Target detection method, ultrasonic sensor chip and ultrasonic system

Abstract

The embodiment of the invention provides a target detection method, an ultrasonic sensor chip and an ultrasonic system, and the method comprises the steps: carrying out the filtering preprocessing of an obtained echo signal, and obtaining a first signal; for each channel in the at least two channels, determining multiple access amplitude information of the first signal in the channel at a target moment based on the amplitude information of the first signal in the channel and other channels; determining multiple access mapping information of the first signal in the channel based on the amplitude and phase values of the first signal in the other channels; performing fusion processing on the multiple access amplitude information of the first signal in the channel and the multiple access mapping information of the first signal in the channel, and obtaining a fusion threshold value of the effective echo signal of the channel at the target moment; and performing target detection based on the amplitude information of the first signal in the channel and the fusion threshold value. The accuracy of target detection is improved.

Description

[0001] This application claims priority to Chinese patent application No. 202411720413.7, filed with the State Intellectual Property Office on November 27, 2024, with application number 202411720413.7 and application name “Ultrasonic radar detection algorithm, sensor chip and system”; claims priority to Chinese patent application No. 202410382770.0, filed with the State Intellectual Property Office on March 29, 2024, with application number 202410382908.7 and application name “A chirp ultrasonic signal processing method”; claims priority to Chinese patent application No. 202410381905.1, filed with the State Intellectual Property Office on March 29, 2024, with application number 202410381905.1 and application name “An ultrasonic detection system and ultrasonic signal control method”; the entire contents of the above Chinese patents are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of ultrasonic technology, and in particular to a target detection method, an ultrasonic sensor chip, and an ultrasonic system. Background Art

[0003] Ultrasonic radar technology is widely used in fields such as distance measurement, target detection and obstacle avoidance.

[0004] Existing radar target detection methods often rely on complex two-dimensional processing and multi-channel signal analysis. By performing dual processing of radar echo signals based on range and Doppler frequency, they extract target information and achieve target detection. When multiple targets are present, these methods can interfere with each other's signals, leading to high false alarm and missed detection rates and reduced target detection accuracy. Summary of the Invention

[0005] In view of this, the present application provides a target detection method, an ultrasonic sensor chip and an ultrasonic system to solve the problem of low target detection accuracy in the prior art.

[0006] In a first aspect, an embodiment of the present application provides a target detection method, comprising:

[0007] Performing filtering preprocessing on the acquired echo signal to obtain a first signal;

[0008] For each of the at least two channels, determining, at a target time, multi-access amplitude information of the first signal in the channel based on amplitude information of the first signal in the channel and other channels; the multi-access amplitude information is used to describe the validity of the first signal in the channel;

[0009] Determining, based on the amplitude and phase values of the first signal in the other channels, multiple access mapping information of the first signal in the channel; the multiple access mapping information is used to describe amplitude and phase mapping information of the first signal between the channel and the other channels;

[0010] performing fusion processing on the multi-access amplitude information of the first signal on the channel and the multi-access mapping information of the first signal on the channel to obtain a fusion threshold value of a valid echo signal of the channel at the target time;

[0011] Target detection is performed based on the amplitude information of the first signal in the channel and the fusion threshold value.

[0012] In a possible implementation of the first aspect, determining, at the target time, the multi-access amplitude information of the first signal in the channel based on the amplitude information of the first signal in the channel and the other channels includes:

[0013] Based on the target time, determining amplitude information of the first signal in the channel and upper boundary amplitude information in other channels;

[0014] Determining first amplitude threshold information based on upper boundary amplitude information of the first signal in other channels and preset echo signal ratio information between the channel and other channels;

[0015] If the amplitude information of the first signal in the channel is not less than the first amplitude threshold information, the first signal is determined to be a valid echo signal, and the amplitude information of the first signal in the channel is used as the multi-access amplitude information of the first signal in the channel; or

[0016] If the amplitude information of the first signal in the channel is less than the first amplitude threshold information, the first signal is determined to be an invalid echo signal, and the first preset value is used as the multi-access amplitude information of the first signal in the channel.

[0017] In a possible implementation manner of the first aspect, determining the multiple access mapping information of the first signal on the channel based on the amplitude and phase values of the first signal on the other channels includes:

[0018] Determining a first time based on the target time and a preset window length;

[0019] determining the amplitude and phase values of the first signal in the other channels within a first time;

[0020] The multiple access mapping information of the first signal in the channel is calculated according to the amplitude and phase values of the first signal in the other channels and a preset mapping relationship.

[0021] In a possible implementation of the first aspect, the method further includes:

[0022] Obtain threshold reference information;

[0023] The fusing the multi-access amplitude information of the first signal in the channel and the multi-access mapping information of the first signal in the channel to obtain a fusion threshold value of a valid echo signal of the channel at the target time includes:

[0024] The multi-access amplitude information of the first signal in the channel, the multi-access mapping information of the first signal in the channel, and the threshold reference information are fused to obtain a fusion threshold value of a valid echo signal of the channel at the target time.

[0025] In a possible implementation of the first aspect, obtaining threshold reference information includes:

[0026] When the first signal is an invalid echo signal, the amplitude value information of the first signal is determined as the threshold reference information.

[0027] In a possible implementation of the first aspect, performing filtering preprocessing on the acquired echo signal to obtain the first signal includes:

[0028] The acquired echo signal is filtered and preprocessed using a preset matched filter to obtain a first signal; wherein the impulse response signal of the matched filter is a time-reversed signal of the transmitted signal corresponding to the echo signal.

[0029] In a possible implementation of the first aspect, performing filtering preprocessing on the acquired echo signal to obtain the first signal includes:

[0030] converting the echo signal into a digital echo signal;

[0031] Converting the digital echo signal into a frequency domain signal;

[0032] performing enhancement processing on a first sub-frequency domain signal in the frequency domain signal and suppressing processing on a second sub-frequency domain signal in the frequency domain signal to obtain a second signal; wherein the first sub-frequency domain signal is a signal in the frequency domain signal whose frequency change pattern is a target change pattern, and the second sub-frequency domain signal is a signal in the frequency domain signal whose frequency change pattern is a non-target change pattern;

[0033] Adjusting the phase of a signal in a target frequency band in the second signal to obtain a third signal;

[0034] The third signal is converted into a time domain signal to obtain the first signal.

[0035] In a possible implementation of the first aspect, performing filtering preprocessing on the acquired echo signal to obtain the first signal includes:

[0036] The acquired echo signal is filtered and preprocessed using a preset adaptive filtering method to obtain a first signal.

[0037] In a possible implementation of the first aspect, the method further includes:

[0038] A historical echo signal is acquired, and the fusion threshold is adjusted based on amplitude value information of the historical echo signal.

[0039] In a possible implementation of the first aspect, the echo signal is acquired using a single snapshot.

[0040] In a possible implementation of the first aspect, the method further includes:

[0041] Sends a driving signal to the ultrasonic sensor.

[0042] In a second aspect, an embodiment of the present application provides an ultrasonic sensor chip, wherein the ultrasonic sensor chip adopts a MIMO radar structure and is used for:

[0043] electrically connected to the ultrasonic sensor, and sending a driving signal to the ultrasonic sensor to drive the ultrasonic sensor to emit an ultrasonic signal;

[0044] Receive an echo signal formed by an ultrasonic signal, and perform target detection based on the received echo signal within a signal cycle; wherein the ultrasonic sensor chip performs target detection by executing the target detection method according to any one of the first aspects.

[0045] In a possible implementation manner of the second aspect, the driving signal includes a chirp signal.

[0046] In a possible implementation manner of the second aspect, sending a driving signal to the ultrasonic sensor includes:

[0047] When sending a driving signal to the ultrasonic sensor, increasing the duration of continuous transmission of the chirp signal based on a preset duration;

[0048] and / or, adjusting the frequency range of the chirp signal based on the operating frequency range of the ultrasonic sensor, so that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor;

[0049] And / or, based on a preset power adjustment value, adjusting the transmission power of the chirp signal.

[0050] In a possible implementation of the second aspect, a degree of overlap between a frequency range of the chirp signal and a frequency range of a first chirp signal is less than a preset threshold; wherein the first chirp signal is a chirp signal emitted by an ultrasonic sensor chip other than the ultrasonic sensor chip.

[0051] In a possible implementation of the second aspect, the device is further configured to:

[0052] Based on the frequency range of the chirp signal, the operating frequency range of the ultrasonic sensor is adjusted so that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor.

[0053] In a possible implementation of the second aspect, the driving signal further includes a driving signal with a fixed frequency;

[0054] The sending of a driving signal to the ultrasonic sensor comprises:

[0055] Sending a chirp signal to the ultrasonic sensor, and when no target is detected within a first preset distance threshold, sending the fixed frequency driving signal to the ultrasonic sensor; or,

[0056] The fixed-frequency driving signal is sent to the ultrasonic sensor, and when no target is detected within a second preset distance threshold, a chirp signal is sent to the ultrasonic sensor, and when no target is detected within a third preset distance threshold, the fixed-frequency driving signal is sent to the ultrasonic sensor; the second preset distance threshold is less than the third preset distance threshold.

[0057] In a possible implementation manner of the second aspect, the chirp signal carries coding information.

[0058] In a third aspect, an embodiment of the present application provides an ultrasonic sensor system, comprising: an ultrasonic sensor and an ultrasonic sensor chip; the ultrasonic sensor chip is configured to execute the target detection method described in any one of the first aspects above;

[0059] Alternatively, the ultrasonic sensor chip includes the ultrasonic sensor chip described in any one of the second aspects above.

[0060] In a possible implementation of the third aspect, the ultrasonic sensor includes a first ultrasonic sensor and a second ultrasonic sensor, and the first ultrasonic sensor is disposed adjacent to the second ultrasonic sensor;

[0061] The time interval between the time when the first ultrasonic sensor transmits the ultrasonic signal and the time when the second ultrasonic sensor transmits the ultrasonic signal is a first time length.

[0062] In a possible implementation of the third aspect, the ultrasonic sensors include a plurality of ultrasonic sensors, wherein signal emission angles of two adjacent ultrasonic sensors are different;

[0063] And / or, the multiple ultrasonic sensors include a first group of ultrasonic sensors and a second group of ultrasonic sensors; wherein, the first group of ultrasonic sensors includes at least two third ultrasonic sensors arranged along the first direction; the second group of ultrasonic sensors includes at least two fourth ultrasonic sensors arranged along the first direction; the first group of ultrasonic sensors and the second group of ultrasonic sensors are arranged along the second direction, and in the second direction, the third ultrasonic sensor in the first group of ultrasonic sensors and the fourth ultrasonic sensor in the second group of ultrasonic sensors do not overlap, and the first direction intersects the second direction.

[0064] Using the solution provided in an embodiment of the present application, the acquired echo signal is filtered and preprocessed to obtain a first signal. For each of at least two channels, at a target time, based on the amplitude information of the first signal in the channel and other channels, the multi-address amplitude information of the first signal in the channel is determined. Based on the amplitude and phase values of the first signal in the channel and other channels, the multi-address mapping information of the first signal in the channel is determined. The multi-address amplitude information of the first signal in the channel and the multi-address mapping information of the first signal in the channel are fused to obtain a fusion threshold value for a valid echo signal in the channel at the target time. Target detection is performed based on the amplitude information of the first signal in the channel and the fusion threshold value. Thus, in an embodiment of the present application, for each of the at least two channels, the multi-address amplitude information and the multi-address mapping information of the first signal in the channel can be obtained at the target time. By fusing the multi-address amplitude information and the multi-address mapping information, a fusion threshold value for a valid echo signal in the channel at the target time is obtained. In this way, by integrating signal data from different related channels, the multi-access amplitude information and multi-access mapping information are fused to obtain a fusion threshold value. The fusion threshold value can more comprehensively reflect the signal environment of the above channels at the target moment, reduce multi-access interference, and improve the accuracy of target detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0066] Figure 1 A flowchart of a target detection method provided in an embodiment of the present application;

[0067] Figure 2 A flowchart of another target detection method provided in an embodiment of the present application;

[0068] Figure 3 A schematic diagram of a target detection scenario provided in an embodiment of the present application;

[0069] Figure 4 A schematic diagram of another target detection scenario provided in an embodiment of the present application;

[0070] Figure 5 A schematic diagram of another target detection scenario provided in an embodiment of the present application;

[0071] Figure 6 A schematic diagram of another target detection scenario provided in an embodiment of the present application;

[0072] Figure 7 A flowchart of another target detection method provided in an embodiment of the present application;

[0073] Figure 8 A flowchart of another target detection method provided in an embodiment of the present application;

[0074] Figure 9 A schematic structural diagram of an ultrasonic sensor system provided in an embodiment of the present application;

[0075] Figure 10 A schematic structural diagram of another ultrasonic sensor system provided in an embodiment of the present application;

[0076] Figure 11 A schematic diagram of the arrangement of ultrasonic sensors provided in an embodiment of the present application. DETAILED DESCRIPTION

[0077] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0078] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0079] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0080] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0081] Before providing a detailed introduction to the embodiments of the present application, the terms that are applied or may be applied to the embodiments of the present application are first explained.

[0082] The correlation module uses the local correlation coefficient to perform multiplication and accumulation operations on the target's reflected echo data. As the core computational module for radar signal processing, it generates correlation peaks at the signal arrival time. Furthermore, the correlation module can process both baseband signals with a zero center frequency and intermediate frequency or radio frequency signals with non-zero center frequencies. It can process both the I / Q signals corresponding to a given receiving unit or just one of the signals (I or Q).

[0083] Beam refers to the area or direction covered by the radar when transmitting and receiving signals. Multi-channel can be multiple related channels of the same beam channel or different related channels of different beams.

[0084] MIMO radars may use different waveforms or coding techniques to distinguish signals from different targets. When the receiver processes multiple waveforms using different correlation coefficients, if there is a high correlation between the waveforms and the correlation coefficient, the channel is called a correlated channel. If there is a low correlation between the waveforms and the correlation coefficient, the channel is called a orthogonal channel.

[0085] MIMO (Multiple Input Multiple Output) radar technology utilizes multiple antennas at both the transmitting and receiving ends, enabling simultaneous transmission and reception of multiple ultrasonic signals, significantly improving the radar system's detection capabilities. Existing radar target detection methods often employ complex two-dimensional processing and multi-channel signal analysis, extracting target information by performing dual processing of radar echo signals based on range and Doppler frequency. However, these methods, when multiple targets are present, can interfere with each other's signals, leading to high false alarm and missed detection rates and reduced target detection accuracy.

[0086] In some technologies, the conventional driving signal for ultrasonic sensors is a fixed-frequency signal. Fixed-frequency driving signals offer concentrated energy, long detection range, and simple driving methods. However, they have weak anti-interference capabilities, making it difficult to accurately identify targets and resulting in measurement errors. Chirp signals are frequency-modulated signals whose frequency varies with time. They possess broadband characteristics, excellent time-frequency characteristics, and high resolution. In recent years, chirp signals have become increasingly popular in ultrasonic radar systems due to their advantages, such as high temporal resolution and high signal-to-noise ratio.

[0087] However, because chirp signals are frequency-modulated signals whose frequency varies over time, their performance gradually weakens as the transmission distance increases. This results in significant limitations in the performance of chirp signals in long-distance target detection, and the detection distance is smaller than that of traditional fixed-frequency ultrasonic signals. Furthermore, chirp signals are divided into chirp-up signals and chirp-down signals. During target detection, chirp-up signals and chirp-down signals may coexist, causing mutual interference or crosstalk between the chirp-up signals and the chirp-down signals, leading to misjudgment during target detection and reducing the accuracy of target detection. Furthermore, there may be frequency overlap between the chirp-up signals and the chirp-down signals, which can cause the echo signals of the chirp-up signals and the chirp-down signals to cancel each other out, reducing the accuracy of the echo signals and further reducing the accuracy of target detection.

[0088] To address the above issues, embodiments of the present application provide a target detection method, an ultrasonic sensor chip, and an ultrasonic system. Specifically, the method comprises: performing filtering preprocessing on an acquired echo signal to obtain a first signal; determining, for each of at least two channels, multi-address amplitude information of the first signal in that channel at a target time based on the amplitude information of the first signal in that channel and other channels; determining multi-address mapping information of the first signal in that channel based on the amplitude and phase values of the first signal in that channel and other channels; fusing the multi-address amplitude information of the first signal in that channel and the multi-address mapping information of the first signal in that channel to obtain a fusion threshold value for a valid echo signal in that channel at the target time; and performing target detection based on the amplitude information of the first signal in that channel and the fusion threshold value. Thus, in embodiments of the present application, for each of the at least two channels, multi-address amplitude information and multi-address mapping information of the first signal in that channel can be obtained at the target time. By fusing the multi-address amplitude information and multi-address mapping information, a fusion threshold value for a valid echo signal in that channel at the target time is obtained. In this way, by integrating signal data from different related channels and fusing multi-access amplitude information and multi-access mapping information to obtain a fusion threshold, the fusion threshold can more comprehensively reflect the signal environment of the aforementioned channels at the target time, thereby reducing multi-access interference and improving target detection accuracy. This is explained in detail below.

[0089] See also Figure 1 , is a flow chart of a target detection method provided in an embodiment of the present application. Figure 1 As shown, the method includes:

[0090] Step S101: Perform filtering preprocessing on the acquired echo signal to obtain a first signal.

[0091] In order to better measure the distance, an ultrasonic system can be installed in vehicles and other equipment, and the distance between the vehicle and the obstacle can be measured through the ultrasonic system. The ultrasonic system includes an ultrasonic sensor chip and an ultrasonic sensor. The ultrasonic sensor chip can send a driving signal to the ultrasonic sensor. After receiving the driving signal, the ultrasonic sensor can emit an ultrasonic signal based on the driving signal. After the ultrasonic signal is reflected by the object, it is received by the ultrasonic sensor. The reflected signal received by the ultrasonic sensor is the echo signal. The ultrasonic sensor transmits the received echo signal to the ultrasonic sensor chip. The ultrasonic sensor chip performs target detection based on the echo signal. In an embodiment of the present application, in order to improve the accuracy of target detection by the ultrasonic sensor chip. After obtaining the echo signal, the echo signal can be filtered and pre-processed to preliminarily filter out the noise signal in the echo signal to obtain a first signal.

[0092] Step S102: For each of the at least two channels, determine the multi-access amplitude information of the first signal in the channel based on the amplitude information of the first signal in the channel and other channels at the target time.

[0093] The multiple access amplitude information is used to describe the effectiveness of the first signal in the channel.

[0094] In the embodiments of the present application, since MIMO radar is a multi-input, multi-output radar system, when a MIMO radar system is used in an ultrasonic system, ultrasonic signals are transmitted through different channels, and echo signals are received by different channels, thereby enabling target detection based on the echo signals. When multiple targets are present simultaneously, the echo signal within a channel includes not only the signal reflected from the ultrasonic signal transmitted within that channel, but also signals emitted by ultrasonic signals transmitted in other channels. These signals emitted by ultrasonic signals transmitted in other channels can be considered noise signals, reducing the accuracy of target detection. Therefore, for each of the at least two channels, it is necessary to determine whether the echo signal received by that channel is valid, that is, to determine whether the echo signal received by that channel is a signal reflected from the ultrasonic signal transmitted within that channel, in order to reduce interference between signals. Furthermore, since the amplitude value information of the echo signals varies at different times, the multi-address amplitude information of the first signal in that channel can be determined at the time when determining whether the echo signal is a valid echo signal. Based on this, the amplitude information of the first signal in that channel and other channels at the target time, such as the amplitude ratio information, can be analyzed to determine whether the first signal is valid within that channel, that is, to determine the multi-address amplitude information of the first signal in that channel. The target time is the time at which it is necessary to determine whether the echo signal is a valid echo signal. For the convenience of description, the current channel may be represented by the target channel.

[0095] As a possible implementation manner, determining the multi-access amplitude information of the first signal in the channel based on the amplitude information of the first signal in the channel and other channels at the target time includes:

[0096] Based on the target time, the amplitude information of the first signal in the channel and the upper boundary amplitude information in other channels are determined.

[0097] The first amplitude threshold information is determined based on the upper boundary amplitude information of the first signal in other channels and the echo signal ratio information between the preset channel and other channels.

[0098] If the amplitude information of the first signal in the channel is not less than the first amplitude threshold information, the first signal is determined to be a valid echo signal, and the amplitude information of the first signal in the channel is used as the multi-access amplitude information of the first signal in the channel. Or,

[0099] If the amplitude information of the first signal in the channel is less than the first amplitude threshold information, the first signal is determined to be an invalid echo signal, and the first preset value is used as the multiple access amplitude information of the first signal in the channel.

[0100] That is, after obtaining the first signal, the amplitude information of the first signal in the target channel at the target moment can be determined based on the intensity information of the first signal in the target channel at the target moment. In order to improve the accuracy of judging the effectiveness of the first signal in the target channel at the target moment, a time window length can be preset. According to the target moment and the preset time window length, the amplitude upper boundary extraction time period is determined. Among them, the preset time window length can characterize the lower boundary time and upper boundary time of the amplitude upper boundary extraction time period based on the target moment. For example, the preset time window length records that the lower boundary time of the amplitude upper boundary extraction time period based on the target moment is t before the target moment. Ln Seconds, the upper boundary time of the amplitude upper boundary extraction time period is t after the target time Rn Seconds. Among them, t Ln and t Rn is a number greater than 0, t Ln With t Rn The values of can be the same or different. In this way, the amplitude upper boundary extraction time period can be determined based on the target time and the preset time window length. Alternatively, the preset time window length records the length of the amplitude upper boundary extraction time period based on the target time. In this case, the target time can be used as the middle moment of the amplitude upper boundary extraction time period to determine the upper boundary time and the lower boundary time of the amplitude upper boundary extraction time period. Assume that t Ln and t Rn If both are 10 seconds, the upper amplitude boundary extraction time period can be set to [t0-10, t0+10], where t0 represents the target time. After determining the upper amplitude boundary extraction time period, the upper amplitude boundary information of the first signal in other channels can be determined within the upper amplitude boundary extraction time period. The upper amplitude boundary information is the maximum amplitude value of the first signal in other channels within the upper amplitude boundary extraction time period.

[0101] For example, assuming that t0 represents the target time, chl0 represents the target channel, and chl1 to chlN represent the other channels in at least two channels except the target channel. For chl1 to chlN, the amplitude upper boundary extraction time period is determined to be [t0-t Ln ,t0+t Rn For each of the other channels in chl1 to chlN, extract the time period [t0-t Ln ,t0+t Rn], the maximum amplitude value of the first signal in the other channel is determined as the upper boundary amplitude information of the first signal in the other channel. For example, for chl1, the time period [t0-t Ln ,t0+t Rn ], the maximum amplitude value of the first signal in chl1 is determined as the upper boundary amplitude information of the first signal in chl1. In this way, the upper boundary amplitude information of each other conductive state can be determined as Max chl1 (t0), ..., Max chln (t0). Where,

[0102] In an embodiment of the present application, a theoretical proportional relationship between the echo signal in the target channel and other channels can be pre-set. That is, the echo signal ratio information between the target channel and other channels is pre-set. Typically, the intensity of the corresponding echo signal in the target channel should be greater than the intensity of the signal in other channels. Furthermore, to account for the influence of non-ideal factors such as noise, the upper boundary value of the echo ratio between the target channel and each other channel can be determined from the preset echo signal ratio information between the target channel and other channels. For example, for the chl1 channel among other channels, the maximum value of the echo signal ratio value in the preset echo signal ratio information between the target channel and the chl1 channel can be used as the upper boundary value of the echo ratio between the target channel and the chl1 channel. In this way, the first amplitude threshold information can be calculated based on the upper boundary amplitude information of the first signal in other channels and the upper boundary value of the echo ratio between the target channel and other channels.

[0103] In some embodiments, function information for calculating the first amplitude threshold information based on the upper boundary amplitude information of the first signal in other channels and the echo signal ratio information between the preset channel and other channels can be pre-set according to actual needs, so as to calculate the first amplitude threshold information based on the function information.

[0104] As in the above example, suppose N 01 ~N 0N It is the theoretical proportional relationship between the echo signals of the same target in different channels.

[0105] Where n = 1, 2, ..., N. Taking into account the influence of non-ideal factors such as noise, the upper boundary value of the echo ratio between the target channel and each other channel can be determined, that is, N on The upper boundary value N on，HFunctions f1 and f2 can be pre-set to calculate the first amplitude threshold information based on the upper boundary amplitude information of the first signal in other channels and the upper boundary value of the echo ratio between the target channel and other channels. That is, the first amplitude threshold information can be calculated using the following formula.

[0106] S 门限1 =f2(w1f1(N 01,H Max chl1 (t0)),…,w N f N (N 0N,H Max chlN (t0))). Where S 门限1 represents the first amplitude threshold information, f1(·), f2(·) represent arbitrary functions, w N represents the weighted value corresponding to f1(·), which can be preset. The above f1(·), f2(·) functions can be replaced by any other expressions as long as the expressions used include the description relationship of the multiple access amplitude signals between different channels.

[0107] If the amplitude information of the first signal in the target channel is not less than the first amplitude threshold information, it is determined that the intensity of the first signal is large, and the echo signal in the target channel with an amplitude not less than the first amplitude threshold information can be determined as a valid echo signal, which can be used to detect the target.

[0108] Alternatively, if the amplitude information of the first signal in the target channel is less than the first amplitude threshold information, it is determined that the strength of the first signal is weak, and the echo signal in the target channel with an amplitude less than the first amplitude threshold information can be determined as an invalid echo signal, and the first signal is determined as a noise signal.

[0109] As shown in the above example, when chl0 represents the target channel, the amplitude information of the first signal in the target channel can be expressed as P chl0 (t0), at this time, whether the first signal is a valid echo signal can be indicated by the following information function.

[0110]

[0111] Similarly, the same calculation is performed for other channels. chl1 (t),a chl2 (t),…,a chlN (t).

[0112] In this way, the information function can be used to determine the relationship between the first signal's amplitude and the first amplitude threshold information, thereby determining whether the first signal at the target time is a valid echo signal. In other words, the information function can be used to distinguish between a valid echo signal and a noise signal, improving target detection accuracy. The first amplitude threshold information provides a reference for determining signal strength, ensuring that the first signal is only determined to be a valid echo signal when the signal strength is significantly higher than the first amplitude threshold information.

[0113] In some embodiments, after acquiring the first signal, correlation operation and / or beam operation can be performed on the first signal to further eliminate the noise signal in the first signal, and the first signal after the correlation operation and / or beam operation can be used to obtain multiple access amplitude information.

[0114] It should be understood that after acquiring the first signal, other operations may be performed on the first signal to further suppress the noise signal in the first signal, and multiple access amplitude information may be acquired on the first signal after the other operations.

[0115] Step S103: Determine the multiple access mapping information of the first signal in the channel based on the amplitude and phase values of the first signal in other channels.

[0116] The multiple access mapping information is used to describe the amplitude and phase mapping information of the first signal between the channel and other channels.

[0117] In an embodiment of the present application, in order to improve the accuracy of target detection, when performing target detection, it is necessary to consider not only the multi-access amplitude information of the signal but also the characteristics of the signal in different channels. Therefore, it is necessary to obtain the multi-access mapping information of the signal. The multi-access mapping information can describe the amplitude and phase mapping information of the first signal between the target channel and other channels. Based on this, after obtaining the first signal, the amplitude and phase values of the first signal in other channels at the target moment can be obtained based on the intensity information and phase information of the first signal. In some embodiments, the amplitude and phase values of the first signal in other channels can be directly obtained through filtering.

[0118] After the amplitude and phase values of the first signal in other channels are acquired, the multiple access mapping information of the first signal in the channels may be obtained based on a preset mapping relationship.

[0119] It should be noted that the preset mapping relationship can be a mapping relationship pre-set according to actual needs. The mapping relationship can be a mapping function relationship or other forms of mapping relationships. The embodiments of the present application do not limit this.

[0120] In some embodiments, determining the multiple access mapping information of the first signal in the channel based on the amplitude and phase values of the first signal in other channels includes:

[0121] The first time is determined based on the target time and the preset window length.

[0122] The amplitude and phase values of the first signal in other channels are determined within a first time.

[0123] The multiple access mapping information of the first signal in the channel is calculated according to the amplitude and phase values of the first signal in other channels and the preset mapping relationship.

[0124] That is, in order to improve the accuracy of determining the multi-address mapping information of the first signal in the target channel at the target time, after determining the target time, the first time can be determined according to the preset window length. The preset window length can represent the lower boundary time and upper boundary time of the first time based on the target time. For example, the preset window length records the lower boundary time of the first time based on the target time as t′ before the target time. Ln seconds, the upper boundary time of the first time is t′ after the target time Rn Seconds. Among them, t′ Ln and t′ Rn is a number greater than 0, t′ Ln and t′ Rn The values of can be the same or different. In some embodiments, t' Ln With t Ln Equal, t′ Rn With t Rn are equal. In this way, the first time can be determined based on the target moment and the preset window length. Alternatively, the length of the first time based on the target moment is recorded in the preset window length. At this time, the target moment can be used as the middle moment of the first time to determine the upper boundary time and the lower boundary time of the first time. After determining the first time, the amplitude and phase values of the first signal in other channels within the first time can be obtained. In some embodiments, when the first signal is filtered, the amplitude and phase values of the first signal at each time in other channels can be obtained, thereby obtaining the amplitude and phase values of the first signal in other channels within the first time. Of course, other methods can also be used to obtain the amplitude and phase values of the first signal at each time in other channels, for example, based on the amplitude and phase information of the first signal in other channels, and the embodiments of the present application are not limited to this.

[0125] For example, assuming that t0 represents the target time, chl0 represents the target channel, and chl1 to chlN represent the other channels in at least two channels except the target channel. For chl1 to chlN, the first time is determined according to the target time t0 and the preset window length. Assume that the first time is [t0-t′ Ln ,t0+t′ Rn ]; For chl1~chlN, the amplitude and phase values of the first signal in the first time of chl1~chlN can be obtained. That is, obtain tm ∈[t0-t′ Ln ,t0+t′ Rn ],n=1,…,N; where, Indicates the amplitude and phase values of the first signal at time tm in other channels chln. In this way, the first time [t0-t′] of the first signal in each other channel can be obtained. Ln ,t0+t′ Rn ] within the amplitude and phase values.

[0126] Based on the amplitude and phase values of the first signal relative to other signals, a preset mapping relationship can be used to calculate the multi-address mapping information of the first signal in the target channel. In some embodiments, the preset mapping relationship can be a mutual ambiguity function. Of course, the preset mapping relationship can also be other mapping relationships, and this embodiment of the application is not limited to this.

[0127] As shown in the above example, assuming that the preset mapping relationship is a mutual ambiguity function, the mutual ambiguity function of the other channel chln and the target channel chl0 is xcorr n0 (t). Wherein, chln represents the nth other channel, n = 1, ..., N. For the convenience of description, the following takes the other channel chln as the first other channel chl1 as an example. In this case, the mutual ambiguity function of chl0 and chl1 is xcorr 10 (t). Specifically, if the peak value of any signal echo in chl1 is at t m Time (expressed as x(t)*δ(tt m )), then its correlation output on chl0 (i.e., the multiple access interference caused by x(t) on chl0) can be expressed as xcorr 10 (t)*δ(tt m ), where * represents the convolution symbol, so the multiple access mapping information can be expressed as: b n0 (t m →t0)=xcorr 10 (t)* t=t0. Where, b n0 (t m →t0) The amplitude and phase values of the first signal at time t0 of chl0.

[0128] For the convenience of description, the above expression can be simplified. For example, b n0 (t m →t0) is simplified to b n0 (t m0 ). M(n) represents the amplitude and phase point used in chln The number is mapped to the amplitude-phase function b in chl0 chl0 (t0) can be expressed as: chl0(t0)=f3(w n ' m b n0 (t m0 )),n=1,…,N,m=1,…,M. Where f3(·) represents an arbitrary function, and b n0 (t m0 ) can be 0, w n ' m The corresponding weighted value can be preset. In this way, the multi-access mapping information of the first signal in the target channel can be obtained. The characteristics of the first signal in different channels can be obtained by analyzing the multi-access mapping information, which is helpful for subsequent target detection.

[0129] Step S104: performing fusion processing on the multi-address amplitude information of the first signal in the channel and the multi-address mapping information of the first signal in the channel to obtain a fusion threshold value of a valid echo signal of the channel at a target time.

[0130] In an embodiment of the present application, to improve target detection accuracy and reduce multi-access interference, after obtaining the multi-access amplitude information of the first signal in the target channel and the multi-access mapping information of the first signal in the target channel, the multi-access amplitude information of the first signal in the channel and the multi-access mapping information of the first signal in the channel can be fused to obtain a fusion threshold value for the effective echo signal of the target channel at the target time. In some embodiments, a fusion function can be pre-set, so that the multi-access amplitude information of the first signal in the channel and the multi-access mapping information of the first signal in the channel can be fused using the preset fusion function.

[0131] As shown in the above example, the multi-address amplitude information of the first signal in the channel and the multi-address mapping information of the first signal in the channel can be fused using a preset fusion function to obtain a fusion threshold value. That is, th chl0 (t0) = g(a chl0 (t),b chl0 (t)). Among them, th chl0 (t0) represents the fusion threshold value of the effective echo signal of the target channel chl0 at the target time t0. L ,t0+t R ]. Among them, t L Not less than t Ln and t′ Ln , t R No more than t Rn and t′ Rn In some embodiments, t L , t Ln and t′ Ln All three are equal, t R , t Rn and t′Rn The three are equal. g(·) is any function and can be set to t=t0.

[0132] Step S105: Target detection is performed based on the amplitude information of the first signal in the channel and the fusion threshold value.

[0133] That is, after obtaining the amplitude value information and fusion threshold value of the first signal in the target channel, if the amplitude value information of the first signal in the target channel is not less than the fusion threshold value, it can be determined that there is target information in the first signal. At this time, the target can be detected based on the first signal.

[0134] In other embodiments, to improve the accuracy of target detection, performing target detection based on the amplitude information of the first signal in the channel and the fusion threshold value includes:

[0135] Based on the amplitude information of the first signal in the channel and the fusion threshold value, if the amplitude information of the first signal in the channel is not less than the fusion threshold value, and at the target time, the amplitude value of the first signal is the peak value, that is, P chl0 If (t0) is a maximum value, it can be determined that there is target information; otherwise, it can be determined that there is no target information in the first signal.

[0136] In this way, in the embodiment of the present application, by integrating signal data from different related channels, the multi-access amplitude information and the multi-access mapping information are fused to obtain a fusion threshold value. The fusion threshold value can more comprehensively reflect the signal environment of the above-mentioned channel at the target moment, reduce multi-access interference, and improve the accuracy of target detection.

[0137] In some embodiments, reference Figure 2 As shown, the above method also includes:

[0138] Step S106: Acquire threshold reference information.

[0139] In the embodiment of the present application, in order to improve the accuracy of target detection, other reference information may be fused when generating the fusion threshold value, that is, threshold reference information may also be fused. Therefore, threshold reference information may be obtained.

[0140] In some embodiments, the threshold reference information can be determined by the user according to actual needs. For example, it can be target auxiliary information, target prior information and target detection history information based on non-ultrasonic detection means such as images, or information such as the processing output of any digital information such as sensor data, communication data and system control data. In this way, the threshold reference information can be obtained by reading sensor data, etc.

[0141] In other embodiments, to more effectively identify and filter interference signals, improve target signal detection capabilities, enhance anti-interference capabilities in complex environments, and ensure good target detection performance even in high-noise environments, noise amplitude information can be used as threshold reference information. In this case, obtaining the threshold reference information includes determining the amplitude value information of the first signal as the threshold reference information when the first signal is an invalid echo signal. That is, when the first signal is an invalid echo signal, the amplitude value information of the first signal can be used as the threshold reference information to generate a more accurate fusion threshold value.

[0142] At this time, in the above step S104, the multi-access amplitude information of the first signal in the channel and the multi-access mapping information of the first signal in the channel are fused to obtain the fusion threshold value of the effective echo signal of the channel at the target time, which includes:

[0143] The multi-access amplitude information of the first signal in the channel, the multi-access mapping information of the first signal in the channel and the threshold reference information are fused to obtain a fusion threshold value of a valid echo signal of the channel at a target time.

[0144] That is, after obtaining the threshold reference information, the multi-address amplitude information of the first signal in the channel, the multi-address mapping information of the first signal in the channel and the threshold reference information can be fused to obtain the fusion threshold value of the effective echo signal of the channel at the target time. chl0 (t0) = g(a chl0 (t),b chl0 (t),c chl0 (t)). Where c chl0 (t) represents the threshold reference information of the target channel at time t.

[0145] For example, the ultrasonic radar in bistatic working mode is used as an example. In this case, there are only two channels, chl0 and chl1. Figure 3 As shown in the figure, chl0 is the correlation channel of the t1 transmission signal, and chl1 is the orthogonal channel of the t1 transmission signal. The correct fusion threshold should generate a threshold value corresponding to a lower peak value in chl0 and a threshold value corresponding to a higher peak value in chl1. The first signal received in chl0 is referenced Figure 4 As shown. The curve corresponding to the first signal is represented by dat. The first signal reference received in chl1 Figure 5 Assume that the theoretical ratio of the target echo signal in the chl0 channel and the chl1 channel is N 01 = 3. The theoretical ratio of the target echo signal in the chl1 channel and the chl0 channel is N 10 =3. Let N 01,H =N 01 ,N10,H =N 10 , assuming the preset window length is 64 data points, that is, 32 data points are taken before the target time t0, and 32 data points are taken after the target time t0. Based on the input data, assuming f1(x) = x, f2(x) = x and w1 = 1, w2 = 1, the information function a of the chl0 channel can be obtained chl0 (t), information function a of chl1 channel chl1 (t), reference Figure 4 and Figure 5 As shown. Among them, Figure 4 and Figure 5 a(t) is used to represent a chl0 (t) and a chl1 (t) curve. Figure 4 and Figure 5 It can be seen that chl1 is a positive channel, and its signal amplitude is relatively small compared to the related channel chl0. chl1 (t)=0.

[0146] Figure 6 Schematic diagram of multiple access mapping information between two channels chl0 and chl1 provided in the embodiment of the present application. Assume that the modulus of the mutual ambiguity function in chl0 and chl1 is as follows: Figure 6 To simplify the processing, the mutual fuzzy function can be expressed using its modulus value. f3 is the maximum value operation, and b 10 (t m0 ) has a weight of 2, b 01 (t m0 ) has a weight of 2. This allows us to calculate the b in chl0 chl0 (t), b in chl1 chl1 (t), such as Figure 4 and Figure 5 As shown in b(t).

[0147] Assumption c chl0 (t) and c chl1 (t) is the amplitude information and mean square error information of the noise signal. chl0 (t), b chl0 (t) and c chl0 (t) is fused to obtain the fusion threshold corresponding to chl0, refer to Figure 4 In this way, we can use a chl1 (t), b chl1 (t) and c chl1 (t) is fused to obtain the fusion threshold corresponding to chl1, refer to Figure 5 As shown in th(t).

[0148] Compare the first signal in chl0 and chl1 with the fusion threshold. If the amplitude of the first signal is higher than the fusion threshold and the point is a peak, it can be determined that the point is the target. Figure 4 It can be seen that the target peak in chl0 is higher than the fusion threshold. Figure 5 As can be seen, the signals in chl1 are generally lower than the fusion threshold. This confirms that the first signal in chl0 can be used for target detection, while the first signal in chl1 is an invalid echo signal and cannot be used for target detection.

[0149] In some embodiments, due to the advantages of chirp signals such as high temporal resolution and high signal-to-noise ratio, the ultrasonic signal can be a chirp signal, that is, the echo signal is a chirp signal. For ease of description, the following description takes the chirp signal as an example.

[0150] Furthermore, in order to improve the effect of filtering and preprocessing the echo signal, the echo signal may be filtered and preprocessed in the following ways to obtain the first signal. As a possible implementation, the above step S101 performs filtering and preprocessing on the acquired echo signal to obtain the first signal includes:

[0151] The acquired echo signal is filtered and preprocessed using a preset matched filter to obtain a first signal.

[0152] The impulse response signal of the matched filter is a time-reversed signal of the transmitted signal corresponding to the echo signal.

[0153] When using chirp signals for long-distance communication and detection in ultrasonic or radar systems, the frequency modulation characteristics of chirp signals are often exploited to improve system performance. A "chirp up" signal refers to a signal whose frequency increases over time, while a "chirp down" signal refers to a signal whose frequency decreases over time. In practical applications, it is necessary to improve the system's response to specific chirp signals (chirp up or chirp down) while suppressing interference from non-target chirp signals.

[0154] A matched filter is a filter optimized to process specific signal forms. Its goal is to maximize the response to a specific signal (such as a chirp up or chirp down) while suppressing all other signals. For each chirp signal (chirp up or chirp down), a matched filter is assigned to it, matching it to the time-reverse order of the corresponding chirp. This way, when a chirp signal passes through its corresponding matched filter, the maximum output is achieved, while when an unmatched signal passes through, the output is close to zero.

[0155] The design principle of matched filters is based on maximizing the signal-to-noise ratio (SNR). For chirp signals, different matched filters are designed for "chirp up" and "chirp down" signals. The impulse response of these matched filters is the time inverse of the corresponding chirp signal.

[0156] For a matched filter with a "chirp up" signal, its impulse response is a "chirp down" signal that is time-reversed from the "chirp up" signal. When a "chirp up" signal passes through the matched filter, it will produce a maximized output because the signal matches the filter's characteristics.

[0157] For a "chirp down" signal, the impulse response of the matched filter is a "chirp up" signal, which is inversely ordered in time with the "chirp down" signal. When a "chirp down" signal passes through the matched filter, it also produces a maximized output.

[0158] The aforementioned matched filters have a natural suppressive effect on non-matched signals. For example, when a "chirp down" signal passes through a matched filter processing a "chirp up" echo signal, the output of the matched filter is significantly reduced because the direction of change of the "chirp down" signal does not match the response direction of the matched filter, effectively suppressing the "chirp down" signal. Similarly, when a "chirp up" signal passes through a matched filter processing a "chirp down" echo signal, it will also be effectively suppressed due to the low matching degree.

[0159] For example, in road detection, the ultrasonic sensor emits a "chirp-up" ultrasonic signal that gradually increases from 40kHz to 50kHz. The impulse response of the matched filter is a signal that gradually decreases from 50kHz to 40kHz. Thus, when the echo signal is a "chirp-up" signal, the matched filter can enhance it, making it stand out more clearly amidst the noise, thereby improving detection accuracy and sensitivity.

[0160] If the echo signal contains a "chirp down" signal at the same time, when the "chirp down" signal in the echo signal passes through the matched filter processing, due to poor matching, the output of the "chirp down" signal through the matched filter will be significantly reduced, thus effectively reducing the interference of the "chirp down" signal on the "chirp up" signal processing.

[0161] In this way, the target signal in the echo signal can be enhanced and the non-target signal can be suppressed by the matched filter to obtain the first signal.

[0162] For greater clarity, assume the transmitted ultrasonic signal is a linear "chirp up" signal with a frequency that increases linearly from 40kHz to 50kHz. Ideally, if this signal persists for a fixed time period, T, then at the beginning of T, the frequency is 40kHz, and at the end of T, it is 50kHz. The impulse response of the matched filter corresponding to this ultrasonic signal should be a "chirp down" signal with a frequency that decreases from 50kHz to 0kHz. This is because the maximum output in the matched filter is achieved by convolving the signal with the impulse response. Mathematically, the convolution operation involves performing a sliding multiplication of one signal with a time-reversed version of the other and integrating the result. Therefore, when the "chirp up" signal (40kHz to 50kHz) is convolved with a matched filter whose impulse response changes in frequency (i.e., the "chirp down" signal, 50kHz to 40kHz), the signal frequency and the filter frequency are aligned at every moment. During matched filter processing, when the signal and filter frequencies are perfectly aligned, their contributions at each frequency add together, forming a peak in the output signal. This peak is larger than the output of any less-than-perfectly matched signal, which greatly enhances the detectability of the signal.

[0163] Because the impulse response of a matched filter is in the reverse order of the transmitted signal, the earliest frequency (40kHz in the transmitted signal) appears last in the impulse response, and the latest frequency (50kHz in the transmitted signal) appears first. This maximizes the correlation and gain of the entire signal as it passes through the matched filter. This not only helps the signal stand out from the noise but also improves the resolution and detection accuracy of the echo signal.

[0164] Thus, in this embodiment of the present application, the acquired echo signal is filtered and preprocessed using a preset matched filter to obtain a first signal. Because the impulse response signal of the preset matched filter is the time-reversed signal of the transmitted signal corresponding to the echo signal, the matched filter uses a convolution operation to enhance the target signal, thereby optimizing the detection and recognition capabilities of the target signal and suppressing non-target signals. The matched filter can distinguish target and non-target signals, and the first signal output by the matched filter is less likely to cause crosstalk and misjudgment.

[0165] In other embodiments, step S101 performs filtering preprocessing on the acquired echo signal to obtain the first signal, including: converting the echo signal into a digital echo signal; converting the digital echo signal into a frequency domain signal; enhancing a first sub-frequency domain signal within the frequency domain signal and suppressing a second sub-frequency domain signal within the frequency domain signal to obtain a second signal; adjusting the phase of a signal within a target frequency band within the second signal to obtain a third signal; and converting the third signal into a time domain signal to obtain the first signal.

[0166] The first sub-frequency domain signal is a signal whose frequency variation pattern in the frequency domain signal is a target variation pattern, and the second sub-frequency domain signal is a signal whose frequency variation pattern in the frequency domain signal is a non-target variation pattern.

[0167] In an embodiment of the present application, in order to suppress the noise signal in the echo signal, the echo signal can be filtered in the frequency domain to obtain a first signal. Since the received echo signal is an analog signal, in order to more accurately convert the frequency domain signal, the echo signal can be first converted into a digital echo signal. The digital echo signal is converted into a frequency domain signal. The first sub-frequency domain signal in the frequency domain signal is enhanced, and the second sub-frequency domain signal in the frequency domain signal is suppressed to obtain a second signal. At this time, the target change mode can be pre-set, for example, the target change mode is pre-set as the frequency of the signal changing from the first value to the second value within the first time. At this time, the signal in the frequency domain in which the frequency of the signal changes from the first value to the second value within the first time can be determined as the first sub-frequency domain signal, and the signal of the non-target change mode in the frequency domain signal can be determined as the second sub-frequency domain signal. That is, the other frequency domain signals in the frequency domain signal except the first sub-frequency domain signal can be determined as the second sub-frequency domain signal. In this way, since the first sub-frequency domain signal is the target signal and the second sub-frequency domain signal is the noise signal, the first sub-frequency domain signal can be enhanced, for example, the amplitude value of the first sub-frequency domain signal can be enhanced, and the second sub-frequency domain signal can be suppressed, for example, the amplitude value of the second sub-frequency domain signal can be reduced, and the filtered frequency domain signal can be used as the second signal. In order to further improve the accuracy of the second signal, the phase of the signal in the target frequency band in the second signal can be adjusted so that the difference between the second signal in different frequency bands is greater, the time domain characteristics of the second signal are improved, and the second signal after phase adjustment is used as the third signal. The third signal is converted into a time domain signal to obtain the first signal.

[0168] That is, in the embodiment of the present application, after acquiring the echo signal, the echo signal can be converted into a frequency domain signal so that signals of different frequencies in the echo signal can be accurately distinguished, thereby enhancing the target signal and suppressing the non-target signal. For ease of explanation, the following description uses the chirp signal as an example.

[0169] The chirp echo signal contains target-type chirp signals and may also contain non-target-type chirp signals. The following uses the target-type chirp signal as an upsweep chirp signal, also known as the chirp up signal, as an example. In this case, it is necessary to distinguish the upsweep chirp signals reflected by different objects. The specific steps are as follows:

[0170] After receiving the echo signal, the echo signal can be converted into a digital echo signal. For example, the received analog chirp signal can be converted into a digital echo signal using an analog-to-digital converter. The digital echo signal is then converted into a frequency domain signal. In this case, a fast Fourier transform can be used to convert the digital echo signal from a time domain signal into a frequency domain signal. Of course, other methods can also be used to convert the time domain signal into a frequency domain signal, and this embodiment of the present application is not limited thereto.

[0171] The up-sweep chirp signal in the frequency domain signal is enhanced as the first sub-frequency domain signal, and the other signals in the frequency domain signal except the up-sweep chirp signal are suppressed as the second sub-frequency domain signal. For example, the signal whose frequency changes from 40kHz (kilohertz) to 50kHz in the frequency domain signal can be enhanced as the first sub-frequency domain signal, and the signal whose frequency changes from 50kHz to 40kHz can be suppressed as the second sub-frequency domain signal to obtain the second signal. The phase of the target frequency band of the second signal is adjusted using a multi-phase method to ensure that different signal sources can be effectively distinguished even in a multi-target environment to obtain a third signal, and the third signal is converted from a frequency domain signal to a time domain signal, for example, by using an inverse fast Fourier transform to convert it into a time domain signal.

[0172] This method is particularly suitable for advanced communication and detection systems that require precise control and processing of specific types of signals.

[0173] In the above process, enhancing or suppressing a specific type of chirp signal through frequency domain filtering mainly depends on converting the signal from the time domain to the frequency domain and filtering the frequency domain signal. The following details this.

[0174] When a chirp signal is acquired from a time-domain signal, it may be a set of echo signals containing multiple chirp signals from different reflectors. The time-domain signal can be converted to a frequency-domain signal. For example, this can be done using a fast Fourier transform (FFT). For ease of description, the following uses the FFT method to convert a time-domain signal to a frequency-domain signal as an example.

[0175] The Fast Fourier Transform (FFT) converts the time domain signal into the frequency domain, representing the echo signal as a superposition of frequency components within the frequency domain. After conversion to the frequency domain, the first sub-frequency domain signal within the frequency domain signal needs to be enhanced, while the second sub-frequency domain signal needs to be suppressed. This can be achieved using a digital filter. Digital filters can achieve more complex filtering characteristics, including adjustments to the signal's amplitude and phase. When setting a digital filter, the filter's frequency response is crucial, ensuring that it selectively enhances the upsweep chirp signal component while suppressing the downsweep chirp signal component.

[0176] For example, if you want to enhance a chirp-up signal whose frequency increases linearly from 40kHz to 50kHz, you can set the frequency response of the digital filter to a "passband" that increases from 40kHz to 50kHz. Within this frequency range, the digital filter can gain gain or at least maintain the original value of the signal components passing through it. For downward sweeping components, such as signals whose frequency decreases from 50kHz to 40kHz, the frequency response is set to a "stopband" that decreases from 50kHz to 40kHz, so as to reduce or suppress the signals of these frequency components.

[0177] After filtering in the frequency domain, the amplitude and phase of each frequency component of the second signal can be specifically adjusted, and the characteristics of complex numbers can be used to achieve this, thereby obtaining a third signal. For example, the phase of a specific frequency component can be delayed or advanced to further refine the signal processing strategy. For example, multi-phase technology can be used to further perform differentiated processing on signals in different frequency bands. After completing the desired frequency domain filtering processing, the third signal is converted back to a time domain signal through an inverse fast Fourier transform (IFFT) to obtain the first signal. The converted first signal will show that the up-sweep chirp signal component is enhanced, while the down-sweep chirp signal component is effectively suppressed.

[0178] Based on the above steps, it is possible to enhance specific signal types and suppress non-target signals, making the detection and processing of echo signals more effective and accurate.

[0179] For ease of implementation, the following briefly describes digital filters. Digital filters can simultaneously process both the amplitude and phase of a signal, providing more detailed signal control. Such filters are particularly important for applications that process signals with specific frequency variations, such as chirp signals.

[0180] When determining a digital filter, you first need to determine its frequency response. For a chirp-up signal (e.g., from 40kHz to 50kHz), the frequency response needs to amplify or maintain the signal within that range, while attenuating or suppressing non-target regions (e.g., regions not containing the up-sweep signal).

[0181] In some embodiments, the digital filter can modify the phase of the signal. That is, when performing frequency domain filtering on the echo signal, the phase of the signal in a specific frequency band can be further adjusted using multi-phase technology to improve the time domain characteristics of the signal.

[0182] In some embodiments, digital filters can also fine-tune the phase. In some applications, it may be necessary to fine-tune the phase of certain frequency components to optimize the final time-domain representation of the signal. This can be achieved by changing the phase response of the digital filter at these frequencies.

[0183] In some embodiments, the digital filter can also adjust the amplitude. Similarly, the amplitude of a specific frequency component can also be adjusted to match the desired signal processing effect, such as enhancing the target signal or suppressing background noise.

[0184] For example, suppose you need to process a chirp-up signal used in a road detection system. This signal increases linearly from 40kHz to 50kHz and may encounter various interferences, including down-sweep signals.

[0185] First, perform FFT conversion on the received signal to obtain its frequency domain representation. Assume that the frequency response of the digital filter increases the signal amplitude in the frequency band of 40kHz to 50kHz and suppresses the signal amplitude in other frequency bands. At the same time, the transmission characteristics of the desired signal are optimized by adjusting the phase response. In this way, the frequency domain signal can be transmitted to the digital filter, so that the digital filter can enhance the chirp up signal and suppress other non-chirp up signals to obtain the second signal. The digital filter can also adjust the phase of the signal in the target frequency band of the second signal to further enhance the signal performance or improve the system's robustness to the signal to obtain the third signal. Finally, the processed third signal is converted from a frequency domain signal back to a time domain signal to obtain the first signal.

[0186] Through such processing, the target chirp signal can be more effectively identified and processed, and the accuracy and efficiency of detection can be improved.

[0187] The design and application of digital filters enables precise control of signal components at different frequencies, including gain adjustment and suppression. This process involves specifically defining the filter's frequency response to enhance or suppress signals within a specific frequency range. The following are the steps to implement this frequency response to distinguish between up- and down-sweep chirp signals:

[0188] First, determine the frequency response: Determine the passband setting, such as increasing the chirp-up signal from 40kHz to 50kHz. This allows the digital filter to either boost or maintain signals within this frequency range, depending on the frequency response. This means the frequency response curve has a high gain value (or at least 1, indicating that the signal remains unchanged) between 40kHz and 50kHz.

[0189] Determine the stopband setting. For example, set the stopband to a frequency-reduced down-sweep signal from 50kHz to 40kHz. This allows the digital filter to suppress signals whose frequencies vary within this frequency range by applying low gain or attenuation based on the frequency response. Therefore, the frequency response is set to a low gain value in this part.

[0190] A filter design algorithm is used to determine the digital filter based on the frequency response. For example, a windowing method or optimization method (such as the Parks-McClellan algorithm) can be used to design a digital filter with specific passband and stopband frequency responses. Alternatively, a Butterworth, Chebyshev, or elliptic filter design method can be used to set the digital filter based on the desired passband and stopband specifications.

[0191] When a digital filter performs filtering on a frequency domain signal, it can multiply the frequency response by the frequency domain signature of the signal to obtain a second signal. Characteristic frequencies in the second signal are classified and phase-adjusted to further optimize the signal processing effect, thereby obtaining a third signal.

[0192] In an embodiment of the present application, although upper frequency sweep signal (chirp up) and lower frequency sweep signal (chirp down) are in the same frequency range, the variation pattern of frequency over time is different. Therefore, upper frequency sweep signal (chirp up) and lower frequency sweep signal (chirp down) can not be distinguished only by static bandpass filter or stopband filter, because static filtering cannot identify the variation pattern of signal frequency over time. It is necessary to effectively distinguish these two types of chirp signals by adopting dynamic processing technology, in combination with the time variation characteristics of frequency content. That is, in frequency domain, not only pay attention to the distribution of frequency, but also consider the variation of these frequency components over time. Such processing needs to analyze the signal in two dimensions of time-frequency, rather than simply static analysis in frequency domain.

[0193] In some embodiments, two types of chirp signals can be identified using a short-time Fourier transform (SFT). The SFT performs a fast Fourier transform on a signal within different time windows, thereby obtaining detailed information about how the signal's frequency changes over time. This detailed information is then used to identify the two types of chirp signals. In some embodiments, the SFT structure can be represented using a time-frequency graph, which allows for clear identification of the changes in different frequency components over time, thereby enabling the identification of the two types of chirp signals.

[0194] In the above time-frequency diagram, the up-sweep chirp signal appears as a linearly increasing trajectory from low frequency to high frequency, while the down-sweep chirp signal appears as a linearly decreasing trajectory from high frequency to low frequency.

[0195] In this way, specific frequency variation patterns can be identified and enhanced based on the results of the short-time Fourier transform, for example, the up-sweep signal can be enhanced, while signals of other patterns, such as the down-sweep signal, can be suppressed.

[0196] That is, a dynamic filtering region can be set in the time-frequency domain, allowing a signal to pass only when it is detected that the signal has significantly shifted from low frequency to high frequency within a specific time range. Conversely, if the signal shows the opposite frequency change pattern, it will be suppressed.

[0197] This approach allows us to identify the temporal frequency variation patterns of a signal using time-frequency analysis methods, such as the short-time Fourier transform. The key to this approach is leveraging the unique time-frequency characteristics of the signal, which are the essence of the difference between upsweep and downsweep chirp signals. This dynamic processing strategy allows us to effectively distinguish and process signals with different time-frequency variation patterns.

[0198] When using the short-time Fourier transform (STFT) or other time-frequency analysis methods, chirp-up characteristics (a change from low to high frequency) can be identified in a signal. This identification process is based on the change in the signal's frequency content over time, rather than on frequency analysis at a single point in time. This allows for the distinction between chirp-up and chirp-down signals, even though they may cover the same frequency range. At this point, the chirp-up signal has been identified, and the data can be used for inverse Fourier transform (IFFT), such as signal reconstruction. In some applications, simply identifying the signal type (for example, confirming it is a chirp-up signal) may not be sufficient. To further process or analyze the signal (such as extracting more information, removing noise, or enhancing signal quality), the signal needs to be reconstructed back to its original time domain form. The inverse Fourier transform (IFFT) is an effective method for reconstructing signals from the frequency domain to the time domain. For example, in signal filtering, even if the signal type is successfully identified through time-frequency analysis, the signal may still contain noise or other non-target components. Filters can further purify signals, enhancing the target signal and suppressing non-target components, thereby improving signal quality and system performance in subsequent processing stages. Alternatively, signal enhancement can be used: In practical applications, particularly when signal strength is weak or the signal-to-noise ratio is low, direct time-frequency analysis may not be sufficient to produce clear and reliable signal identification results. Signal enhancement using appropriate filters can improve this situation.

[0199] In this way, different types of chirp signals can be identified through the above method without interfering with each other and causing erroneous judgment, thereby improving the effectiveness of the first signal and further improving the accuracy of target detection.

[0200] As another possible implementation, the step S101 of performing filtering preprocessing on the acquired echo signal to obtain the first signal includes: performing filtering preprocessing on the acquired echo signal using a preset adaptive filtering method to obtain the first signal.

[0201] In an embodiment of the present application, an adaptive filtering method can be preset, and the acquired echo signal can be filtered using the preset adaptive filtering method. The adaptive filtering method can enhance the target signal in the echo signal and suppress the non-target signal by adjusting the filtering parameters to obtain a first signal.

[0202] In some embodiments, the preset adaptive filtering method may be a least mean squares (LMS) algorithm, a recursive least squares (RLS) algorithm, or other algorithms, which is not limited in the embodiments of the present application.

[0203] The least mean square (LMS) algorithm is a simple and widely used adaptive filtering algorithm. It adjusts filter coefficients to minimize the mean square error (MSE) between the filter output and a desired signal. The main advantages of the LMS algorithm are its simplicity of implementation and relatively low computational complexity, making it particularly suitable for applications requiring real-time processing.

[0204] The recursive least squares (RLS) algorithm is another powerful adaptive filtering algorithm that offers faster convergence and greater stability, making it particularly suitable for rapidly changing environments. While computationally more complex than the LMS algorithm, the RLS algorithm is more effective in scenarios that require rapid adaptation to signal changes.

[0205] For example, when a sonar system is used to scan a road, the emitted signal is a chirp signal whose frequency changes linearly from low to high over time. The echo signal may include signals directly reflected from obstacles or unrelated signals reflected from other objects on the ground.

[0206] The LMS algorithm can be used initially to quickly start processing the echo signal. Over time, the LMS algorithm continuously improves its response to chirp-up signals while suppressing the effects of non-target (such as chirp-down) signals by adjusting its filter coefficients in real time.

[0207] If the road environment changes significantly or the detected target moves quickly, you can switch to the RLS algorithm. Because the RLS algorithm has a faster convergence speed, it can adapt more quickly to changes in signals or environment, ensuring that the target can be accurately identified and tracked even in a changing environment.

[0208] By adjusting the adaptive filter parameters, these algorithms can "learn" and "understand" the characteristics of the reflected chirp signal in real time, dynamically optimizing the filter's performance to maximize the detection efficiency of the target signal while minimizing interference from other signals. To more clearly illustrate how to use adaptive filtering methods for echo signal preprocessing, the following uses adaptive filtering methods including the LMS algorithm and the RLS algorithm as examples.

[0209] The LMS algorithm adjusts the filter weights based on minimizing the mean square value of the output error. It is suitable for processing environments where the statistical characteristics of the signal and noise are unknown or changing. For a clearer explanation, the adaptive process of the LMS algorithm is described below:

[0210] In the initial stage, the filter's initial weights (or coefficients) can be set to preset values, such as zero or another small random number. After the ultrasonic sensor transmits a linear upsweep (chirp up) signal and receives an echo, the echo signal can be convolved with the filter's current weights to generate an output signal. The filter's output signal is compared with the desired target echo signal, and the error between the two is calculated. Using the error signal, the filter weights are updated according to the LMS algorithm. The update formula can be: the new value of the weight equals the old value plus the learning rate multiplied by the product of the input signal and the error signal. Repeat these steps until the error signal is less than the preset error threshold. The filter weights are then considered stable, meaning that the filter has adapted to the characteristics of the echo signal.

[0211] Compared with LMS, the RLS algorithm provides faster convergence speed and lower steady-state error, and is particularly suitable for signal processing in dynamic environments. For a clearer explanation, the adaptive process of the RLS algorithm is described below:

[0212] During the initialization phase, the filter's weight vector, error covariance matrix, and forgetting factor are initialized. The forgetting factor, a value close to but less than 1, determines the influence of past samples on the current estimate. After the ultrasonic sensor transmits a linear upsweep (chirp-up) signal and receives an echo, the echo signal is convolved with the filter's current weights to produce an output signal. The filter's output signal is compared with the expected target echo signal, and the error between the two is calculated. The error signal is used to update the filter weights according to the RLS algorithm. In the RLS algorithm, weight updating involves calculating a "gain" vector, which requires the inverse of the error covariance matrix. This gain is then used to adjust the weights based on the measurement error to ensure optimal adaptation. This step is repeated until the error signal falls below a preset error threshold. The filter weights are considered stable, indicating that the filter has adapted to the characteristics of the echo signal.

[0213] Since the RLS algorithm takes into account all previous samples and the forgetting factor, it can quickly adjust its weights to adapt to changes in the signal environment.

[0214] LMS and RLS adaptive filtering techniques can enhance the processing efficiency of specific chirp signals and effectively suppress non-target signals, making them widely applicable in dynamic or variable signal processing scenarios. By adjusting filter weights in real time, these methods provide powerful signal recognition and processing capabilities for sonar, radar, and other chirp-based systems.

[0215] The adaptive filtering method can identify chirp up and chirp down signals, which is less likely to cause crosstalk and misjudgment, thereby improving the accuracy of target detection.

[0216] In embodiments of the present application, adaptive filtering methods, using LMS and RLS algorithms individually or in combination, can significantly improve the processing efficiency of echo signals, such as chirp signals, particularly in dynamic or complex environments. This method enables the filter to dynamically adjust its coefficients based on the received signal, thereby achieving better adaptation to the target signal in the echo signal, namely, the specific chirp signal, and effectively suppressing non-target signals, thereby improving the accuracy and reliability of target detection.

[0217] As a possible implementation, Figure 7 As shown, the above method also includes:

[0218] Step S107: Acquire historical echo signals, and adjust the fusion threshold value based on the amplitude value information of the historical echo signals.

[0219] In an embodiment of the present application, in order to flexibly adjust the fusion threshold based on real-time environmental changes, improve adaptability to different signal characteristics, reduce false positives and false negatives in high-noise environments, and improve the accuracy and reliability of target detection, after the fusion threshold is determined, the fusion threshold can be further adjusted based on historical echo signals. Specifically, historical echo signals are obtained and the fusion threshold is adjusted based on the amplitude information of the historical echo signals to make the fusion threshold more accurate. For example, an adaptive filtering algorithm can be used to dynamically adjust the fusion threshold based on fluctuations in the amplitude information of the historical echo signals, thereby improving the accuracy of the fusion threshold.

[0220] As a possible implementation method, in order to reduce the difficulty of implementation, the echo signal is obtained by using a single snapshot method.

[0221] As a possible implementation, Figure 8 As shown, the above method also includes:

[0222] Step S108: Send a driving signal to the ultrasonic sensor.

[0223] In the embodiment of the present application, the ultrasonic sensor needs to receive a driving signal before it can transmit the ultrasonic signal. When target detection is required, a driving signal can be sent to the ultrasonic sensor to drive the ultrasonic sensor to transmit the ultrasonic signal.

[0224] Corresponding to the above embodiments, the present application also provides an ultrasonic sensor chip. This ultrasonic sensor chip employs a MIMO radar architecture. The ultrasonic sensor chip is configured to: electrically connect to an ultrasonic sensor, send a drive signal to the ultrasonic sensor to drive it to emit an ultrasonic signal; receive an echo signal generated by the ultrasonic signal; and perform target detection based on the received echo signal within a signal cycle. The ultrasonic sensor chip performs target detection by executing the target detection method described in the above embodiments.

[0225] MIMO (multiple-input-multiple-output) radar is a system technology that utilizes multiple transmitting and receiving units to improve radar performance. MIMO radar can consist of multiple transceiver units sharing a common physical platform, or multiple radar subsystems distributed across different physical locations (as long as information exchange between the systems is possible). It requires a system consisting of at least two or more transmitting or receiving units.

[0226] In this way, different radar transceiver units in the MIMO radar can form multiple observation baselines for the same target (each different signal propagation path corresponds to an observation baseline), thereby improving target detection capabilities and positioning accuracy without reducing the radar data refresh rate.

[0227] In some embodiments, the driving signal includes a Chirp signal, so that the driving signal has characteristics of high time resolution and high signal-to-noise ratio, thereby improving the accuracy and reliability of the echo signal.

[0228] In some embodiments, to increase the driving distance of the chirp signal, sending the driving signal to the ultrasonic sensor includes: increasing the duration of the chirp signal transmission based on a preset duration when sending the driving signal to the ultrasonic sensor; and / or adjusting the frequency range of the chirp signal based on the operating frequency range of the ultrasonic sensor, such that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor; and / or adjusting the transmission power of the chirp signal based on a preset power adjustment value.

[0229] That is, although chirp signals have advantages such as high temporal resolution and high signal-to-noise ratio, they have certain limitations for long-distance detection. To increase the detection range of chirp signals, the intensity of chirp signals can be increased by increasing the transmission duration of chirp signals and / or adjusting the frequency range and / or transmission power of chirp signals, thereby increasing the detection range of chirp signals. This is explained in detail below.

[0230] Increasing the duration of chirp signal transmission based on a preset duration can help improve detection range. Chirp signals, due to their time-varying frequency, can sweep across a frequency range within a certain period of time. Increasing the duration of the chirp signal increases the total energy of the signal in the propagation medium, as signal energy is directly related to its propagation time. Higher energy output helps the signal cover greater distances while maintaining sufficient strength upon reaching the receiver, enhancing signal recognition and processing capabilities, thereby increasing detection range.

[0231] For example, consider the use of chirp signals in road communications. Increasing the chirp duration from 2 milliseconds to 10 milliseconds increases the overall energy of the signal. This allows the signal to maintain a higher energy level over a longer distance, thereby increasing the effective range of signal transmission. If a 2-millisecond chirp signal previously effectively detected a target at a distance of 100 meters, increasing the signal duration could potentially extend the detection range to even greater distances, such as 200 meters or more, depending on other influencing factors such as water quality, temperature, and salinity.

[0232] And / or, the chirp signal's frequency range is adjusted based on the ultrasonic sensor's operating frequency range, so that the adjusted chirp signal's frequency range matches the ultrasonic sensor's operating frequency range. The efficiency of a chirp signal depends not only on its duration but also on its sweep range, i.e., its starting and ending frequencies. Different propagation media and ultrasonic sensors have varying frequency sensitivities. Optimizing the chirp signal's frequency range to match the ultrasonic sensor's optimal operating frequency and the medium's propagation characteristics can improve signal propagation efficiency, reduce energy loss, and thereby increase detection distance and signal-to-noise ratio.

[0233] For example, the optimal operating frequency range of ultrasonic sensors used for road detection is 40kHz to 60kHz. If the frequency range of the initial chirp signal is set to 30kHz to 80kHz, although it covers the optimal operating frequency of the ultrasonic sensor, it contains a large number of parts that exceed the optimal frequency range. These parts may suffer greater energy attenuation during the propagation process. Adjusting the frequency range of the chirp signal to more closely match the optimal operating frequency range of the ultrasonic sensor, for example, setting it to 35kHz to 65kHz, can make the signal more efficient during propagation, reduce energy loss, and facilitate achieving a longer detection distance and a higher signal-to-noise ratio. Preferably, the chirp signal is selected within the optimal operating frequency range of the ultrasonic sensor, such as 40kHz to 50kHz, 45kHz to 50kHz, 50kHz to 60kHz, etc. One approach is to select chirp up and chirp down at both ends of the center frequency (or optimal resonant frequency). For example, 50kHz is the center frequency of the ultrasonic sensor, and chirp up is selected within the optimal operating frequency range, with the highest operating frequency being the center frequency, such as 42kHz-50kHz; chirp down is selected within the optimal operating frequency range, with the highest operating frequency being the center frequency, such as 50kHz-58kHz. By selecting the optimal operating frequency range as much as possible while covering the center frequency, the highest energy can be obtained under the same driving voltage or current. Thus, by adjusting the driving frequency range, it is possible to detect farther distances when driven by a chirp signal.

[0234] In some embodiments, the continuous transmission duration of the chirp signal can be increased based on a preset duration, and the frequency range of the chirp signal can be adjusted based on the operating frequency range of the ultrasonic sensor, so that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor, thereby achieving the effect of adjusting the chirp signal to transmit over a longer distance.

[0235] In some embodiments, when increasing the duration of continuous transmission of the chirp signal based on a preset duration, the ultrasonic sensor can be driven first using a fixed-frequency driving signal of the center frequency to detect the distance of the detectable obstacle (such as the required maximum distance, such as 600 cm), and then the chirp signal can be used to drive the ultrasonic sensor to detect the distance of the detectable obstacle. If it is determined that the obstacle distance detected by the chirp signal is lower than the distance of the fixed-frequency driving signal, then in the next driving process of the chirp signal, the duration of continuous transmission of the chirp signal is increased based on the preset duration, and the distance of the detectable obstacle is continued to be determined and compared with the distance of the obstacle that can be detected by the fixed-frequency driving signal. If it is determined that the distance of the obstacle detected by the chirp signal is lower than the distance of the fixed-frequency driving signal, the duration of continuous transmission of the chirp signal is continued to be increased based on the preset duration. The above process is repeated until the distance of the obstacle that can be detected by the chirp signal is the same as or equivalent to the distance of the obstacle that can be detected by the fixed-frequency driving signal.

[0236] Furthermore, if the chirp signal is too long, it may affect the resolution or timeliness or lead to excessive power consumption. Therefore, when the continuous transmission duration of the chirp signal reaches a preset duration threshold, it can also be a benchmark for stopping the continuous transmission duration of the chirp signal. Even if this cannot achieve the same distance as the fixed frequency drive signal, it can also improve the detection distance of the chirp signal to a certain extent.

[0237] In some embodiments, when adjusting the frequency range of the chirp signal based on the operating frequency range of the ultrasonic sensor to match the adjusted frequency range of the chirp signal, the ultrasonic sensor can be driven starting from a preset frequency, the relationship between the driving frequency and the ultrasonic signal strength at that frequency recorded, and the driving frequency can be increased. Similarly, the ultrasonic signal strength corresponding to each driving frequency can be recorded. The method for detecting the relationship between the driving frequency and the ultrasonic signal strength emitted by the ultrasonic sensor can be the same for both methods. After obtaining the corresponding relationship between the frequency and the ultrasonic signal strength, the center frequency (i.e., the driving frequency with the highest ultrasonic signal strength) can be determined. Based on this relationship between the frequency and the ultrasonic signal strength, in chirp-up mode, a driving frequency of appropriate strength can be selected as the minimum driving frequency, with the minimum driving frequency serving as the starting frequency for chirp-up. The chirp-up range is defined as between the starting frequency and the center frequency. In chirp-down mode, a driving frequency of appropriate strength can be selected as the maximum driving frequency, with the maximum driving frequency serving as the cutoff frequency for chirp-down. The chirp-down range is defined as between the center frequency and the cutoff frequency. This allows for automatic frequency range adjustment, maximizing the detection distance when chirp is used as a driving signal.

[0238] In some embodiments, when the frequency range adjustment strategy and the transmission duration adjustment strategy are used simultaneously, the frequency range can be adjusted first to an optimal driving range, and then the transmission duration of the chirp signal can be adjusted. Therefore, with the combination of the two, the driving distance of the chirp signal can be greatly improved.

[0239] It should be understood that the above-mentioned preset duration can be a duration pre-set according to actual needs. The preset duration can be a fixed value, for example, 10 milliseconds, so that each time the transmission duration of the chirp signal is increased, 10 milliseconds are added. Alternatively, the preset duration can also be a variable value, for example, 10 milliseconds, 15 milliseconds, etc. In this way, when the transmission duration of the chirp signal is increased for the first time, 10 milliseconds are added, and when the transmission duration of the chirp signal is increased for the second time, 15 milliseconds are added. The preset duration can also be other values, which are not limited in the embodiments of the present application.

[0240] And / or, based on a preset power adjustment value, adjust the transmission power of the chirp signal. That is, increasing the transmission power means enhancing the energy of the ultrasonic signal while ensuring safety and compliance (for example, not exceeding relevant environmental, health and safety standards). This is achieved by increasing the input power of the ultrasonic sensor. The ultrasonic sensor converts electrical signals into mechanical vibrations (sound waves) and transmits them to the medium. Increasing the power of the input electrical signal can increase the amplitude of the sound waves generated by the ultrasonic sensor, thereby increasing the propagation distance of the sound waves in the medium, enhancing the detection capability and increasing the intensity of the reflected signal, which is particularly important for improving the distance and accuracy of target detection. The application of this method needs to take into account the possible effects of power increase, for example, exceeding a certain threshold may cause the ultrasonic sensor to overheat, or exceed the level of regulatory restrictions, etc. Therefore, the transmission power of the chirp signal can be adjusted based on the preset power adjustment value within the preset prescribed range.

[0241] It should be noted that the preset power adjustment value can be pre-set according to actual needs. The preset power adjustment value can be a fixed value, so that the transmit power of each increased chirp signal is the same value. Alternatively, the preset power adjustment value can also be a variable value. In this way, the transmit power of the chirp signal increased in the previous time can be different from the transmit power of the chirp signal increased in the next time. This embodiment of the present application is not limited to this.

[0242] In this way, the transmission parameters of the CHIP signal can be adjusted through the above method, the transmission distance of the CHIP signal can be increased, and the reliability of target detection can be improved.

[0243] As a possible implementation manner, the overlap between the frequency range of the chirp signal and the frequency range of the first chirp signal is less than a preset threshold.

[0244] The first chirp signal is a chirp signal emitted by other ultrasonic sensor chips except the ultrasonic sensor chip.

[0245] In an embodiment of the present application, there may be multiple ultrasonic sensor chips in the ultrasonic detection system. In order to reduce the crosstalk of the driving signals emitted by the multiple ultrasonic sensor chips, the overlap of the frequency ranges of the driving signals emitted by different ultrasonic sensor chips can be set to be less than a preset threshold. That is, the overlap of the frequency range of the above-mentioned chirp signal and the frequency range of the first chirp signal is less than the preset threshold. In this way, due to the effective separation of the frequency range, it is possible to ensure that the above-mentioned chirp signal and the first chirp signal are clearly separated in frequency, which can reduce interference between signals. That is, due to the different frequencies, no cancellation will occur, or even if cancellation occurs, the cancellation part is very small and does not affect the judgment of the obstacle.

[0246] The following uses the above chirp signal as the chirp up signal and the first chirp signal as the chirp down signal for illustration. Among them, the frequency range of the chirp up signal is A - B, and the frequency A is less than the frequency B. The frequency range of the chirp down signal is C - D, and the frequency C is greater than the frequency D. The frequency intervals of the chirp up signal and the chirp down chip do not overlap, or the overlap degree does not exceed a preset threshold, such as the overlap degree does not exceed 50%, or the overlap degree does not exceed 40%, or the overlap degree does not exceed 30%, or the overlap degree does not exceed 20%, or the overlap degree does not exceed 10%, or the overlap degree does not exceed 5%, etc. The preset threshold can be set according to actual needs, and the embodiments of the present application do not limit this.

[0247] In this way, it can be ensured that the chirp signals of the two ultrasonic sensors have different frequency ranges during operation. Even if they work simultaneously, due to different frequencies, there will be no cancellation situation, or even if there is a cancellation situation, the cancellation part is very small and does not affect the judgment of obstacles. This method requires adjusting and optimizing the operating frequencies of the probes and their driving systems to ensure an effective separation of the frequency ranges and ensure an obvious separation in frequency between them. By carefully selecting and adjusting the operating frequency ranges of each probe, the interference between signals can be minimized to the greatest extent. This method may require a certain degree of redesign or adjustment of the probes and the driving system to ensure an effective isolation of the frequency ranges.

[0248] The frequency range of the chirp up signal is A - B, and the frequency range of the chirp down signal is C - D. It is possible to make C B to ensure that the frequency ranges of the two do not overlap.

[0249] Each ultrasonic sensor has its resonant frequency (or center frequency). The driving frequency at the resonant frequency and the resonant frequency can maximize the energy of the ultrasonic sensor. The driving frequency of the resonant frequency makes the energy of the ultrasonic sensor smaller. Too high or too low a driving frequency setting will cause the ultrasonic sensor to fail to oscillate. Therefore, when the time span of the chirp up and chirp down signals is less than the first threshold t1, the chirp up and chirp down can be set to completely non-overlap. Preferably, both are as close to the resonant frequency as possible or near the resonant frequency. When the time span of the chirp up and chirp down signals is greater than the first threshold t1, it means that the chirp signal period is relatively long. If the chirp up and chirp down are still set to be non-overlapping, it may cause the energy of both or one of them to be lower, affecting the actual measurement effect. Therefore, when the time span of the chirp up and chirp down signals is greater than the first threshold t1, the chirp up and chirp down can be partially overlapped. For example, multiple time thresholds can be pre-set, such as a second threshold t2, a third threshold t3, and a fourth threshold t4, and frequency overlap between the chirp up and chirp down signals can be set, such as a first overlap, a second overlap, and a third overlap. When the time span between the chirp up and chirp down signals is greater than the first threshold t1 and less than the second threshold t2, the overlap between the chirp up and chirp down signals is less than or equal to the first overlap. When the time span between the chirp up and chirp down signals is greater than the second threshold t2 and less than the third threshold t3, the overlap between the chirp up and chirp down signals is less than or equal to the second overlap. When the time span between the chirp up and chirp down signals is greater than the third threshold t3 and less than the third threshold t4, the overlap between the chirp up and chirp down signals is less than or equal to the third overlap. When the time span between the chirp up and chirp down signals is greater than the nth threshold tn, the maximum overlap is used.

[0250] In this way, the overlap between the frequency range of the chirp signal and the frequency range of the first chirp signal is less than the preset threshold, which can ensure that there will be no cancellation or very little cancellation between the chirp signal and the first chirp signal, and does not affect target detection. At the same time, it does not increase the measurement cycle and can adapt to various application scenarios.

[0251] As a possible implementation, the chirp signal detection distance can be increased by adjusting the ultrasonic sensor's bandwidth. Specifically, the ultrasonic sensor chip is further configured to adjust the ultrasonic sensor's operating frequency range based on the chirp signal's frequency range, so that the adjusted chirp signal's frequency range matches the ultrasonic sensor's operating frequency range.

[0252] Because the center frequency (or resonant frequency) of a typical ultrasonic sensor is relatively fixed, it has high energy within a certain bandwidth. The higher the energy, the farther it can be transmitted, and the farther obstacles can be detected. However, the chirp signal has a wide driving frequency coverage range and cannot be well focused near the center frequency of the ultrasonic sensor. As a result, the ultrasonic sensor's energy becomes lower, and the distance to detect obstacles becomes closer. Therefore, increasing the bandwidth of the ultrasonic sensor can help improve the long-distance detection capability of the chirp signal.

[0253] In some embodiments, the bandwidth of an ultrasonic sensor can be increased to a certain extent by adjusting its resonant circuit. Ultrasonic sensors typically operate at a specific resonant frequency, which ensures their highest efficiency and sensitivity at that frequency. However, in some applications, the ultrasonic sensor may require a wider operating frequency range. By adjusting the resonant circuit, the operating bandwidth of the ultrasonic sensor can be adjusted.

[0254] The key parameters of a resonant circuit include inductance (L), capacitance (C), and impedance (R). These parameters determine the circuit's resonant frequency (f0) and quality factor (Q). The resonant frequency can be calculated using the following formula: f0 = 1 / (2π√(L*C)). Here, f0 is the resonant frequency, L is the inductance, C is the capacitance, and π is the ratio of the circumference of a circle to its circumference.

[0255] The quality factor (Q) describes sensitivity. A higher Q indicates a circuit's high selectivity near the resonant frequency and a narrower bandwidth. Conversely, a smaller Q value reduces the circuit's selectivity and increases its bandwidth. Resistor R is a key parameter influencing Q. A smaller R value indicates a higher Q. A larger R value indicates a lower Q. Therefore, increasing R can reduce Q and, in turn, increase bandwidth.

[0256] The quality factor (Q) is a parameter that measures the width of the resonant peak and, in turn, the bandwidth. Adjusting the L or C values of a circuit can change the resonant frequency, while adjusting the R value of a circuit can affect the quality factor Q, and thus the bandwidth. Increasing the circuit's impedance (R) value can reduce the Q value, thereby widening the bandwidth.

[0257] Furthermore, multiple resonant frequency designs can be used to extend the bandwidth of ultrasonic sensors. For example, by connecting different resonant circuits in parallel or series, a composite circuit with multiple resonant frequencies can be created, thereby expanding the effective operating frequency range of the ultrasonic sensor.

[0258] The relationship between the quality factor (Q) and bandwidth of a resonant circuit. A high Q value means the circuit has high selectivity near the resonant frequency, resulting in a narrower bandwidth; a low Q value means the circuit has decreased selectivity and a wider bandwidth. Adjusting the capacitor or inductor to achieve multi-frequency resonance: To expand the bandwidth, the resonant circuit can be made to resonate at multiple frequencies. This can be achieved by connecting LC circuits with different resonant frequencies in parallel or series. This method creates a complex frequency response curve that covers a wider frequency range.

[0259] Furthermore, by optimizing the ratio of C to L, a moderate increase in bandwidth can be achieved without excessively sacrificing efficiency.

[0260] For example, suppose an ultrasonic sensor operates at around 40kHz, but you want to increase its bandwidth to accommodate frequency variations within a certain range. In this case, you can appropriately increase the impedance in series or parallel with the ultrasonic sensor to reduce the system's Q factor and achieve the goal of widening the bandwidth.

[0261] Alternatively, several LC circuits with different resonant frequencies can be connected in parallel, each designed to resonate at a slightly different frequency close to 40kHz. This creates a composite circuit with good response across the entire target frequency range. Multiple switches can also be selected to match different ultrasonic sensor circuits, ensuring that different ultrasonic sensors are well tuned and the resulting resonant circuit meets the requirements of the chirp drive signal.

[0262] In some embodiments, the parameters of each LC circuit can be fine-tuned through simulation and experimentation to optimize the performance of the entire system within a target bandwidth.

[0263] It should be noted that increasing the bandwidth of ultrasonic sensors involves comprehensive consideration and optimization of the R, L, and C parameters in the circuit. It is necessary to ensure that while expanding the bandwidth, the efficiency and sensitivity requirements of practical applications can still be met.

[0264] There are generally two types of resonant circuits: parallel resonant circuits and series resonant circuits. In a parallel LC circuit, where L and C are connected in parallel, resistor R is typically connected in parallel between them. At the resonant frequency (f0) of a parallel resonant circuit, the impedances of the inductor and capacitor cancel each other, causing the input impedance of the entire circuit to reach its maximum value. Ideally (ignoring resistance or assuming it is infinite), the circuit's input impedance should be infinite at the resonant frequency. However, in reality, due to the presence of parallel resistor R, the circuit's input impedance cannot truly reach infinity. Resistor R limits the overall circuit Q (quality factor) and affects energy loss.

[0265] In a series LC circuit—one where L, C, and R are connected in series—resistor R is the portion between the inductor L and capacitor C and the power line. When a series resonant circuit resonates, the inductive impedance of the inductor and the capacitive impedance of the capacitor are equal and opposite, canceling each other out. This theoretically minimizes the total impedance of the circuit (primarily the impedance of resistor R). At the resonant frequency (f0), the circuit behaves as a purely resistive load, and ideally, without the additional resistor R, the circuit's impedance should approach zero. However, in practice, due to the presence of series resistor R, the circuit's minimum impedance is determined by R.

[0266] That is, the connection relationship between resistor R, inductor L, and capacitor C depends on whether the circuit is a series resonant circuit or a parallel resonant circuit. In a series resonant circuit, resistor R is directly connected in series with L and C. In a parallel resonant circuit, resistor R is connected in parallel with L and C. The main function of resistor R is to affect the circuit's quality factor (Q), which in turn affects the circuit's bandwidth and the height of the resonant peak, but does not change the resonant frequency (f0). Circuits with high Q values (low resistance) have sharp resonant peaks and narrow bandwidths, and are very sensitive to specific frequencies; while circuits with low Q values (high resistance) have flat resonant peaks and wide bandwidths.

[0267] That is to say, by adjusting the resistance, inductance and capacitance values of the resonant circuit, the bandwidth of the ultrasonic sensor can be improved. In addition, by setting up multiple parallel resonant circuits, a composite circuit with good response in the entire target frequency range is created, which increases the possibility of the chirp signal falling into the bandwidth, thereby improving the long-distance detection capability.

[0268] As a possible implementation, the driving signal further includes a fixed frequency driving signal. In this case, the driving signal sent to the ultrasonic sensor includes:

[0269] Send a chirp signal to the ultrasonic sensor, and when no target is detected within a first preset distance threshold, send a fixed frequency driving signal to the ultrasonic sensor. Or,

[0270] A fixed-frequency driving signal is sent to the ultrasonic sensor, and a chirp signal is sent to the ultrasonic sensor when no target is detected within a second preset distance threshold, and a fixed-frequency driving signal is sent to the ultrasonic sensor when no target is detected within a third preset distance threshold, where the second preset distance threshold is less than the third preset distance threshold.

[0271] Specifically, the fixed-frequency drive signal and chirp signal can be dynamically switched based on distance. Limited by factors such as bandwidth and resonant frequency, some degree of adjustment can improve the chirp signal's long-range detection capability. Under the same conditions, a fixed-frequency drive signal is inherently more advantageous for long-range detection. Therefore, rather than simply focusing on improving the chirp signal's long-range detection capability, the advantages of both chirp and fixed-frequency drive signals can be leveraged to detect obstacles at both near and far distances.

[0272] Chirp signals, used to drive ultrasonic sensors, offer advantages such as high resolution and strong anti-interference capabilities, making it easier for ultrasonic sensor chips to distinguish between closely spaced objects. However, fixed-frequency drive signals are susceptible to distortion caused by external interference, making it difficult to distinguish the two echo signals when two obstacles are very close. Therefore, in applications, chirp signals and fixed-frequency drive signals can be combined to determine the distance of obstacles. Closer obstacles require more accurate identification, while greater distances require less precise identification; simply knowing the presence of an obstacle is sufficient to predict the next step. However, close obstacles directly determine the subsequent response and are therefore crucial.

[0273] Based on this, a chirp signal may be sent to the ultrasonic sensor, and when no target is detected within a first preset distance threshold, a driving signal with a fixed frequency may be sent to the ultrasonic sensor.

[0274] Specifically, a chirp signal is sent to the ultrasonic sensor at a first preset distance threshold, and the chirp signal is used for close-range detection. If an obstacle is detected, the chirp signal is maintained as the driving signal for continued obstacle detection. If no object is detected within the first preset distance threshold, a fixed-frequency driving signal can be sent to the ultrasonic sensor to switch to obstacle detection.

[0275] In this way, the chirp signal has the characteristics of high resolution and strong anti-interference ability to accurately judge close-range obstacles, and the fixed frequency signal has better long-distance detection ability to preliminarily judge whether there are obstacles at a long distance, thereby ensuring accuracy while improving the long-distance and short-distance detection capabilities of the ultrasonic sensor chip.

[0276] It should be understood that the transmission distance of the chirp signal can be calculated based on the transmission speed and transmission time of the chirp signal.

[0277] Alternatively, in some embodiments, when the distance is close enough, a high speed is required. In this case, using a fixed-frequency drive signal has advantages. On the one hand, the drive speed is fast, and the signal processing speed is also fast, resulting in a faster response speed than a complex chirp signal. Because the obstacle is very close, the echo intensity of the fixed-frequency drive signal is also very large, and environmental interference has little effect on the echo. Furthermore, if a nearby vehicle or other device emits a drive signal of the same frequency, the possibility of interference is greatly reduced because these devices are relatively far away from the ultrasonic sensor. Based on this, a fixed-frequency drive signal is sent to the ultrasonic sensor. If no target is detected within a second preset distance threshold, a chirp signal is sent to the ultrasonic sensor. If no target is detected within a third preset distance threshold, a fixed-frequency drive signal is sent to the ultrasonic sensor. The second preset distance threshold is less than the third preset distance threshold.

[0278] That is, a fixed-frequency drive signal can be used first for close-range obstacle detection. That is, within the second preset distance threshold, a fixed-frequency drive signal is first sent to the ultrasonic sensor. When a target is detected within the second preset distance threshold, i.e., when an obstacle is detected within the second preset distance threshold, the fixed-frequency drive signal is continuously used for obstacle detection. If no target is detected within the second preset distance threshold, i.e., no obstacle is detected within the second preset distance threshold, a chirp signal is used for obstacle detection instead, i.e., a chirp signal is sent to the ultrasonic sensor. When using a chirp signal for obstacle detection, if an obstacle is detected within a third preset distance threshold, i.e., when a target is detected within the second preset distance threshold, the chirp signal is maintained as the drive signal for continuous obstacle detection. If no target is detected within the third preset distance threshold, i.e., when no obstacle is detected within the third preset distance threshold, a fixed-frequency drive signal is used for obstacle detection instead, i.e., a fixed-frequency drive signal is sent to the ultrasonic sensor.

[0279] In other words, a second and third preset distance thresholds are pre-set. If an obstacle is within the second preset distance threshold, a fixed-frequency drive signal is used for close-range obstacle detection. If the obstacle is outside the third preset distance threshold, a fixed-frequency drive signal is used for long-range obstacle detection. If the obstacle is between the second and third preset distance thresholds, a chirp signal is used for obstacle detection. The second preset distance threshold is a close or dangerous distance, and the third preset distance threshold is a long or safe distance. The second preset distance threshold is less than the third preset distance threshold.

[0280] In some embodiments, dynamic drive frequency adjustment can also be performed. For example, when a chirp signal is used and an obstacle is detected approaching and the distance is below a second preset distance threshold, the drive frequency will be changed to a fixed frequency drive signal for close-range obstacle detection. For another example, when a chirp signal is used and an obstacle is detected moving away and above a third preset distance threshold, the drive frequency will be changed to a fixed frequency drive signal for long-range obstacle detection.

[0281] In this way, by dynamically adjusting the driving signal, the detection of close-range, medium-range and long-range obstacles is guaranteed to a great extent, while ensuring the balance between detection precision, accuracy and distance detection characteristics.

[0282] As a possible implementation method, the chirp signal carries coding information, which can effectively reduce interference between signals.

[0283] Different chirp signals carry different coding information. In this way, when decoding the received echo signal, different chirp signals can be identified based on the decoding information, for example, whether the chirp signal is a chirp up signal or a chirp down signal, thereby effectively reducing interference between signals and the phenomenon of mutual cancellation.

[0284] The coded information carried in the chirp signal may be random code information, pseudo-random code information, or other forms of coded information, which is not limited in this embodiment of the present application.

[0285] This improves the flexibility and interference suppression capabilities of the ultrasonic sensor chip. When the coded chirp up and chirp down signals meet, the likelihood of them canceling each other out is greatly reduced, thereby improving the accuracy and reliability of target detection.

[0286] Corresponding to the above embodiment, the present application also provides an ultrasonic sensor system, such as Figure 9As shown, it includes an ultrasonic sensor 901 and an ultrasonic sensor chip 902. The ultrasonic sensor chip 902 is used to perform the target detection method described in the above embodiment. Alternatively, the ultrasonic sensor chip 902 includes the ultrasonic sensor chip described in the above embodiment.

[0287] In some embodiments, as Figure 10 As shown, the ultrasonic sensor system further includes a controller 903. Controller 903 is electrically connected to ultrasonic sensor chip 902. Controller 903 is configured to send a trigger signal to ultrasonic sensor chip 902. In response to the trigger signal, ultrasonic sensor chip 902 generates a drive signal of a specified duration and frequency and sends the drive signal to ultrasonic sensor 901. Ultrasonic sensor 901 generates an ultrasonic signal of a specified duration and frequency in response to the drive signal.

[0288] In some embodiments, the controller 903 is electrically connected to the ultrasonic sensor chip 902 via a DSI (Distributed Systems Interface). In some embodiments, the ultrasonic sensor system is further provided with a bridge chip, which is provided with a first adapter and a second adapter. The first adapter of the bridge chip is used to electrically connect to the controller 903, and the second adapter of the bridge chip is used to electrically connect to the ultrasonic sensor chip 902. The controller 903 takes care of the control functions of multiple ultrasonic sensors 901 in this system. The bridge chip can take on some of the functions of the controller 903, reducing the workload of the controller 903, thereby speeding up the operation of the entire system. The first adapter can be an SPI (Serial Peripheral Interface), UART (Universal Asynchronous Receiver / Transmitter), IIC (Inter-Integrated Circuit), LIN (Local Interconnect Network), CAN (Controller Area Network), etc. The second interface can be a DSI interface.

[0289] In some embodiments, the ultrasonic sensor 901 includes a first ultrasonic sensor and a second ultrasonic sensor, and the first ultrasonic sensor and the second ultrasonic sensor are adjacent to each other. The time interval between the time when the first ultrasonic sensor transmits the ultrasonic signal and the time when the second ultrasonic sensor transmits the ultrasonic signal is a first time length.

[0290] Ultrasonic sensor 901 includes a first ultrasonic sensor and a second ultrasonic sensor, with the first and second ultrasonic sensors positioned adjacent to each other. To reduce interference between ultrasonic signals, adjacent ultrasonic sensors can be used sequentially rather than simultaneously transmitting and receiving signals. Specifically, the time interval between the first ultrasonic sensor's transmission of an ultrasonic signal and the second ultrasonic sensor's transmission of an ultrasonic signal is a first time interval. In other words, after the first ultrasonic sensor transmits an ultrasonic signal, the second ultrasonic sensor switches to transmitting the ultrasonic signal after the first time interval has passed.

[0291] The transmission and reception of the first ultrasonic sensor and the second ultrasonic sensor may overlap for a certain period of time, or the adjacent second ultrasonic sensor may remain silent while the first ultrasonic sensor is working, and then switch to the second ultrasonic sensor for operation after the first ultrasonic sensor completes signal transmission and reception.

[0292] In one embodiment, the first duration of the interval may not be fixed but may be dynamically variable. For example, the first duration may be dynamically adjusted based on the results of a previous measurement or a preset schedule to adjust the signal transmission timing of other ultrasonic sensors, thereby optimizing the spatial distribution of the signal.

[0293] In one possible embodiment, the ultrasonic sensor 901 further includes a fifth ultrasonic sensor, and the fifth ultrasonic sensor is adjacent to the second ultrasonic sensor. In this case, the second ultrasonic sensor is located between the first and fifth ultrasonic sensors. Therefore, the second ultrasonic sensor transmits an ultrasonic signal at a time interval equal to the first and fifth ultrasonic sensors transmitting the ultrasonic signal, and the first time interval is also equal to the first time interval.

[0294] The first ultrasonic sensor and the fifth ultrasonic sensor may transmit ultrasonic signals at the same time, which can reduce the entire measurement cycle of the system.

[0295] In this way, the time interval between the time when the adjacent first ultrasonic sensor transmits the ultrasonic signal and the time interval between the second ultrasonic sensor transmits the ultrasonic signal can effectively avoid mutual interference. By introducing a time delay when the signal is transmitted, the position where the signal overlaps in the measurement area is changed or overlap is avoided, thereby improving the accuracy of the measurement.

[0296] As a possible implementation, the ultrasonic sensors 901 include multiple sensors, wherein the signal transmission angles of two adjacent ultrasonic sensors 901 are different. Alternatively, the multiple ultrasonic sensors include a first group of ultrasonic sensors and a second group of ultrasonic sensors; wherein the first group of ultrasonic sensors includes at least two third ultrasonic sensors arranged along a first direction; and the second group of ultrasonic sensors includes at least two fourth ultrasonic sensors arranged along the first direction; and the first and second groups of ultrasonic sensors are arranged along a second direction, wherein the third ultrasonic sensor in the first group of ultrasonic sensors and the fourth ultrasonic sensor in the second group of ultrasonic sensors do not overlap in the second direction, and the first direction intersects the second direction.

[0297] That is, there are multiple ultrasonic sensors 901. In some embodiments, multiple ultrasonic sensors 901 can be arranged sequentially in a preset direction. In this case, the emission angles of two adjacent ultrasonic sensors in the multiple ultrasonic sensors 901 can be set to different angles. For example, the first ultrasonic sensor is angled in the first direction, the second ultrasonic sensor is angled in the second direction, the third ultrasonic sensor is angled in the third direction, the fourth ultrasonic sensor is angled in the fourth direction... arranging multiple ultrasonic sensors in such a manner that the emission angles are set at intervals can change the difference in the echo paths of two adjacent ultrasonic sensors, thereby reducing the possibility of echoes canceling each other out at a specific location. The first direction is different from the second direction, the third direction is different from the fourth direction, and the second direction is different from the third direction.

[0298] For ease of configuration, in some embodiments, the first direction is the same as the third direction, and the second direction is the same as the fourth direction. Of course, the first, second, third, and fourth directions can all be different. That is, the signal transmission angles of two adjacent ultrasonic sensors 901 are different. The signal transmission angles of non-adjacent ultrasonic sensors 901 can be the same or different, and this is not a limitation in the present embodiment.

[0299] This can be easily achieved by setting the signal transmission angles of two adjacent ultrasonic sensors 901 to be different, and can reduce the probability of the two signals directly overlapping in a specific plane area. This configuration changes the sound wave coverage area, thereby reducing the interference and cancellation of the sound waves from the two at the same location.

[0300] And / or, when the ultrasonic sensor 901 includes multiple ultrasonic sensors, the multiple ultrasonic sensors are not completely on the same horizontal line. In this case, the multiple ultrasonic sensors include a first group of ultrasonic sensors and a second group of ultrasonic sensors. Among them, the first group of ultrasonic sensors includes at least two third ultrasonic sensors arranged along the first direction; the second group of ultrasonic sensors includes at least two fourth ultrasonic sensors arranged along the first direction. The first group of ultrasonic sensors and the second group of ultrasonic sensors are arranged along the second direction, and in the second direction, the third ultrasonic sensor in the first group of ultrasonic sensors and the fourth ultrasonic sensor in the second group of ultrasonic sensors do not overlap, and the first direction intersects with the second direction. For example, the first direction is the horizontal direction, and the second direction is the vertical direction, such as Figure 11 Of course, the first direction and the second direction may also be other directions, and the embodiment of the present application does not limit this.

[0301] Specifically, in the second direction, the third ultrasonic sensor in the first group of ultrasonic sensors is spaced apart from the fourth ultrasonic sensor in the second group of ultrasonic sensors. This creates a certain offset in the transmission paths and distances between the first and second groups of ultrasonic sensors, reducing the possibility of echo cancellation at specific locations. Furthermore, the increased spatial spacing between the ultrasonic sensors significantly reduces the possibility of echo cancellation at specific locations. This can influence the overlap of signal beams, preventing them from occurring within critical measurement areas.

[0302] Of course, the multiple ultrasonic sensors are not completely on the same horizontal line, and can be arranged in other ways, such as M-shaped arrangement, etc., which is not limited in the present embodiment.

[0303] It should be noted that the first direction may be a direction preset according to actual needs.

[0304] In this way, by changing the orientation of the ultrasonic sensors in the system and / or increasing the spatial separation of multiple ultrasonic sensors, the echo paths are made more different, thereby reducing the possibility of echoes canceling each other out at a specific location.

[0305] Those skilled in the art will clearly understand that the techniques in the embodiments of the present invention can be implemented using software plus a necessary general-purpose hardware platform. Based on this understanding, the technical solutions in the embodiments of the present invention, or the portion that contributes 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, a magnetic disk, or an optical disk, and includes a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention or certain portions of the embodiments.

[0306] In this specification, reference can be made to the same or similar parts between the various embodiments. In particular, for the device embodiment and the terminal embodiment, since they are basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description in the method embodiment.

Claims

1. A target detection method, characterized in that: include: Performing filtering preprocessing on the acquired echo signal to obtain a first signal; For each of the at least two channels, determining, at a target time, multiple access amplitude information of the first signal in the channel based on amplitude information of the first signal in the channel and other channels; The multi-access amplitude information is used to describe the validity of the first signal in the channel; determining, based on amplitude and phase values of the first signal in the other channels, multiple access mapping information of the first signal in the channels; The multiple access mapping information is used to describe amplitude and phase mapping information of the first signal between the channel and other channels; performing fusion processing on the multi-access amplitude information of the first signal on the channel and the multi-access mapping information of the first signal on the channel to obtain a fusion threshold value of a valid echo signal of the channel at the target time; Target detection is performed based on the amplitude information of the first signal in the channel and the fusion threshold value.

2. The method according to claim 1, characterized in that The determining, at the target time, based on the amplitude information of the first signal in the channel and the other channels, the multiple access amplitude information of the first signal in the channel includes: Based on the target time, determining amplitude information of the first signal in the channel and upper boundary amplitude information in other channels; Determining first amplitude threshold information based on upper boundary amplitude information of the first signal in other channels and preset echo signal ratio information between the channel and other channels; If the amplitude information of the first signal in the channel is not less than the first amplitude threshold information, the first signal is determined to be a valid echo signal, and the amplitude information of the first signal in the channel is used as the multi-access amplitude information of the first signal in the channel; or If the amplitude information of the first signal in the channel is less than the first amplitude threshold information, the first signal is determined to be an invalid echo signal, and the first preset value is used as the multi-access amplitude information of the first signal in the channel.

3. The method according to claim 1, characterized in that The determining, based on the amplitude and phase values of the first signal in the other channels, the multiple access mapping information of the first signal in the channels includes: Determining a first time based on the target time and a preset window length; determining the amplitude and phase values of the first signal in the other channels within a first time; The multiple access mapping information of the first signal in the channel is calculated according to the amplitude and phase values of the first signal in the other channels and a preset mapping relationship.

4. The method according to claim 1, wherein Also includes: Obtain threshold reference information; The fusing the multi-access amplitude information of the first signal in the channel and the multi-access mapping information of the first signal in the channel to obtain a fusion threshold value of a valid echo signal of the channel at the target time includes: The multi-access amplitude information of the first signal in the channel, the multi-access mapping information of the first signal in the channel, and the threshold reference information are fused to obtain a fusion threshold value of a valid echo signal of the channel at the target time.

5. The method according to claim 4, characterized in that The acquiring of threshold reference information includes: When the first signal is an invalid echo signal, the amplitude value information of the first signal is determined as the threshold reference information.

6. The method according to claim 1, characterized in that The filtering and preprocessing of the acquired echo signal to obtain the first signal includes: The acquired echo signal is filtered and preprocessed using a preset matched filter to obtain a first signal; wherein the impulse response signal of the matched filter is a time-reversed signal of the transmitted signal corresponding to the echo signal.

7. The method according to claim 1, characterized in that The filtering and preprocessing of the acquired echo signal to obtain the first signal includes: converting the echo signal into a digital echo signal; Converting the digital echo signal into a frequency domain signal; performing enhancement processing on a first sub-frequency domain signal in the frequency domain signal and suppressing processing on a second sub-frequency domain signal in the frequency domain signal to obtain a second signal; wherein the first sub-frequency domain signal is a signal in the frequency domain signal whose frequency change pattern is a target change pattern, and the second sub-frequency domain signal is a signal in the frequency domain signal whose frequency change pattern is a non-target change pattern; Adjusting the phase of a signal in a target frequency band in the second signal to obtain a third signal; The third signal is converted into a time domain signal to obtain the first signal.

8. The method according to claim 1, characterized in that The filtering and preprocessing of the acquired echo signal to obtain the first signal includes: The acquired echo signal is filtered and preprocessed using a preset adaptive filtering method to obtain a first signal.

9. The method according to claim 1, characterized in that Also includes: A historical echo signal is acquired, and the fusion threshold is adjusted based on amplitude value information of the historical echo signal.

10. The method according to claim 1, characterized in that The echo signal is acquired by using a single snapshot method.

11. The method according to any one of claims 1 to 10, characterized in that Also includes: Sends a driving signal to the ultrasonic sensor.

12. An ultrasonic sensor chip, characterized in that: The ultrasonic sensor chip adopts a MIMO radar structure and is used for: electrically connected to the ultrasonic sensor, and sending a driving signal to the ultrasonic sensor to drive the ultrasonic sensor to emit an ultrasonic signal; Receive an echo signal formed by an ultrasonic signal, and perform target detection based on the received echo signal within a signal cycle; wherein the ultrasonic sensor chip performs target detection by executing the target detection method according to any one of claims 1 to 11.

13. The chip according to claim 12, characterized in that The driving signal includes a chirp signal.

14. The chip according to claim 13, characterized in that The sending of a driving signal to the ultrasonic sensor comprises: When sending a driving signal to the ultrasonic sensor, increasing the duration of continuous transmission of the chirp signal based on a preset duration; and / or, adjusting the frequency range of the chirp signal based on the operating frequency range of the ultrasonic sensor, so that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor; And / or, based on a preset power adjustment value, adjusting the transmission power of the chirp signal.

15. The chip according to claim 13, characterized in that The overlap between the frequency range of the chirp signal and the frequency range of the first chirp signal is less than a preset threshold; wherein the first chirp signal is a chirp signal emitted by other ultrasonic sensor chips except the ultrasonic sensor chip.

16. The chip according to claim 13, characterized in that Also used for: Based on the frequency range of the chirp signal, the operating frequency range of the ultrasonic sensor is adjusted so that the adjusted frequency range of the chirp signal matches the operating frequency range of the ultrasonic sensor.

17. The chip according to claim 13, characterized in that The driving signal also includes a driving signal with a fixed frequency; The sending of a driving signal to the ultrasonic sensor comprises: Sending a chirp signal to the ultrasonic sensor, and when no target is detected within a first preset distance threshold, sending the fixed frequency driving signal to the ultrasonic sensor; or, The fixed-frequency driving signal is sent to the ultrasonic sensor, and when no target is detected within a second preset distance threshold, a chirp signal is sent to the ultrasonic sensor, and when no target is detected within a third preset distance threshold, the fixed-frequency driving signal is sent to the ultrasonic sensor; the second preset distance threshold is less than the third preset distance threshold.

18. The chip according to claim 13, characterized in that The chirp signal carries coded information.

19. An ultrasonic sensor system, characterized in that: include: An ultrasonic sensor and an ultrasonic sensor chip; the ultrasonic sensor chip is used to perform the target detection method according to any one of claims 1 to 11; Alternatively, the ultrasonic sensor system includes the ultrasonic sensor chip according to any one of claims 12 to 18.

20. The system according to claim 19, wherein: The ultrasonic sensor includes a first ultrasonic sensor and a second ultrasonic sensor, and the first ultrasonic sensor is arranged adjacent to the second ultrasonic sensor; The time interval between the time when the first ultrasonic sensor transmits the ultrasonic signal and the time when the second ultrasonic sensor transmits the ultrasonic signal is a first time length.

21. The system according to claim 19 or 20, characterized in that The ultrasonic sensors include a plurality of ultrasonic sensors, wherein the signal transmission angles of two adjacent ultrasonic sensors are different; And / or, the multiple ultrasonic sensors include a first group of ultrasonic sensors and a second group of ultrasonic sensors; wherein, the first group of ultrasonic sensors includes at least two third ultrasonic sensors arranged along the first direction; the second group of ultrasonic sensors includes at least two fourth ultrasonic sensors arranged along the first direction; the first group of ultrasonic sensors and the second group of ultrasonic sensors are arranged along the second direction, and in the second direction, the third ultrasonic sensor in the first group of ultrasonic sensors and the fourth ultrasonic sensor in the second group of ultrasonic sensors do not overlap, and the first direction intersects the second direction.

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