Millimeter wave radar velocity deambiguation method and system

Abstract

The present invention belongs to the technical field of millimeter wave radar, and relates to a millimeter wave radar speed deambiguation method and system. The method comprises: a transmitter transmits a first group of transmission waveform signals and a second group of transmission waveform signals; performs two-dimensional FFT processing on the echo signal to obtain two-dimensional spectrum data; performs target detection on the two-dimensional spectrum data to obtain detection results; performs target angle measurement on each target obtained by target detection to obtain angle information of each target; performs deambiguation matching using the remainder theorem until the match is successful, and obtains the speed ambiguity multiple when the match is successful; and calculates the true speed of the target. The present invention uses the target angle for hypothetical matching. Since the target angle is much more stable than the target amplitude and is not affected by RCS flicker, the success rate of target matching is greatly improved. At the same time, in the case of multiple targets, since the angles of each target are generally different, the success rate of deambiguation of multiple targets can also be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of millimeter wave radars, and in particular, relates to a millimeter wave radar velocity deambiguation method and system. Background Art

[0002] In millimeter-wave radar applications, the radar's unambiguous speed measurement range is determined by the radar's pulse repetition frequency. When the target speed exceeds the radar's unambiguous speed measurement range, the radar's speed measurement result for the target is ambiguous, so speed deambiguation is required.

[0003] Existing deambiguation methods usually use the staggered PRF (pulse repetition frequency) method for velocity deambiguation. By transmitting two sets of waveforms with different pulse repetition frequencies (PRFs), and performing target detection respectively, the two sets of targets are matched. It is usually considered that the detection points with similar target amplitudes are the same target, and the velocity ambiguity multiple is calculated using the Chinese remainder theorem. In the case of multiple targets, there are usually cases where the amplitudes of different targets are similar, which can easily lead to target matching errors and cause deambiguation failure; due to the flickering characteristics of the target's RCS (Radar Cross Section), the amplitudes of the two detection points of the same target obtained by the two sets of waveforms are very different, resulting in the inability to match the target, causing deambiguation failure. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a millimeter wave radar velocity deambiguation method and system.

[0005] In a first aspect, the present invention provides a millimeter wave radar velocity deambiguation method, comprising:

[0006] The transmitter transmits a first group of transmission waveform signals and a second group of transmission waveform signals; the first group of transmission waveform signals and the second group of transmission waveform signals are two groups of waveform signals with different pulse repetition periods;

[0007] The receiver receives the echo signals of the two sets of transmitted waveform signals, performs two-dimensional FFT processing on the echo signals, and obtains two-dimensional spectrum data;

[0008] Using the target detection CFAR algorithm to perform target detection on the two-dimensional spectrum data, and obtaining the detection results corresponding to the first group of transmitted waveform signals and the detection results corresponding to the second group of transmitted waveform signals;

[0009] Measure the angle of each target detected to obtain the angle information of each target;

[0010] Based on the angle information of the target, the remainder theorem is used to perform defuzzification matching, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of emission waveform signals; using the maximum unambiguous speed of the second group of emission waveform signals to find the remainder of the real speed, and obtaining the detection speed of the target in the second group of emission waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of emission waveform signals until a match is successful, and obtaining the speed fuzzy multiple when the match is successful;

[0011] The real speed of the target is calculated based on the detection speed and the speed fuzzy multiple when the match is successful.

[0012] In a second aspect, the present invention provides a millimeter wave radar velocity deambiguation system, including a transmitting unit, a receiving unit, a target detection unit, an angle measurement unit, a matching unit and a processing unit;

[0013] The transmitting unit is used for transmitting a first group of transmitting waveform signals and a second group of transmitting waveform signals by a transmitter; the first group of transmitting waveform signals and the second group of transmitting waveform signals are two groups of waveform signals with different pulse repetition periods;

[0014] A receiving unit, used for receiving the echo signals of the two sets of transmission waveform signals by a receiver, performing two-dimensional FFT processing on the echo signals to obtain two-dimensional spectrum data;

[0015] A target detection unit, used to perform target detection on the two-dimensional spectrum data using a target detection CFAR algorithm, and obtain a detection result corresponding to the first group of transmitted waveform signals and a detection result corresponding to the second group of transmitted waveform signals;

[0016] An angle measurement unit, used to measure the angle of each target detected to obtain angle information of each target;

[0017] The matching unit is used to perform defuzzification matching based on the angle information of the target using the remainder theorem, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of transmitted waveform signals; using the maximum unambiguous speed of the second group of transmitted waveform signals to find the remainder of the real speed to obtain the detection speed of the target in the second group of transmitted waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of transmitted waveform signals until the match is successful, and obtaining the speed fuzzy multiple when the match is successful;

[0018] The processing unit is used to calculate the real speed of the target according to the detection speed and the speed fuzzy multiple when the match is successful.

[0019] Based on the above technical solution, the present invention can also be improved as follows.

[0020] Further, suppose is the target distance dimension position, is the Doppler position of the target, and the position of the target obtained by target detection is expressed in coordinates Said that The position of the target is represented by , set the The angle of the target is , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the first set of emission waveform signals is represented as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , is the maximum fuzzy number, and the speed fuzzy multiple is set to , is an integer, and the maximum unambiguous speed of the first set of transmitted waveform signals is , the maximum unambiguous speed of the second set of transmitted waveform signals is , set the speed fuzzy multiple to correspond to the actual speed ,but: .

[0021] Furthermore, let the detection speed of the target in the second set of transmitted waveform signals be , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , search for a target that matches the detection speed in the detection results corresponding to the second set of transmitted waveform signals, if there is one , so that ,and If it is less than or equal to the set threshold, the match is successful, otherwise the speed fuzzy multiple is reset until the match is successful, and the speed fuzzy multiple when the match is successful is obtained.

[0022] Furthermore, let the speed fuzzy multiple when the match is successful be , the maximum unambiguous speed of the first set of transmitted waveform signals is , the target's true speed is ,but:

[0023] .

[0024] The beneficial effects of the present invention are as follows: the present invention uses the target angle for hypothesis matching. Since the target angle is much more stable than the target amplitude and is not affected by RCS flicker, the success rate of target matching is greatly improved. At the same time, in the case of multiple targets, since the angles of each target are generally different, the success rate of deambiguation of multiple targets can also be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a millimeter wave radar velocity deambiguation method provided in Example 1 of the present invention;

[0026] Figure 2 A waveform diagram of a transmitter transmitting two types of transmission waveform signals with different pulse repetition periods;

[0027] Figure 3 It is a schematic diagram of the speed and position of the target in the detection results corresponding to the two sets of emission waveform signals;

[0028] Figure 4 This is a schematic diagram of a millimeter wave radar velocity deambiguation system provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Example 1

[0031] As an example, Figure 1 As shown, in order to solve the above technical problems, this embodiment provides a millimeter wave radar speed deambiguation method, including:

[0032] The transmitter transmits a first group of transmission waveform signals and a second group of transmission waveform signals; the first group of transmission waveform signals and the second group of transmission waveform signals are two groups of waveform signals with different pulse repetition periods;

[0033] The receiver receives the echo signals of the two sets of transmitted waveform signals, performs two-dimensional FFT processing on the echo signals, and obtains two-dimensional spectrum data;

[0034] Using the target detection CFAR algorithm to perform target detection on the two-dimensional spectrum data, and obtaining the detection results corresponding to the first group of transmitted waveform signals and the detection results corresponding to the second group of transmitted waveform signals;

[0035] Measure the angle of each target detected to obtain the angle information of each target;

[0036] Based on the angle information of the target, the remainder theorem is used to perform defuzzification matching, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of emission waveform signals; using the maximum unambiguous speed of the second group of emission waveform signals to find the remainder of the real speed, and obtaining the detection speed of the target in the second group of emission waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of emission waveform signals until a match is successful, and obtaining the speed fuzzy multiple when the match is successful;

[0037] The real speed of the target is calculated based on the detection speed and the speed fuzzy multiple when the match is successful.

[0038] In actual application, the transmitter transmits two kinds of transmission waveform signals with different pulse repetition periods, as shown in the attached figure. Figure 2 As shown, Figure 2 (a) in the figure is the first set of transmitted waveform signals. Figure 2 (b) is the second set of transmitted waveform signals, the horizontal axis is time t, the vertical axis is frequency f, the low level duration of the first set of transmitted waveform signals is Tw1, the high level duration is Tc1, the low level duration of the second set of transmitted waveform signals is Tw2, the high level duration is Tc2, as shown in the attached figure. Figure 2 As shown, Tw1 is smaller than Tw2.

[0039] The receiver receives two sets of echo signals and performs two-dimensional FFT processing to obtain two sets of two-dimensional FFT spectra. For the same target, due to the different pulse repetition frequencies of the transmitted signal, the speed and position of the same target on the two sets of spectra are different, as shown in the following figure. Figure 3 The solid points shown represent the targets. Figure 3 (c) in the figure is the target in the detection result corresponding to the first set of emission waveform signals. Figure 3 (d) in FIG. 1 is a target in the detection result corresponding to the second set of emission waveform signals, where the horizontal axis represents the speed V and the vertical axis represents the position R.

[0040] Optional, set is the target distance dimension position, is the Doppler position of the target, and the position of the target obtained by target detection is expressed in coordinates Said that The position of the target is represented by , set the The angle of the target is , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the first set of emission waveform signals is represented as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , is the maximum fuzzy number, and the speed fuzzy multiple is set to , is an integer, and the maximum unambiguous speed of the first set of transmitted waveform signals is , the maximum unambiguous speed of the second set of transmitted waveform signals is , set the speed fuzzy multiple to correspond to the actual speed ,but: .

[0041] The set of detection results corresponding to the first set of transmitted waveform signals is , the set of detection results corresponding to the first set of transmitted waveform signals is , the detection result set of the first set of transmitted waveform signals Each goal in , set the speed blur multiple to , calculate the assumed true speed , then the maximum unambiguous speed of the second set of transmitted waveform signals The actual speed corresponding to the set speed blur multiple Find the remainder and get the detection speed of the target in the second set of transmitted waveform signals , based on which the set of detection results of the second set of transmitted waveforms Find whether there is a speed Detection detection target.

[0042] Optionally, the detection speed of the target in the second set of transmitted waveform signals is assumed to be , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , search for a target that matches the detection speed in the detection results corresponding to the second set of transmitted waveform signals, if there is one , so that ,and If it is less than or equal to the set threshold, the match is successful, otherwise the speed fuzzy multiple is reset until the match is successful, and the speed fuzzy multiple when the match is successful is obtained.

[0043] ,and Less than or equal to the set threshold, indicating that the frequency spectrum points corresponding to the second group of transmitted waveform signals have the same speed and the same or similar angles as the frequency spectrum points corresponding to the second group of transmitted waveform signals. Under this condition, the target in the detection result corresponding to the second group of transmitted waveform signals is successfully matched. If the match is not successful, the next assumption multiple is continued for matching verification until the target is successfully matched.

[0044] Optionally, set the speed fuzzy multiplier when the match is successful to , the maximum unambiguous speed of the first set of transmitted waveform signals is , the target's true speed is ,but:

[0045] .

[0046] Before performing speed defuzzification operation on the target, the present invention first measures the angle of the target to obtain the angle measurement result of each target. In the speed defuzzification process, the target angle is used for defuzzification matching, instead of the traditional matching using the target amplitude. The traditional defuzzification method uses the target amplitude for matching. Since the target amplitude is affected by the target RCS flicker and changes greatly, the difference in the same target amplitude obtained by the two sets of emission waveforms may be very large, which easily leads to defuzzification failure. The present invention innovatively uses the target angle for hypothesis matching. Since the target angle is much more stable than the target amplitude and is not affected by the RCS flicker, the success rate of target matching is greatly improved. At the same time, in the case of multiple targets, since the angles of each target are generally different, the success rate of defuzzification of multiple targets can also be improved.

[0047] Example 2

[0048] Based on the same principle as the method shown in Example 1 of the present invention, as shown in the attached Figure 4 As shown, an embodiment of the present invention further provides a millimeter wave radar speed deambiguation system, including a transmitting unit, a receiving unit, a target detection unit, an angle measurement unit, a matching unit and a processing unit;

[0049] The transmitting unit is used for transmitting a first group of transmitting waveform signals and a second group of transmitting waveform signals by a transmitter; the first group of transmitting waveform signals and the second group of transmitting waveform signals are two groups of waveform signals with different pulse repetition periods;

[0050] A receiving unit, used for receiving the echo signals of the two sets of transmission waveform signals by a receiver, performing two-dimensional FFT processing on the echo signals to obtain two-dimensional spectrum data;

[0051] A target detection unit, used to perform target detection on the two-dimensional spectrum data using a target detection CFAR algorithm, and obtain a detection result corresponding to the first group of transmitted waveform signals and a detection result corresponding to the second group of transmitted waveform signals;

[0052] An angle measurement unit, used to measure the angle of each target detected to obtain angle information of each target;

[0053] The matching unit is used to perform defuzzification matching based on the angle information of the target using the remainder theorem, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of transmitted waveform signals; using the maximum unambiguous speed of the second group of transmitted waveform signals to find the remainder of the real speed to obtain the detection speed of the target in the second group of transmitted waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of transmitted waveform signals until the match is successful, and obtaining the speed fuzzy multiple when the match is successful;

[0054] The processing unit is used to calculate the real speed of the target according to the detection speed and the speed fuzzy multiple when the match is successful.

[0055] Optional, set is the target distance dimension position, is the Doppler position of the target, and the position of the target obtained by target detection is expressed in coordinates Said that The position of the target is represented by , set the The angle of the target is , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the first set of emission waveform signals is represented as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , is the maximum fuzzy number, and the speed fuzzy multiple is set to , is an integer, and the maximum unambiguous speed of the first set of transmitted waveform signals is , the maximum unambiguous speed of the second set of transmitted waveform signals is , set the speed fuzzy multiple to correspond to the actual speed ,but: .

[0056] Optionally, the detection speed of the target in the second set of transmitted waveform signals is assumed to be , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , search for a target that matches the detection speed in the detection results corresponding to the second set of transmitted waveform signals, if there is one , so that ,and If it is less than or equal to the set threshold, the match is successful, otherwise the speed fuzzy multiple is reset until the match is successful, and the speed fuzzy multiple when the match is successful is obtained.

[0057] Optionally, set the speed fuzzy multiplier when the match is successful to , the maximum unambiguous speed of the first set of transmitted waveform signals is , the target's true speed is ,but:

[0058] .

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A millimeter wave radar velocity deambiguation method, characterized in that: include: The transmitter transmits a first group of transmission waveform signals and a second group of transmission waveform signals; The first group of transmitting waveform signals and the second group of transmitting waveform signals are two groups of waveform signals with different pulse repetition periods; The receiver receives the echo signals of the two sets of transmitted waveform signals, performs two-dimensional FFT processing on the echo signals, and obtains two-dimensional spectrum data; Using the target detection CFAR algorithm to perform target detection on the two-dimensional spectrum data, and obtaining the detection results corresponding to the first group of transmitted waveform signals and the detection results corresponding to the second group of transmitted waveform signals; Measure the angle of each target detected to obtain the angle information of each target; Based on the angle information of the target, the remainder theorem is used to perform defuzzification matching, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of emission waveform signals; using the maximum unambiguous speed of the second group of emission waveform signals to find the remainder of the real speed, and obtaining the detection speed of the target in the second group of emission waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of emission waveform signals until a match is successful, and obtaining the speed fuzzy multiple when the match is successful; The real speed of the target is calculated based on the detection speed and the speed fuzzy multiple when the match is successful.

2. The millimeter wave radar velocity deambiguation method according to claim 1, characterized in that: set up is the target distance dimension position, is the Doppler position of the target, and the position of the target obtained by target detection is expressed in coordinates Said that The position of the target is represented by , set the The angle of the target is , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the speed of the target in the detection result corresponding to the first set of emission waveform signals is expressed as , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the first set of emission waveform signals is represented as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , is the maximum fuzzy number, and the speed fuzzy multiple is set to , is an integer, and the maximum unambiguous speed of the first set of transmitted waveform signals is , the maximum unambiguous speed of the second set of transmitted waveform signals is , set the speed fuzzy multiple to correspond to the actual speed ,but: .

3. The millimeter wave radar velocity deambiguation method according to claim 1, characterized in that: Assume that the detection speed of the target in the second set of transmitted waveform signals is , the angle of the target in the detection result corresponding to the first set of transmitted waveform signals is expressed as , the angle of the target in the detection result corresponding to the second set of transmitted waveform signals is expressed as , the target in the detection result corresponding to the second set of emission waveform signals is represented as , search for a target that matches the detection speed in the detection results corresponding to the second set of transmitted waveform signals, if there is one , so that ,and If it is less than or equal to the set threshold, the match is successful, otherwise the speed fuzzy multiple is reset until the match is successful, and the speed fuzzy multiple when the match is successful is obtained.

4. The millimeter wave radar velocity deambiguation method according to claim 1, characterized in that: Suppose the speed fuzzy multiple when the match is successful is , the maximum unambiguous speed of the first set of transmitted waveform signals is , the target's true speed is ,but: 。 5. A millimeter wave radar velocity deambiguation system, characterized in that: It includes a transmitting unit, a receiving unit, a target detection unit, an angle measurement unit, a matching unit and a processing unit; A transmitting unit, used for transmitting a first group of transmitting waveform signals and a second group of transmitting waveform signals; The first group of transmitting waveform signals and the second group of transmitting waveform signals are two groups of waveform signals with different pulse repetition periods; A receiving unit, used for receiving the echo signals of the two sets of transmission waveform signals by a receiver, performing two-dimensional FFT processing on the echo signals to obtain two-dimensional spectrum data; A target detection unit, used to perform target detection on the two-dimensional spectrum data using a target detection CFAR algorithm, and obtain a detection result corresponding to the first group of transmitted waveform signals and a detection result corresponding to the second group of transmitted waveform signals; An angle measurement unit, used to measure the angle of each target detected to obtain angle information of each target; The matching unit is used to perform defuzzification matching based on the angle information of the target using the remainder theorem, including: calculating the real speed corresponding to the set speed fuzzy multiple according to each target in the detection results corresponding to the first group of transmitted waveform signals; using the maximum unambiguous speed of the second group of transmitted waveform signals to find the remainder of the real speed to obtain the detection speed of the target in the second group of transmitted waveform signals; searching for a target matching the detection speed in the detection results corresponding to the second group of transmitted waveform signals until the match is successful, and obtaining the speed fuzzy multiple when the match is successful; The processing unit is used to calculate the real speed of the target according to the detection speed and the speed fuzzy multiple when the match is successful.

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