak; the first threshold is a set minimum value of external noise passing by the vehicle. The second method includes the following steps: When it is determined that the frequency of the preset prompt tone is within a first preset range, the sound pressure level of the preset prompt tone is increased to be consistent with the sound pressure level corresponding to the peak frequency. The third method includes the following steps: When it is determined that the frequency of the preset prompt tone is within the second preset range, the sound pressure level of the preset prompt tone is increased, and the frequency of the preset prompt tone is decreased or increased; The absolute value of the difference between the upper limit of the first preset range and the upper limit of the second preset range is equal to twice the feature frequency band; and the absolute value of the difference between the lower limit of the first preset range and the lower limit of the second preset range is equal to twice the feature frequency band.

6. The method for controlling a low-speed alarm for an electric vehicle according to claim 5, characterized in that, Determining that a low-speed alarm needs to play a prompt sound involves the following steps: Obtain vehicle speed information; When the vehicle speed information is determined to meet the first triggering condition, the vehicle safety distance is calculated based on the vehicle speed information. Obtain information about the vehicle's surrounding environment within the vehicle's safe distance range; When the environmental information surrounding the vehicle is determined to meet the second triggering condition, the low-speed alarm is required to play a prompt sound.

7. The method for controlling a low-speed alarm for an electric vehicle according to claim 6, characterized in that, Calculate the safe distance between vehicles using the following formula: ； Where s is the safe distance between vehicles, v is the vehicle speed, and a is the braking acceleration.

8. The method for controlling a low-speed alarm for an electric vehicle according to claim 6, characterized in that, The first triggering condition is that the vehicle's forward speed is within the range of 0-20 km / h or the vehicle is in reverse gear; the second triggering condition is that an object requiring a warning sound is identified in the environmental information surrounding the vehicle.

9. A method for controlling a low-speed alarm for an electric vehicle according to claim 5, characterized in that, Obtaining the frequency peak value in the frequency-sound pressure curve specifically includes the following steps: The frequency peak value in the frequency-sound pressure curve is obtained by using the golden section algorithm for fine search.

10. A storage medium, one of the computer-readable storage media, characterized in that, It stores a computer program, which, when executed by a processor, implements the electric vehicle low-speed alarm control method as described in any one of claims 5 to 9.

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