Spatial 3D modeling method based on radar microwaves

Abstract

The invention relates to microwave three-dimensional modeling, in particular to a radar microwave-based spatial 3D modeling method, which comprises the following steps of: scanning a target space by using a microwave radar, and collecting echo signals of an object in the target space; the collected echo signals are preprocessed; calculating a three-dimensional coordinate of a reflection point in the target space; performing data registration on the positions of the reflection points corresponding to the echo signals acquired in different time periods, and extracting the position, shape and size of an object in the target space; generating point cloud data of the target space according to the registered reflection point positions, and constructing a spatial three-dimensional model; according to the technical scheme provided by the invention, the defect that precise space 3D modeling cannot be realized by utilizing radar microwaves in the prior art can be effectively overcome.

Description

Technical Field

[0001] The invention relates to microwave three-dimensional modeling, and in particular to a space 3D modeling method based on radar microwaves. Background Art

[0002] With the continuous development of science and technology, 3D modeling has been widely used in various industries. Traditional 3D modeling methods usually rely on optical measurement, laser scanning and other means, but these methods have certain limitations when facing complex environments or long-distance measurements. For example, optical measurement is easily restricted by light conditions, and laser scanning may be affected by occlusion and reflection.

[0003] In order to overcome these limitations, people began to explore 3D modeling methods based on radar microwaves. Radar microwaves have the advantages of strong penetration, long measurement distance, and no restrictions on light conditions, and are particularly suitable for 3D modeling in complex environments and long distances.

[0004] However, the 3D modeling method based on radar microwaves also faces some technical challenges. First, the wavelength of radar microwaves is relatively long, resulting in relatively low measurement accuracy. Second, the echo signal of radar microwaves often contains a lot of noise and interference, which requires effective signal processing. In addition, it is also necessary to consider the impact of factors such as the parameter settings of the radar equipment, the scanning strategy, and the data processing algorithm on the modeling accuracy. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a spatial 3D modeling method based on radar microwaves, which can effectively overcome the defect of the prior art that radar microwaves cannot be used to achieve accurate spatial 3D modeling.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A spatial 3D modeling method based on radar microwaves comprises the following steps:

[0010] S1. Scan the target space using microwave radar to collect echo signals of objects in the target space;

[0011] S2, preprocessing the collected echo signal;

[0012] S3, calculating the three-dimensional coordinates of the reflection point in the target space;

[0013] S4, performing data registration on the reflection point positions corresponding to the echo signals collected at different times, and extracting the position, shape and size of the object in the target space;

[0014] S5. Generate point cloud data of the target space according to the registered reflection point positions, and construct a three-dimensional spatial model.

[0015] Preferably, in S1, scanning the target space by using a microwave radar to collect echo signals of objects in the target space includes:

[0016] S11. Setting radar operating parameters including transmission power, scanning speed and resolution according to the characteristics and needs of the target space;

[0017] S12. Perform time calibration, frequency calibration and amplitude calibration on the microwave radar;

[0018] S13. Scan the target space using microwave radar to collect echo signals of objects in the target space.

[0019] Preferably, performing time calibration, frequency calibration and amplitude calibration on the microwave radar in S12 includes:

[0020] S121, using an external synchronization signal to perform time calibration on the transmission signal and the echo signal to ensure time synchronization between the transmission signal and the echo signal;

[0021] S242, calibrating the frequencies of the transmission signal and the echo signal to ensure that they are consistent with expected values;

[0022] S243. Perform amplitude calibration on the transmission signal and the echo signal to ensure that the reflection intensity of objects at different distances can be accurately measured.

[0023] Preferably, the collected echo signal is preprocessed in S2, including:

[0024] S21, filtering the echo signal through a bandpass filter to remove noise that does not match the frequency range of the echo signal;

[0025] S22, using the Symlet wavelet function with good symmetry to perform wavelet decomposition on the filtered echo signal, and using a heuristic threshold to perform denoising;

[0026] S23, performing signal enhancement on the denoised echo signal by signal amplification to improve the amplitude and clarity of the echo signal;

[0027] S24. Time-synchronize the amplified echo signal with the transmission signal.

[0028] Preferably, performing time synchronization on the amplified echo signal and the transmission signal in S24 includes:

[0029] Set up a stable clock source to generate and synchronize the transmit and echo signals;

[0030] The phase-locked loop (PPL) is used to phase-lock the transmission signal and the echo signal to ensure that the transmission signal and the echo signal are synchronized in frequency and phase.

[0031] Preferably, calculating the three-dimensional coordinates of the reflection point in the target space in S3 includes:

[0032] S31. Establish a three-dimensional coordinate system in space to describe the position of the reflection point;

[0033] S32, calculating the distance between the reflection point and the microwave radar according to the propagation speed and time delay of the echo signal;

[0034] S33, calculating the three-dimensional coordinates of the reflection point based on the distance between the reflection point and the microwave radar and the direction information of the reflection point;

[0035] The three-dimensional coordinate system takes the microwave radar as the origin.

[0036] Preferably, in S32, calculating the distance between the reflection point and the microwave radar according to the propagation speed and time delay of the echo signal includes:

[0037] S321, determining the propagation speed of the echo signal in the medium in the target space;

[0038] S322, measuring the time delay between the transmission and reception of the echo signal;

[0039] S323. Calculate the distance between the reflection point and the microwave radar using the following formula:

[0040]

[0041] Among them, S i is the distance between reflection point i and microwave radar, v is the propagation speed of echo signal in the medium in target space, t i is the time delay between the transmission and reception of the echo signal corresponding to the reflection point i.

[0042] Preferably, in S33, the three-dimensional coordinates of the reflection point are calculated by combining the distance between the reflection point and the microwave radar and the direction information of the reflection point, including:

[0043] S331, controlling the beam scanning angle of the phased array antenna, calculating the phase difference of the collected echo signal, and determining the direction information of the reflection point according to the phase difference settlement result;

[0044] S332. Combining the distance between the reflection point and the microwave radar and the direction information of the reflection point, a trigonometric function is used to calculate the three-dimensional coordinates of the reflection point.

[0045] Preferably, in S4, data registration is performed on the reflection point positions corresponding to the echo signals collected at different times to extract the position, shape and size of the object in the target space, including:

[0046] S41, determining the position of the reference reflection point;

[0047] S42, selecting a data registration method based on feature points according to the characteristics and requirements of the echo data;

[0048] S43, selecting characteristic points of the target object in the reflection point positions corresponding to the echo signals collected at different times;

[0049] S44, calculating, according to the characteristic points of the target object, transformation parameters between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions;

[0050] S45, using transformation parameters to perform data registration between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions;

[0051] S46. Extract the position, shape and size of the object in the target space according to the registered reflection point position.

[0052] Preferably, in S5, point cloud data of the target space is generated according to the registered reflection point positions, and a spatial three-dimensional model is constructed, including:

[0053] S51, generating point cloud data of the target space according to the registered reflection point positions;

[0054] S52, gridding the point cloud data of the target space, connecting the discrete points into a continuous grid structure, and constructing a three-dimensional spatial model;

[0055] S53, performing optimization processing including smoothing, removing redundancy and filling holes on the spatial three-dimensional model;

[0056] S54, adding texture to the spatial three-dimensional model using the actually captured image or the synthesized pattern to enhance the realism and readability of the model;

[0057] S55. Render the spatial three-dimensional model after adding texture by adjusting parameters including lighting, shadow and color to obtain better visual effects.

[0058] (III) Beneficial effects

[0059] Compared with the prior art, the spatial 3D modeling method based on radar microwave provided by the present invention has the following beneficial effects:

[0060] 1) Use microwave radar to scan the target space, collect echo signals of objects in the target space, pre-process the collected echo signals, establish a three-dimensional coordinate system in the space to describe the position of the reflection point, calculate the distance between the reflection point and the microwave radar according to the propagation speed and time delay of the echo signal, and calculate the three-dimensional coordinates of the reflection point by combining the distance between the reflection point and the microwave radar and the direction information of the reflection point, so as to accurately obtain the reflection point position corresponding to the echo signals collected at different times, and provide data support for the subsequent construction of the spatial three-dimensional model;

[0061] 2) Perform data registration on the reflection point positions corresponding to the echo signals collected at different times, extract the position, shape and size of the objects in the target space, generate point cloud data of the target space according to the registered reflection point positions, and construct a three-dimensional spatial model, so that radar microwaves can be used to achieve accurate spatial 3D modeling, fully reflecting the spatial three-dimensional information of objects in closed spaces (such as indoors) and semi-enclosed spaces (such as car cockpits). BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 It is a schematic diagram of the process of the present invention;

[0064] Figure 2 It is a schematic diagram of the process of calculating the three-dimensional coordinates of the reflection point in the target space in the present invention;

[0065] Figure 3 It is a schematic diagram of the process of performing data registration on the reflection point positions corresponding to the echo signals collected at different times in the present invention. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] A spatial 3D modeling method based on radar microwaves, such as Figure 1As shown, S1, using microwave radar to scan the target space and collect echo signals of objects in the target space, specifically including:

[0068] S11. Setting radar operating parameters including transmission power, scanning speed and resolution according to the characteristics and needs of the target space;

[0069] S12. Perform time calibration, frequency calibration and amplitude calibration on the microwave radar;

[0070] S13. Scan the target space using microwave radar to collect echo signals of objects in the target space.

[0071] Specifically, S12 performs time calibration, frequency calibration and amplitude calibration on the microwave radar, including:

[0072] S121, using an external synchronization signal to perform time calibration on the transmission signal and the echo signal to ensure time synchronization between the transmission signal and the echo signal;

[0073] S242, calibrating the frequencies of the transmission signal and the echo signal to ensure that they are consistent with expected values;

[0074] S243. Perform amplitude calibration on the transmission signal and the echo signal to ensure that the reflection intensity of objects at different distances can be accurately measured.

[0075] like Figure 1 As shown, S2, preprocessing the collected echo signal, specifically including:

[0076] S21, filtering the echo signal through a bandpass filter to remove noise that does not match the frequency range of the echo signal;

[0077] S22, using the Symlet wavelet function with good symmetry to perform wavelet decomposition on the filtered echo signal, and using a heuristic threshold to perform denoising;

[0078] S23, performing signal enhancement on the denoised echo signal by signal amplification to improve the amplitude and clarity of the echo signal;

[0079] S24. Time-synchronize the amplified echo signal with the transmission signal.

[0080] Specifically, in S24, time synchronization is performed on the amplified echo signal and the transmission signal, including:

[0081] Set up a stable clock source to generate and synchronize the transmit and echo signals;

[0082] The phase-locked loop (PPL) is used to phase-lock the transmission signal and the echo signal to ensure that the transmission signal and the echo signal are synchronized in frequency and phase.

[0083] like Figure 1 and Figure 2 As shown, S3, calculating the three-dimensional coordinates of the reflection point in the target space, specifically including:

[0084] S31. Establish a three-dimensional coordinate system in space to describe the position of the reflection point;

[0085] S32, calculating the distance between the reflection point and the microwave radar according to the propagation speed and time delay of the echo signal;

[0086] S33, calculating the three-dimensional coordinates of the reflection point based on the distance between the reflection point and the microwave radar and the direction information of the reflection point;

[0087] The three-dimensional coordinate system takes the microwave radar as the origin.

[0088] 1) In S32, the distance between the reflection point and the microwave radar is calculated according to the propagation speed and time delay of the echo signal, including:

[0089] S321, determining the propagation speed of the echo signal in the medium in the target space;

[0090] S322, measuring the time delay between the transmission and reception of the echo signal;

[0091] S323. Calculate the distance between the reflection point and the microwave radar using the following formula:

[0092]

[0093] Among them, S i is the distance between reflection point i and microwave radar, v is the propagation speed of echo signal in the medium in target space, t i is the time delay between the transmission and reception of the echo signal corresponding to the reflection point i.

[0094] 2) S33 combines the distance between the reflection point and the microwave radar, as well as the direction information of the reflection point, to calculate the three-dimensional coordinates of the reflection point, including:

[0095] S331, controlling the beam scanning angle of the phased array antenna, calculating the phase difference of the collected echo signal, and determining the direction information of the reflection point according to the phase difference settlement result;

[0096] S332. Combining the distance between the reflection point and the microwave radar and the direction information of the reflection point, a trigonometric function is used to calculate the three-dimensional coordinates of the reflection point.

[0097] The above technical solution uses microwave radar to scan the target space, collect echo signals of objects in the target space, pre-process the collected echo signals, and establish a three-dimensional coordinate system in space to describe the position of the reflection point. According to the propagation speed and time delay of the echo signal, the distance between the reflection point and the microwave radar is calculated. Combined with the distance between the reflection point and the microwave radar, as well as the direction information of the reflection point, the three-dimensional coordinates of the reflection point are calculated, so that the reflection point position corresponding to the echo signals collected at different times can be accurately obtained, providing data support for the subsequent construction of a three-dimensional spatial model.

[0098] like Figure 1 and Figure 3 As shown, S4, data registration is performed on the reflection point positions corresponding to the echo signals collected at different times to extract the position, shape and size of the object in the target space, specifically including:

[0099] S41, determining the position of the reference reflection point;

[0100] S42, selecting a data registration method based on feature points according to the characteristics and requirements of the echo data;

[0101] S43, selecting characteristic points of the target object in the reflection point positions corresponding to the echo signals collected at different times;

[0102] S44, calculating, according to the characteristic points of the target object, transformation parameters between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions;

[0103] S45, using transformation parameters to perform data registration between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions;

[0104] S46. Extract the position, shape and size of the object in the target space according to the registered reflection point position.

[0105] like Figure 1 As shown, S5, generating point cloud data of the target space according to the registered reflection point positions, and constructing a spatial three-dimensional model, specifically including:

[0106] S51, generating point cloud data of the target space according to the registered reflection point positions;

[0107] S52, gridding the point cloud data of the target space, connecting the discrete points into a continuous grid structure, and constructing a three-dimensional spatial model;

[0108] S53, performing optimization processing including smoothing, removing redundancy and filling holes on the spatial three-dimensional model;

[0109] S54, adding texture to the spatial three-dimensional model using the actually captured image or the synthesized pattern to enhance the realism and readability of the model;

[0110] S55. Render the spatial three-dimensional model after adding texture by adjusting parameters including lighting, shadow and color to obtain better visual effects.

[0111] The above technical solution performs data registration on the reflection point positions corresponding to the echo signals collected at different times, extracts the position, shape and size of the objects in the target space, generates point cloud data of the target space according to the registered reflection point positions, and constructs a three-dimensional spatial model, thereby enabling accurate spatial 3D modeling using radar microwaves, fully reflecting the spatial three-dimensional information of objects in closed spaces (such as indoors) and semi-enclosed spaces (such as car cockpits).

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A spatial 3D modeling method based on radar microwaves, characterized in that: The following steps are involved: S1. Scan the target space using microwave radar to collect echo signals of objects in the target space; S2, preprocessing the collected echo signal; S3, calculating the three-dimensional coordinates of the reflection point in the target space; S4, performing data registration on the reflection point positions corresponding to the echo signals collected at different times, and extracting the position, shape and size of the object in the target space; S5. Generate point cloud data of the target space according to the registered reflection point positions, and construct a three-dimensional spatial model.

2. The method for spatial 3D modeling based on radar microwaves according to claim 1, characterized in that: S1 uses microwave radar to scan the target space and collect echo signals of objects in the target space, including: S11. Setting radar operating parameters including transmission power, scanning speed and resolution according to the characteristics and needs of the target space; S12. Perform time calibration, frequency calibration and amplitude calibration on the microwave radar; S13. Scan the target space using microwave radar to collect echo signals of objects in the target space.

3. The method for spatial 3D modeling based on radar microwaves according to claim 2, characterized in that: S12 performs time calibration, frequency calibration and amplitude calibration on microwave radar, including: S121, using an external synchronization signal to perform time calibration on the transmission signal and the echo signal to ensure time synchronization between the transmission signal and the echo signal; S242, calibrating the frequencies of the transmission signal and the echo signal to ensure that they are consistent with expected values; S243. Perform amplitude calibration on the transmission signal and the echo signal to ensure that the reflection intensity of objects at different distances can be accurately measured.

4. The method for spatial 3D modeling based on radar microwaves according to claim 1, characterized in that: In S2, the collected echo signals are preprocessed, including: S21, filtering the echo signal through a bandpass filter to remove noise that does not match the frequency range of the echo signal; S22, using the Symlet wavelet function with good symmetry to perform wavelet decomposition on the filtered echo signal, and using a heuristic threshold to perform denoising; S23, performing signal enhancement on the denoised echo signal by signal amplification to improve the amplitude and clarity of the echo signal; S24. Time-synchronize the amplified echo signal with the transmission signal.

5. The method for spatial 3D modeling based on radar microwaves according to claim 4, characterized in that: In S24, the amplified echo signal is time-synchronized with the transmission signal, including: Set up a stable clock source to generate and synchronize the transmit and echo signals; The phase-locked loop (PPL) is used to phase-lock the transmission signal and the echo signal to ensure that the transmission signal and the echo signal are synchronized in frequency and phase.

6. The method for spatial 3D modeling based on radar microwaves according to claim 1, characterized in that: S3 calculates the three-dimensional coordinates of the reflection point in the target space, including: S31. Establish a three-dimensional coordinate system in space to describe the position of the reflection point; S32, calculating the distance between the reflection point and the microwave radar according to the propagation speed and time delay of the echo signal; S33, calculating the three-dimensional coordinates of the reflection point based on the distance between the reflection point and the microwave radar and the direction information of the reflection point; The three-dimensional coordinate system takes the microwave radar as the origin.

7. The method for spatial 3D modeling based on radar microwaves according to claim 6, characterized in that: In S32, the distance between the reflection point and the microwave radar is calculated according to the propagation speed and time delay of the echo signal, including: S321, determining the propagation speed of the echo signal in the medium in the target space; S322, measuring the time delay between the transmission and reception of the echo signal; S323. Calculate the distance between the reflection point and the microwave radar using the following formula: Among them, S i is the distance between reflection point i and microwave radar, v is the propagation speed of echo signal in the medium in target space, t i is the time delay between the transmission and reception of the echo signal corresponding to the reflection point i.

8. The method for spatial 3D modeling based on radar microwaves according to claim 6, characterized in that: S33 combines the distance between the reflection point and the microwave radar, as well as the direction information of the reflection point, to calculate the three-dimensional coordinates of the reflection point, including: S331, controlling the beam scanning angle of the phased array antenna, calculating the phase difference of the collected echo signal, and determining the direction information of the reflection point according to the phase difference settlement result; S332. Combining the distance between the reflection point and the microwave radar and the direction information of the reflection point, a trigonometric function is used to calculate the three-dimensional coordinates of the reflection point.

9. The method for spatial 3D modeling based on radar microwaves according to claim 1, characterized in that: In S4, data registration is performed on the reflection point positions corresponding to the echo signals collected at different times to extract the position, shape and size of the object in the target space, including: S41, determining the position of the reference reflection point; S42, selecting a data registration method based on feature points according to the characteristics and requirements of the echo data; S43, selecting characteristic points of the target object in the reflection point positions corresponding to the echo signals collected at different times; S44, calculating, according to the characteristic points of the target object, transformation parameters between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions; S45, using transformation parameters to perform data registration between the reflection point positions corresponding to the echo signals collected at different times and the reference reflection point positions; S46. Extract the position, shape and size of the object in the target space according to the registered reflection point position.

10. The method for spatial 3D modeling based on radar microwaves according to claim 1, characterized in that: In S5, the point cloud data of the target space is generated according to the registered reflection point positions, and a spatial three-dimensional model is constructed, including: S51, generating point cloud data of the target space according to the registered reflection point positions; S52, gridding the point cloud data of the target space, connecting the discrete points into a continuous grid structure, and constructing a three-dimensional spatial model; S53, performing optimization processing including smoothing, removing redundancy and filling holes on the spatial three-dimensional model; S54, adding texture to the spatial three-dimensional model using the actually captured image or the synthesized pattern to enhance the realism and readability of the model; S55. Render the spatial three-dimensional model after adding texture by adjusting parameters including lighting, shadow and color to obtain better visual effects.

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