A ranging method, apparatus, terminal device, and computer-readable storage medium

Abstract

The application is suitable for the field of radar technology, and provides a ranging method and device, a terminal equipment and a computer readable storage medium, comprising: extracting a signal feature of an original echo signal; determining a target ranging timing value according to the signal feature; and calculating the distance of a target object according to the target ranging timing value. The signal feature representing the autocorrelation degree of the signal intensity inside each signal segment is extracted, threshold detection is performed by using the signal feature, and then the target ranging timing value used for calculating the distance of the target object is calculated. The application can increase the detection distance of the laser radar in a low signal-to-noise ratio scene, and can improve the ranging performance of the laser radar in a long-distance detection scene.

Description

Technical Field

[0001] This application belongs to the field of radar technology, and in particular relates to a ranging method, terminal equipment and computer-readable storage medium. Background Technology

[0002] LiDAR is a detection device used to explore the space environment. Due to its advantages such as high resolution, high sensitivity, strong anti-interference ability, and unaffected by dark conditions, it is often used in many scenarios such as autonomous driving, intelligent public transportation, 3D modeling of buildings, and terrain mapping.

[0003] Assuming the transmitting and receiving modules are identical, as the distance between the lidar and the target object increases, the intensity of the echo signal returned by the target object will weaken, and the signal-to-noise ratio of the received echo signal will also be lower. Therefore, the lidar's ranging capability and ranging accuracy will also be worse.

[0004] Currently, the detection range of lidar is typically increased by either raising the peak power of the emitted laser or enlarging the aperture of the receiving lens. However, increasing the peak power of the emitted laser increases the performance loss of the lidar, increases the overall burden on the lidar equipment, and can damage the operator's eyesight by emitting lasers with excessively high peak power. On the other hand, increasing the aperture of the receiving lens increases the overall size and weight of the lidar, and because the aperture of the receiving lens is larger, it will receive more interference signals, which may also lead to a decrease in the signal-to-noise ratio of the received echo signal. Summary of the Invention

[0005] This application provides a ranging method, apparatus, terminal device, and computer-readable storage medium to address the problem of decreased detection performance of lidar in long-distance scenarios.

[0006] In a first aspect, embodiments of this application provide a ranging method, including:

[0007] Extract signal features from the original echo signal; the signal features are the autocorrelation degree of the signal intensity of each signal segment in the original echo signal;

[0008] Determine the target ranging timing value based on the signal characteristics;

[0009] The distance to the target object is calculated based on the target ranging time value.

[0010] In one implementation of the first aspect, the extraction of signal features of the original echo signal includes: (1) selecting a signal segment based on a sliding window; (2) calculating the signal feature value of the selected signal segment based on the short-time average autocorrelation function; and (3) traversing the original echo signal by a sliding window and outputting the signal feature curve of the original echo signal.

[0011] In one implementation of the first aspect, determining the target ranging timing value based on the signal characteristics includes: (1) traversing the signal characteristic curve to determine the rising edge trigger time of the signal characteristic curve; and (2) determining the rising edge trigger time as the target ranging timing value.

[0012] In one implementation of the first aspect, traversing the signal characteristic curve to determine the rising edge trigger time of the signal characteristic curve includes:

[0013] The starting position index of the signal feature curve is determined according to a first preset threshold. The starting position index is used for threshold detection. The starting position index is the index of the first position of the signal feature curve that is not greater than the first preset threshold.

[0014] Create a rising edge cache list and a falling edge cache column. The rising edge cache list is used to store the rising edge trigger time, and the falling edge trigger time is used to cache the falling edge trigger time.

[0015] Starting from the starting position index, traverse the signal feature curve. If the signal feature is greater than the first preset threshold and the rising edge buffer list length is equal to the falling edge buffer list length, then perform linear interpolation based on the current position index and the previous position index of the current position index to calculate the rising edge trigger time, and store the rising edge trigger time in the rising edge buffer list.

[0016] If the signal characteristic is less than the first preset threshold, and the length of the rising edge buffer list is 1 greater than the length of the falling edge buffer list, then linear interpolation is performed based on the current position index and the next position index of the current position index to calculate the falling edge trigger time.

[0017] If the time difference between the falling edge trigger time and the last rising edge trigger time in the rising edge cache list is greater than or equal to the first preset pulse width, then the falling edge trigger time is stored in the falling edge cache list; otherwise, the last rising edge trigger time in the rising edge cache list is deleted.

[0018] In one implementation of the first aspect, the extraction of signal features from the original echo signal includes:

[0019] Locate the zero-crossing segments of the original echo signal;

[0020] The zero-crossing segments of the original echo signal are filtered based on the continuous zero-crossing threshold.

[0021] Calculate the signal characteristics of the zero-crossing signal segments obtained by the screening.

[0022] In one implementation of the first aspect, determining the target ranging timing value based on the signal characteristics includes:

[0023] The rising edge trigger time is determined based on the signal characteristics of the zero-crossing signal segment;

[0024] The rising edge trigger time is determined as the target ranging timing value.

[0025] In one implementation of the first aspect, determining the rising edge trigger time based on the signal characteristics of the zero-crossing signal segment includes:

[0026] Determine whether the signal characteristics of the zero-crossing signal segment are greater than a first preset threshold;

[0027] If the signal characteristics of the zero-crossing signal segment are greater than the first preset threshold, then linear interpolation is performed based on the first zero-crossing index position of the zero-crossing segment and the index position preceding the first zero-crossing index position to calculate the rising edge trigger time.

[0028] Secondly, embodiments of this application provide a ranging device, comprising:

[0029] The feature extraction module is used to extract the signal features of the original echo signal; the signal features are the autocorrelation degree of the signal intensity of the signal segment;

[0030] A timing value determination module is used to determine the target ranging timing value based on the signal characteristics;

[0031] The distance calculation module is used to calculate the distance to the target object based on the target ranging time value.

[0032] Thirdly, embodiments of this application provide a terminal device, the terminal device including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the ranging method as described in the first aspect or any optional method of the first aspect.

[0033] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the ranging method as described in the first aspect or any alternative method of the first aspect.

[0034] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, causes the terminal device to execute the ranging method described in the first aspect or any optional method of the first aspect.

[0035] The beneficial effects of the embodiments in this application compared with the prior art are:

[0036] Implementing the ranging method, terminal device, computer-readable storage medium, and computer program product provided in this application has the following beneficial effects:

[0037] The ranging method provided in this application extracts signal features that can represent the correlation between signal strengths within each signal segment, and uses these signal features to determine the target ranging time value used to calculate the distance to the target object. This can increase the detection range of the lidar in low signal-to-noise ratio scenarios and improve the ranging performance of the lidar in long-range detection scenarios. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram illustrating the application scenarios of the time-of-flight method;

[0040] Figure 2 This is a schematic diagram illustrating the implementation process of a ranging method provided in an embodiment of this application;

[0041] Figure 3 This is a schematic diagram of the implementation process of S201 in the ranging method provided in the embodiments of this application;

[0042] Figure 4 This is a schematic diagram of the signal characteristic values ​​of each signal segment of the original echo signal in the embodiments of this application;

[0043] Figure 5 This is a schematic diagram of the implementation process of S202 in the ranging method provided in the embodiments of this application;

[0044] Figure 6 This is a schematic diagram of the implementation process of S201 in a ranging method provided in another embodiment of this application;

[0045] Figure 7 This is a schematic diagram of the structure of a ranging device provided in an embodiment of this application;

[0046] Figure 8 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0047] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0048] It should be understood that the term "and / or" as used in this application specification and the appended claims refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations. Furthermore, in the description of this application specification and the appended claims, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0049] It should also be understood that references to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include the specific features, structures, or characteristics described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0050] LiDAR (Light Detection and Ranging) is an automatic remote sensing device that uses a laser as the emission light source and employs photoelectric detection technology for detection. The working principle of LiDAR is to emit a detection laser towards the target object. After the detection laser hits the target object, the target object reflects the detection laser, forming an echo signal. The receiving array can receive this echo signal and process it to obtain information such as the target object's distance, size, speed, and reflectivity.

[0051] Time-of-flight (TOF) ranging is a commonly used method for distance measurement. It involves continuously sending laser beams towards a target object to detect it, then receiving the echo signal returned by a sensor. The distance between the lidar and the target object is calculated by multiplying half the round-trip time of the echo signal by the speed of light. Due to its simple principle and ease of implementation, TOF ranging is widely used in various distance measurement scenarios.

[0052] Please see Figure 1 , Figure 1A schematic diagram illustrating an application scenario of the time-of-flight method is shown. For example... Figure 1 As shown, the car 11 is equipped with a lidar 12. The lidar 12 emits a detection laser (continuously sending light pulse signals) towards the target object 13. After the detection laser hits the target object 13, the target object 13 will reflect an echo. The receiving device of the lidar 12 receives the echo signal reflected by the target object 13. By measuring the round-trip time τ of the detection light pulse signal, and then multiplying half of the round-trip time τ / 2 by the speed of light c, the distance of the target to be measured from the laser source can be obtained.

[0053] Since the signal strength of the received echo signal decreases as the distance between the lidar and the target object increases, the signal-to-noise ratio of the received echo signal also decreases, which affects the lidar's ranging capability, ranging accuracy, and other detection performance.

[0054] To address the issue of decreased detection performance of lidar in long-distance scenarios, this application provides a ranging method. By extracting signal features that represent the correlation between signal strengths within each signal segment, the method uses these signal features to determine target ranging time values ​​for calculating the distance to the target object. This increases the detection range of lidar in low signal-to-noise ratio scenarios and improves the ranging performance of lidar in long-distance detection scenarios.

[0055] The ranging method provided in the embodiments of this application will be described in detail below:

[0056] Please see Figure 2 , Figure 2 This is a flowchart illustrating a ranging method provided in an embodiment of this application. The executing entity of the ranging method provided in this application can be a lidar, the signal processing system within the lidar, or a terminal device communicating with the lidar. The aforementioned terminal device can be a mobile terminal such as a smartphone, tablet, or wearable device, or it can be a computer, cloud server, radar-assisted computer, or other devices used in various application scenarios. The following explanation uses a lidar as the executing entity as an example:

[0057] like Figure 2 As shown, the ranging method provided in this application embodiment may include S201 to S203, which are detailed below:

[0058] S201: Extract the signal characteristics of the original echo signal.

[0059] In this embodiment of the application, the above-mentioned signal characteristics refer to the correlation of the signal strengths of various signal segments in the original echo signal.

[0060] In one embodiment of this application, the short-time average autocorrelation function can be selected as the signal feature of each signal segment in the original echo signal.

[0061] It should be noted that other functions that can represent the correlation of signal strength of signal segments can also be used to calculate the signal characteristics of each signal segment, such as autocorrelation function, short-time autocorrelation function, cross-correlation function, etc. This application does not limit this.

[0062] Please see Figure 3 , Figure 3 This diagram illustrates the implementation flow of step S201 in a ranging method provided in an embodiment of this application. Figure 3 As shown, in this embodiment of the application, S201 may include the following steps:

[0063] S301: Select signal segments based on sliding window method.

[0064] In practical applications, a signal segment is selected using a preset window length threshold w, and this signal segment is denoted as S. t1:t1+w-1 .

[0065] It should be noted that, for ease of calculation, the preset window length w is selected as an odd number.

[0066] In practical applications, the preset window length threshold w can be set according to the pulse width of the emitted pulse signal of the lidar.

[0067] For example, the preset window length threshold w can be set to the pulse width of the transmitted pulse signal of the lidar; or, if the pulse width of the transmitted pulse signal of the lidar is an even number, the preset window length threshold w can be set to the pulse width of the transmitted pulse signal plus a certain preset length. Specifically, the preset width can be an odd number such as 1, 3, or 5, and this application does not limit it.

[0068] S302: Calculate the signal characteristic values ​​of the selected signal segment based on the short-time average autocorrelation function.

[0069] In practical applications, signal segment S is calculated based on the short-time average autocorrelation function. t1:t1+w-1 The signal characteristic value at the middle position The calculation formula is as follows:

[0070]

[0071] Where R(t) is the signal segment S t1:t1+w-1 The autocorrelation function can be expressed as:

[0072]

[0073] S303: Slide the window to traverse the original echo signal and obtain the signal characteristic curve corresponding to the original echo signal.

[0074] Please see Figure 4 , Figure 4 This illustration shows a schematic diagram of the signal characteristic values ​​of each signal segment of the original echo signal in an embodiment of this application. For example... Figure 4 As shown, the sliding window's step size can be set to 1, and the signal segment S can be obtained. t1:t1+w-1 The signal characteristic value at the middle position Then, the sliding window moves to the next moment, at which point it selects signal segment S. t2:t2+w-1 Then calculate signal segment S. t2:t2+w-1 The signal characteristic value at the middle position Signal feature values It was determined to be signal segment S t2:t2+w-1 The signal characteristic values ​​are obtained; the above operation is repeated until the original echo signal has been traversed. At this point, the signal characteristic values ​​of all signal segments are obtained, which is the signal characteristic curve corresponding to the original echo signal.

[0075] S202: Determine the target ranging timing value based on the signal characteristics.

[0076] In this embodiment of the application, once the signal characteristics of the original echo signal are determined, the target ranging time value can be determined based on the signal characteristic curve.

[0077] In practical applications, when the laser emitted by the lidar detects a target object, the target object reflects back an echo signal. When the laser emitted by the lidar detects multiple target objects, the original echo signal received by the lidar will contain multiple echo signals.

[0078] Please see Figure 5 , Figure 5 The diagram shows a schematic representation of the implementation process of step S202 in a ranging method provided in an embodiment of this application.

[0079] like Figure 5 As shown, when outputting the signal characteristic curve corresponding to the original echo signal based on the short-time average autocorrelation function, S202 may include the following steps:

[0080] S501: Traverse the signal characteristic curves to determine the rising edge trigger time of the signal characteristic curves.

[0081] In this embodiment of the application, the rising edge trigger time of the signal characteristic curve is the time when the target object reflects the echo signal. When the original echo signal contains multiple echo signals returned by multiple target objects, the obtained signal characteristic curve will include multiple rising edge trigger times.

[0082] For example, when the laser emitted by the lidar detects two objects (hereinafter referred to as the first target object and the second target object), the first target object will reflect a first echo signal and the second target object will reflect a second echo signal. At this time, the original echo signal received by the lidar includes the first echo signal and the second echo signal. Accordingly, the first rising edge trigger time corresponding to the first echo signal and the second rising edge trigger time corresponding to the second echo signal can be calculated according to the signal characteristic curve.

[0083] In this embodiment of the application, S501 may include the following steps:

[0084] The starting position index of the signal characteristic curve used for threshold detection is determined according to the first preset threshold.

[0085] Starting from the starting position index, traverse the signal feature curve. If the signal feature is greater than the first preset threshold and the rising edge buffer list length is equal to the falling edge buffer list length, then perform linear interpolation based on the current position index and the previous position index of the current position index to calculate the rising edge trigger time, and store the rising edge trigger time in the rising edge buffer list.

[0086] If the signal characteristic is less than the first preset threshold, and the length of the rising edge buffer list is 1 greater than the length of the falling edge buffer list, then linear interpolation is performed based on the current position index and the next position index of the current position index to calculate the falling edge trigger time.

[0087] If the time difference between the falling edge trigger time and the last rising edge trigger time in the rising edge cache list is greater than or equal to the first preset pulse width, then the falling edge trigger time is stored in the falling edge cache list; otherwise, the last rising edge trigger time in the rising edge cache list is deleted.

[0088] In practical applications, the aforementioned first preset threshold can be set according to the actual scenario and the performance of the LiDAR, and this application does not impose any restrictions on it.

[0089] In a specific application, determining the starting position index of the signal feature curve based on the first preset threshold means: starting from the beginning of the signal feature curve, traversing and finding the first time point where the signal feature value is not greater than the first preset threshold, and determining this time point as the starting position index of the signal feature curve.

[0090] In practical applications, a rising edge cache list and a falling edge cache list are first created. The rising edge cache list is used to store the found rising edge trigger times, and the falling edge cache list is used to store the found falling edge trigger times.

[0091] In practical applications, the next time t is indexed from the starting position t0. 0+1 The process begins by traversing the aforementioned signal characteristic curves, determining whether the signal characteristic value is greater than the first preset threshold. If the signal characteristic value is greater than the first preset threshold, the rising edge trigger time is found using linear interpolation, and then stored in the rising edge buffer list. Next, it continues to determine whether the signal characteristic value is less than the first preset threshold. If the signal characteristic value is less than the first preset threshold and the length of the rising edge buffer list is one greater than the length of the falling edge buffer list, the falling edge trigger time is found using linear interpolation. Finding one rising edge trigger time and one falling edge trigger time completes the detection of one echo. If the received original echo signal contains echo signals reflected from multiple target objects, multiple rising edge trigger times and multiple falling edge trigger times can be detected from the aforementioned signal characteristic curves.

[0092] The length of the rising edge cache list refers to the number of rising edge trigger moments contained in the rising edge cache list, and the length of the falling edge cache list refers to the number of falling edge trigger moments contained in the falling edge cache list.

[0093] After finding each falling edge trigger moment, it is necessary to first determine whether the time difference between the found falling edge trigger moment and the last rising edge trigger moment in the rising edge buffer list is greater than or equal to the first preset pulse width. Only if the time difference between the found falling edge trigger moment and the last rising edge trigger moment in the rising edge buffer list is the found falling edge trigger moment stored in the falling edge buffer list. If the time difference between the found falling edge trigger moment and the last rising edge trigger moment in the rising edge buffer list is less than the first preset pulse width, the signal segment corresponding to the found rising edge trigger moment and falling edge trigger moment is identified as an interference signal. At this time, the last rising edge trigger moment is deleted from the rising edge buffer list. This can effectively avoid interference from interference signals and improve the detection accuracy.

[0094] It should be noted that the first preset pulse width can be set according to the pulse width of the interference signal present in the application scenario of the lidar, and this application does not impose any restrictions on it.

[0095] S502: The rising edge trigger time is determined as the target ranging timing value.

[0096] In practical applications, the target ranging timing value is determined by the rising edge trigger times stored in the rising edge cache list. If multiple rising edge trigger times exist in the rising edge cache list, each rising edge trigger time is determined as the target ranging timing value for its corresponding target object.

[0097] For example, suppose a lidar emits a laser and detects two target objects (a first target object and a second target object). The first target object will reflect a first echo signal, and the second target object will reflect a second echo signal. Since there is a time difference between when the laser detects the first and second target objects, the lidar will receive two echo signals: the first echo signal reflected by the first target object and the second echo signal reflected by the second target object. Therefore, the signal characteristic curve corresponding to the original echo signal has two rising edge trigger times, meaning there are two rising edge trigger times in the rising edge buffer list. Assuming the laser detects the first target object first, the first rising edge trigger time in the rising edge buffer list is the target ranging time value for the first target object, and the second rising edge trigger time in the same list is the target ranging time value for the second target object.

[0098] S203: Calculate the distance to the target object based on the target timing value.

[0099] In practical applications, the distance between the lidar and the target object can be obtained by multiplying half of the target timing value by the speed of light.

[0100] In practical applications, the distance between the lidar and each target object can be obtained by multiplying half of the target timing value corresponding to each target object by the speed of light.

[0101] It should be noted that, based on experimental simulations, in low signal-to-noise ratio scenarios, the detection distance of the ranging method provided in this application embodiment is increased by approximately 9.67m compared to the detection distance of traditional ranging methods.

[0102] As can be seen from the above, the ranging method provided in this application can improve the detection range of lidar in low signal-to-noise ratio scenarios and enhance the ranging performance of lidar in long-distance detection scenarios by extracting signal features that can represent the correlation between signal strengths within each signal segment and using signal features to determine the target ranging time value used to calculate the distance to the target object.

[0103] Since the aforementioned short-time average autocorrelation function requires sliding window calculation, it increases the consumption of system resources during the calculation process and prolongs the calculation time, reducing the efficiency of ranging. Therefore, another embodiment of this application provides another method for determining the signal characteristics of the original echo signal. Please refer to... Figure 6 , Figure 6 A schematic diagram illustrating the implementation flow of step S201 in a ranging method provided in another embodiment of this application is shown. Figure 6 As shown, in this embodiment of the application, S201 may include the following steps:

[0104] S601: Locate the zero-crossing signal segment of the original echo signal;

[0105] S602: Based on the continuous zero-crossing segment length threshold, the zero-crossing segments of the original echo signal are filtered;

[0106] S603: Calculate the signal characteristics of the zero-crossing signal segments obtained by the screening.

[0107] In practical applications, the starting position index t0 of the original echo signal can be determined based on a first preset threshold, and the next time t0 from the starting position index t0 can be used to determine the starting position index t0. 0+1 Traversing the original echo signal, if t 0+1 If the signal strength of the original echo signal at time t is greater than 0, then t 0+1 The time point is determined as the first zero-crossing index position. Then, the original echo signal is iterated until a time point with a signal strength less than 0 is found. It is then determined whether the time difference between the previous time point of the current signal strength less than 0 and the aforementioned first zero-crossing index position exceeds a second preset pulse width (i.e., a continuous zero-crossing segment length threshold). If the time difference exceeds the second preset pulse width, the signal segment between the first zero-crossing index position and the previous time point of the current signal strength less than 0 is determined as a zero-crossing signal segment. This process is repeated for the original echo signal until all zero-crossing signal segments contained within the original echo signal are found.

[0108] After identifying all zero-crossing signal segments contained in the original echo signal, the short-time average autocorrelation function of each zero-crossing signal segment is calculated to obtain the signal characteristic value of each zero-crossing signal segment.

[0109] Accordingly, S202 above may include the following steps:

[0110] The rising edge trigger time is determined based on the signal characteristics of the zero-crossing signal segment;

[0111] The rising edge trigger time is determined as the target ranging timing value.

[0112] In this embodiment of the application, determining the rising edge trigger time based on the signal characteristics of the zero-crossing signal segment may include the following steps:

[0113] Determine whether the signal characteristics of the zero-crossing signal segment are greater than a first preset threshold;

[0114] If the signal characteristics of the zero-crossing signal segment are greater than the first preset threshold, then the first zero-crossing index position of the zero-crossing segment is determined as the rising edge trigger time.

[0115] In practical applications, a first zero-crossing index buffer list and a rising edge buffer list can be created first. After determining the zero-crossing signal segment, it is calculated whether the signal characteristics of the zero-crossing signal segment exceed a first preset threshold. If the signal characteristics of the zero-crossing signal segment exceed the first preset threshold, the first zero-crossing index position in the first zero-crossing index buffer list is stored as the rising edge trigger time in the rising edge buffer list, and the first zero-crossing index buffer list is cleared. If the signal characteristics of the zero-crossing signal segment do not exceed the first preset threshold, the first zero-crossing index buffer list is cleared directly. The above steps are repeated until the original echo signal is traversed.

[0116] In practical applications, the target ranging timing value is determined by the rising edge trigger times stored in the rising edge cache list. If multiple rising edge trigger times exist in the rising edge cache list, each rising edge trigger time is determined as the target ranging timing value for its corresponding target object.

[0117] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0118] Based on the ranging method provided in the above embodiments, the present invention further provides embodiments of a ranging device that implements the above method embodiments.

[0119] Please see Figure 7 , Figure 7 This is a schematic diagram of a ranging device provided in an embodiment of this application. In this embodiment, the ranging device includes units used for performing... Figures 2 to 6 The steps in the corresponding embodiments. Please refer to the details. Figures 2 to 6 as well as Figures 2 to 6 The relevant descriptions in the corresponding embodiments are shown below. For ease of explanation, only the parts relevant to this embodiment are shown. Figure 7 As shown, the ranging device 7 includes: a feature extraction module 71, a timing value determination module 72, and a distance calculation module 73. Wherein:

[0120] The feature extraction module 71 is used to extract the signal features of the original echo signal; the signal features are the autocorrelation degree of the signal intensity of each signal segment in the original echo signal.

[0121] The timing value determination module 72 is used to determine the target ranging timing value based on the above signal characteristics.

[0122] The distance calculation module 73 is used to calculate the distance to the target object based on the target ranging time value mentioned above.

[0123] In one embodiment of this application, the feature extraction module 71 may include a selection unit, a calculation unit, and a traversal unit.

[0124] The selection unit is used to select signal segments based on a sliding window method;

[0125] The calculation unit is used to calculate the signal feature values ​​of the selected signal segments based on the short-time average autocorrelation function;

[0126] The traversal unit is used to slide a window through the original echo signal and output the signal characteristic curve of the original echo signal.

[0127] In one embodiment of this application, the timing value determination module 72 includes a first determination unit and a second determination unit.

[0128] The first determining unit is used to traverse the above signal characteristic curves and determine the rising edge trigger time of the above signal characteristic curves.

[0129] The second determining unit is used to determine the rising edge trigger time as the target ranging timing value.

[0130] In one embodiment of this application, the first determining unit is specifically used to determine the starting position index of the signal feature curve according to a first preset threshold. The starting position index is used for threshold detection, and the starting position index is the first position index of the signal feature curve that is not greater than the first preset threshold.

[0131] Create a rising edge cache list and a falling edge cache column. The rising edge cache list is used to store the rising edge trigger time, and the falling edge cache list is used to store the falling edge trigger time.

[0132] Starting from the starting position index, traverse the signal characteristic curve. If the signal characteristic is greater than the first preset threshold and the rising edge buffer list length is equal to the falling edge buffer list length, then perform linear interpolation based on the current position index and its previous position index to calculate the rising edge trigger time, and store the rising edge trigger time in the rising edge buffer list.

[0133] If the signal characteristic is less than the first preset threshold, and the length of the rising edge buffer list is 1 greater than the length of the falling edge buffer list, then linear interpolation is performed based on the current position index and the next position index to calculate the falling edge trigger time.

[0134] If the time difference between the falling edge trigger time and the last rising edge trigger time in the rising edge cache list is greater than or equal to the first preset pulse width, then the falling edge trigger time is stored in the falling edge cache list; otherwise, the last rising edge trigger time in the rising edge cache list is deleted.

[0135] In one embodiment of this application, the feature extraction module 71 includes a search unit, a filtering unit, and a calculation unit.

[0136] The search unit is used to find the zero-crossing segment of the original echo signal.

[0137] The filtering unit is used to filter the zero-crossing segments of the original echo signal based on a continuous zero-crossing segment length threshold.

[0138] The calculation unit is used to calculate the signal characteristics of the zero-crossing signal segments obtained by the above screening.

[0139] In one embodiment of this application, the timing value determination module 72 further includes a third determination unit.

[0140] The third determining unit is used to determine the rising edge trigger time based on the signal characteristics of the aforementioned zero-crossing signal segment.

[0141] In one embodiment of this application, the third determining unit is specifically used to determine whether the signal characteristics of the zero-crossing signal segment are greater than the first preset threshold; if the signal characteristics of the zero-crossing signal segment are greater than the first preset threshold, the first zero-crossing index position of the zero-crossing segment is determined as the rising edge trigger time.

[0142] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. Their specific functions and technical effects can be referred to the method embodiments section, and will not be repeated here.

[0143] Figure 8 This is a schematic diagram of the structure of a terminal device provided in another embodiment of this application. For example... Figure 8 As shown, the terminal device 8 provided in this embodiment includes: a processor 80, a memory 81, and a computer program 82 stored in the memory 81 and executable on the processor 80, such as a ranging program. When the processor 80 executes the computer program 82, it implements the steps in the various ranging method embodiments described above, for example... Figure 2 S201 to S203 are shown. Alternatively, when the processor 80 executes the computer program 82, it implements the functions of each module / unit in the above-described terminal device embodiments.

[0144] For example, the computer program 82 can be divided into one or more modules / units, which are stored in the memory 81 and executed by the processor 80 to complete this application. The one or more modules / units can be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 82 in the terminal device 8. For example, the computer program 82 can be divided into multiple units; please refer to the specific functions of each unit. Figure 7 The relevant descriptions in the corresponding embodiments are not repeated here.

[0145] The terminal device may include, but is not limited to, a processor 80 and a memory 81. Those skilled in the art will understand that... Figure 8 This is merely an example of terminal device 8 and does not constitute a limitation on terminal device 8. It may include more or fewer components than shown, or combine certain components, or different components. For example, the terminal device may also include input / output devices, network access devices, buses, etc.

[0146] The processor 80 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0147] The memory 81 can be an internal storage unit of the terminal device 8, such as a hard disk or memory of the terminal device 8. The memory 81 can also be an external storage device of the terminal device 8, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the terminal device 8. Furthermore, the memory 81 can include both internal and external storage units of the terminal device 8. The memory 81 is used to store the computer program and other programs and data required by the terminal device. The memory 81 can also be used to temporarily store data that has been output or will be output.

[0148] This application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, can implement the above-described ranging method.

[0149] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the above-described ranging method.

[0150] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the terminal device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0151] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.

[0152] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0153] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method of distance measurement, characterized by, The method comprises the following steps: extracting signal features of the original echo signal; the signal features are autocorrelation degrees of signal strengths of each signal segment in the original echo signal; determining a target ranging timing value according to the signal features; calculating the distance of a target object according to the target ranging timing value; the step of extracting the signal features of the original echo signal comprises the following steps: finding all zero-crossing signal segments of the original echo signal; screening the zero-crossing signal segments of the original echo signal based on a continuous zero-crossing signal segment length threshold; calculating the signal features of the screened zero-crossing signal segments; wherein the zero-crossing signal segment is a signal segment between the first zero-crossing index position and the last time point before the time point at which the current signal is less than 0, in the case that the time difference between the first zero-crossing index position and the last time point before the time point at which the current signal is less than 0 is greater than the continuous zero-crossing segment length threshold.

2. The ranging method according to claim 1, wherein, The step of extracting the signal features of the original echo signal comprises the following steps: selecting signal segments in a sliding window manner; calculating signal feature values of the selected signal segments based on a short-time average autocorrelation function; traversing the original echo signal in a sliding window manner, and outputting a signal feature curve of the original echo signal.

3. The ranging method according to claim 2, wherein, The step of determining a target ranging timing value according to the signal features comprises the following steps: traversing the signal feature curve to determine a rising edge trigger time of the signal feature curve; determining the rising edge trigger time as the target ranging timing value.

4. The ranging method according to claim 3, wherein, The step of traversing the signal feature curve to determine a rising edge trigger time of the signal feature curve comprises the following steps: determining a starting position index of the signal feature curve according to a first preset threshold, the starting position index being used for threshold detection, the starting position index being a position index of the signal feature curve at which the first preset threshold is not greater than the first preset threshold; creating a rising edge cache list and a falling edge cache list, the rising edge cache list being used for storing rising edge trigger times, and the falling edge cache list being used for storing falling edge trigger times; starting to traverse the signal feature curve from the starting position index, if the signal feature is greater than the first preset threshold and the length of the rising edge cache list is equal to the length of the falling edge cache list, performing linear interpolation based on the current position index and the previous position index of the current position index to calculate a rising edge trigger time, and storing the rising edge trigger time in the rising edge cache list; if the signal feature is less than the first preset threshold and the length of the rising edge cache list is greater than the length of the falling edge cache list by 1, performing linear interpolation based on the current position index and the next position index of the current position index to calculate a falling edge trigger time; if the time difference between the falling edge trigger time and the last rising edge trigger time in the rising edge cache list is greater than or equal to a first preset pulse width, storing the falling edge trigger time in the falling edge cache list, otherwise deleting the last rising edge trigger time in the rising edge cache list.

5. The method of Claim 1, wherein, The step of determining a target ranging timing value according to the signal features comprises the following steps: determining a rising edge trigger time according to the signal features of the zero-crossing signal segments; The rising edge trigger moment is determined as a target ranging timing value.

6. The method of claim 5, wherein, The rising edge trigger moment is determined according to a signal feature of the zero-crossing signal segment, and the method comprises the steps of: determining whether the signal feature of the zero-crossing signal segment is greater than a first preset threshold value; if the signal feature of the zero-crossing signal segment is greater than the first preset threshold value, performing linear interpolation based on a first zero-crossing index position of the zero-crossing segment and a previous index position of the first zero-crossing index position to obtain the rising edge trigger moment.

7. A ranging device, characterized by comprise: a feature extraction module configured to extract a signal feature of an original echo signal; the signal feature is an autocorrelation degree of signal intensity of each signal segment; a timing value determination module configured to determine a target ranging timing value according to the signal feature; a distance calculation module configured to calculate a distance of a target object according to the target ranging timing value; the signal feature of the original echo signal comprises: finding all zero-crossing signal segments of the original echo signal; filtering the zero-crossing signal segments of the original echo signal based on a continuous zero-crossing signal segment length threshold value; calculating a signal feature of the filtered zero-crossing signal segment; wherein the zero-crossing signal segment is a signal segment between the first zero-crossing index position and the previous time of the time when the current signal is less than 0, in the case that the time difference between the previous time of the time when the current signal is less than 0 and the first zero-crossing index position exceeds the continuous zero-crossing segment length threshold value.

8. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes computer readable instructions to implement the ranging method of any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 8. The computer readable instructions are executed by the processor to implement the ranging method of any one of claims 1 to 6.

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