A method of distance detection based on echo signals

Abstract

The application provides a distance detection method based on echo signals, relates to the technical field of distance detection, and aims to realize more accurate echo-based distance measurement, and comprises the following steps: continuously sending multiple detection signals, and respectively acquiring signal strength and transmission time of the detection signals; respectively receiving echo signals of each detection signal, and respectively recording receiving time of each echo signal; performing filtering processing, acquiring an attenuation value of each echo signal according to a filtering result; calculating an estimated distance value corresponding to each detection signal according to the transmission time of the detection signal and the receiving time of the corresponding echo signal; acquiring a correction coefficient corresponding to each estimated distance value according to the attenuation value of the echo signal; and acquiring a final distance value according to the estimated distance value and the corresponding correction coefficient. The application has the advantages of higher distance measurement precision, higher reliability and simple calculation.

Description

Technical Field

[0001] This invention relates to the field of distance detection technology, and more specifically, to a distance detection method based on echo signals. Background Technology

[0002] Echo measurement refers to the measurement of echo signals by detectors mounted on a corresponding platform, such as radar, in order to obtain the required physical information.

[0003] With the development of intelligent technology, the demand for distance detection is increasing in many areas, such as autonomous driving, security monitoring, industrial automation, and equipment internal structure detection, all of which require high-precision distance monitoring. Detecting target distances by sending signals and detecting echoes is a widely used application. Generally, distance detection uses the time it takes for the echo to arrive and the propagation speed of the detection wave to determine the distance. However, this calculation alone will introduce errors because the propagation speed and other data are based on ideal values, and many factors can lead to deviations during actual propagation. Similarly, distance can be estimated based on the energy loss of the detected wave, but calculation errors still exist.

[0004] To achieve more accurate echo-based distance measurement, it is urgent to optimize the data processing methods used in echo measurement. Summary of the Invention

[0005] The purpose of this invention is to provide a distance detection method based on echo signals, which can achieve more accurate echo-based distance measurement.

[0006] The embodiments of the present invention are achieved through the following technical solutions:

[0007] A distance detection method based on echo signals includes the following steps:

[0008] Multiple detection signals g are sent continuously i And obtain the signal strength SI of the detected signal respectively. i and launch time t i i = 1, 2, ..., K, where K is the total number of detection signals sent;

[0009] The echo signal of each detection signal is received separately, and the reception time t′ of each echo signal is recorded separately. i ;

[0010] The filtering process is performed, and the attenuation value (dec) of each echo signal is obtained based on the filtering result. i ;

[0011] According to the transmission time t of the detection signal iand the corresponding reception time t′ of the echo signal i Calculate the estimated distance value S corresponding to each of the detection signals. i ;

[0012] According to the attenuation value dec of the echo signal i Obtain the correction factor α corresponding to each estimated distance value. i ;

[0013] Based on the estimated distance value S i and the corresponding correction factor α i Obtain the final distance value S * .

[0014] Preferably, the plurality of detection signals g i The signal strength and signal frequency are different.

[0015] Preferably, multiple detection signals g are sent continuously. i It sends data at equal time intervals.

[0016] Preferably, the filtering method includes bandpass filtering, high-pass filtering, and low-pass filtering.

[0017] Preferably, the attenuation value dec of each echo signal is obtained based on the filtering result. i The method includes the following steps:

[0018] Obtain the signal strength SI' of the filtered echo signal. i ;

[0019] Obtain the attenuation value dec i :

[0020] dec i =SI i -SI' i .

[0021] Preferably, the estimated distance value S corresponding to each of the detection signals is calculated. i The method is as follows:

[0022]

[0023] Where V is the propagation speed of the detection signal.

[0024] Preferably, based on the attenuation value dec of the echo signal i Obtain the correction factor α corresponding to each estimated distance value. i The method includes the following steps:

[0025] Obtain the attenuation value dec i The corresponding distance correction share hi :

[0026]

[0027] Where e is the natural constant, f i The detection signal g i The corresponding signal frequency, a, b, and c are three constant coefficients, f(S) i () represents wave diffusion attenuation;

[0028] Obtain the attenuation value dec i The corresponding correction weight P i :

[0029]

[0030] Obtain the correction coefficient α corresponding to each estimated distance value. i :

[0031]

[0032] Preferably, based on the estimated distance value S i and the corresponding correction factor α i Obtain the final distance value S * The method is as follows:

[0033]

[0034] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0035] This invention first calculates a preliminary estimated distance value S by detecting the propagation speed of the signal, the transmission time, and the reception time of the echo signal. i Based on this, further modifications are made, ensuring a solid foundation for the accuracy of the final structure.

[0036] This invention infers the propagation distance by analyzing the signal frequency and loss, and uses this value as a correction to obtain the estimated distance value S. i The reference value helps improve the accuracy and reliability of distance calculation based on echoes;

[0037] This invention allows for the selection of different detection signals to be sent at equal time intervals. This allows for the pre-setting of the transmission time of the first detection signal and the calculation of subsequent transmission times. It also reduces a recording task and simplifies the workload of the system.

[0038] This invention uses multiple sets of different detection signals for calculation and correction, which are used as references to each other to further improve the calculation accuracy;

[0039] This invention is simple in design, consumes relatively few computing resources, has a high cost-performance ratio, and is easy to promote and implement. Attached Figure Description

[0040] Figure 1 This is a flowchart illustrating a distance detection method based on echo signals provided in Embodiment 1 of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Example 1

[0043] This embodiment provides a distance detection method based on echo signals. (See attached document.) Figure 1 This includes the following steps:

[0044] Step S1: Continuously send multiple detection signals g i And obtain the signal strength SI of the detected signal respectively. i and launch time t i , i = 1, 2, ..., K, where K is the total number of detection signals sent;

[0045] Step S2: Receive the echo signal of each detection signal respectively, and record the reception time t′ of each echo signal respectively. i ;

[0046] Step S3: Perform filtering processing, and obtain the attenuation value dec for each echo signal based on the filtering result. i ;

[0047] Step S4: Based on the transmission time t of the detection signal i and the corresponding reception time t′ of the echo signal i Calculate the estimated distance value S corresponding to each of the detection signals. i ;

[0048] Step S5: Based on the attenuation value dec of the echo signal i Obtain the correction factor α corresponding to each estimated distance value. i ;

[0049] Step S6: Based on the estimated distance value S i and the corresponding correction factor α i Obtain the final distance value S * .

[0050] In this embodiment, after transmitting the detection signal, receiving the echo signal, and collecting various values, the transmission time t of the detection signal is first determined. i and the corresponding reception time t′ of the echo signal i Calculate the estimated distance value S corresponding to each of the detection signals. i Then, based on the attenuation value dec of the echo signal... i Obtain the correction factor α corresponding to each estimated distance value. i Based on this, the previously obtained estimated distance value S i Make corrections to obtain a more accurate final distance value S. * .

[0051] This setup is because distance detection is usually performed by sending a detection signal to the target. The distance is determined by the time it takes for the echo to arrive and the propagation speed of the detection wave. Alternatively, the distance can be estimated by detecting the energy loss of the final returned echo. Both of these methods are based on ideal conditions and use calculation formulas, so they will have certain errors.

[0052] Therefore, in this embodiment, the initial estimated distance is determined by the arrival time of the echo and the propagation speed of the probe wave. Multiple sets of data are collected to obtain multiple estimated distance values. The correction coefficient of each estimated distance value is used as the confidence level. The value of this correction coefficient is estimated by the energy loss of the final returned echo. Then, each estimated distance value is assigned a weight as a correction coefficient, and finally a more accurate final distance value is obtained.

[0053] This embodiment does not rely on complex algorithms or training methods to optimize the accuracy of distance measurement. While improving the accuracy and reliability of distance calculation, it also helps to save computing resources and reduce computing costs.

[0054] Example 2

[0055] This embodiment is based on the technical solution of Embodiment 1, and further explains the transmission of the detection signal and the filtering processing of the echo signal.

[0056] In this embodiment, the multiple detection signals g sent in step S1 i The signal strength and signal frequency are different.

[0057] As another preferred embodiment, in step S1, multiple detection signals g are continuously sent. i It sends data at equal time intervals.

[0058] When transmitting signals at equal time intervals, the start time of the test can be preset and recorded as the transmission time of the first detection signal g1. Alternatively, only the transmission time of the first detection signal g1 can be recorded, and the transmission times of subsequent detection signals can be calculated directly based on the transmission interval period. This reduces the amount of data that needs to be processed during the test, lowers the system workload, and prevents data reception and recording congestion and conflicts. The transmission times of other detection signals can be pre-calculated based on the preset start time of the test, or they can be calculated based on the transmission interval after the echo signal has been received.

[0059] On the other hand, in step S3, the filtering method includes bandpass filtering, high-pass filtering, and low-pass filtering.

[0060] During propagation, the detection signal will be mixed with noise, so the received echo signal will also be mixed with noise, and the signal-to-noise ratio may be very low. Therefore, directly calculating the attenuation based on this will cause a large error, so filtering is required.

[0061] In addition to traditional filtering methods, there are now many other filtering methods to choose from. For example, the filter can be designed based on wavelet decomposition to improve the filter's performance.

[0062] Compared to Fourier transform, wavelet transform has the ability to characterize the local features of a signal in both the frequency and time domains. Its core is to utilize the multi-resolution analysis characteristics of wavelets. By selecting an appropriate wavelet basis, the signal is decomposed into scale coefficients and wavelet coefficients at different scales. Appropriate thresholds and threshold functions are selected to process the wavelet coefficients, filtering out noise-dominated wavelet coefficients. Finally, wavelet reconstruction is performed to obtain the wavelet-denoised signal.

[0063] Example 3

[0064] This embodiment is based on the technical solution of Embodiment 1, and further explains the acquisition of attenuation value, correction coefficient and final distance value.

[0065] In this embodiment, the attenuation value dec of each echo signal is obtained based on the filtering result. i The method includes the following steps:

[0066] Obtain the signal strength SI' of the filtered echo signal. i ;

[0067] Obtain the attenuation value dec i :

[0068] dec i =SI i-SI' i .

[0069] As a preferred embodiment, the estimated distance value S corresponding to each detection signal is calculated. i The method is as follows:

[0070]

[0071] Where V is the propagation speed of the detection signal.

[0072] Finally, based on the attenuation value dec of the echo signal i Obtain the correction factor α corresponding to each estimated distance value. i The method includes the following steps:

[0073] Obtain the attenuation value dec i The corresponding distance correction share h i :

[0074]

[0075] Where e is the natural constant, f i The detection signal g i The corresponding signal frequency, a, b, and c are three constant coefficients, f(S) i () represents wave diffusion attenuation;

[0076] The above formula is based on the fact that attenuation generally has the following relationship with signal frequency and propagation distance d: absorption and scattering attenuation

[0077] dec i = a*logd + b*log f i +c

[0078] The above formula for diffusion attenuation varies depending on the wave type, f(S) i ) can have different values, for example:

[0079] When the wave is a plane wave, the wave intensity attenuation follows the following relationship: f(S i ) = 1;

[0080] When the wave is a cylindrical wave, the wave intensity attenuation follows the following relationship: f(S i ) = 1 / S i

[0081] When the wave is a spherical wave, the wave intensity attenuation follows the following relationship: f(S i ) = 1 / S i 2

[0082] Other wave types will not be listed here;

[0083] Therefore, based on the above formula, the distance is calculated backwards, and then compared with the initial estimated distance value S. i The difference h i Therefore, this value is used as the distance correction share h. i To obtain the correction coefficient α i α i This represents the corresponding estimated distance value S. i The reliability of the two methods is also used as a weight, meaning that the smaller the difference between the two methods, the higher the reliability and the greater the weight.

[0084] Obtain the attenuation value dec i The corresponding correction weight P i :

[0085]

[0086] Obtain the correction coefficient α corresponding to each estimated distance value. i :

[0087]

[0088] Finally, based on the estimated distance value S i and the corresponding correction factor α i Obtain the final distance value S * The method is as follows:

[0089]

[0090] The above involves recalculating based on the previously determined weights to obtain the final corrected distance value S. * .

[0091] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A distance detection method based on echo signals, characterized in that, Includes the following steps: Send multiple detection signals in succession And obtain the signal strength of the detected signal respectively. and launch time i = 1, 2, ..., K, where K is the total number of detection signals sent; The echo signal of each detection signal is received separately, and the reception time of each echo signal is recorded separately. ; The signal is filtered, and the attenuation value of each echo signal is obtained based on the filtering result. ; Based on the transmission time of the detection signal and the corresponding reception time of the echo signal Calculate the estimated distance value corresponding to each of the detection signals. ; Based on the attenuation value of the echo signal Obtain the correction factor corresponding to each estimated distance value. ; Based on the estimated distance value and corresponding correction factor Get the final distance value ; Based on the attenuation value of the echo signal Obtain the correction factor corresponding to each estimated distance value. The method includes the following steps: Obtain the attenuation value Corresponding distance correction share : ； Where e is the natural constant, The detection signal The corresponding signal frequency, where a, b, and c are three constant coefficients. For wave diffusion and attenuation; Obtain the attenuation value Corresponding correction weight : ； Obtain the correction coefficient corresponding to each estimated distance value. : 。 2. The distance detection method based on echo signals according to claim 1, characterized in that, Multiple detection signals The signal strength and signal frequency are different.

3. The distance detection method based on echo signals according to claim 2, characterized in that, Multiple detection signals are sent continuously. It sends data at equal time intervals.

4. The distance detection method based on echo signals according to claim 1, characterized in that, The filtering methods include bandpass filtering, high-pass filtering, and low-pass filtering.

5. The distance detection method based on echo signals according to claim 1, characterized in that, The attenuation value of each echo signal is obtained based on the filtering results. The method includes the following steps: Obtain the signal strength of the filtered echo signal ; Obtain the attenuation value : 。 6. The distance detection method based on echo signals according to claim 1, characterized in that, Calculate the estimated distance value corresponding to each of the detection signals. The method is as follows: ; Where V is the propagation speed of the detection signal.

7. The distance detection method based on echo signals according to claim 1, characterized in that, Based on the estimated distance value and corresponding correction factor Get the final distance value The method is as follows: 。

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