Millimeter wave radar target detection method

Abstract

The invention relates to the field of radar target detection, in particular to a millimeter-wave radar target detection method, and solves the problem of low detection precision of miniaturized and low-power millimeter-wave radar waves in the prior art. The method comprises the following steps: S1, calibrating a to-be-tested environment; s2, the radar works in a first working mode in a low-frame-rate state, and whether the radar is the same target or not is determined; whether mode switching is carried out or not is determined; s3, switching the working mode of the radar to a second working mode of a high frame frequency state, and if the target can be detected within T3 time, entering step S4; and S4, the radar acts after detecting the target in the second working mode. According to the invention, the average power consumption of radar detection is greatly reduced by using multi-mode switching; the environment to be detected is partitioned, interference in the environment is recognized, the anti-interference performance is improved under the condition of low power consumption, and the detection precision and stability are improved.

Description

Technical Field

[0001] The present invention relates to the field of radar target detection, and in particular to a millimeter wave radar target detection method. Background Art

[0002] In recent years, with the development of the consumer millimeter wave market in smart home, security, industrial fields, etc., based on the considerations of cost reduction, easy installation, and generalized application, more markets require millimeter wave radars to have the conditions of miniaturization, high performance, and long battery life. For this reason, in recent years, miniaturized low-power radars have become the development trend of millimeter wave radars. However, miniaturization and low-power design make radars Detection accuracy decreases , susceptible to interference.

[0003] There is an urgent need for a new millimeter radar wave target detection method that can solve the above problems. Summary of the invention

[0004] The invention provides a millimeter wave radar target detection method, which solves the problem of low detection accuracy of miniaturized and low-power millimeter wave radars in the prior art.

[0005] The technical solution of the present invention is implemented as follows: a millimeter wave radar target detection method, comprising the following steps: S1: calibration of the environment to be tested: the radar is in a calibration mode, used to obtain the signal of the environment to be tested, and send it to the main control unit for analysis, and obtain and store the distance, speed, angle information and signal-to-noise ratio; the calibration hold time is T1; S2: the radar works in the first working mode of the low frame rate state: target detection is performed in each frame, and the signal is analyzed for the distance-speed spectrum, and the existence of the target is determined according to the set threshold value. If the signal exceeds the threshold, the distance, speed, and angle information of the target are obtained and the target is associated; when the distance, speed, and angle information of the target detected in the two frames meet the threshold, it is confirmed that they are the same target; from the Nth frame to the Nth frame, the target is detected. If the probability of detecting the same target exceeds P percent in the N+Wth frame, the radar enters step S3, otherwise it remains in S2; S3: the radar working mode is switched to the second working mode with a high frame rate: the holding time of the second working mode is T3; the radar detects the signal in each frame, detects the distance, speed and angle information of the target, if the radar fails to detect the target within T3, it exits the second working mode and returns to S2; if the target can be detected within T3, it enters step S4; S4: the action of the radar after detecting the target in the second working mode can be set independently; after the step S4 is completed, the millimeter wave radar can be set to enter the sleep state, and the sleep time window T4 is set. After T4, it returns to step S2 to restart the detection.

[0006] The calibration mode can partition the area to be tested, and store the distance, speed, and angle information of different areas separately for comparison with subsequent tests.

[0007] Interference information elimination: Targets continuously detected in S1 are stored as interference signals. When the radar works in the second working mode S3, the stored interference signals are eliminated first.

[0008] The step S2 also includes setting the frame period: setting the frame period to M levels, and the frame period of each level gradually increases; when the radar is started or returns to S2 from S3 or S4: the frame period starts from the first level, and if the mode switching condition is not met within the set time period, the frame period is increased step by step according to the time window T2, and the frame rate is reduced.

[0009] The actions after the target is detected in step S4 may include: (1) tracking the target, and after detecting the target, continuing detection in the next T3 time window until the target is not detected in the time window T3, and then returning to S2; (2) feeding back to the main control unit: sending a signal that the target is detected to the main control unit, returning to the detection state or issuing instructions to the controlled device, and the main control or controlled device carries out subsequent actions.

[0010] The present invention discloses a millimeter-wave radar target detection method, which uses multi-mode switching to greatly reduce the average power consumption of radar detection; by partitioning the environment to be tested and identifying interference in the environment, the anti-interference performance is improved under low power consumption conditions, and the detection accuracy and stability are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0012] Figure 1 : Radar normal working flow chart;

[0013] Figure 2 : Calibration mode flow chart. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] A millimeter wave radar target detection method disclosed in the present invention comprises the following steps:

[0016] S1: Calibration of the test environment: The radar is in calibration mode, which is used to obtain the signal of the test environment and send it to the main control unit for analysis, obtain and store the distance, speed, angle information and signal-to-noise ratio; the calibration hold time is T1; if T1 is set to 1 minute, it means that each calibration will last for 1 minute; at this time, the current environment is required to be the environment that the user needs to detect by the radar, and it is ensured that there are no pedestrians or vehicles waiting to be detected in the current environment;

[0017] S2: The radar works in the first working mode, and performs a low frame rate state for rough detection: no precise identification is required, so the millimeter wave radar is set to work in a low frame rate state to reduce the total power consumption. During the detection process, it is necessary to compare with the stored calibration information to eliminate the interference of complex environments and improve the reliability of detection. Target detection is performed in each frame, and the signal is analyzed for distance-speed spectrum. The presence of a target is determined according to the set threshold. If the signal exceeds the threshold, the distance, speed, and angle information of the target are obtained and the target is associated; when the distance, speed, and angle information of the target detected in the two frames meet the threshold, it is confirmed that they are the same target; the distance and speed information of the target can be obtained according to the position of the target in the distance-speed spectrum; the DOA direction of arrival positioning estimation is performed on the signal to obtain the angle information of the target; target association is performed between different frames, and when the distance, speed, and angle information of the target detected in the two frames meet the threshold, it is considered to be the same target; if there is a probability of more than P percent detecting the same target in the Nth frame to the N+Wth frame, the radar enters step S3, otherwise it remains in S2, where the detection time window W and the detection probability P can be set by the user according to actual needs;

[0018] S3: The radar working mode is switched to the second working mode, and a high frame rate state for accurate detection is performed: the second working mode is maintained for T3; the second working mode accurately detects and identifies the target in the first working mode; similarly, the signal detected by the radar in each frame needs to first eliminate the environmental interference in the calibration, and then detect the distance, speed, and angle information of the target. If the radar fails to detect the target within T3, the second working mode is exited and returned to S2; if the target can be detected within T3, step S4 is entered;

[0019] S4: The action of the radar after detecting the target in the second working mode can be set independently; after the step S4 is completed, the millimeter wave radar can be set to enter the sleep state, and the sleep time window T4 is set. After T4, it returns to step S2 to restart the detection. The user can set the sleep time window according to actual needs to avoid frequent entry into the second working mode due to the movement of the target in the detection area, and the poor user experience caused by frequent sending of signals to the master and controlled devices, while also reducing power consumption.

[0020] The calibration mode can partition the area to be tested: and store the distance, speed, and angle information of different areas separately for comparison with subsequent tests. By storing the signal characteristics of different areas for comparison with subsequent tests, the detection accuracy is improved. For example, if a target can be continuously detected in area A of the calibration mode, the target may be caused by interference in the environment, and the influence of the interference can be excluded when processing area A later.

[0021] Interference information elimination: Targets continuously detected in S1 are stored as interference signals. When the radar works in the second working mode S3, the stored interference signals are eliminated first.

[0022] If the environment to be detected remains unchanged, the calibration mode can be run only once at the initial startup. If the environment changes, recalibration is required. For example, if the radar is installed on the eaves and needs to detect whether there are people or cars entering the courtyard, it only needs to be calibrated once if the courtyard environment remains unchanged. However, if new landscape trees are planted in the courtyard, recalibration is required to avoid the impact of environmental changes on detection accuracy.

[0023] The step S2 also includes setting the frame period: setting the frame period to M levels, and the frame period of each level gradually increases; when the radar is started or returns to S2 from S3 or S4: the frame period starts from the first level, and if the mode switching condition is not met within the set time period, the frame period is gradually increased according to the time window T2, and the frame rate is reduced; for example, if the mode switching condition is not met within T2 time, the frame period rises to the second level, and if the mode switching condition is not met within the subsequent T2 time, the frame period rises to the third level, and so on, after the frame period reaches the Mth level, the level is maintained and no longer increased.

[0024] The actions after the target is detected in step S4 may include: (1) tracking the target, and after detecting the target, continuing detection in the next T3 time window until the target is not detected in the time window T3, and then returning to S2; (2) feedback to the main control unit: sending a signal that the target is detected to the main control unit, returning to the detection state or issuing instructions to the controlled device, and the main control or controlled device carries out subsequent actions, such as sending a detection signal to a mobile phone or controlling a camera to start recording, etc.

[0025] Combination Figure 1 Radar normal working flow chart and Figure 2As can be seen from the calibration mode flow chart, when the radar device starts working, it first enters the verification mode to calibrate the environment to be tested, partitions the environment to be tested, and extracts and stores the distance, speed, angle information and signal-to-noise ratio of each area respectively, and excludes the targets continuously detected in the environment, and stores the information in the main control unit. The device enters the first working mode, identifies the environment at a low frame rate, and compares each frame with the stored calibration information to eliminate the interference of complex environments and improve the reliability of detection; performs distance-speed spectrum analysis on the signal, and determines whether there is a target according to the set threshold. If the signal exceeds the threshold, it is considered that there is a target, and the distance and speed information of the target can be obtained according to the position of the target in the distance-speed spectrum. The DOA (direction of arrival) estimation of the signal can obtain the angle information of the target. Target association is performed between different frames, and when the distance, speed, and angle information of the target detected in two frames meet the threshold, it is considered to be the same target.

[0026] When the probability of detecting the same target exceeds P percent from the Nth frame to the N+Wth frame, the radar switches to the second working mode for more accurate high frame rate detection. Similarly, each frame is compared with the stored calibration information to eliminate the interference of complex environments and then detect the distance, speed and angle information of the target. If the radar can detect the target within T3 time, it goes to step S4. The subsequent actions are specified by the user.

[0027] After the subsequent actions are completed, the system may enter the sleep period and the first working mode according to user settings.

[0028] Through mode conversion, the radar can reduce power consumption while ensuring detection accuracy.

[0029] When no target is detected in the first working mode, the power consumption is further reduced by gradually reducing the frame period, thereby reducing the average power consumption of the radar.

[0030] Solve the problem of reduced detection accuracy of low-power radar: set a two-level working mode, and enter the second-level working mode for precise detection when the target is roughly detected, which can improve the detection accuracy and detection stability under the premise of low power consumption;

[0031] Solve the problem that low-power radar is easily affected by interference: Use the calibration mode to calibrate the environment to be tested before using the radar, eliminate interference such as metal, buildings, and plant shaking that may exist in complex environments, avoid the impact of interference detection, and improve detection accuracy;

[0032] Provides a detection solution with lower power consumption: The calibration mode extracts features and divides the area of ​​the test environment to avoid false detection due to interference during the detection process, effectively reducing power consumption; using a two-level working mode, when there is no target, the radar works in the first working mode, and the first working mode sets a multi-level frame period, which can reduce power consumption for scenes without targets for a long time; further, it can effectively reduce the average power consumption of the entire device.

[0033] The present invention discloses a millimeter-wave radar target detection method, which uses multi-mode switching to greatly reduce the average power consumption of radar detection; by partitioning the environment to be tested and identifying interference in the environment, the anti-interference performance is improved under low power consumption conditions, and the detection accuracy and stability are improved.

[0034] Of course, without departing from the spirit and essence of the invention, technicians familiar with the field should be able to make various corresponding changes and modifications based on the invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the invention.

Claims

1. A millimeter wave radar target detection method, characterized in that: The following steps are involved: S1: Calibration of the test environment: The radar is in calibration mode, which is used to obtain the signal of the test environment and send it to the main control unit for analysis, obtain and store the distance, speed, angle information and signal-to-noise ratio; the calibration hold time is T1; S2: The radar works in the first working mode with a low frame rate: target detection is performed in each frame, and the signal is analyzed for distance-velocity spectrum. The presence of a target is determined based on the set threshold. If the signal exceeds the threshold, the distance, speed, and angle information of the target are obtained and target association is performed. When the distance, speed, and angle information of the target detected in two frames meet the threshold, it is confirmed that they are the same target; If the probability of detecting the same target exceeds P percent in the Nth frame to the N+Wth frame, the radar proceeds to step S3, otherwise it remains in S2; S3: the radar working mode is switched to the second working mode with a high frame rate: the second working mode is maintained for a time of T3; The radar detects the signal in each frame, and detects the distance, speed, and angle information of the target. If the radar does not detect the target within T3 time, it exits the second working mode and returns to S2; if the target can be detected within T3, proceed to step S4; S4: The action of the radar after detecting the target in the second working mode can be set independently; After step S4 is completed, the millimeter wave radar can be set to enter a sleep state, and a sleep time window T4 is set. After T4, the system returns to step S2 to restart detection.

2. A millimeter wave radar target detection method according to claim 1, characterized in that: The calibration mode can partition the area to be tested, and store the distance, speed, and angle information of different areas separately for comparison with subsequent tests.

3. A millimeter wave radar target detection method according to claim 2, characterized in that: Interference information exclusion: Targets continuously detected in S1 are stored as interference signals. When the radar works in the second working mode S3, the stored interference signals are excluded first.

4. A millimeter wave radar target detection method according to claim 3, characterized in that: The step S2 further includes setting the frame period: setting the frame period to M levels, with the frame period of each level gradually increasing; When the radar is started or returns from S3 or S4 to S2: the frame period starts from the first level. If the mode switching condition is not met within the set time period, the frame period is increased step by step according to the time window T2 and the frame rate is reduced.

5. A millimeter wave radar target detection method according to claim 4, characterized in that: The actions after the target is detected in step S4 may include: (1) Track the target. After detecting the target, continue detecting in the next time window T3 until the target is no longer detected in the time window T3, then return to S2; (2) Feedback to the main control unit: Send a signal that the target is detected to the main control unit, return the detection status or issue a command to the controlled device, and the main control or controlled device will take subsequent actions.

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