Method, device and electronic device for determining calibration coefficient of FMCW radar

Abstract

The present application relates to a method, device, electronic device and storage medium for determining the calibration coefficient of an FMCW radar, the method comprising: obtaining echo data at a plurality of preset calibration positions; based on the echo data, extracting the phase value and energy value of the received signal collected by each receiving channel from each calibration position; performing phase compensation on the phase value of each received signal, and determining the calibration coefficient corresponding to each received signal; determining an optimization problem with the goal of maximizing the combined energy after the energy coherent combination of all received signals collected from the first calibration position, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position; based on the optimization problem, determining the optimal calibration coefficient corresponding to each receiving channel. Through the present application, the problem that the FMCW radar in the related art cannot guarantee high detection performance at all positions within the detection area is solved, and the technical effect of improving the detection performance of the FMCW radar is achieved.

Description

Technical Field

[0001] The present application relates to the field of radar technology, and in particular to a method, device, electronic device and storage medium for determining a calibration coefficient of an FMCW radar. Background Art

[0002] Frequency Modulated Wave (FMCW) is a high-precision radar ranging technology. Its transmitted wave is a high-frequency continuous wave. The frequency changes with time according to the triangular wave law. The frequency of the echo received by the FMCW radar has the same change law as the transmitted frequency, both of which are triangular wave laws. The time difference of the echo signal can be used to calculate the target distance.

[0003] Due to the unsatisfactory production and processing links, there are deviations between the antenna material, feeder length, antenna position, etc. and the ideal design values. In addition, some radar products will add non-metallic panels and other obstructions to the radar's antenna unit. These factors will introduce deviations in the radar's ranging, speed, and angle measurements. Therefore, the FMCW radar needs to be calibrated before it is put into use.

[0004] In the related art, the detection values ​​of the FMCW radar are often calibrated to achieve radar calibration. For example, the FMCW radar is used to detect the distance and angle of a point target (such as a corner reflector) placed at a known relative position and relative angle, and the detection error is recorded. When the FMCW radar is used, the calibration error value of the corresponding distance and angle is compensated based on the detection value, thereby achieving the calibration of the FMCW radar.

[0005] However, in the actual application of FMCW radar, the inherent phase error of each channel of FMCW radar is also related to the coating on the surface of the antenna penetrated by electromagnetic waves and the specific position of the FMCW radar mask. Due to the uneven coating on the surface of the antenna and the material of the FMCW radar mask, when the FMCW radar is calibrated using a corner reflector at different angles, the phase calibration coefficients obtained are not the same. If the difference between the phase calibration coefficients in two directions is large, the phase calibration coefficient obtained by calibrating in any one direction will lead to a decrease in the detection performance of the FMCW radar in the other direction.

[0006] Currently, no effective solution has been proposed for the problem in related technologies that FMCW radar cannot guarantee high detection performance at all locations within the detection area. Summary of the invention

[0007] The embodiments of the present application provide a method, device, electronic device and storage medium for determining a calibration coefficient of an FMCW radar, so as to at least solve the problem in the related art that the FMCW radar cannot guarantee high detection performance at all positions within a detection area.

[0008] In a first aspect, an embodiment of the present application provides a calibration coefficient determination method for an FMCW radar, which is applied to phase calibration of an FMCW radar, wherein the FMCW radar includes multiple receiving channels, and the method includes: acquiring echo data at multiple preset calibration positions; based on the echo data, extracting a phase value and an energy value of a received signal collected by each receiving channel from each calibration position; performing phase compensation on the phase value of each received signal according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, and determining a calibration coefficient corresponding to each received signal; determining an optimization problem with the goal of maximizing the combined energy after coherent combination of the energies of all received signals collected from a first calibration position, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined based at least on the energy value of each received signal and the calibration coefficient corresponding to each received signal; based on the optimization problem, determining an optimal calibration coefficient corresponding to each receiving channel.

[0009] In some of the embodiments, with the goal of maximizing the combined energy after the energies of all received signals collected from the first calibration position are coherently combined, determining the optimization problem includes: obtaining the distance of each of the calibration positions from the FMCW radar; calibrating the energy of each received signal according to the distance between the calibration position corresponding to the received signal and the FMCW radar, and determining the energy coefficient corresponding to each received signal; determining the optimization problem according to the energy coefficient and the calibration coefficient corresponding to each received signal, with the goal of maximizing the combined energy after the energies of all received signals collected from the first calibration position are coherently combined.

[0010] In some embodiments, the optimization problem is expressed as:

[0011]

[0012] Where S is a set of optimal calibration coefficients corresponding to each receiving channel, S = (s1, s2, ..., s N ), the FMCW radar includes N receiving channels, M is the number of the calibration positions, P (i) is a set of energy coefficients corresponding to the calibration position i, X (i) is a set of calibration coefficients corresponding to the calibration position i, is the energy coefficient corresponding to the calibration position i and the receiving channel k, s k is the optimal energy coefficient corresponding to receiving channel k, is the calibration coefficient corresponding to the calibration position i and the receiving channel k, k∈{1,2,…,N}, i∈{1,2,…,M}.

[0013] In some of the embodiments, according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal, and the calibration coefficient corresponding to each received signal is determined, including: according to the first coordinate of the calibration position corresponding to the received signal in a preset spherical coordinate system, the vertical deflection angle and the horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system are determined; according to the vertical deflection angle and the horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system and the second coordinate of each receiving channel in a preset rectangular coordinate system, phase compensation is performed on the phase value of each received signal, and the calibration coefficient corresponding to each received signal is determined, wherein the spherical coordinate system and the rectangular coordinate system both take the first receiving channel preset in the FMCW radar as the origin.

[0014] In some embodiments, before acquiring echo data at multiple preset calibration positions, the method also includes: establishing the rectangular coordinate system with the first receiving antenna corresponding to the first receiving channel as the origin, the horizontal direction of the first receiving antenna as the X-axis, the vertical direction of the first receiving antenna as the Z-axis, and the normal direction of the first receiving antenna as the Y-axis; establishing the spherical coordinate system with the first receiving antenna corresponding to the first receiving channel as the origin, the length of the line between the first receiving antenna and the coordinate point as the distance r, the angle between the line and the horizontal plane XOY of the first receiving antenna as the vertical deviation angle μ, and the angle between the line and the vertical plane YOZ of the first receiving antenna as the horizontal deviation angle ν.

[0015] In some embodiments, obtaining echo data at multiple preset calibration positions includes: selecting a first coordinate point on the Y-axis, wherein the distance between the first coordinate point and the origin matches the detection distance of the FMCW radar; triggering the selection of a second coordinate point along the positive direction of the X-axis from the first coordinate point according to the effective field of view angle of the FMCW radar, wherein a line between the first coordinate point and the second coordinate point is perpendicular to the Y-axis, and placing a reflector at the second coordinate point so that the reflector faces the FMCW radar; rotating the FMCW radar around the Y-axis by multiple preset angles in a first direction to obtain echo data at multiple preset calibration positions; or rotating the reflector around the Y-axis by multiple preset angles in a second direction to obtain echo data at multiple preset calibration positions, wherein the first direction is opposite to the second direction.

[0016] In some of the embodiments, based on the echo data, extracting the phase value and energy value of the received signal collected by each receiving channel from each calibrated position includes: extracting multiple pulse signals collected by each receiving channel from each calibrated position from the echo data; determining the average value of the multiple pulse signals, and using the average value of the multiple pulse signals as the received signal collected by each receiving channel from each calibrated position; determining the phase value and energy value of each received signal.

[0017] In some of the embodiments, extracting multiple pulse signals collected by each receiving channel from each calibrated position from the echo data includes: extracting multiple pulse signals from the echo data; performing A / D sampling and fast Fourier transform based on the distance dimension on each pulse signal to obtain the distance interval corresponding to each pulse signal; determining the calibrated position and receiving channel corresponding to each pulse signal according to the distance between each calibrated position and the FMCW radar, and the distance interval and relative intensity corresponding to each pulse signal.

[0018] In a second aspect, an embodiment of the present application further provides a calibration coefficient determination device for an FMCW radar, which is applied to phase calibration of an FMCW radar, wherein the FMCW radar includes multiple receiving channels, and the device includes: an acquisition module, which is used to acquire echo data at multiple preset calibration positions; an extraction module, which is used to extract the phase value and energy value of the received signal collected by each receiving channel from each calibration position using the echo data; a compensation module, which is used to perform phase compensation on the phase value of each received signal according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, and determine the calibration coefficient corresponding to each received signal; an optimization module, which is used to determine an optimization problem with the goal of maximizing the combined energy after the energy coherent combination of all received signals collected from the first calibration position, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined at least based on the energy value of each received signal and the calibration coefficient corresponding to each received signal; an output module, which is used to determine the optimal calibration coefficient corresponding to each receiving channel based on the optimization problem.

[0019] In a third aspect, an embodiment of the present application further provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the calibration coefficient determination method of the FMCW radar as described in the first aspect above.

[0020] In a fourth aspect, an embodiment of the present application further provides a storage medium, wherein a computer program is stored in the storage medium, wherein when the computer program is executed by a processor, the method for determining the calibration coefficient of the FMCW radar as described in the first aspect above is implemented.

[0021] Compared with the related art, the calibration coefficient determination method, device, electronic device and storage medium of the FMCW radar provided in the embodiment of the present application obtain echo data at multiple preset calibration positions; based on the echo data, extract the phase value and energy value of the received signal collected by each receiving channel from each calibration position; according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal respectively, and the calibration coefficient corresponding to each received signal is determined; with the goal of maximizing the combined energy after the energy coherent combination of all received signals collected from the first calibration position, an optimization problem is determined, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined based on at least the energy value of each received signal and the calibration coefficient corresponding to each received signal; based on the optimization problem, the optimal calibration coefficient corresponding to each receiving channel is determined, which solves the problem in the related art that the FMCW radar cannot guarantee high detection performance at all positions in the detection area, and achieves the technical effect of improving the detection performance of the FMCW radar.

[0022] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 is a flow chart of a method for determining a calibration coefficient of an FMCW radar according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of a rectangular coordinate system and a spherical coordinate system according to an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of an XOZ plane coordinate system according to an embodiment of the present application;

[0027] Figure 4 is a schematic diagram of the layout of the reflector according to an embodiment of the present application;

[0028] Figure 5is a line graph of the calibration coefficient and the optimal calibration coefficient of the FMCW radar at different calibration positions according to an embodiment of the present application;

[0029] Figure 6 It is a schematic diagram of the detection effect of the FMCW radar in the related art;

[0030] Figure 7 is a schematic diagram of the detection effect of an FMCW radar in the related art after adopting the calibration coefficient determination method according to an embodiment of the present application;

[0031] Figure 8 is a structural block diagram of a calibration coefficient determination device for an FMCW radar according to an embodiment of the present application;

[0032] Fig. 9 is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means, and should not be understood as insufficient contents disclosed in the present application.

[0034] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0035] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to greater than or equal to two. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can represent: A exists alone, A and B exist at the same time, and B exists alone. The terms "first", "second", "third" and the like involved in the present application are merely used to distinguish similar objects and do not represent a specific ordering of the objects.

[0036] This embodiment provides a method for determining a calibration coefficient of an FMCW radar, which is applied to phase calibration of an FMCW radar. The FMCW radar includes N receiving channels. Figure 1 is a flow chart of a method for determining a calibration coefficient of an FMCW radar according to an embodiment of the present application, such as Figure 1 As shown, the method includes:

[0037] Step S101, acquiring echo data at a plurality of preset calibration positions.

[0038] In this embodiment, M calibration positions can be selected in an open environment, and a reflector (such as a radar corner reflector) can be set at each calibration position. The FMCW radar can be installed on a turntable, and the relative position of the FMCW radar and the reflector can be adjusted. The echo data within a period of time can be collected by controlling the rotation of the turntable.

[0039] Step S102: extracting the phase value and energy value of the received signal collected by each receiving channel from each calibrated position based on the echo data.

[0040] In this embodiment, the echo data includes multiple pulse signals. The output of the analog to digital converter (ADC) corresponding to each FMCW pulse signal can be sampled, and a fast Fourier transform (FFT) can be performed based on the distance dimension to determine the calibration position and receiving channel corresponding to each pulse signal, thereby extracting the phase value and energy value of the receiving signal collected by each receiving channel from each calibration position.

[0041] Step S103 , according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal, and a calibration coefficient corresponding to each received signal is determined.

[0042] In this embodiment, a rectangular coordinate system and a spherical coordinate system can be established with the first receiving antenna corresponding to the preset first receiving channel as the origin. Since there are slight differences in the distances between the echo data and the antenna units of each receiving channel, the vertical deflection and horizontal deflection of the calibrated position relative to the origin are determined according to the coordinates of the calibrated position corresponding to the received signal in the spherical coordinate system. Based on the vertical deflection and horizontal deflection of the calibrated position relative to the origin and the coordinates of the receiving channel corresponding to the received signal in the rectangular coordinate system, the phase difference of each receiving channel caused by the spatial deflection is corrected to obtain the calibration coefficient corresponding to the calibration of each received signal.

[0043] Step S104, with the goal of maximizing the combined energy after coherent combination of the energies of all received signals collected from the first calibration position, determines an optimization problem, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined based at least on the energy value of each received signal and the calibration coefficient corresponding to each received signal.

[0044] Step S105 , based on the optimization problem, determining the best calibration coefficient corresponding to each receiving channel.

[0045] In this embodiment, after the above steps S101 to S103, each calibration position can obtain a set of phase calibration coefficients. And a set of energy values according to A set of energy coefficients are calculated

[0046] According to {X (i) ,P (i)} Calculate a set of optimal calibration coefficients S = (s1, s2, ..., s N) to maximize the minimum value of the combined energy after the coherent combination of the receiving channels, that is, to maximize the signal energy after the coherent combination at the worst calibration position, and use the optimal calibration coefficient to perform phase calibration on the detection value of the FMCW radar, so as to ensure that the detection performance of the FMCW radar can still reach the best at the worst calibration position, thereby enabling the FMCW radar to obtain good detection performance in all directions and positions within the entire detection area.

[0047] Through the above steps S101 to S105, the echo data at multiple preset calibration positions are obtained; based on the echo data, the phase value and energy value of the received signal collected by each receiving channel from each calibration position are extracted; according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, the phase value of each received signal is phase compensated respectively, and the calibration coefficient corresponding to each received signal is determined; with the goal of maximizing the combined energy after the energy coherent combination of all the received signals collected from the first calibration position, an optimization problem is determined, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined at least based on the energy value of each received signal and the calibration coefficient corresponding to each received signal; based on the optimization problem, the optimal calibration coefficient corresponding to each receiving channel is determined. By collecting echo data at multiple calibration positions within the detection area of ​​the FMCW radar, and calculating the phase calibration coefficient corresponding to each calibration position and each receiving channel, the optimal calibration coefficient corresponding to each receiving channel is calculated based on the calibration coefficient of each receiving channel at all calibration positions, so that the FMCW radar can obtain good detection performance in all directions and positions within the entire detection area. Through this application, the problem that the FMCW radar in the related art cannot guarantee high detection performance at all positions within the detection area is solved, and the technical effect of improving the detection performance of the FMCW radar is achieved.

[0048] In some embodiments, with the goal of maximizing the combined energy after coherent combination of the energies of all received signals collected from the first calibration position, determining the optimization problem is implemented by the following steps:

[0049] Step 1: Get the distance of each calibration position from the FMCW radar.

[0050] Step 2: According to the distance between the calibration position corresponding to the received signal and the FMCW radar, the energy of each received signal is calibrated and the energy coefficient corresponding to each received signal is determined.

[0051] Step 3: Determine the optimization problem based on the energy coefficient and calibration coefficient corresponding to each received signal, with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position are coherently combined.

[0052] In this embodiment, due to the error in the relative position of the reflector (such as the radar corner reflector) and the FMCW radar, and the inconsistency of the receiving antenna of the FMCW radar in various directions, the total energy of the received signals of each receiving channel in various directions is inconsistent. Therefore, it is necessary to calibrate the energy of each received signal.

[0053] In this embodiment, the average energy value (i.e., average energy intensity) of the received signal at each calibration position is The distance between the reflector set at each calibration position and the FMCW radar is r (i) , the energy coefficient of the received signal at each calibration position is

[0054] In the above embodiment, energy calibration includes four cases:

[0055] Assuming that the energy of the received signal collected by each receiving channel from each calibration position is the same, you can set That is, only the phase consistency is considered during the calibration process.

[0056] Assuming that the energy of the echo data obtained by the FMCW radar from each calibration position is only proportional to the distance r (i) When the energy distribution of the received signal collected by each receiving channel from each calibration position is uneven, the Q (i) P (i) The normalization is performed as follows:

[0057]

[0058] Assuming that the receiving antenna of the FMCW radar obtains the total energy of the received signal from each direction and the distance r (i) , and the relative angle between the FMCW radar and each calibration position. At the same time, when the energy distribution of the received signal collected by each receiving channel from each calibration position is uniform, it can be based on Q (i) P (i) The normalization is performed as follows:

[0059]

[0060] Assuming that the sum of the energy of the received signal acquired by the receiving antenna of the FMCW radar from each direction and the energy distribution of the received signal collected by each receiving channel from each calibration position are related to the relative angle between the FMCW radar and each calibration position, and the experimental data error is small, the average energy of the received signal collected by each receiving channel after compensating for the distance loss can be directly used as the energy coefficient, that is:

[0061]

[0062] In some of these embodiments, the optimization problem is expressed as:

[0063]

[0064]

[0065] Where S is a set of optimal calibration coefficients corresponding to each receiving channel, S = (s1, s2, ..., s N ), the FMCW radar includes N receiving channels, M is the number of calibration positions, P (i) is a set of energy coefficients corresponding to the calibration position i, X (i) is a set of calibration coefficients corresponding to the calibration position i, is the energy coefficient corresponding to the calibration position i and the receiving channel k, s k is the optimal energy coefficient corresponding to receiving channel k, is the calibration coefficient corresponding to the calibration position i and the receiving channel k, k∈{1,2,…,N}, i∈{1,2,…,M}.

[0066] In this embodiment, given P (i) and X (i) When E(P (i) ,X (i) ,S) achieves its maximum value when the following conditions are met: for any k∈{1,2,…,N},

[0067] In this embodiment, the gradient ascent method can be used to solve the above optimization problem:

[0068] Given {X (i) ,P (i)}, define the minimum energy function as:

[0069]

[0070] Among them, F(S) is about each component s in S k The derivative of is:

[0071]

[0072] Among them, l∈{1,2,…,N}, i′ is the coefficient group number that minimizes the energy function, that is:

[0073]

[0074] We can use the variable t=0,1,2,… to represent the number of iterations, and for any k∈{1,2,…,N}, we have:

[0075] s k [0] = 0;

[0076] In this embodiment, the iteration may include the following steps:

[0077] Step 1, calculate the coefficient group number i′ that minimizes the energy function:

[0078]

[0079] Step 2: Calculate F(S) with respect to each component s in S k The derivative of :

[0080]

[0081] Step 3, Update s k :

[0082]

[0083] Among them, η is the preset learning rate, and the iteration can be terminated when one of the following conditions is met:

[0084] Termination condition 1: The update of S tends to be stable, that is,

[0085]

[0086] in, A preset positive real number.

[0087] Termination condition 2: reaching the preset maximum number of iterations T.

[0088] In the above embodiment, after obtaining the optimal calibration coefficient S=S[t], parameter checking is required. If the following conditions are met:

[0089] and

[0090] The calibration is determined to be successful, and the optimal calibration coefficient S = S[t] is output, where η0∈(0,1) and η1∈1, +∞) are preset proportional thresholds; otherwise, the calibration is determined to have failed, and the operator is required to re-collect the calibration data or check whether the equipment is normal. By calculating the optimal calibration coefficient corresponding to each receiving channel, the FMCW radar can obtain good detection performance in all directions and positions within the entire detection area.

[0091] Figure 2 is a schematic diagram of a rectangular coordinate system and a spherical coordinate system according to an embodiment of the present application, such as Figure 2 As shown, in some embodiments, a rectangular coordinate system can be established with the first receiving antenna corresponding to the first receiving channel as the origin, the horizontal direction of the first receiving antenna as the X-axis, the vertical direction of the first receiving antenna as the Z-axis, and the normal direction of the first receiving antenna as the Y-axis; a spherical coordinate system can be established with the first receiving antenna corresponding to the first receiving channel as the origin, the length of the line between the first receiving antenna and the coordinate point as the distance r, the angle between the line and the horizontal plane XOY of the first receiving antenna as the vertical deflection angle μ, and the angle between the line and the vertical plane YOZ of the first receiving antenna as the horizontal deflection angle v.

[0092] like Figure 2 As shown, G is the target to be measured, the length of the line OG between the first receiving antenna and the target to be measured is taken as the distance r, the angle ∠GOB between the line OG and the horizontal plane XOY of the first receiving antenna is taken as the vertical deflection angle μ, and the angle ∠GOH between the line OG and the vertical plane YOZ of the first receiving antenna is taken as the horizontal deflection angle v.

[0093] In this embodiment, given the second coordinate (x, y, z) of a calibrated position in the rectangular coordinate system, the first coordinate (r, μ, ν) of the calibrated position in the spherical coordinate system can be obtained by the following formula:

[0094]

[0095] Similarly, given the first coordinates (r, μ, ν) of a calibration position in the spherical coordinate system, the second coordinates (x, y, z) of the calibration position in the rectangular coordinate system can be obtained by the following formula:

[0096]

[0097] In some of the embodiments, according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal, and the calibration coefficient corresponding to each received signal is determined by the following steps:

[0098] Step 1: According to the first coordinate of the calibration position corresponding to the received signal in the preset spherical coordinate system, the vertical deflection angle and the horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system are determined respectively.

[0099] Step 2: According to the vertical deflection angle and horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system and the second coordinate of each receiving channel in the preset rectangular coordinate system, phase compensation is performed on the phase value of each received signal, and the calibration coefficient corresponding to each received signal is determined, wherein both the spherical coordinate system and the rectangular coordinate system take the first receiving channel preset in the FMCW radar as the origin.

[0100] In this embodiment, the vertical deflection angle μ of each calibration position relative to the origin of the spherical coordinate system can be determined according to the first coordinate of the calibration position corresponding to the received signal in the preset spherical coordinate system. (i) and horizontal deflection angle v (i) , thereby correcting the phase difference of each receiving channel caused by the spatial deflection angle.

[0101] Figure 3 is a schematic diagram of the XOZ plane coordinate system according to an embodiment of the present application, such as Figure 3 As shown, you can use It represents the coordinates of the receiving antenna corresponding to the receiving channel k on the horizontal plane XOZ in the rectangular coordinate system. After compensating the phase difference of each channel introduced by the spatial deflection angle, the calibration coefficient of the receiving channel k at the calibration position i can be obtained:

[0102]

[0103] In some embodiments, obtaining echo data at a plurality of preset calibration positions is achieved by the following steps:

[0104] Step 1: Select a first coordinate point on the Y axis, wherein the distance between the first coordinate point and the origin matches the detection distance of the FMCW radar.

[0105] Step 2: According to the effective field of view of the FMCW radar, a second coordinate point is selected from the first coordinate point along the positive direction of the X-axis, wherein the line between the first coordinate point and the second coordinate point is perpendicular to the Y-axis, and a reflector is placed at the second coordinate point so that the reflector faces the FMCW radar.

[0106] Step 3: rotate the FMCW radar around the Y axis by multiple preset angles in a first direction to obtain echo data at multiple preset calibration positions; or rotate the reflector around the Y axis by multiple preset angles in a second direction to obtain echo data at multiple preset calibration positions, wherein the first direction is opposite to the second direction.

[0107] Figure 4 is a schematic diagram of the layout of the reflector 41 according to an embodiment of the present application, such as Figure 4 As shown, in this embodiment, the reflector 41 can be a radar corner reflector 41. First, the normal direction of the first receiving antenna (ie, the origin) is found, that is, Figure 2 In the Y-axis, a first coordinate point C is selected on the Y-axis, and the length of the line segment OC |OC| should be as long as possible or match the detection distance of the FMCW radar 40.

[0108] On the horizontal plane XOY of the first receiving antenna, a second coordinate point G can be selected from point C along the positive direction of the X axis according to the effective field of view angle α of the FMCW radar 40, so that CG is perpendicular to the Y axis. The corner reflector 41 is placed at point G, facing the FMCW radar 40 .

[0109] Finally, the FMCW radar 40 can be rotated around the Y axis in a first direction by a preset angle β (i) The first direction may be counterclockwise, or equivalently, the line segment CG where the corner reflector 41 is located is rotated around the Y axis by a preset angle β in the second direction. (i) , where the first direction is counterclockwise and the second direction is clockwise, the coordinates (x (i) ,y (i) ,z (i) ) can be calculated by the following formula:

[0110]

[0111] N preset angles β can be selected (1) , β (2) , …, β (N) The operator rotates the installation plane of the FMCW radar 40 or the corner reflector 41, or the stepper motor controls the installation plane of the FMCW radar 40 or the corner reflector 41 to rotate, and obtains echo data at multiple preset calibration positions.

[0112] In some embodiments, based on the echo data, extracting the phase value and energy value of the received signal collected by each receiving channel from each calibration position is achieved by the following steps:

[0113] Step 1: extract multiple pulse signals collected by each receiving channel from each calibration position from the echo data.

[0114] Step 2: determine an average value of the multiple pulse signals, and use the average value of the multiple pulse signals as the receiving signal collected by each receiving channel from each calibration position.

[0115] Step 3: Determine the phase value and energy value of each received signal.

[0116] In this embodiment, extracting multiple pulse signals collected by each receiving channel from each calibration position from the echo data includes: extracting multiple pulse signals from the echo data; performing A / D sampling and fast Fourier transform based on the distance dimension on each pulse signal to obtain the distance interval corresponding to each pulse signal; determining the calibration position and receiving channel corresponding to each pulse signal according to the distance between each calibration position and the FMCW radar, and the distance interval and relative intensity corresponding to each pulse signal.

[0117] In the above embodiment, it is possible to use It represents the pulse signal collected by the receiving channel k corresponding to the nth pulse at the ith calibration position, and a total of N s pulses. Among them, the calibration position number i = 1, 2, ..., M, the channel number k = 1, 2, ..., N, and the pulse number n = 1, 2, ..., N s .

[0118] First determine the average value of the pulse signal collected at each calibration position:

[0119] and will As the received signal collected by receiving channel k from the calibration position i, the energy value (energy intensity) of the received signal collected by receiving channel k from the calibration position i is recorded:

[0120] The operator |x| represents the modulus of the complex number x. and Respectively represent the real and imaginary parts of the complex number x.

[0121] And record the phase value of the received signal collected by receiving channel k from calibration position i:

[0122] Among them, the function atan2(y,x) is the four-quadrant inverse tangent function:

[0123] Figure 5 is a line chart of the calibration coefficient and the optimal calibration coefficient of the FMCW radar at different calibration positions according to an embodiment of the present application, such as Figure 5 As shown in the figure, the calibration coefficients obtained by the FMCW radar at the eight calibration positions are not the same. If the FMCW radar is calibrated according to the calibration coefficient obtained at a certain calibration position, the detection performance of the FMCW radar at the calibration position can indeed reach the best. However, at other calibration positions where the calibration coefficients corresponding to the calibration position are significantly different, the detection performance of the FMCW radar will be significantly reduced.

[0124] like Figure 5 As shown, Figure 5 The echo data of the 8 calibration positions in the image are collected by placing a corner reflector at a distance of 2 meters (y=2) and α=30° from the FMCW radar, and rotating the FMCW radar by 45 degrees each time, that is, β (i) =(i-3)×45°, where i=1,2,…,8. 15 seconds of echo data are collected at each calibration position to calculate the calibration coefficient. The calibration process does not exceed 3 minutes. The calibration coefficient of each receiving channel at all calibration positions can be used to calculate the optimal calibration coefficient for each receiving channel conveniently and quickly, so that the FMCW radar can obtain good detection performance in all directions and positions within the entire detection area.

[0125] Figure 6 It is a schematic diagram of the detection effect of FMCW radar in the related technology, such as Figure 6 As shown, the FMCW radar in the related art is often calibrated only at the exact center position. Near the third quadrant of the XOZ plane at the center of the FMCW radar's receiving antenna, the detection performance of the FMCW radar is poor and it is difficult to form an effective detection point. Figure 6 The following figure shows the detection results of three consecutive frames of FMCW radar in the related technology. The detection target moves from right to left (towards the negative half axis of the Z axis). Figure 6 It can be seen from the figure that the FMCW radar quickly lost the detected target after it entered the third quadrant.

[0126] Figure 7 FIG. 1 is a schematic diagram of the detection effect of an FMCW radar in the related art after adopting the calibration coefficient determination method according to an embodiment of the present application, such as Figure 7 As shown, when the FMCW radar in the related art adopts the same signal processing software, the calibration coefficient determination method provided in the embodiment of the present application is used to determine the optimal calibration coefficient, and the FMCW radar is calibrated based on the optimal calibration coefficient. The FMCW radar can stably detect the detection target in the third quadrant of the XOZ plane where the detection target is easily lost.

[0127] The calibration coefficient determination method provided in the embodiment of the present application collects echo data at multiple calibration positions within the detection area of ​​the FMCW radar, and calculates the phase calibration coefficient corresponding to each calibration position and each receiving channel, and calculates the optimal calibration coefficient corresponding to each receiving channel based on the calibration coefficient of each receiving channel at all calibration positions, so that the FMCW radar can obtain good detection performance in all directions and positions within the entire detection area. Through this application, the problem that the FMCW radar in the related art cannot guarantee high detection performance at all positions within the detection area is solved, and the technical effect of improving the detection performance of the FMCW radar is achieved.

[0128] This embodiment provides a calibration coefficient determination device for an FMCW radar, which is applied to phase calibration of an FMCW radar. The FMCW radar includes a plurality of receiving channels. Figure 8 is a structural block diagram of a calibration coefficient determination device for an FMCW radar according to an embodiment of the present application, such as Figure 8 As shown, the device includes: an acquisition module 80, which is used to acquire echo data at multiple preset calibration positions; an extraction module 81, which is used to extract the phase value and energy value of the received signal collected by each receiving channel from each calibration position using the echo data; a compensation module 82, which is used to perform phase compensation on the phase value of each received signal according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, and determine the calibration coefficient corresponding to each received signal; an optimization module 83, which is used to determine the optimization problem with the goal of maximizing the combined energy after the energy coherent combination of all the received signals collected from the first calibration position, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined at least based on the energy value of each received signal and the calibration coefficient corresponding to each received signal; an output module 84, which is used to determine the optimal calibration coefficient corresponding to each receiving channel based on the optimization problem.

[0129] In some of the embodiments, the optimization module 83 is further configured to obtain the distance between each calibration position and the FMCW radar; perform energy calibration on the energy of each received signal according to the distance between the calibration position corresponding to the received signal and the FMCW radar, and determine the energy coefficient corresponding to each received signal; and determine the optimization problem according to the energy coefficient and calibration coefficient corresponding to each received signal with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position are coherently combined.

[0130] In some of these embodiments, the optimization problem is expressed as:

[0131]

[0132]

[0133] Where S is a set of optimal calibration coefficients corresponding to each receiving channel, S = (s1, s2, ..., s N ), the FMCW radar includes N receiving channels, M is the number of calibration positions, P (i) is a set of energy coefficients corresponding to the calibration position i, X (i) is a set of calibration coefficients corresponding to the calibration position i, is the energy coefficient corresponding to the calibration position i and the receiving channel k, sk is the optimal energy coefficient corresponding to receiving channel k, is the calibration coefficient corresponding to the calibration position i and the receiving channel k, k∈{1,2,…,N}, i∈{1,2,…,M}.

[0134] In some of the embodiments, the compensation module 82 is further configured to determine the vertical deflection angle and horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system according to the first coordinate of the calibration position corresponding to the received signal in the preset spherical coordinate system; perform phase compensation on the phase value of each received signal according to the vertical deflection angle and horizontal deflection angle of each calibration position relative to the origin of the spherical coordinate system and the second coordinate of each receiving channel in the preset rectangular coordinate system, and determine the calibration coefficient corresponding to each received signal, wherein the spherical coordinate system and the rectangular coordinate system both take the first receiving channel preset in the FMCW radar as the origin.

[0135] In some embodiments, the device also includes an establishment module for establishing a rectangular coordinate system with the first receiving antenna corresponding to the first receiving channel as the origin, the horizontal direction of the first receiving antenna as the X-axis, the vertical direction of the first receiving antenna as the Z-axis, and the normal direction of the first receiving antenna as the Y-axis; and establishing a spherical coordinate system with the first receiving antenna corresponding to the first receiving channel as the origin, the length of the line between the first receiving antenna and the coordinate point as the distance r, the angle between the line and the horizontal plane XOY of the first receiving antenna as the vertical deflection angle μ, and the angle between the line and the vertical plane YOZ of the first receiving antenna as the horizontal deflection angle ν.

[0136] In some of the embodiments, the acquisition module 80 is further configured to select a first coordinate point on the Y-axis, wherein the distance between the first coordinate point and the origin matches the detection distance of the FMCW radar; based on the effective field of view angle of the FMCW radar, trigger the selection of a second coordinate point along the positive direction of the X-axis from the first coordinate point, wherein the line between the first coordinate point and the second coordinate point is perpendicular to the Y-axis, and place a reflector at the second coordinate point so that the reflector faces the FMCW radar; rotate the FMCW radar around the Y-axis in a first direction by multiple preset angles to obtain echo data at multiple preset calibration positions; or rotate the reflector around the Y-axis in a second direction by multiple preset angles to obtain echo data at multiple preset calibration positions, wherein the first direction is opposite to the second direction.

[0137] In some of the embodiments, the extraction module 81 is also configured to extract from the echo data a plurality of pulse signals collected by each receiving channel from each calibrated position; determine an average value of the plurality of pulse signals, and use the average value of the plurality of pulse signals as the receiving signal collected by each receiving channel from each calibrated position; and determine a phase value and an energy value of each receiving signal.

[0138] In some of the embodiments, the extraction module 81 is further configured to extract multiple pulse signals from the echo data; perform A / D sampling and fast Fourier transform based on the distance dimension on each pulse signal to obtain the distance interval corresponding to each pulse signal; determine the calibration position and receiving channel corresponding to each pulse signal based on the distance between each calibration position and the FMCW radar, as well as the distance interval and relative intensity corresponding to each pulse signal.

[0139] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0140] This embodiment also provides an electronic device, Fig. 9 is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present application, such as Fig. 9 As shown, the electronic device includes a memory 904 and a processor 902. The memory 904 stores a computer program, and the processor 902 is configured to run the computer program to execute the steps in any of the above method embodiments.

[0141] Specifically, the processor 902 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0142] The memory 904 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 904 may include a hard disk drive (HDD), a floppy disk drive, a solid state drive (SSD), a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 904 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 904 may be inside or outside the calibration coefficient determination device of the FMCW radar. In a specific embodiment, the memory 904 is a non-volatile memory. In a specific embodiment, the memory 904 includes a read-only memory (ROM) and a random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (Programmable Read-Only Memory, PROM for short), an erasable PROM (Erasable Programmable Read-Only Memory, EPROM for short), an electrically erasable PROM (Electrically Erasable Programmable Read-Only Memory, EEPROM for short), an electrically alterable ROM (Electrically Alterable Read-Only Memory, EAROM for short) or a flash memory (FLASH) or a combination of two or more of these. Under appropriate circumstances, the RAM can be a static random access memory (SRAM) or a dynamic random access memory (DRAM), wherein the DRAM can be a fast page mode dynamic random access memory (FPMDRAM), an extended data output dynamic random access memory (EDODRAM), a synchronous dynamic random access memory (SDRAM), etc.

[0143] The memory 904 may be used to store or cache various data files required for processing and / or communication, as well as possible computer program instructions executed by the processor 902 .

[0144] The processor 902 implements any one of the methods for determining the calibration coefficient of the FMCW radar in the above embodiments by reading and executing the computer program instructions stored in the memory 904 .

[0145] Optionally, the electronic device may further include a transmission device 906 and an input / output device 908 , wherein the transmission device 906 is connected to the processor 902 , and the input / output device 908 is connected to the processor 902 .

[0146] Optionally, in this embodiment, the processor 902 may be configured to perform the following steps through a computer program:

[0147] S1, obtaining echo data at multiple preset calibration positions.

[0148] S2, based on the echo data, extracting the phase value and energy value of the receiving signal collected by each receiving channel from each calibration position.

[0149] S3, performing phase compensation on the phase value of each received signal according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, and determining the calibration coefficient corresponding to each received signal.

[0150] S4, determining an optimization problem with the goal of maximizing the combined energy after coherent combination of the energies of all received signals collected from the first calibration position, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined at least based on the energy value of each received signal and the calibration coefficient corresponding to each received signal.

[0151] S5, determining the best calibration coefficient corresponding to each receiving channel based on the optimization problem.

[0152] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here.

[0153] In addition, in combination with the calibration coefficient determination method of the FMCW radar in the above embodiment, the embodiment of the present application can provide a storage medium for implementation. The storage medium stores a computer program; when the computer program is executed by the processor, any one of the calibration coefficient determination methods of the FMCW radar in the above embodiment is implemented.

[0154] Those skilled in the art should understand that the technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0155] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining a calibration coefficient of an FMCW radar, applied to phase calibration of an FMCW radar, wherein the FMCW radar comprises a plurality of receiving channels, and is characterized in that: The method comprises: Acquiring echo data at a plurality of preset calibration positions; Based on the echo data, extracting the phase value and energy value of the received signal collected by each receiving channel from each calibrated position; According to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal respectively, and a calibration coefficient corresponding to each received signal is determined; An optimization problem is determined with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position is coherently combined, including: obtaining the distance of each calibration position from the FMCW radar; performing energy calibration on the energy of each received signal according to the distance between the calibration position corresponding to the received signal and the FMCW radar, and determining the energy coefficient corresponding to each received signal; according to the energy coefficient and the calibration coefficient corresponding to each received signal, with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position is coherently combined, determining the optimization problem, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined based on at least the energy value of each received signal and the calibration coefficient corresponding to each received signal; Based on the optimization problem, an optimal calibration coefficient corresponding to each receiving channel is determined.

2. The method for determining the calibration coefficient of the FMCW radar according to claim 1, characterized in that: The optimization problem is expressed as: Where S is a set of optimal calibration coefficients corresponding to each receiving channel, S = (S1, S2, ..., S N ), the FMCW radar includes N receiving channels, M is the number of the calibration positions, P (i) is a set of energy coefficients corresponding to the calibration position i, X (i) is a set of calibration coefficients corresponding to the calibration position i, is the energy coefficient corresponding to the calibration position i and the receiving channel k, s k is the optimal energy coefficient corresponding to receiving channel k, is the calibration coefficient corresponding to the calibration position i and the receiving channel k, k∈{1,2,…,N}, i∈{1,2,…,M}.

3. The method for determining the calibration coefficient of the FMCW radar according to claim 1, characterized in that: According to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, phase compensation is performed on the phase value of each received signal respectively, and the calibration coefficient corresponding to each received signal is determined, including: Determine the vertical deflection angle and the horizontal deflection angle of each calibrated position relative to the origin of the spherical coordinate system according to the first coordinate of the calibrated position corresponding to the received signal in the preset spherical coordinate system; According to the vertical deflection angle and the horizontal deflection angle of each calibrated position relative to the origin of the spherical coordinate system and the second coordinate of each receiving channel in the preset rectangular coordinate system, phase compensation is performed on the phase value of each received signal, and a calibration coefficient corresponding to each received signal is determined, wherein the spherical coordinate system and the rectangular coordinate system both take the first receiving channel preset in the FMCW radar as the origin.

4. The method for determining the calibration coefficient of the FMCW radar according to claim 3, characterized in that: Before acquiring echo data at a plurality of preset calibration positions, the method further includes: Establishing the rectangular coordinate system with the first receiving antenna corresponding to the first receiving channel as the origin, the horizontal direction of the first receiving antenna as the X-axis, the vertical direction of the first receiving antenna as the Z-axis, and the normal direction of the first receiving antenna as the Y-axis; The spherical coordinate system is established by taking the first receiving antenna corresponding to the first receiving channel as the origin, the length of the line between the first receiving antenna and the coordinate point as the distance r, the angle between the line and the horizontal plane XOY of the first receiving antenna as the vertical deflection angle μ, and the angle between the line and the vertical plane YOZ of the first receiving antenna as the horizontal deflection angle v.

5. The method for determining the calibration coefficient of the FMCW radar according to claim 4, characterized in that: Acquiring echo data at multiple preset calibration positions includes: Selecting a first coordinate point on the Y-axis, wherein a distance between the first coordinate point and the origin matches a detection distance of the FMCW radar; According to the effective field of view of the FMCW radar, a second coordinate point is selected along the positive direction of the X-axis from the first coordinate point, wherein a line between the first coordinate point and the second coordinate point is perpendicular to the Y-axis, and a reflector is placed at the second coordinate point so that the reflector faces the FMCW radar; Rotate the FMCW radar around the Y axis by a plurality of preset angles in a first direction to obtain echo data at a plurality of preset calibration positions; Or the reflector is rotated around the Y-axis by a plurality of preset angles in a second direction to obtain echo data at a plurality of preset calibration positions, wherein the first direction is opposite to the second direction.

6. The method for determining the calibration coefficient of the FMCW radar according to claim 1, characterized in that: Based on the echo data, extracting the phase value and energy value of the received signal collected by each receiving channel from each calibration position includes: Extracting multiple pulse signals collected by each receiving channel from each calibrated position from the echo data; Determine an average value of the multiple pulse signals, and use the average value of the multiple pulse signals as a receiving signal collected by each receiving channel from each calibration position; The phase value and energy value of each received signal are determined.

7. The method for determining the calibration coefficient of the FMCW radar according to claim 6, characterized in that: Extracting a plurality of pulse signals collected by each receiving channel from each calibrated position from the echo data comprises: Extracting multiple pulse signals from the echo data; Each pulse signal is subjected to A / D sampling and fast Fourier transform based on the distance dimension to obtain the distance interval corresponding to each pulse signal; The calibration position and receiving channel corresponding to each pulse signal are determined according to the distance between each calibration position and the FMCW radar, and the distance interval and relative strength corresponding to each pulse signal.

8. A calibration coefficient determination device for an FMCW radar, applied to phase calibration of an FMCW radar, wherein the FMCW radar comprises a plurality of receiving channels, characterized in that: The device comprises: An acquisition module, used for acquiring echo data at a plurality of preset calibration positions; An extraction module, used to extract the phase value and energy value of the received signal collected by each receiving channel from each calibration position using the echo data; A compensation module, used to perform phase compensation on the phase value of each received signal according to the positional relationship between the calibration position corresponding to the received signal and the receiving channel corresponding to the received signal, and determine the calibration coefficient corresponding to each received signal; An optimization module, used to determine an optimization problem with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position is coherently combined, including: obtaining the distance of each calibration position from the FMCW radar; performing energy calibration on the energy of each received signal according to the distance between the calibration position corresponding to the received signal and the FMCW radar, and determining the energy coefficient corresponding to each received signal; determining the optimization problem with the goal of maximizing the combined energy after the energy of all received signals collected from the first calibration position is coherently combined according to the energy coefficient and calibration coefficient corresponding to each received signal, wherein the combined energy corresponding to the first calibration position is less than or equal to the combined energy corresponding to any calibration position, and the optimization problem is determined based on at least the energy value of each received signal and the calibration coefficient corresponding to each received signal; The output module is used to determine the best calibration coefficient corresponding to each receiving channel based on the optimization problem.

9. An electronic device comprising a memory and a processor, characterized in that: A computer program is stored in the memory, and the processor is configured to run the computer program to execute the calibration coefficient determination method for the FMCW radar according to any one of claims 1 to 7.

10. A storage medium, characterized in that: The storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the method for determining a calibration coefficient of an FMCW radar according to any one of claims 1 to 7.

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