Ultrasonic sensor echo signal detection method, chip and device

Abstract

Embodiments of the present application provide an echo signal detection method, a chip and an apparatus of an ultrasonic sensor. The method comprises periodically reading a first point signal and a second point signal of an echo signal according to a preset reading frequency, the first point signal serving as a reference signal and the second point signal serving as a comparison signal; determining whether the reference signal and the comparison signal are target signals based on amplitude information of the reference signal and the comparison signal; when the reference signal and the comparison signal are the target signals, updating the preset reading frequency to a first frequency and updating a quantity of the target signals; when the reference signal and the comparison signal are not the target signals, updating the preset reading frequency to a second frequency and restoring or maintaining the quantity of the target signals to an initial value; the first frequency is not less than the second frequency; and determining whether a target echo signal appears based on whether the quantity of the target signals is greater than a preset value. The efficiency of echo detection is improved.

Description

Technical Field

[0001] This application relates to the field of ultrasonic technology, specifically to a method for detecting echo signals of an ultrasonic sensor, an ultrasonic sensor chip, and an automotive ultrasonic radar device. Background Technology

[0002] To improve distance measurement and assist in reversing or parking, vehicles are typically equipped with reversing assist devices. These devices consist of an ultrasonic transmitter and an ultrasonic receiver. The ultrasonic transmitter and receiver can be integrated into a single ultrasonic transducer, or they can be separate components. When the emitted ultrasonic signal is reflected by an obstacle or object near the vehicle, the echo signal can be detected in the received signal. The distance to the obstacle can then be calculated using the time difference between the emitted and received echo signals.

[0003] In some technologies, echo signal detection requires waiting until all reflected signals have been received before processing the received signal and comparing it to a threshold to determine if it is an echo. This method, which waits until all reflected signals are received before processing all received signals, is slow and reduces the efficiency of echo detection. Alternatively, some technologies perform peak extraction on the received signal and compare the extracted peak value to a preset threshold to determine if it is an echo. This method requires extracting the peak value of the received signal, is complex to implement, and also requires all reflected signals to be received before echo detection, resulting in slow and inefficient echo detection. Summary of the Invention

[0004] In view of this, this application provides a method for detecting echo signals of an ultrasonic sensor, an ultrasonic sensor chip, and an automotive ultrasonic radar device, in order to solve the problem of low echo detection efficiency in the prior art.

[0005] In a first aspect, embodiments of this application provide a method for detecting echo signals from an ultrasonic sensor, comprising:

[0006] The first and second point signals of the echo signal are periodically read according to a preset reading frequency. The first point signal is used as a reference signal and the second point signal is used as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time.

[0007] Based on the amplitude information of the reference signal and the comparison signal, it is determined whether the reference signal and the comparison signal are target signals; if the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals is updated; if the reference signal and the comparison signal are not target signals, the preset reading frequency is updated to a second frequency, and the number of target signals is restored to or maintained at the initial value; the first frequency is not less than the second frequency.

[0008] Whether a target echo signal appears is determined based on whether the number of target signals is greater than a preset value.

[0009] Secondly, embodiments of this application provide an ultrasonic sensor chip, including: a sampling circuit, a filtering circuit, and a readout processing circuit;

[0010] The sampling circuit is coupled to the ultrasonic transducer to sample the echo signal;

[0011] The filtering circuit is electrically connected to the sampling circuit and is used to filter the echo signal input to the sampling circuit to output an echo signal of a preset frequency.

[0012] The reading processing circuit is electrically connected to the filtering circuit and is used to determine whether the input echo signal of the preset frequency is the target echo signal.

[0013] The reading processing circuit includes a reading module, a comparison module, a control module, and a judgment module.

[0014] The reading module is electrically connected to the filtering circuit and is used to periodically read the first point signal and the second point signal of the echo signal at the preset frequency according to the preset reading frequency. The first point signal is used as a reference signal and the second point signal is used as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time.

[0015] The comparison module is electrically connected to the reading module and is used to receive the amplitude information of the reference signal and the comparison signal input by the reading module, and to determine whether the reference signal and the comparison signal are target signals;

[0016] The control module, electrically connected to the comparison module and the reading module, is used to receive the comparison result from the comparison module. When the reference signal and the comparison signal are target signals, the preset reading frequency of the reading module is updated to a first frequency, and the number of target signals is updated. When the reference signal and the comparison signal are not target signals, the preset reading frequency of the reading module is updated to a second frequency, and the number of target signals is restored to or maintained at its initial value. The first frequency is not less than the second frequency.

[0017] The judgment module is electrically connected to the control module, reads the number of target signals from the control module, and determines that a target echo signal has appeared if the number of target signals is greater than a preset value.

[0018] Thirdly, embodiments of this application provide an automotive ultrasonic radar device, including: an ultrasonic transducer and the ultrasonic sensor chip described in the second aspect above;

[0019] The ultrasonic sensor chip is electrically connected to the ultrasonic transducer and is used to determine whether the echo signal received by the ultrasonic transducer is the target echo signal.

[0020] The scheme provided in this application involves periodically reading a first point signal and a second point signal of the echo signal at a preset reading interval. The first point signal serves as a reference signal, and the second point signal serves as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time. Based on the amplitude information of the reference signal and the comparison signal, it is determined whether the reference signal and the comparison signal are target signals. If the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals is updated. If the reference signal and the comparison signal are not target signals, the preset reading frequency is updated to a second frequency, and the number of target signals is restored to or maintained at its initial value. The first frequency is not less than the second frequency. Whether the number of target signals is greater than a preset value is used to determine whether a target echo signal has appeared. That is, in this application embodiment, by periodically reading the reference signal and the comparison signal to determine the target echo signal, it is not necessary to wait for the reflected signal to be completely received before determining the target echo signal, which can greatly reduce the amount of data read and reduce hardware overhead. Furthermore, it eliminates the need to wait until all transmitted signals have been received or peak values ​​have been extracted before performing the corresponding threshold judgment, thus improving the processing speed of echo judgment and thereby increasing the efficiency of echo detection. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an automotive ultrasonic radar device provided in an embodiment of this application;

[0023] Figure 2a This is a schematic diagram of the structure of an ultrasonic sensor chip provided in an embodiment of this application;

[0024] Figure 2b This is a schematic diagram of another ultrasonic sensor chip provided in an embodiment of this application;

[0025] Figure 3 A flowchart illustrating an echo signal detection method for an ultrasonic sensor chip provided in this application embodiment;

[0026] Figure 4 A schematic diagram illustrating a scenario for an echo signal detection method for an ultrasonic sensor chip provided in an embodiment of this application;

[0027] Figure 5 A schematic diagram of a scenario for another method of detecting echo signals of an ultrasonic sensor chip provided in an embodiment of this application;

[0028] Figure 6a A schematic diagram of a scenario for another method of detecting echo signals of an ultrasonic sensor chip provided in an embodiment of this application;

[0029] Figure 6b A schematic diagram of a scenario for another method of detecting echo signals of an ultrasonic sensor chip provided in an embodiment of this application;

[0030] Figure 7a A schematic diagram of a scenario for another method of detecting echo signals of an ultrasonic sensor chip provided in an embodiment of this application;

[0031] Figure 7b A schematic diagram of a scenario for another method of detecting echo signals of an ultrasonic sensor chip provided in an embodiment of this application;

[0032] Figure 8 This is a schematic diagram of another ultrasonic sensor chip provided in an embodiment of this application;

[0033] Figure 9a This is a schematic diagram of another ultrasonic sensor chip provided in an embodiment of this application;

[0034] Figure 9b This is a schematic diagram of another ultrasonic sensor chip provided in an embodiment of this application;

[0035] Figure 10 This is a schematic diagram of another automotive ultrasonic radar device provided in an embodiment of this application;

[0036] Figure 11 This is a schematic diagram of another automotive ultrasonic radar device provided in an embodiment of this application. Detailed Implementation

[0037] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0038] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0039] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0040] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0041] Before providing a detailed description of the embodiments of this application, the terms used or possibly used in the embodiments of this application will first be explained.

[0042] ADC (Analog-to-digital converter, A / D or AtoD) is a device that converts continuously changing analog signals into discrete digital signals.

[0043] ECU (Electronic Control Unit): Also known as "vehicle computer" or "on-board computer." Like a regular computer, it consists of a microprocessor chip (MCU), memory (ROM, RAM), input / output interfaces (I / O), analog-to-digital converters (A / D), and large-scale integrated circuits for shaping and driving.

[0044] PCB (Printed Circuit Board) is an important electronic component. It serves as the support for electronic components and the carrier for the electrical interconnection of these components.

[0045] FPC (Flexible Printed Circuit) is a type of highly reliable and extremely flexible printed circuit board made with polyimide or polyester film as the substrate.

[0046] CAN (Controller Area Network) is short for Controller Area Network.

[0047] LIN (Local Interconnect Network). LIN's main function is to provide auxiliary functions for CAN bus networks. LIN bus is a common Class A network protocol.

[0048] PTP (Point-to-Point) is a link-layer protocol designed for simple links that transmit data packets between peer units. This type of link provides full-duplex operation and delivers data packets sequentially.

[0049] In some technologies, echo signal detection requires waiting until all reflected signals have been received before processing the received signal and comparing it to a threshold to determine if it is an echo. This method requires processing all received signals after all reflected signals have been received, resulting in slow processing speed and reduced efficiency. Alternatively, some technologies perform peak extraction on the received signal and compare the extracted peak value to a preset threshold to determine if it is an echo. This method requires extracting the peak value of the received signal, making it complex to implement, and also requires all reflected signals to be received before echo detection, resulting in slow and inefficient echo signal detection.

[0050] To address the aforementioned problems, this application provides an echo signal detection method for an ultrasonic sensor, an ultrasonic sensor chip, and an automotive ultrasonic radar device. The method involves periodically reading a first point signal and a second point signal of the echo signal at a preset reading interval. The first point signal serves as a reference signal, and the second point signal serves as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time. Based on the amplitude information of the reference signal and the comparison signal, it is determined whether the reference signal and the comparison signal are target signals. If the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals is updated. If the reference signal and the comparison signal are not target signals, the preset reading frequency is updated to a second frequency, and the number of target signals is restored to or maintained at its initial value. The first frequency is not less than the second frequency. Whether a target echo signal appears is determined based on whether the number of target signals is greater than a preset value. In other words, in this application embodiment, by periodically reading the reference signal and the comparison signal to determine the target echo signal, it is not necessary to wait for the reflected signal to be completely received before determining the target echo signal, which can greatly reduce the amount of data read and reduce hardware overhead. Furthermore, it eliminates the need to wait for all transmitted signals to be received or for peak values ​​to be extracted before performing the corresponding threshold judgment, thus improving the processing speed of echo judgment and consequently increasing the efficiency of echo detection. A detailed explanation follows.

[0051] See Figure 1 This is a schematic diagram of the structure of an automotive ultrasonic radar device according to an embodiment of this application. The automotive ultrasonic radar device includes a substrate 10, an ultrasonic sensor chip 20, an ultrasonic transmitting sensor 30, and an ultrasonic receiving sensor 40. In some embodiments, the substrate 10 may be a PCB board or an FPC (Flexible Printed Circuit) board. The ultrasonic sensor chip 20 is disposed on the substrate 10. The ultrasonic sensor chip 20 includes a body 201, an IC (Integrated Circuit) circuit 202 located within the body, and pins located outside the body 201 that are electrically connected to the IC circuit 202. The pins include at least one first pin 2031, at least one second pin 2032, and at least one third pin 2033. The IC circuit 202 is connected to the ultrasonic transmitting sensor 30 through at least one first pin 2031. The IC circuit 202 is electrically connected to the main control ECU or microprocessor chip in the vehicle through at least one second pin 2032. In some embodiments, the IC circuit 202 is electrically connected to the microprocessor chip in the vehicle via a CAN bus, LIN, or PTP method through at least one second pin 2032. IC circuit 202 is connected to ultrasonic receiving sensor 40 via at least one third pin 2033.

[0052] In some embodiments, the ultrasonic transmitting sensor 30 and the ultrasonic receiving sensor 40 can be integrated into a single sensor, meaning that one ultrasonic sensor can both transmit and receive ultrasonic signals. In other words, one ultrasonic sensor can function as both an ultrasonic transmitting sensor and an ultrasonic receiving sensor, in which case the third pin 2033 is equivalent to the first pin 2031.

[0053] See Figure 2aThis is a schematic diagram of the structure of an ultrasonic sensor chip provided in an embodiment of this application. The IC circuit 202 in the ultrasonic sensor chip 20 includes a preamplifier circuit 2021, a main control circuit 2022, a drive circuit 2023, a readout processing circuit 2024, and a timer 2025. After receiving a trigger signal from a host computer, such as a car's main control ECU or microprocessor chip, the main control circuit 2022 controls the drive circuit 2023 to generate an ultrasonic excitation signal, which drives the ultrasonic transmitting sensor 30 to emit ultrasonic waves. After the ultrasonic transmitting sensor 30 emits an ultrasonic signal, the ultrasonic signal is reflected after encountering an obstacle. The ultrasonic receiving sensor 40 begins to receive the reflected ultrasonic signal after the ultrasonic transmitting sensor 30 emits the ultrasonic signal. After receiving the emitted ultrasonic signal, the ultrasonic receiving sensor 40 can transmit the received ultrasonic signal to the preamplifier circuit 2021 in the IC circuit 202. Because the ultrasonic receiving sensor 40 continuously receives ultrasonic signals from the environment, and these signals include environmental interference signals and ultrasonic signals emitted by other ultrasonic transmitting sensors, the preamplifier circuit 2021 needs to sample, filter, and amplify the received ultrasonic signals. The preamplifier circuit 2021 can improve the filtering accuracy to filter out ultrasonic signals within a preset frequency range, or it can function as a high-pass, low-pass, or band-pass filter to retain only ultrasonic signals within the preset frequency range. This preset frequency range includes the frequencies of the ultrasonic signals emitted by the ultrasonic transmitting sensor 30. The preamplifier circuit 2021 transmits the processed ultrasonic signal to the reading and processing circuit 2024. The reading and processing circuit 2024 reads and processes the received ultrasonic signal to detect whether it is a target echo signal. If the received ultrasonic signal is detected as a target echo signal, it is determined that an echo signal emitted by the ultrasonic transmitting sensor 30 and emitted by an obstacle has been received. After the drive circuit 2023 finishes transmitting the excitation signal, the timer 2025 starts timing and stops timing when the reading and processing circuit determines that the target echo signal has been received. The main control circuit 2022 calculates the distance to the obstacle based on the relationship between the timer's timing and the propagation speed of the ultrasonic signal. After obtaining the distance information, the main control circuit 2022 sends the distance information to the main control ECU or microprocessor chip in the vehicle. After receiving the distance information, the main control ECU or microprocessor chip in the vehicle can determine whether to issue a prompt message based on the distance information. Of course, the distance calculation function can also be performed by the microprocessor chip. When the reading and processing circuit 2024 detects the target echo signal, it sends an indication signal indicating that the specified echo signal has been received to the microprocessor chip. The time from the microprocessor chip sending the trigger signal to receiving the indication signal is used as the time reference for calculating the obstacle distance.Meanwhile, the timer in the main control circuit is not used to calculate distance, but to read the echo signal from the processing circuit 2024 for judgment. The timer can be set in the microprocessor chip. Of course, the main control circuit may not have a corresponding timer set. See the following explanation for details.

[0054] In some embodiments, to reduce the size of the ultrasonic sensor chip, the timer 2025 and the readout processing circuit 2024 can be integrated into the main control circuit 2022. (This is in the context of embodiments of this application and...) Figure 2a Taking the integration of timer 2025 and read processing circuit 2024 into main control circuit 2022 as an example, the circuit part of main control circuit 2022 used for driving circuit can be set in different circuits from the part used for processing echo signals, and there is no restriction on the specific setting method.

[0055] In some embodiments, the preamplifier circuit 2021 integrates an amplifier and a filter.

[0056] In some embodiments, when the reading processing circuit 2024 can only process digital signals, the IC circuit 202 of the ultrasonic sensor chip also includes an analog-to-digital converter (ADC) 2026, such as... Figure 2b As shown. The ADC 2026 is located between the preamplifier circuit 2021 and the readout processing circuit 2024. The ADC 2026 converts the ultrasonic signal transmitted by the preamplifier circuit 2021 from an analog signal to a digital signal and transmits it to the readout processing circuit 2024.

[0057] In some embodiments, if the filtering accuracy in the preamplifier circuit 2021 is too low to filter out ultrasonic signals within a preset frequency range, a matched filter 2027 (which can also be a high-precision digital filter) is further provided in the IC circuit 202 of the ultrasonic sensor chip. (See reference...) Figure 2b As shown, the matched filter 2027 is positioned between the ADC 2026 and the readout processing circuit 2024. The matched filter 2027 performs matched filtering on the ultrasonic signal from the digital signal converted by the ADC, detecting ultrasonic signals within a preset frequency range. The detected ultrasonic signal is then transmitted to the readout processing circuit 2024. It is known that the preamplifier circuit 2021 is unnecessary here. The ADC 2026 performs ADC conversion on the echo signal received at pin 2033, the converted signal is then filtered, and the processed signal is input to the readout processing circuit 2024.

[0058] See Figure 3 This is a flowchart illustrating an echo signal detection method provided in an embodiment of this application. The method is applied to the above-mentioned... Figure 2a and Figure 2b The ultrasonic sensor chip shown. (As shown in the image.) Figure 3 As shown, the method includes:

[0059] Step S301: Periodically read the first point signal and the second point signal of the echo signal according to the preset reading interval, and use the first point signal as the reference signal and the second point signal as the comparison signal.

[0060] The reading time interval between the reference signal and the comparison signal is preset.

[0061] In this embodiment, after receiving the reflected ultrasonic signal, the ultrasonic signal within a preset frequency range is found through filtering. This ultrasonic signal may be an environmental interference signal or an ultrasonic signal emitted by other ultrasonic transmitting sensors. Therefore, the received ultrasonic signal needs further detection to determine whether it is the echo signal required by the ultrasonic sensor chip. Based on this, the ultrasonic sensor chip can periodically read the received ultrasonic signal (i.e., the echo signal) at a preset reading frequency to obtain a first point signal and a second point signal. The first point signal is used as a reference signal, and the second point signal is used as a comparison signal. The reading time interval between the reference signal and the comparison signal is preset. That is, when the ultrasonic sensor chip periodically reads the reference signal and the comparison signal at the preset reading frequency, it first reads the reference signal, and after reading the reference signal, it reads the comparison signal after a preset time interval.

[0062] In some embodiments, the ultrasonic sensor chip can amplify and filter the ultrasonic signal received by the ultrasonic receiving sensor to obtain an echo signal within a preset frequency range. This preset frequency range includes the frequencies of the ultrasonic signals emitted by the ultrasonic transmitting sensor. The ultrasonic sensor chip needs to detect whether the echo signal within the preset frequency range is the desired echo signal; therefore, the ultrasonic sensor chip periodically reads the reference signal and comparison signal from the echo signal within the preset frequency range according to a preset reading frequency.

[0063] It should be noted that the preset reading frequency is set before reading the reference signal and the comparison signal. The preset reading frequency can be a fixed frequency value, so the ultrasonic sensor chip directly uses this reading frequency as the reading period to periodically read the reference signal and the comparison signal. This simplifies the related implementation circuitry in the ultrasonic sensor chip and reduces its complexity.

[0064] In some embodiments, the preset reading frequency can also be adjusted in real time. The ultrasonic sensor chip can set the reading frequency based on whether the reference signal and the comparison signal are target signals. For example, when the reference signal and the comparison signal are target signals, the reading frequency can be set to a first frequency; when the reference signal and the comparison signal are not target signals, the reading frequency can be set to a second frequency, and the first frequency is greater than or equal to the second frequency.

[0065] Step S302: Based on the amplitude information of the reference signal and the comparison signal, determine whether the reference signal and the comparison signal are target signals; if the reference signal and the comparison signal are target signals, update the preset reading frequency to the first frequency and update the number of target signals; if the reference signal and the comparison signal are not target signals, update the preset reading frequency to the second frequency and restore or maintain the number of target signals to the initial value.

[0066] The target signal refers to an ultrasonic signal with an amplitude value not less than the corresponding threshold. The first frequency is not less than the second frequency.

[0067] In this embodiment, after each reading of the reference signal and comparison signal, the ultrasonic sensor chip needs to detect whether the read reference signal and comparison signal are the echo signals required by the ultrasonic sensor chip. After reading the reference signal and comparison signal in the current cycle, the ultrasonic sensor chip can detect whether the read reference signal and comparison signal in the current cycle are the target signal. From the start of oscillation to normal oscillation and then to the end, the ultrasonic wave will show a trend of small amplitude to large amplitude, and then from large amplitude to small amplitude, such as... Figure 4 As shown. For accuracy, a wave reaching a certain threshold is used as the reference for receiving the target echo signal. Even waves of the same frequency may contain other interference waves in the received echo signal, and the amplitude of these interference waves is generally small. In this case, an echo signal with a small amplitude cannot be used as the basis for judging the target echo signal; that is, the amplitude of the target echo signal is greater than a certain threshold. Based on this, the ultrasonic sensor chip detects whether the amplitude information of the reference signal and the comparison signal read in the current cycle is not less than the threshold corresponding to the current cycle, to determine whether the reference signal and the comparison signal are the target signal. If the amplitude information of the reference signal and the comparison signal read in the current cycle is not less than the threshold corresponding to the current cycle, then the reference signal and the comparison signal are determined to be the target signal. If the amplitude information of the reference signal and the comparison signal read in the current cycle is less than the threshold corresponding to the current cycle, then the reference signal and the comparison signal are determined not to be the target signal.

[0068] To more accurately determine whether the reference and comparison signals read by the ultrasonic sensor chip are the echo signals required by the chip, it is necessary for multiple consecutive reading cycles to show that the reference and comparison signals are the target signals. Therefore, when the ultrasonic sensor chip determines that the read reference and comparison signals are the target signals, it increments the target signal count by 1, updating the target signal count.

[0069] Alternatively, if the ultrasonic sensor chip determines that the reference signal and comparison signal are not the target signal, it means that the reference signal and comparison signal read in the current cycle are not the target echo signal required by the ultrasonic sensor chip. Since the ultrasonic excitation signal is continuous, the target echo signal should also be continuous. Therefore, if the reference signal and comparison signal read in the current cycle are not the target echo signal required by the ultrasonic sensor chip, then the reference signal and comparison signal read in the previous reading cycles were also not the target echo signal required by the ultrasonic sensor chip. That is, the ultrasonic signal currently received by the ultrasonic sensor chip is not its required target echo signal. Based on this, when the reference signal and comparison signal are not the target signal, the ultrasonic sensor chip needs to restore or maintain the number of target signals to an initial value, such as clearing it to zero or other initial values. For ease of explanation, the initial value is taken as zero. For example, if two target signals appear consecutively, the number of target signals is 2. When a third target signal appears, the number of target signals is recorded as 3. If the next signal is not the target signal, the number of target signals is restored to 0. If the signal that appears is not the target signal, the number of target signals remains at the initial value of 0.

[0070] In some embodiments, even if the reference signal and comparison signal read in the previous reading cycle are determined to be the target signal, if the reference signal and comparison signal read in the current cycle are not the target signal, it means that the ultrasonic signal currently received by the ultrasonic sensor chip is not the target echo signal it needs. Therefore, the ultrasonic sensor chip needs to clear the number of target signals to zero and discard all the reference signals and comparison signals currently read.

[0071] To reduce hardware overhead and increase the accuracy of target echo signal detection, the ultrasonic sensor chip can set the reading frequency based on whether the reference signal and comparison signal are target signals. When the reference signal and comparison signal are target signals, the reading frequency can be set to a first frequency, meaning that readings will be performed at the first frequency cycle during the next reference signal and comparison signal analysis. When the reference signal and comparison signal are not target signals, the reading frequency is set to a second frequency, with the first frequency being greater than or equal to the second frequency, meaning that readings will be performed at the second frequency cycle during the next reference signal and comparison signal analysis. This allows for real-time adjustment of the reading frequency. When the reference signal and comparison signal are target signals, the reading interval can be reduced, increasing the reading frequency and thus reading more reference and comparison signals to determine if it is a target echo signal, improving the accuracy of target echo signal detection. When the reference signal and comparison signal are not target signals, the reading interval can be increased, reducing the reading frequency and thus reducing the amount of data read and hardware overhead.

[0072] The initial reading frequency can be either a first frequency or a second frequency, preferably the first frequency, to improve the accuracy of close-range judgment.

[0073] Because the ultrasonic sensor chip needs to detect whether the amplitude information of the reference signal and comparison signal read in the current cycle is not less than the threshold corresponding to the current cycle, it needs to determine whether the reference signal and comparison signal are target signals. The threshold can be either an amplitude threshold or an amplitude difference threshold. Since, in different reading cycles, for the same two reading moments, the larger the amplitude of the read ultrasonic signal, the larger the amplitude difference between the two reading signal points. Therefore, the amplitude information of the ultrasonic signal can be determined based on the magnitude of the amplitude difference. In this embodiment, when the amplitude difference is greater than the amplitude difference threshold, it indicates that the amplitude information of the read ultrasonic signal meets the amplitude requirements of the target echo signal. Whether the threshold corresponding to the current cycle is an amplitude threshold or an amplitude difference threshold depends on whether the amplitude information of the reference signal is a preset reference value. When the amplitude information of the reference signal is a preset reference value, it is necessary to determine whether the reference signal and comparison signal are target signals based on the amplitude information of the comparison signal. In this case, the threshold corresponding to the current cycle can be determined as the amplitude threshold. If the amplitude information of the reference signal is not a preset reference value, it is necessary to jointly determine whether the reference signal and the comparison signal are target signals based on the amplitude information of both the reference signal and the comparison signal. In this case, the threshold corresponding to the current period can be determined as the amplitude difference threshold. Therefore, when determining whether the reference signal and the comparison signal are target signals, it is necessary to first determine whether the amplitude information of the reference signal is a preset reference value. As a possible implementation, determining whether the reference signal and the comparison signal are target signals based on the amplitude information of the reference signal and the comparison signal includes:

[0074] The system detects whether the amplitude information of the reference signal is a preset reference value; if the amplitude information of the reference signal is a preset reference value, it determines the amplitude threshold corresponding to the current period; it detects whether the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period; if the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period, it determines that the reference signal and the comparison signal are the target signals.

[0075] In this embodiment, the ultrasonic sensor chip first detects whether the amplitude information of the reference signal is a preset reference value. If the amplitude information of the reference signal is the preset reference value, the threshold corresponding to the current period can be determined as the amplitude threshold, and the amplitude information of the comparison signal can be compared with the amplitude threshold corresponding to the current period. At this time, the ultrasonic sensor chip can determine the amplitude threshold corresponding to the current period based on the current time, the reading time of the comparison signal in the current period, the reading time of the reference signal in the current period, or other times in the current period. It can also use the amplitude information read during the clock cycle as the amplitude threshold. The ultrasonic sensor chip detects whether the amplitude of the comparison signal is greater than or equal to the amplitude threshold of the current period. When the amplitude of the comparison signal is greater than or equal to the amplitude threshold corresponding to the current period, it indicates that the amplitude information of the reference signal and the comparison signal read in the current period meets the amplitude requirements of the required echo signal of the ultrasonic sensor chip, and can be determined as the target signal.

[0076] For ease of implementation, the amplitude threshold is set with reference to a preset reference value. That is, the amplitude threshold is a threshold value relative to the preset reference value. Therefore, when the amplitude information of the reference signal is the preset reference value, the relationship between the amplitude information of the comparison signal and the amplitude threshold corresponding to the current period can be used to determine whether the reference signal and comparison signal read in the current period are the target signals.

[0077] It should be understood that the preset reference value is set in advance according to actual needs. The preset reference value can be 0 volts or other values, and this application does not limit it.

[0078] When determining whether a reference signal and a comparison signal are target signals based on their amplitude information, it is necessary to compare their amplitude information with corresponding thresholds. Therefore, when the ultrasonic sensor chip determines that the reference signal is a preset reference value, it needs to further determine the amplitude threshold corresponding to the current period. This can be done in the following way: Determining the amplitude threshold corresponding to the current period includes:

[0079] The amplitude threshold corresponding to the current cycle is determined based on the time interval between the current moment and the moment the ultrasonic signal was emitted.

[0080] Because the energy of an ultrasonic signal gradually decreases over time during transmission, its amplitude also gradually decreases. Therefore, in this embodiment, the amplitude threshold is different in each reading cycle, and the amplitude threshold decreases with increasing time. Furthermore, the closer to the moment the ultrasonic signal is emitted, the larger the amplitude, and thus the larger the amplitude threshold should be. Based on this, different amplitude thresholds can be preset for different time intervals relative to the moment the ultrasonic signal is emitted. For example, if the time interval is within t1 seconds, the amplitude threshold is set to Vth1; if the time interval is greater than t1 seconds but not greater than t2 seconds, the amplitude threshold is set to Vth2; if the time interval is greater than t2 seconds but not greater than t3 seconds, and so on, the amplitude threshold is set to Vth3, where Vth1 is greater than Vth2, and Vth2 is greater than Vth3.

[0081] Because amplitude thresholds corresponding to different time intervals between the time of ultrasonic signal emission are preset, the ultrasonic sensor chip can first determine the time of ultrasonic signal emission. In some embodiments, the ultrasonic sensor chip can trigger a timer to start timing when the ultrasonic signal is emitted from the ultrasonic transmitter, and the ultrasonic sensor chip can directly determine the time of ultrasonic signal emission from the timer. In some embodiments, the ultrasonic sensor chip can obtain the time of ultrasonic signal emission from the ultrasonic transmitter. Of course, the ultrasonic sensor chip can also determine the time of ultrasonic signal emission in other ways, and this application does not limit this. After determining the time of ultrasonic signal emission, the ultrasonic sensor chip can determine the amplitude threshold corresponding to the current period based on the time interval between the current time and the time of ultrasonic signal emission.

[0082] Furthermore, a corresponding timer can be omitted; that is, multiple amplitude thresholds can be pre-stored, and these amplitude thresholds are time-dependent, as described above. However, the storage module only stores amplitude threshold information. During comparison, as the clock changes, threshold information at different addresses in the storage module is read and input into the comparison module for comparison. This method saves hardware circuitry, simplifies the data processing flow, and improves processing speed. In this case, determining the amplitude threshold corresponding to the current cycle includes reading one of the multiple amplitude thresholds according to the clock cycle.

[0083] In other words, multiple pre-set amplitude thresholds are stored in the storage module. These thresholds correspond to different clock cycles, allowing the sensor chip to directly read the stored thresholds as the clock cycle changes. The ultrasonic sensor chip can then obtain the corresponding amplitude threshold based on the current clock cycle to determine whether the reference signal and comparison signal are the target signal.

[0084] As one possible implementation, in the above process, the ultrasonic sensor chip needs to detect whether the amplitude information of the reference signal is a preset reference value. When the amplitude information of the reference signal is not a preset reference value, it determines the amplitude difference threshold corresponding to the current period, and determines the amplitude difference between the reference signal and the comparison signal based on the amplitude information of the reference signal, the amplitude information of the comparison signal, the reading time of the reference signal, and the reading time of the comparison signal. It then detects whether the amplitude difference is not less than the amplitude difference threshold. When the amplitude difference is not less than the amplitude difference threshold, it determines the reference signal and the comparison signal as the target signal.

[0085] When an ultrasonic sensor chip reads data, the amplitude information of the reference signal may not be the preset reference value. That is, if the ultrasonic sensor chip determines that the amplitude information of the reference signal is not the preset reference value, and still determines the threshold corresponding to the current period as the amplitude threshold, then when directly comparing the amplitude information of the comparison signal with the amplitude threshold, the comparison result will be too large due to the reference signal amplitude information not being the preset reference value, leading to inaccurate judgment. Therefore, to reduce misjudgment, the threshold corresponding to the current period can be determined as the amplitude difference threshold. At this time, the amplitude difference threshold corresponding to the current period can be determined based on the current moment, the reading time of the comparison signal in the current period, the reading time of the reference signal in the current period, or other times in the current period. After determining the amplitude difference threshold for the current period, the amplitude difference of the current period needs to be calculated. Then, the ultrasonic sensor chip can calculate the amplitude change between the reference signal and the comparison signal based on the amplitude information of the reference signal, the amplitude information of the comparison signal, the reading time of the reference signal, and the reading time of the comparison signal. For example, ΔV = V0 - V0', where V0 represents the amplitude information of the comparison signal, V0' represents the amplitude information of the reference signal, and ΔV is the amplitude change. When the amplitude difference is not less than the amplitude difference threshold, the reference signal and the comparison signal are determined to be the target signals. Of course, the comparison between the amplitude difference and the amplitude difference threshold can be done in various ways, such as using the formula tanθ = (V0 - V0') / L, where tanθ represents the angle between the amplitude difference of the reference signal and the comparison signal, V0 represents the amplitude information of the comparison signal, V0' represents the amplitude information of the reference signal, and L represents the time interval between the reference signal and the comparison signal. The calculated amplitude difference (angle of difference) between the reference signal and the comparison signal is compared with the amplitude difference threshold (angle of difference threshold) to detect whether the angle of difference between the reference signal and the comparison signal is not less than the angle of difference threshold. If the angle between the reference signal and the comparison signal is not less than the threshold value of the angle between the reference signal and the comparison signal, it means that the amplitude of the ultrasonic signal in the current cycle meets the amplitude requirement of the echo signal, and the reference signal and the comparison signal can be determined as the target signal.

[0086] As one possible implementation, determining the amplitude difference threshold corresponding to the current period includes:

[0087] The amplitude difference threshold corresponding to the current cycle is determined based on the time interval between the current moment and the moment the ultrasonic signal was emitted.

[0088] That is, different amplitude difference thresholds can be preset for different time intervals corresponding to the time of ultrasonic signal emission, and the amplitude difference threshold decreases as time increases. For example, if the time interval between the time of ultrasonic signal emission and the time of emission is within t1 seconds, the amplitude difference threshold is set to K1; if the time interval is greater than t1 seconds but not greater than t2 seconds, the amplitude difference threshold is K2; and if the time interval is greater than t2 seconds but not greater than t3 seconds, the amplitude difference threshold is K3, where K1 is greater than K2, and K2 is greater than K3. Thus, since amplitude difference thresholds corresponding to different time intervals corresponding to the time of ultrasonic signal emission are preset, the ultrasonic sensor chip can first determine the time of ultrasonic signal emission. In some embodiments, the ultrasonic sensor chip can trigger a timer to start timing when the ultrasonic signal is emitted from the ultrasonic transmitter, and the ultrasonic sensor chip can directly determine the time of ultrasonic signal emission from the timer. In some embodiments, the ultrasonic sensor chip can obtain the time of ultrasonic signal emission from the ultrasonic transmitter. Of course, the ultrasonic sensor chip can also determine the time of ultrasonic signal emission in other ways, and this application does not limit this. After determining the moment the ultrasonic signal is emitted, the ultrasonic sensor chip can determine the amplitude difference threshold corresponding to the current cycle based on the time interval between the current moment and the moment the ultrasonic signal was emitted. This amplitude difference threshold is used to determine whether the reference signal and the comparison signal are the target signal, reducing the possibility of misjudgment. Furthermore, the phase angle of the read reference signal and the comparison signal does not affect the judgment result, thereby improving the accuracy of the target echo signal.

[0089] Similarly, a corresponding timer can be omitted; that is, multiple amplitude difference thresholds can be pre-stored. These amplitude difference thresholds are time-dependent, as described above. However, the storage module only stores amplitude difference threshold information. During comparison, as the clock changes, threshold information at different addresses in the storage module is read and input into the comparison module for comparison. This method saves hardware circuitry, simplifies data processing, and improves processing speed. In this case, determining the amplitude difference threshold corresponding to the current cycle includes reading one of the multiple amplitude difference thresholds according to the clock cycle.

[0090] In other words, multiple pre-set amplitude difference thresholds are stored in the storage module. These thresholds correspond to different clock cycles, allowing the sensor chip to directly read the threshold values ​​from the storage module as the clock cycle changes. The ultrasonic sensor chip can then obtain the corresponding amplitude difference threshold based on the current clock cycle to determine whether the reference signal and comparison signal are the target signal.

[0091] In some embodiments, when the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals updated includes:

[0092] When the reference signal and the comparison signal are the target signals, the preset reading frequency is updated to the first frequency, the number of target signals is updated, and the reference signal and the comparison signal are saved.

[0093] In other words, when the ultrasonic sensor chip determines that the currently read reference signal and comparison signal are the target signals, it can update the preset reading frequency to the first frequency, update the number of target signals, and save the read reference signal and comparison signal so that the ultrasonic signal that matches the target echo signal can be fitted from the read reference signal and comparison signal in the future.

[0094] In some embodiments, when the reference signal and the comparison signal are target signals, the preset read frequency is updated to a first frequency, and the number of target signals updated includes:

[0095] When the reference signal and the comparison signal are target signals, the preset reading frequency is updated to the first frequency, the number of target signals is updated, and the reference signal and the comparison signal are deleted.

[0096] In other words, in order to reduce memory usage, after the ultrasonic sensor chip determines that the reference signal and the comparison signal are the target signals, updates the preset reading frequency to the first frequency, and updates the number of target signals, it can directly discard the read reference signal and comparison signal. That is, delete the read reference signal and comparison signal, and do not save the read reference signal and comparison signal, only record the number of target signals. This can greatly reduce memory usage and reduce hardware overhead.

[0097] As one possible implementation, the first frequency is half a wave period of the ultrasonic excitation signal (or target echo signal). Since the target echo signal required by the ultrasonic sensor chip is actually the ultrasonic signal reflected from the obstacle by the corresponding ultrasonic transmitting sensor, the wave period of the target echo signal is the same as the wave period of the ultrasonic signal emitted by its corresponding ultrasonic transmitting sensor. That is, the wave period of the target echo signal can be known in advance. Therefore, when the reference signal and comparison signal are the target signal, to improve the accuracy of the judgment result, the number of reads can be increased, i.e., the read cycle can be reduced by adjusting the read cycle to half a wave period. In this way, the reference signal and comparison signal can be read once every half wave period, and the corresponding target signal judgment can be performed.

[0098] In some embodiments, the first frequency can also be other times. For example, to further simplify the circuitry within the ultrasonic sensor chip and reduce the amount of data read, the first frequency can be set to one wave cycle of the ultrasonic signal. This allows for the reading of a reference signal and a comparison signal once per wave cycle, and the determination of whether the read reference signal and comparison signal are the target signal. Of course, the first frequency can also be set to other times, such as a quarter wave cycle of the ultrasonic signal, and this application does not limit this.

[0099] Since the first frequency is not less than the second frequency, it is greater than or equal to the second frequency. When the first frequency is greater than the second frequency, the ultrasonic sensor chip can update the preset reading interval to the first frequency when it determines that the reference signal and comparison signal read in the current cycle are the target signal, and update the preset reading interval to the second frequency when it determines that the reference signal and comparison signal read in the current cycle are not the target signal. In this way, when the ultrasonic sensor chip determines that the reference signal and comparison signal read in the current cycle are the target signal, it can read at the first frequency, thereby shortening the reading cycle and increasing the number of readings. When it determines that the reference signal and comparison signal read in the current cycle are not the target signal, it can read at the second frequency, avoiding unnecessary readings, reducing the number of readings, thereby reducing memory space usage and hardware overhead.

[0100] As one possible implementation, the first frequency is twice the second frequency.

[0101] As one possible implementation, the second frequency is the wave period of the ultrasonic signal.

[0102] Step S303: Determine whether a target echo signal has appeared based on whether the number of target signals is greater than a preset value.

[0103] In this embodiment of the application, after the ultrasonic sensor chip updates the number of target signals in the above steps, it can determine whether the read reference signal and comparison signal are target echo signals based on the number of target signals.

[0104] In some embodiments, a threshold for the number of reference signals and comparison signals read that are target signals can be preset. Thus, determining whether the reference signals and comparison signals read are target echo signals based on the number of target signals includes: when the number of target signals reaches a preset value, the reference signals and comparison signals read are determined to be target echo signals.

[0105] In other words, in order to more accurately determine whether the read ultrasonic signal is the target echo signal required by the ultrasonic sensor chip, a threshold number of reference signals and comparison signals that are target signals can be preset. In this way, after the ultrasonic sensor chip updates the number of target signals in the above steps, it can compare the number of recorded target signals with the preset value. When the number of target signals is equal to or greater than the preset value, it means that the number of reference signals and comparison signals that are target signals has reached the preset threshold. At this time, it can be determined that the read reference signals and comparison signals are target echo signals.

[0106] Furthermore, if the number of target signals does not reach the preset threshold, it indicates that the number of reference signals and comparison signals read is small. At this time, steps S301-S303 can be re-executed until the number of target signals reaches the preset threshold, and the read reference signals and comparison signals are determined as target echo signals.

[0107] In this embodiment, by periodically reading the reference signal and comparison signal to determine the echo signal, it is not necessary to wait for the reflected signal to be completely received before determining the echo signal, which can greatly reduce the amount of data read and reduce hardware overhead. Furthermore, it is not necessary to wait for the entire transmitted signal to be received or for the peak value to be extracted before performing the corresponding threshold determination, thus improving the processing speed of echo determination and thereby improving the efficiency of echo detection.

[0108] For example, after the ultrasonic transmitting sensor emits an ultrasonic signal a, it is reflected by an obstacle, and the ultrasonic receiving sensor can receive the ultrasonic signal b, which is then sent as an echo signal to the ultrasonic sensor chip. Figure 5As shown, the ultrasonic signal b is a sine wave with a period of T. The ultrasonic sensor chip reads the ultrasonic signal b according to a preset reading frequency. Assume a reference signal is read at time t1 and a comparison signal is read at time t2. Here, the preset reference value is 0 volts. If the amplitude of the reference signal read at time t1 in the current period is 0 volts, and the amplitude of the comparison signal is V1 volts, the ultrasonic sensor chip detects whether the amplitude of the reference signal is the preset reference value. When the amplitude of the reference signal read at time t1 in the current period is 0 volts, the ultrasonic sensor chip determines that the amplitude information of the reference signal is the preset reference value. At this time, the ultrasonic sensor chip can determine the threshold corresponding to the current period as the amplitude threshold. The ultrasonic sensor chip can then read the time of ultrasonic signal transmission from the timer and determine the amplitude threshold corresponding to the current period as Vth1 based on the time interval between the current time and the time of ultrasonic signal transmission (or, without a timer, the amplitude threshold can be read based on the clock cycle). The ultrasonic sensor chip compares the amplitude V1 of the comparison signal read in the current period with the amplitude threshold Vth1 corresponding to the current period. When the amplitude V1 of the comparison signal is greater than the amplitude threshold Vth1 corresponding to the current period, the reference signal and comparison signal read in the current period are determined as the target signal, and the number of target signals is incremented by 1 to update the number of target signals. Furthermore, the ultrasonic sensor chip can update the preset reading frequency to a first frequency, assuming the first frequency is half a wave cycle of the ultrasonic signal a. At this time, when the ultrasonic sensor chip reads the reference signal and comparison signal for the next time, it reads at a time interval of half a wave cycle. That is, the time interval between the next reading of the reference signal and comparison signal and the current reading of the reference signal and comparison signal is half a wave cycle. That is, the reference signal and comparison signal for the next period, i.e., t3 is the reference signal for the next period, t4 is the comparison signal for the next period, and the voltage corresponding to t4 is V4, as shown in the example. Figure 6a As shown.

[0109] The ultrasonic sensor chip detects whether the number of target signals reaches a preset threshold. If the number of target signals reaches the preset threshold, the acquired reference signal and comparison signal are determined to be the target echo signal. That is, since the currently read reference signal and comparison signal are both ultrasonic signal b, ultrasonic signal b can be directly determined to be the target echo signal. If the number of target signals detected by the ultrasonic sensor chip does not reach the preset threshold, the reference signal and comparison signal are read again according to the preset reading frequency. At this time, since the preset reading frequency is updated to the first frequency, the ultrasonic sensor chip must read the reference signal at the first frequency the next time. Similarly, the comparison signal must also be read at the first frequency the next time.

[0110] Alternatively, when the amplitude V1 of the comparison signal is less than the amplitude threshold Vth1 corresponding to the current cycle, the ultrasonic sensor chip determines that the reference signal and comparison signal read in the current cycle are not the target signal. At this time, the ultrasonic sensor chip resets the number of target signals to zero. The ultrasonic sensor chip can update the preset reading frequency to a second frequency. Assume the second frequency is one wave cycle of the ultrasonic signal a. Then, when the ultrasonic sensor chip reads the reference signal and comparison signal for the next time, it reads at a time interval of one wave cycle. That is, the time interval between the next reading of the reference signal and comparison signal and the current reading of the reference signal and comparison signal is one wave cycle. In other words, the reference signal and comparison signal for the next cycle are t3 (reference t3), t4 (comparison t4), and the voltage corresponding to t4 is V4. (See reference t4 for details.) Figure 6b As shown.

[0111] Alternatively, if the amplitude of the reference signal read at time t1 in the current cycle is V2 volts, and the amplitude of the comparison signal is V1 volts, when the ultrasonic sensor chip detects whether the amplitude of the reference signal is a preset reference value, since the amplitude of the reference signal read at time t1 in the current cycle is V2 volts, which is not 0 volts, the ultrasonic sensor chip determines that the amplitude information of the reference signal is not a preset reference value. In this case, the ultrasonic sensor chip can determine that the threshold corresponding to the current cycle is the amplitude difference threshold. The ultrasonic sensor chip can read the time of ultrasonic signal transmission from the timer, and determine the amplitude difference threshold corresponding to the current cycle as K1 based on the time interval between the current time and the time of ultrasonic signal transmission (or, without a timer, the amplitude difference threshold can be read based on the clock cycle). The ultrasonic sensor chip can calculate the amplitude difference between the reference signal and the comparison signal based on the amplitude information V2 volts of the reference signal and V1 volts of the comparison signal read in the current cycle, and then determine whether the reference signal and the comparison signal are the target signal based on the amplitude difference and the amplitude difference threshold. In this example, to more accurately compare the amplitude difference and the amplitude difference threshold, the amplitude difference angle can be used for comparison. That is, the ultrasonic sensor chip can refer to the amplitude information V2V of the reference signal, the amplitude information V1V of the comparison signal, the reading time t1 of the reference signal, and the reading time t2 of the comparison signal, based on the amplitude information V2V of the reference signal read in the current cycle. Figure 7aAs shown, the angle between the amplitude difference between the reference signal and the comparison signal is calculated. For example, the angle between the amplitude difference between the reference signal and the comparison signal can be calculated using the formula tanθ=(V0-V0') / L. Here, tanθ represents the angle between the amplitude difference between the reference signal and the comparison signal, V0 represents the amplitude information of the comparison signal, V0' represents the amplitude information of the reference signal, and L represents the time interval between the reference signal and the comparison signal. In this case, the ultrasonic sensor can calculate the angle between the amplitude difference between the reference signal and the comparison signal as tanθ=(V1-V2) / (t2-t1). After calculating the angle between the amplitude difference between the reference signal and the comparison signal read in the current cycle, the amplitude difference threshold K1 corresponding to the current cycle obtained by the ultrasonic sensor is the amplitude difference angle threshold. The ultrasonic sensor compares the angle between the amplitude difference between the reference signal and the comparison signal with the amplitude difference angle threshold. When the angle between the amplitude difference between the reference signal and the comparison signal is greater than the threshold value, the reference signal and the comparison signal are identified as target signals, and the number of target signals is incremented by 1 to update the target signal count. Furthermore, the ultrasonic sensor chip can update the preset reading frequency to a first frequency, assuming the first frequency is half a wave cycle of the ultrasonic signal a. At this time, when the ultrasonic sensor chip reads the reference signal and comparison signal for the next time, it does so at a time interval of half a wave cycle. That is, the time interval between the next reading of the reference signal and the current reading of the reference signal and the comparison signal is half a wave cycle. In other words, the reference signal and comparison signal for the next cycle are t3 (reference t3), t4 (comparison t4), and the voltage corresponding to t3 is V3, and the voltage corresponding to t4 is V4. Figure 7a As shown.

[0112] The ultrasonic sensor chip detects whether the number of target signals reaches a preset threshold. If the number of target signals reaches the preset threshold, the acquired reference signal and comparison signal are determined to be the target echo signal. That is, since the currently read reference signal and comparison signal are both ultrasonic signal b, ultrasonic signal b can be directly determined to be the target echo signal. If the number of target signals detected by the ultrasonic sensor chip does not reach the preset value, the reference signal and comparison signal are read again according to the preset reading frequency. At this time, since the preset reading frequency is updated to the first frequency, the ultrasonic sensor chip must read the reference signal at the first frequency the next time. Similarly, the comparison signal must also be read at the first frequency the next time.

[0113] Alternatively, when the amplitude difference between the reference signal and the comparison signal is less than the amplitude difference threshold (or the angle between the amplitude differences is less than the amplitude difference angle threshold), the ultrasonic sensor chip determines that the reference signal and comparison signal read in the current cycle are not the target signal. In this case, the ultrasonic sensor chip resets the number of target signals to zero. The ultrasonic sensor chip can update the preset reading frequency to a second frequency. Assume the second frequency is one wave cycle of the ultrasonic signal a. Then, when the ultrasonic sensor chip reads the reference signal and comparison signal for the next time, it reads at a time interval of one wave cycle. That is, the time interval between the next reading of the reference signal and comparison signal and the current reading of the reference signal and comparison signal is one wave cycle. For example, t3 is the reference signal for the next cycle, t4 is the comparison signal for the next cycle, the voltage corresponding to t3 is V3, and the voltage corresponding to t4 is V4. (Refer to...) Figure 7b As shown.

[0114] In this way, by reading and comparing ultrasonic signals in the above manner, if it is determined that the read reference signal and comparison signal are not the target signal, i.e., they do not meet the requirements of the target echo signal, the read reference signal and comparison signal are discarded, and no further reading or processing of reference signal and comparison signal is performed in this cycle, or the read reference signal and comparison signal are discarded. When it is determined that the read reference signal and comparison signal are the target signal, i.e., they meet the requirements of the target echo signal, the read reference signal and comparison signal can be saved, and the next reading of reference signal and comparison signal is performed at a first frequency, checking whether the read reference signal and comparison signal are the target signal. When the next reference signal and comparison signal are the target signal, the read reference signal and comparison signal can continue to be saved, until the number of collected reference signal and comparison signal that are target signals reaches a preset value, then the collected reference signal and comparison signal can be determined as the target echo signal, and the subsequent calculation of obstacle distance can continue. The method for determining the target echo signal in this embodiment significantly reduces the amount of ultrasonic signal data read, lowers hardware overhead, and discards unsuitable reference and comparison signals without consuming additional memory or cache space. Furthermore, this embodiment eliminates the need to wait for the ultrasonic receiving sensor to transmit all received ultrasonic waves or extract peak values ​​before determining if it is a target echo signal, improving the speed of target echo signal determination and echo detection efficiency. Moreover, this embodiment eliminates the need to set the reading point at a comparison threshold or peak value, allowing for more flexible setting of the reading time and period, thus improving the flexibility of echo detection.

[0115] exist Figures 6a-7bIn this process, signals that do not meet the requirements but appear before the target signal that meets the requirements are read using the second frequency.

[0116] It should be noted that when reading data using the first frequency, if the first frequency is twice the excitation signal frequency, then within one waveform period, two target signals that meet the requirements will appear. Therefore, when determining whether a target echo signal appears based on whether the number of target signals is greater than a preset value, the corresponding number should also be twice the waveform. For example, if five target signals that meet the requirements appear, then ten comparison results that meet the requirements will appear.

[0117] See Figure 8 This is a schematic diagram of the structure of an ultrasonic sensor chip provided in an embodiment of this application. Figure 8 As shown, the ultrasonic sensor chip includes: a sampling circuit 801, a filtering circuit 802, and a reading and processing circuit 803.

[0118] The sampling circuit 801 is coupled to the ultrasonic transducer to sample the echo signal.

[0119] The filter circuit 802 is electrically connected to the sampling circuit 801 and is used to filter the echo signal input to the sampling circuit 801 to output an echo signal of a preset frequency.

[0120] The reading processing circuit 803 is electrically connected to the filtering circuit 802 and is used to determine whether the input echo signal of the preset frequency is the target echo signal.

[0121] Among them, such as Figure 9a As shown, the read processing circuit 803 includes a read module 8031, a comparison module 8032, a control module 8033, and a judgment module 8034.

[0122] The reading module 8031 ​​is electrically connected to the filter circuit 802 and is used to periodically read the first point signal and the second point signal of the echo signal at a preset frequency according to the preset reading frequency.

[0123] The first signal is used as the reference signal, the second signal is used as the comparison signal, and the reading time interval between the reference signal and the comparison signal is preset.

[0124] The comparison module 8032 is electrically connected to the reading module 8031 ​​and is used to receive the amplitude information of the reference signal and the comparison signal input by the reading module 8031, and to determine whether the reference signal and the comparison signal are the target signal.

[0125] The control module 8033 is electrically connected to the comparison module 8032 and the reading module 8031. It is used to receive the comparison result of the comparison module 8031. When the reference signal and the comparison signal are target signals, the preset reading frequency of the reading module 8031 ​​is updated to the first frequency, and the number of target signals is updated. When the reference signal and the comparison signal are not target signals, the preset reading frequency of the reading module 8031 ​​is updated to the second frequency, and the number of target signals is restored to or maintained at the initial value, such as being cleared to zero.

[0126] The first frequency is not less than the second frequency.

[0127] The judgment module 8034 is electrically connected to the control module 8033 and is used to read the quantity data of the target signal from the control module 8033. If the quantity of the target signal is greater than a preset value, it is determined that a target echo signal has appeared.

[0128] As one possible implementation, the aforementioned ultrasonic sensor chip, such as Figure 9b As shown, it also includes: storage module 804.

[0129] Storage module 804 is used to store multiple threshold data.

[0130] The comparison module 8032 is also electrically connected to the storage module 804. Specifically, the comparison module 8032 is used to read threshold data to determine whether the reference signal and the comparison signal are the target signal.

[0131] As one possible implementation, the comparison module 8032: if the amplitude information of the reference signal is a preset reference value, then read the threshold data corresponding to the current period in the storage module 804, the threshold data being the amplitude threshold; compare whether the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period; if the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period, then determine the reference signal and the comparison signal as the target signal, and output the comparison result.

[0132] As one possible implementation, the comparison module 8032 is specifically used to: determine the moment when the ultrasonic signal is emitted, and determine the amplitude threshold corresponding to the current period based on the time interval between the current moment and the moment when the ultrasonic signal is emitted.

[0133] Alternatively, one of several amplitude thresholds can be read based on the clock cycle.

[0134] Alternatively, as a possible implementation, the comparison module 8032 is specifically used to: if the amplitude information of the reference signal is not a preset reference value, read the threshold data corresponding to the current period in the storage module 804, the threshold data being the amplitude difference threshold, and determine the amplitude difference between the reference signal and the comparison signal based on the amplitude information of the reference signal and the amplitude information of the comparison signal; compare whether the amplitude difference is not less than the amplitude difference threshold; when the amplitude difference is not less than the amplitude difference threshold, determine the reference signal and the comparison signal as the target signal, and output the comparison result.

[0135] As one possible implementation, the comparison module 8032 is specifically used to: determine the moment when the ultrasonic drive signal is emitted, and determine the amplitude difference threshold corresponding to the current period based on the time interval between the current moment and the moment when the ultrasonic drive signal is emitted. Alternatively, it can read one of multiple amplitude difference thresholds based on the clock period.

[0136] As one possible implementation, the first frequency is twice the second frequency.

[0137] As one possible implementation, the control module 8033 is specifically used to update the preset reading frequency of the reading module 8031 ​​to the first frequency and update the number of target signals when the reference signal and the comparison signal are target signals, and delete the reference signal and the comparison signal.

[0138] Corresponding to the above embodiments, this application also provides an automotive ultrasonic radar device. Figure 10 This is a schematic diagram of a car ultrasonic radar device according to an embodiment of the present invention. The car ultrasonic radar device includes an ultrasonic transducer 1001 and an ultrasonic sensor chip 1002. The ultrasonic sensor chip 1002 is the ultrasonic sensor chip described in the above embodiment.

[0139] The ultrasonic sensor chip 1002 is electrically connected to the ultrasonic transducer 1001 and is used to determine whether the echo signal received by the ultrasonic transducer 1001 is the target echo signal.

[0140] As one possible implementation, the aforementioned automotive ultrasonic radar device, such as Figure 11 As shown, it also includes: microprocessor chip 1003.

[0141] The microprocessor chip 1003 is electrically connected to the ultrasonic sensor chip 1002 and is used to send a trigger signal to the ultrasonic sensor chip 1002 and receive an indication signal of the target echo signal sent by the ultrasonic sensor chip 1002.

[0142] The ultrasonic sensor chip 1002 is also used to receive the trigger signal sent by the microprocessor chip 1003 and generate a drive signal to drive the ultrasonic transducer 1001 to emit ultrasonic waves according to the trigger signal. When it is determined that the echo signal received by the ultrasonic transducer 1001 is the target echo signal, it sends an indication signal of the target echo signal to the microprocessor chip 1003.

[0143] Microprocessor chips, commonly referred to as ECUs or domain controllers in automobiles, can be miniature central control chips or system-on-a-chips, such as MCUs, DSPs, MPUs, or micro CPUs, capable of processing digital and analog signals, or performing signal control, instruction processing, and computation functions.

[0144] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions in the embodiments of the present invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or certain parts of the embodiments of the present invention.

[0145] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. A method for detecting echo signals from an ultrasonic sensor, characterized in that, include: The first and second point signals of the echo signal are periodically read according to a preset reading frequency. The first point signal is used as a reference signal and the second point signal is used as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time. Based on the amplitude information of the reference signal and the comparison signal, it is determined whether the reference signal and the comparison signal are target signals; when the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals is updated; when the reference signal and the comparison signal are not target signals, the preset reading frequency is updated to a second frequency, and the number of target signals is restored to or maintained at the initial value. The first frequency is not less than the second frequency; Whether a target echo signal appears is determined based on whether the number of target signals is greater than a preset value.

2. The method according to claim 1, characterized in that, The first frequency is twice the second frequency.

3. The method according to claim 1, characterized in that, Determining whether the reference signal and the comparison signal are target signals based on the amplitude information of the reference signal and the comparison signal includes: Detect whether the amplitude information of the reference signal is a preset reference value; If the amplitude information of the reference signal is a preset reference value, then the amplitude threshold corresponding to the current period is determined; Detect whether the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period; If the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period, then the reference signal and the comparison signal are determined to be the target signal.

4. The method according to claim 3, characterized in that, The determination of the amplitude threshold corresponding to the current period includes: Determine the moment when the ultrasonic drive signal is emitted, and based on the time interval between the current moment and the moment when the ultrasonic drive signal is emitted, determine the amplitude threshold corresponding to the current period.

5. The method according to claim 3, characterized in that, The determination of the amplitude threshold corresponding to the current period includes: Read one of multiple amplitude thresholds based on the clock cycle.

6. The method according to claim 3, characterized in that, Also includes: If the amplitude information of the reference signal is not a preset reference value, then the amplitude difference threshold corresponding to the current period is determined, and the amplitude difference between the reference signal and the comparison signal is determined based on the amplitude information of the reference signal and the amplitude information of the comparison signal. Detect whether the amplitude difference is not less than the amplitude difference threshold; When the amplitude difference is not less than the amplitude difference threshold, the reference signal and the comparison signal are determined to be the target signal.

7. The method according to claim 6, characterized in that, The step of determining the amplitude difference threshold corresponding to the current period includes: Determine the moment when the ultrasonic drive signal is emitted, and based on the time interval between the current moment and the moment when the ultrasonic drive signal is emitted, determine the amplitude difference threshold corresponding to the current period.

8. The method according to claim 6, characterized in that, The step of determining the amplitude difference threshold corresponding to the current period includes: Read one of multiple amplitude difference thresholds based on the clock cycle.

9. The method according to any one of claims 1-8, characterized in that, When the reference signal and the comparison signal are target signals, the preset reading frequency is updated to a first frequency, and the number of target signals updated includes: When the reference signal and the comparison signal are target signals, the preset reading frequency is updated to the first frequency, the number of target signals is updated, and the reference signal and the comparison signal are deleted.

10. An ultrasonic sensor chip, characterized in that, Includes sampling circuit, filtering circuit, and readout processing circuit; The sampling circuit is coupled to the ultrasonic transducer to sample the echo signal; The filtering circuit is electrically connected to the sampling circuit and is used to filter the echo signal input to the sampling circuit to output an echo signal of a preset frequency. The reading processing circuit is electrically connected to the filtering circuit and is used to determine whether the input echo signal of the preset frequency is the target echo signal. The reading processing circuit includes a reading module, a comparison module, a control module, and a judgment module. The reading module is electrically connected to the filtering circuit and is used to periodically read the first point signal and the second point signal of the echo signal at the preset frequency according to the preset reading frequency. The first point signal is used as a reference signal and the second point signal is used as a comparison signal. The reading time interval between the reference signal and the comparison signal is a preset time. The comparison module is electrically connected to the reading module and is used to receive the amplitude information of the reference signal and the comparison signal input by the reading module, and to determine whether the reference signal and the comparison signal are target signals; The control module, electrically connected to the comparison module and the reading module, is used to receive the comparison result from the comparison module. When the reference signal and the comparison signal are target signals, the preset reading frequency of the reading module is updated to a first frequency, and the number of target signals is updated. When the reference signal and the comparison signal are not target signals, the preset reading frequency of the reading module is updated to a second frequency, and the number of target signals is restored to or maintained at its initial value. The first frequency is not less than the second frequency. The judgment module is electrically connected to the control module and is used to read the number of target signals from the control module. If the number of target signals is greater than a preset value, it is determined that a target echo signal has appeared.

11. The chip according to claim 10, characterized in that, It also includes a storage module. The storage module is used to store multiple threshold data; The comparison module is also electrically connected to the storage module to read the threshold data for determining whether the reference signal and the comparison signal are target signals.

12. The chip according to claim 11, characterized in that, The comparison module is specifically used for: if the amplitude information of the reference signal is a preset reference value, then reading the threshold data corresponding to the current period in the storage module, wherein the threshold data is an amplitude threshold; comparing whether the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period; if the amplitude information of the comparison signal is not less than the amplitude threshold corresponding to the current period, then determining that the reference signal and the comparison signal are target signals, and outputting the comparison result.

13. The chip according to claim 11, characterized in that, The comparison module is specifically used for: if the amplitude information of the reference signal is not a preset reference value, then reading the threshold data corresponding to the current period in the storage module, the threshold data being an amplitude difference threshold, and determining the amplitude difference between the reference signal and the comparison signal based on the amplitude information of the reference signal and the amplitude information of the comparison signal; comparing whether the amplitude difference is not less than the amplitude difference threshold. When the amplitude difference is not less than the amplitude difference threshold, the reference signal and the comparison signal are determined as the target signal, and the comparison result is output.

14. The chip according to any one of claims 10-13, characterized in that, The first frequency is twice the second frequency.

15. An automotive ultrasonic radar device, characterized in that, Includes an ultrasonic transducer and an ultrasonic sensor chip as described in any one of claims 10-14; The ultrasonic sensor chip is electrically connected to the ultrasonic transducer and is used to determine whether the echo signal received by the ultrasonic transducer is the target echo signal.

16. The automotive ultrasonic radar device according to claim 15, characterized in that, Also includes: Microprocessor chip; The microprocessor chip is electrically connected to the ultrasonic sensor chip and is used to send a trigger signal to the ultrasonic sensor chip and receive an indication signal of the target echo signal sent by the ultrasonic sensor chip. The ultrasonic sensor chip is also configured to receive a trigger signal sent by the microprocessor chip and generate a drive signal to drive the ultrasonic transducer to emit ultrasonic waves according to the trigger signal, and when it is determined that the echo signal received by the ultrasonic transducer is the target echo signal, send an indication signal of the target echo signal to the microprocessor chip.

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