Ultrasonic ranging method, circuit, chip and system

Abstract

This application provides an ultrasonic ranging method, circuit, chip, and system, relating to the field of data processing. The method includes: performing amplitude modulation processing on a first signal according to a first amplitude modulation function to obtain a second signal, where the first amplitude modulation function is a time-varying function; adjusting the gain of the second signal according to a first gain adjustment function, and transmitting a first ultrasonic wave based on the gain-adjusted second signal; determining a third signal based on the received second ultrasonic wave, where the second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave; adjusting the gain of the third signal according to a second gain adjustment function to obtain a fourth signal; and determining distance information based on the fourth signal. The method provided in this application improves the accuracy and anti-interference capability of ultrasonic ranging.

Description

Technical Field

[0001] This application relates to the field of data processing, and in particular to an ultrasonic ranging method, circuit, chip, and system. Background Technology

[0002] Ultrasonic ranging technology is widely used in fields such as car parking assistance systems, automatic obstacle avoidance systems, and home smart devices (such as robot vacuum cleaners) due to its advantages such as low cost, high real-time performance, and simple structure.

[0003] For example, in the automotive field, ultrasonic sensors can emit high-frequency sound waves and receive reflected echoes, calculate the target distance based on the round-trip time of the sound waves, and provide drivers with accurate obstacle distance information, thereby assisting in parking or avoiding collision risks.

[0004] However, in the above implementation methods, the surrounding environment of the vehicle is complex and changeable, and there is a lot of signal interference, resulting in poor accuracy and anti-interference ability of ultrasonic ranging. Summary of the Invention

[0005] This application provides an ultrasonic ranging method, circuit, chip, and system to solve the technical problems of poor accuracy and anti-interference ability in ultrasonic ranging.

[0006] In a first aspect, this application provides an ultrasonic ranging method, comprising: performing amplitude modulation processing on a first signal according to a first amplitude modulation function to obtain a second signal, wherein the first amplitude modulation function is a time-varying function; adjusting the gain of the second signal according to a first gain adjustment function, and transmitting a first ultrasonic wave based on the gain-adjusted second signal; determining a third signal based on the received second ultrasonic wave, wherein the second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave; adjusting the gain of the third signal according to a second gain adjustment function to obtain a fourth signal; and determining distance information based on the fourth signal.

[0007] In one possible implementation of the first aspect, the first amplitude modulation function is a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

[0008] In one possible implementation of the first aspect, gain adjustment of the third signal to obtain the fourth signal includes: gain adjustment of the third signal according to a second gain adjustment function to obtain the fourth signal, wherein the second gain adjustment function is a linear amplitude modulation function or a nonlinear amplitude modulation function.

[0009] In one possible implementation of the first aspect, the method further includes: generating a corresponding reference signal based on the first ultrasonic wave; and determining distance information based on the fourth signal, including: determining the distance information based on the fourth signal and the reference signal.

[0010] In one possible implementation of the first aspect, determining distance information based on a fourth signal and a reference signal includes: performing a correlation operation on the fourth signal and the reference signal to generate a correlation output signal; and determining the distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave.

[0011] In one possible implementation of the first aspect, the first amplitude modulation function is at least one of a discrete step function, an exponential function, a logarithmic function, and a power function; or, the first amplitude modulation function is a combination function including at least two of the discrete step function, exponential function, logarithmic function, and power function.

[0012] Secondly, this application provides an ultrasonic signal processing circuit, which includes a driving circuit, a receiving circuit, and a processing circuit, wherein:

[0013] The output of the processing circuit is connected to the driving circuit, and the input of the processing circuit is connected to the receiving circuit.

[0014] The processing circuit is used to perform amplitude modulation processing on the first signal according to the first amplitude modulation function to obtain the second signal. The first amplitude modulation function is a time-varying function.

[0015] It is also used to adjust the gain of the second signal according to the first gain adjustment function, and to transmit the gain-adjusted second signal to the drive circuit;

[0016] It is also used to receive the third signal transmitted by the circuit, and to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, and to determine the distance information based on the fourth signal;

[0017] The driving circuit is used to receive the second signal sent by the processing circuit and to emit the first ultrasonic wave according to the second signal;

[0018] The receiving circuit is used to determine the third signal from the received second ultrasonic wave and transmit the third signal to the processing circuit. The second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave.

[0019] In one possible implementation of the second aspect, the first amplitude modulation function is a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

[0020] In one possible implementation of the second aspect, the processing circuit is used to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, wherein the second gain adjustment function is a linear gain adjustment function or a nonlinear gain adjustment function.

[0021] In one possible implementation of the second aspect, the processing circuit is further configured to generate a corresponding reference signal based on the first ultrasonic wave, and determine distance information based on the fourth signal and the reference signal.

[0022] In one possible implementation of the second aspect, the processing circuit is used to perform correlation operations on the fourth signal and the reference signal to generate a correlation output signal; and to determine the distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave.

[0023] In one possible implementation of the second aspect, the first amplitude modulation function is at least one of a discrete step function, an exponential function, a logarithmic function, and a power function; or, the first amplitude modulation function is a combination function including at least two of the discrete step function, exponential function, logarithmic function, and power function.

[0024] Thirdly, this application provides an ultrasonic signal processing chip, which may include the ultrasonic signal processing circuit in any implementation of the second aspect, and may be used to implement the method of any of the first aspects.

[0025] Fourthly, this application provides an ultrasonic ranging system, including an ultrasonic sensor, a processing device, and an ultrasonic signal processing chip, which can be used to implement the method of any of the first aspects.

[0026] The ultrasonic ranging method, circuit, chip, and system provided in this application improve the accuracy and anti-interference capability of ultrasonic ranging through dynamic amplitude modulation and dynamic gain compensation. Specifically, the transmitted signal through dynamic amplitude modulation can reduce the energy of the spectral sidelobes and reduce the risk of resonance with environmental noise (such as engine vibration and ultrasonic signals from other vehicles); through matched filtering and correlation processing, only the echo components that match the amplitude modulation characteristics are retained, suppressing mismatched interference. Furthermore, the transmitted signal is transmitted at low amplitude at short distances to avoid receiver saturation, and at high amplitude at long distances to enhance the echo signal strength; the dynamic gain control at the receiver compensates for signal attenuation, improving the signal-to-noise ratio of weak echoes at long distances. Moreover, the nonlinear amplitude modulation function (such as low amplitude transmission in the initial stage) ensures that the short-distance echo signal returns after the transmitted signal ends, avoiding signal superposition problems and effectively shortening the dead zone distance. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 This is a schematic diagram of a scenario for an ultrasonic ranging device provided in an embodiment of this application;

[0029] Figure 2A flowchart illustrating an ultrasonic ranging method provided in an embodiment of this application;

[0030] Figure 3 A schematic diagram of a scenario for an ultrasonic ranging method provided in an embodiment of this application;

[0031] Figure 4 A schematic diagram of a scenario for another ultrasonic ranging method provided in an embodiment of this application;

[0032] Figure 5 This is a schematic diagram of the structure of an ultrasonic signal processing circuit provided in an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of the structure of an ultrasonic signal processing chip provided in an embodiment of this application;

[0034] Figure 7 This is a schematic diagram of the structure of an ultrasonic ranging system provided in an embodiment of this application;

[0035] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application.

[0036] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0037] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] Figure 1 This is a schematic diagram of an ultrasonic ranging device according to an embodiment of this application. Figure 1 As shown, the ultrasonic ranging device 100 may include a transmitting module 101, a receiving module 102, and a processing module 103. The transmitting module 101 can be used to transmit ultrasonic waves according to the signal from the processing module 103, the receiving module 102 can be used to receive ultrasonic waves, and the processing module 103 can implement the ultrasonic ranging method provided in the embodiments of this application.

[0039] Ultrasonic ranging technology is widely used in fields such as car parking assistance systems, automatic obstacle avoidance systems, and home smart devices (such as robot vacuum cleaners) due to its advantages such as low cost, high real-time performance, and simple structure.

[0040] For example, in the automotive field, ultrasonic sensors can emit high-frequency sound waves and receive reflected echoes, calculate the target distance based on the round-trip time of the sound waves, and provide drivers with accurate obstacle distance information, thereby assisting in parking or avoiding collision risks.

[0041] However, in the above implementation methods, the surrounding environment of the vehicle is complex and changeable, and there is a lot of signal interference, resulting in poor accuracy and anti-interference ability of ultrasonic ranging.

[0042] Furthermore, when multiple sensors work together, crosstalk is easily generated if the emitted signals of each sensor have the same characteristics, further reducing the reliability of the system. Moreover, in short-range (0~10cm) detection, the excessively high emission intensity of traditional fixed-amplitude pulse signals can lead to signal saturation at the receiving end, while low-energy signals are difficult to cover distant targets, resulting in poor accuracy of ultrasonic ranging.

[0043] The ultrasonic ranging method, apparatus, equipment, storage medium, and program products provided in this application are intended to solve the above-mentioned technical problems of the prior art.

[0044] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0045] Figure 2 This is a flowchart illustrating an ultrasonic ranging method provided in an embodiment of this application, as shown below. Figure 2 As shown, the method includes:

[0046] S201. The ultrasonic ranging device performs amplitude modulation processing on the first signal according to the first amplitude modulation function to obtain the second signal.

[0047] When an ultrasonic ranging device needs to emit a first ultrasonic wave, it can first perform amplitude modulation processing on the first signal according to a first amplitude modulation function to obtain a second signal. The first amplitude modulation function is a time-varying function.

[0048] It is understandable that the first signal is a drive signal generated by the ultrasonic ranging device to control the ultrasonic waves. After generating the first signal (drive signal), the ultrasonic ranging device can further modulate the first signal according to a preset first amplitude modulation function to obtain the second signal. The second signal can be understood as a drive signal generated by the change of signal amplitude over time.

[0049] S202. The ultrasonic ranging device adjusts the gain of the second signal according to the first gain adjustment function, and emits the first ultrasonic wave based on the second signal after gain adjustment.

[0050] After obtaining the second signal that has undergone amplitude modulation processing, the ultrasonic ranging device can adjust the gain of the second signal according to the first gain adjustment function to obtain the gain-adjusted second signal. Then, the ultrasonic ranging device uses the gain-adjusted second signal as a driving signal to emit the corresponding first ultrasonic wave.

[0051] For example, the processing module of the ultrasonic ranging device may include a power amplifier, which can amplify the second signal according to a preset first gain adjustment function.

[0052] Understandably, the gain-adjusted second signal is also a drive signal undergoing amplitude modulation. The ultrasonic ranging device can use this gain-adjusted second signal as a drive signal to drive the ultrasonic transmitter and emit the corresponding first ultrasonic wave. Since the amplitude of the emitted first ultrasonic wave matches the gain-adjusted second signal, for example, the transmitting module of the ultrasonic ranging device may include an ultrasonic transducer. The ultrasonic ranging device can drive the ultrasonic transducer according to the gain-adjusted second signal to generate an ultrasonic pulse with gradually changing amplitude characteristics.

[0053] In this embodiment of the application, the time of emitting the first ultrasonic wave can be the timestamp corresponding to the second signal, the timestamp corresponding to the first signal, or the timestamp corresponding to the first ultrasonic wave emitted by the transmitting module of the ultrasonic ranging device. The specific time is not limited here.

[0054] S203. The ultrasonic ranging device determines the third signal based on the received second ultrasonic wave, where the second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave.

[0055] It is understandable that the first ultrasonic wave emitted by the ultrasonic ranging device will be reflected after encountering the target obstacle. The ultrasonic ranging device can receive the second ultrasonic wave and determine the third signal based on the received second ultrasonic wave, that is, the second ultrasonic wave is converted into the corresponding electrical signal.

[0056] For example, the receiving module of an ultrasonic ranging device may include an ultrasonic sensor that can receive a second ultrasonic wave and generate a corresponding third signal.

[0057] S204. The ultrasonic ranging device adjusts the gain of the third signal according to the second gain adjustment function to obtain the fourth signal.

[0058] After acquiring the third signal, the ultrasonic ranging device can adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal.

[0059] Understandably, after acquiring the third signal, the amplitude of the ultrasonic ranging device will decrease due to energy attenuation during the propagation of ultrasonic waves. Therefore, the ultrasonic ranging device can adjust the gain of the third signal to obtain the fourth signal, thereby compensating for the amplitude attenuation caused by ultrasonic wave attenuation.

[0060] For example, the processing module of the ultrasonic ranging device can adjust the gain of the third signal to obtain the fourth signal.

[0061] S205. Ultrasonic ranging devices determine distance information based on the fourth signal.

[0062] The ultrasonic ranging device determines distance information based on the fourth signal. It can be understood that the fourth signal is determined based on the second ultrasonic wave, which is the ultrasonic wave reflected from the first ultrasonic wave. Therefore, the distance information determined by the fourth signal is the distance information of the propagation of the first and second ultrasonic waves.

[0063] For example, the processing module of the ultrasonic ranging device can determine the distance information of ultrasonic wave propagation based on the time difference between the timestamp corresponding to the fourth signal (i.e., the time when the second ultrasonic wave is received) and the timestamp corresponding to the second signal (i.e., the time when the first ultrasonic wave is emitted) and the propagation speed of the ultrasonic wave.

[0064] Specifically, the total distance the ultrasonic wave travels is the product of the ultrasonic wave propagation time and the ultrasonic wave propagation speed; the distance between the target obstacle and the ultrasonic ranging device is half of the total distance the ultrasonic wave travels.

[0065] In this embodiment, the time when the second ultrasonic wave is received can be the timestamp corresponding to the fourth signal, or the timestamp corresponding to the third signal, or the timestamp corresponding to when the receiving module of the ultrasonic ranging device receives the second ultrasonic wave. The specific time is not limited here.

[0066] For example, such as Figure 3As shown, the transmitting module (i.e., the transmitter (TX)) of the ultrasonic ranging device emits a first ultrasonic wave towards the obstacle and starts timing simultaneously. The first ultrasonic wave propagates through the air, and upon encountering the obstacle, it immediately returns. The ultrasonic ranging device receives the reflected second ultrasonic wave and immediately stops timing. The speed of ultrasonic wave propagation in air is 340 meters per second. Based on the time t recorded by the timer, the distance L between the transmitting point (ultrasonic ranging device) and the obstacle can be calculated. For example, if the timer records t = 2 seconds, the corresponding ultrasonic distance is: 340 meters per second * 2 seconds = 680 meters. Therefore, the distance L between the ultrasonic ranging device and the obstacle is 680 / 2 = 340 meters.

[0067] This possible implementation addresses the insufficient anti-interference capability of fixed-amplitude single-frequency pulse signals in existing technologies by leveraging the amplitude variation characteristics of the amplitude-modulated (AM) drive signal. Specifically, by varying the amplitude of the AM drive signal over time, the spectral energy distribution of the transmitted signal becomes wider, with the main lobe energy concentrated within a specific time window. Compared to fixed-amplitude signals, AM signals exhibit reduced spectral sidelobe energy, minimizing resonance interference with environmental noise (such as engine vibration and signals from adjacent vehicles). Furthermore, the gradual change characteristic of AM signals enhances the main lobe energy after matched filtering, improving the signal-to-noise ratio of echo detection. For example, in car parking scenarios, AM signals can effectively avoid interference from engine vibration noise (50kHz~60kHz), preventing false triggering. Moreover, the nonlinear characteristics of AM signals result in extremely low cross-correlation between the transmitted signals of different vehicles, reducing crosstalk during multi-sensor collaborative operation. For instance, when multiple vehicles simultaneously use ultrasonic ranging, the frequency distribution differences in AM signals reduce interference from other vehicles' signals to the receiver of the receiving vehicle. In summary, the embodiments of this application can improve the anti-interference capability of ultrasonic ranging systems in complex noise environments, while enhancing the detectability of echo signals, providing fundamental support for short-range blind zone elimination and long-range target detection.

[0068] In some embodiments, the first amplitude modulation function is a time-varying function, which may be, for example, a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

[0069] For example, the first amplitude modulation function in the embodiments of this application can be a linear amplitude modulation function or a nonlinear amplitude modulation function. For example, it can be one of a discrete step function, an exponential function, a logarithmic function or a power function, or it can be a nonlinear amplitude modulation function that includes at least two of the discrete step function, exponential function, logarithmic function or power function. That is, the nonlinear amplitude modulation function can be a nonlinear amplitude modulation function obtained by combining at least two of the exponential function, logarithmic function or power function.

[0070] In this embodiment of the application, the first amplitude modulation function can be a linear amplitude modulation function, which means that the amplitude change of the modulation signal (i.e., the second signal) and the input control signal (the first signal) have a linear relationship (i.e., a linear relationship). If the input signal increases by a certain factor, the output amplitude will also increase by the same factor.

[0071] For example, the corresponding mathematical formula could be: N = k * M + b, where N is the amplitude of the second signal, M is the amplitude of the first signal, k is a preset coefficient, and b is a preset bias value.

[0072] The first amplitude modulation function can also be a nonlinear amplitude modulation function, that is, a function in which the input and output are not proportional and the graph is not a straight line. For example, it can be one of the discrete step function, exponential function, logarithmic function or power function, or it can be a combination function including at least two of the discrete step function, exponential function, logarithmic function or power function.

[0073] The first amplitude modulation function can also be a discrete step function, meaning that the amplitude of the output signal does not change continuously, but jumps to a preset fixed value according to the interval where the input signal is located.

[0074] For example, if the amplitude of the first input signal is less than the first threshold of 50, the amplitude of the corresponding second signal is 1; if the amplitude of the first input signal is greater than or equal to the first threshold of 50 and less than the second threshold of 100, the amplitude of the corresponding second signal is 2.5; if the amplitude of the first input signal is greater than or equal to the second threshold of 100, the amplitude of the corresponding second signal is 5.

[0075] The first amplitude modulation function can also be a combination of at least two of the following: discrete step function, exponential function, logarithmic function, or power function. For example, the corresponding mathematical formula could be: when 0 ≤ x ≤ 1, y = x, which is a linear function; when 1 < x, y = ln(x) + 1, which is a nonlinear function.

[0076] For example, in the step of generating the drive signal, the ultrasonic ranging device adjusts the amplitude variation curve of the transmitted signal by selecting a nonlinear amplitude modulation function in the form of a discrete step function, exponential, logarithmic, or power function. For instance, when an exponential function is selected, the amplitude of the transmitted signal increases slowly in the initial stage and then rises rapidly; when a logarithmic function is selected, the amplitude rises rapidly in the initial stage and then tends to level off; when a power function is selected, the rate of amplitude change is determined by the power exponent. The introduction of the nonlinear modulation function gives the envelope function of the transmitted signal a gradual change characteristic, reduces the energy of the spectral sidelobes, and enhances the energy of the main lobe of the matched filter.

[0077] Among them, the non-linear amplitude modulation function refers to an amplitude modulation function whose amplitude change does not conform to a linear relationship, and the linear amplitude modulation function refers to an amplitude modulation function whose amplitude change conforms to a linear relationship.

[0078] For example, as Figure 4 shown, in order to control the amplitude of the control signal to change with time during ultrasonic wave transmission, the ultrasonic ranging device can perform amplitude modulation processing on the first signal through the following amplitude modulation function:

[0079] A(t) = A0 + (A1 - A0) × (t / T)ⁿ, 0 ≤ t ≤ T;

[0080] Among them, the period of the pulse emission duration is T, A0 is the amplitude at the initial time t = 0, A1 is the amplitude at the end time t = T; the exponential factor n is the amplitude modulation index, which is used to control the non-linear degree of the amplitude change, and n is not 0.

[0081] In the case of n = 1, the first amplitude modulation function is a linear amplitude modulation function (linear envelope);

[0082] In the case of n > 1, the first amplitude modulation function is a non-linear amplitude modulation function, and the amplitude rises rapidly with time;

[0083] In the case of 0 < n < 1, the first amplitude modulation function is a non-linear amplitude modulation function, and the amplitude rises rapidly at the beginning and then flattens out.

[0084] As Figure 4 shown, the curve S1 is the change of the emission signal amplitude envelope A(t) with time when n = 0.5, and its initial rise is rapid and then flattens out later (suitable for early energy concentration); the straight line S2 is the change of the emission signal amplitude envelope A(t) with time when n = 1, and its change is linear and the energy is evenly distributed; the curves S3 and S4 are the changes of the emission signal amplitude envelope A(t) with time when n = 2 and n = 3, and their amplitudes start slowly and then rise rapidly later (suitable for enhancing the tail energy and suppressing the early sidelobes).

[0085] In this possible implementation, through the diverse selection of the amplitude modulation function, the spectral distribution of the emitted signal can more flexibly match the environmental noise characteristics. For example, in a high-noise scenario, the exponential function can quickly cover the noise frequency band and reduce resonance interference; in a low-noise scenario, the logarithmic function reduces energy waste and extends the system battery life. In addition, the gradual change characteristic of the non-linear modulation function further suppresses the energy of the spectral sidelobes and improves the signal-to-noise ratio of the main lobe of the matched filter, thereby enhancing the ranging stability in complex environments.

[0086] In some embodiments, the ultrasonic ranging device adjusts the gain of the third signal to obtain a fourth signal, which may specifically include:

[0087] The ultrasonic ranging device can adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal. The second gain adjustment function can be a linear gain adjustment function or a nonlinear gain adjustment function.

[0088] It is understandable that ultrasound will experience energy attenuation when it propagates in a medium, and the energy attenuates exponentially with distance (high-frequency signals attenuate even faster). Ultrasonic ranging devices can increase the gain linearly or non-linearly with time according to this time-varying gain, so that the amplification factor of the weak echo signal in the deep part is higher than that of the strong signal in the shallow part, thus compensating for the amplitude difference caused by attenuation.

[0089] For example, an ultrasonic ranging device can adjust the gain of a programmable gain amplifier (PGA) using a preset gain curve to achieve dynamic gain compensation. For instance, when using a linear gain curve, the gain increases uniformly over time; when using a nonlinear gain curve, the gain changes exponentially.

[0090] In this possible implementation, linear or nonlinear gain curves are used to make dynamic gain compensation more closely match the propagation characteristics of ultrasound (energy decays exponentially with distance), thereby improving the signal-to-noise ratio of weak echo signals. For example, in obstacle avoidance scenarios for industrial robots, nonlinear gain curves can more accurately compensate for signal attenuation over long distances, improving detection sensitivity.

[0091] In some embodiments, the ultrasonic ranging device may adjust the gain of the third signal according to the second gain adjustment function to obtain a fourth signal, the amplitude range of which does not exceed a preset range, for example, the amplitude range of which does not exceed the sampling range of the ADC of the ultrasonic ranging device.

[0092] For example, after receiving the echo signal of the third signal, the system adjusts the PGA gain according to a preset gain curve to dynamically compensate for the echo signal. For instance, the gain curve is designed as an exponential function so that the amplification factor of a weak signal at a distance is higher than that of a strong signal at a close distance.

[0093] Understandably, to avoid near-field saturation, ultrasonic ranging devices can reduce ultrasonic transmission power during short-range measurements. Simultaneously, ultrasonic ranging devices can perform dynamic gain control to ensure that the near-range echo is not clipped (i.e., does not exceed the analog-to-digital converter (ADC) range). The unsaturated echo signal can be sampled with high precision by the ADC, and then processed by the DSP (digital signal processor) through digital filtering (such as FIR denoising) and time extraction (cross-correlation algorithms).

[0094] In this possible implementation, dynamic gain compensation is used to amplify weak signals at long distances more than strong signals at close distances. This avoids receiver saturation, shortens dead zone distance, and improves the detectability of distant targets. For example, in a logistics sorting robot scenario, the gain is lower for close-range detection, and the signal is not saturated; the gain is higher for long-range detection, and weak echo signals are preserved.

[0095] Dead zone distance refers to the closest distance that an ultrasonic ranging device cannot effectively measure. When the ranging distance is short, because the initial wave intensity is low, the echo signal has not yet overflowed after being amplified by the receiver (receive, RX). It can be converted by the ADC and processed by the DSP, which can effectively shorten the dead zone distance.

[0096] In some embodiments, the method further includes:

[0097] S206. The ultrasonic ranging device generates a corresponding reference signal based on the first ultrasonic wave.

[0098] For example, after generating the second signal as the amplitude modulation drive signal, the ultrasonic ranging device can simultaneously record a copy of its waveform and store it as a reference signal. For instance, the processing circuit can sample and store the digital waveform via an ADC when the drive signal is generated, for use in subsequent echo signal correlation processing.

[0099] Here, the waveform copy refers to a complete waveform record of the amplitude modulation drive signal, used for subsequent processing of the echo signal. For example, the digital waveform of the transmitted signal can be stored in a memory.

[0100] The reference signal refers to the reference signal used for matched filtering, which is correlated with the echo signal. For example, a digital copy of the transmitted signal is stored using a DSP.

[0101] Correspondingly, the ultrasonic ranging device determines the distance information based on the fourth signal, which may specifically include:

[0102] Ultrasonic ranging devices determine distance information based on a fourth signal and a reference signal.

[0103] For example, an ultrasonic ranging device can determine the propagation time of the ultrasonic wave based on the time difference between the fourth signal and the reference signal, and then determine the corresponding distance information based on the propagation time and the speed of ultrasonic wave propagation.

[0104] In this possible implementation, by recording a waveform copy of the amplitude modulation drive signal, the correlation processing of the echo signal can be precisely matched to the characteristics of the transmitted signal, thereby suppressing unmatched interference signals. For example, when multiple vehicles use ultrasonic ranging simultaneously, the matching of the reference signal can distinguish the signals of one's own vehicle from those of other vehicles, reducing crosstalk misjudgments.

[0105] In some embodiments, the ultrasonic ranging device determines distance information based on a fourth signal and a reference signal, which may specifically include:

[0106] The ultrasonic ranging device performs correlation calculations based on the fourth signal and the reference signal to generate a correlation output signal; then, it determines the distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave.

[0107] For example, after receiving the echo signal, the ultrasonic ranging device can perform correlation operations between it and a reference signal. For instance, a DSP can perform a sliding window correlation between the echo signal and a stored reference signal to extract the peak time.

[0108] The correlation operation refers to cross-correlation processing of the echo signal and the reference signal to extract the matching component. For example, a sliding window correlation algorithm can be executed by a DSP.

[0109] The related output signal refers to the signal output after correlation operation, which contains information about the peak time. For example, the peak signal generated by matched filtering.

[0110] The peak moment refers to the moment when the energy in the relevant output signal is most concentrated, corresponding to the sound wave's time of flight. For example, the peak position can be determined using a peak detection algorithm.

[0111] For example, the first ultrasonic wave is emitted at "0 seconds" (the "emission moment"). A copy of the amplitude modulation drive signal waveform is recorded as a reference signal. Then, the second ultrasonic wave, reflected back after the first ultrasonic wave hits an obstacle, is received by the receiver of the ultrasonic ranging device, thus obtaining the fourth signal.

[0112] Then, the ultrasonic ranging device can perform correlation calculations based on the fourth signal and the reference signal to generate a correlation output signal. This signal will have a significant peak (i.e., the "main peak") at the position where the "match degree between the fourth signal and the reference signal is the highest". For example, the "main peak time" of the correlation output signal is 0.02 seconds (that is, the moment when the reflected second ultrasonic wave is detected). Based on the ultrasonic round-trip time of 0.02 seconds, the one-way time is 0.01 seconds; given the speed of sound of 340 m / s, the distance between the ultrasonic ranging device and the obstacle can be determined as 340 × 0.01 = 3.4 meters.

[0113] In this possible implementation, the matched component of the echo signal is extracted through correlation operations, which can suppress unmatched interference signals. For example, in high-noise industrial scenarios, correlation operations can filter engine vibration noise and improve the signal-to-noise ratio of the echo signal.

[0114] In this embodiment, the following technical effects are achieved through the coordinated optimization of dynamic amplitude modulation and dynamic gain control:

[0115] 1. Improved anti-interference capability: The gradually changing amplitude envelope of the transmitted signal can reduce the energy of the spectral sidelobes and reduce the risk of resonance with environmental noise (such as engine vibration and ultrasonic signals from other vehicles); through matched filtering and correlation processing, only the echo components that match the amplitude modulation characteristics are retained, suppressing unmatched interference.

[0116] 2. Signal-to-noise ratio and dynamic range optimization: Dynamic amplitude modulation enables the transmitted signal to be transmitted at low amplitude at short distances to avoid receiver saturation, and at high amplitude at long distances to enhance the echo signal strength; dynamic gain control at the receiver compensates for signal attenuation and improves the signal-to-noise ratio of weak echoes at long distances.

[0117] 3. Short-range dead zone elimination: Nonlinear amplitude modulation function (such as low amplitude transmission in the initial stage) makes the short-range echo signal return after the transmission signal ends, avoiding signal superposition problems and effectively shortening the dead zone distance.

[0118] 4. Multi-sensor interference suppression: Through matched filtering technology, only the echo components that match the amplitude modulation characteristics of its own transmitted signal are retained, suppressing interference signals from other vehicles or sensors, and achieving non-interference in the collaborative operation of multiple sensors.

[0119] Figure 5 This is a schematic diagram of the structure of an ultrasonic signal processing circuit provided in an embodiment of this application, as shown below. Figure 5 As shown, the ultrasonic signal processing circuit 500 provided in this embodiment may include a driving circuit 501, a receiving circuit 502, and a processing circuit 503.

[0120] The output terminal of the processing circuit 503 is connected to the driving circuit 501, and the input terminal of the processing circuit 503 is connected to the receiving circuit 502.

[0121] The processing circuit 503 is used to perform amplitude modulation processing on the first signal according to the first amplitude modulation function to obtain the second signal. The first amplitude modulation function is a time-varying function.

[0122] It is also used to adjust the gain of the second signal according to the first gain adjustment function, and transmit the second signal after gain adjustment to the drive circuit 501;

[0123] It is also used to receive the third signal transmitted by the receiving circuit 502, and to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, and to determine the distance information based on the fourth signal;

[0124] The driving circuit 501 is used to receive the second signal sent by the processing circuit 503 and to emit the first ultrasonic wave according to the second signal;

[0125] The receiving circuit 502 is used to determine the third signal from the received second ultrasonic wave and transmit the third signal to the processing circuit 503. The second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave.

[0126] In some embodiments, the first amplitude modulation function is a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

[0127] The first amplitude modulation function and Figure 2 The first amplitude modulation function is the same in the embodiments shown, and will not be described in detail here.

[0128] In some embodiments, the processing circuit 503 can be used to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, wherein the second gain adjustment function is a linear gain adjustment function or a nonlinear gain adjustment function.

[0129] The processing circuit 503 adjusts the gain of the third signal according to the second gain adjustment function to obtain the fourth signal in the same way as described above. Figure 2 The methods in the illustrated embodiments are the same, and will not be described in detail here.

[0130] In some embodiments, the processing circuit 503 is further configured to generate a corresponding reference signal based on the first ultrasonic wave, and determine distance information based on the fourth signal and the reference signal.

[0131] The processing circuit 503 generates a corresponding reference signal based on the first ultrasonic wave, and determines the distance information based on the fourth signal and the reference signal using the same method as described above. Figure 2 The methods in the illustrated embodiments are the same, and will not be described in detail here.

[0132] In some embodiments, the processing circuit 503 is used to perform correlation operations on the fourth signal and the reference signal to generate a correlation output signal; and to determine distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave.

[0133] The processing circuit 503 performs correlation operations on the fourth signal and the reference signal to generate a correlation output signal; and determines the distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave using the same method as described above. Figure 2 The methods in the illustrated embodiments are the same, and will not be described in detail here.

[0134] In some embodiments, the first amplitude modulation function is at least one of a discrete step function, an exponential function, a logarithmic function, and a power function, or the first amplitude modulation function is a combination function including at least two of the exponential function, the logarithmic function, and the power function.

[0135] The ultrasonic signal processing circuit provided in this embodiment can execute the methods implemented in the above method embodiments. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0136] Figure 6 This is a schematic diagram of the structure of an ultrasonic signal processing chip provided in an embodiment of this application. Figure 6 As shown, the ultrasonic signal processing chip 600 may include Figure 5 The ultrasonic signal processing circuit shown can execute the method implemented in the above embodiments. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0137] Figure 7 This is a schematic diagram of an ultrasonic ranging system provided in an embodiment of this application. Figure 7 As shown, the ultrasonic ranging system 700 includes an ultrasonic sensor 701, a processing device 702, and an ultrasonic signal processing chip 703. The ultrasonic sensor 701 can be a transducer, and may include a transmitter and a receiver, or a transceiver. The ultrasonic sensor 701 can be used to transmit and receive ultrasonic waves.

[0138] The ultrasonic chip 703, electrically connected to the ultrasonic sensor 701, may include a driving circuit (containing an amplifier for gaining the transmitted signal) and a receiving circuit (containing an amplifier for gaining the received signal and related modules), and can be used to drive the ultrasonic sensor to transmit a first ultrasonic signal and process the second ultrasonic signal received by the ultrasonic sensor.

[0139] The processing device 702 can be electrically connected to the ultrasonic signal processing chip 703 to receive distance information, and can also receive the relevant output results. The processing device calculates the distance information based on the time of the main peak.

[0140] In this embodiment of the application, the processing device 702 may be a host computer or an electronic control unit (ECU).

[0141] This ultrasonic ranging system can be used to perform the methods implemented in the above method embodiments. Its implementation principle and technical effect are similar, and will not be described in detail here.

[0142] Figure 8 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 8As shown, the electronic device 80 may include a memory 801 and a processor 802. Optionally, the electronic device may also include a transceiver 803, wherein the memory 801 and the processor 802 communicate with each other; for example, the memory 801, the processor 802 and the transceiver 803 may communicate via a communication bus 804, the memory 801 is used to store a computer program, and the processor 802 executes the computer program to implement the method of the above embodiments.

[0143] Optionally, the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps in the method embodiments disclosed in this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0144] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the methods in any of the above method embodiments.

[0145] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the methods in any of the above method embodiments.

[0146] All or part of the steps in the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a readable memory. When the program is executed, it performs the steps of the above method embodiments; and the aforementioned memory (storage medium) includes: read-only memory (ROM), RAM, flash memory, hard disk, solid-state drive, magnetic tape, floppy disk, optical disk, and any combination thereof.

[0147] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processing unit of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processing unit of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0148] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0149] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0150] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

[0151] In this application, the term "comprising" and its variations can refer to non-limiting inclusion; the term "or" and its variations can refer to "and / or". The terms "first", "second", etc., in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. In this application, "multiple" refers to two or more. "And / or" describes 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, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0152] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0153] It should be further noted that although the steps in the flowchart are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0154] It should be understood that the above-described device embodiments are merely illustrative, and the device of this application can also be implemented in other ways. For example, the division of units / modules in the above embodiments is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units, modules, or components may be combined, or integrated into another system, or some features may be ignored or not executed.

[0155] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0156] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0157] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An ultrasonic ranging method, characterized in that, The method includes: The first signal is subjected to amplitude modulation processing according to the first amplitude modulation function to obtain the second signal, wherein the first amplitude modulation function is a time-varying function; The gain of the second signal is adjusted according to the first gain adjustment function, and the first ultrasonic wave is emitted based on the gain-adjusted second signal; The third signal is determined based on the received second ultrasonic wave, where the second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave. The third signal is adjusted according to the second gain adjustment function to obtain the fourth signal; Distance information is determined based on the fourth signal.

2. The method according to claim 1, characterized in that, The first amplitude modulation function is a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

3. The method according to claim 2, characterized in that, The gain adjustment of the third signal to obtain the fourth signal includes: The third signal is adjusted according to the second gain adjustment function to obtain the fourth signal. The second gain adjustment function is a linear amplitude function or a nonlinear amplitude function.

4. The method according to claim 3, characterized in that, The method further includes: A corresponding reference signal is generated based on the first ultrasonic wave; Determining the distance information based on the fourth signal includes: The distance information is determined based on the fourth signal and the reference signal.

5. The method according to claim 4, characterized in that, Determining the distance information based on the fourth signal and the reference signal includes: The fourth signal and the reference signal are correlated to generate a correlation output signal; The distance information is determined based on the peak time of the relevant output signal and the emission time of the first ultrasonic wave.

6. The method according to claim 5, characterized in that, The first amplitude modulation function is at least one of a discrete step function, an exponential function, a logarithmic function, and a power function, or the first amplitude modulation function is a combination function including at least two of the discrete step function, exponential function, logarithmic function, and power function.

7. An ultrasonic signal processing circuit, characterized in that, The ultrasonic signal processing circuit includes a driving circuit, a receiving circuit, and a processing circuit. The output terminal of the processing circuit is connected to the driving circuit, and the input terminal of the processing circuit is connected to the receiving circuit. The processing circuit is used to perform amplitude modulation processing on the first signal according to the first amplitude modulation function to obtain the second signal, wherein the first amplitude modulation function is a time-varying function; It is also used to adjust the gain of the second signal according to the first gain adjustment function, and to transmit the gain-adjusted second signal to the driving circuit; It is also used to receive the third signal transmitted by the receiving circuit, and to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, and to determine the distance information according to the fourth signal; The driving circuit is used to receive the second signal sent by the processing circuit and to emit the first ultrasonic wave according to the second signal; The receiving circuit is used to determine the third signal from the received second ultrasonic wave and transmit the third signal to the processing circuit. The second ultrasonic wave is the ultrasonic wave reflected from the first ultrasonic wave.

8. The circuit according to claim 7, characterized in that, The first amplitude modulation function is a linear amplitude modulation function; or, the first amplitude modulation function is a nonlinear amplitude modulation function.

9. The circuit according to claim 8, characterized in that, The processing circuit is used to adjust the gain of the third signal according to the second gain adjustment function to obtain the fourth signal, wherein the second gain adjustment function is a linear gain adjustment function or a nonlinear gain adjustment function.

10. The circuit according to claim 9, characterized in that, The processing circuit is also used to generate a corresponding reference signal based on the first ultrasonic wave, and to determine the distance information based on the fourth signal and the reference signal.

11. The circuit according to claim 10, characterized in that, The processing circuit is used to perform correlation operations on the fourth signal and the reference signal to generate a correlation output signal; and to determine the distance information based on the peak time of the correlation output signal and the emission time of the first ultrasonic wave.

12. The circuit according to claim 11, characterized in that, The first amplitude modulation function is at least one of a discrete step function, an exponential function, a logarithmic function, and a power function, or the first amplitude modulation function is a combination function including at least two of the discrete step function, exponential function, logarithmic function, and power function.

13. An ultrasonic signal processing chip, characterized in that, The ultrasonic signal processing circuit according to any one of claims 7-12 is used to implement the ultrasonic ranging method according to any one of claims 1-6.

14. An ultrasonic ranging system, characterized in that, It includes an ultrasonic sensor, a processing device, and an ultrasonic signal processing chip, wherein the ultrasonic signal processing chip is used to implement the ultrasonic ranging method according to any one of claims 1-6.

Images