A tangential motion target detection method and device, electronic equipment and medium

Abstract

This application provides a method, apparatus, electronic device, and medium for detecting tangentially moving targets. When the point cloud detected by millimeter-wave radar for the target is a stationary point cloud, the electronic device can determine the target's absolute velocity relative to the ground based on the measured velocity of the target and the velocity of the stationary target corresponding to a preset number of frames; based on the absolute velocity relative to the ground, determine whether the target meets preset motion conditions; calculate the measured Doppler of the target relative to the ground based on the target's absolute velocity relative to the ground and its azimuth angle; determine whether the polarity of the measured Doppler relative to the ground meets preset polarity conditions based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud; and determine that the target is undergoing tangential motion if the target meets the motion conditions and the polarity of the measured Doppler relative to the ground meets the preset polarity conditions. This allows for the detection of targets undergoing tangential motion.

Description

Technical Field

[0001] This application relates to the field of millimeter-wave radar technology, and in particular to a method, apparatus, electronic device, and medium for detecting tangentially moving targets. Background Technology

[0002] Millimeter-wave radar is a type of radar that detects targets by emitting radar waves in the millimeter-wave band. After receiving the radar echo, the millimeter-wave radar processes the echo using CFAR (Constant False Alarm Rate) to obtain a point cloud corresponding to the detected target. Currently, in related technologies, the prerequisite for millimeter-wave radar to detect moving targets is that the point cloud detected by the millimeter-wave radar is identified as a moving point. Only after the point cloud is identified as a moving point will the moving points be clustered and detected to determine parameters such as the distance and velocity of the detected target relative to the millimeter-wave radar.

[0003] Because of the characteristics of millimeter-wave radar, when a target moves tangentially at any speed along the line connecting the center of the millimeter-wave radar to its radial distance, the measured velocity of the target relative to the ground will be 0. This will cause the point cloud to be misclassified as a stationary point, making it impossible to detect targets moving tangentially. Summary of the Invention

[0004] The purpose of this application is to provide a method, apparatus, electronic device, and medium for detecting tangentially moving targets. The specific technical solution is as follows:

[0005] In a first aspect, embodiments of this application provide a method for detecting a tangentially moving target, the method comprising:

[0006] When the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the absolute velocity relative to the ground corresponding to the target is determined based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time. The velocity of the stationary target is the measured velocity of the stationary target detected by the millimeter-wave radar at the location of the target, and the stationary target is a target that is stationary relative to the ground.

[0007] Based on the absolute velocity relative to the ground, determine whether the target under test meets the preset motion conditions;

[0008] Based on the ground absolute velocity and azimuth angle of the detected target, calculate the ground Doppler corresponding to the detected target;

[0009] Based on the degree of matching between the polarity of the calculated ground-to-ground Doppler and the polarity of the measured ground-to-ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the calculated ground-to-ground Doppler meets the preset polarity condition, wherein the preset polarity condition characterizes whether the detected target has passed through the tangential motion point corresponding to the millimeter-wave radar.

[0010] If the target under test meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target under test has undergone tangential motion.

[0011] Secondly, embodiments of this application provide a detection device for a tangentially moving target, the device comprising:

[0012] The absolute velocity determination module is used to determine the absolute velocity relative to the ground of the detected target when the point cloud detected by the millimeter-wave radar is a stationary point cloud. This is based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target. The stationary target velocity is the measured velocity detected by the millimeter-wave radar of the stationary target at the location of the detected target, and the stationary target is a target that is stationary relative to the ground.

[0013] The motion condition determination module is used to determine whether the detected target meets the preset motion conditions based on the absolute velocity relative to the ground.

[0014] The ground-to-Doppler calculation module is used to calculate the measured ground-to-Doppler of the detected target based on the absolute velocity and azimuth angle of the detected target.

[0015] The polarity condition determination module is used to determine whether the polarity of the measured Doppler meets a preset polarity condition based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud. The preset polarity condition indicates whether the detected target has passed through the tangential motion point corresponding to the millimeter-wave radar.

[0016] The tangential motion determination module is used to determine that the inspected target has undergone tangential motion when the inspected target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions.

[0017] Thirdly, embodiments of this application provide an electronic device, including:

[0018] Memory, used to store computer programs;

[0019] When a processor executes a program stored in memory, it implements the method described in the first aspect above.

[0020] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect above.

[0021] Beneficial effects of the embodiments in this application:

[0022] In the solution provided in this application embodiment, when the point cloud detected by the millimeter-wave radar for the inspected target is a stationary point cloud, the electronic device can determine the ground absolute velocity corresponding to the inspected target based on the measured velocity of the inspected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target. The stationary target velocity is the measured velocity detected by the millimeter-wave radar for a stationary target at the inspected target's location, and the stationary target is a target stationary relative to the ground. Based on the ground absolute velocity, it is determined whether the inspected target meets preset motion conditions. Based on the ground absolute velocity and azimuth angle corresponding to the inspected target, the measured ground Doppler corresponding to the inspected target is calculated. Based on the degree of matching between the polarity of the measured ground Doppler and the polarity of the measured ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the measured ground Doppler meets preset polarity conditions. The preset polarity conditions characterize whether the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar. If the inspected target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the inspected target has undergone tangential motion. Because millimeter-wave radar may misjudge the point cloud corresponding to the inspected target as a stationary point cloud when the inspected target is undergoing tangential motion, electronic equipment can determine the target's absolute velocity relative to the ground when the millimeter-wave radar detects a stationary point cloud. Since the polarity of the calculated and measured Doppler readings changes when the inspected target passes through the tangential motion point corresponding to the millimeter-wave radar, the degree of matching between the calculated and measured Doppler polarities can be used to determine whether the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar, thereby determining whether the calculated Doppler polarity meets a preset polarity condition. If the inspected target meets the preset motion condition, it indicates that the inspected target has actually moved. If the calculated Doppler polarity meets the preset polarity condition, it indicates that the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar. Therefore, when both of the above conditions are met, the electronic device can determine that the target under inspection has undergone tangential motion, thereby realizing the detection of the target under inspection undergoing tangential motion. Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above simultaneously. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0024] Figure 1 A schematic diagram illustrating the tangential motion of the inspected target provided in the embodiments of this application;

[0025] Figure 2 A schematic diagram illustrating a car equipped with millimeter-wave radar turning, as provided in an embodiment of this application.

[0026] Figure 3(a) is a schematic diagram of the inspected target crossing to the right according to an embodiment of this application;

[0027] Figure 3(b) is a schematic diagram of the inspected target crossing to the left according to an embodiment of this application;

[0028] Figure 4 This is a schematic diagram of the azimuth angle detected by the millimeter-wave radar provided in the embodiments of this application;

[0029] Figure 5 A flowchart illustrating a method for detecting a tangentially moving target provided in an embodiment of this application;

[0030] Figure 6 for Figure 5 A specific flowchart of step S503 in the illustrated embodiment;

[0031] Figure 7 For based on Figure 5 The flowchart shown in the embodiment illustrates a method for determining whether a target under test meets preset motion conditions.

[0032] Figure 8 For based on Figure 5 Another flowchart for determining whether the target under test meets the preset motion conditions in the embodiment shown;

[0033] Figure 9 for Figure 5 A specific flowchart of step S505 in the illustrated embodiment;

[0034] Figure 10 for Figure 5 A specific flowchart of step S501 in the illustrated embodiment;

[0035] Figure 11 For based on Figure 5 The illustrated embodiment provides a flowchart for determining the target cluster to which the current frame belongs.

[0036] Figure 12 For based on Figure 5 A flowchart illustrating the determination of target distance in the embodiment shown;

[0037] Figure 13 For based on Figure 5 A schematic diagram of an outlier point in the illustrated embodiment;

[0038] Figure 14(a) shows the results based on... Figure 5 A first schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0039] Figure 14(b) is based on Figure 5 A second schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0040] Figure 14(c) is based on Figure 5 A third schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0041] Figure 14(d) is based on Figure 5 The fourth schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0042] Figure 14(e) is based on Figure 5 The fifth schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0043] Figure 14(f) is based on Figure 5 The sixth schematic diagram of the Doppler polarity distribution in the illustrated embodiment;

[0044] Figure 15 For based on Figure 5 A schematic diagram of a car turning towards a pedestrian in the embodiment shown;

[0045] Figure 16(a) is based on Figure 5 A first schematic diagram of a test scenario in the illustrated embodiment;

[0046] Figure 16(b) is based on Figure 5 A second schematic diagram of the test scenario shown in the embodiment;

[0047] Figure 17 This is a schematic diagram of millimeter-wave radar detection data in current related technologies;

[0048] Figure 18 This is a schematic diagram illustrating the location of pedestrians in current related technologies.

[0049] Figure 19 For based on Figure 5 A schematic diagram of the pedestrian detection location in the illustrated embodiment;

[0050] Figure 20A schematic diagram of the structure of a tangentially moving target detection device provided in an embodiment of this application;

[0051] Figure 21 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0053] To facilitate understanding of this application, the basic principles of this application will be explained below:

[0054] The line connecting the center of the millimeter-wave radar and the target being inspected is the radial direction, and the direction perpendicular to the radial direction is the tangential direction. The following will combine... Figure 1 The radial and tangential directions are explained as follows: the line connecting the center of the millimeter-wave radar 101 and the target 102 is the radial direction. The target 102 moves in a direction perpendicular to the radial direction, and the direction of movement of the target 102 is the tangential direction.

[0055] Millimeter-wave radar periodically emits millimeter-wave radar waves at regular time intervals and performs CFAR processing on the reflected radar echoes to obtain a point cloud corresponding to the detected target. Millimeter-wave radar can determine the following point cloud information: target radial range, measured azimuth, and measured Doppler. Then, motion-stationary separation can be performed based on the point cloud information. The target radial range represents the radial distance between the detected target and the millimeter-wave radar, and the measured Doppler represents the radial velocity of the detected target relative to the millimeter-wave radar.

[0056] Figure 2 A diagram illustrating a car equipped with millimeter-wave radar turning, which will be shown below. Figure 2 The physical quantities of the millimeter-wave radar and the target under inspection are described below. The millimeter-wave radar 201 is installed on the vehicle 202. The longitudinal velocity of the millimeter-wave radar 201 is egoVx, the lateral velocity is egoVy, and the measured azimuth angle is α. The absolute velocity of the target under inspection 203 relative to the ground is V, and the measured Doppler velocity is d.

[0057] Since the longitudinal velocity of the millimeter-wave radar 201 is egoVx and the lateral velocity is egoVy, which are the relative motion velocities of the millimeter-wave radar 201 to the ground, and the measured Doppler d is the radial velocity of the target 203 relative to the millimeter-wave radar 201, the longitudinal velocity egoVx and the lateral velocity egoVy are projected onto the radial direction. By subtracting the projected longitudinal velocity and lateral velocity from the measured Doppler d, the measured ground Doppler of the target 203 can be obtained.

[0058] Expressing the above process using a formula, we can obtain:

[0059] diffDoppler=doppler-(egoVy×sin(azimuth)+egoVx×cos(azimuth));

[0060] Where diffDoppler is the ground-to-ground Doppler measurement, doppler is the measured Doppler, and azimuth is the measured azimuth.

[0061] Next, we will introduce the polarity of Doppler. The polarity of Doppler can be positive, negative, or 0. The polarity is determined as follows: when the absolute value of the Doppler is less than a preset Doppler threshold, the polarity of the Doppler is 0, and the corresponding point cloud is a static point cloud; when the absolute value of the Doppler is not less than the preset Doppler threshold and the Doppler value is positive, the polarity of the Doppler is positive; when the absolute value of the Doppler is not less than the preset Doppler threshold and the Doppler value is negative, the polarity of the Doppler is negative.

[0062] The preset Doppler threshold is greater than 0, for example, it can be 0.1 m / s, 0.2 m / s, 0.3 m / s, etc., without specific limitations. This application will later mention other Doppler measurements such as ground-to-ground Doppler, and the polarity of these Dopplers can be determined using the above method.

[0063] The polarity change of the Doppler signal of the inspected target can be used to reflect the direction of motion of the inspected target relative to the millimeter-wave radar. Specifically, when the direction of the ground-to-ground Doppler is the direction from which the inspected target points to the millimeter-wave radar, the polarity of the ground-to-ground Doppler is negative; when the direction of the ground-to-ground Doppler is the direction from which the millimeter-wave radar points to the inspected target, the polarity of the ground-to-ground Doppler is positive.

[0064] The following explanation will be based on Figures 3(a) and 3(b). Figure 3(a) is a schematic diagram of the inspected target moving to the right. In the left side of Figure 3(a), the inspected target 301 is in the starting position. The millimeter-wave radar 302 is installed at the left front corner of the vehicle 303. Taking the azimuth angle of the X-axis 304 passing through the millimeter-wave radar 302 as 0, the azimuth angle to the left of the X-axis 304 is positive, and the azimuth angle to the right of the X-axis 304 is negative, then the azimuth angle 'a' of the inspected target 301 is positive. Projecting the absolute velocity V of the inspected target 301 to the direction of the line connecting the inspected target 301 to the millimeter-wave radar 302, the measured ground-to-ground Doppler 'd' can be obtained. The polarity of the measured ground-to-ground Doppler 'd' is negative.

[0065] When the target 301 passes through the X-axis 304, it is moving to the right and therefore undergoes tangential motion, resulting in a calculated polarity of the ground-to-ground Doppler d of 0. Before and after the target 301 passes through the X-axis 304, the direction of the decomposition of the target 301's absolute velocity V to the millimeter-wave radar 302 changes, thus altering the calculated polarity of the ground-to-ground Doppler d.

[0066] In Figure 3(a), the target 301 is in the final position, and its azimuth angle β is negative. Projecting the absolute velocity V of the target 301 to the line connecting the target 301 to the millimeter-wave radar 302 yields the calculated ground-to-ground Doppler d, which is positive in polarity. Therefore, as the target 301 moves from left to right, the polarity of its calculated ground-to-ground Doppler changes from negative to 0 and then back to positive.

[0067] Figure 3(b) is a schematic diagram of the inspected target moving to the left. Since the determination method of the azimuth angle and the polarity of the ground-to-Doppler in Figure 3(b) is the same as that in Figure 3(a), the determination method will not be described again below. In the left-hand diagram of Figure 3(b), the inspected target 301 is in the starting position, the azimuth angle β of the inspected target 301 is negative, and the polarity of the measured ground-to-Doppler d is positive. In the right-hand diagram of Figure 3(b), the inspected target 301 is in the ending position, the azimuth angle a of the inspected target 301 is positive, and the polarity of the measured ground-to-Doppler d is negative. It can be seen that when the inspected target 301 moves from right to left, the polarity of the measured ground-to-Doppler of the inspected target will change from positive to 0 and then to negative.

[0068] A schematic diagram of the azimuth angle detected by millimeter-wave radar can be shown as follows: Figure 4 As shown, the azimuth angles detected by the millimeter-wave radar on the left side, from the direction of motion to the opposite direction, are 0°, 90°, and 180° respectively, while the azimuth angles detected by the millimeter-wave radar on the right side, from the direction of motion to the opposite direction, are -0°, -90°, and -180° respectively.

[0069] The measured distance corresponding to the inspected target is the distance between the inspected target and the millimeter-wave radar directly measured by the millimeter-wave radar. The measured distance can be decomposed into longitudinal measured distance and lateral measured distance, corresponding to the direction of motion of the millimeter-wave radar and the direction perpendicular to the direction of motion, respectively. The target distance is the distance between the inspected target and the millimeter-wave radar determined by cyclically removing point clouds identified as outliers. The target distance can be decomposed into longitudinal distance and lateral distance.

[0070] To detect tangentially moving targets, embodiments of this application provide a method, apparatus, electronic device, computer-readable storage medium, and computer program product for detecting tangentially moving targets. The method for detecting tangentially moving targets provided in this application embodiment will be described first below.

[0071] The method for detecting tangentially moving targets provided in this application can be applied to any electronic device that needs to detect tangentially moving targets, such as an in-vehicle processor, processing device, detection device, etc., without specific limitations. For clarity, it will be referred to as an electronic device herein.

[0072] like Figure 5 As shown, a method for detecting a tangentially moving target includes:

[0073] S501, when the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the absolute velocity of the target relative to the ground is determined based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time.

[0074] Wherein, the stationary target velocity is the measured velocity of the stationary target detected by the millimeter-wave radar at the location of the detected target, and the stationary target is a target that is stationary relative to the ground.

[0075] S502, based on the absolute velocity relative to the ground, determine whether the detected target meets the preset motion conditions;

[0076] S503, based on the ground absolute velocity and azimuth angle corresponding to the tested target, calculate the measured ground Doppler corresponding to the tested target;

[0077] S504, based on the degree of matching between the polarity of the calculated ground-to-ground Doppler and the polarity of the measured ground-to-ground Doppler corresponding to the stationary point cloud, determine whether the polarity of the calculated ground-to-ground Doppler meets the preset polarity conditions.

[0078] The preset polarity condition indicates whether the target being inspected has passed through the tangential motion point corresponding to the millimeter-wave radar.

[0079] S505, if the target under test meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target under test has undergone tangential motion.

[0080] As can be seen, in this embodiment of the application, when the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the electronic device can determine the absolute velocity relative to the ground of the target based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time. The stationary target velocity is the measured velocity detected by the millimeter-wave radar for a stationary target at the target's location, and the stationary target is a target stationary relative to the ground. Based on the absolute velocity relative to the ground, it is determined whether the target meets preset motion conditions. Based on the absolute velocity relative to the ground and the azimuth angle of the target, the measured ground Doppler of the target is calculated. Based on the degree of matching between the polarity of the measured ground Doppler and the polarity of the measured ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the measured ground Doppler meets preset polarity conditions. The preset polarity conditions characterize whether the target has passed through the tangential motion point corresponding to the millimeter-wave radar. If the target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target has undergone tangential motion. Because millimeter-wave radar may misjudge the point cloud corresponding to the inspected target as a stationary point cloud when the inspected target is undergoing tangential motion, electronic equipment can determine the target's absolute velocity relative to the ground when the millimeter-wave radar detects a stationary point cloud. Since the polarity of the calculated and measured Doppler readings changes when the inspected target passes through the tangential motion point corresponding to the millimeter-wave radar, the degree of matching between the calculated and measured Doppler polarities can be used to determine whether the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar, thereby determining whether the calculated Doppler polarity meets a preset polarity condition. If the inspected target meets the preset motion condition, it indicates that the inspected target has actually moved. If the calculated Doppler polarity meets the preset polarity condition, it indicates that the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar. Therefore, when both of the above conditions are met, the electronic device can determine that the target being inspected has undergone tangential motion, thereby enabling the detection of the target being inspected in tangential motion.

[0081] Since the millimeter-wave radar may misjudge the point cloud corresponding to the target as a stationary point cloud when the target is undergoing tangential motion, in order to determine whether the target is actually undergoing tangential motion, if the point cloud detected by the millimeter-wave radar is a stationary point cloud, the electronic device can determine the absolute velocity of the target relative to the ground based on the measured velocity of the target corresponding to the most recently detected preset number of frames and the velocity of the stationary target, i.e., execute the above step S501.

[0082] The millimeter-wave radar can be installed on a vehicle or other objects; no specific limitation is made here. The stationary target velocity can be the measured velocity of a stationary target detected by the millimeter-wave radar at the location of the target being inspected. The stationary target can be a target that is stationary relative to the ground. The aforementioned preset number of frames most recently detected can be a preset number of frames included in the target cluster obtained through clustering, including the current frame detected at the current moment.

[0083] If the absolute value of the measured ground-to-ground Doppler for the inspected target is less than the aforementioned preset Doppler threshold, the point cloud detected by the millimeter-wave radar for the inspected target will be determined as a stationary point cloud. In this case, the measured ground-to-ground Doppler for the inspected target may not be zero, but rather have a certain measurement velocity.

[0084] Since the inspected target and the stationary target are in the same position, and the stationary target is stationary relative to the ground, the measured velocity of the inspected target will be greater than the velocity of the stationary target when the inspected target moves relative to the ground. Therefore, the absolute velocity of the inspected target relative to the ground can be determined based on the measured velocity of the inspected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target.

[0085] Since the absolute velocity relative to the ground is the velocity of the target under test relative to the ground, the electronic device can determine whether the target under test meets the preset motion conditions based on the absolute velocity relative to the ground, i.e., execute step S502. The preset motion conditions are one of multiple conditions used to determine whether the target under test undergoes tangential motion.

[0086] Both the calculated and measured polarities of the ground-to-ground Doppler signal reflect the direction of motion of the detected target. The measured ground-to-ground Doppler signal is detected by millimeter-wave radar, so its polarity can be considered the true value. The calculated ground-to-ground Doppler signal is derived from the target's relative absolute velocity and azimuth, so its polarity can be considered a predicted value. If the polarity of the measured and calculated ground-to-ground Doppler signals show a high degree of matching, it indicates that the detected target is indeed moving.

[0087] In step S503, the electronic device can calculate the measured ground-to-ground Doppler based on the absolute velocity and azimuth angle of the target being inspected, i.e., execute step S503. Specifically, the electronic device can project the absolute velocity of the target being inspected onto the line connecting the target being inspected to the center of the millimeter-wave radar according to the azimuth angle of the target being inspected, to obtain the measured ground-to-ground Doppler.

[0088] Next, the electronic device can determine whether the polarity of the measured Doppler meets the preset polarity conditions based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud, i.e., execute step S504.

[0089] The preset polarity condition characterizes whether the target under test has passed through the tangential motion point corresponding to the millimeter-wave radar. The tangential motion point is the point where the target under test is located when it undergoes tangential motion. Since the radial direction between the target under test and the millimeter-wave radar may change in real time as the target under test moves, the tangential motion point corresponding to the millimeter-wave radar may also change in real time as the target under test moves.

[0090] As mentioned earlier, assuming the target passes through a tangential motion point during its movement, the polarity of the measured Doppler signal of the target will change. For example, it may change from positive to 0 and then to negative, or vice versa. Therefore, by calculating the degree of matching between the polarity of the measured Doppler signal and the polarity of the measured Doppler signal corresponding to the stationary point cloud, it can be determined whether the target has passed through the tangential motion point corresponding to the millimeter-wave radar, thereby determining whether the calculated polarity of the measured Doppler signal meets the preset polarity conditions.

[0091] If the detected target meets the preset motion conditions, it indicates that the detected target has actually moved. If the polarity of the measured ground-to-ground Doppler meets the preset polarity conditions, it indicates that the detected target has passed the tangential motion point corresponding to the millimeter-wave radar. Therefore, if both of the above conditions are met, the electronic equipment can determine that the detected target has undergone tangential motion, that is, execute step S505.

[0092] In one implementation, if the number of consecutive frames in which the inspected target undergoes tangential motion exceeds a preset consecutive frame threshold, a trajectory initiation activation can be performed on the tangentially moving inspected target, thereby enabling real-time determination of the target's subsequent position. This solves the problem in current related technologies where trajectory initiation activation for tangentially moving inspected targets is not possible. The preset consecutive frame threshold can be determined according to actual needs, for example, it could be 5, 6, 7, etc.

[0093] As can be seen, in this embodiment, when the target is undergoing tangential movement, the millimeter-wave radar may misjudge the point cloud corresponding to the target as a stationary point cloud. Therefore, to determine whether the target is actually undergoing tangential movement, the electronic device can determine the target's absolute velocity relative to the ground when the millimeter-wave radar detects a stationary point cloud. Since the polarity of the calculated and measured Doppler readings will change when the target passes the tangential movement point corresponding to the millimeter-wave radar, the degree of matching between the calculated Doppler polarity and the measured Doppler polarity corresponding to the stationary point cloud can be used to determine whether the target has passed the tangential movement point corresponding to the millimeter-wave radar, thereby determining whether the calculated Doppler polarity meets a preset polarity condition. If the target meets the preset movement condition, it indicates that the target has actually moved. If the calculated Doppler polarity meets the preset polarity condition, it indicates that the target has passed the tangential movement point corresponding to the millimeter-wave radar. Therefore, when both of the above conditions are met, the electronic device can determine that the target being inspected has undergone tangential motion, thereby enabling the detection of the target being inspected in tangential motion.

[0094] As one embodiment of this application, the step of determining whether the polarity of the measured Doppler meets the preset polarity condition based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud may include:

[0095] For each frame in the preset number of frames, determine whether the polarity of the calculated Doppler signal corresponding to that frame is the same as the polarity of the measured Doppler signal corresponding to that frame, and record the number of identical frames; if the number of frames is not less than a first target preset frame number threshold, determine that the polarity of the calculated Doppler signal meets a preset polarity condition; or,

[0096] Determine whether the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames is consistent with the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames; if the changing trends are consistent, determine that the polarity of the measured Doppler meets the preset polarity condition.

[0097] In the first implementation, assuming that the polarity of the calculated Doppler signal for a frame is the same as the polarity of the measured Doppler signal for that frame, it indicates that the actual motion of the detected target in that frame is the same as the motion obtained through measurement. To improve the accuracy of determining whether the polarity of the calculated Doppler signal meets the preset polarity condition, the electronic device can, for each frame in a preset number of frames, determine whether the polarity of the calculated Doppler signal for that frame is the same as the polarity of the measured Doppler signal for that frame, and record the same number of frames. If the number of recorded frames is not less than the first target preset frame number threshold, the electronic device can determine that the polarity of the calculated Doppler signal meets the preset polarity condition.

[0098] The first target preset frame number threshold can be determined based on the aforementioned preset quantity. Specifically, the first target preset frame number threshold can be the product of the preset quantity and the frame rate ratio. For example, if the preset quantity is 10 and the frame rate ratio is 60%, then the first target preset frame number threshold can be 6. That is, if, within the preset number of frames, there are 6 frames where the polarity of the measured Doppler is the same as the polarity of the measured Doppler in that frame, then the polarity of the measured Doppler will be determined to meet the preset polarity condition.

[0099] Next, the first implementation method described above will be illustrated with an example: Assuming the preset number of frames includes 5 frames, taking the first frame as an example, if the polarity of the calculated Doppler and the polarity of the measured Doppler corresponding to the first frame are positive and negative respectively, then the polarity of the calculated Doppler and the polarity of the measured Doppler corresponding to the first frame are different. Similarly, it can be determined whether the polarity of the calculated Doppler and the polarity of the measured Doppler corresponding to the second to fifth frames are the same. Finally, it is determined that the determination results for the second, third, and fourth frames are the same, and the determination result for the fifth frame is different. If the first target preset frame number threshold is 3, then it can be determined that the polarity of the calculated Doppler meets the preset polarity condition.

[0100] In one implementation, when a frame corresponds to multiple measurement pairs Dopplers, the polarity with the higher proportion among the polarities of the multiple measurement pairs Dopplers in that frame can be determined as the polarity of the measurement pair Doppler corresponding to that frame.

[0101] In the second embodiment, since the trend of change of the polarity of the ground-based Doppler and the trend of change of the polarity of the ground-based Doppler can reflect the direction of motion of the target being measured, if the above trends are consistent, it indicates that the actual direction of motion of the target being measured is the same as the direction of motion obtained by measurement.

[0102] Therefore, the electronic device can determine whether the changing trend of the polarity of the measured Doppler to ground corresponding to a preset number of frames is consistent with the changing trend of the polarity of the measured Doppler to ground corresponding to a preset number of frames. If the changing trends are consistent, it can determine that the polarity of the measured Doppler to ground meets the preset polarity condition. The aforementioned changing trend can be a polarity change process, for example, it can be from positive to 0 and then to negative, or it can be from negative to 0 and then to positive.

[0103] For example, assuming that the trend of the polarity of the measured Doppler corresponding to the preset number of frames is from positive to 0 and then to negative, and the trend of the polarity of the measured Doppler corresponding to the preset number of frames is also from positive to 0 and then to negative, then it can be determined that the polarity of the measured Doppler meets the preset polarity condition.

[0104] As can be seen, in the embodiments of this application, in the first implementation, the polarity of the measured Doppler can be determined based on whether the polarity of the calculated Doppler and the measured Doppler are the same in the same frame, thereby determining whether the polarity of the calculated Doppler meets the preset polarity condition. Since the number of frames with the same polarity of the calculated Doppler and the measured Doppler reflects the degree of consistency between the actual motion of the detected target and the motion obtained through measurement, it is possible to accurately determine whether the polarity of the calculated Doppler meets the preset polarity condition. In the second implementation, the polarity of the measured Doppler can be determined by whether the changing trend of the polarity of the measured Doppler is consistent with the changing trend of the polarity of the measured Doppler in a preset number of frames. Since the changing trends of both the measured and measured Doppler polarities reflect the direction of motion of the detected target, the consistency of these trends also allows for accurate determination of whether the polarity of the measured Doppler meets the preset polarity condition.

[0105] As one implementation method of this application, such as Figure 6 As shown, the steps for calculating the measured Doppler of the ground based on the absolute velocity and azimuth angle of the detected target may include:

[0106] S601, Calculate the average value of the absolute velocity to the ground corresponding to the preset number of frames;

[0107] To improve the accuracy of ground absolute velocity, the electronic device can statistically analyze the ground absolute velocity corresponding to a preset number of frames and calculate the average value of the ground absolute velocity. Specifically, the ground absolute velocity can be decomposed into ground lateral absolute velocity and ground longitudinal absolute velocity, and the electronic device can calculate the average value of the ground lateral absolute velocity corresponding to a preset number of frames and the average value of the ground longitudinal absolute velocity corresponding to a preset number of frames, respectively.

[0108] For example, assuming the pre-screening number of frames includes 10 frames, and the ground absolute velocities corresponding to the 1st to the 10th frames are ground absolute velocity 1 to ground absolute velocity 10 respectively, then the electronic device can calculate the average value of the ground lateral absolute velocity 1 to ground lateral absolute velocity 10, and calculate the average value of the ground longitudinal absolute velocity 1 to ground longitudinal absolute velocity 10.

[0109] S602, Based on the signal-to-noise ratio and azimuth of each point cloud included in the preset number of frames, determine the azimuth corresponding to the preset number of frames;

[0110] Each data frame may include multiple point clouds, including the point cloud corresponding to the inspected target and point clouds corresponding to other targets. Since the signal-to-noise ratio (SNR) of a point cloud is positively correlated with the accuracy of its corresponding azimuth angle, the point cloud with the highest SNR should be the point cloud corresponding to the inspected target. Therefore, the azimuth angle corresponding to the point cloud with the highest SNR is the azimuth angle corresponding to the inspected target.

[0111] To determine the azimuth of the target being inspected, the electronic device can, for each frame in a preset number of frames, determine the azimuth of the point cloud with the highest signal-to-noise ratio included in that data frame, and use this azimuth as the azimuth of that data frame. After determining the azimuth of each frame, the electronic device can store the azimuth of each frame in an array.

[0112] For example, assuming the preset data frame includes 5 frames, taking the first frame as an example, and assuming the first frame includes point clouds 1 to 5, with signal-to-noise ratios (SNRs) of -5dB, 10dB, 14dB, 15dB, and 20dB respectively, then the electronic device can determine that the point cloud with the highest SNR is point cloud 5, and thus determine the azimuth angle corresponding to the first frame as the azimuth angle 5 corresponding to point cloud 5. Similarly, the electronic device can determine the azimuth angles corresponding to the second to fifth frames.

[0113] S603, according to the determined azimuth angle, the average value of the absolute velocity to the ground is projected onto the line connecting the detected target to the center of the millimeter-wave radar to obtain the measured ground Doppler.

[0114] After determining the average value of the absolute velocity to the ground and the azimuth angle, the electronic equipment can project the average value of the absolute velocity to the ground onto the line connecting the target being inspected to the center of the millimeter-wave radar, according to the determined azimuth angle, thereby obtaining the measured ground Doppler.

[0115] The following formula will illustrate the calculation process for measuring the Doppler effect on the ground:

[0116] trackDiffDopplerArray=localVxMean×cos(azimuthArray)+localVyMean×sin(azimuthArray);

[0117] Among them, trackDiffDopplerArray is the measured Doppler array corresponding to a preset number of frames, including the measured Doppler for each frame in the preset number of frames; localVxMean is the average value of the longitudinal absolute velocity of the ground corresponding to the preset number of frames; localVyMean is the average value of the lateral absolute velocity of the ground corresponding to the preset number of frames; and azimuthArray is the azimuth array corresponding to a preset number of frames, including the azimuth for each frame in the preset number of frames.

[0118] As can be seen, in this embodiment, the electronic device can calculate the average value of the absolute velocity to the ground corresponding to a preset number of frames; based on the signal-to-noise ratio and azimuth angle of each point cloud included in the preset number of frames, determine the azimuth angle corresponding to the preset number of frames; according to the determined azimuth angle, project the average value of the absolute velocity to the ground onto the line connecting the detected target to the center of the millimeter-wave radar to obtain the measured ground Doppler. Since the measured ground Doppler is calculated based on the average value of the absolute velocity to the ground corresponding to the preset number of frames and the azimuth angle corresponding to the point cloud with the highest signal-to-noise ratio, the average value of the absolute velocity to the ground corresponding to the preset number of frames can reflect the absolute velocity to the ground of the detected target relatively accurately, and the azimuth angle corresponding to the point cloud with the highest signal-to-noise ratio is also highly accurate. Therefore, the calculated measured ground Doppler is highly accurate.

[0119] As one embodiment of this application, the step of determining whether the detected target meets the preset motion conditions based on the absolute velocity relative to the ground may include:

[0120] From the preset number of frames corresponding to the detected target at the current time, which are the closest to the current time, the number of target frames whose absolute velocity to the ground is greater than a preset target velocity threshold is determined; it is determined whether the number of target frames is greater than a second preset target frame number threshold; if the number of target frames is greater than the second preset target frame number threshold, it is determined that the detected target meets preset motion conditions; and / or,

[0121] The ground absolute velocity is multiplied by the time interval detected by the millimeter-wave radar to obtain the ground motion distance of the detected target; if the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, it is determined that the detected target meets the preset motion conditions.

[0122] In the first implementation, since the detected target has a certain absolute velocity relative to the ground within a certain time period when it actually undergoes tangential motion, the electronic device can determine the number of target frames whose absolute velocity relative to the ground is greater than a preset threshold from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time. The preset threshold for the target's ground velocity can be set according to actual needs, for example, it can be 1 m / s, 1.3 m / s, 1.5 m / s, etc.

[0123] Next, the electronic device can determine whether the target frame count is greater than a second target preset frame count threshold. If the target frame count is greater than the second target preset frame count threshold, it can be determined that the detected target meets the preset motion conditions. If the target frame count is not greater than the second target preset frame count threshold, it can be determined that the detected target does not meet the preset motion conditions. The second target preset frame count threshold can be determined based on a preset quantity. Specifically, the second target preset frame count threshold can be the product of the preset quantity and the aforementioned frame count ratio.

[0124] For example, assuming the preset number of frames includes 5 frames, with corresponding absolute ground velocities of 1.2 m / s, 1.3 m / s, 1.1 m / s, 0.9 m / s, and 1.2 m / s respectively, if the preset ground velocity threshold for the target is 1 m / s, then the target frame count can be determined to be 4. If the preset frame count threshold for the second target is 3, then the detected target can be determined to meet the preset motion conditions.

[0125] In the second implementation, since the detected target will have a certain ground motion distance when it actually undergoes tangential motion, the electronic device can multiply the absolute ground velocity by the time interval detected by the millimeter-wave radar to obtain the ground motion distance corresponding to the detected target. Then, by setting the relationship between the sum of the ground motion distances corresponding to a number of frames and a preset ground distance threshold for the target, it can determine whether the detected target meets the preset motion conditions. Here, the ground motion distance is the distance the detected target moves relative to the ground, and the preset ground distance threshold can be set according to actual needs, for example, it can be 3m, 4m, 5m, etc.

[0126] If the sum of the ground motion distances corresponding to a preset number of frames is greater than a preset ground distance threshold, the electronic device can determine that the detected target meets the preset motion conditions. If the sum of the ground motion distances corresponding to a preset number of frames is not greater than the preset ground distance threshold, the electronic device can determine that the detected target meets the preset motion conditions.

[0127] For example, assuming the preset number of frames includes 5 frames, with corresponding ground motion distances of 0.8m, 1.2m, 1.1m / s, 0.9m, and 1m respectively, then the sum of the ground motion distances corresponding to the preset number of frames can be determined to be 5m. If the preset ground distance threshold for the target is 4m, then it can be determined that the detected target meets the preset motion conditions.

[0128] In the third implementation, the electronic device can execute the first and second implementations described above, and determine that the detected target meets the preset motion conditions when the target number of frames is greater than the second target preset frame number threshold, and the sum of the ground motion distances corresponding to the preset number of frames is greater than the target preset ground distance threshold. Conversely, if the target number of frames is not greater than the second target preset frame number threshold, or the sum of the ground motion distances corresponding to the preset number of frames is not greater than the target preset ground distance threshold, it is determined that the detected target does not meet the preset motion conditions.

[0129] As can be seen, in this embodiment, the electronic device can determine whether the target under test meets the preset motion conditions through the above three methods. Since the target under test will have a certain absolute velocity relative to the ground and a certain distance relative to the ground when it actually undergoes tangential motion, the electronic device can accurately determine whether the target under test meets the preset motion conditions by using the relationship between the number of target frames whose absolute velocity relative to the ground is greater than the target preset ground velocity threshold and the second target preset frame number threshold, and / or the relationship between the sum of the distances relative to the ground corresponding to the preset number of frames and the target preset ground distance threshold.

[0130] As one embodiment of this application, the aforementioned absolute velocity relative to the ground may include both lateral and longitudinal absolute velocities relative to the ground, and the distance traveled relative to the ground may include both lateral and longitudinal distances. In this case, such as Figure 7 As shown, the steps described above, including determining the number of target frames whose absolute ground velocity is greater than a preset ground velocity threshold from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar; determining whether the number of target frames is greater than a second preset target frame number threshold; and determining that the detected target meets preset motion conditions if the number of target frames is greater than the second preset target frame number threshold, may include:

[0131] S701, from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, determine the first number of frames whose lateral absolute velocity to the ground is greater than a preset threshold; if the first number of frames is greater than the first frame number threshold, execute step S702; if the first number of frames is not greater than the first frame number threshold, execute step S703.

[0132] In order to determine whether the target under inspection has undergone lateral movement, the electronic device can determine the number of frames with a ground absolute velocity greater than a preset ground absolute velocity threshold from the preset number of frames corresponding to the target under inspection detected by the millimeter-wave radar. Then, by the relationship between the number of frames and the threshold number, it can determine whether the target under inspection meets the first lateral movement condition.

[0133] The first frame count threshold and the preset ground-to-ground lateral absolute velocity threshold can be determined according to actual needs. Specifically, the first frame count threshold can be the product of a preset number and the frame count ratio. The preset ground-to-ground lateral absolute velocity threshold can be less than the target preset ground-to-ground velocity threshold, for example, it can be 0.5 m / s, 0.6 m / s, and 0.7 m / s, etc.

[0134] S702, determine that the inspected target meets the first lateral movement condition;

[0135] If the number of frames in the first frame is greater than the first frame threshold, the electronic device can determine that the detected target meets the first lateral movement condition. Next, the electronic device can continue to execute step S704.

[0136] For example, assuming the most recent preset number of frames includes 5 frames, with corresponding lateral absolute velocities to the ground of 0.6 m / s, 0.7 m / s, 0.8 m / s, 0.7 m / s, and 0.8 m / s respectively, if the preset lateral absolute velocity threshold to the ground is 0.6 m / s, then the first frame number can be determined to be 4. If the first frame number threshold is 3, then the detected target can be determined to meet the first lateral motion condition.

[0137] S703, determine that the inspected target does not meet the first lateral movement condition;

[0138] If the number of frames in the first frame is not greater than the first frame number threshold, the electronic device can determine that the detected target does not meet the first lateral movement condition. Next, the electronic device can continue to execute step S704.

[0139] S704, from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, determine the number of second frames whose corresponding longitudinal absolute velocity to the ground is greater than a preset threshold; if the number of second frames is greater than the threshold, execute step S705; if the number of second frames is not greater than the threshold, execute step S706.

[0140] In order to determine whether the target under inspection has undergone longitudinal movement, the electronic device can determine the number of second frames from the preset number of frames corresponding to the target under inspection detected by the millimeter-wave radar that are closest to the current time, and the number of frames corresponding to the target under inspection that are greater than the preset threshold for the longitudinal absolute velocity to the ground. Then, by the relationship between the number of second frames and the threshold for the number of second frames, it can determine whether the target under inspection meets the first longitudinal movement condition.

[0141] The second frame count threshold and the preset ground longitudinal absolute velocity threshold can be determined according to actual needs. Specifically, the second frame count threshold can be the product of a preset number and the frame count ratio. The preset ground longitudinal absolute velocity threshold can be less than the target preset ground velocity threshold, for example, it can be 0.5 m / s, 0.6 m / s, and 0.7 m / s, etc.

[0142] S705, determine that the inspected target meets the first longitudinal motion condition;

[0143] If the number of frames in the second frame is greater than the threshold for the number of frames in the second frame, the electronic device can determine that the target being inspected meets the first longitudinal motion condition.

[0144] S706, determine that the inspected target does not meet the first longitudinal motion condition.

[0145] If the second frame count is not greater than a second frame count threshold, the electronic device can determine that the detected target does not meet the first longitudinal motion condition. For example, assuming that the most recent preset number of frames includes 5 frames, with corresponding longitudinal absolute velocities to the ground of 0.4 m / s, 0.5 m / s, 0.6 m / s, 0.7 m / s, and 0.8 m / s respectively, and if the preset lateral absolute velocity threshold to the ground is 0.7 m / s, then the second frame count can be determined to be 1. If the second frame count threshold is 3, then the detected target can be determined to not meet the first longitudinal motion condition.

[0146] Correspondingly, such as Figure 8 As shown, the step of multiplying the absolute velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the ground motion distance corresponding to the detected target; and determining that the detected target meets the preset motion conditions when the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, may include:

[0147] S801, Multiply the absolute lateral velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the lateral movement distance to the ground corresponding to the detected target; if the sum of the lateral movement distances to the ground corresponding to the preset number of frames is greater than the first distance threshold, execute step S802; if the sum of the lateral movement distances to the ground corresponding to the preset number of frames is not greater than the first distance threshold, execute step S803.

[0148] To determine whether the detected target has undergone lateral movement, the electronic device can multiply the absolute lateral velocity relative to the ground by the time interval detected by the millimeter-wave radar to obtain the corresponding lateral movement distance relative to the ground of the detected target. Then, by comparing the sum of the lateral movement distances relative to the ground across a preset number of frames with a first distance threshold, it can determine whether the detected target meets a second lateral movement condition. The first distance threshold can be smaller than the preset ground distance threshold for the target, for example, it can be 2m, 2.5m, or 3m, etc.

[0149] The formula for calculating the lateral movement distance to the ground is: realMoveRy = localVy × frameTime, where realMoveRy is the lateral movement distance to the ground, and frameTime is the aforementioned time interval. In one embodiment, after determining the lateral movement distance to the ground, the lateral movement distance to the ground can be stored in a sliding window.

[0150] S802, determine that the inspected target meets the second lateral movement condition;

[0151] If the sum of the lateral movement distances to the ground corresponding to a preset number of frames is greater than the first distance threshold, the electronic device can determine that the detected target meets the second lateral movement condition. Next, the electronic device can continue to execute step S804.

[0152] S803, determine that the inspected target does not meet the second lateral movement condition;

[0153] If the sum of the lateral movement distances to the ground corresponding to a preset number of frames is not greater than a first distance threshold, the electronic device can determine that the detected target does not meet the second lateral movement condition. Next, the electronic device can continue to execute step S804. For example, assuming that the preset number of frames closest to the current time include 5 frames, with corresponding lateral movement distances to the ground of 0.3m, 0.4m, 0.5m, 0.4m, and 0.4m respectively, then the sum of the lateral movement distances to the ground can be determined to be 2m. If the first distance threshold is 2.5m, then it can be determined that the detected target does not meet the second lateral movement condition.

[0154] S804, Multiply the absolute longitudinal velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the longitudinal motion distance to the ground corresponding to the detected target; if the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is greater than the second distance threshold, execute step S805; if the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is not greater than the second distance threshold, execute step S806.

[0155] To determine whether the detected target has undergone longitudinal movement, the electronic device can multiply the absolute longitudinal velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the corresponding longitudinal movement distance to the ground. Then, by comparing the sum of the longitudinal movement distances to the ground for a preset number of frames with a second distance threshold, it can determine whether the detected target meets the second longitudinal movement condition. The second distance threshold can be smaller than the preset ground distance threshold for the target, for example, it can be 2m, 2.5m, or 3m, etc.

[0156] The formula for calculating the longitudinal movement distance to the ground is: realMoveRx = localVx × frameTime, where realMoveRx is the longitudinal movement distance to the ground. In one embodiment, after determining the longitudinal movement distance to the ground, the longitudinal movement distance to the ground can be stored in a sliding window.

[0157] S805, determine that the inspected target meets the second longitudinal motion condition;

[0158] If the sum of the longitudinal motion distances to the ground corresponding to a preset number of frames is greater than a second distance threshold, the electronic device can determine that the detected target meets the second longitudinal motion condition. For example, assuming that the preset number of frames closest to the current time include 5 frames, with corresponding lateral motion distances to the ground of 0.5m, 0.6m, 0.6m, 0.5m, and 0.6m respectively, then the sum of the longitudinal motion distances to the ground can be determined to be 2.8m. If the second distance threshold is 2.5m, then the detected target can be determined to meet the second longitudinal motion condition.

[0159] S806, determine that the inspected target does not meet the second longitudinal motion condition.

[0160] If the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is not greater than the second distance threshold, the electronic device can determine that the inspected target does not meet the second longitudinal motion condition.

[0161] As can be seen, in this embodiment of the application, through the above implementation methods, the electronic device can determine whether the inspected target meets the lateral movement conditions and the longitudinal movement conditions. In this way, it is possible to quickly and accurately determine whether the inspected target meets the lateral movement conditions and the longitudinal movement conditions.

[0162] As one implementation method of this application, such as Figure 9 As shown, the step of determining that the target under test has undergone tangential motion when the target meets the motion conditions and the polarity of the measured ground-to-ground Doppler meets the preset polarity conditions may include:

[0163] S901, determine whether the target under test meets the first longitudinal motion condition, the second longitudinal motion condition, the first lateral motion condition, and the second lateral motion condition; if the target under test meets the first longitudinal motion condition and the second longitudinal motion condition, and the polarity of the measured Doppler to the ground meets the preset polarity condition, execute step S902; if the target under test meets the first lateral motion condition and the second lateral motion condition, and the polarity of the measured Doppler to the ground meets the preset polarity condition, execute step S903.

[0164] In order to determine whether the inspected target has undergone longitudinal and lateral movement, the electronic device can determine whether the inspected target meets the first longitudinal movement condition, the second longitudinal movement condition, the first lateral movement condition, and the second lateral movement condition.

[0165] S902, determine that the inspected target has undergone longitudinal movement;

[0166] If the target being inspected meets the first longitudinal motion condition and the second longitudinal motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition, the electronic device can determine that the target being inspected has undergone longitudinal motion.

[0167] The determining conditions for the longitudinal movement of the inspected target mentioned above can be expressed as:

[0168] localVxNum > localVxNumThre and realMoveRxSum > realMoveRxSumThre, and diffDopplerPosOrNegArray matches diffDopplerPolarityArray.

[0169] Wherein, localVxNum is the second frame number mentioned above, localVxNumThre is the threshold for the second frame number mentioned above, realMoveRxSum is the sum of the longitudinal motion distance to the ground mentioned above, realMoveRxSumThre is the second distance threshold mentioned above, diffDopplerPosOrNegArray is the polarity of the measured Doppler to the ground mentioned above, and diffDopplerPolarityArray is the polarity of the measured Doppler to the ground mentioned above.

[0170] The matching condition for diffDopplerPosOrNegArray and diffDopplerPolarityArray can be: the number of frames with the same polarity as diffDopplerPosOrNegArray and diffDopplerPolarityArray is not less than polaritySameNumThre, where polaritySameNumThre is the first target preset frame number threshold.

[0171] S903, determine that the inspected target has undergone lateral movement;

[0172] If the target being inspected meets the first and second lateral movement conditions, and the polarity of the measured Doppler reading meets the preset polarity conditions, the electronic device can determine that the target being inspected has undergone lateral movement.

[0173] The determining conditions for the lateral movement of the inspected target mentioned above can be expressed as:

[0174] localVyNum > localVyNumThre and realMoveRySum > realMoveRySumThre, and diffDopplerPosOrNegArray matches diffDopplerPolarityArray.

[0175] Wherein, localVyNum is the first frame number, localVyNumThre is the first frame number threshold, realMoveRySum is the sum of the lateral movement distance to the ground, and realMoveRySumThre is the first distance threshold.

[0176] S904, if the inspected target undergoes longitudinal and / or lateral movement, determine that the inspected target undergoes tangential movement.

[0177] If the inspected target undergoes at least one of longitudinal or lateral motion, it indicates that although the point cloud corresponding to the inspected target is misjudged as a stationary point cloud, the inspected target is actually undergoing tangential motion. Therefore, the electronic device can determine that the inspected target is undergoing tangential motion.

[0178] As can be seen, in this embodiment, the electronic device can determine that the target under test has undergone longitudinal movement when the target meets both the first and second longitudinal movement conditions and the polarity of the measured Doppler reading meets a preset polarity condition; it can determine that the target under test has undergone lateral movement when the target meets both the first and second lateral movement conditions and the polarity of the measured Doppler reading meets a preset polarity condition; and it can determine that the target under test has undergone tangential movement when it undergoes both longitudinal and / or lateral movement. If the target under test undergoes at least one of longitudinal and lateral movement, it indicates that the target under test has actually undergone tangential movement. Through this method, it is possible to quickly and accurately determine whether the target under test has undergone tangential movement.

[0179] As one embodiment of this application, the above-mentioned measurement speed may include lateral measurement speed and longitudinal measurement speed. In this case, such as Figure 10 As shown, the step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target includes:

[0180] S1001, the difference between the linear velocity and the longitudinal linear velocity of the millimeter-wave radar is taken as the longitudinal velocity of the stationary target;

[0181] Since the longitudinal velocity of a stationary target represents the measured velocity of a target stationary relative to the ground, electronic equipment can calculate the longitudinal velocity of a stationary target using the linear velocity, yaw rate, and lateral distance between the millimeter-wave radar and the target. Specifically, the electronic equipment can calculate the product of the millimeter-wave radar's yaw rate and the lateral distance to the target to obtain the longitudinal linear velocity, and then calculate the difference between the millimeter-wave radar's linear velocity and the aforementioned longitudinal linear velocity as the longitudinal velocity of the stationary target.

[0182] The above process can be expressed by the formula: staticVx = egoV - egoYawRate × ry. Where staticVx is the longitudinal velocity of the stationary target, egoV is the linear velocity of the millimeter-wave radar, egoYawRate is the yaw rate, and ry is the lateral distance.

[0183] S1002, the product of the yaw rate and the longitudinal distance corresponding to the detected target is taken as the lateral velocity of the stationary target;

[0184] Electronic devices can use the product of the yaw rate and the corresponding longitudinal distance of the detected target as the lateral velocity of a stationary target. This process can be expressed by the formula: staticVy = egoYawRate × rx, where staticVy is the lateral velocity of the stationary target and rx is the longitudinal distance.

[0185] S1003, calculate the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target to obtain the absolute longitudinal velocity of the target relative to the ground.

[0186] Since the longitudinal velocity of a stationary target is the measured velocity relative to the ground, and the measured longitudinal velocity is the velocity of the target relative to the millimeter-wave radar, in order to determine the target's absolute longitudinal velocity relative to the ground, the electronic equipment can calculate the difference between the measured longitudinal velocity and the stationary target's longitudinal velocity to obtain the target's corresponding absolute longitudinal velocity relative to the ground. Expressing this process using the formula: localVx = vx - staticVx, where localVx is the absolute longitudinal velocity relative to the ground, and vx is the measured longitudinal velocity. In one implementation, after determining the absolute longitudinal velocity relative to the ground, it can be stored in a sliding window.

[0187] S1004, calculate the difference between the lateral measured velocity and the lateral velocity of the stationary target to obtain the ground-based absolute lateral velocity of the inspected target.

[0188] Similarly, to determine the lateral absolute velocity of the inspected target relative to the ground, the electronic device can calculate the difference between the measured lateral velocity and the lateral velocity of the stationary target, thus obtaining the corresponding lateral absolute velocity of the inspected target relative to the ground. Expressing the above process using the formula: localVy = vy - staticVy, where localVy is the lateral absolute velocity relative to the ground, and vy is the measured lateral velocity. In one implementation, after determining the lateral absolute velocity relative to the ground, it can be stored in a sliding window.

[0189] When millimeter-wave radar is installed in a car, the noise of the radar echo received by the millimeter-wave radar is relatively large when the car is turning or the target being detected has a longitudinal movement trend. Therefore, when the car is turning or the target being detected has a longitudinal movement trend, Kalman filtering can be performed on the lateral distance, longitudinal distance, lateral measured speed and longitudinal measured speed determined by the millimeter-wave radar to obtain the lateral distance state value ryStateHat, the longitudinal distance state value rxStateHat, the lateral measured speed state value vyStateHat and the longitudinal measured speed state value vxStateHat.

[0190] In this case, the aforementioned absolute longitudinal velocity relative to the ground can be obtained by subtracting the longitudinal velocity state value from the longitudinal velocity of the stationary target; the aforementioned absolute lateral velocity relative to the ground can be obtained by subtracting the lateral velocity state value from the lateral velocity of the stationary target; the aforementioned longitudinal linear velocity can be obtained by multiplying the yaw rate of the millimeter-wave radar by the lateral distance state value corresponding to the detected target; and the aforementioned lateral velocity of the stationary target can be obtained by multiplying the yaw rate by the longitudinal distance state value.

[0191] As can be seen, in this embodiment, the electronic device can use the difference between the linear velocity and longitudinal linear velocity of the millimeter-wave radar as the longitudinal velocity of the stationary target, where the longitudinal linear velocity is the product of the yaw rate of the millimeter-wave radar and the lateral distance corresponding to the target; the product of the yaw rate and the longitudinal distance corresponding to the target is used as the lateral velocity of the stationary target; the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target is calculated to obtain the longitudinal absolute velocity of the target relative to the ground; the difference between the lateral measured velocity and the lateral velocity of the stationary target is calculated to obtain the lateral absolute velocity of the target relative to the ground. Since the stationary target velocity is the measured velocity of a target stationary relative to the ground, and the measured velocity is the velocity of the target relative to the millimeter-wave radar, the electronic device can calculate the difference between the measured velocity and the stationary target velocity to determine the longitudinal absolute velocity and lateral absolute velocity of the target relative to the ground. This allows for accurate determination of the target's absolute velocity relative to the ground.

[0192] As one embodiment of this application, before the step of calculating the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target to obtain the ground-based absolute velocity of the detected target, the above method may further include:

[0193] Based on the target distance corresponding to the preset number of frames most recently detected at the current moment and the time interval of the millimeter-wave radar detection, the measured velocity corresponding to the detected target is obtained by linear fitting.

[0194] To improve the accuracy of velocity determination, electronic equipment can obtain the velocity of the detected target by linear fitting based on the target distance corresponding to the most recently detected preset number of frames and the time interval of millimeter-wave radar detection. The linear fitting method can be least squares fitting.

[0195] Specifically, the electronic device can fit a straight line corresponding to the lateral measurement speed based on the lateral distance and the aforementioned time interval, and use the slope of the line as the lateral measurement speed. Similarly, the electronic device can fit a straight line corresponding to the longitudinal measurement speed based on the longitudinal distance and the aforementioned time interval, and use the slope of the line as the longitudinal measurement speed.

[0196] In one implementation, the electronic device can store the longitudinal and lateral measurement velocities corresponding to a preset number of frames in a sliding window, with the total number of stored being the preset number.

[0197] The electronic device can also calculate the average distance between the measurement point corresponding to each lateral distance and the line corresponding to the lateral measurement velocity, as the fitting lateral error; and calculate the average distance between the measurement point corresponding to each longitudinal distance and the line corresponding to the longitudinal measurement velocity, as the fitting longitudinal error. The electronic device can store the fitting lateral and longitudinal errors corresponding to a preset number of frames in a sliding window, with the total number of stored errors being the preset number.

[0198] In this case, the fitting lateral error and fitting longitudinal error can be used as criteria to determine whether the detected target has undergone tangential motion. Specifically, based on the preset motion conditions and preset polarity conditions mentioned in the above embodiments, it can be determined whether the fitting lateral error is less than a preset lateral error threshold, and whether the fitting longitudinal error sum corresponding to a preset number of frames is less than a preset longitudinal error threshold.

[0199] If the sum of the fitted lateral errors for a preset number of frames is less than a preset lateral error threshold, and the target meets both the first lateral condition and the second lateral motion condition, then the target is determined to have undergone lateral motion. If the sum of the fitted longitudinal errors for a preset number of frames is less than a preset longitudinal error threshold, and the target meets both the first longitudinal condition and the second longitudinal motion condition, then the target is determined to have undergone longitudinal motion.

[0200] The above judgment conditions can be expressed as: errorVxSum < errorVxSumThre and errorVySum < errorVySumThre. Where errorVxSum is the sum of fitting longitudinal errors for a preset number of frames, errorVxSumThre is a preset longitudinal error threshold, errorVySum is the sum of fitting lateral errors for a preset number of frames, and errorVySumThre is a preset lateral error threshold.

[0201] As can be seen, in this embodiment of the application, the electronic device can obtain the measurement velocity corresponding to the detected target by linear fitting based on the target distance corresponding to the most recently detected preset number of frames and the time interval of millimeter-wave radar detection. In this way, the measurement velocity corresponding to the detected target can be accurately determined.

[0202] As one implementation method of this application, such as Figure 11As shown, prior to the step of determining the absolute velocity of the detected target relative to the ground based on the measured velocity of the detected target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time, the above method may further include:

[0203] S1101, when the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the stationary point cloud is clustered based on the target distance corresponding to the stationary point cloud to obtain the clustering result;

[0204] When the point cloud detected by millimeter-wave radar is a stationary point cloud, in order to determine the target cluster to which the frame corresponding to the stationary point cloud belongs, the electronic device can cluster the stationary point cloud based on the target distance corresponding to the stationary point cloud to obtain the clustering result. As one implementation method, the electronic device can also cluster the stationary point cloud based on the measurement Doppler corresponding to the stationary point cloud to obtain the clustering result.

[0205] S1102, Match the clustering result with the clustering result corresponding to the previous frame;

[0206] Next, the electronic device can match the clustering result with the clustering result of the previous frame. Specifically, it can determine whether the match is successful based on the difference between the clustering result and the clustering result of the previous frame.

[0207] S1103, if the match is successful, add the current frame to the target cluster to which the previous frame belongs.

[0208] If a match is successful, it means that the location of the detected target in the current frame and the location of the detected target in the previous frame belong to the same track. The electronic device can then add the current frame to the target cluster of the previous frame. The target cluster can store a preset number of frames of data, and the specific storage method can be sliding window storage.

[0209] The preset number of frame data may include the azimuth angle, measurement Doppler, and time interval between two adjacent frames of the stationary point cloud corresponding to the preset number of frames.

[0210] Accordingly, the step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time may include:

[0211] Based on the measured velocity of the inspected target and the velocity of the stationary target corresponding to a preset number of frames included in the target cluster, the absolute velocity relative to the ground of the inspected target is determined.

[0212] After determining the target cluster to which the current frame belongs, the electronic device can determine the ground absolute velocity of the detected target based on the measured velocity of the detected target and the velocity of stationary targets in a preset number of frames included in the target cluster. This ensures that the positions of the detected targets in the preset number of frames belong to the same flight path, thereby improving the accuracy of the determined ground absolute velocity.

[0213] As can be seen, in this embodiment, when the point cloud detected by the millimeter-wave radar is a stationary point cloud, the electronic device can cluster the stationary point cloud based on the target distance corresponding to the stationary point cloud to obtain a clustering result; match the clustering result with the clustering result of the previous frame; if the match is successful, add the current frame to the target cluster to which the previous frame belongs, wherein the target cluster stores a preset number of frames of data; and determine the ground absolute velocity of the detected target based on the measured velocity of the detected target and the stationary target velocity corresponding to the preset number of frames included in the target cluster. By clustering, the target cluster to which the current frame belongs can be determined, and then the ground absolute velocity of the detected target can be determined based on the measured velocity of the detected target and the stationary target velocity corresponding to the preset number of frames included in the target cluster. Since the positions of the detected targets corresponding to the preset number of frames belong to the same track, the accuracy of the determined ground absolute velocity can be improved.

[0214] As one implementation method of this application, such as Figure 12 As shown, prior to the step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target and the velocity of the stationary target corresponding to a preset number of frames included in the target clustering, the above method may further include:

[0215] S1201, based on the measurement distances corresponding to the stationary point clouds detected by the millimeter-wave radar for the target being inspected, which are included in the preset number of frames of the target cluster, calculate the average measurement distance and the standard deviation of the measurement distance, and traverse each stationary point cloud.

[0216] Outliers may exist in target clustering, meaning a point that differs significantly from other points. For example, a schematic diagram of outliers could be shown as follows: Figure 13 As shown, outlier 1301 is far from the other points. Electronic devices can calculate the target distance through target clustering, but if there are outliers in the target cluster, the target distance calculated by the target clustering may be biased. Therefore, electronic devices can remove outliers from the target cluster and calculate the target distance based on the remaining points in the target cluster.

[0217] In step S1201, the electronic device can calculate the average measurement distance and the standard deviation of the measurement distance based on the measurement distance corresponding to the stationary point cloud detected by the millimeter-wave radar for the target being inspected, based on the preset number of frames included in the target cluster. Specifically:

[0218] In one implementation, the electronic device can calculate the average lateral measurement distance and the standard deviation of the lateral measurement distance based on the lateral measurement distance corresponding to the stationary point cloud detected by the millimeter-wave radar for the target cluster, which includes a preset number of frames.

[0219] In another implementation, the electronic device can calculate the average longitudinal measurement distance and the standard deviation of the longitudinal measurement distance based on the longitudinal measurement distance corresponding to the stationary point cloud detected by the millimeter-wave radar for the target cluster, which includes a preset number of frames.

[0220] The average measurement distance can include the average lateral measurement distance ryMean and the average longitudinal measurement distance rxMean, and the standard deviation of the measurement distance can include the standard deviation of the lateral measurement distance ryStd and the standard deviation of the longitudinal measurement distance rxStd.

[0221] S1202, For the currently traversed static point cloud, determine the relationship between the absolute value and the product of the static point cloud; if the absolute value is less than the product, execute step S1203; if the absolute value is not less than the product, execute step S1204.

[0222] The electronic device can traverse each stationary point cloud included in the target cluster. For each stationary point cloud traversed, it can determine the relationship between the absolute value and the product corresponding to that stationary point cloud. Here, the absolute value can be the absolute value of the difference between the measured distance and the average measured distance, and the product is the product between the standard deviation of the measured distance and a preset ratio.

[0223] In one implementation, when the measured distance is a longitudinal measured distance, the electronic device can traverse each stationary point cloud included in the target cluster. For each stationary point cloud traversed, the absolute value of the difference between the longitudinal measured distance corresponding to that point cloud and the average longitudinal measured distance is calculated, and the product of the standard deviation of the longitudinal measured distance and a preset ratio is calculated. This determines the relationship between the absolute value and the product corresponding to that stationary point cloud. In this case, the absolute value can be expressed as Abs(rxPoint - rxMean), where rxPoint is the longitudinal measured distance corresponding to the stationary point cloud, and the product can be expressed as rxStd × thre.

[0224] In another implementation, when the measured distance is a lateral measured distance, the electronic device can traverse each stationary point cloud included in the target cluster. For each stationary point cloud traversed, the absolute value of the difference between the lateral measured distance corresponding to that point cloud and the average lateral measured distance is calculated, and the product of the standard deviation of the lateral measured distance and a preset ratio is calculated. This determines the relationship between the absolute value and the product corresponding to that stationary point cloud. In this case, the absolute value can be represented as Abs(ryPoint - ryMean), where ryPoint is the lateral measured distance corresponding to the stationary point cloud, and the product can be represented as ryStd × thre.

[0225] If the absolute value is not less than the product, the stationary point cloud is considered an outlier, and the electronic device can execute step S1204 to determine whether all stationary point clouds have been traversed. If the absolute value is less than the product, the stationary point cloud is considered a non-outlier, and the electronic device can execute step S1203.

[0226] S1203, the measurement distance corresponding to the stationary point cloud is included in the effective measurement distance sum value, and the number of effective point clouds is incremented by 1;

[0227] If the absolute value is less than the product, it indicates that the stationary point cloud is not an outlier. In this case, the electronic device can include the measurement distance corresponding to the stationary point cloud in the effective measurement distance sum and increment the effective point cloud count by 1.

[0228] In one implementation, when the measured distance is a longitudinal measured distance, the electronic device can include the longitudinal measured distance corresponding to the stationary point cloud in the effective longitudinal measured distance sum value and increment the effective longitudinal point cloud count by 1. The effective longitudinal measured distance sum value can be denoted as rxSum, and the effective longitudinal point cloud count can be denoted as countx.

[0229] In another implementation, when the measured distance is a lateral measured distance, the electronic device can include the lateral measured distance corresponding to the stationary point cloud in the effective lateral measured distance sum value and increment the effective lateral point cloud count by 1. The effective lateral measured distance sum value can be denoted as rySum, and the effective lateral point cloud count can be denoted as county.

[0230] S1204, Determine whether all static point clouds have been traversed; if all static point clouds have been traversed, proceed to step S1206; if all static point clouds have not been traversed, proceed to step S1205.

[0231] To determine whether each point cloud in the target cluster is an outlier, the electronic device can determine whether all stationary point clouds have been traversed. If not, the electronic device can execute step S1205 to traverse the next stationary point cloud. If all stationary point clouds have been traversed, the electronic device can execute step S1206.

[0232] S1205, Traverse the next stationary point cloud;

[0233] If all stationary point clouds have not been traversed, the electronic device can traverse the next stationary point cloud and return to step S1202 to determine whether the next stationary point cloud is an outlier.

[0234] S1206, calculate the quotient between the effective measurement distance and the effective point cloud quantity to obtain the target distance.

[0235] After traversing all stationary point clouds, the electronic device can calculate the quotient between the effective measured distance and the effective number of point clouds to obtain the target distance.

[0236] In one implementation, when the measured distance is a longitudinal measured distance, the electronic device can calculate the quotient between the effective longitudinal measured distance sum and the effective longitudinal point cloud count to obtain the longitudinal distance. The formula for calculating the longitudinal distance can be: rx = rxSum / countx.

[0237] In another implementation, when the measured distance is a lateral measured distance, the electronic device can calculate the quotient between the effective lateral measured distance sum and the effective lateral point cloud count to obtain the lateral distance. The formula for calculating the lateral distance can be: ry = rySum / county.

[0238] As can be seen, in this embodiment, the electronic device can calculate the average measurement distance and the standard deviation of the measurement distance based on the measurement distance of the stationary point cloud corresponding to the millimeter-wave radar corresponding to the target cluster, which includes a preset number of frames. It then iterates through each stationary point cloud. For the currently traversed stationary point cloud, it determines the relationship between the absolute value and the product corresponding to that point cloud. The absolute value is the absolute value of the difference between the measured distance and the average measurement distance, and the product is the product of the standard deviation of the measurement distance and a preset ratio. If the absolute value is less than the product, the measurement distance corresponding to that stationary point cloud is included in the effective measurement distance sum, and the number of effective point clouds is incremented by 1. If the absolute value is not less than the product, the next stationary point cloud is traversed, and the step of determining the relationship between the absolute value and the product corresponding to the currently traversed stationary point cloud is returned. This process continues until all stationary point clouds are traversed, and the quotient between the effective measurement distance sum and the number of effective point clouds is calculated to obtain the target distance. Through the above implementation methods, outliers in the target cluster can be removed, and the target distance can be calculated based on the remaining points in the target cluster. This makes the determined target distance more accurate. Unlike the current related technologies that use moving point clouds to determine the position of the inspected target, the method adopted in this application embodiment is to cluster static point clouds and then extract the features of the inspected target from the data detected by the millimeter-wave radar in a preset number of frames, which can accurately determine the inspected target moving tangentially.

[0239] Next, we will use simulation to verify the change in Doppler polarity when the target undergoes tangential motion. The following explanation will be based on the schematic diagrams of the Doppler polarity distribution shown in Figures 14(a)-14(f):

[0240] In the first round of simulation, a dummy can be set as the target to be inspected. The dummy's lateral dimension is 0.6m, its longitudinal dimension is 0.7m, and its absolute velocity relative to the ground is 1m / s. Simulations are performed three times each, with azimuth angles of -90°, -180°, and -135°. Each simulation corresponds to 6 target point clouds, meaning that each simulation generates 6 sets of data. The initial lateral distances of the dummy are 5m, 5.1m, 5m, 5.5m, 4.9m, and 5.2m, respectively, and the initial longitudinal distances are 10m, 10.2m, 9.8m, 10m, 10.5m, and 10.1m, respectively. The schematic diagrams of the Doppler polarity distribution corresponding to the three simulations are shown in Figures 14(a) to 14(c).

[0241] In Figure 14(a), the heading angle is -90°. When the lateral distance is positive, the polarity of the measured ground Doppler is negative. When the lateral distance is around 0, the measured ground Doppler is approximately 0. When the lateral distance is negative, the polarity of the measured ground Doppler is positive.

[0242] In Figure 14(b), the heading angle is -135°. When the lateral distance is greater than -3m, the polarity of the measured ground Doppler is negative. When the lateral distance is -3m and the longitudinal distance is about -3m, the measured ground Doppler is approximately 0. When the lateral distance is less than -3m, the polarity of the measured ground Doppler is positive.

[0243] In Figure 14(c), the heading angle is -180°. When the longitudinal distance is positive, the polarity of the measured ground Doppler is negative. When the longitudinal distance is around 0, the measured ground Doppler is approximately 0. When the longitudinal distance is negative, the polarity of the measured ground Doppler is positive.

[0244] In the second round of simulation, the vehicle can be set as the target, with an absolute ground velocity of 2 m / s. Three simulations are performed with vehicle azimuth angles of 90°, 0°, and 45°, respectively. Each simulation corresponds to a target point cloud of 7 elements. The schematic diagrams of the Doppler polarity distribution for the three simulations are shown in Figures 14(d)-14(f).

[0245] In Figure 14(d), the heading angle is 90°, and the initial lateral distances of the vehicle are -8m, -8m, -12.5m, -12.5m, -10.25m, -9m, and -11.5m, respectively. The initial longitudinal distances are 10m, 12m, 10m, 12m, 11m, 10.5m, and 11.5m, respectively. When the lateral distance is negative, the polarity of the measured Doppler is negative. When the lateral distance is around 0, the measured Doppler is approximately 0. When the lateral distance is positive, the polarity of the measured Doppler is positive.

[0246] In Figure 14(e), the heading angle is 45°, and the initial lateral distances of the vehicle are -8m, -9.14m, -12.32m, -10.9m, -10.25m, -9m, and -11.5m, respectively. The initial longitudinal distances are -6.41m, -5m, -8.18m, -9.59m, -6m, -5.5m, and -5.5m, respectively. When the lateral distance is negative, the polarity of the measured Doppler is negative. When the lateral distance is 2m and the longitudinal distance is about -2m, the measured Doppler is approximately 0. When the lateral distance is positive, the polarity of the measured Doppler is positive.

[0247] In Figure 14(f), the heading angle is 0°, and the initial lateral distances of the vehicle are 10m, 12m, 10m, 12m, 11m, 10.5m, and 11.5m, respectively. The initial longitudinal distances are -8m, -8m, -12.5m, -12.5m, -10.25m, -9m, and -11.5m, respectively. When the polarity of the longitudinal distance is negative, the polarity of the measured Doppler is negative. When the longitudinal distance is around 0, the measured Doppler is approximately 0. When the longitudinal distance is positive, the polarity of the measured Doppler is positive.

[0248] Simulation results show that the polarity of the measured ground-to-ground Doppler varies depending on the target's direction of motion. When the angle between the azimuth and the line connecting the target's position to the center of the millimeter-wave radar is 90°, the measured ground-to-ground Doppler is approximately zero. Assuming the target's direction of motion is uniform, the polarity of the measured ground-to-ground Doppler changes before and after the target undergoes tangential motion. Therefore, to determine whether the target is undergoing tangential motion, the polarity of the measured ground-to-ground Doppler can be determined based on the azimuth and the absolute velocity relative to the ground, and then compared with the calculated ground-to-ground Doppler polarity.

[0249] A diagram illustrating a car-to-pedestrian turning adult (CPTA) scenario can be shown as follows: Figure 15 As shown, the initial direction of movement of car 1501 is 1.75m away from the center line 1502 of the road. Car 1501 makes three turns at speeds of 10km / h, 15km / h, and 20km / h respectively. Pedestrian 1503 starts moving simultaneously with car 1501 at a speed of 1m / s. The initial position of pedestrian 1503 is 9.50m away from the completed path of the car, and the distance between the pedestrian's path and the center line 1502 is also 9.50m. Without applying braking to car 1501, car 1501 will collide with pedestrian 1503 at 50% of its width. In this scenario, pedestrian 1503 needs to be detected to prevent a collision.

[0250] The schematic diagrams of the test scenario obtained by the construction are shown in Figure 16(a) and Figure 16(b). In Figure 16(a), car 1601 is at the starting position, and car 1601 is far away from pedestrian 1602. In Figure 16(b), car 1601 is turning, and car 1601 is close to pedestrian 1602.

[0251] Currently, in related technologies, a schematic diagram of millimeter-wave radar detection data for automobiles in the aforementioned scenarios can be shown as follows: Figure 17As shown, the window is named "Large Point Cloud" and includes several options below: Large Point Cloud, Clustering, Obstacle Information, Track, Point Cloud, Vehicle Speed ​​Buffer, and Number of Interference Points. The currently displayed interface is for the Large Point Cloud, specifically including the point cloud index number, associated sensor, associated cluster, associated track, signal-to-noise ratio, latitude, longitude, altitude, range, azimuth, Doppler measurement, motion attribute, mapping value, and specific data for each parameter. Since a moving target is only detected when the absolute value of the Doppler measurement is greater than 0.3 m / s, and the absolute values ​​of the Doppler measurements in the image are all less than 0.3 m / s, the point cloud corresponding to the pedestrian will be classified as a stationary point cloud, thus preventing the initiation of a moving target detection.

[0252] In this case, a diagram illustrating the pedestrian detection location can be as follows: Figure 18 As shown, the black dots represent the detected locations of pedestrians. Since it is impossible to initiate movement for pedestrians, the black dots are all separate and no pedestrian movement track is formed.

[0253] After adding a tangential motion target initiation module to the vehicle, that is, after applying the method provided in the embodiments of this application, the schematic diagram of the pedestrian detection location can be as follows: Figure 19 As shown, when the pedestrian is at the first position 1901, the millimeter-wave radar detects that the pedestrian's lateral velocity is -1.2 m / s and the longitudinal velocity is 0.33 m / s. The moving target initiation for the pedestrian is successfully completed at the first position 1901, and the pedestrian's subsequent trajectory 1902 can be determined. Therefore, the method provided in this application embodiment can achieve the detection of tangentially moving targets.

[0254] In the technical solution of this application, the operations of obtaining, storing, using, processing, transmitting, providing and disclosing user personal information are all carried out with the user's authorization.

[0255] like Figure 20 As shown, a detection device for a tangentially moving target includes:

[0256] The absolute velocity determination module 2001 is used to determine the absolute velocity relative to the ground of the detected target when the point cloud detected by the millimeter-wave radar is a stationary point cloud, based on the measured velocity of the detected target corresponding to the preset number of frames most recently detected at the current time and the velocity of the stationary target. The stationary target velocity is the measured velocity detected by the millimeter-wave radar of the stationary target at the location of the detected target, and the stationary target is a target that is stationary relative to the ground.

[0257] The motion condition determination module 2002 is used to determine whether the detected target meets the preset motion conditions based on the absolute velocity relative to the ground.

[0258] The ground-to-Doppler calculation module 2003 is used to calculate the measured ground-to-Doppler of the detected target based on the absolute velocity and azimuth angle of the detected target.

[0259] The polarity condition determination module 2004 is used to determine whether the polarity of the measured Doppler meets the preset polarity condition based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud. The preset polarity condition characterizes whether the detected target has passed through the tangential motion point corresponding to the millimeter-wave radar.

[0260] The tangential motion determination module 2005 is used to determine that the target under test has undergone tangential motion when the target under test meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions.

[0261] As can be seen, in this embodiment of the application, when the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the electronic device can determine the absolute velocity relative to the ground of the target based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time. The stationary target velocity is the measured velocity detected by the millimeter-wave radar for a stationary target at the target's location, and the stationary target is a target stationary relative to the ground. Based on the absolute velocity relative to the ground, it is determined whether the target meets preset motion conditions. Based on the absolute velocity relative to the ground and the azimuth angle of the target, the measured ground Doppler of the target is calculated. Based on the degree of matching between the polarity of the measured ground Doppler and the polarity of the measured ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the measured ground Doppler meets preset polarity conditions. The preset polarity conditions characterize whether the target has passed through the tangential motion point corresponding to the millimeter-wave radar. If the target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target has undergone tangential motion. Because millimeter-wave radar may misjudge the point cloud corresponding to the inspected target as a stationary point cloud when the inspected target is undergoing tangential motion, electronic equipment can determine the target's absolute velocity relative to the ground when the millimeter-wave radar detects a stationary point cloud. Since the polarity of the calculated and measured Doppler readings changes when the inspected target passes through the tangential motion point corresponding to the millimeter-wave radar, the degree of matching between the calculated and measured Doppler polarities can be used to determine whether the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar, thereby determining whether the calculated Doppler polarity meets a preset polarity condition. If the inspected target meets the preset motion condition, it indicates that the inspected target has actually moved. If the calculated Doppler polarity meets the preset polarity condition, it indicates that the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar. Therefore, when both of the above conditions are met, the electronic device can determine that the target being inspected has undergone tangential motion, thereby enabling the detection of the target being inspected in tangential motion.

[0262] As one embodiment of this application, the polarity condition determination module 2004 may include:

[0263] The first polarity condition determination submodule is used to determine, for each frame in the preset number of frames, whether the polarity of the measured Doppler corresponding to that frame is the same as the polarity of the measured Doppler corresponding to that frame, and record the number of the same frames; if the number of frames is not less than the first target preset frame number threshold, determine that the polarity of the measured Doppler meets the preset polarity condition.

[0264] The second polarity condition determination submodule is used to determine whether the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames is consistent with the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames; if the changing trends are consistent, it is determined that the polarity of the measured Doppler meets the preset polarity condition.

[0265] As one embodiment of this application, the above-described Doppler calculation module 2003 may include:

[0266] The average value calculation submodule is used to calculate the average value of the absolute velocity to the ground corresponding to the preset number of frames;

[0267] The azimuth angle determination submodule is used to determine the azimuth angle corresponding to the preset number of frames based on the signal-to-noise ratio and azimuth angle of each point cloud included in the preset number of frames.

[0268] The ground-to-Doppler determination submodule is used to project the average value of the absolute velocity to the ground onto the line connecting the detected target to the center of the millimeter-wave radar according to the determined azimuth angle, so as to obtain the measured ground-to-Doppler.

[0269] As one embodiment of this application, the motion condition determination module 2002 described above may include:

[0270] The first motion condition determination submodule is used to determine, from the preset number of frames corresponding to the detected target at the current time, the number of target frames whose absolute velocity to the ground is greater than a preset threshold for the target; determine whether the number of target frames is greater than a second preset threshold for the number of target frames; and determine that the detected target meets the preset motion conditions if the number of target frames is greater than the second preset threshold for the number of target frames.

[0271] The second motion condition determination submodule is used to multiply the absolute velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the ground motion distance corresponding to the detected target; if the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, the detected target is determined to meet the preset motion conditions.

[0272] As one embodiment of this application, the aforementioned absolute velocity relative to the ground may include both lateral absolute velocity and longitudinal absolute velocity relative to the ground, and the distance traveled relative to the ground may include both lateral and longitudinal distance traveled relative to the ground. In this case, the aforementioned first motion condition determination submodule may include:

[0273] The first frame number determination unit is used to determine the first frame number corresponding to the ground lateral absolute velocity being greater than a preset ground lateral absolute velocity threshold from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time.

[0274] The first lateral motion condition determination unit is used to determine that the detected target meets the first lateral motion condition when the first frame number is greater than the first frame number threshold.

[0275] The second frame number determination unit is used to determine the number of second frames from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, where the corresponding longitudinal absolute velocity to the ground is greater than a preset threshold.

[0276] The first longitudinal motion condition determination unit is used to determine that the detected target meets the first longitudinal motion condition when the second frame number is greater than the second frame number threshold.

[0277] Accordingly, the aforementioned second motion condition determination submodule may include:

[0278] The lateral motion distance determination unit is used to multiply the absolute lateral velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the lateral motion distance to the ground corresponding to the detected target.

[0279] The second lateral motion condition determination unit is used to determine that the detected target meets the second lateral motion condition when the sum of the ground lateral motion distances corresponding to the preset number of frames is greater than the first distance threshold.

[0280] The longitudinal motion distance determination unit is used to multiply the absolute longitudinal velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the longitudinal motion distance to the ground corresponding to the detected target.

[0281] The second longitudinal motion condition determination unit is used to determine that the detected target meets the second longitudinal motion condition when the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is greater than the second distance threshold.

[0282] As one embodiment of this application, the tangential motion determination module 2005 described above may include:

[0283] The longitudinal motion determination submodule is used to determine that the inspected target has undergone longitudinal motion when the inspected target meets the first longitudinal motion condition and the second longitudinal motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition.

[0284] The lateral motion determination submodule is used to determine that the inspected target has undergone lateral motion when the inspected target meets the first lateral motion condition and the second lateral motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition.

[0285] The tangential motion determination submodule is used to determine that the inspected target has undergone tangential motion when the inspected target undergoes longitudinal and / or lateral motion.

[0286] As one embodiment of this application, the above-mentioned speed measurement may include lateral speed measurement and longitudinal speed measurement. In this case, the above-mentioned absolute speed determination module 2001 may include:

[0287] The stationary target longitudinal velocity determination submodule is used to take the difference between the linear velocity of the millimeter-wave radar and the longitudinal linear velocity as the stationary target longitudinal velocity, wherein the longitudinal linear velocity is the product of the yaw rate of the millimeter-wave radar and the lateral distance corresponding to the detected target;

[0288] The stationary target lateral velocity determination submodule is used to take the product of the yaw rate and the longitudinal distance corresponding to the detected target as the stationary target lateral velocity.

[0289] The longitudinal absolute velocity determination submodule is used to calculate the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target to obtain the longitudinal absolute velocity of the detected target relative to the ground.

[0290] The lateral absolute velocity determination submodule is used to calculate the difference between the lateral measured velocity and the lateral velocity of the stationary target to obtain the ground-based lateral absolute velocity of the inspected target.

[0291] As one embodiment of this application, the above-described apparatus may further include:

[0292] The velocity measurement fitting module is used to obtain the velocity measurement of the detected target by linear fitting based on the target distance corresponding to the most recently detected preset number of frames at the current time and the time interval of the millimeter-wave radar detection.

[0293] As one embodiment of this application, the above-described apparatus may further include:

[0294] The stationary point cloud clustering module is used to cluster the stationary point cloud based on the target distance corresponding to the stationary point cloud when the point cloud detected by the millimeter-wave radar is a stationary point cloud, and obtain the clustering result.

[0295] The clustering result matching module is used to match the clustering result with the clustering result corresponding to the previous frame;

[0296] The target clustering determination module is used to add the current frame to the target cluster to which the previous frame belongs when a match is successful, wherein the target cluster stores a preset number of frame data;

[0297] Accordingly, the absolute velocity determination module 2001 mentioned above may include:

[0298] The absolute velocity determination submodule is used to determine the ground absolute velocity of the inspected target based on the measured velocity of the inspected target and the velocity of the stationary target corresponding to a preset number of frames included in the target cluster.

[0299] As one embodiment of this application, the above-described apparatus may further include:

[0300] The parameter calculation module is used to calculate the average measurement distance and the standard deviation of the measurement distance based on the measurement distance of the stationary point cloud detected by the millimeter-wave radar corresponding to the preset number of frames included in the target cluster, and to traverse each stationary point cloud.

[0301] The point cloud traversal module is used to determine the relationship between the absolute value and the product of the current stationary point cloud being traversed. The absolute value is the absolute value of the difference between the measured distance and the average value of the measured distance, and the product is the product between the standard deviation of the measured distance and a preset ratio.

[0302] The counting module is used to include the measurement distance corresponding to the stationary point cloud into the effective measurement distance sum value when the absolute value is less than the product, and to increment the number of effective point clouds by 1;

[0303] The termination condition determination module is used to determine whether all static point clouds have been traversed if the absolute value is not less than the product.

[0304] The return module is used to traverse the next static point cloud before all static point clouds have been traversed, and to trigger the point cloud traversal module.

[0305] The target distance determination module is used to calculate the quotient between the effective measured distance and the number of effective point clouds after traversing all stationary point clouds, and obtain the target distance.

[0306] This application also provides an electronic device, such as... Figure 21 As shown, it includes:

[0307] Memory 2101 is used to store computer programs;

[0308] The processor 2102 is used to execute the program stored in the memory 2101 to implement the tangential moving target detection method described in any of the above embodiments.

[0309] As can be seen, in this embodiment of the application, when the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the electronic device can determine the absolute velocity relative to the ground of the target based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time. The stationary target velocity is the measured velocity detected by the millimeter-wave radar for a stationary target at the target's location, and the stationary target is a target stationary relative to the ground. Based on the absolute velocity relative to the ground, it is determined whether the target meets preset motion conditions. Based on the absolute velocity relative to the ground and the azimuth angle of the target, the measured ground Doppler of the target is calculated. Based on the degree of matching between the polarity of the measured ground Doppler and the polarity of the measured ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the measured ground Doppler meets preset polarity conditions. The preset polarity conditions characterize whether the target has passed through the tangential motion point corresponding to the millimeter-wave radar. If the target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target has undergone tangential motion. Because millimeter-wave radar may misjudge the point cloud corresponding to the inspected target as a stationary point cloud when the inspected target is undergoing tangential motion, electronic equipment can determine the target's absolute velocity relative to the ground when the millimeter-wave radar detects a stationary point cloud. Since the polarity of the calculated and measured Doppler readings changes when the inspected target passes through the tangential motion point corresponding to the millimeter-wave radar, the degree of matching between the calculated and measured Doppler polarities can be used to determine whether the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar, thereby determining whether the calculated Doppler polarity meets a preset polarity condition. If the inspected target meets the preset motion condition, it indicates that the inspected target has actually moved. If the calculated Doppler polarity meets the preset polarity condition, it indicates that the inspected target has passed through the tangential motion point corresponding to the millimeter-wave radar. Therefore, when both of the above conditions are met, the electronic device can determine that the target being inspected has undergone tangential motion, thereby enabling the detection of the target being inspected in tangential motion.

[0310] Furthermore, the aforementioned electronic device may also include a communication bus and / or a communication interface, with the processor 2102, the communication interface, and the memory 2101 communicating with each other via the communication bus.

[0311] The communication bus mentioned in the above electronic devices can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0312] The communication interface is used for communication between the aforementioned electronic devices and other devices.

[0313] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0314] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0315] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of the above-described method for detecting any tangential moving target.

[0316] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the tangential moving target detection methods in the above embodiments.

[0317] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a solid-state drive (SSD), etc.

[0318] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0319] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, electronic devices, computer-readable storage media, and computer program products are basically similar to the method embodiments, and therefore the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0320] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A method for detecting a tangentially moving target, characterized in that, The method includes: When the point cloud detected by the millimeter-wave radar for the target is a stationary point cloud, the absolute velocity relative to the ground corresponding to the target is determined based on the measured velocity of the target and the velocity of the stationary target corresponding to the most recently detected preset number of frames at the current time. The velocity of the stationary target is the measured velocity of the stationary target detected by the millimeter-wave radar at the location of the target, and the stationary target is a target that is stationary relative to the ground. Based on the absolute velocity relative to the ground, determine whether the target under test meets the preset motion conditions; Based on the ground absolute velocity and azimuth angle of the detected target, calculate the ground Doppler corresponding to the detected target; Based on the degree of matching between the polarity of the calculated ground-to-ground Doppler and the polarity of the measured ground-to-ground Doppler corresponding to the stationary point cloud, it is determined whether the polarity of the calculated ground-to-ground Doppler meets the preset polarity condition, wherein the preset polarity condition characterizes whether the detected target has passed through the tangential motion point corresponding to the millimeter-wave radar. If the target under test meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions, it is determined that the target under test has undergone tangential motion.

2. The method according to claim 1, characterized in that, The step of determining whether the polarity of the measured Doppler meets the preset polarity conditions based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud includes: For each frame in the preset number of frames, determine whether the polarity of the calculated Doppler signal corresponding to that frame is the same as the polarity of the measured Doppler signal corresponding to that frame, and record the number of identical frames; if the number of frames is not less than a first target preset frame number threshold, determine that the polarity of the calculated Doppler signal meets a preset polarity condition; or, Determine whether the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames is consistent with the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames; if the changing trends are consistent, determine that the polarity of the measured Doppler meets the preset polarity condition.

3. The method according to claim 1, characterized in that, The step of calculating the measured ground Doppler based on the ground absolute velocity and azimuth angle of the detected target includes: Calculate the average value of the absolute velocity to the ground corresponding to the preset number of frames; Based on the signal-to-noise ratio and azimuth of each point cloud included in the preset number of frames, the azimuth corresponding to the preset number of frames is determined. Based on the determined azimuth angle, the average value of the absolute velocity to the ground is projected onto the line connecting the detected target to the center of the millimeter-wave radar to obtain the measured ground Doppler.

4. The method according to claim 1, characterized in that, The step of determining whether the detected target meets the preset motion conditions based on the absolute velocity relative to the ground includes: From the preset number of frames corresponding to the detected target at the current time, which are the closest to the current time, the number of target frames whose absolute velocity to the ground is greater than a preset target velocity threshold is determined; it is determined whether the number of target frames is greater than a second preset target frame number threshold; if the number of target frames is greater than the second preset target frame number threshold, it is determined that the detected target meets preset motion conditions; and / or, The ground absolute velocity is multiplied by the time interval detected by the millimeter-wave radar to obtain the ground motion distance of the detected target; if the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, it is determined that the detected target meets the preset motion conditions.

5. The method according to claim 4, characterized in that, The absolute velocity relative to the ground includes the lateral absolute velocity relative to the ground and the longitudinal absolute velocity relative to the ground, and the distance of motion relative to the ground includes the lateral distance of motion relative to the ground and the longitudinal distance of motion relative to the ground. The step involves determining the number of target frames whose absolute ground velocity is greater than a preset ground velocity threshold from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar at the current time; and determining whether the number of target frames is greater than a second preset target frame number threshold. The step of determining that the detected target meets preset motion conditions when the target frame number is greater than the second target preset frame number threshold includes: From the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, determine the first frame number whose corresponding ground lateral absolute velocity is greater than a preset ground lateral absolute velocity threshold. If the first frame number is greater than the first frame number threshold, it is determined that the detected target meets the first lateral motion condition; From the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, determine the number of second frames whose corresponding longitudinal absolute velocity to the ground is greater than a preset threshold. If the second frame number is greater than the second frame number threshold, it is determined that the detected target meets the first longitudinal motion condition; The step of multiplying the absolute velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the ground motion distance corresponding to the detected target; and determining that the detected target meets the preset motion conditions when the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, includes: Multiplying the absolute lateral velocity relative to the ground by the time interval detected by the millimeter-wave radar yields the lateral distance of the detected target relative to the ground. If the sum of the lateral movement distances to the ground corresponding to the preset number of frames is greater than the first distance threshold, it is determined that the detected target meets the second lateral movement condition. Multiplying the absolute longitudinal velocity relative to the ground by the time interval detected by the millimeter-wave radar yields the longitudinal distance of the detected target relative to the ground. If the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is greater than the second distance threshold, the detected target is determined to meet the second longitudinal motion condition.

6. The method according to claim 5, characterized in that, The step of determining that the target under test has undergone tangential motion, provided that the target meets the motion conditions and the polarity of the measured Doppler reading meets the preset polarity conditions, includes: If the inspected target meets the first longitudinal motion condition and the second longitudinal motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition, it is determined that the inspected target has undergone longitudinal motion. If the inspected target meets the first lateral movement condition and the second lateral movement condition, and the polarity of the measured ground-to-ground Doppler meets the preset polarity condition, it is determined that the inspected target has undergone lateral movement. If the inspected target undergoes longitudinal and / or lateral movement, it is determined that the inspected target has undergone tangential movement.

7. The method according to any one of claims 1-6, characterized in that, The measurement speed includes lateral measurement speed and longitudinal measurement speed; The step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target includes: The difference between the linear velocity and the longitudinal linear velocity of the millimeter-wave radar is taken as the longitudinal velocity of the stationary target, wherein the longitudinal linear velocity is the product of the yaw rate of the millimeter-wave radar and the lateral distance corresponding to the detected target. The product of the yaw rate and the longitudinal distance corresponding to the detected target is taken as the lateral velocity of the stationary target. The difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target is calculated to obtain the absolute longitudinal velocity of the target relative to the ground. The difference between the measured lateral velocity and the lateral velocity of the stationary target is calculated to obtain the absolute lateral velocity relative to the ground of the target under test.

8. The method according to claim 7, characterized in that, Before the step of calculating the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target to obtain the corresponding absolute longitudinal velocity of the detected target relative to the ground, the method further includes: Based on the target distance corresponding to the preset number of frames most recently detected at the current moment and the time interval of the millimeter-wave radar detection, the measured velocity corresponding to the detected target is obtained by linear fitting.

9. The method according to any one of claims 1-6, characterized in that, Before the step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target, the method further includes: When the point cloud detected by the millimeter-wave radar is a stationary point cloud, the stationary point cloud is clustered based on the target distance corresponding to the stationary point cloud to obtain the clustering result; The clustering result is matched with the clustering result of the previous frame; If a match is successful, the current frame is added to the target cluster to which the previous frame belongs, wherein the target cluster stores a preset number of frame data; The step of determining the absolute velocity relative to the ground of the detected target based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target includes: Based on the measured velocity of the inspected target and the velocity of the stationary target corresponding to a preset number of frames included in the target cluster, the absolute velocity relative to the ground of the inspected target is determined.

10. The method according to claim 9, characterized in that, Before the step of determining the ground absolute velocity of the detected target based on the measured velocity of the detected target and the velocity of the stationary target corresponding to a preset number of frames included in the target cluster, the method further includes: Based on the measured distances of the stationary point clouds detected by the millimeter-wave radar for the target being inspected, corresponding to a preset number of frames included in the target cluster, the average measured distance and the standard deviation of the measured distance are calculated, and each stationary point cloud is traversed. For the currently traversed static point cloud, determine the relationship between the absolute value and the product corresponding to the static point cloud, wherein the absolute value is the absolute value of the difference between the measured distance and the average value of the measured distance, and the product is the product between the standard deviation of the measured distance and a preset ratio; If the absolute value is less than the product, the measurement distance corresponding to the stationary point cloud is included in the effective measurement distance and value, and the number of effective point clouds is incremented by 1. If the absolute value is not less than the product, determine whether to traverse all stationary point clouds. If not all static point clouds have been traversed, traverse the next static point cloud and return the step of determining the relationship between the absolute value and the product of the current static point cloud. After traversing all stationary point clouds, the quotient between the sum of the effective measured distances and the number of effective point clouds is calculated to obtain the target distance.

11. A detection device for a tangentially moving target, characterized in that, The device includes: The absolute velocity determination module is used to determine the absolute velocity relative to the ground of the detected target when the point cloud detected by the millimeter-wave radar is a stationary point cloud. This is based on the measured velocity of the detected target corresponding to the most recently detected preset number of frames and the velocity of the stationary target. The stationary target velocity is the measured velocity detected by the millimeter-wave radar of the stationary target at the location of the detected target, and the stationary target is a target that is stationary relative to the ground. The motion condition determination module is used to determine whether the detected target meets the preset motion conditions based on the absolute velocity relative to the ground. The ground-to-Doppler calculation module is used to calculate the measured ground-to-Doppler of the detected target based on the absolute velocity and azimuth angle of the detected target. The polarity condition determination module is used to determine whether the polarity of the measured Doppler meets a preset polarity condition based on the degree of matching between the polarity of the measured Doppler and the polarity of the measured Doppler corresponding to the stationary point cloud. The preset polarity condition indicates whether the detected target has passed through the tangential motion point corresponding to the millimeter-wave radar. The tangential motion determination module is used to determine that the inspected target has undergone tangential motion when the inspected target meets the motion conditions and the polarity of the measured ground Doppler meets the preset polarity conditions.

12. The apparatus according to claim 11, characterized in that, The polarity condition determination module includes: The first polarity condition determination submodule is used to determine, for each frame in the preset number of frames, whether the polarity of the measured Doppler corresponding to that frame is the same as the polarity of the measured Doppler corresponding to that frame, and record the number of the same frames; if the number of frames is not less than the first target preset frame number threshold, determine that the polarity of the measured Doppler meets the preset polarity condition. The second polarity condition determination submodule is used to determine whether the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames is consistent with the changing trend of the polarity of the measured Doppler corresponding to the preset number of frames; if the changing trends are consistent, it is determined that the polarity of the measured Doppler meets the preset polarity condition; and / or, The ground-based Doppler calculation module includes: The average value calculation submodule is used to calculate the average value of the absolute velocity to the ground corresponding to the preset number of frames; The azimuth angle determination submodule is used to determine the azimuth angle corresponding to the preset number of frames based on the signal-to-noise ratio and azimuth angle of each point cloud included in the preset number of frames. A ground-to-ground Doppler determination submodule is used to project the average value of the absolute velocity relative to the ground onto the line connecting the detected target to the center of the millimeter-wave radar, according to the determined azimuth angle, to obtain the calculated ground-to-ground Doppler; and / or, The motion condition determination module includes: The first motion condition determination submodule is used to determine, from the preset number of frames corresponding to the detected target at the current time, the number of target frames whose absolute velocity to the ground is greater than a preset threshold for the target; determine whether the number of target frames is greater than a second preset threshold for the number of target frames; and determine that the detected target meets the preset motion conditions if the number of target frames is greater than the second preset threshold for the number of target frames. The second motion condition determination submodule is used to multiply the absolute velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the ground motion distance corresponding to the detected target; if the sum of the ground motion distances corresponding to the preset number of frames is greater than the preset ground distance threshold of the target, it is determined that the detected target meets the preset motion conditions; and / or, The absolute velocity relative to the ground includes the lateral absolute velocity relative to the ground and the longitudinal absolute velocity relative to the ground, and the distance of motion relative to the ground includes the lateral distance of motion relative to the ground and the longitudinal distance of motion relative to the ground. The first motion condition determination submodule includes: The first frame number determination unit is used to determine the first frame number corresponding to the ground lateral absolute velocity being greater than a preset ground lateral absolute velocity threshold from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time. The first lateral motion condition determination unit is used to determine that the detected target meets the first lateral motion condition when the first frame number is greater than the first frame number threshold. The second frame number determination unit is used to determine the number of second frames from the preset number of frames corresponding to the detected target detected by the millimeter-wave radar that are closest to the current time, where the corresponding longitudinal absolute velocity to the ground is greater than a preset threshold. The first longitudinal motion condition determination unit is used to determine that the detected target meets the first longitudinal motion condition when the second frame number is greater than the second frame number threshold. The second motion condition determination submodule includes: The lateral motion distance determination unit is used to multiply the absolute lateral velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the lateral motion distance to the ground corresponding to the detected target. The second lateral motion condition determination unit is used to determine that the detected target meets the second lateral motion condition when the sum of the ground lateral motion distances corresponding to the preset number of frames is greater than the first distance threshold. The longitudinal motion distance determination unit is used to multiply the absolute longitudinal velocity to the ground by the time interval detected by the millimeter-wave radar to obtain the longitudinal motion distance to the ground corresponding to the detected target. The second longitudinal motion condition determination unit is configured to determine that the detected target meets the second longitudinal motion condition when the sum of the longitudinal motion distances to the ground corresponding to the preset number of frames is greater than a second distance threshold; and / or, The tangential motion determination module includes: The longitudinal motion determination submodule is used to determine that the inspected target has undergone longitudinal motion when the inspected target meets the first longitudinal motion condition and the second longitudinal motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition. The lateral motion determination submodule is used to determine that the inspected target has undergone lateral motion when the inspected target meets the first lateral motion condition and the second lateral motion condition, and the polarity of the measured ground Doppler meets the preset polarity condition. A tangential motion determination submodule is used to determine that the inspected target has undergone tangential motion when the inspected target undergoes longitudinal and / or lateral motion; and / or, The measurement speed includes lateral measurement speed and longitudinal measurement speed; The absolute velocity determination module includes: The stationary target longitudinal velocity determination submodule is used to take the difference between the linear velocity of the millimeter-wave radar and the longitudinal linear velocity as the stationary target longitudinal velocity, wherein the longitudinal linear velocity is the product of the yaw rate of the millimeter-wave radar and the lateral distance corresponding to the detected target; The stationary target lateral velocity determination submodule is used to take the product of the yaw rate and the longitudinal distance corresponding to the detected target as the stationary target lateral velocity. The longitudinal absolute velocity determination submodule is used to calculate the difference between the longitudinal measured velocity and the longitudinal velocity of the stationary target to obtain the longitudinal absolute velocity of the detected target relative to the ground. The lateral absolute velocity determination submodule is used to calculate the difference between the measured lateral velocity and the lateral velocity of the stationary target, thereby obtaining the ground-based lateral absolute velocity corresponding to the detected target; and / or, The device further includes: A velocity measurement fitting module is used to obtain the measured velocity of the detected target by linear fitting based on the target distance corresponding to the most recently detected preset number of frames and the time interval of the millimeter-wave radar detection; and / or, The device further includes: The stationary point cloud clustering module is used to cluster the stationary point cloud based on the target distance corresponding to the stationary point cloud when the point cloud detected by the millimeter-wave radar is a stationary point cloud, and obtain the clustering result. The clustering result matching module is used to match the clustering result with the clustering result corresponding to the previous frame; The target clustering determination module is used to add the current frame to the target cluster to which the previous frame belongs when a match is successful, wherein the target cluster stores a preset number of frame data; The absolute velocity determination module includes: An absolute velocity determination submodule is used to determine the ground absolute velocity of the detected target based on the measured velocity of the detected target and the velocity of stationary targets corresponding to a preset number of frames included in the target cluster; and / or, The device further includes: The parameter calculation module is used to calculate the average measurement distance and the standard deviation of the measurement distance based on the measurement distance of the stationary point cloud detected by the millimeter-wave radar corresponding to the preset number of frames included in the target cluster, and to traverse each stationary point cloud. The point cloud traversal module is used to determine the relationship between the absolute value and the product of the current stationary point cloud being traversed. The absolute value is the absolute value of the difference between the measured distance and the average value of the measured distance, and the product is the product between the standard deviation of the measured distance and a preset ratio. The counting module is used to include the measurement distance corresponding to the stationary point cloud into the effective measurement distance sum value when the absolute value is less than the product, and to increment the number of effective point clouds by 1; The termination condition determination module is used to determine whether all static point clouds have been traversed if the absolute value is not less than the product. The return module is used to traverse the next static point cloud before all static point clouds have been traversed, and to trigger the point cloud traversal module. The target distance determination module is used to calculate the quotient between the effective measured distance and the number of effective point clouds after traversing all stationary point clouds, and obtain the target distance.

13. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor, when executing a program stored in memory, implements the method described in any one of claims 1-10.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1-10.

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