Method for judging angle imbalance of vehicle-mounted radar

Abstract

The invention discloses a method for judging the existence of angle imbalance of a vehicle-mounted radar. The method comprises the following steps: determining a horizontal angle and a vertical angle of a target in a point cloud generated by the radar relative to the normal direction of the radar, and obtaining a fast angle of the horizontal angle or a fast angle of the vertical angle; calculating variance and standard deviation for fast angles of all horizontal angles or vertical angles in the time domain window taking the current moment as the ending moment; if the variance is less than a non-zero positive integer multiple of the standard deviation, performing a second sub-process for the horizontal angle or the vertical angle; and the second sub-process comprises the following steps: if the fast angle of the horizontal angle or the fast angle of the vertical angle exceeds a preset limit value, determining that the vehicle-mounted radar has angle imbalance and sending out an alarm for executing calibration on the radar.

Description

Technical Field

[0001] The present application generally relates to a method for determining whether an angular misalignment exists in a vehicle-mounted radar, so as to reduce the probability of a false alarm of the angular misalignment. Background Art

[0002] When manufacturing a motor vehicle, a radar, such as a millimeter wave radar, is fixedly installed in a specific part of the motor vehicle and calibrated so as to generate a suitable calculation process of the vehicle navigation system when working. For example, the data in the point cloud acquired by the radar can first be processed by a digital signal processor (DSP) to convert it into data that can be processed by the perception module in the vehicle navigation system. The data includes the angle of the target in the point cloud relative to the normal direction of the radar, for example, the angle can be decomposed into a horizontal angle and a vertical angle relative to the ground. After the motor vehicle leaves the factory, it is necessary to regularly check the received data during the use of the radar to determine whether the motor vehicle needs to be calibrated (alignment) due to a change in the installation and fixing direction of the radar. In other words, if the radar does have an angular misalignment (misalignment) due to a change in the installation and fixing direction of the radar, it is necessary to calibrate the radar in time to prevent the data received by the radar from generating unexpected deviations, thereby causing navigation distortion and even affecting the safe driving of the motor vehicle. Usually, calibration takes a long time, during which the vehicle navigation system will not be available.

[0003] During normal use of a motor vehicle, the data received by the radar may reflect the misjudgment of the angle misalignment of the radar due to intense driving, emergency braking, or uphill and downhill driving, even though the radar is actually installed in the same direction as before. However, if the radar is frequently calibrated only due to misjudgment based on data (misjudgment of angle misalignment), it will occupy too much computing resources of the motor vehicle navigation system or affect the driving experience, and sometimes even affect the safe driving of the motor vehicle. Summary of the invention

[0004] In response to the above problems, the present application aims to propose an improved method for determining whether a radar has an angle misalignment, so as to avoid and reduce the misjudgment of radar angle misalignment caused by factors such as uphill and downhill driving of a motor vehicle and sudden acceleration and deceleration, and to provide a basis for accurate calibration of the radar.

[0005] According to one aspect of the present application, there is provided a method for determining whether an on-vehicle radar has an angle misalignment, comprising: determining an angle of a target in a point cloud generated by the radar relative to a normal direction of the radar, wherein the angle comprises a horizontal angle and a vertical angle;

[0006] Performing fast filtering on the horizontal angle or the vertical angle to obtain a fast angle of the horizontal angle or a fast angle of the vertical angle;

[0007] The following first sub-process is performed for the fast angle of the horizontal angle or the vertical angle, and the first sub-process includes the following steps:

[0008] 1) Calculate the variance and standard deviation of the fast angles of all horizontal angles or vertical angles in the time domain window with the current time as the end time;

[0009] 2) If the variance is less than a non-zero positive integer multiple of the standard deviation, then execute the second sub-process for the horizontal angle or the vertical angle; otherwise, execute step 1) for the next moment;

[0010] The second sub-process for horizontal angle or vertical angle includes the following steps:

[0011] 3) performing slow filtering on the horizontal angle or the vertical angle to obtain a slow angle of the horizontal angle or a slow angle of the vertical angle;

[0012] 4) If the slow angle of the horizontal angle or the slow angle of the vertical angle exceeds a predetermined limit value for the slow angle of the horizontal angle or the slow angle of the vertical angle, the current slow angle is updated to the predetermined limit value for the slow angle of the horizontal angle or the slow angle of the vertical angle; otherwise, continue to execute step 3) for the next moment;

[0013] 5) If the fast angle of the horizontal angle or the fast angle of the vertical angle exceeds a predetermined limit, it is determined that there is an angle misalignment in the vehicle-mounted radar and an alarm is issued to calibrate the radar.

[0014] Optionally, a first sub-process for a fast angle of a horizontal angle is executed synchronously with a first sub-process for a fast angle of a vertical angle; and / or a second sub-process for a horizontal angle is executed synchronously with a second sub-process for a vertical angle.

[0015] Optionally, in the second sub-process, the non-zero positive integer multiple of the standard deviation is three times the standard deviation.

[0016] Optionally, in the first sub-process, the second sub-process is executed only when the number of times that the variance is determined to be smaller than a non-zero positive integer multiple of the standard deviation reaches a predetermined threshold.

[0017] Optionally, in the first sub-process, the predetermined threshold value for the horizontal angle is an integer between 2 and 100; and the predetermined threshold value for the vertical angle is an integer between 2 and 100.

[0018] Optionally, in the first sub-process, when the variance is calculated for the horizontal angle, the expected value for the horizontal angle is ±5.7°; and when the variance is calculated for the vertical angle, the expected value for the vertical angle is ±6.3°.

[0019] Optionally, in the second sub-process, the predetermined limit value for the horizontal angle is the same as the expected value for the horizontal angle; and / or the predetermined limit value for the vertical angle is the same as the expected value for the vertical angle.

[0020] Optionally, after an alarm is issued to perform calibration on the radar, the counter is reset to zero, and the first sub-process for the fast angle of the horizontal angle and / or the fast angle of the vertical angle is performed again.

[0021] Optionally, independent of the execution of the first sub-process and / or the second sub-process, if the motor vehicle is detected to be stationary for more than a predetermined time, it is determined that there is an angular misalignment of the on-board radar and an alarm is issued to calibrate the radar.

[0022] Optionally, the vehicle-mounted radar is a vehicle-mounted forward radar or a corner radar.

[0023] According to another aspect of the present application, a vehicle-mounted domain controller is also provided, which is configured to be connected to the vehicle-mounted radar data and execute the steps of the aforementioned method.

[0024] According to another aspect of the present application, a computer program product is provided, which includes a computer program or instructions, wherein the computer program or instructions implement the steps of the aforementioned method when executed by a processor.

[0025] The use of the above-mentioned technical means of the present application can significantly reduce the possibility of false alarm of radar angle misalignment caused only by abnormal radar reception data (rather than actual angle misalignment of the radar), thereby reducing the probability of undesired calibration of the radar, improving the driving experience of motor vehicle drivers, and further improving the working efficiency and accuracy of the navigation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The principles and various aspects of the present application can be more fully understood from the following detailed description in conjunction with the following drawings. It should be noted that the scales of the drawings may be different for the purpose of clear description, but this will not affect the understanding of the present application. In the drawings:

[0027] Figure 1 A diagram schematically shows the angle relationship from the target in the point cloud to the radar when the radar is judged to be out of angle;

[0028] Figure 2 A flow chart of a method for determining angle misalignment of a radar according to the prior art is schematically shown;

[0029] Figure 3 A diagram schematically shows the time variation of each signal during the angle processing of the target relative to the radar R in the point cloud generated by the radar received signal;

[0030] Figure 4 A flowchart of a method for determining whether a radar has an angle misalignment according to an embodiment of the present application is schematically shown; and

[0031] Figure 5 A flow chart of a method for determining whether a radar has an angular misalignment according to another embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0032] In the various figures of the present application, features with the same structure or similar functions are represented by the same reference numerals.

[0033] For illustrative purposes only, Figure 1 The angle relationship of the target in the point cloud received by the radar relative to the normal direction of the radar is shown. Figure 1 In the figure, reference symbol R represents radar; reference symbol RN represents the normal direction of the radar, for example, the normal direction can be defined by the normal direction of the main lobe of energy emitted by the radar; reference symbol C represents the point cloud generated by the signal received by the radar, for example, the raw data received by the radar can be processed by a DSP into the point cloud information in a manner familiar to those skilled in the art; reference symbol O represents a target in the point cloud, for example, the target can be the purpose of navigation judgment in the vehicle navigation system. Figure 1 The left sub-figure in Figure 1 shows the spatial relationship between the radar R and the point cloud C. Figure 1 The right sub-figure in shows the target O and the radar R in the point cloud C in the plane perpendicular to the normal direction RN of the radar R, as well as the angular relationship between the two. Figure 1 In the right sub-figure of , the angle of the target O relative to the normal direction RN of the radar R can be decomposed into a horizontal angle AH and a vertical angle AV relative to the ground. It should be clear to those skilled in the art that the radar R designed in the present application is a vehicle-mounted radar, which includes but is not limited to a vehicle-mounted forward radar, a corner radar, etc. Therefore, the method or steps described below can be applied to radars configured on motor vehicles such as vehicle-mounted forward radars and corner radars.

[0034] In determining the angular misalignment of the radar, it is mainly determined whether the horizontal angle AH and the vertical angle AV have deviations sufficient to require calibration of the radar. Figure 2 The method of determining the angle misalignment of the radar according to the prior art is shown. It should be understood that during the operation of the motor vehicle or the radar, the determination is completed each time the radar receives and processes a signal. Figure 2As shown, in step S100, the original signal received by the radar R is processed by DSP in any manner familiar to the art, and the data obtained includes the horizontal angle AH and the vertical angle AV of the target O relative to the radar R. In step S200, the horizontal angle AH or the vertical angle AV is filtered, for example, the same horizontal angle AH or the same vertical angle AV is processed by the fast filter FF and the slow filter SF well known to those skilled in the art. As follows, only the horizontal angle AH is used as an example for explanation. In step S200, a horizontal angle AHF (also called a fast angle) processed by a fast filter and a horizontal angle AHS (also called a slow angle) processed by a slow filter are generated. Then, in step S310, it is determined whether the slow angle AHS obtained in step S200 exceeds a predetermined limit value T HS If it is determined in step S310 that the slow angle AHS exceeds the predetermined limit value T HS , then in step S320 the current slow angle AHS is defined as the predetermined limit value T HS , and returns to step S100 to restart the next cycle of receiving and processing signals. If it is determined in step S310 that the slow angle AHS does not exceed the predetermined limit value T HS , then directly returns to step S100 to restart the next cycle of receiving and processing signals. At the same time, in step S300, it is determined whether the fast angle AHF obtained in step S200 exceeds a predetermined limit value T HS , where the predetermined limit value T HS It can be the limit value that has been updated in the previous cycle of receiving and processing the signal or the predetermined limit value T that is still used in the previous cycle of receiving and processing the signal. HS If it is determined in step S300 that the fast angle AHF has exceeded the predetermined limit value T H s, then go to step S330. In step S330, for example, the current cycle of receiving and processing signals of the radar R may be terminated, and the calibration process of the radar R may be entered (not shown in the figure); or, an alarm may be issued to calibrate the radar. If it is determined in step S300 that the fast angle AHF does not exceed the predetermined limit value T H s, then directly returns to step S100 to restart the next cycle of receiving and processing signals. For the vertical angle AV, the above process is performed synchronously. For example, in step S200, a vertical angle AVF (also called a fast angle) processed by fast filtering and a vertical angle AVS (also called a slow angle) processed by slow filtering are generated. Then, in step S310, it is determined whether the slow angle AVS obtained in step S200 exceeds a predetermined limit value T VS If it is determined in step S310 that the slow angle AVS exceeds the predetermined limit value T VS, then in step S320 the current slow angle AVS is defined as the predetermined limit value T VS , and returns to step S100 to restart the next cycle of receiving and processing signals. If it is determined in step S310 that the slow angle AVS does not exceed the predetermined limit value T VS , then directly returns to step S100 to restart the next cycle of receiving and processing signals. At the same time, in step S300, it is determined whether the fast angle AVF obtained in step S200 exceeds the predetermined limit value T VS , where the predetermined limit value T VS It can be the limit value that has been updated in the previous cycle of receiving and processing the signal or the predetermined limit value T that is still used in the previous cycle of receiving and processing the signal. VS If it is determined in step S300 that the fast angle AVF has exceeded the predetermined limit value T V s, then go to step S330. In step S330, for example, the current cycle of receiving and processing signals of the radar R may be terminated, and the calibration process of the radar R may be entered (not shown in the figure); or, an alarm may be issued to calibrate the radar. If it is determined in step S300 that the fast angle AVF does not exceed the predetermined limit value T V s, then directly returns to step S100 to restart the next cycle of receiving and processing signals.

[0035] exist Figure 2 In the method shown in the figure, if in each cycle, whether the horizontal angle AH or the vertical angle AV exists in step S300, the fast angle AHF or AVF has exceeded the predetermined limit value T H s or T V s, then it is necessary to go to step S330.

[0036] exist Figure 2In the method of the prior art shown, since all the judgment steps are based on the time domain signal (for example, the angle of the target O in the point cloud relative to the normal direction RN of the radar R), some abnormal signals in the time domain signal will also cause the radar R to be calibrated. Sometimes, these abnormal signals are not caused by the actual angle misalignment of the radar R, but are simply caused by reasons such as rapid acceleration and deceleration, uphill and downhill of the motor vehicle. In these cases, in fact, the radar R itself has not changed in the installation and fixing direction relative to the motor vehicle, but if the radar R still needs to be calibrated according to the judgment method of the prior art, it obviously occupies too much computing burden; at the same time, since the accuracy of the navigation system is inevitably reduced during the calibration process, it will affect the safety of the motor vehicle driving or affect the driving experience. In addition, the above-mentioned abnormal signals may appear frequently during the normal driving of the motor vehicle due to road traffic congestion, road undulations, etc., so that the judgment method of the prior art will cause the radar R to be frequently calibrated, occupying a large amount of computing resources and time, and affecting the driving experience of the motor vehicle driver.

[0037] Figure 3 The diagram schematically shows the changes of each signal over time during the angle processing of the target O in the point cloud generated by the signal received by the radar R relative to the radar R, wherein curve 1 represents the angle of the target O in the point cloud processed by the DSP relative to the normal direction RN of the radar R, which can be considered as the horizontal angle AH or the horizontal angle signal; curve 2 represents the fast angle obtained after fast filtering the horizontal angle AH acquired in real time; curve 3 represents the slow angle obtained after slow filtering the horizontal angle AH acquired in real time; curve 4 represents the predetermined limit value updated based on the slow angle and used to judge whether the fast angle exceeds the limit. It can be seen that there are abnormal signal peaks such as 1_A and 1_B in curve 1. If the following is adopted Figure 2 If the method of the prior art shown in the figure is used for judgment, these abnormal signal peaks will inevitably result in entering step S330. However, according to the actual running state of the motor vehicle, these abnormal signal peaks 1_A and 1_B are often only caused by the motor vehicle's rapid acceleration and deceleration or uphill and downhill. Therefore, in order to eliminate the influence of these abnormal signal peaks 1_A and 1_B on the radar angle misalignment judgment result, the method for judging whether the radar has angle misalignment according to the present application is introduced.

[0038] It should be understood that the method or each step of the method described below in the present application can exist in the form of a computer program product, wherein the computer program product includes a program or instruction for implementing the method and / or each step of the method of the present application, and the program or instruction can implement the method and / or each step of the method of the present application when called and executed by the processor. Within the scope of the present application, the processor can be a processor or a computing unit of a perception module of a vehicle-mounted navigation system or other processor for processing data received by the radar. Here, the processor can be understood as any suitable computer or computing unit capable of executing a program or instruction. In addition, a vehicle-mounted domain processor is usually configured on a motor vehicle. This vehicle-mounted domain processor can also be understood as a computer capable of implementing each step of the method and / or the method described in the present application. The vehicle-mounted domain processor can be connected to the radar R by data (for example, connected via a vehicle-mounted bus), so that the data actually received by the radar R can be obtained and stored and processed.

[0039] The premise of the method for judging whether the radar has angle misalignment according to the present application is: it is assumed that under normal circumstances, the angle of the target O to the normal direction RN of the radar R in a certain time domain window can correctly reflect the change of the radar angle misalignment and satisfies a random distribution such as a normal distribution. Therefore, in order to eliminate the influence of the change of the angle of the target O to the normal direction RN of the radar R that cannot correctly reflect the radar angle misalignment on the judgment result, the statistical principle is used to judge whether the filtered fast angle change of the angle of the target O to the normal direction RN of the radar R recorded in a certain time domain window accurately reflects the phenomenon of radar angle misalignment. In addition, since each calibration of the radar will occupy a certain amount of computing resources, it can be adopted that if the number of times that can accurately reflect the radar angle misalignment reaches a threshold, the fast angle is compared with the predetermined limit value to judge whether the radar needs to be calibrated to save computing resources.

[0040] Refer to the following Figure 4 A flow chart of a method for determining whether a radar has an angular misalignment according to an embodiment of the present application is introduced.

[0041] In step S10, the original signal received by the radar R is processed by DSP in any manner familiar to the art to obtain data including the angle of the target O relative to the normal direction RN of the radar R, wherein the angle of the target O relative to the normal direction RN of the radar R can be divided into a horizontal angle AH and a vertical angle AV. In the illustrated embodiment, only the horizontal angle AH is used as an example to illustrate the method of the present application. However, it should be clear to those skilled in the art that the method of the present application can also be implemented with the vertical angle AV, or the method of the present application can be implemented with the horizontal angle AH and the vertical angle AV in parallel. It should be understood that the method steps described below in the present application are implemented in a radar (e.g. Figure 1 The vehicle-mounted radar R) shown in the figure is executed a certain time after being turned on, so as to facilitate the data processing steps related to the time domain window mentioned later.

[0042] In step S11, the horizontal angle AH obtained in step S10 (here, the horizontal angle AH can be understood as the signal of the horizontal angle AH obtained in real time) is subjected to fast filtering (FF) processing to obtain a real-time (horizontal) fast angle. Then, in step S12, variance distribution statistics are performed on the real-time fast angle obtained by processing in step S11 within the range of the time domain window length from the current moment to the previous moment.

[0043] For example, the length of the time domain window can be determined according to requirements such as computational burden and / or computational accuracy, and the length of the time domain window can be constant or variable. In addition, the position of the time domain window is limited by the moment at which the horizontal angle AH involved in the current (e.g., step S11 or step S12) is located. The time domain window can also be considered as a sample space, in which there are n samples (n is an integer greater than 1), and these n samples correspond to the n horizontal angles AH recorded in the time domain window. The order of these n samples can correspond to the time order of each horizontal angle AH recorded in the time domain window.

[0044] For this sample space, calculate the variance s n For example, the variance can be calculated as follows:

[0045]

[0046] Among them, x i represents the value of the i-th sample in the sample space (for example, it can be the value of the horizontal angle AH at the time corresponding to i in the time domain space), Represents the expected value for the sample in the sample space. Taking the horizontal angle as an example, the expected value can be a pre-set value, such as ±5.7°. For the horizontal angle, there are angles in positive and negative (left and right) opposite directions relative to the normal direction RN of the radar R. When the horizontal angle in a certain direction is considered positive for judgment, the expected value of the horizontal angle can be 5.7°; and when the horizontal angle in the opposite direction is used for judgment, the expected value of the horizontal angle can be -5.7°. For the vertical angle, the expected value can be, for example, ±6.3°. For example, when the vertical angle in the upward direction is considered positive for judgment, the expected value of the vertical angle can be 6.3°; and when the vertical angle in the opposite downward direction is considered negative for judgment, the expected value of the vertical angle can be -6.3°.

[0047] Next, for this sample space, calculate the standard deviation σ nFor example, the relationship between the standard deviation and the variance can be

[0048] For example, in Figure 3 In the above, LT represents the time domain window, and t0, t1, t2, ..., t j = respectively represent that the angles (curve 1, such as horizontal angle or vertical angle) of the target O in the point cloud processed by the DSP relative to the normal direction RN of the radar R are processed as mentioned in the above steps S100 to S200 at these moments, wherein j can be an integer greater than zero, and its size can depend on the running time of the radar R. |t j -t j-1 | can be considered as the time domain interval between the time domain adjacent angles of the target O in the point cloud processed by the DSP relative to the normal direction RN of the radar R. The time domain length of the time domain window LT is, for example, for each t0, t1, t2, ..., t j can be fixed, or alternatively for t0, t1, t2, ..., t j Some or all of may also be varied. It should be clear that Figure 3 The time points t0, t1, t2, ..., t j This is only for illustration and does not mean that the actual time domain sampling points for curve 1 are the points shown.

[0049] For example, the above step S10 may be performed starting from time t0. The time t0 may be the time when the radar R is powered on for a period of time (e.g., 1 second later), or may be the time when the radar R is just calibrated. For example, at time t0, the fast angles of all horizontal angles in the corresponding time domain window LT after fast filtering may be regarded as samples in a sample space, and their variances s may be determined. n and standard deviation σ n For another example, at time t j , its corresponding time domain window LT (the time domain window LT has been translated in the time domain by a length |t relative to the time domain window LT at time t0) j The fast angles of all horizontal angles within -t0|) after fast filtering are regarded as samples in a sample space, and their variance s is determined n and standard deviation σ n .

[0050] Then go to Figure 4 In step S13, the standard deviation σ of the sample space is n The confidence level is determined by an integer multiple of , for example, three times the standard deviation, and the variance s of the sample space is determined. nIf the judgment result of step S13 is yes, go to step S14; if not, go to step S10, and continue to use DSP to process the original signal received by the radar R at the next moment in any manner familiar to the art to obtain data including the angle of the target O relative to the normal direction RN of the radar R.

[0051] In step S14, let the counter J accumulate 1. Then, in step S15, it is determined whether the counter J exceeds a threshold value Jmax. For example, the threshold value can be an integer greater than 1, such as a suitable integer between 2 and 50 or between 50 and 100, 200 or 300. Preferably, the threshold value is 100. If the determination result of step S15 is no, then go to step S10, and continue to process the original signal received by the radar R at the next moment by using the DSP in any manner familiar to the art to obtain data including the angle of the target O relative to the normal direction RN of the radar R.

[0052] If the judgment result of step S15 is yes, then go to step S100'. From step S100', it is possible to refer to Figure 2 The method or method steps described are Figure 4 In the embodiment of the present application, the above-described steps S12 and S13 are mainly used to realize the use of statistical principles to determine whether there is a phenomenon of rapid angle change that accurately reflects the misalignment of the radar angle. In fact, the existence of step S14 is to reduce the computational burden. This is because calibrating the radar will take up certain computing resources. If step S100' is only turned to when the number of times that can accurately reflect the misalignment of the radar angle reaches a threshold, computing resources can be further saved. Of course, it is clear to those skilled in the art that step S14 can be omitted in one embodiment of the present application. In addition, the selection of the threshold in step S14 is related to factors such as the performance of the computer hardware used to execute the method of the present application and the calibration requirements for the radar.

[0053] In step S100', the original signal received by the radar R is processed by DSP in any manner familiar to the art, and the data obtained includes the horizontal angle AH of the target O relative to the radar R. In step S200', the horizontal angle AH is filtered, for example, the same horizontal angle AH is processed by fast filtering FF and slow filtering SF known to those skilled in the art, thereby generating a horizontal angle AHF processed by fast filtering (also referred to as a fast angle) and a horizontal angle AHS processed by slow filtering (also referred to as a slow angle). In an alternative or optional embodiment, the execution of step S100' can be for the current moment or the next moment when steps S10 to S15 are executed. In the case where the execution of step S100' is for the current moment when steps S10 to S15 are executed, the fast angle obtained in step S11 can also be directly called without recalculating.

[0054] Next, in step S310', it is determined whether the slow angle AHS obtained in step S200 exceeds a predetermined limit value T HS If it is determined in step S310' that the slow angle AHS exceeds the predetermined limit value T HS , then in step S320' the current slow angle AHS is defined as the predetermined limit value T HS , and returns to step S100' to restart the next cycle of receiving and processing signals. If it is determined in step S310' that the slow angle AHS does not exceed the predetermined limit value T HS , then directly returns to step S100' to restart the next cycle of receiving and processing signals. At the same time, in step S300', it is determined whether the fast angle AHF obtained in step S200' exceeds the predetermined limit value T HS , where the predetermined limit value T HS It can be the limit value that has been updated in the previous cycle of receiving and processing the signal or the predetermined limit value T that is still used in the previous cycle of receiving and processing the signal. HS If it is determined in step S300' that the fast angle AHF has exceeded the predetermined limit value T H s, then go to step S330'. In step S330', for example, the current cycle of receiving and processing signals of the radar R may be terminated, and the radar R calibration process (not shown in the figure) may be entered instead. Alternatively, an alarm may be issued to calibrate the radar. If it is determined in step S300' that the fast angle AHF does not exceed the predetermined limit value T H s, then directly returns to step S100' to restart the next cycle of receiving and processing signals. For example, after calibrating the radar R or issuing an alarm for calibrating the radar, the counter J can be reset to zero to restart the execution of the above method steps.

[0055] It should be clear that, in one embodiment of the present application, the above-mentioned predetermined limit value T is adjusted by using the slow angle AHS. HS The update can be completed synchronously during the processing of steps S10 to S15. It should be clear to those skilled in the art that the start of step S10 can be performed a certain time after the radar R is turned on or alternatively can be started after the radar R is calibrated last time (for example, after the above step S330' is executed).

[0056] Figure 4 The method steps S10 to S15 shown are performed for horizontal angles, but the method steps S10 to S15 can also be performed synchronously for vertical angles. Regardless of which angle the steps S10 to S15 are performed for, if the judgment result of step S15 is yes, it can directly go to step S100' for the corresponding horizontal angle or vertical angle.

[0057] Figure 5 A flowchart of a non-limiting example of a method for synchronously judging whether the radar R has an angle misalignment for the horizontal angle AH and the vertical angle AV is given. It can be seen that in the previous processing steps S10 to S15 for the horizontal angle AH and the vertical angle AV, whether the judgment result of step 15 for the horizontal angle AH or step S15 for the vertical angle AV is yes, it will jump to the execution sub-process of the corresponding steps S100' to S330' for the horizontal angle AH or the vertical angle AV. In particular, in the execution sub-process of steps S100' to S330' for the vertical angle AV, in step S100', the original signal received by the radar R is processed by DSP in any manner familiar to the art, and the data obtained includes the vertical angle AV of the target O relative to the radar R. In step S200', the vertical angle AV is filtered, for example, the same vertical angle AV is processed by fast filtering FF and slow filtering SF known to those skilled in the art, thereby generating a horizontal angle AVF (also called a fast angle) processed by fast filtering and a horizontal angle AVS (also called a slow angle) processed by slow filtering. Next, in step S310', it is determined whether the slow angle AVS obtained in step S200 exceeds a predetermined limit value T VS If it is determined in step S310' that the slow angle AVS exceeds the predetermined limit value T HS , then in step S320' the current slow angle AVS is defined as the predetermined limit value T VS , and returns to step S100' to restart the next cycle of receiving and processing signals. If it is determined in step S310' that the slow angle AVS does not exceed the predetermined limit value T VS, then directly returns to step S100' to restart the next cycle of receiving and processing signals. At the same time, in step S300', it is determined whether the fast angle AVF obtained in step S200' exceeds the predetermined limit value T VS , where the predetermined limit value T VS It can be the limit value that has been updated in the previous cycle of receiving and processing the signal or the predetermined limit value T that is still used in the previous cycle of receiving and processing the signal. VS If it is determined in step S300' that the fast angle AVF has exceeded the predetermined limit value T V s, then go to step S330'. In step S330', for example, the current cycle of receiving and processing signals of the radar R may be terminated, and the radar R calibration process (not shown in the figure) may be entered instead. Alternatively, an alarm may be issued to calibrate the radar. If it is determined in step S300' that the fast angle AVF does not exceed the predetermined limit value T V s, then directly returns to step S100' to restart the next cycle of receiving and processing signals.

[0058] It should be clear that the above predetermined limit value T V s may be the same as the expected value for the vertical angle, and / or the predetermined limit T H s may be the same as the expected value for the vertical angle.

[0059] According to another non-limiting embodiment of the present application, Figure 4 and 5 The described method or method steps or their modifications can be independently used to determine whether the motor vehicle is stationary and for how long based on other sensors of the motor vehicle, such as tire pressure sensors, speed sensors, etc. If the motor vehicle is detected to be stationary for more than a predetermined time (e.g., 60 seconds) after starting, an alarm is issued to calibrate the radar. The advantage of this embodiment is that if the motor vehicle is stationary for a long time after starting, the motor vehicle may be subject to a collision. In this case, the reference signal is used to determine whether the motor vehicle is stationary for a long time after starting. Figure 4 and 5 The described method or method steps or their modifications may not be able to accurately determine whether the vehicle-mounted radar has an angular misalignment, but the radar still needs to be calibrated to improve the accuracy of the navigation system.

[0060] Although the specific embodiments of the present application are described in detail herein, they are provided only for the purpose of explanation and should not be considered to limit the scope of the present application. In addition, it should be clear to those skilled in the art that the various embodiments described in this specification can be used in combination with each other. Various replacements, changes and modifications can be conceived without departing from the spirit and scope of the present application.

Claims

1. A method for determining whether an on-vehicle radar has an angle misalignment, comprising: Determine an angle of a target in a point cloud generated by a radar (R) relative to a normal direction (RN) of the radar (R), wherein the angle comprises a horizontal angle and a vertical angle; Performing fast filtering on the horizontal angle or the vertical angle to obtain a fast angle of the horizontal angle or a fast angle of the vertical angle; The following first sub-process is performed for the fast angle of the horizontal angle or the vertical angle, and the first sub-process includes the following steps: 1) Calculate the variance and standard deviation of the fast angles of all horizontal angles or vertical angles in the time domain window (LT) with the current time as the end time; 2) If the variance is less than a non-zero positive integer multiple of the standard deviation, then execute the second sub-process for the horizontal angle or the vertical angle; otherwise, execute step 1) for the next moment; The second sub-process for horizontal angle or vertical angle includes the following steps: 3) performing slow filtering on the horizontal angle or the vertical angle to obtain a slow angle of the horizontal angle or a slow angle of the vertical angle; 4) If the slow angle of the horizontal angle or the slow angle of the vertical angle exceeds a predetermined limit value for the slow angle of the horizontal angle or the slow angle of the vertical angle, the current slow angle is updated to the predetermined limit value for the slow angle of the horizontal angle or the slow angle of the vertical angle; otherwise, continue to execute step 3) for the next moment; 5) If the fast angle of the horizontal angle or the fast angle of the vertical angle exceeds a predetermined limit, it is determined that there is an angle misalignment in the vehicle-mounted radar and an alarm is issued to calibrate the radar.

2. The method according to claim 1, characterized in that The first sub-process for the fast angle of the horizontal angle is synchronously executed with the first sub-process for the fast angle of the vertical angle; and / or the second sub-process for the horizontal angle is synchronously executed with the second sub-process for the vertical angle.

3. The method according to claim 2, characterized in that In the second subprocess, the non-zero positive integer multiple of the standard deviation is three times the standard deviation.

4. The method according to any one of claims 1 to 3, characterized in that: In the first sub-process, the second sub-process is performed only when the number of times that the variance is determined to be smaller than a non-zero positive integer multiple of the standard deviation reaches a predetermined threshold.

5. The method according to claim 4, characterized in that In the first sub-process, the predetermined threshold value for the horizontal angle is an integer between 2 and 100; and the predetermined threshold value for the vertical angle is an integer between 2 and 100.

6. The method according to claim 5, characterized in that In the first sub-process, when the variance is calculated for the horizontal angle, the expected value for the horizontal angle is ±5.7°; and when the variance is calculated for the vertical angle, the expected value for the vertical angle is ±6.3°.

7. The method according to claim 6, characterized in that In the second sub-process, the predetermined limit value for the horizontal angle is the same as the expected value for the horizontal angle; and / or the predetermined limit value for the vertical angle is the same as the expected value for the vertical angle.

8. The method according to claim 7, characterized in that After an alarm is issued to perform calibration on the radar, the counter is reset to zero, and the first sub-process for the fast angle for the horizontal angle and / or the fast angle for the vertical angle is performed again.

9. The method according to claim 8, characterized in that Independently of the execution of the first sub-process and / or the second sub-process, if the motor vehicle is detected to be stationary for more than a predetermined time, it is determined that there is an angular misalignment of the on-board radar and an alarm is issued to calibrate the radar.

10. The method according to any one of claims 1 to 9, characterized in that: The vehicle-mounted radar is a vehicle-used forward radar or a corner radar.

11. A vehicle-mounted domain controller, configured to be connected to vehicle-mounted radar data and to execute the steps of the method according to any one of claims 1 to 10.

12. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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