Target ranging method, device and detection equipment

Abstract

The application provides a target ranging method and device and a detection equipment, and relates to the technical field of radar measurement. The target ranging method comprises the following steps: periodically modulating a transmission pulse by using a preset modulation signal to obtain a transmission pulse in a single pulse period; transmitting transmission pulses in multiple pulse intervals in the single pulse period in sequence, and receiving multiple echo pulses in sequence; determining a measurement distance corresponding to each of the multiple echo pulses according to the transmission time of the nearest transmission pulse and the multiple echo pulses; obtaining a sequence of adjacent measurement distance difference values; finding a sequence closest to the sequence of adjacent measurement distance difference values from a plurality of multi-period regular sequences corresponding to the preset modulation signal; determining a target multi-period; and obtaining an actual distance of a target object to be measured according to the target multi-period and the measurement distance corresponding to the echo pulse. The method provided by the application can obtain the actual distance of the target object to be measured only by determining the target multi-period, and the calculation process is simple and efficient.

Description

Technical Field

[0001] This invention relates to the field of radar measurement technology, and more specifically, to a target ranging method, apparatus, and detection equipment. Background Technology

[0002] Calculating the target distance using TOF (time-of-flight) lidar hinges on determining the time interval between the transmitted pulse and its corresponding echo pulse. However, if the next transmitted pulse is emitted before the echo pulse of the previous transmitted pulse returns, a multi-cycle phenomenon occurs. This prevents a one-to-one correspondence between the transmitted and echo pulses, leading to distance ambiguity and making it impossible to determine the target distance.

[0003] Currently, existing technologies mainly determine multiple periods by using echo intensity or target reflectivity, or by using other known data to predetermine multiple periods. However, determining multiple periods by using echo intensity or target reflectivity is easily affected by factors such as distance, target reflectivity, the angle between the target and the incident laser, and the effective reflection cross section of the target, resulting in low accuracy in determining multiple periods. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a target distance measurement method, apparatus, and detection device, so that by simply comparing the sequence of adjacent echo measurement distance differences with a predetermined regular sequence, the corresponding multiple periods of the adjacent echo measurement distance difference sequence can be determined, thereby obtaining the target distance of the target object to be measured.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

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

[0007] The transmit pulse is periodically modulated using a preset modulation signal to obtain a transmit pulse with a single pulse period, wherein the single pulse period includes transmit pulses with multiple pulse intervals corresponding to the preset modulation signal;

[0008] The system sequentially transmits multiple pulses at intervals within a single pulse period and sequentially receives multiple echo pulses reflected back from the target object.

[0009] The measurement distance corresponding to the plurality of echo pulses is determined based on the reception time of the plurality of echo pulses and the transmission time of the nearest transmission pulse of the plurality of echo pulses;

[0010] Based on the measurement distances corresponding to the multiple echo pulses, a sequence of adjacent measurement distance differences for a single pulse period is obtained;

[0011] Based on the adjacent measurement distance difference sequence, the sequence closest to the adjacent measurement distance difference sequence is found from the multiple multi-period regular sequences corresponding to the preset modulation signal, and the target multi-period is determined. The multi-period is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse. Each multi-period regular sequence records the adjacent measurement distance difference sequence pre-calculated under each multi-period.

[0012] The actual distance of the target object is obtained based on the target multi-cycle and the measurement distance corresponding to the echo pulse.

[0013] In an optional implementation, the step of finding the sequence closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal, and determining the target multi-period, includes:

[0014] Based on the adjacent measurement distance difference sequence, determine the target regularity sequence that is closest to the adjacent measurement distance difference sequence from the plurality of multi-period regularity sequences;

[0015] The multi-periods corresponding to the target pattern sequence are determined as the target multi-periods.

[0016] In an optional implementation, determining the target regularity sequence that is closest to the adjacent measurement distance difference sequence from the plurality of multi-period regularity sequences based on the adjacent measurement distance difference sequence includes:

[0017] Based on the number of positive, negative, and zero values ​​in the adjacent measurement distance difference sequence, the target regularity sequence is determined from the multiple multi-period regularity sequences that match the number of values.

[0018] In an optional implementation, determining the target regularity sequence that is closest to the adjacent measurement distance difference sequence from the plurality of multi-period regularity sequences based on the adjacent measurement distance difference sequence includes:

[0019] Based on the average positive and / or average negative values ​​in the adjacent measurement distance difference sequence, the target regular sequence is determined from the multiple multi-period regular sequences to be the regular sequence corresponding to the range of the average values.

[0020] In an optional implementation, based on the adjacent measurement distance difference sequence, determining the target regularity sequence that is closest to the adjacent measurement distance difference sequence from the plurality of multi-period regularity sequences includes:

[0021] Calculate the correlation coefficients of the adjacent measurement distance difference sequence and the multiple multi-period regular sequences respectively;

[0022] Based on the correlation coefficient, the target regular sequence is determined from the plurality of multi-period regular sequences.

[0023] In an optional implementation, calculating the correlation coefficients of the adjacent measurement distance difference sequence and the plurality of multi-period regular sequences respectively includes:

[0024] Calculate the cross-correlation coefficients of the adjacent measurement distance difference sequence and the multiple multi-period regular sequences respectively;

[0025] Based on the cross-correlation coefficient, the target regular sequence is determined from the plurality of multi-period regular sequences.

[0026] In an optional implementation, calculating the correlation coefficients of the adjacent measurement distance difference sequence and the plurality of multi-period regular sequences respectively includes:

[0027] Calculate the class correlation coefficient between the adjacent measurement distance difference sequence and the multiple multi-period regular sequences;

[0028] Based on the class correlation coefficient, the target regular sequence is determined from the plurality of multi-period regular sequences.

[0029] In an optional implementation, before performing transmission modulation with a preset modulation signal to obtain a transmit pulse of a single pulse period, the method further includes:

[0030] The preset modulation signal is generated using a preset waveform based on the preset center frequency pulse interval, preset time interval, and preset number of pulse intervals.

[0031] Secondly, embodiments of this application also provide a target ranging device, comprising:

[0032] A modulation module is used to periodically modulate a transmit pulse using a preset modulation signal to obtain a transmit pulse with a single pulse period, wherein the single pulse period includes transmit pulses with multiple pulse intervals corresponding to the preset modulation signal;

[0033] The transceiver module is used to sequentially transmit the multiple pulse intervals within the single pulse period, and sequentially receive the multiple echo pulses reflected back by the target object under test.

[0034] The calculation module is used to determine the measurement distance corresponding to the plurality of echo pulses based on the reception time of the plurality of echo pulses and the transmission time of the nearest transmission pulse of the plurality of echo pulses;

[0035] The calculation module is also used to obtain a sequence of adjacent measurement distance differences for a single pulse period based on the measurement distances corresponding to the plurality of echo pulses.

[0036] The calculation module is further configured to find the sequence closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence, and determine the target multi-period, wherein the multi-period is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse, and each multi-period regular sequence records: the adjacent measurement distance difference sequence pre-calculated under each multi-period;

[0037] The calculation module is also used to obtain the actual distance of the target object to be measured based on the target multi-cycle and the measurement distance corresponding to the echo pulse.

[0038] Thirdly, this application embodiment also provides a detection device, the detection device including: a modulation module, a transceiver module, and a computing module; wherein, the modulation module is connected to the transceiver module, and the transceiver module is connected to the computing module;

[0039] The modulation module is used to periodically modulate the transmitted pulse with a preset modulation signal to obtain a transmitted pulse with a single pulse period, wherein the single pulse period includes: a transmitted pulse with multiple pulse intervals corresponding to the preset modulation signal;

[0040] The transceiver module is used to sequentially transmit the multiple pulse intervals within the single pulse period, and sequentially receive the multiple echo pulses reflected back by the target object under test.

[0041] The calculation module is used to determine the measurement distance corresponding to the plurality of echo pulses based on the reception time of the plurality of echo pulses and the transmission time of the nearest transmission pulse of the plurality of echo pulses;

[0042] The calculation module is also used to obtain a sequence of adjacent measurement distance differences for a single pulse period based on the measurement distances corresponding to the plurality of echo pulses.

[0043] The calculation module is further configured to find the sequence closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence, and determine the target multi-period, wherein the multi-period is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse, and each multi-period regular sequence records: the adjacent measurement distance difference sequence pre-calculated under each multi-period;

[0044] The calculation module is also used to obtain the actual distance of the target object to be measured based on the target multi-cycle and the measurement distance corresponding to the echo pulse.

[0045] The beneficial effects of this application are:

[0046] This application provides a target ranging method, apparatus, and detection device. The target ranging method includes: periodically modulating a transmitted pulse with a preset modulation signal to obtain a transmitted pulse with a single pulse period; then sequentially transmitting multiple transmitted pulses with multiple pulse intervals within the single pulse period; and sequentially receiving multiple echo pulses reflected back by the target object; determining the measurement distance corresponding to the multiple echo pulses based on the reception time of the multiple echo pulses and the transmission time of the nearest transmitted pulse among the multiple echo pulses; then obtaining a sequence of adjacent measurement distance differences for a single pulse period based on the measurement distances corresponding to the multiple echo pulses; finding the sequence closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence to determine the target multi-period; and finally obtaining the actual distance of the target object based on the target multi-period and the measurement distances corresponding to the echo pulses. The method of this application only requires acquiring multiple echo pulses of the target object and the time of the transmitted pulses. Based on the multiple echo pulses, it calculates the adjacent measurement distance difference sequence of a single pulse period, and determines the target multi-period corresponding to the adjacent measurement distance difference sequence from the multiple multi-period regular sequences corresponding to the preset modulation signal. The target distance of the target object can then be obtained without the need for other data support and with low hardware requirements for the detection equipment. At the same time, calculating multiple adjacent measurement distance differences can reduce the interference of noise on the determination of the target multi-period and improve the accuracy of the determination of the target multi-period. In addition, the determination of the target multi-period only requires comparing the adjacent echo measurement distance difference sequence with the pre-determined regular sequence. The calculation process is relatively simple and the solution efficiency is high. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 A multi-cycle schematic diagram provided for an embodiment of this application;

[0049] Figure 2(a) is one of the schematic diagrams of a multi-cycle echo provided in an embodiment of this application;

[0050] Figure 2(b) is a second schematic diagram of a multi-cycle echo provided in an embodiment of this application;

[0051] Figure 2(c) is a third schematic diagram of a multi-cycle echo provided in an embodiment of this application;

[0052] Figure 3(a) is one of the schematic diagrams of the difference law of adjacent measurement distances in multiple cycles provided by the embodiments of this application;

[0053] Figure 3(b) is a second schematic diagram of the difference law of adjacent measurement distances in multiple cycles provided by an embodiment of this application;

[0054] Figure 3(c) is a third schematic diagram of the law of difference between adjacent measurement distances in multiple cycles provided in the embodiments of this application;

[0055] Figure 4 A schematic flowchart illustrating a target ranging method provided in an embodiment of this application;

[0056] Figure 5 A schematic flowchart illustrating another target ranging method provided in this application embodiment;

[0057] Figure 6 A multi-cycle schematic diagram illustrating the derivation of adjacent measurement distance differences is provided in this application embodiment;

[0058] Figure 7 A flowchart illustrating another target ranging method provided in this application embodiment;

[0059] Figure 8 This is a schematic diagram of the functional modules of a target ranging device provided in an embodiment of this application. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0061] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0062] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this application is usually placed in, it is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0063] Furthermore, the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Additionally, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0064] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0065] When using a detection device to measure the distance to a target object, the target distance is determined by the timing of the pulse emitted by the detection device, the timing of the received echo pulse reflected from the target object, and the velocity of the pulse medium. However, due to varying distances between the target object and the detection device, a multi-cycle phenomenon may occur where the next pulse is emitted before the detection device receives the reflected echo pulse. This makes it impossible to correlate the reflected echo pulse with the emitted pulse, thus making it impossible to determine the target distance. However, through repeated experimental verification, it has been found that when the detection device uses a preset modulation signal for wave modulation, the fixed pattern of the emitted pulse modulation signal allows for the determination of a fixed pattern of the difference between adjacent measured distances of the target object under different multi-cycle conditions. By comparing this pattern with the fixed pattern of the difference between adjacent measured distances of the target object under different multi-cycle conditions, a target multi-cycle difference pattern that conforms to the pattern of the difference between adjacent measured distances of the target object can be determined. Here, the measured distance of the target object refers to the distance corresponding to the time difference between the echo pulse and the nearest emitted pulse.

[0066] Based on this, the present application provides a target distance measurement method. By determining the measurement distances corresponding to multiple echo pulses of the target object to be measured, determining the sequence of adjacent measurement distance differences of the target object in a single pulse cycle, and determining the target multi-cycle corresponding to the adjacent measurement distance difference sequence according to the regular sequence of multiple multi-cycles corresponding to the preset modulation signal, the target distance of the target object to be measured can be accurately obtained according to the target multi-cycle and the measurement distances corresponding to multiple echo pulses.

[0067] This application provides a detailed example illustrating the fixed pattern of the difference in the measurement distance between adjacent targets under different multi-cycle conditions using a preset modulation signal. Figure 1 Figure 2(a) is one of the multi-cycle echo diagrams provided in this application embodiment; Figure 2(b) is another multi-cycle echo diagram provided in this application embodiment; Figure 2(c) is a third multi-cycle echo diagram provided in this application embodiment; Figure 3(a) is one of the multi-cycle adjacent measurement distance difference diagrams provided in this application embodiment; Figure 3(b) is another multi-cycle adjacent measurement distance difference diagram provided in this application embodiment; Figure 3(c) is a third multi-cycle adjacent measurement distance difference diagram provided in this application embodiment.

[0068] like Figure 1 As shown, when the target object is close, such as Figure 1 Target objects O1 and O2 on medium and tall buildings return before the next transmission pulse of the preset modulation signal, as shown in Figure 2(a). At this time, the target echo pulses R1 and R2 corresponding to target object O1 and target echo pulses R2 corresponding to target object O2 are within the first multi-cycle range M0 of the preset modulation signal. Since the target distance between adjacent echoes is not significantly different, it can be assumed that the difference in distance between adjacent targets is 0. Here, the target measurement distance refers to the distance corresponding to the time difference between the target echo and the nearest transmitted pulse. Therefore, within the first multi-cycle range M0, the difference in measurement distance between adjacent echoes is approximately 0.

[0069] When the target object is far away, such as Figure 1For targets O3 and O4 on tall buildings, the target echo pulses R3 and R4 corresponding to target O3 return after the next transmission pulse of the preset modulation signal is transmitted, as shown in Figure 2(b). At this time, the target echo pulses R3 and R4 corresponding to target O3 and target O4 are within the second multi-cycle range M1 of the preset modulation signal. Within the second multi-cycle range M1, and the target echo pulses R3 and R4 are separated from the transmission pulses E3 and E4 by one pulse interval, the difference in the measurement distance between adjacent echoes is related to the size of the single pulse interval.

[0070] When the distance to the target object is at its farthest, such as Figure 1 For targets O5 and O6 on tall buildings, the target echo pulses R5 and R6 corresponding to target O5 return after being transmitted by the next transmission pulse under the preset modulation signal, as shown in Figure 2(c). At this time, the target echo pulses R5 and R6 corresponding to target O5 and target O6 are within the third multi-cycle range M2 of the preset modulation signal. Since the target echo pulses R5 and R6 differ from the transmission pulses E5 and E6 by two pulse intervals, the difference in the measurement distance between adjacent echoes is related to the size of the interval between the two adjacent pulses.

[0071] Therefore, the difference in the measurement distance between adjacent echoes of the target object is related to the number of pulse intervals in the preset modulation signal transmission pulse. Thus, the transmission pulse is modulated according to the typical Pulse Repetition Interval (PRI) modulation method of the detection equipment. After PRI modulation, the transmission pulse consists of consecutive pulse intervals. Within one pulse interval, there are multiple pulse intervals. After a complete pulse interval, the next pulse interval begins. The duration of each pulse interval is {t1, t2, ..., t...}. n}, and {t1, t2, ..., t n The pulse interval t, whose values ​​are all close to the center frequency of the transmitted pulse, is... c The interval between each pulse is greater than 0.85t. c And less than 1.15t c Since the modulation pattern of the transmitted pulse is fixed, i.e., the pulse interval is fixed, a fixed pattern can be obtained for the difference in adjacent measurement distances under different multi-cycle conditions.

[0072] As shown in Figure 3(a), for a target object located in the first multi-period range M0, the emitted pulse E i Corresponding echo pulse R j The measured distance is l k , lk That is, the actual measured distance of the target, and similarly l k+1 Also for E i+1 The actual measured distance to the target. k+1 With l k The difference in distance between adjacent echo measurements d0 0 The value is close to 0.

[0073] As shown in Figure 3(b), for a target object located in the second multi-period range M1, the emitted pulse E i Corresponding echo R j The measured distance is l k , l k Subtract the emitted pulse E from the actual distance i and the emitted pulse E i+1 The pulse interval between them corresponds to the distance. Therefore, l k With the emitted pulse E i and the emitted pulse E i+1 The pulse intervals between them are strongly correlated; similarly, the transmitted pulse E i+1 The corresponding measurement distance l k+1 With the emitted pulse E i+1 and the emitted pulse E i+2 The pulse intervals between them are strongly correlated. k+1 With l k Interval difference d0 1 With the emitted pulse E i and the emitted pulse E i+1 Interval and emission pulse E i+1 and the emitted pulse E i+2 The difference between two adjacent pulse intervals is strongly correlated. d0 1 The specific value is related to the pulse modulation method, that is, the position of the modulation signal and its echo pulse within the pulse interval period.

[0074] As shown in Figure 3(c), for a target located in the third multi-period range M2, the emitted pulse E i Measurement distance l corresponding to the echo pulse k With the emitted pulse E i Emit pulse E i+1 Inter-pulse interval plus transmitted pulse E i+1 Emit pulse E i+2 The pulse interval is related. Transmit pulse E i+1 Measurement distance l corresponding to the echo pulse k+1 With the emitted pulse E i+1 Emit pulse E i+2 Inter-pulse interval plus transmitted pulse E i+2 Emit pulse E i+3 The pulse interval is related. Therefore, l k+1 With lk The difference d0 between 2 With the emitted pulse E i+2 Emit pulse E i+3 Inter-pulse interval minus the transmitted pulse E i Emit pulse E i+1 The pulse interval is related.

[0075] Based on the relationship between the adjacent measurement distance of the echo pulse and the corresponding pulse interval of the preset modulation signal, this application obtains a fixed pattern of the difference between adjacent measurement distances of the target object under different multi-cycles of the preset modulation signal. Thus, the target multi-cycle of the target object to be measured can be determined based on the fixed pattern, and the target distance of the target object to be measured can be determined in the end.

[0076] The target distance measurement method provided in this application will be explained in detail below with reference to the accompanying drawings and specific examples. Figure 4 This is a schematic flowchart illustrating a target ranging method provided in an embodiment of this application. Figure 4 As shown, the method includes:

[0077] S101. The transmitted pulse is periodically modulated using a preset modulation signal to obtain a transmitted pulse with a single pulse period.

[0078] In this embodiment, the preset modulation signal may include: sawtooth wave signal, sine wave signal, triangular wave signal, and stepped wave signal, etc. The transmitted pulse is periodically modulated by the preset modulation signal. Since the transmitted pulse has a series of continuous pulse interval periods, and there are multiple pulse intervals within each pulse interval period, after transmitting a complete pulse interval period, the next pulse interval period is started, thereby obtaining a single pulse period of transmitted pulse in multiple pulse periods. The single pulse period includes: transmitted pulses of multiple pulse intervals corresponding to the preset modulation signal.

[0079] It should be noted that, in addition to laser pulses, the signals emitted by the detection equipment can also be radio pulses, radar pulses, and sound pulses, etc., and the transmission speeds of signals with different transmission media are different.

[0080] S102. Transmit multiple pulses with multiple pulse intervals within a single pulse period in sequence, and receive multiple echo pulses reflected back by the target object in sequence.

[0081] S103. Determine the measurement distance corresponding to the multiple echo pulses based on the reception time of the multiple echo pulses and the transmission time of the most recent transmission pulse of the multiple echo pulses.

[0082] Specifically, the measurement distance corresponding to each echo pulse is determined based on the time of receiving each echo pulse, the transmission time of the nearest transmitted pulse for each echo pulse, and the propagation speed of the preset modulation signal.

[0083] S104. Based on the measurement distances corresponding to multiple echo pulses, obtain the sequence of adjacent measurement distance differences for a single pulse period.

[0084] Specifically, the difference between the measurement distances corresponding to adjacent echo pulses is calculated to obtain the measurement distance difference between multiple adjacent echo pulses. Then, according to the receiving time order of multiple echo pulses, the differences between multiple adjacent echo pulses corresponding to multiple echo pulses are sorted to obtain the sequence of adjacent measurement distance differences for a single pulse period.

[0085] S105. Based on the adjacent measurement distance difference sequence, find the sequence that is closest to the adjacent measurement distance difference sequence from the multiple multi-period regular sequences corresponding to the preset modulation signal, and determine the target multi-period.

[0086] Among them, the multi-cycle is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse. The regular sequence of each multi-cycle records the sequence of adjacent measurement distance differences calculated in advance under each multi-cycle.

[0087] From multiple multi-period regular sequences corresponding to the preset modulation signal, determine the multi-period regular sequence that is most similar to the adjacent measurement distance difference sequence as the target multi-period.

[0088] S106. Based on the target's multi-cycle and the measurement distance corresponding to the echo pulse, the actual distance of the target object to be measured is obtained.

[0089] The target's multi-cycle period is determined, as well as the number of multi-cycle periods between multiple echo pulses and their corresponding transmitted pulses. If the target's multi-cycle period is the second multi-cycle period, then the difference between multiple echo pulses and their corresponding transmitted pulses is determined to be two pulse intervals. Knowing the reception time of each echo pulse and the time between the two pulse intervals, the transmission time of the corresponding transmitted pulse for each echo pulse can be determined. Therefore, the reception time of each echo pulse minus the transmission time of the corresponding transmitted pulse, multiplied by the transmission speed corresponding to the transmitted pulse, yields the round-trip distance of the target object. Finally, dividing by 2 gives the target distance of the target object.

[0090] In summary, the embodiments of this application provide a target ranging method, comprising: periodically modulating a transmitted pulse with a preset modulation signal to obtain a transmitted pulse with a single pulse period; then sequentially transmitting multiple transmitted pulses with multiple pulse intervals within the single pulse period; and sequentially receiving multiple echo pulses reflected back by the target object; determining the measurement distance corresponding to the multiple echo pulses based on the reception time of the multiple echo pulses and the transmission time of the nearest transmitted pulse among the multiple echo pulses; then obtaining a sequence of adjacent measurement distance differences for a single pulse period based on the measurement distances corresponding to the multiple echo pulses; finding the sequence closest to the sequence of adjacent measurement distance differences from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence to determine the target multi-period; and finally obtaining the actual distance of the target object based on the target multi-period and the measurement distances corresponding to the echo pulses. The method of this application only requires acquiring multiple echo pulses of the target object and the time of the transmitted pulses. Based on the multiple echo pulses, it calculates the adjacent measurement distance difference sequence of a single pulse period, and determines the target multi-period corresponding to the adjacent measurement distance difference sequence from the multiple multi-period regular sequences corresponding to the preset modulation signal. The target distance of the target object can then be obtained without the need for other data support and with low hardware requirements for the detection equipment. Calculating multiple adjacent measurement distance differences can reduce noise interference in the determination of the target multi-period and improve the accuracy of the target multi-period determination. In addition, the determination of the target multi-period only requires comparing the adjacent echo measurement distance difference sequence with the pre-determined regular sequence. The calculation process is relatively simple and the solution efficiency is high.

[0091] Based on the target ranging method provided in the above embodiments, this application also provides another possible implementation of the target ranging method. Figure 5 A schematic flowchart of another target ranging method provided in this application embodiment is shown below. Figure 5 As shown, based on the adjacent measurement distance difference sequence, the target multi-period is determined from multiple multi-period regular sequences corresponding to the preset modulation signal, including:

[0092] S201. Based on the adjacent measurement distance difference sequence, determine the target regular sequence that is closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences.

[0093] S202. Determine the target multi-period corresponding to the target pattern sequence as the target multi-period.

[0094] In this embodiment, the multiple multi-period regular sequences corresponding to the preset modulation signal are first compared with the adjacent measurement distance difference sequences to determine the target regular sequence that is closest to the adjacent measurement distance difference sequences. Then, the multiple periods corresponding to the target regular sequence are used to determine the multiple periods corresponding to the adjacent measurement distance difference sequences.

[0095] For example, a regular sequence of multiple multi-periods corresponding to a sawtooth wave modulated signal is provided, as shown in Table 1, and the pulse interval within a single pulse interval period is {t}. c -2t d , t c -t d , t c , t c +t d , t c +2t d}, where l d For t d For the corresponding distance, if the sawtooth wave modulation signal is a laser pulse signal, then l d =t d ·c / 2, where c is the speed of light.

[0096] Table 1. Difference in adjacent measurement distances under multiple cycles of sawtooth wave modulated signal.

[0097]

[0098] Where pos is the position within the pulse interval period, indicating the position of the pulse interval within the pulse interval period. The pulse interval size is t. c -2t d The position of the pulse corresponding to the pulse interval period is 0, t c The corresponding position within the pulse interval period is 2. Similarly, the positions corresponding to different pulse intervals within a single pulse period can be obtained. For a target echo pulse, its position within the pulse interval period is the position corresponding to its pulse interval. If the target echo pulse falls on a pulse interval of magnitude t... c -t d If the pulse interval is within a certain range, then the position of the echo pulse within the pulse interval period is 1.

[0099] Figure 6 This application provides a multi-cycle schematic diagram for deriving the difference between adjacent measurement distances, as shown in the embodiments of this application. Figure 6 As shown, if the sequence of adjacent measurement distance differences of the target object to be measured is {d} k d k+1 d k+2 d k+3 d k+4 d k+5} is {2l d , 2l d , 2l d -3l d -3l d If we calculate the distance difference between adjacent measurements of the target object, we can determine that the target multi-cycle corresponding to the distance difference is 3, that is, the echo pulse of the target object is separated from the corresponding transmitted pulse by three pulse intervals.

[0100] This application embodiment also provides another possible implementation of target distance measurement through a method for determining a target pattern sequence. Based on adjacent measured distance difference sequences, it determines the target pattern sequence closest to the adjacent measured distance difference sequence from multiple multi-period pattern sequences, including:

[0101] Based on the number of positive, negative, and zero values ​​in the adjacent measurement distance difference sequence, the target regularity sequence is determined from multiple multi-period regularity sequences that match the number of values.

[0102] Specifically, taking the multiple multi-period regular sequences corresponding to the sawtooth wave modulation signal in Table 1 as an example, if the number of positive values ​​in the adjacent measurement distance difference sequence within a single pulse period is 1, the number of negative values ​​is 4, and the number of zero values ​​is 0, then the regular sequence with matching numbers in the adjacent measurement distance difference sequence can be determined as the regular sequence corresponding to the multiple period of 1 in Table 1. Therefore, the target multiple period corresponding to the adjacent measurement distance difference sequence is determined to be 1.

[0103] Optionally, based on the average positive and / or average negative values ​​in the adjacent measurement distance difference sequence, the target regular sequence is determined from multiple multi-period regular sequences to be the regular sequence corresponding to the range of the average values.

[0104] Specifically, taking the sawtooth wave modulation signal corresponding to multiple multi-period regular sequences in Table 1 above as an example, if the average positive value of the difference between adjacent measured distances within a single pulse period is 2l... d The average value of negative values ​​is -3l d Then, the regular sequence of the range of the average value in the adjacent measurement distance difference sequence can be determined as the regular sequence corresponding to the multi-period of 3 in Table 1, and the target multi-period corresponding to the adjacent measurement distance difference sequence is determined to be 3.

[0105] This application also provides various methods for determining target pattern sequences, which, based on adjacent measurement distance difference sequences, determine the target pattern sequence that is closest to the adjacent measurement distance difference sequence from multiple multi-period pattern sequences, including:

[0106] This application also provides another possible method for target ranging through a different method for determining the target's regularity sequence. Figure 7 This is a flowchart illustrating another target ranging method provided in the embodiments of this application, as shown below. Figure 7 As shown, based on the adjacent measurement distance difference sequence, from multiple multi-period regularity sequences, the target regularity sequence that is closest to the adjacent measurement distance difference sequence is determined, including:

[0107] S301. Calculate the correlation coefficients of adjacent measurement distance difference sequences and multiple multi-period regular sequences respectively.

[0108] S302. Based on the correlation coefficient, determine the target regular sequence from multiple multi-period regular sequences.

[0109] The correlation coefficient characterizes the similarity between the adjacent measurement distance difference sequence and the multiple multi-period regular sequence. The higher the similarity, the closer the adjacent measurement distance difference sequence is to the target multi-period regular sequence.

[0110] Therefore, the correlation coefficient between the adjacent measurement distance difference sequence and the regularity sequence of each multi-period is calculated, and the regularity sequence of the multi-period with the largest correlation coefficient with the adjacent measurement distance difference sequence is selected as the target regularity sequence.

[0111] Optionally, the cross-correlation coefficients of adjacent measurement distance difference sequences and multiple multi-period regular sequences can be calculated separately.

[0112] Based on the cross-correlation coefficient, the target regular sequence is determined from multiple multi-period regular sequences.

[0113] Specifically, the cross-correlation algorithm is used to calculate the cross-correlation coefficient between the adjacent measurement distance difference sequence and the regularity sequence of each multi-period, and the regularity sequence of the multi-period with the largest cross-correlation coefficient with the adjacent measurement distance difference sequence is selected as the target regularity sequence.

[0114] Optionally, the class correlation coefficients of adjacent measurement distance difference sequences and multiple multi-period regular sequences can be calculated.

[0115] Based on the class correlation coefficient, the target regular sequence is determined from multiple multi-period regular sequences.

[0116] Specifically, the class correlation algorithm is used to calculate the class correlation coefficient between the adjacent measurement distance difference sequence and the regularity sequence of each multi-period, and the regularity sequence of the multi-period with the largest class correlation coefficient with the adjacent measurement distance difference sequence, i.e. the closest to 1, is selected as the target regularity sequence.

[0117] The class correlation coefficient is expressed as follows:

[0118] r(X,Y)=Cov(X,Y) / Var[X)

[0119] X represents the sequence of differences between adjacent measurements, Y represents multiple periodic regular sequences, Cov(X,Y) is the covariance of X and Y, expressed as Cov(X,Y)=E(XY)–E(X)E(Y), where E(X) is the expected value of X, and E(Y) is the expected value of Y. Var[X] is the variance of X, expressed as Var[X]=E(XY)E( ... 2 )–E2 (X). The sufficient but not necessary condition for r(X,Y)=b is that there exists a constant a such that Y=a+bX holds. Therefore, the sufficient but not necessary condition for r(X,Y)=1 is that there exists a constant a such that Y=a+X holds. Thus, the multi-periodic regularity sequence with r(X,Y)=1 is determined as the target regularity sequence.

[0120] It should be noted that the various methods for determining the target pattern sequence provided in the embodiments of this application can be used individually to determine the target pattern sequence, or they can be used in combination to make the final determined target pattern sequence more accurate. The specific number of determination methods used is not limited here.

[0121] In the method provided in this application embodiment, the correlation coefficients of adjacent measurement distance difference sequences and multiple multi-period regular sequences are calculated respectively, and the target regular sequence is determined from the multiple multi-period regular sequences based on the correlation coefficients. Thus, the target multi-period can be determined based on the target regular sequence, which facilitates accurate calculation of the target distance of the target object to be measured.

[0122] This application embodiment also provides another possible implementation of the target ranging method, which, before obtaining a single-pulse-cycle transmitted pulse by using a preset modulation signal for wave modulation, further includes:

[0123] Based on the preset center frequency pulse interval, preset time interval, and preset number of pulse intervals, a preset waveform is used to generate a preset modulation signal.

[0124] The preset waveform may include sawtooth wave, sine wave, triangular wave and stepped wave, etc., so as to generate the sawtooth wave signal, sine wave signal, triangular wave signal and stepped wave signal respectively according to the preset center frequency pulse interval, preset time interval and preset number of pulse intervals of the preset waveform.

[0125] For example, the multiple multi-cycle regular sequences corresponding to different preset modulation signals are different. Table 1 above describes the multiple multi-cycle regular sequences corresponding to the sawtooth wave modulation signal. Similarly, the multiple multi-cycle regular sequences corresponding to modulation signals such as sine wave signals, triangular wave signals, and stepped wave signals provided in this application embodiment are shown as follows:

[0126] Table 2. Difference in adjacent measurement distances under multiple cycles of sinusoidal modulated signal.

[0127]

[0128]

[0129] Wherein, the pulse interval within a single pulse interval period of the sinusoidal modulated signal is {t}. c, t c +t d , t c +t d , t c , t c -t d , t c -t d}, t c Preset center frequency pulse interval, t d The preset time interval and the preset number of pulse intervals are 6.

[0130] Table 3. Difference in adjacent measurement distances under multiple cycles of triangular wave modulated signal

[0131]

[0132] Among them, the pulse interval within a single pulse interval period of the triangular wave modulated signal is {t}. c -t d , t c , t c +t d , t c}, t c Preset center frequency pulse interval, t d The preset time interval and the preset number of pulse intervals are 4.

[0133] Table 4. Difference in adjacent measurement distances under different multi-cycle conditions of stepped wave modulated signal

[0134]

[0135] Among them, the pulse interval within a single pulse interval period of the stepped wave modulated signal is {t}. c -t d , t c -t d , t c , t c , t c +t d , t c +t d}, t c Preset center frequency pulse interval, t d The preset time interval and the preset number of pulse intervals are 6.

[0136] The following will continue to explain the target ranging device and detection equipment provided in any of the above embodiments of this application. The specific implementation process and the resulting technical effects are the same as those in the corresponding method embodiments. For the sake of brevity, the parts not mentioned in this embodiment can be referred to the corresponding content in the method embodiment.

[0137] Figure 8 This is a schematic diagram of the functional modules of a target ranging device provided in an embodiment of this application.

[0138] like Figure 8 As shown, the target ranging device 100 includes:

[0139] The modulation module 110 is used to periodically modulate the transmitted pulse with a preset modulation signal to obtain a transmitted pulse with a single pulse period, wherein the single pulse period includes: a transmitted pulse with multiple pulse intervals corresponding to the preset modulation signal;

[0140] The transceiver module 120 is used to sequentially transmit multiple pulses with multiple pulse intervals within a single pulse period, and sequentially receive multiple echo pulses reflected back by the target object under test.

[0141] The calculation module 130 is used to determine the measurement distance corresponding to multiple echo pulses based on the reception time of multiple echo pulses and the transmission time of the most recent transmission pulse of multiple echo pulses;

[0142] The calculation module 130 is also used to obtain a sequence of adjacent measurement distance differences in a single pulse period based on the measurement distances corresponding to multiple echo pulses;

[0143] The calculation module 130 is also used to find the sequence that is closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence, and to determine the target multi-period. The multi-period is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse. Each multi-period regular sequence records the adjacent measurement distance difference sequence pre-calculated under each multi-period.

[0144] The calculation module 130 is also used to obtain the actual distance of the target object to be measured based on the target multi-cycle and the measurement distance corresponding to the echo pulse.

[0145] Optionally, the calculation module 130 is also used to determine, from multiple multi-period regular sequences, the target regular sequence that is closest to the adjacent measurement distance difference sequence based on the adjacent measurement distance difference sequence; and to determine the multi-period corresponding to the target regular sequence as the target multi-period.

[0146] Optionally, the calculation module 130 is also used to determine the target regular sequence from multiple multi-period regular sequences based on the number of positive, negative and zero values ​​in the adjacent measurement distance difference sequence.

[0147] Optionally, the calculation module 130 is also used to determine the target regular sequence from multiple multi-period regular sequences based on the positive average value and / or negative average value in the adjacent measurement distance difference sequence, where the range of the average value is located.

[0148] Optionally, the calculation module 130 is also used to calculate the correlation coefficients of adjacent measurement distance difference sequences and multiple multi-period regular sequences respectively; and to determine the target regular sequence from the multiple multi-period regular sequences based on the correlation coefficients.

[0149] Optionally, the calculation module 130 is also used to calculate the cross-correlation coefficients of the adjacent measurement distance difference sequence and the multiple multi-period regular sequences respectively; and to determine the target regular sequence from the multiple multi-period regular sequences based on the cross-correlation coefficients.

[0150] Optionally, the calculation module 130 is also used to calculate the class correlation coefficient of the adjacent measurement distance difference sequence and multiple multi-period regular sequences; and to determine the target regular sequence from the multiple multi-period regular sequences based on the class correlation coefficient.

[0151] Optionally, the target ranging device 100 further includes:

[0152] The generation module is used to generate a preset modulation signal based on a preset center frequency pulse interval, a preset time interval, and a preset number of pulse intervals, using a preset waveform.

[0153] The above-described device is used to execute the method provided in the foregoing embodiments, and its implementation principle and technical effect are similar, so they will not be described again here.

[0154] These modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more microprocessors, or one or more Field Programmable Gate Arrays (FPGAs). Alternatively, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a system-on-a-chip (SOC).

[0155] This application also provides a schematic diagram of a detection device that can be used for target ranging. The detection device includes: a modulation module, a transceiver module, and a calculation module; wherein the modulation module is connected to the transceiver module, and the transceiver module is connected to the calculation module; the transceiver can be a fixed-point transceiver, such as a rangefinder, or a scanning transceiver, such as a lidar.

[0156] The modulation module is used to periodically modulate the transmitted pulse with a preset modulation signal to obtain a transmitted pulse with a single pulse period, wherein the single pulse period includes: a transmitted pulse with multiple pulse intervals corresponding to the preset modulation signal;

[0157] The transceiver module is used to sequentially transmit multiple pulses with multiple pulse intervals within a single pulse period, and sequentially receive multiple echo pulses reflected back by the target object under test.

[0158] The calculation module is used to determine the measurement distance corresponding to multiple echo pulses based on the reception time of multiple echo pulses and the transmission time of the nearest transmission pulse of multiple echo pulses;

[0159] The calculation module is also used to obtain a sequence of adjacent measurement distance differences for a single pulse cycle based on the measurement distances corresponding to multiple echo pulses.

[0160] The calculation module is also used to find the sequence that is closest to the adjacent measurement distance difference sequence from multiple multi-period regular sequences corresponding to the preset modulation signal based on the adjacent measurement distance difference sequence, and to determine the target multi-period. The multi-period is used to characterize the number of pulse intervals between the echo pulse and the corresponding transmitted pulse. Each multi-period regular sequence records the adjacent measurement distance difference sequence pre-calculated under each multi-period.

[0161] The calculation module is also used to obtain the actual distance of the target object under test based on the target's multi-cycle and the measurement distance corresponding to the echo pulse.

[0162] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0163] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0164] Furthermore, the functional units in the various embodiments of the present invention 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 in the form of hardware plus software functional units.

[0165] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0166] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for measuring the distance to a target object, characterized in that, The method comprises the following steps: periodically modulating the transmission pulse by using a preset modulation signal to obtain a transmission pulse in a single pulse period, wherein the single pulse period comprises transmission pulses in a plurality of pulse intervals corresponding to the preset modulation signal; transmitting the transmission pulses in the plurality of pulse intervals in the single pulse period in sequence and receiving a plurality of echo pulses reflected by the target object in sequence; determining a measurement distance corresponding to each of the plurality of echo pulses according to the receiving time of the echo pulse and the transmission time of the nearest transmission pulse of the echo pulse; obtaining a sequence of adjacent measurement distance difference values in the single pulse period according to the measurement distances corresponding to the plurality of echo pulses; determining a target multi-period from a plurality of multi-period regular sequences corresponding to the preset modulation signal according to the sequence of adjacent measurement distance difference values, wherein the multi-period is used to represent the number of pulse intervals between the echo pulse and the corresponding transmission pulse, and each multi-period regular sequence records a sequence of adjacent measurement distance difference values calculated in advance under the multi-period; obtaining the actual distance of the target object according to the target multi-period and the measurement distance corresponding to the echo pulse.

2. The method of claim 1, wherein, The method comprises the following steps: determining a target regular sequence from the plurality of multi-period regular sequences according to the sequence of adjacent measurement distance difference values, wherein the target regular sequence is the closest to the sequence of adjacent measurement distance difference values; determining the target multi-period as the multi-period corresponding to the target regular sequence.

3. The method of claim 2, wherein, The method comprises the following steps: determining the target regular sequence from the plurality of multi-period regular sequences according to the number of positive values, negative values and zero values in the sequence of adjacent measurement distance difference values, wherein the target regular sequence is the one with the same number of positive values, negative values and zero values.

4. The method of claim 2, wherein, The method comprises the following steps: determining the target regular sequence from the plurality of multi-period regular sequences according to the average value of positive values and / or the average value of negative values in the sequence of adjacent measurement distance difference values, wherein the target regular sequence is the one with the same range of average values.

5. The method of claim 2, wherein, The method comprises the following steps: calculating the correlation coefficients of the sequence of adjacent measurement distance difference values and the plurality of multi-period regular sequences respectively; determining the target regular sequence from the plurality of multi-period regular sequences according to the correlation coefficients.

6. The method of claim 5, wherein, The method comprises the following steps: respectively calculate the correlation coefficients of the adjacent measurement distance difference value sequence and the multiple periodic regular sequences; determine the target regular sequence from the multiple periodic regular sequences according to the cross-correlation coefficients.

7. The method of claim 5, wherein, The method further comprises the following steps before the step of modulating the transmission pulse with the preset modulation signal to obtain the transmission pulse of a single pulse period: generate the preset modulation signal by using a preset waveform according to a pulse interval of the preset central frequency, a preset time interval, and a preset pulse interval number. The method further comprises the following steps before the step of modulating the transmission pulse with the preset modulation signal to obtain the transmission pulse of a single pulse period:

8. The method according to any one of claims 1 to 7, characterized in that, modulation module, configured to periodically modulate the transmission pulse with a preset modulation signal to obtain the transmission pulse of a single pulse period, wherein the single pulse period comprises transmission pulses of multiple pulse intervals corresponding to the preset modulation signal; transceiver module, configured to sequentially transmit the transmission pulses of the multiple pulse intervals in the single pulse period and sequentially receive multiple echo pulses reflected back by the target object; 9. A ranging device for a target object, characterized by calculation module, configured to determine measurement distances corresponding to the multiple echo pulses according to reception times of the multiple echo pulses and transmission times of the closest transmission pulses of the multiple echo pulses; The calculation module is further configured to obtain an adjacent measurement distance difference value sequence of the single pulse period according to the measurement distances corresponding to the multiple echo pulses. The calculation module is further configured to find a target multiple period from multiple periodic regular sequences corresponding to the preset modulation signal according to the adjacent measurement distance difference value sequence, wherein the target multiple period is the closest sequence to the adjacent measurement distance difference value sequence, and a multiple period is used to represent a number of pulse intervals between an echo pulse and a corresponding transmission pulse, and each periodic regular sequence of the multiple periodic regular sequences records an adjacent measurement distance difference value sequence calculated in advance under each multiple period. The calculation module is further configured to obtain an actual distance of the target object according to the target multiple period and the measurement distances corresponding to the echo pulses. The detection device comprises a modulation module, a transceiver module, and a calculation module, wherein the modulation module is connected to the transceiver module, and the transceiver module is connected to the calculation module. The modulation module is configured to periodically modulate the transmission pulse with a preset modulation signal to obtain the transmission pulse of a single pulse period, wherein the single pulse period comprises transmission pulses of multiple pulse intervals corresponding to the preset modulation signal. The transceiver module is configured to sequentially transmit the transmission pulses of the multiple pulse intervals in the single pulse period and sequentially receive multiple echo pulses reflected back by the target object.

10. A detection device, characterized in that The calculation module is configured to determine measurement distances corresponding to the multiple echo pulses according to reception times of the multiple echo pulses and transmission times of the closest transmission pulses of the multiple echo pulses. The calculation module is further configured to obtain an adjacent measurement distance difference value sequence of the single pulse period according to the measurement distances corresponding to the multiple echo pulses. ​ ​ The computing module is further configured to obtain, according to the measured distances corresponding to the plurality of echo pulses a sequence of adjacent measured distance difference values of the single pulse period; The computing module is further configured to find, according to the sequence of adjacent measured distance difference values, a sequence closest to the sequence of adjacent measured distance difference values from a plurality of regular sequences of multiple periods corresponding to the preset modulation signal, to determine a target multiple period, wherein a multiple period is used to represent a number of pulse intervals between an echo pulse and a corresponding transmission pulse, and each regular sequence of multiple periods records a sequence of adjacent measured distance difference values pre-calculated under the each multiple period; The computing module is further configured to obtain the actual distance of the target object to be measured according to the target multiple period and the measured distances corresponding to the echo pulses.

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