A target trajectory measurement method based on phase bias estimation and electronic device

Abstract

The application discloses a target trajectory measurement method and electronic equipment based on phase bias estimation. The method comprises the following steps: obtaining the measurement results of the distance, phase, detection time and the like of a plurality of array elements to a target; modeling the observation geometric relationship; obtaining the relationship matrix of the phase and the target detection time and distance; and calculating the intersection of the target trajectory and the radar plane. The patent takes linear motion as the starting point, models the phase and target trajectory in the target motion process, eliminates the influence of the phase bias by using the relationship between the target trajectory parameters and the phase change rule, and effectively solves the problem of array antenna phase bias estimation. The patent uses the motion characteristics of the target to propose a phase bias estimation method based on the motion characteristics of the target to meet the high-precision measurement requirement of the phase of the array radar system target detection, can realize high-precision estimation of the motion trajectory, and completes the phase bias calibration of the antenna array.

Description

Technical Field

[0001] This application relates to the technical field of array radar target detection, and in particular to a target trajectory measurement method and electronic device based on phase offset estimation. Background Technology

[0002] This invention originates from a target detection radar system that employs multi-antenna, multi-channel interferometric angle measurement technology. Traditional algorithms require phase offsets between multiple antennas, which need to be measured through anechoic chamber calibration. Specific installation geometry makes it impossible to accurately measure the phase relationship in the final state of the equipment, while target detection demands high-precision phase measurement. Summary of the Invention

[0003] This application provides a target trajectory measurement method and electronic device based on phase offset estimation, aiming to achieve high-precision estimation of motion trajectory. This method effectively solves the problem of requiring anechoic chamber measurement for phase offset, avoiding the need for anechoic chamber testing. The effectiveness of this method has been effectively verified through simulation and testing.

[0004] In a first aspect, a target trajectory measurement method based on phase offset estimation is provided, characterized by comprising:

[0005] Obtain L measurement results of the target from J+1 array elements on the first coordinate axis. Each measurement result includes the detection time, detection distance, and J phase measurement values ​​corresponding to the J+1 array elements. The motion trajectory of the target relative to the first coordinate axis satisfies a first functional relationship, which includes N unknown coefficients related to the detection time.

[0006] Based on the L measurement results, the phase deviation values ​​of the target relative to the J+1 array elements and the N unknown coefficients are determined by the least squares method, thereby determining the trajectory of the target.

[0007] In conjunction with the first aspect, in certain implementations of the first aspect, determining the phase deviation values ​​of the target relative to the plurality of array elements and the N unknown coefficients includes:

[0008] Establish the solution relation Ax = b. Where, d j R is the distance between array element j+1 and array element 1. i The detection range of the target is [value]. Let be the phase deviation value of array element j, and s represent the unknown coefficient. Let be the phase measurement value of array element j, and i represent the i-th detection;

[0009] By solving Solve for x. This represents the pseudo-inverse of matrix A.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, J=2, the trajectory of the target relative to the first coordinate axis satisfies a linear motion relationship, and the N unknown coefficients include the coordinates y0 of the intersection point of the first functional relationship and the radar plane, and the slope k of the linear motion relationship. y ;

[0011] The solution relation satisfies A y x y =b y ,in

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the method further includes:

[0013] Obtain L measurement results of the target from M+1 array elements on the second coordinate axis, the second coordinate axis being perpendicular to the first coordinate axis. Each measurement result includes the detection time, detection distance, and M phase measurement values ​​corresponding to the M+1 array elements. The trajectory of the target relative to the second coordinate axis satisfies a second functional relationship, which includes P unknown coefficients related to the detection time.

[0014] Based on the L measurement results, the phase deviation values ​​of the target relative to the M+1 array elements and the P unknown coefficients are determined by the least squares method.

[0015] Determining the trajectory of the target includes:

[0016] The trajectory of the target is determined based on the first functional relationship and the second functional relationship.

[0017] In conjunction with the first aspect, in some implementations of the first aspect, the trajectory of the target relative to the third coordinate axis is determined by the detection distance of the target at different detection times, and the third coordinate axis is perpendicular to the first coordinate axis and the second coordinate axis.

[0018] In conjunction with the first aspect, in some implementations of the first aspect, 2≤J≤5.

[0019] In conjunction with the first aspect, in some implementations of the first aspect, 2≤N≤5.

[0020] In conjunction with the first aspect, in some implementations of the first aspect, L≥100.

[0021] In a second aspect, an electronic device is provided for performing the method as described in any of the implementations of the first aspect above.

[0022] Compared with the prior art, the solution provided in this application has at least the following beneficial technical effects:

[0023] This patent takes linear motion as its starting point, models the phase and trajectory of the target during its motion, and utilizes the relationship between target trajectory parameters and phase change patterns to eliminate the influence of phase offset, effectively solving the problem of phase offset estimation for array antennas. Addressing the high-precision phase measurement requirements of array radar systems for target detection, this patent proposes a phase offset estimation method based on target motion characteristics, enabling high-precision estimation of the motion trajectory while simultaneously calibrating the phase offset of the antenna array. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of radar observation geometry and target trajectory. Detailed Implementation

[0025] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] For radar systems employing multi-antenna, multi-channel interferometric angle measurement technology, precise measurement of the phase offset between multiple antennas is required, typically achieved through anechoic chamber calibration. In practice, because the trajectory of the target follows a straight line or parabola, the variables in its motion function are relatively few, while the measurement results include information such as detection time, distance, and phase at multiple target positions, making it an overdetermined problem in estimation theory. To address this issue, this patent proposes a phase offset estimation method based on target motion characteristics, enabling high-precision estimation of the motion trajectory. This method effectively solves the problem of requiring anechoic chamber measurements for phase offset, avoiding the need for anechoic chamber testing. The method's effectiveness has been verified through simulation and testing. This patent uses linear motion as an example to illustrate the method.

[0027] 1. Introduction to the Principle of Measuring Geometric Structures

[0028] Assume the center of the radar array is the origin, the array is in the ZY plane, and its normal is the -X axis. For example... Figure 1 The intersection of the target and the radar surface is (0, y). b ,z b ) T The target trajectory is a straight line, and the minimum detectable distance is R. min The maximum detectable distance is R. max The sampling time is Ti .

[0029] Depend on Figure 1 It can be seen that the phase change pattern of the target during the motion process is different for different quadrants. By using the phase change pattern, the quadrant where the intersection point is located can be basically determined, as shown in Table 1.

[0030] Table 1

[0031]

[0032] This patent models and analyzes the phase change pattern during target motion, discovering a correlation between the phase change pattern and the target's motion characteristics when the target is in different observation quadrants. This effectively avoids the influence of phase offset on target trajectory measurement. Here, λ is the radar operating wavelength. For the phase values ​​of antenna 1 measured by the array, d1, d2, d3, and d4 represent the distances between the antennas. θ z ,θ y The angle between the line connecting the target and the radar origin and the XOZ and XOY planes.

[0033] 2. Relationship between phase and target position

[0034] Assume the radar detects the target at time T. i The measured target distance is R i and the phase of the corresponding array element is The number of measurement points is L. (From...) Figure 1 It can be seen that, assuming the distances between array elements d1, d2, d3, and d4 are positive, then the phase values ​​between array elements are...

[0035]

[0036]

[0037] Where θ zi ,θ yi For the target time T i The angle between the line connecting the position and the radar origin and the XOZ and XOY planes. Since there may be phase deviation in the measured phase, this phase deviation is eliminated by phase difference, and the phase deviation value is estimated.

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] in This is the theoretical phase value. This is the phase deviation value. For a pair of phase measurements, the following relationship exists:

[0045]

[0046]

[0047]

[0048]

[0049] in To account for the phase offset after phase blurring, by Figure 1 It can be seen that when the target trajectory is determined, y i =y0+T i ·k y , z i =z0+T i ·k z Where k y Let k be the slope of the straight line projected onto the XOY plane by the target's trajectory. z Let be the slope of the straight line projected onto the XOZ plane by the target motion trajectory.

[0050] 3. Phase offset and intersection point estimation

[0051] According to the trajectory, the phase change and position are subject to the following constraints, y i =y0+T i ·k y ,

[0052]

[0053]

[0054] Where k y The slope of the target motion in the XOY plane is obtained after transformation and simplification.

[0055]

[0056]

[0057] After transformation and simplification, we get

[0058]

[0059]

[0060] in By solving the above system of linear equations, the phase bias of the system can be calculated, and the least squares method can be considered. The above can be simplified to obtain...

[0061]

[0062]

[0063]

[0064]

[0065] Therefore, solving for the phase offset and the intersection point of the target and the radar plane involves solving the following linear equation.

[0066] A y x y =b y

[0067] in

[0068]

[0069]

[0070] It can be obtained in Representing matrix A y The false rebellion.

[0071] According to the trajectory, the phase change and position are subject to the following constraint, z i =z0+T i ·k z ,

[0072]

[0073]

[0074] Where k y The slope of the target motion in the XOY plane is obtained after transformation and simplification.

[0075]

[0076]

[0077] After transformation and simplification, we get

[0078]

[0079]

[0080] in By solving the above system of linear equations, the phase bias of the system can be calculated, and the least squares method can be considered. The above can be simplified to obtain...

[0081]

[0082]

[0083]

[0084]

[0085] Therefore, solving for the phase offset and the intersection point of the target and the radar plane involves solving the following linear equation.

[0086] A z x z =b z

[0087] in

[0088]

[0089]

[0090] It can be obtained in Representing matrix A z The false rebellion.

[0091] In the above embodiment, the target moves along a straight line, therefore this linear motion satisfies a linear function relationship along a certain axis. This function relationship has two unknown coefficients: the starting position and the slope of the line. In other embodiments, the target may not move along a straight line, and its trajectory may satisfy other functional relationships. The unknown coefficients of this functional relationship can be calculated using L measurement results. The number of unknown coefficients should not be too large to avoid affecting the solution speed.

[0092] The calculation method provided by this invention can make the initial position unaffected by phase deviation and simultaneously complete the calculation of motion parameters.

[0093] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A target trajectory measurement method based on phase offset estimation, characterized in that, include: Obtain L measurement results of the target from J+1 array elements on the first coordinate axis. Each measurement result includes the detection time, detection distance, and J phase measurement values ​​corresponding to the J+1 array elements. The motion trajectory of the target relative to the first coordinate axis satisfies a first functional relationship, which includes N unknown coefficients related to the detection time. Based on the L measurement results, the phase deviation values ​​of the target relative to the J+1 array elements and the N unknown coefficients are determined by the least squares method, thereby determining the target's trajectory. J=2, the target's trajectory relative to the first coordinate axis satisfies a linear motion relationship, and the N unknown coefficients include the coordinates of the intersection point of the first functional relationship and the radar plane. and the slope of the linear motion relationship. ; Solving for the relationship satisfies ,in , , , , , , , , ; i represents the i-th probe, For the target time; The operating wavelength of the radar; , Let j+1 be the distance between array element j and array element j. R is the phase deviation value of array element j. i The detection range of the target is [value]. The phase measurement value of array element j.

2. The method according to claim 1, characterized in that, The method further includes: Obtain L measurement results of the target from M+1 array elements on the second coordinate axis, the second coordinate axis being perpendicular to the first coordinate axis. Each measurement result includes the detection time, detection distance, and M phase measurement values ​​corresponding to the M+1 array elements. The trajectory of the target relative to the second coordinate axis satisfies a second functional relationship, the second functional relationship including P unknown coefficients related to the detection time. Based on the L measurement results, the phase deviation values ​​of the target relative to the M+1 array elements and the P unknown coefficients are determined by the least squares method. Determining the trajectory of the target includes: The trajectory of the target is determined based on the first functional relationship and the second functional relationship.

3. The method according to claim 2, characterized in that, The trajectory of the target relative to the third coordinate axis is determined by the detection distance of the target at different detection times, and the third coordinate axis is perpendicular to the first coordinate axis and the second coordinate axis.

4. The method according to claim 1, characterized in that, L≥100。 5. An electronic device, characterized in that, The electronic device is used to perform the method as described in any one of claims 1 to 4.

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