A radar-based target measurement method, integrated circuit, sensor, and device

Abstract

This application relates to the field of radar technology, and discloses a radar-based target measurement method, integrated circuit, sensor, and device. The radar-based target measurement method includes: acquiring a radar echo signal; measuring a target based on the radar echo signal to obtain a first measurement value; determining a reference signal transmission model from a preset signal transmission model based on the first measurement value, wherein each signal transmission model corresponds to a type of signal transmission path; and calculating a second measurement value based on the signal transmission model and the radar echo signal. This method is at least beneficial for more accurate and effective target measurement.

Description

Technical Field

[0001] This application relates to the field of radar technology, and in particular to a radar-based target measurement method, integrated circuit, sensor, and device. Background Technology

[0002] Radar (radio detection and ranging) technology refers to the technology of using electromagnetic waves to detect targets and determine their relevant parameters. Its working principle is as follows: radar transmits signals, i.e., electromagnetic waves. When these electromagnetic waves encounter a target, they are reflected to generate radar echo signals. By receiving and processing these radar echo signals, it is possible to determine whether a target exists, and to obtain information such as the target's distance relative to the electromagnetic wave emission point, its rate of change of distance (radial velocity), azimuth, and altitude, thus achieving target measurement.

[0003] However, the accuracy of existing radar-based target measurement schemes is not high, which affects the effectiveness of subsequent operations and decision-making. Summary of the Invention

[0004] This application provides a radar-based target measurement method, integrated circuit, sensor, and device, which at least facilitates more accurate and effective target measurement.

[0005] According to some embodiments of this application, a first aspect of this application provides a radar-based target measurement method, comprising: acquiring a radar echo signal; measuring a target based on the radar echo signal to obtain a first measurement value; determining a reference signal transmission model from a preset signal transmission model based on the first measurement value, wherein each signal transmission model corresponds to a type of signal transmission path; and calculating a second measurement value based on the signal transmission model and the radar echo signal.

[0006] According to some embodiments of this application, a second aspect of this application also provides an integrated circuit, including a radio frequency (RF) module, an analog signal processing module, and a digital signal processing module connected in sequence; wherein, the RF module is used to generate RF transmission signals and receive RF reception signals; the analog signal processing module is used to down-convert the RF reception signals to obtain intermediate frequency (IF) signals; the digital signal processing module is used to perform analog-to-digital conversion on the IF signals, and to process the digital data obtained from the analog-to-digital conversion using a radar-based target measurement method as described in any embodiment of this application, so as to achieve target measurement.

[0007] According to some embodiments of this application, a third aspect of this application also provides an electromagnetic wave sensor, including: a carrier; an integrated circuit as described in any embodiment of this application, disposed on the carrier; an antenna, disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device disposed on the carrier; wherein the integrated circuit is connected to the antenna and is used to transmit radio frequency transmission signals and / or receive radio frequency reception signals.

[0008] According to some embodiments of this application, a fourth aspect of this application also provides a terminal device, including: a device body; and an electromagnetic wave sensor disposed on the device body as described in any embodiment of this application; wherein the electromagnetic wave sensor is used for target detection, target measurement and / or communication to provide reference information to the operation of the device body.

[0009] The technical solution provided in this application has at least the following advantages:

[0010] During target measurement, after obtaining the first measurement value based on the acquired radar echo signal, a reference signal transmission model is selected from the preset signal transmission models corresponding to various signal transmission paths based on the first measurement value. This allows for an accurate description of the actual signal transmission process. Thus, the second measurement value calculated based on the reference signal transmission model and the radar echo signal will be more accurate and effective than the first measurement value. Attached Figure Description

[0011] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0012] Figure 1 This is a flowchart of the radar-based target measurement method provided in the embodiments of this application;

[0013] Figure 2 This is a simplified schematic diagram of an application scenario involving the radar-based target measurement method provided in the embodiments of this application;

[0014] Figure 3 This is a simplified schematic diagram illustrating another application scenario involving the radar-based target measurement method provided in the embodiments of this application;

[0015] Figure 4 This is a simplified schematic diagram of the antenna array involved in the radar-based target measurement method provided in the embodiments of this application;

[0016] Figure 5This is a schematic diagram of the reflector surface estimation involved in the radar-based target measurement method provided in the embodiments of this application;

[0017] Figure 6 This is an output diagram of the experimental results of the radar-based target measurement method provided in the embodiments of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been presented in the various embodiments of this application to enable readers to better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0019] The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0020] The first aspect of this application provides a radar-based target measurement method applied to radar. The radar can be any device, equipment, or system with electromagnetic wave transmission and reception capabilities, as well as computational functions, such as a radar sensor or a vehicle-mounted system. The radar-based target measurement method provided in this application can find the most suitable and accurate signal transmission model describing the current signal transmission path from a preset signal transmission model using the less accurate initial measurement values. This reference signal transmission model is then used to update the initial measurement values, making the measurement results more accurate, effective, and reliable. For ease of understanding, the radar-based target measurement method provided in this application will be described below.

[0021] In some embodiments, such as Figure 1 As shown, the flow of the radar-based target measurement method includes at least the following steps:

[0022] Step 101: Acquire radar echo signal.

[0023] Step 102: Measure the target based on the radar echo signal to obtain the first measurement value.

[0024] Step 103: Based on the first measurement value, determine one of the preset signal transmission models as a reference signal transmission model, wherein each signal transmission model corresponds to a type of signal transmission path.

[0025] Step 104: Calculate the second measurement value based on the reference signal transmission model and the radar echo signal.

[0026] In this way, during the target measurement process, after obtaining the first measurement value by measuring the target based on the acquired radar echo signal, a reference signal transmission model is selected from the preset signal transmission models corresponding to various signal transmission paths based on the first measurement value. Thus, an accurate description of the actual signal transmission process can be obtained through the reference signal transmission model. In this way, the second measurement value calculated based on the reference signal transmission model and the radar echo signal will be more accurate and effective than the first measurement value.

[0027] In addition, by Figure 1 As can be seen, the implementation process of the method is simple, and since the signal transmission model is pre-defined, there is no need to spend extra time modeling the actual signal transmission process. In other words, the target measurement implemented based on this method will not significantly increase the target measurement latency. That is, it can improve the accuracy and effectiveness of the measurement results without significantly affecting the real-time performance of the target measurement.

[0028] For ease of understanding Figure 1 The steps of the illustrated embodiment will be explained below.

[0029] In step 101, radar echo signals are acquired. Radar echo signals refer to signals received through a receiving antenna. This embodiment does not limit the scope of radar echo signals; they may include echo signals generated by electromagnetic waves radiated outward through a transmitting antenna and reflected by a target, and may also include noise.

[0030] In step 102, the target is measured based on the radar echo signal to obtain a first measurement value. This embodiment of the application does not limit the first measurement value, nor the specific process of how the target is measured to obtain the first measurement value.

[0031] Regarding the first measurement value, it is understandable that the measurement requirements for the target may differ based on different user needs and application scenarios. That is, the data content of the first measurement value may not be entirely the same. For example, the first measurement value may include at least one of the following parameters: altitude, pitch angle, azimuth angle, lateral distance, and longitudinal distance. Of course, the above is just an example; other data may also be included, which will not be listed here.

[0032] Regarding how to perform target measurement to obtain the first measurement value, it is understandable that, as mentioned earlier, the first measurement value may have multiple possibilities. Correspondingly, the processing required for measuring different data will also vary. It is also understandable that, based on different user needs and application scenarios, the electromagnetic waves radiated outward may have different forms; for example, electromagnetic waves may be microwaves, ultrasound, or millimeter waves. Accordingly, when performing target detection and measurement based on different forms of electromagnetic waves, even when measuring the same target data, different processing methods are usually required based on different signal characteristics. Therefore, different schemes can be adaptively adopted to achieve target measurement based on different electromagnetic wave forms and different first measurement values. The relevant target measurement implementation schemes have been described in related technologies and will not be elaborated upon here.

[0033] It is understood that since the embodiments of this application further process to obtain a more accurate and effective second measurement value, the first measurement value, as an initial measurement result, is not the final result. Its accuracy, reliability, and other requirements can be appropriately lowered. In particular, a simple and computationally efficient scheme can be used to measure the target to obtain the first measurement value, thereby improving the efficiency of the complete target measurement provided in the embodiments of this application and further improving real-time performance to support applications with real-time requirements, such as obstacle avoidance.

[0034] Based on this, in some embodiments, the first measurement value is obtained by measuring the target based on the radar echo signal, which can be achieved as follows: the first measurement value is obtained by measuring the target based on the radar echo signal in a scenario without multipath interference.

[0035] In this way, by assuming that the signal transmission process corresponding to the radar echo signal is free from multipath interference, the complexity of the radar echo signal is reduced, thereby simplifying the target measurement processing based on this, reducing the amount of calculation and increasing efficiency, thus improving the overall efficiency of target measurement.

[0036] Of course, the above is only an example of performing target measurement to obtain the first measurement value. In some embodiments, other methods can be used to achieve this, which will not be listed here.

[0037] In step 103, based on the first measurement value, a reference signal transmission model is determined from a set of preset signal transmission models, wherein each signal transmission model corresponds to a type of signal transmission path. This embodiment of the application does not limit the preset signal transmission models. Furthermore, this embodiment of the application does not limit the specific implementation method of how the reference signal transmission model is determined based on the first measurement value.

[0038] For a pre-defined signal transmission model, it's understandable that in the actual scenario where the target is located, there may be objects such as the ground and other targets around the target. These objects provide reflective surfaces for the electromagnetic waves radiated outward from the transmitting antenna and the echo signals generated by reflection. This means that the signal transmission path is not limited to radar-target-radar (i.e., the electromagnetic waves radiated outward from the transmitting antenna are directly transmitted to the target through a medium, reflected at the target surface to generate an echo signal, and the echo signal is directly transmitted to the receiving antenna through the medium). Instead, a reflection transmission path based on the reflective surface may form. Furthermore, multipath propagation may also exist. In other words, there are multiple possibilities for the signal transmission path. Consequently, the signal transmission model formed based on the signal transmission path will have multiple possibilities.

[0039] It should be noted that the embodiments of this application do not limit the number of preset signal transmission models or the specific corresponding signal transmission paths, which can be determined based on the frequency of occurrence of the scenario, user needs, hardware capabilities, etc. For ease of understanding, the following will provide examples of signal transmission models; however, this does not mean that the preset signal transmission models must be as shown in the examples below.

[0040] In some embodiments, the signal transmission model includes at least one model formed based on a single signal transmission path, and / or at least one multipath model, wherein each multipath model is a model formed based on at least two different single signal transmission paths.

[0041] In this way, by using the multipath model, target measurement can accurately measure targets in the presence of multipath, overcome the adverse effects of multipath, and achieve more accurate target measurement.

[0042] In some cases, the single signal transmission paths corresponding to different multipath models are not exactly the same, and / or, the model weights of the same single signal transmission path corresponding to different multipath models are different.

[0043] It should be noted that the above are merely examples of multipath models. It is understood that, to reduce the number of models, in some embodiments, the different multipath models described above can be combined into a single signal transmission model. This model comprises a predetermined number of models formed based on a single signal transmission path, each with a corresponding weight. This weight characterizes the proportion of the signal transmitted by that single signal transmission path in the multipath model. The types of signal transmission models will not be listed here.

[0044] In some examples, a single signal transmission path includes at least one of the following paths: radar-target-radar, radar-target-reflector-radar, radar-reflector-target-radar, or radar-reflector-target-reflector-radar.

[0045] To facilitate understanding of the paths described above, the following will combine... Figure 2 and Figure 3 The following are simplified scene modeling diagrams, each including radar and targets, for illustration. Figure 2 and Figure 3 Both assume that the reflector is provided by the ground. Figure 2 The ground in the middle has no slope. Figure 3 The ground in the middle is uneven and has a slope.

[0046] exist Figure 2 In the scenario shown, point O is the location of the radar antenna (or the location of the radar). In the presence of a reflective surface, ground point P represents the reflective surface, point A is the point of incidence when reflection occurs on the reflective surface, and point B is the location of the target. The radar-target-radar path is the path from point O directly to point B and then back to point O (direct-to-direct); the radar-target-reflective surface-radar path is the path from point O directly to point B and then back to point O via point A (direct-indirect); the radar-reflective surface-target-radar path is the path from point O via point A to point B and then back to point O via point B (indirect-to-direct); and the radar-reflective surface-target-reflective surface-radar path is the path from point O via point A to point B and then back to point O via point A (indirect-indirect).

[0047] exist Figure 3 In the scenario shown, point O is the location of the radar antenna. In the presence of a reflective surface, the tangent P at a point on the ground represents the reflective surface. Point A is the point of incidence when reflection occurs on the reflective surface, and point B is the location of the target. In this case, the radar-target-radar path is the path from point O directly to point B and then back to point O; the radar-target-reflective surface-radar path is the path from point O directly to point B and then back to point O via point A; the radar-reflective surface-target-radar path is the path from point O via point A to point B and then back to point O; and the radar-reflective surface-target-reflective surface-radar path is the path from point O via point A to point B and then back to point O via point A.

[0048] It should be noted that the above are merely examples. It is understood that the examples above involve only one reflecting surface. In this case, the path complexity is low, and consequently, the complexity of the corresponding signal transmission model is also low. The calculations related to the signal transmission model are also relatively simple. Therefore, the computational load related to the signal transmission model is small, and the efficiency is high, which can further improve the real-time performance of radar-based target measurement methods implemented based on these signal transmission models. Of course, in some embodiments, a single signal transmission path can involve two or more reflecting surfaces, and the scene modeling diagram is similar to... Figure 2 Similarly, I won't go into detail here.

[0049] Regarding how to determine the reference signal transmission model based on the first measurement value, it is understood that the first measurement is a value that approximates the actual target data. Therefore, the first measurement value can be used as the actual target data and combined with various signal transmission models to obtain the electromagnetic wave signal transmission process described by each model. This allows us to find the electromagnetic wave signal transmission process that best matches the actual electromagnetic wave characteristics and / or the actual electromagnetic wave transmission characteristics, thus finding the corresponding reference signal transmission model. Therefore, determining the reference signal transmission model based on the first measurement value can be achieved using any scheme implemented through the above concept. To facilitate a better understanding of the above concept by those skilled in the art, examples will be provided below.

[0050] In some embodiments, determining a reference signal transmission model from a preset signal transmission model based on a first measurement value can be achieved as follows: determining the effective signal components of the radar echo signal under each signal transmission model based on the first measurement value; and determining the reference signal transmission model based on the effective signal components of the radar echo signal under each signal transmission model.

[0051] In this way, by combining the real characteristics of the effective signal components in the signal, a reference signal transmission model that is more in line with the actual situation can be determined.

[0052] It is also understandable that a signal typically consists mainly of effective signal components mixed with some noise. Based on this, in some embodiments, the effective signal components of the radar echo signal under each signal transmission model are determined according to the first measurement value, using the following expression:

[0053]

[0054] Where, x i ' represents the effective signal component of the radar echo signal under the i-th signal transmission model and when the target has a first measurement value relative to the radar. Representing matrix A i The conjugate transpose of the matrix. xi Let i be the modeling representation of the radar echo signal under the i-th signal transmission model. A ti Let A be the radar transmitting antenna steering vector under the i-th signal transmission model determined based on the first measurement value. ri Let ρ be the radar receiving antenna steering vector under the i-th signal transmission model determined based on the first measurement value. i Let n be the amplitude representation of the effective signal under the i-th signal transmission model. i Let be the noise representation under the i-th signal transmission model, where max y1 represents the operation of finding the maximum value of function y1, and ||y2|| represents the operation of finding the magnitude of vector y2. This represents the Kronecker product operation.

[0055] It is also understandable that, as mentioned earlier, the first measurement value may be one of altitude, elevation angle, azimuth angle, lateral distance, or longitudinal distance. Altitude, elevation angle, and longitudinal distance are interconnected, as are azimuth angle, lateral distance, and longitudinal distance. Furthermore, altitude and elevation angle, compared to azimuth angle and lateral distance, focus on different target dimensions. The dimensions of altitude and elevation angle can be considered as projecting the scene of the target and radar from three-dimensional space to two-dimensional space, ignoring the azimuth dimension. Similarly, the dimensions of azimuth angle and longitudinal distance can be considered as projecting the scene of the target and radar from three-dimensional space to two-dimensional space, ignoring the elevation dimension. This further simplifies the signal transmission model, thereby reducing its complexity, decreasing the computational workload, and ultimately improving target measurement efficiency.

[0056] As mentioned above, since the dimensions of altitude and elevation angle can be considered as projecting the scene of the target and radar from three-dimensional space to two-dimensional space after ignoring the azimuth dimension, and the dimensions of azimuth angle and longitudinal distance can be considered as projecting the scene of the target and radar from three-dimensional space to two-dimensional space after ignoring the elevation dimension, the measurement of altitude and elevation angle is roughly similar to the measurement of azimuth angle and longitudinal distance. For ease of understanding, the following explanation uses the measurement of altitude and / or elevation angle (i.e., the case where the first measurement includes altitude and / or elevation angle) as an example. This allows for accurate decision-making regarding whether a vehicle equipped with onboard radar can pass through scenarios such as height restriction poles, overpasses, tunnels, and surface obstacles through the estimation of altitude and / or elevation angle, thereby supporting crucial performance aspects such as automotive 4D imaging radar.

[0057] To facilitate a better understanding of the above embodiments by those skilled in the art, specific examples will be provided. Figure 4 Taking the Multiple-Input Multiple-Output (MIMO) antenna shown as an example, combined with Figure 2 and Figure 3The simplified scenario diagrams provided are used for explanation.

[0058] like Figure 4 As shown, the radar antenna includes M transmitting antennas (i.e., Figure 4 The left side shows T1, T2, T3, ..., TM) and N receiving antennas (i.e. Figure 4 The distances of these M transmitting antennas (R1, R2, R3, ..., RM) relative to the transmitting reference plane are d in sequence. T1 d T2 d T3 ... d TM The distances of these N receiving antennas relative to the receiving reference plane are d, respectively. R1 d R2 d R3 ... d RN Therefore, based on Figure 4 The antenna array shown below, under the i-th signal transmission model, will have the following radar transmitting antenna steering vector A. ti and radar receiving antenna steering vector A ri :

[0059]

[0060] in, Let be the radiation direction of the transmitting antenna in the i-th signal transmission model. Let λ represent the signal receiving direction of the receiving antenna in the i-th signal transmission model, and λ be the wavelength of the radiated electromagnetic wave.

[0061] That is, given a fixed antenna array, the steering vector of the radar transmitting antenna is determined based on the radiation direction of the transmitting antenna, and the steering vector of the radar receiving antenna is determined based on the signal receiving direction of the receiving antenna.

[0062] And in Figure 2 and Figure 3 In the scenario shown, specifically, the angle formed by line segment OB and the horizontal plane (i.e., the target's elevation angle relative to the radar) is: The angle formed by line segment OA and the horizontal plane (i.e., the elevation angle of the signal's incident point on the reflecting surface relative to the radar) is: Figure 3 The calculation also involves the angle α between the reflecting surface P and the horizontal plane. At this point, it is easy to see that:

[0063] In the radar-target-radar signal transmission path

[0064] In the signal transmission path from radar to target to reflector and back to radar

[0065] In the signal transmission path of radar-reflector-target-radar

[0066] In the signal transmission path of radar-reflector-target-reflector-radar

[0067] Based on this, in some embodiments, the determination of the radar transmitting antenna steering vector and the radar receiving antenna steering vector satisfies the following:

[0068] In the signal transmission model, the radar transmitting antenna steering vector and radar receiving antenna vector corresponding to the radar-target-radar signal transmission path are both obtained based on the target's elevation angle relative to the radar, which is determined by the first measurement value.

[0069] And / or,

[0070] In the signal transmission model, the radar transmitting antenna steering vector corresponding to the signal transmission path of radar-target-reflector-radar is obtained based on the elevation angle of the target relative to the radar determined by the first measurement value, and the radar receiving antenna steering vector is obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar determined by the first measurement value.

[0071] And / or,

[0072] In the signal transmission model, the radar transmitting antenna steering vector corresponding to the signal transmission path of radar-reflector-target-radar is obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar, which is determined by the first measurement value; and the radar receiving antenna steering vector is obtained based on the elevation angle of the target relative to the radar, which is determined by the first measurement value.

[0073] And / or,

[0074] In the signal transmission model, the radar transmitting antenna steering vector and radar receiving antenna steering vector corresponding to the signal transmission path of radar-reflector-target-reflector-radar are both obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar, which is determined by the first measurement value.

[0075] In this way, by determining the corresponding radar transmitting antenna steering vector and radar receiving antenna vector through the relevant angles described above, the height and / or elevation angle in the first measurement value can be directly associated with the radar transmitting antenna steering vector and radar receiving antenna vector. Thus, the first measurement value can be directly used to determine the effective signal component without needing to go through many intermediate conversions, resulting in lower complexity and higher efficiency.

[0076] In some embodiments, the angle of incidence of the signal on the reflecting surface relative to the radar, determined by the first measurement value. Determined by the following expression:

[0077]

[0078] in, Let α be the elevation angle of the target relative to the radar, determined by the first measurement, and let α be the angle formed by the reflecting surface and the horizontal plane.

[0079] In this way, the elevation angle of the signal incident point on the reflecting surface relative to the radar is expressed as a concise expression of the elevation angle of the target relative to the radar. This makes it possible to handle only the elevation angle of the target relative to the radar as an unknown among the two angles mentioned above, which simplifies the calculation, reduces the amount of computation, and improves the measurement efficiency.

[0080] The specific analysis process is as follows:

[0081] refer to Figure 2 and Figure 3 The scene shown, in, L is the longitudinal distance from the target to the radar, H1 is the radar's altitude relative to the ground, and H2 is the target's altitude relative to the ground.

[0082] Considering that in automotive radar, the elevation angle is usually small, often less than 15° (i.e., x≈sinx); and that the target is at a great distance, the elevation angle of a real object is usually even smaller, therefore the above formula can be simplified to:

[0083]

[0084] Understandably, when the distance between the multipath and the direct wave is less than one range-resolved cell, the presence of multipath will affect the estimation of the elevation angle of the direct wave (target's elevation angle). and

[0085] in, L is the longitudinal distance from the target to the radar, H1 is the radar's altitude relative to the ground, and H2 is the target's altitude relative to the ground.

[0086] That is, in satisfying and / or Signals transmitted via other signal transmission paths will be identified in the same range resolution cell as signals transmitted via radar-target-radar transmission paths (i.e., direct waves are subject to multipath interference).

[0087] In other words, multipath interference direct waves only occur at relatively long distances, where H1 is much smaller than R1. Since the value is close to 0, it can be ignored, meaning the above formula can be simplified to:

[0088]

[0089] When the reflecting surface is the ground and the ground has no slope, α = 0; when the reflecting surface is the ground and the ground has a slope, α ≠ 0.

[0090] Furthermore, based on real-world scenarios, it's easy to see that in situations like vehicle-mounted radar, the target exists above the reflective surface, i.e.

[0091] From the above analysis, it is easy to see that after obtaining the first measurement value (taking height as an example), The effective signal component can be further calculated using information such as the longitudinal distance of the target relative to the radar and the altitude of the radar relative to the ground. In other words, when determining the effective signal component according to the above-mentioned embodiments or combinations thereof, the expression for obtaining the effective signal component has only one unknown variable to be determined, namely α (it is understood that in reality, the reflecting surface is constantly changing, therefore α is uncertain). That is, determining the effective signal component is essentially transformed into finding the most suitable α.

[0092] Regarding the search for α, in some embodiments, iterative steps can be taken starting from a preset value, and the most suitable α can be determined through relevant optimization algorithms. However, this application does not limit the specific value of the preset value.

[0093] In some embodiments, as can be understood from the meaning of α, it is also equivalent to identifying a reflecting surface, which is typically also detected as a target. Therefore, the reflecting surface in the multipath scenario where the target is detected during the first measurement can be located, and α can be determined based on the found reflecting surface. Multiple implementations of estimating reflecting surfaces in multipath scenarios have been described in related technologies, and will not be elaborated upon here.

[0094] It is also understandable that obtaining the reflection surface of the target detected during the process of finding its possible multipath scenarios through the first measurement is only a preliminary estimate of the reflection surface. Therefore, the initial value α0 of α can be determined based on the preliminary estimate of the reflection surface, and the optimal value α can be obtained by iterative optimization starting from α0.

[0095] In other words, in some embodiments, the angle formed by the reflective surface and the horizontal plane is determined through iterative optimization as an unknown quantity. The initial value for iterating the angle formed by the reflective surface and the horizontal plane is a preset value. Alternatively, the initial value for iterating the angle formed by the reflective surface and the horizontal plane is obtained by multipath reflection surface estimation based on the positions of several target points, wherein the positions of the target points are obtained based on radar echo signals.

[0096] To help those skilled in the art better understand how multipath reflector estimation is implemented, examples will be provided below. However, this does not mean that multipath reflector estimation can only and must be implemented through the following examples.

[0097] In some embodiments, when the first measurement includes height, the position of the target point is represented by the target's height and its longitudinal depth relative to the radar. In this case, the angle between the reflecting surface and the horizontal plane can be determined by: converting the target point's position into a coordinate system with the target's height as the vertical axis and the longitudinal depth relative to the radar as the horizontal axis; fitting the converted coordinate point to the fitted curve as the reflecting surface to determine the angle between the reflecting surface and the horizontal plane. This application does not limit the algorithm used to fit the converted coordinate point; algorithms such as least squares fitting, higher-order polynomial fitting, etc., are all acceptable.

[0098] For example, refer to Figure 5 The diagram shown is a schematic of the target point cloud output by the radar, in which, Figure 5 The vertical axis of the point cloud diagram shows the target's height (in meters), and the horizontal axis shows the target's longitudinal distance (represented by "Y" in meters) relative to the radar. The reflector surface, represented by the red line in the diagram, can then be obtained using the least squares method.

[0099] Of course, the above embodiments and Figure 5 For illustrative purposes only, other multipath reflector estimation methods or other fitting methods may be used in some embodiments, which will not be elaborated here.

[0100] In some embodiments, the reference signal transmission model is determined based on the effective signal components corresponding to the radar echo signal under each signal transmission model. This can be achieved by: determining the maximum effective signal component of the radar echo signal from the effective signal components corresponding to the radar echo signal under each signal transmission model; and using the signal transmission model corresponding to the maximum effective signal component of the radar echo signal as the reference signal transmission model.

[0101] In this way, the reference signal transmission model can be determined efficiently, accurately, and quickly through maximum likelihood estimation, which is beneficial to further improving the accuracy, effectiveness, and efficiency of target measurement.

[0102] To facilitate understanding of the above embodiments, different examples will be used to illustrate them below. However, this does not mean that they can only be implemented through the following examples.

[0103] In some cases, the maximum effective signal component of the radar echo signal can be determined from the effective signal components corresponding to each signal transmission model as follows: Based on the effective signal components corresponding to each signal transmission model, determine the matching parameters corresponding to each signal transmission model, and use the matching parameters as a representation of the relative magnitude of the effective signal components corresponding to the corresponding signal transmission model.

[0104] In some embodiments, the matching parameter is determined by at least one of the following expressions:

[0105]

[0106] η2 i =‖x i ||-||x i ′‖;

[0107] Where, η1 i η2 i x represents different representations of the matching parameters or different elements in the matching parameters under the i-th signal transmission model. i Let ' be the effective signal component under the i-th signal transmission model, and x be the effective signal component. i Let y2 be the modeling representation of the radar echo signal under the i-th signal transmission model, and let y2 be the operation of finding the modulus of vector y2.

[0108] Of course, the above is merely an example illustrating how to determine the reference signal transmission model based on the first measurement value. In some embodiments, the reference signal transmission model can be determined based on the effective signal components corresponding to the radar echo signal under each signal transmission model. This can also be achieved by determining the reference transmission model based on the effective signal components corresponding to the radar echo signal under each signal transmission model and the trained network model. In other words, it can also be implemented using a network model, and its implementation methods will not be listed here.

[0109] It should be noted that the above examples mainly analyze and process the characteristics of the effective signal components and noise components in the signal to determine the reference signal model. In some embodiments, other methods can also be used, which will not be elaborated here.

[0110] Step 104: Calculate the second measurement value based on the reference signal transmission model and the radar echo signal. It can be understood that at this point, the radar echo signal can be considered as the electromagnetic wave radiated by the radar through the transmitting antenna passing through the signal transmission process described by the reference signal transmission model to obtain the radar echo signal. Therefore, by processing and calculating the reference signal transmission model and the radar echo signal, the second measurement value of the target in the reference signal transmission model can be determined.

[0111] It should be noted that the second measurement value is similar to the first measurement value mentioned above, and may include at least one of the following parameters: altitude, pitch angle, azimuth angle, lateral distance, and longitudinal distance. However, it should be noted that the first and second measurements do not need to be exactly the same. For example, the first measurement value may only include altitude, while the second measurement value may include parameters such as altitude and pitch angle.

[0112] It should also be noted that the required processing and calculations will vary depending on the model construction method and the second measurement value, which will not be elaborated here.

[0113] To help those skilled in the art better understand the above embodiments, the following will provide illustrative examples.

[0114] First, refer to Figure 2 and Figure 3 The scenario shown is assumed to be... Figure 4 The antenna array shown is modeled using the following expression as a preset signal transmission model. Specifically:

[0115] For signal transmission model 1, which only corresponds to the radar-target-radar signal transmission path:

[0116] Signal modeling as

[0117] in,

[0118] Target pitch angle Modeling as

[0119] in,

[0120] Matching parameters of the corresponding signal transmission model 1

[0121] For signal transmission model 2, which only corresponds to the signal transmission path of radar-target-reflector-radar:

[0122] Signal modeling as

[0123] in,

[0124] Target pitch angle Modeling as

[0125] in,

[0126] Matching parameters of the corresponding signal transmission model 2

[0127] For signal transmission model 3, which only corresponds to the signal transmission path of radar-reflector-target-radar:

[0128] Signal modeling as

[0129] in,

[0130] Target pitch angle Modeling as

[0131] in,

[0132] Matching parameters of the corresponding signal transmission model 3

[0133] For signal transmission model 4, which only corresponds to the signal transmission path of radar-reflector-target-reflector-radar:

[0134] Signal modeling as

[0135] in,

[0136] Target pitch angle Modeling as

[0137] in,

[0138] Matching parameters of the corresponding signal transmission model 4

[0139] For the signal transmission model 5 corresponding to the multipath formed by the above path combination:

[0140] Signal modeling as

[0141] Among them, A t1 A r1 A t2 A r2 A t3 A r3 A t4 A r4 As previously explained, it will not be repeated here. w1, w2, w3, and w4 are the model weights for the corresponding paths.

[0142] Target pitch angle Modeling as

[0143] in,

[0144] Matching parameters of the corresponding signal transmission model 5

[0145] in,

[0146] Secondly, the five signal transmission models provided above are stored as known information and then invoked during the application of the radar-based target measurement method provided in the above embodiments. Specifically:

[0147] 1. Obtain radar echo signals by transmitting and receiving signals.

[0148] 2. Based on the radar echo signal, digital beamforming (DBF) of the elevation angle is performed under the assumption that there is no multipath, and the original altitude value is obtained as the first measurement value.

[0149] 3. The point cloud maps of the numerous targets identified through the DBF processing described above (the output format of the point cloud maps is as follows) Figure 5 As shown, the reflector surface is estimated based on the least squares fitting algorithm, and the initial α0 is further determined.

[0150] 4. Based on α0 and the first measured value, call the above 5 signal transmission models, and optimize iteratively starting from α0 with (α0-Δα, α0+Δα) as the search range, to find the most suitable α and determine the corresponding values ​​for each of the above 5 signal transmission models. Matching parameters.

[0151] 5. The signal transmission model with the largest matching parameter value is used as the reference signal transmission model, and the target height is recalculated based on the radar echo signal and the reference signal transmission model as the second measurement value.

[0152] It should be noted that the above examples mainly use height measurement scenarios for illustration.

[0153] Based on the comparative experiments provided in the above examples, the following results can be obtained: Figure 6 The results are shown. Among them, Figure 6 The output of the first measurement is shown above. Figure 6 The output of the second measurement is shown below. Comparing the two figures, it's clear that the output of the second measurement is less volatile, more stable, and more accurate and effective. Figure 6The vertical axis represents the first measurement (Raw Height measurement, denoted by "Height", in meters) / the second measurement (Real Height measurement, denoted by "Height", in meters), and the horizontal axis represents the longitudinal distance of the target (denoted by "Y", in meters).

[0154] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0155] The second aspect of this application relates to an integrated circuit, comprising a radio frequency (RF) module, an analog signal processing module, and a digital signal processing module connected in sequence; wherein the RF module is used to generate RF transmit signals and receive RF receive signals; the analog signal processing module is used to down-convert the RF receive signals to obtain intermediate frequency (IF) signals; and the digital signal processing module is used to perform analog-to-digital conversion on the IF signals, and to process the digital data obtained from the analog-to-digital conversion using a radar-based target measurement method as described in any embodiment of this application, so as to achieve target measurement.

[0156] In some embodiments, the integrated circuit may further include a data processing module for processing digital signals to achieve target detection and / or wireless communication.

[0157] In some embodiments, the integrated circuit may be a millimeter-wave chip.

[0158] In some embodiments, the radio frequency received signal is the echo signal formed by the radio frequency transmitted signal being emitted and / or scattered by the target, and the integrated circuit is a sensor chip.

[0159] In some embodiments, the integrated circuit may be a millimeter-wave chip.

[0160] In some embodiments, the radio frequency received signal is the echo signal formed by the radio frequency transmitted signal being emitted and / or scattered by the target, and the integrated circuit is a sensor chip.

[0161] It is not difficult to see that the above embodiments are circuit embodiments corresponding to the method embodiments, and the above embodiments can be implemented in conjunction with the method embodiments. The relevant technical details mentioned in the method embodiments are still valid in the above embodiments, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in the above embodiments can also be applied to the method embodiments.

[0162] It is worth mentioning that each module involved in the above embodiments can be a single physical unit, a part of a single physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units are absent in this embodiment.

[0163] A third aspect of this application relates to an electromagnetic wave sensor, comprising: a carrier, an integrated circuit disposed on the carrier, and an antenna disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device disposed on the carrier. The integrated circuit is connected to the antenna and is used to process echo signals received by the antenna. The integrated circuit is the same as the one provided in the foregoing embodiments. The integrated circuit is the same as the one provided in any embodiment of this application.

[0164] When the antenna and integrated circuit are not integrated into a single device, the integrated circuit is connected to the antenna via a first transmission line, which can be a printed circuit board (PCB) trace. The carrier can be a printed circuit board (PCB), such as a development board, data acquisition board, or the motherboard of a device, etc., which will not be elaborated on here.

[0165] Since the structure and working principle of the integrated circuit included in the electromagnetic wave sensor have been described in detail in the above embodiments, they will not be repeated here.

[0166] This application provides a terminal device, which may include: a device body; and an electromagnetic wave sensor as described above, disposed on the device body; wherein the electromagnetic wave sensor is used for target detection and / or communication to provide reference information for the operation of the device body.

[0167] In some embodiments, the electromagnetic wave sensor may be disposed on the exterior of the device body. In other embodiments, the electromagnetic wave sensor may be disposed on the interior of the device body. In still other embodiments, the electromagnetic wave sensor may be partially disposed on the interior of the device body and partially disposed on the exterior of the device body. This application does not limit the specific embodiments; the choice depends on the circumstances.

[0168] It should be noted that electromagnetic wave sensors can achieve functions such as target detection by transmitting and receiving radio signals, providing measurement information of the detected target to the device body, thereby assisting or even controlling the operation of the device body. Examples of measurement information include at least one of relative distance, relative speed, and relative angle.

[0169] In some embodiments, the device body described above can be a component or product applied in fields such as transportation, consumer electronics, monitoring, in-cabin detection, and healthcare. For example, the device body can be intelligent transportation equipment (such as automobiles, motorcycles, ships, subways, trains, etc.), security equipment (such as cameras), liquid level / flow rate detection equipment, smart wearable devices (such as wristbands, glasses, etc.), smart home devices (such as robot vacuum cleaners, door locks, televisions, air conditioners, smart lights, etc.), various communication devices (such as mobile phones, tablets, etc.), as well as devices such as barriers, intelligent traffic lights, intelligent signs, traffic cameras, and various industrial robotic arms (or robots). It can also be various instruments used to detect vital signs parameters and various devices equipped with such instruments, such as in-cabin detection in automobiles, indoor personnel monitoring, intelligent medical devices, and consumer electronic devices.

[0170] In some embodiments, when the aforementioned device body is applied to an Advanced Driving Assistance System (ADAS), the electromagnetic wave sensor, as an on-board sensor, can provide various functional safety guarantees for the ADAS system, such as Automatic Emergency Braking (AEB), Blind Spot Detection (BSD), Lane Changing Assist (LCA), and Rear Cross Traffic Alert (RCTA).

[0171] Furthermore, the examples mentioned in the above embodiments can be freely combined, and any combination can be understood as an embodiment. The terms "embodiment" or "example" appearing in various locations in the specification do not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand that the embodiments described herein can be combined with other embodiments.

[0172] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A radar-based target measurement method, characterized in that, include: Acquire radar echo signals; The target is measured based on the radar echo signal to obtain a first measurement value; Based on the first measurement value, a reference signal transmission model is determined from the preset signal transmission models, wherein each signal transmission model corresponds to a type of signal transmission path; The second measurement value is obtained by calculation based on the reference signal transmission model and the radar echo signal.

2. The radar-based target measurement method according to claim 1, characterized in that, The signal transmission model includes at least one model based on a single signal transmission path, and / or at least one multipath model, wherein each of the multipath models is based on at least two different single signal transmission paths.

3. The radar-based target measurement method according to claim 2, characterized in that, The single signal transmission path includes at least one of the following paths: radar-target-radar, radar-target-reflector-radar, radar-reflector-target-radar, or radar-reflector-target-reflector-radar.

4. The radar-based target measurement method according to claim 2, characterized in that, The single signal transmission paths corresponding to different multipath models are not exactly the same, and / or the model weights of the same single signal transmission path corresponding to different multipath models are different.

5. The radar-based target measurement method according to any one of claims 1 to 4, characterized in that, The step of determining a reference signal transmission model from a preset set of signal transmission models based on the first measurement value includes: Based on the first measurement value, the effective signal components of the radar echo signal under each of the signal transmission models are determined respectively; The reference signal transmission model is determined based on the effective signal components corresponding to the radar echo signal under each of the aforementioned signal transmission models.

6. The radar-based target measurement method according to claim 5, characterized in that, The effective signal components of the radar echo signal under each of the signal transmission models are determined based on the first measurement value, using the following expression: Where, x i ′ The effective signal component of the radar echo signal under the i-th signal transmission model and when the target has the first measurement value relative to the radar. Representing matrix A i The conjugate transpose of the matrix. x i The modeling representation of the radar echo signal under the i-th signal transmission model is as follows: A ti A is the radar transmitting antenna steering vector under the i-th signal transmission model determined based on the first measurement value. ri ρ is the radar receiving antenna steering vector under the i-th signal transmission model determined based on the first measurement value. i Let n be the amplitude representation of the effective signal under the i-th signal transmission model. i Let be the noise representation under the i-th signal transmission model, where max y1 represents the operation of finding the maximum value of function y1, and ||y2|| represents the operation of finding the modulus of vector y2. This represents the Kronecker product operation.

7. The radar-based target measurement method according to claim 6, characterized in that, When the first measurement includes altitude and / or pitch angle, the following conditions are met: In the signal transmission model, the radar transmitting antenna steering vector and radar receiving antenna vector corresponding to the radar-target-radar signal transmission path are both obtained based on the target's elevation angle relative to the radar determined by the first measurement value. And / or, The radar transmitting antenna steering vector corresponding to the signal transmission path of radar-target-reflector-radar in the signal transmission model is obtained based on the elevation angle of the target relative to the radar determined by the first measurement value, and the radar receiving antenna steering vector is obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar determined by the first measurement value. And / or, The radar transmitting antenna steering vector corresponding to the signal transmission path of radar-reflector-target-radar in the signal transmission model is obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar, which is determined by the first measurement value; the radar receiving antenna steering vector is obtained based on the elevation angle of the target relative to the radar, which is determined by the first measurement value. And / or, In the signal transmission model described above, the steering vectors of the radar transmitting antenna and the radar receiving antenna corresponding to the signal transmission path from radar to reflector to target to reflector to radar are both obtained based on the elevation angle of the incident point of the signal on the reflector relative to the radar, as determined by the first measurement value.

8. The radar-based target measurement method according to claim 7, characterized in that, The elevation angle of the signal incident point on the reflector surface relative to the radar, determined by the first measurement. Determined by the following expression: in, Let α be the elevation angle of the target relative to the radar, determined by the first measurement, and let α be the angle formed by the reflecting surface and the horizontal plane.

9. The radar-based target measurement method according to claim 8, characterized in that, The angle formed by the reflector and the horizontal plane is determined through iterative optimization as an unknown quantity. The initial value for iterating the angle formed by the reflector and the horizontal plane is a preset value, or the initial value for iterating the angle formed by the reflector and the horizontal plane is obtained by multipath reflection estimation based on the positions of several target points, wherein the positions of the target points are obtained based on the radar echo signal.

10. The radar-based target measurement method according to claim 9, characterized in that, When the first measurement includes height, the position of the target point is represented by the target's height and longitudinal depth relative to the radar; The angle formed between the reflecting surface and the horizontal plane is determined in the following way: The position of the target point is converted into a coordinate point in a coordinate system with the target's height as the vertical axis and the longitudinal depth relative to the radar as the horizontal axis; The transformed coordinate points are fitted to a curve that serves as a reflecting surface, thereby determining the angle between the reflecting surface and the horizontal plane.

11. The radar-based target measurement method according to claim 10, characterized in that, The fitting of the transformed coordinate points is achieved by any of the following algorithms: least squares fitting algorithm, higher-order polynomial fitting algorithm.

12. The radar-based target measurement method according to claim 5, characterized in that, The step of determining the reference signal transmission model based on the effective signal components corresponding to the radar echo signal under each of the aforementioned signal transmission models includes: The maximum effective signal component of the radar echo signal is determined from the effective signal components corresponding to each of the signal transmission models. The signal transmission model corresponding to the maximum effective signal component of the radar echo signal is used as the reference signal transmission model.

13. The radar-based target measurement method according to claim 12, characterized in that, Determining the maximum effective signal component of the radar echo signal from the effective signal components corresponding to each of the signal transmission models includes: Based on the effective signal components of the radar echo signal under each of the signal transmission models, the matching parameters corresponding to each of the signal transmission models are determined, so that the matching parameters are used as a representation of the relative magnitude of the effective signal components under the corresponding signal transmission models.

14. The radar-based target measurement method according to claim 13, characterized in that, The matching parameters are determined by at least one of the following expressions: η2 i =‖x i ‖-‖x i ′ ‖; wherein η1 i , η2 i are different representations of the matching parameter or different elements of the matching parameter under the i-th signal transmission model, respectively, x i ′ is an effective signal component under the i-th signal transmission model, x i is a modeled representation of the radar echo signal under the i-th signal transmission model, and ||y2|| denotes an operation of taking the modulus of the vector y2.

15. The radar-based target measurement method according to claim 5, characterized in that, The step of determining the reference signal transmission model based on the effective signal components corresponding to the radar echo signal under each of the aforementioned signal transmission models includes: The reference transmission model is determined based on the effective signal components corresponding to the radar echo signal under each of the signal transmission models, and the trained network model.

16. The radar-based target measurement method according to any one of claims 1 to 4, characterized in that, The step of measuring the target based on the radar echo signal to obtain a first measurement value includes: The first measurement value is obtained by measuring the target based on the radar echo signal in a scenario without multipath interference.

17. The radar-based target measurement method according to any one of claims 1 to 4, characterized in that, The first measurement and the second measurement include at least one of the following parameters: altitude, pitch angle, azimuth angle, lateral distance, and longitudinal distance.

18. An integrated circuit, characterized in that, It includes a radio frequency module, an analog signal processing module, and a digital signal processing module connected in sequence; The radio frequency module is used to generate radio frequency transmission signals and receive radio frequency reception signals; The analog signal processing module is used to down-frequency the received radio frequency signal to obtain an intermediate frequency signal. The digital signal processing module is used to perform analog-to-digital conversion on the intermediate frequency signal, and to process the digital data obtained by analog-to-digital conversion using the radar-based target measurement method as described in any one of claims 1 to 17, so as to achieve target measurement.

19. An electromagnetic wave sensor, characterized in that, include: Carrier; The integrated circuit as described in claim 18 is disposed on the carrier. An antenna is disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device and disposed on the carrier. The integrated circuit is connected to the antenna and is used to transmit radio frequency signals and / or receive radio frequency signals.

20. A terminal device, characterized in that, include: Equipment body; And the electromagnetic wave sensor as described in claim 19, which is disposed on the device body; The electromagnetic wave sensor is used for target detection, target measurement and / or communication to provide reference information for the operation of the device body.

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