Preprocessing method and device for ranging value of ultrasonic radar

Abstract

The invention provides a preprocessing method and device for a ranging value of an ultrasonic radar, and the method comprises the steps: filtering a plurality of frames of original ranging values outputted by the ultrasonic radar carried by a target vehicle, and determining a to-be-processed original ranging value which is collected at present; correcting the original distance measurement value to be processed by using the obstacle point information to obtain a corrected distance measurement value; and outputting the corrected distance measurement value as an actual distance measurement value output at the current moment, or outputting a reckoning value as the actual distance measurement value output at the current moment. According to the scheme, the original ranging value is filtered and corrected, then the reckoning value or the corrected ranging value is output, the situation that the original ranging value is misreported due to complexity and uncertainty of an actual environment is avoided, and the false alarm rate of the ranging value is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic parking, and in particular to a preprocessing method and device for ranging values ​​of ultrasonic radar. Background Art

[0002] With the development of the automotive industry, many vehicles are now equipped with ultrasonic radars, which are used to measure the distance between vehicles and obstacles.

[0003] Currently, the echo is processed at the front end of the ultrasonic radar. However, due to the complexity and uncertainty of the actual environment, the front end cannot fully handle all working conditions, and the original ranging value output still has false alarms, and the false alarm rate of the ranging value is high. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a method and device for preprocessing the ranging value of an ultrasonic radar, so as to solve the problem of a high false alarm rate of the ranging value existing in the method of processing the echo at the front end of the ultrasonic radar.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] A first aspect of an embodiment of the present invention discloses a preprocessing method for a ranging value of an ultrasonic radar, the method comprising:

[0007] Filter multiple frames of raw ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the raw ranging value to be processed currently adopted;

[0008] Using the obstacle point information to correct the original distance measurement value to be processed to obtain a corrected distance measurement value;

[0009] The corrected distance measurement value is output as the actual distance measurement value output at the current moment, or the estimated value is output as the actual distance measurement value output at the current moment.

[0010] Preferably, filtering multiple frames of original ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the currently adopted original ranging value to be processed includes:

[0011] For each frame of raw ranging value output by the ultrasonic radar carried by the target vehicle, a timestamp check is performed on the raw ranging value according to the timestamp information of the ultrasonic radar, and a self-transmitted and received verification is performed on the raw ranging value according to the self-transmitted and received ranging value;

[0012] If the original ranging value passes the timestamp check and the self-transmitted and received check, it is determined that the original ranging value is a valid update;

[0013] When the original distance measurement value is effectively updated through multiple consecutive frames, the original distance measurement value of the current frame is determined as the currently adopted original distance measurement value to be processed.

[0014] Preferably, when the original ranging value is effectively updated for multiple consecutive frames, determining the original ranging value of the current frame as the currently adopted original ranging value to be processed includes:

[0015] Determining the relative motion state between the target vehicle and the obstacle;

[0016] If the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a first threshold or a second threshold, when the original ranging value is effectively updated after N or M consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed, wherein N is greater than M;

[0017] If the relative motion state is a stationary state or a moving away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a third threshold, when the original ranging value is effectively updated after N consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed.

[0018] Preferably, the original distance measurement value to be processed is corrected by using the obstacle point information to obtain a corrected distance measurement value, including:

[0019] Obtaining obstacle point information corresponding to a plurality of obstacle points to be filtered, wherein the obstacle point information at least includes obstacle point coordinates, and the plurality of obstacle points to be filtered at least include: triangulated positioning points output by the ultrasonic radar, and obstacle points detected by a camera of the target vehicle;

[0020] According to the obstacle point coordinates in the obstacle point information and the size of the target vehicle, identifying the valid obstacle points to be filtered;

[0021] Determine the effective obstacle point to be filtered that is closest to the target vehicle as the target obstacle point;

[0022] The obstacle point coordinates of the target obstacle point are used to correct the original distance measurement value to be processed to obtain a corrected distance measurement value.

[0023] Preferably, the obstacle point coordinates of the target obstacle point are used to correct the original distance measurement value to be processed to obtain a corrected distance measurement value, including:

[0024] Determine the radar partition where the target obstacle point is located by using the y-axis coordinate of the target obstacle point and the installation position of the ultrasonic radar;

[0025] Based on the x-axis coordinate of the target obstacle point, calculating the x-axis coordinate of the target obstacle point relative to the front of the target vehicle;

[0026] The minimum value of the following two is taken as the corrected ranging value: the x-axis coordinate of the target obstacle point relative to the front of the target vehicle, and the filtered original ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located.

[0027] Preferably, outputting the corrected ranging value as the actual ranging value output at the current moment, or outputting the estimated value as the actual ranging value output at the current moment, comprises:

[0028] Determining whether to output a calculated value based on the actual distance measurement value output at the last moment and the corrected distance measurement value;

[0029] If the estimated value is output, the distance measurement value is estimated according to the speed information of the target vehicle to obtain the estimated value, and the estimated value is output as the actual distance measurement value output at the current moment;

[0030] If the estimated value is not output, the corrected distance value is output as the actual distance value output at the current moment.

[0031] A second aspect of an embodiment of the present invention discloses a preprocessing device for a ranging value of an ultrasonic radar, the device comprising:

[0032] A filtering unit, used to filter multiple frames of raw ranging values ​​output by the ultrasonic radar carried by the target vehicle, and determine the raw ranging value to be processed that is currently adopted;

[0033] A correction unit, used to correct the original distance measurement value to be processed by using the obstacle point information to obtain a corrected distance measurement value;

[0034] The output unit is used to output the corrected distance measurement value as the actual distance measurement value output at the current moment, or to output the estimated value as the actual distance measurement value output at the current moment.

[0035] Preferably, the filtering unit comprises:

[0036] A verification module, for performing a timestamp verification on each frame of original ranging value output by the ultrasonic radar carried by the target vehicle according to the timestamp information of the ultrasonic radar, and performing a self-transmitted and received verification on the original ranging value according to the self-transmitted and received ranging value;

[0037] A first determination module, configured to determine that the original ranging value is a valid update if the original ranging value passes the timestamp check and the self-transmitted and received check;

[0038] The second determining module is used to determine the original ranging value of the current frame as the currently adopted original ranging value to be processed when the original ranging value is effectively updated through multiple consecutive frames.

[0039] Preferably, the second determining module is specifically used for:

[0040] Determining the relative motion state between the target vehicle and the obstacle;

[0041] If the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a first threshold or a second threshold, when the original ranging value is effectively updated after N or M consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed, wherein N is greater than M;

[0042] If the relative motion state is a stationary state or a moving away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a third threshold, when the original ranging value is effectively updated after N consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed.

[0043] Preferably, the correction unit comprises:

[0044] An acquisition module is used to acquire obstacle point information corresponding to a plurality of obstacle points to be filtered, wherein the obstacle point information at least includes obstacle point coordinates, and the plurality of obstacle points to be filtered at least include: triangulated positioning points output by the ultrasonic radar, and obstacle points detected by a camera of the target vehicle;

[0045] An identification module, used for identifying the effective obstacle points to be filtered according to the obstacle point coordinates in the obstacle point information and the size of the target vehicle;

[0046] A determination module, used to determine the effective obstacle point to be filtered that is closest to the target vehicle as the target obstacle point;

[0047] The correction module is used to correct the original distance measurement value to be processed by using the obstacle point coordinates of the target obstacle point to obtain a corrected distance measurement value.

[0048] Based on the above-mentioned embodiment of the present invention, a preprocessing method and device for the range value of ultrasonic radar is provided. The method is as follows: filtering the multiple frames of original range values ​​output by the ultrasonic radar carried by the target vehicle to determine the currently adopted original range value to be processed; using the obstacle point information to correct the original range value to be processed to obtain the corrected range value; outputting the corrected range value as the actual range value output at the current moment, or outputting the estimated value as the actual range value output at the current moment. In this scheme, the multiple frames of original range values ​​output by the ultrasonic radar are first filtered to determine the currently adopted original range value to be processed. The obstacle point information is used to correct the original range value to be processed to obtain the corrected range value, and the estimated value or the corrected range value is output as the actual range value output at the current moment. The original range value is first filtered and corrected, and then the estimated value or the corrected range value is output, so as to avoid the situation of false alarm of the original range value due to the complexity and uncertainty of the actual environment, and reduce the false alarm rate of the range value. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0050] Figure 1 A flowchart of a method for preprocessing ranging values ​​of an ultrasonic radar provided by an embodiment of the present invention;

[0051] Figure 2 An example diagram of the architecture of a state machine provided in an embodiment of the present invention;

[0052] Figure 3 An example diagram of the overall process of a preprocessing method for ranging values ​​of an ultrasonic radar provided in an embodiment of the present invention;

[0053] Figure 4 An example diagram of a process for filtering raw ranging values ​​provided in an embodiment of the present invention;

[0054] Figure 5 An example diagram of a process for obtaining a corrected ranging value provided by an embodiment of the present invention;

[0055] Figure 6 A structural block diagram of a preprocessing device for ranging values ​​of an ultrasonic radar provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] In this application, the terms "comprises", "comprising" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0058] With the development of the automotive industry, many vehicles are now equipped with ultrasonic radars to measure the distance between the vehicle and obstacles. For ultrasonic radars, the commonly used preprocessing methods are as follows:

[0059] The first existing preprocessing method is to judge the echo type according to the received echo data, determine the interference level of the interference echo, and adjust the time interval of the next detection cycle accordingly, so as to comprehensively judge whether there are obstacles in the detection area.

[0060] The second existing pre-processing method: determining whether a close-range echo is an interference echo during the echo processing stage.

[0061] The third existing pre-processing method is to filter out the interference of ground echo based on echo strength.

[0062] For the above-mentioned various existing preprocessing methods, the echo is processed at the front end of the ultrasonic radar. However, due to the complexity and uncertainty of the actual environment, the front end cannot fully handle all working conditions, and the output original ranging value still has false alarms, and the false alarm rate of the ranging value is high.

[0063] The inventor has found through research that when using ultrasonic radar at the back end, the original distance measurement value output by the ultrasonic radar needs to be preprocessed; in addition, the ultrasonic radar system generally includes multiple ultrasonic radars and uses a round-robin wave transmission method. A single ultrasonic radar is in a non-working state, so when necessary, it is estimated to enable the vehicle to continuously obtain the distance information of obstacles during movement, and adjust the driving strategy in real time according to the distance information to avoid collision with obstacles. On this basis, this scheme proposes a preprocessing method and device for the distance measurement value of ultrasonic radar, which first filters and corrects the original distance measurement value, and then outputs the estimated value or the corrected distance measurement value, so as to avoid the situation of false alarm of the original distance measurement value due to the complexity and uncertainty of the actual environment, and reduce the false alarm rate of the distance measurement value.

[0064] See also Figure 1 , shows a flow chart of a preprocessing method for a ranging value of an ultrasonic radar provided by an embodiment of the present invention, the preprocessing method comprising:

[0065] Step S101: filtering multiple frames of original ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the currently adopted original ranging value to be processed.

[0066] In the specific implementation of step S101, multiple frames of original ranging values ​​output by the ultrasonic radar carried by the target vehicle are obtained, and the obtained multiple frames of original ranging values ​​are filtered to determine the currently credible original ranging values ​​to be processed.

[0067] In some embodiments, the specific method of determining the currently adopted raw ranging value to be processed is: for each frame of raw ranging value output by the ultrasonic radar carried by the target vehicle, a timestamp check is performed on the raw ranging value according to the timestamp information of the ultrasonic radar, and a self-transmitted and received ranging value is performed on the raw ranging value according to the self-transmitted and received ranging value; if the raw ranging value passes the timestamp check and the self-transmitted and received ranging value, it is determined that the raw ranging value is effectively updated;

[0068] When the original distance measurement value is effectively updated through multiple consecutive frames, the original distance measurement value of the current frame is determined to be the currently adopted original distance measurement value to be processed.

[0069] To better understand how to perform timestamp verification and spontaneous reception verification on the original ranging value, an example is given to illustrate how to perform timestamp verification and spontaneous reception verification on the original ranging value of the current frame (or the original ranging value at the current moment).

[0070] The specific method of timestamp verification of the original ranging value of the current frame is as follows: if the timestamp information and the original ranging value of the current frame are both updated (the timestamp information and the original ranging value of the current frame are different from those of the previous frame), the original ranging value of the current frame is considered to have passed the timestamp verification (equivalent to the original ranging value of the current frame being valid); in addition, in order to avoid occasional asynchronous jumps between the timestamp information and the original ranging value, this scheme sets a window time (that is, a preset time threshold). If the duration of the timestamp information of the current frame remaining unchanged reaches the window time, the original ranging value of the current frame is also considered to have passed the timestamp verification.

[0071] Among them, when the original ranging value of the current frame passes the timestamp check, the corresponding valid flag bit will be output (the flag bit is true); the corresponding valid flag bit of the original ranging value of the current frame (that is, the timestamp check valid flag bit) indicates that the original ranging value of the current frame passes the timestamp check.

[0072] It should be noted that a vehicle is generally equipped with multiple ultrasonic radars. When an ultrasonic radar emits an ultrasonic wave, other ultrasonic radars installed adjacent to the ultrasonic radar will also receive an echo. The ranging value calculated by other ultrasonic radars through the echo is called the spontaneous and heterodyne ranging value. In other words, after an ultrasonic radar receives the echo corresponding to the ultrasonic wave emitted by an adjacent ultrasonic radar, the ranging value calculated based on the echo is the spontaneous and heterodyne ranging value.

[0073] The specific method of performing the self-transmitted other-received verification on the original ranging value of the current frame is as follows: verify whether the jump of the original ranging value of the current frame is valid according to the self-transmitted other-received ranging value; specifically, if the original ranging value of the current frame has a larger downward jump than the original ranging value of the previous frame (the downward jump exceeds a specified threshold), and the self-transmitted other-received ranging value of the current frame has a smaller downward jump than the self-transmitted other-received ranging value of the previous frame (the downward jump is less than a specified threshold), then the jump is considered invalid, that is, the original ranging value of the current frame has not passed the self-transmitted other-received verification; otherwise, it is considered that the original ranging value of the current frame has passed the self-transmitted other-received verification.

[0074] Among them, when the original ranging value of the current frame passes the autonomous reception verification, the corresponding autonomous reception verification flag will be output (the flag is true); the autonomous reception verification flag corresponding to the original ranging value of the current frame indicates that the original ranging value of the current frame has passed the autonomous reception verification.

[0075] The above is an example of performing timestamp verification and spontaneous reception verification on the original ranging value of the current frame; for each frame of original ranging value, when the valid flag bit (that is, the timestamp verification valid flag bit) and the spontaneous reception verification flag bit corresponding to the original ranging value of the frame are output, it indicates that the original ranging value of the frame is effectively updated.

[0076] The above content is used to determine whether the original ranging value output by the ultrasonic radar is a valid update, and the original ranging value is filtered according to the frame number of the valid updated original ranging value, so as to determine the currently adopted original ranging value to be processed.

[0077] In some embodiments, the specific method of determining the currently adopted raw distance measurement value to be processed is: determining the relative motion state between the target vehicle and the obstacle;

[0078] If the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the first threshold or the second threshold, when the original ranging value is effectively updated after continuous N or M frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed, wherein N is greater than M, one of the preferred example values ​​of N is 3, and correspondingly, one of the preferred example values ​​of M is 2.

[0079] Specifically, in one case, if the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the first threshold, when the original ranging value is continuously updated N times, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed;

[0080] In another case, if the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the second threshold, when the original ranging value is continuously updated M times, the original ranging value of the current frame is determined to be the currently adopted original ranging value to be processed.

[0081] It should be noted that, if the relative motion state is a close state, the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the first threshold value specifically means that: "the original ranging value of the current frame" is less than the first threshold value of "the original ranging value of the previous frame";

[0082] If the relative motion state is the approaching state, the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the second threshold, which specifically means that "the original ranging value of the current frame" is less than the second threshold of "the original ranging value of the previous frame".

[0083] If the relative motion state is a stationary state or a moving away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the third threshold, when the original ranging value is effectively updated after N consecutive frames, the original ranging value of the current frame is determined to be the currently adopted original ranging value to be processed.

[0084] It should be noted that, if the relative motion state is a stationary state or a far-away state, the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the third threshold, which specifically means that "the original ranging value of the current frame" is greater than the third threshold of "the original ranging value of the previous frame".

[0085] According to the moving direction of the target vehicle, the relative motion relationship between the target vehicle and the obstacle is divided into the following two types: approaching state and stationary state / faraway state.

[0086] In the approaching state, when the target vehicle is far away from the obstacle, if the original ranging value of the current frame is less than the first threshold of the original ranging value of the previous frame (equivalent to the original ranging value of the current frame having a larger jump than the original ranging value of the previous frame, that is, the jump amount is greater than the first threshold), then the original ranging value needs to pass through N frames before it is accepted; when the target vehicle is close to the obstacle, if the original ranging value of the current frame is less than the second threshold of the original ranging value of the previous frame (also equivalent to the original ranging value having a larger jump, that is, the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the second threshold), then the original ranging value needs to pass through M before it is accepted.

[0087] It is worth noting that in the approaching state, there are two situations, "the target vehicle is far away from the obstacle" and "the target vehicle is close to the obstacle". In these two situations, the first threshold and the second threshold used for judging "large jump of the original ranging value" are different; the second threshold used in the situation of "the target vehicle is close to the obstacle" is smaller than the first threshold used in the situation of "the target vehicle is far away from the obstacle", which can reduce the impact of ultrasonic false alarms at close distances.

[0088] In the stationary state / far away state, the collision risk of the target vehicle is considered to be small. If the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the third threshold (equivalent to the original ranging value of the current frame having a larger jump than the original ranging value of the previous frame), the original ranging value will not be adopted until N frames have passed.

[0089] Step S102: using the obstacle point information to correct the original distance measurement value to be processed, to obtain a corrected distance measurement value.

[0090] In the specific implementation of step S102, after the original distance measurement value to be processed (equivalent to the filtered original distance measurement value) is obtained, the original distance measurement value to be processed is corrected using the obstacle point information to obtain a corrected distance measurement value; wherein the obstacle point information at least includes the obstacle point coordinates (x-axis coordinates and y-axis coordinates).

[0091] It should be noted that the target vehicle is equipped with an ultrasonic radar system, which, in addition to outputting the original ranging values ​​of each ultrasonic radar, also outputs the front / rear triangulation positioning points. The triangulation positioning points are used as obstacle points to be filtered in subsequent content to correct the original ranging values ​​to be processed. In addition, the target vehicle is equipped with a camera, and the visual information output by the camera also includes the detected obstacle point positions (also called obstacle positions). The obstacle points detected by the camera are used as obstacle points to be filtered in subsequent content to correct the original ranging values ​​to be processed.

[0092] In some embodiments, the specific method of correcting the original ranging value to be processed to obtain the corrected ranging value is: obtaining obstacle point information corresponding to multiple obstacle points to be filtered, and the multiple obstacle points to be filtered at least include: triangulation positioning points output by ultrasonic radar, and obstacle points detected by the camera of the target vehicle; identifying valid obstacle points to be filtered according to the obstacle point coordinates in the obstacle point information and the size of the target vehicle; determining the valid obstacle point to be filtered that is closest to the target vehicle as the target obstacle point; and using the obstacle point coordinates of the target obstacle point to correct the original ranging value to be processed to obtain the corrected ranging value.

[0093] Furthermore, the specific method of using the obstacle point coordinates of the target obstacle point to correct the original ranging value to be processed is: using the y-axis coordinate of the target obstacle point and the installation position of the ultrasonic radar, determine the radar partition where the target obstacle point is located; based on the x-axis coordinate of the target obstacle point, calculate the x-axis coordinate of the target obstacle point relative to the front of the target vehicle; take the minimum value of the following two as the corrected ranging value: the x-axis coordinate of the target obstacle point relative to the front of the target vehicle, and the filtered original ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located.

[0094] To better explain how to determine the corrected distance measurement value, the following process A1-A5 is used as an example.

[0095] It should be noted that the target vehicle is a vehicle that supports automatic parking; the target vehicle is equipped with a camera, through which the marked parking space can be identified; the visual information output by the camera also includes the detected obstacle point positions; therefore, the obstacle points to be filtered in the following example include: triangulation positioning points, and obstacle points detected by the camera.

[0096] A1. According to the obstacle point coordinates of the obstacle point to be filtered and the body size of the target vehicle, determine whether each obstacle point to be filtered is valid.

[0097] For example: for the front ultrasonic radar system, if the x-coordinate of the obstacle point to be filtered is smaller than the front position of the target vehicle, or if the y-coordinate of the obstacle point to be filtered is larger than half the body width of the target vehicle, then the obstacle point to be filtered is considered invalid (an invalid point and will not be accepted); otherwise, the obstacle point to be filtered is determined to be valid.

[0098] A2. For the identified valid obstacle points to be filtered, sort the valid obstacle points to be filtered from small to large according to the x-coordinate, and determine the valid obstacle point to be filtered with the smallest x-coordinate as the target obstacle point. The target obstacle point is the valid obstacle point to be filtered that is closest to the target vehicle.

[0099] A3. Four ultrasonic radars are installed at the front / rear of the target vehicle. The lateral area of ​​the front of the target vehicle is evenly divided into four radar partitions according to the installation positions of the four ultrasonic radars installed at the front. The same applies to the rear of the target vehicle. According to the y-axis coordinate of the target obstacle point and the installation position of the ultrasonic radar, determine which radar partition the target obstacle point is in, and then correct the unprocessed raw ranging value of the ultrasonic radar corresponding to the radar partition where the target obstacle point is located.

[0100] In other words, the purpose of "determining in which radar zone the target obstacle point is located" is: after determining in which radar zone the target obstacle point is located, it is possible to confirm which ultrasonic radar output's filtered raw ranging value to be processed needs to be corrected.

[0101] A4. Based on the x-axis coordinate of the target obstacle point, calculate the x-axis coordinate of the target obstacle point relative to the front of the target vehicle; specifically, the base coordinate system of the target obstacle point is the vehicle coordinate system of the target vehicle, and the origin is the center of the rear axle of the target vehicle; therefore, the x-axis coordinate of the target obstacle point relative to the front of the target vehicle can be obtained by subtracting the longitudinal distance from the front of the target vehicle to the center of the rear axle from the x-axis coordinate of the target obstacle point.

[0102] A5. Determine the size of the x-axis coordinate of the target obstacle point relative to the front of the target vehicle and the filtered raw ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located, and output the smaller value of "the x-axis coordinate of the target obstacle point relative to the front of the target vehicle" and "the filtered raw ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located" as the corrected ranging value.

[0103] Step S103: outputting the corrected distance measurement value as the actual distance measurement value output at the current moment, or outputting the estimated value as the actual distance measurement value output at the current moment.

[0104] In the specific implementation of step S103, after determining that the corrected distance measurement value is obtained, the inferential state is judged according to the actual distance measurement value output at the last moment (that is, the distance value output to the automatic parking function module at the last moment) and the corrected distance measurement value, thereby determining whether to output the estimated value.

[0105] In some embodiments, the specific method of outputting the actual ranging value at the current moment is: judging whether to output the estimated value based on the actual ranging value output at the previous moment and the corrected ranging value; if the estimated value is output, the ranging value is estimated based on the speed information of the target vehicle to obtain the estimated value, and the estimated value is output as the actual ranging value output at the current moment; if the estimated value is not output, the corrected ranging value is output as the actual ranging value output at the current moment.

[0106] It should be noted that, considering the different obstacle collision risks at different distances during the automatic parking process of the target vehicle, and the relatively complex processing logic; this solution builds a state machine, the architecture of which is as follows Figure 2 shown.

[0107] Figure 2 The input of the state machine shown is the actual distance measurement value output at the previous moment, the corrected distance measurement value, the gear information, and the function status flag. The output of the state machine is the pushable status flag. Among them, the state machine includes four states: Far, Near, Risk, and Blind. The four states of Far, Near, Risk, and Blind correspond to the process of obstacles moving from far to near.

[0108] It should be noted that the function status flag of the above-mentioned input state machine refers to: a flag used to reflect the status of the automatic parking function; when the function status flag is true, it indicates that the automatic parking function is activated, and when the function status flag is false, it indicates that the automatic parking function is not activated.

[0109] When the inferable state flag bit output by the state machine is true, the inferred value is calculated and output as the actual distance measurement value output at the current moment; when the inferable state flag bit output by the state machine is false, the corrected distance measurement value is output as the actual distance measurement value output at the current moment.

[0110] In some embodiments, the specific method of calculating the distance measurement value according to the speed information of the target vehicle to obtain the estimated value is: the distance traveled by the target vehicle is calculated in real time according to the speed information and time, and the actual distance measurement value output at the previous moment is subtracted from the distance traveled by the target vehicle obtained by the above calculation to obtain the estimated value.

[0111] It should be noted that the ultrasonic radar system emits waves in a cycle when working, so the ultrasonic radar system is in a non-working state. At the same time, due to the complex actual environment, the ultrasonic radar may have false alarms. Therefore, it is necessary to make an inference based on the actual ranging value output at the previous moment, so that the target vehicle can continuously obtain the obstacle position during the movement, and then activate the corresponding algorithm logic according to the relative distance to the obstacle to reduce the risk of collision.

[0112] In addition, the estimated value may have limitations such as easy misactivation in certain scenarios. Therefore, this solution introduces a state machine to determine whether the actual distance measurement value output at the current moment is the estimated value or the corrected distance measurement value.

[0113] It should be further explained that when calculating the estimated value, this solution introduces the parking aid module (PAM) alarm information. Since the distance corresponding to the output value of the PAM system is within a certain range (the output value of the PAM is equivalent to the alarm level), in the process of calculating the estimated value, this solution sets the initial value of the estimated value at the current moment to the upper limit of the distance range corresponding to the PAM alarm level. This can improve the calculation efficiency and thereby improve the accuracy of the estimated value.

[0114] By using the state machine mentioned above, it is determined to output the corrected ranging value as the actual ranging value output at the current moment, or to output the estimated value as the actual ranging value output at the current moment; the actual ranging value at the current moment is output to the automatic parking function module of the target vehicle, so that the automatic parking function module plans a driving path without collision risk according to the actual ranging value.

[0115] In the embodiment of the present invention, the multiple frames of raw ranging values ​​output by the ultrasonic radar are first filtered to determine the raw ranging values ​​to be processed that are currently adopted. The raw ranging values ​​to be processed are corrected using obstacle point information to obtain the corrected ranging values, and the estimated values ​​or the corrected ranging values ​​are output as the actual ranging values ​​output at the current moment. The raw ranging values ​​are first filtered and corrected, and then the estimated values ​​or the corrected ranging values ​​are output, so as to avoid the situation where the raw ranging values ​​are falsely reported due to the complexity and uncertainty of the actual environment, and reduce the false alarm rate of the ranging values.

[0116] To better explain the above embodiments of the present invention Figure 1 The content in Figures 3 to 5 Give an example.

[0117] See also Figure 3 , shows an overall flow chart of a preprocessing method for the ranging value of an ultrasonic radar provided by an embodiment of the present invention. Overall, the preprocessing method includes the following steps:

[0118] S1: Filter the original distance measurement value and output the filtered value.

[0119] The output filtered value is the original distance measurement value to be processed.

[0120] S2: Use the obstacle point information to correct the original distance measurement value to be processed and output the corrected value.

[0121] The output correction value is the corrected distance measurement value.

[0122] S3: Pushable status judgment.

[0123] In the specific implementation, using Figure 2 The state machine shown obtains the pushable state flag.

[0124] S4: Vehicle speed compensation calculation.

[0125] In a specific implementation, the distance measurement value is estimated according to the speed information of the target vehicle to obtain an estimated value.

[0126] S5: Output the final distance measurement value.

[0127] The final distance measurement value outputted is the actual distance measurement value.

[0128] In a specific implementation, according to the inferable state flag, the corrected distance measurement value or the inferred value is output as the actual distance measurement value output at the current moment.

[0129] Regarding the above Figure 3 Step S1 in Figure 4 , which shows an example flow chart of filtering the original ranging value provided by an embodiment of the present invention, Figure 4 The following steps are involved:

[0130] S1-1: Using the self-transmitting and self-receiving ranging value ( Figure 4 The original distance measurement value is timestamped (also called validity check) and the valid flag is output.

[0131] It should be noted that the self-transmitted and self-received ranging value is: after a certain ultrasonic radar transmits ultrasonic waves, the ultrasonic radar calculates the ranging value based on the echo signal of the ultrasonic waves emitted by itself.

[0132] S1-2: Using the spontaneous receiving distance measurement value ( Figure 4 The original distance measurement value is referred to as the spontaneous reception value in the text), and the spontaneous reception check (also called jump check) is performed on the original distance measurement value; the spontaneous reception check flag bit is output ( Figure 4 It is referred to as the check flag in the text.

[0133] S1-3: Filter the original distance measurement value according to the valid flag, the spontaneous reception verification flag, the approaching state of the target vehicle, and the stationary / faraway state of the target vehicle.

[0134] Regarding the above Figure 3 Step S2 in Figure 5 , shows an example diagram of a process for obtaining a corrected ranging value provided by an embodiment of the present invention, Figure 5 The following steps are involved:

[0135] S2-1: Use the triangulated positioning points and the obstacle points detected by the camera to perform preprocessing to identify the nearest obstacle point, which is the target obstacle point.

[0136] The preprocessing in S2-1 includes the processing of "judging the validity of the obstacle points to be filtered" and "sorting the valid obstacle points to be filtered". The target obstacle point is the valid obstacle point to be filtered that is closest to the target vehicle.

[0137] S2-2: Confirm the radar zone where the target obstacle point is located.

[0138] S2-3: Take the minimum value correction ( Figure 5 In the figure, the small correction is taken to obtain the corrected distance value.

[0139] Among them, taking the minimum value correction specifically means: taking the smaller value of "the x-axis coordinate of the target obstacle point relative to the front of the target vehicle" and "the filtered raw ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located" as the corrected ranging value.

[0140] It should be noted that the above Figures 3 to 5 For the execution principle of each step in the embodiment of the present invention, please refer to the above embodiment of the present invention. Figure 1 The contents in will not be repeated here.

[0141] Combining the contents of the above embodiments, it can be seen that this solution has the following beneficial effects:

[0142] This solution is easy to implement and has a fast computation speed, which is conducive to real-time correction in the automatic parking planning process;

[0143] This solution has stable functions and intuitive performance, is less dependent on historical data, and can effectively solve the problem of ultrasonic false alarms caused by co-frequency interference, complex environment and other factors;

[0144] This scheme includes a judgment mechanism for the pushable status flag, which realizes the reasonable trade-off between the corrected ranging value and the estimated value at different distances, and improves the availability and reliability of the ultrasonic radar.

[0145] Corresponding to the preprocessing method for the ranging value of the ultrasonic radar provided in the above embodiment of the present invention, see Figure 6 , the embodiment of the present invention also provides a structural block diagram of a preprocessing device for the ranging value of an ultrasonic radar, the preprocessing device includes: a filtering unit 601, a correction unit 602, and an output unit 603;

[0146] The filtering unit 601 is used to filter multiple frames of original ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the currently adopted original ranging value to be processed.

[0147] The correction unit 602 is used to correct the original distance measurement value to be processed by using the obstacle point information to obtain a corrected distance measurement value.

[0148] The output unit 603 is used to output the corrected distance measurement value as the actual distance measurement value output at the current moment, or to output the estimated value as the actual distance measurement value output at the current moment.

[0149] In a specific implementation, the output unit 603 is specifically used to: determine whether to output a calculated value based on the actual distance measurement value output at the previous moment and the corrected distance measurement value; if the calculated value is output, the distance measurement value is calculated based on the speed information of the target vehicle to obtain the calculated value, and the calculated value is output as the actual distance measurement value output at the current moment; if the calculated value is not output, the corrected distance measurement value is output as the actual distance measurement value output at the current moment.

[0150] In the embodiment of the present invention, the multiple frames of raw ranging values ​​output by the ultrasonic radar are first filtered to determine the raw ranging values ​​to be processed that are currently adopted. The raw ranging values ​​to be processed are corrected using obstacle point information to obtain the corrected ranging values, and the estimated values ​​or the corrected ranging values ​​are output as the actual ranging values ​​output at the current moment. The raw ranging values ​​are first filtered and corrected, and then the estimated values ​​or the corrected ranging values ​​are output, so as to avoid the situation where the raw ranging values ​​are falsely reported due to the complexity and uncertainty of the actual environment, and reduce the false alarm rate of the ranging values.

[0151] Preferably, combined Figure 6 The content shown, the filtering unit 601 includes a verification module, a first determination module and a second determination module; the execution principle of each module is as follows:

[0152] The verification module is used to perform timestamp verification on each frame of the original ranging value output by the ultrasonic radar carried by the target vehicle according to the timestamp information of the ultrasonic radar, and to perform spontaneous reception verification on the original ranging value according to the spontaneous reception ranging value.

[0153] The first determination module is used to determine that the original ranging value is a valid update if the original ranging value passes the timestamp verification and the spontaneous transmission and reception verification.

[0154] The second determination module is used to determine the original ranging value of the current frame as the currently adopted original ranging value to be processed when the original ranging value is effectively updated through multiple consecutive frames.

[0155] In a specific implementation, the second determination module is specifically used to: determine the relative motion state of the target vehicle and the obstacle; if the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the first threshold or the second threshold, when the original ranging value is effectively updated after N or M consecutive frames, determine that the original ranging value of the current frame is the currently adopted original ranging value to be processed, where N is greater than M; if the relative motion state is a stationary state or a far away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than the third threshold, when the original ranging value is effectively updated after N consecutive frames, determine that the original ranging value of the current frame is the currently adopted original ranging value to be processed.

[0156] Preferably, combined Figure 6 The content shown, the correction unit 602 includes an acquisition module, an identification module, a determination module, and a correction module; the execution principle of each module is as follows:

[0157] The acquisition module is used to obtain obstacle point information corresponding to multiple obstacle points to be filtered, the obstacle point information at least includes the obstacle point coordinates, and the multiple obstacle points to be filtered at least include: triangulation positioning points output by the ultrasonic radar, and obstacle points detected by the camera of the target vehicle.

[0158] The identification module is used to identify effective obstacle points to be filtered according to the obstacle point coordinates and the size of the target vehicle in the obstacle point information.

[0159] The determination module is used to determine the effective obstacle point to be filtered that is closest to the target vehicle as the target obstacle point.

[0160] The correction module is used to correct the original distance measurement value to be processed by using the obstacle point coordinates of the target obstacle point to obtain a corrected distance measurement value.

[0161] In the specific implementation, the correction module is specifically used to: determine the radar partition where the target obstacle point is located by using the y-axis coordinate of the target obstacle point and the installation position of the ultrasonic radar; calculate the x-axis coordinate of the target obstacle point relative to the front of the target vehicle based on the x-axis coordinate of the target obstacle point; take the minimum value of the following two as the corrected ranging value: the x-axis coordinate of the target obstacle point relative to the front of the target vehicle, and the filtered original ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located.

[0162] In summary, the embodiment of the present invention provides a preprocessing method and device for the ranging value of the ultrasonic radar, which first filters the multiple frames of original ranging values ​​output by the ultrasonic radar to determine the currently adopted original ranging value to be processed. The original ranging value to be processed is corrected using obstacle point information to obtain a corrected ranging value, and an estimated value or a corrected ranging value is output as the actual ranging value output at the current moment. The original ranging value is first filtered and corrected, and then the estimated value or the corrected ranging value is output, so as to avoid the situation of misreporting the original ranging value due to the complexity and uncertainty of the actual environment, and reduce the false alarm rate of the ranging value.

[0163] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0164] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0165] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preprocessing method for the ranging value of ultrasonic radar, characterized in that: The method comprises: Filter multiple frames of raw ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the raw ranging value to be processed currently adopted; Using the obstacle point information to correct the original distance measurement value to be processed to obtain a corrected distance measurement value; The corrected distance measurement value is output as the actual distance measurement value output at the current moment, or the estimated value is output as the actual distance measurement value output at the current moment.

2. The method according to claim 1, characterized in that Filter the multiple frames of raw ranging values ​​output by the ultrasonic radar carried by the target vehicle to determine the currently adopted raw ranging values ​​to be processed, including: For each frame of raw ranging value output by the ultrasonic radar carried by the target vehicle, a timestamp check is performed on the raw ranging value according to the timestamp information of the ultrasonic radar, and a self-transmitted and received verification is performed on the raw ranging value according to the self-transmitted and received ranging value; If the original ranging value passes the timestamp check and the self-transmitted and received check, it is determined that the original ranging value is a valid update; When the original distance measurement value is effectively updated through multiple consecutive frames, the original distance measurement value of the current frame is determined as the currently adopted original distance measurement value to be processed.

3. The method according to claim 2, characterized in that When the original ranging value is effectively updated for multiple consecutive frames, determining the original ranging value of the current frame as the currently adopted original ranging value to be processed includes: Determining the relative motion state between the target vehicle and the obstacle; If the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a first threshold or a second threshold, when the original ranging value is effectively updated after N or M consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed, wherein N is greater than M; If the relative motion state is a stationary state or a moving away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a third threshold, when the original ranging value is effectively updated after N consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed.

4. The method according to claim 1, characterized in that: The original distance measurement value to be processed is corrected by using the obstacle point information to obtain a corrected distance measurement value, including: Obtaining obstacle point information corresponding to a plurality of obstacle points to be filtered, wherein the obstacle point information at least includes obstacle point coordinates, and the plurality of obstacle points to be filtered at least include: triangulated positioning points output by the ultrasonic radar, and obstacle points detected by a camera of the target vehicle; According to the obstacle point coordinates in the obstacle point information and the size of the target vehicle, identifying the valid obstacle points to be filtered; Determine the effective obstacle point to be filtered that is closest to the target vehicle as the target obstacle point; The obstacle point coordinates of the target obstacle point are used to correct the original distance measurement value to be processed to obtain a corrected distance measurement value.

5. The method according to claim 4, characterized in that The original distance measurement value to be processed is corrected using the obstacle point coordinates of the target obstacle point to obtain a corrected distance measurement value, including: Determine the radar partition where the target obstacle point is located by using the y-axis coordinate of the target obstacle point and the installation position of the ultrasonic radar; Based on the x-axis coordinate of the target obstacle point, calculating the x-axis coordinate of the target obstacle point relative to the front of the target vehicle; The minimum value of the following two is taken as the corrected ranging value: the x-axis coordinate of the target obstacle point relative to the front of the target vehicle, and the filtered original ranging value to be processed output by the ultrasonic radar corresponding to the radar partition where the target obstacle point is located.

6. The method according to claim 1, characterized in that Outputting the corrected ranging value as the actual ranging value output at the current moment, or outputting the estimated value as the actual ranging value output at the current moment, comprises: Determining whether to output a calculated value based on the actual distance measurement value output at the last moment and the corrected distance measurement value; If the estimated value is output, the distance measurement value is estimated according to the speed information of the target vehicle to obtain the estimated value, and the estimated value is output as the actual distance measurement value output at the current moment; If the estimated value is not output, the corrected distance value is output as the actual distance value output at the current moment.

7. A preprocessing device for ultrasonic radar ranging value, characterized in that: The device comprises: A filtering unit, used to filter multiple frames of raw ranging values ​​output by the ultrasonic radar carried by the target vehicle, and determine the raw ranging value to be processed that is currently adopted; A correction unit, used to correct the original distance measurement value to be processed by using the obstacle point information to obtain a corrected distance measurement value; The output unit is used to output the corrected distance measurement value as the actual distance measurement value output at the current moment, or to output the estimated value as the actual distance measurement value output at the current moment.

8. The device according to claim 7, characterized in that The filtering unit comprises: A verification module, for performing a timestamp verification on each frame of original ranging value output by the ultrasonic radar carried by the target vehicle according to the timestamp information of the ultrasonic radar, and performing a self-transmitted and received verification on the original ranging value according to the self-transmitted and received ranging value; A first determination module, configured to determine that the original ranging value is a valid update if the original ranging value passes the timestamp check and the self-transmitted and received check; The second determining module is used to determine the original ranging value of the current frame as the currently adopted original ranging value to be processed when the original ranging value is effectively updated through multiple consecutive frames.

9. The device according to claim 8, characterized in that The second determining module is specifically used for: Determining the relative motion state between the target vehicle and the obstacle; If the relative motion state is a close state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a first threshold or a second threshold, when the original ranging value is effectively updated after N or M consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed, wherein N is greater than M; If the relative motion state is a stationary state or a moving away state, and if the jump amount of the original ranging value of the current frame relative to the original ranging value of the previous frame is greater than a third threshold, when the original ranging value is effectively updated after N consecutive frames, it is determined that the original ranging value of the current frame is the currently adopted original ranging value to be processed.

10. The device according to claim 7, characterized in that The correction unit comprises: An acquisition module is used to acquire obstacle point information corresponding to a plurality of obstacle points to be filtered, wherein the obstacle point information at least includes obstacle point coordinates, and the plurality of obstacle points to be filtered at least include: triangulated positioning points output by the ultrasonic radar, and obstacle points detected by a camera of the target vehicle; An identification module, used for identifying the effective obstacle points to be filtered according to the obstacle point coordinates in the obstacle point information and the size of the target vehicle; A determination module, used to determine the effective obstacle point to be filtered that is closest to the target vehicle as the target obstacle point; The correction module is used to correct the original distance measurement value to be processed by using the obstacle point coordinates of the target obstacle point to obtain a corrected distance measurement value.

Images