Ultrasonic ranging method, ultrasonic ranging system, storage medium and program product

Abstract

The invention discloses an ultrasonic ranging method, an ultrasonic ranging system, a storage medium and a program product, and relates to the technical field of intelligent perception, and the method comprises the steps: a transmitting end generates a plurality of candidate sequence codes of time domain compression based on orthogonal code elements, the candidate sequence codes are generated by orthogonal code elements through at least one mode of time domain arrangement, code element interval adjustment, combined execution of random arrangement and code element interval adjustment, and then target sequence codes are selected from the candidate sequence codes and shared with a receiving end; broadcasting a target ultrasonic signal containing the target sequence code to a receiving end, and determining the distance to the receiving end after receiving the target ultrasonic signal returned by the receiving end; the receiving end receives at least one ultrasonic signal, when a target ultrasonic signal matched with the target sequence code is recognized, conflict detection is carried out on a transmission channel of the target ultrasonic signal, and if the current channel has no conflict or the conflict in the channels is solved, distance measurement is carried out on the receiving end and the sending end based on the target ultrasonic signal.

Description

Technical Field

[0001] This application relates to the field of intelligent sensing technology, and particularly to an ultrasonic ranging method, an ultrasonic ranging system, a storage medium, and a program product. Background Art

[0002] Due to the non-intercommunication of channel resource allocation information between distributed systems, channel conflicts often occur between multiple distributed systems under the condition of lacking centralized coordination, making it difficult to perform ranging between distributed systems efficiently and reliably in practical applications.

[0003] The existing technologies for solving channel conflicts are: carrier sensing mechanism, time slot reservation mechanism, and multiplexing technology. The carrier sensing mechanism is to continuously monitor the channel and send when it is idle, otherwise delay. Since the ultrasonic ranging signal is short burst and the listening period is long, the carrier sensing mechanism cannot adapt to ultrasonic ranging and conflicts will still occur. The time slot reservation mechanism needs to rely on a dedicated out-of-band negotiation channel for time slot pre-allocation, which is a kind of centralized coordination and violates the principle of distributed autonomy. The multiplexing technology includes time division multiplexing, frequency division multiplexing, and code division multiplexing. Among them, time division multiplexing requires centralized coordination and violates the principle of distributed autonomy; frequency division multiplexing has too narrow ultrasonic bandwidth and can only be divided into 4 sub-channels, and there will also be frequency shift caused by the Doppler effect, resulting in frequency band overlap; code division multiplexing uses pseudo-random sequences, but the number of encodings is limited and cannot meet the large-scale demand. In short, in the distributed ultrasonic ranging scenario, the existing technologies still face problems such as channel conflicts and are difficult to meet the needs of large-scale distributed systems.

[0004] The above content is only used to assist in understanding the technical solution of this application, and does not represent an admission that the above content is the prior art. Summary of the Invention

[0005] The main purpose of this application is to provide an ultrasonic ranging method, an ultrasonic ranging system, a storage medium, and a program product, aiming to solve the technical problem that the existing technology faces channel conflicts in the distributed ultrasonic ranging scenario and is difficult to meet the needs of large-scale distributed systems.

[0006] To achieve the above object, this application proposes an ultrasonic ranging method, which is applied to a sending end. The method includes: generating multiple candidate sequence encodings with time domain compression based on orthogonal code elements, where the generating multiple candidate sequence encodings with time domain compression based on orthogonal code elements includes at least one of the following methods: (a) randomly arranging the orthogonal code elements in the time domain to form a candidate sequence encoding; (b) adjusting the code element interval between adjacent code elements in the random arrangement result of the orthogonal code elements to form a candidate sequence encoding; (c) combining and performing random arrangement and adjustment of the code element interval between adjacent code elements to form a candidate sequence encoding; Select a target sequence code from multiple candidate sequence codes and share the target sequence code with the receiving end; Broadcast a target ultrasonic signal containing the target sequence code to the receiving end, receive the target ultrasonic signal returned by the receiving end, and determine the distance to the receiving end based on the target ultrasonic signal.

[0007] In one embodiment, the orthogonal code elements are signals that are orthogonal to each other in the frequency domain or code domain, and the orthogonal code elements include a first code element and a second code element.

[0008] To achieve the above object, the present application proposes an ultrasonic ranging method applied to the receiving end. The method includes: Receive at least one ultrasonic signal. When a target ultrasonic signal matching the target sequence code is recognized, perform conflict detection on the transmission channel of the target ultrasonic signal under multiple decisions. The target sequence code is selected from candidate sequence codes formed according to at least one of the following methods: (a) randomly permute the orthogonal code elements in the time domain; (b) adjust the code element interval between adjacent code elements in the random permutation result of the orthogonal code elements; (c) combine the execution of random permutation and adjustment of the code element interval between adjacent code elements. The target sequence code is pre-shared between the sending end and the receiving end. Conflicts include coverage conflict, congestion conflict, and channel conflict; If a conflict is detected, trigger a conflict resolution decision under the corresponding conflict; if no conflict is detected, perform ranging between the receiving end and the sending end based on the target ultrasonic signal.

[0009] In one embodiment, after the step of receiving at least one ultrasonic signal, the following steps are further included: If the target sequence code is not recognized in each ultrasonic signal, it is determined as a coverage conflict, and the sending end is notified to retransmit the target ultrasonic signal containing the target sequence code; The step of performing conflict detection on the transmission channel of the target ultrasonic signal under multiple decisions includes: If no coverage conflict occurs and the peak-to-average ratio of the target ultrasonic signal is lower than a preset peak-to-average ratio threshold, it is determined as a congestion conflict, and the sending end is notified to retransmit the target ultrasonic signal containing the target sequence code; If no congestion conflict occurs and the relative relationship between the time difference of arrival of the first target ultrasonic signal and the second target ultrasonic signal and the signal strength of the first target ultrasonic signal and the second target ultrasonic signal does not conform to the acoustic wave reflection law, it is determined as a channel conflict, and the sending end is notified to reselect the target sequence code and generate a new target ultrasonic signal for broadcasting.

[0010] In one embodiment, the orthogonal code elements include a first code element and a second code element. Before the step of performing ranging between the receiving end and the sending end of the ultrasonic signal based on the target ultrasonic signal, the following steps are further included: Identify the time-domain forward shift feature of the first symbol-related peak and the time-domain backward shift feature of the second symbol-related peak; According to the time-domain forward shift feature and the time-domain backward shift feature, calculate the Doppler frequency offset estimation amount at the relative moving speed of the transmitter and the receiver; Perform time delay compensation on the target ultrasonic signal according to the Doppler frequency offset estimation amount to eliminate the Doppler effect of the target ultrasonic signal.

[0011] In one embodiment, the step of ranging the receiver and transmitter of the ultrasonic signal based on the target ultrasonic signal includes: Obtain a first timestamp and a second timestamp when the transmitter sends the target ultrasonic signal, where the first timestamp is the first time when the transmitter records itself sending the target ultrasonic signal, and the second timestamp is the second time when the receiver records itself receiving the target ultrasonic signal; When returning the target ultrasonic signal to the transmitter, obtain a third timestamp and a fourth timestamp, where the third timestamp is the third time when the receiver records itself sending the target ultrasonic signal, and the fourth timestamp is the fourth time when the transmitter records itself receiving the target ultrasonic signal; Based on the first difference between the fourth timestamp and the first timestamp, and the second difference between the third timestamp and the second timestamp, calculate the propagation delay of the target ultrasonic signal; According to the propagation delay and the propagation speed of ultrasonic waves, obtain the distance between the receiver and the transmitter of the ultrasonic signal.

[0012] In one embodiment, the orthogonal code elements include a first code element and a second code element. After the step of receiving at least one ultrasonic signal, it includes: Perform filtering processing on the received ultrasonic signal to obtain a preprocessed ultrasonic signal; Calculate the first channel response curve of the preprocessed ultrasonic signal and the first code element and the second channel response curve of the second code element; Under the condition of eliminating the cross-correlation interference between the first channel response curve and the second channel response curve, based on the time-domain compressed symbol interval, search for a correlation peak combination that matches the time-domain distribution of the target sequence coding from the first channel response curve and the second channel response curve; According to the time-domain position and coding interval consistency of the correlation peak combination, determine the target ultrasonic signal that matches the time-domain characteristics of the target sequence coding.

[0013] In addition, to achieve the above object, the present application also proposes an ultrasonic ranging system, which includes a transmitting end and a receiving end. The transmitting end, and / or the receiving end, is configured to implement the steps of the ultrasonic ranging method as described above.

[0014] In addition, to achieve the above object, the present application also proposes a storage medium. The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the ultrasonic ranging method as described above.

[0015] In addition, to achieve the above object, the present application also provides a computer program product. The computer program product includes a computer program. When the computer program is executed by a processor, it implements the steps of the ultrasonic ranging method as described above.

[0016] One or more technical solutions proposed by the present application have at least the following technical effects: Existing conflict avoidance mechanisms (carrier sensing, slot reservation, multiplexing) have problems such as insufficient adaptability, dependence on centralized coordination, or limited coding resources in distributed scenarios, resulting in frequent channel conflicts.

[0017] The present application uses at least one of the following methods: (a) randomly arranging orthogonal code elements in the time domain; (b) adjusting the code element interval between adjacent code elements in the random arrangement result of orthogonal code elements; (c) combining the execution of random arrangement and adjustment of the code element interval between adjacent code elements to generate a large number of candidate sequence encodings. It can improve the code element density per unit time through time domain compression, enabling more orthogonal code element combinations to be arranged under the same code length. By adjusting the code element interval, the fixed code element interval limit is broken, further increasing the coding space dimension, significantly increasing the number of candidate sequence encodings, and reducing the probability of coding conflicts among multiple devices. The coding method mentioned in the present application allows devices to autonomously generate candidate sequence encodings without relying on global codebook allocation, adapts to distributed scenarios, and solves the technical problem that the prior art is difficult to meet the requirements of large-scale distributed scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0019] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1A schematic diagram of the existing channel conflict in this application; Figure 2 A schematic flowchart provided by an embodiment of the ultrasonic ranging method in this application; Figure 3 A schematic diagram without time-domain compression provided by an embodiment of the ultrasonic ranging method in this application; Figure 4 A schematic diagram after time-domain compression provided by an embodiment of the ultrasonic ranging method in this application; Figure 5 A schematic diagram of conflict detection and resolution provided by an embodiment of the ultrasonic ranging method in this application; Figure 6 A schematic diagram of the relevant peak shift provided by an embodiment of the ultrasonic ranging method in this application; Figure 7 A schematic diagram of ultrasonic signal processing provided by an embodiment of the ultrasonic ranging method in this application; Figure 8 A schematic diagram of the overall structure provided by an embodiment of the ultrasonic ranging method in this application.

[0021] The implementation, functional features, and advantages of the purpose of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Detailed implementation manners

[0022] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of this application and are not used to limit this application.

[0023] To better understand the technical solutions of this application, the following will be described in detail in conjunction with the accompanying drawings of the specification and specific implementation manners.

[0024] In the context of the rapid development of the Internet of Things and pervasive computing, multi-device distributed coordinated ultrasonic ranging systems are becoming an important research direction in the field of intelligent perception. Compared with the centralized architecture that relies on a central control node, the distributed coordinated system can better adapt to the dynamic open environment through device autonomous decision-making and local coordination, and demonstrates unique application advantages in complex scenarios.

[0025] For example, in an augmented reality scenario, when the headset devices worn by multiple users construct a spatial awareness network through ultrasonic signals with a remote control, since it is difficult for the headset devices to rely on a single central node for centralized coordination, multiple independent distributed ranging subsystems are likely to be formed; in an enterprise office scenario, when multiple terminal devices with user status recognition functions based on ranging are operating, due to the lack of cross-system coordination capabilities, they can only rely on local decision-making to complete the recognition tasks; in a medical monitoring scenario, multiple mobile medical devices establish distance links with the smart terminals of different users to achieve user tracking. Most of the time, due to characteristics such as high device density, strong environmental dynamics, and resource constraints in these scenarios, centralized coordination cannot be carried out among multiple distributed systems within the scenario.

[0026] Without relying on global coordination, achieving efficient and reliable distributed ranging lies in how to avoid channel conflicts among distributed systems as much as possible. Channel conflicts occur because the channel resource allocation information among distributed systems is not interoperable and under the condition of lacking centralized coordination, that is, multiple distributed systems select the same coded signal and cannot distinguish each other. At this time, incorrect distance calculations will occur due to the inability to identify the signal source.

[0027] The traditional carrier sense mechanism is a classic conflict avoidance scheme. The core principle is to continuously sense the channel state and detect whether the channel is idle before a node (receiver or transmitter) sends data: if the channel is idle, the signal is sent immediately; if the channel is detected to be occupied, a random backoff delay mechanism is started to avoid conflicts. However, the fixed sensing period of the traditional carrier sense mechanism, which can be several seconds or even dozens of seconds, is difficult to adapt to the instantaneous transmission characteristics of ultrasonic ranging pulses.

[0028] The time slot reservation mechanism is another existing conflict avoidance scheme. It relies on a dedicated out-of-band negotiation channel and is a centralized pre-allocation mode. However, this centralized pre-allocation mode fundamentally conflicts with the core principles of autonomous decision-making and local coordination of distributed systems.

[0029] The above traditional conflict avoidance mechanisms are neither suitable for the short-time and instantaneous characteristics of ultrasonic signals nor in line with the principle of autonomous coordination of distributed systems.

[0030] Therefore, adopting a multi-channel coding scheme has become a key way to reduce the collision probability. Although multiplexing technologies (time-division multiplexing technology, frequency-division multiplexing technology, code-division multiplexing technology) can achieve parallel transmission of multiple ultrasonic signals, there are still limitations. Among them, time-division multiplexing technology relies on strict time slice allocation, and this allocation mechanism requires centralized coordination, which violates the autonomy principle of distributed systems; although frequency-division multiplexing technology uses the available frequency band of 18 kHz - 24 kHz to divide orthogonal sub-channels, limited by the narrow bandwidth, the number of actual supported orthogonal sub-channels does not exceed 4, and the environmental Doppler effect will cause sub-carrier offset, resulting in frequency band overlap and further reducing the channel isolation degree; code-division multiplexing technology distinguishes devices based on pseudo-random sequences. Due to the pseudo-orthogonality of the modulation signals, the number of available codes is still limited, making it difficult to meet the requirements of large-scale distributed scenarios.

[0031] As Figure 1 shown, Figure 1 Fig. shows an existing case of channel conflict. In the same space, Device 1 and Device 2 are performing ranging, and at the same time, Device 3 and Device 4 are also performing ranging, but the two groups of ranging devices are unaware of each other, that is, Device 1 and Device 2 are not aware that Device 3 and Device 4 are also performing ranging. In one case, when Device 1 and Device 2, and Device 3 and Device 4, perform ranging, they select the same or similar coded signals, that is, as Figure 1 shown, Device 1 receives the signal sent by Device 4 or Device 3 receives the signal sent by Device 2; in this case of conflict, the device will calculate the wrong distance because it cannot distinguish the signal source.

[0032] To solve the above problems, this application proposes an ultrasonic ranging method: According to at least one of the following methods: (a) randomly arranging orthogonal code elements in the time domain; (b) adjusting the code element interval between adjacent code elements in the random arrangement result of orthogonal code elements; (c) combining the execution of random arrangement and adjustment of the code element interval between adjacent code elements to generate a large number of candidate sequence codes, greatly increasing the ranging signal selection space of the distributed system and largely avoiding signal collisions between distributed systems (both the sending end and the receiving end can be regarded as a distributed system); the receiving end performs precise conflict suppression through conflict detection to achieve anti-collision distributed ranging.

[0033] It should be noted that the execution subject of this embodiment can be an ultrasonic ranging system, or a computing service device with data processing, network communication, and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, a processor, etc. that can implement the above functions. Hereinafter, the ultrasonic ranging system will be taken as an example to illustrate this embodiment and the following embodiments.

[0034] Based on this, an embodiment of the present application provides an ultrasonic ranging method. Referring to Figure 2 , Figure 2 is a schematic flowchart of an embodiment of the ultrasonic ranging method of the present application.

[0035] In this embodiment, the ultrasonic ranging method includes steps S10 to S30: Step S10, generating multiple candidate sequence encodings with time-domain compression based on orthogonal code elements. Among them, generating multiple candidate sequence encodings with time-domain compression based on orthogonal code elements includes at least one of the following methods: (a) randomly arranging the orthogonal code elements in the time domain to form candidate sequence encodings; (b) adjusting the code element interval between adjacent code elements in the random arrangement result of the orthogonal code elements to form candidate sequence encodings; (c) combining the execution of random arrangement and the adjustment of the code element interval between adjacent code elements to form candidate sequence encodings; It should be noted that orthogonal code elements refer to a group of basic signal units with non-interfering characteristics. Time-domain compression means that by shortening the code element interval between adjacent code elements, multiple code elements are compressed and transmitted in a shorter time.

[0036] The generation method of the candidate sequence encoding is: passing the orthogonal code elements through operations such as repetition and replacement in a specific or random order. In this embodiment, the arrangement method of the orthogonal code elements is not limited, and an encoding sequence with different time-domain structures is formed. For example, if the orthogonal code elements are selected as 0 / 1, one arrangement result can be: 11001010; in the arranged code element sequence, the code element interval between adjacent code elements can also be adjusted, set to be uniform or non-uniform. For example, the sequence encoding with adjusted code element interval can be: 1__1__0_0__1__0__1__0.

[0037] Exemplarily, multiple candidate sequence encodings can be generated by only randomly arranging the orthogonal code elements in the time domain, or multiple candidate sequence encodings can be generated by only adjusting the code element interval between adjacent code elements; multiple candidate sequence encodings can also be generated by both randomly arranging in the time domain and adjusting the code element interval between adjacent code elements. In this embodiment, the method of generating candidate sequence encodings is not limited.

[0038] As Figure 3 shown, Figure 3 shows a sequence encoding without time-domain compression. As Figure 4 shown, Figure 4 shows the sequence encoding with time-domain compression. By comparison, it can be seen that compressing multiple code elements and transmitting them in a shorter time can improve the signal transmission efficiency. By compressing multiple code elements in the time domain, the generated sequence encoding will not exceed two code element signals in length, while the information transmission ability remains. Through experiments, although the compression in time brings a decrease in the transmission energy of a single code element, the overall signal quality does not significantly decline.

[0039] It can be understood that in step S10, a large number of candidate codes are generated by flexible arrangement and interval adjustment, providing a basis for subsequent selection of the target sequence code, thereby reducing the probability of signal conflict between multiple devices.

[0040] In step S20, a target sequence code is selected from multiple candidate sequence codes, and the target sequence code is shared with the receiving end; It should be noted that the sending end randomly selects a target sequence code from the candidate code library. After selection, the target sequence code is shared with the receiving end. Exemplarily, the code sharing with the receiving end can be completed in the following ways: using low-frequency wireless communication to pre-transmit the arrangement rules, interval patterns, etc. of the target code, and it is also possible to generate a consistent target sequence code based on an encryption algorithm in an encrypted channel to achieve decentralized coordinated code synchronization.

[0041] It can be understood that in step S20, it is ensured that the sending end and the receiving end reach a consensus on the uniqueness of the target code in a distributed scenario, avoiding ranging failure caused by coding mis-matching.

[0042] In step S30, a target ultrasonic signal containing the target sequence code is broadcast to the receiving end, the target ultrasonic signal returned by the receiving end is received, and the distance to the receiving end is determined based on the target ultrasonic signal.

[0043] It should be noted that the sending end converts the target sequence code into a target ultrasonic signal and broadcasts it. Among them, the uniqueness of the target code can filter out interference signals from other devices and ensure ranging accuracy. After the sending end receives the target ultrasonic signal returned by the receiving end, the distance to the receiving end can be determined based on the time stamp of the target ultrasonic signal. For specific ranging methods, see the embodiments of the receiving end.

[0044] It can be understood that in step S30, by encoding and broadcasting ultrasonic signals, accurate ranging in a distributed environment can be achieved, while being compatible with multi-device cooperation in dynamic scenarios.

[0045] In a feasible implementation manner, the orthogonal code elements are signals that are orthogonal to each other in the frequency domain or code domain. When the orthogonal code elements are orthogonal to each other in the code domain, the code division multiplexing method can be used, and relatively classic code division signals in the field of communication or signal processing, such as ZC sequences, pseudo-random sequences, linear frequency modulation signals, etc., can be adopted.

[0046] It should be noted that since the current multiplexing technology supports relatively few channel selections for ultrasonic signals, relying solely on traditional multiplexing technology cannot meet the requirement of avoiding channel conflicts as much as possible in the distributed concurrent ranging scenario. Based on the problems existing in the prior art, the present application designs the symbol through operations such as repetition and replacement in the time domain, and the present application also takes into account the selection of symbols. Since it is desired that the symbol has sufficient bandwidth to cope with the complex signal transmission environment, the symbol generally selects a signal with strong self-correlation and weak cross-correlation that supports code division multiplexing technology, that is, it has orthogonal characteristics.

[0047] The orthogonal symbols with orthogonal characteristics include two symbols (the first symbol and the second symbol), which means that when selecting orthogonal symbols, two symbols can be selected, one symbol can be selected, or more than two symbols can be selected, and the number of selected symbols is not limited. The time-frequency change trajectories of the first symbol and the second symbol are mirror images of each other, so that the integral result after multiplying the two symbol signals in the time domain approaches zero, thereby realizing strong distinguishability between signals. This orthogonal characteristic enables the receiving end to accurately separate the two symbols through matched filtering, significantly improving the anti-interference ability and multipath suppression effect of multi-device parallel communication in ultrasonic ranging.

[0048] In this embodiment, through at least one of the following methods: (a) randomly arranging the orthogonal symbols in the time domain; (b) adjusting the symbol interval between adjacent symbols in the random arrangement result of the orthogonal symbols; (c) combining the execution of random arrangement and adjustment of the symbol interval between adjacent symbols to generate a large number of candidate sequence encodings, breaking through the traditional code division multiplexing coding quantity limit, and greatly reducing the channel conflict probability; by randomly selecting the target sequence encoding and synchronizing it with the receiving end in advance, a decentralized coding allocation is realized, avoiding the resource overhead of centralized coordination, and at the same time ensuring coding differentiation between different systems. Based on the above embodiments of the present application, in another embodiment of the present application, the same or similar content as the above embodiments can be referred to the above introduction and will not be repeated hereinafter. The ultrasonic ranging method further includes steps D10 to D20: Step D10, receiving at least one ultrasonic signal, and when identifying a target ultrasonic signal that matches the target sequence encoding, performing conflict detection on the transmission channel of the target ultrasonic signal under multiple decisions, where the target sequence encoding is selected from the candidate sequence encodings formed by at least one of the following methods: (a) randomly arranging the orthogonal symbols in the time domain; (b) adjusting the symbol interval between adjacent symbols in the random arrangement result of the orthogonal symbols; (c) combining the execution of random arrangement and adjustment of the symbol interval between adjacent symbols, and the sending end and the receiving end share the target sequence encoding in advance, and the conflicts include coverage conflict, congestion conflict, and channel conflict; It should be noted that after the receiving end captures at least one ultrasonic signal, it first identifies the matching target ultrasonic signal from multiple ultrasonic signals through the target sequence coding shared with the transmitting end in advance, and then performs collision detection on the transmission channel of the target ultrasonic signal under multiple decisions; among them, the target sequence coding is generated by at least one of the following methods: arranging orthogonal code elements in the time domain, adjusting the interval between adjacent code elements, combining and performing random permutation and adjusting the code element interval between adjacent code elements; the collision types include coverage collision, congestion collision, and channel collision. Coverage collision means that due to too strong interference or the transmitting end missing a transmission, the receiving end cannot detect the target ultrasonic signal; congestion collision means that due to the complex environment, there are many distributed subsystems for concurrent ranging, the signal transmission conditions are poor, and the signal receiving end misidentifies the target sequence coding; channel collision means that different distributed subsystems simultaneously select the same sequence coding and broadcast signals simultaneously in a short time, and the receiving end cannot identify the target ultrasonic signal transmitted by the transmitting end, and the multipath characteristics of the signal do not conform to the law of acoustic wave reflection.

[0049] In a feasible implementation manner, after the step of receiving at least one ultrasonic signal in step D10, the following steps are further included: If the target sequence coding is not identified in each ultrasonic signal, it is determined as a coverage collision, and the transmitting end is notified to retransmit the target ultrasonic signal including the target sequence coding.

[0050] It should be noted that when the receiving end does not detect the target sequence coding in all the received ultrasonic signals (that is, the target ultrasonic signal that conforms to the target sequence coding cannot be identified through matched filtering), it is determined as a coverage collision. At this time, the receiving end immediately sends a retransmission instruction to the transmitting end, requesting the transmitting end to retransmit the target ultrasonic signal.

[0051] Step D10, the step of performing collision detection on the transmission channel of the target ultrasonic signal under multiple decisions, includes steps E10 to E20: Step E10, if there is no coverage collision and the peak-to-average ratio of the target ultrasonic signal is lower than a preset peak-to-average ratio threshold, it is determined as a congestion collision, and the transmitting end is notified to retransmit the target ultrasonic signal including the target sequence coding; It should be noted that when there is no coverage collision, if the peak-to-average ratio of the target ultrasonic signal (the ratio between the maximum value, i.e., the peak value, and the average value of the ultrasonic signal) is detected to be lower than the preset threshold, it is determined as a congestion collision. A low peak-to-average ratio indicates that there are multiple device co-frequency signals superimposed in the channel, resulting in waveform distortion and a sharp drop in the signal-to-noise ratio. At this time, the receiving end notifies the transmitting end to retransmit the target ultrasonic signal with a random time delay to reduce the probability of channel congestion by dispersing the signal transmission time.

[0052] Step E20: If no congestion conflict occurs and the relative relationship between the time difference of arrival of the first target ultrasonic signal and the second target ultrasonic signal and the signal intensities of the first target ultrasonic signal and the second target ultrasonic signal does not conform to the law of acoustic wave reflection, it is determined as a channel conflict, and the sending end is notified to reselect the target sequence coding and generate a new target ultrasonic signal for broadcasting.

[0053] It should be noted that when no congestion conflict occurs, if it is detected that the relative relationship between the time difference of arrival of the first target ultrasonic signal and the second target ultrasonic signal and the signal intensities deviates from the law of acoustic wave reflection, it is determined as a channel conflict; Among them, the first target ultrasonic signal can be the signal that directly reaches the receiving end without passing through an obstacle, with a short propagation time and high signal intensity. The second target ultrasonic signal can be the signal that reaches the receiving end after being reflected by an obstacle, with a long propagation time and low signal intensity. In an ideal environment, the relative relationship between the time difference of arrival and the signal intensity should satisfy: the time difference is proportional to the path difference; the signal intensity is inversely proportional to the path length.

[0054] The relative relationship between the signal intensities of the first target ultrasonic signal and the second target ultrasonic signal does not conform to the law of acoustic wave reflection: it can be that the time difference of arrival of the two target ultrasonic signals is large, but the difference in signal intensities of the two target ultrasonic signals is small; or it can be that the difference in signal intensities of the two target ultrasonic signals is significant, but the time difference of arrival of the two target ultrasonic signals does not conform to the calculated value of the speed of sound.

[0055] For example: The time difference of arrival ΔT of two target ultrasonic signals is small, but the difference in signal intensity ΔR of the target ultrasonic signals is large, violating the physical law that "the greater the distance, the greater the attenuation and the longer the propagation time", and it is determined as a channel conflict.

[0056] Such conflicts are mainly caused by the multipath effect (such as false paths generated by acoustic waves reflected by walls). The receiving end notifies the sending end to change the target sequence coding (such as switching the time-domain compression mode or the interval arrangement rule). By regenerating the orthogonal code element arrangement or adjusting the code element interval, the channel occupancy conflict is avoided, thereby restoring the channel reliability.

[0057] Exemplarily, as Figure 5 shown, Figure 5 shows a schematic diagram of conflict detection and conflict resolution. After receiving at least one ultrasonic signal, the receiving end performs conflict detection. First, it detects whether there is a coverage conflict. If there is a coverage conflict, it notifies the sending end to retransmit the target ultrasonic signal with a random time delay; then it detects whether there is a congestion conflict. If there is a congestion conflict, it notifies the sending end to retransmit the target ultrasonic signal with a random time delay; then it detects whether there is a channel conflict. If there is a channel conflict, it notifies the sending end to reselect the target sequence coding and generate a new target ultrasonic signal; if no conflict is detected, it calculates the distance between the sending end and the receiving end and outputs the distance value.

[0058] In this embodiment, when the target sequence code is not recognized at all, it is determined that the environmental noise or strong interference covers, triggering the signal retransmission mechanism to avoid ranging failure caused by the loss of the target ultrasonic signal; when the target ultrasonic signal exists but the peak-to-average ratio is lower than the threshold, it is determined that the channel congestion is caused by multi-device concurrency, and the signal transmission is dispersed by random delay retransmission to reduce the signal superposition interference; when the relationship between the time difference of arrival and the intensity of the target ultrasonic signal is abnormal, it is determined that the code is repeated or illegally occupied, and the channel conflict is avoided by replacing the target sequence code to ensure the uniqueness of the code; through the hierarchical conflict detection and conflict response mechanism, the conflicts that are prone to occur are resolved first, reducing unnecessary code switching overhead; significantly improving the reliability and adaptability of the distributed ultrasonic ranging system.

[0059] Step D20, if a conflict is detected, trigger the conflict resolution decision under the corresponding conflict; if no conflict is detected, perform ranging on the receiving end and the sending end based on the target ultrasonic signal.

[0060] It should be noted that after the conflict detection, if there is no conflict in the current channel or the conflict in the channel is resolved, ranging is performed on the receiving end and the sending end based on the target ultrasonic signal.

[0061] In this embodiment, the target sequence code generated based on the time-domain arrangement and interval adjustment of orthogonal code elements reduces the probability of channel conflict between multiple devices; through the determination logic covering conflict, congestion conflict, and channel conflict, conflicts are accurately identified and differentiated conflict resolution strategies are triggered to achieve decentralized autonomous coordination.

[0062] The Doppler effect refers to the fact that when there is relative motion between the sending end, that is, the sending device, and the receiving end, that is, the receiving device, the frequency of the received ultrasonic signal will change. Specifically, when the sending device moves towards the receiving device, the received signal frequency will be higher than the transmitting frequency; conversely, when the sending device moves away from the receiving device, the received signal frequency will be lower than the transmitting frequency. This frequency shift can be expressed as: ; where is the signal frequency of the transmitted ultrasonic signal, is the signal frequency of the received ultrasonic signal, is the propagation speed of sound waves in the medium, is the moving speed of the receiving device, is the moving speed of the sending device.

[0063] Since the frequency shift will introduce an additional channel response shift, reducing the accuracy of ranging that depends on the signal propagation time, the Doppler effect will cause serious ranging errors in the ranging of sound signals.

[0064] The traditional Doppler effect cancellation method calculates the frequency offset amplitude or the device movement speed using multi-dimensional information and compensates the received signal, which will bring additional system overhead.

[0065] This application proposes a new Doppler effect cancellation method. In a feasible implementation manner, before step D20, it includes steps G10 to G30: Step G10, identify the time-domain forward shift feature of the first symbol correlation peak and the time-domain backward shift feature of the second symbol correlation peak; It should be noted that when the transmitter and the receiver are relatively close to each other, the Doppler effect causes the signal wavelength to be compressed and the received signal frequency to increase. The first symbol correlation peak shows a forward shift in the time domain (the peak appearance time is earlier than expected); when the transmitter and the receiver are relatively far away from each other, the Doppler effect causes the signal wavelength to be stretched and the received signal frequency to decrease. The second symbol correlation peak shows a backward shift in the time domain (the peak appearance time is later than expected). Since the first symbol and the second symbol have orthogonal characteristics, the time-domain offset directions caused by their Doppler frequency offsets are also opposite. As Figure 6 shown, it shows the correlation peak offsets generated by these two symbol signals under the interference of the Doppler effect at different speeds. The left side is the first symbol, and its correlation peak shows a forward shift in the time domain; the right side is the second symbol, and its correlation peak shows a backward shift in the time domain.

[0066] It can be understood that in step G10, by comparing the time-domain offset directions of the two symbols, complementary information is provided for Doppler frequency offset estimation, avoiding misjudgment of the single signal offset direction.

[0067] Step G20, calculate the Doppler frequency offset estimation amount at the relative moving speed of the transmitter and the receiver according to the time-domain forward shift feature and the time-domain backward shift feature; It should be noted that by using the characteristics that the autocorrelation peak offsets shown by two orthogonal symbols for the same speed are fixed and independent, the Doppler frequency offset estimation amount is calculated without relying on external sensors or complex motion models, reducing the calculation complexity.

[0068] Step G30, perform time delay compensation on the target ultrasonic signal according to the Doppler frequency offset estimation amount to eliminate the Doppler effect of the target ultrasonic signal.

[0069] It should be noted that the time delay deviation of the target ultrasonic signal propagation caused by device movement is eliminated through the Doppler frequency offset estimation amount.

[0070] In this embodiment, by utilizing the time-domain forward shift feature of the first symbol correlation peak and the time-domain backward shift feature of the second symbol correlation peak, the Doppler frequency offset estimation quantity is calculated through the difference between the time shifts of the two, overcoming the estimation error caused by a single signal offset direction. Then, based on the Doppler frequency offset estimation quantity, the propagation delay of the ultrasonic signal is corrected to eliminate the Doppler effect caused by the relative movement of the devices, so as to eliminate the ranging deviation caused by the coding recognition error resulting from the Doppler effect. Moreover, in this application, the autocorrelation peak offsets exhibited by two orthogonal symbols for the same speed have fixed and independent characteristics, and the Doppler frequency offset estimation quantity is calculated without relying on external sensors or complex motion models, which can reduce the computational complexity.

[0071] In another embodiment, step D20 includes: Obtain the first timestamp and the second timestamp when the transmitting end sends the target ultrasonic signal. Among them, the first timestamp is the first time when the transmitting end records its own sending of the target ultrasonic signal, and the second timestamp is the second time when the receiving end records its own reception of the target ultrasonic signal; When returning the target ultrasonic signal to the transmitting end, obtain the third timestamp and the fourth timestamp. Among them, the third timestamp is the third time when the receiving end records its own sending of the target ultrasonic signal, and the fourth timestamp is the fourth time when the transmitting end records its own reception of the target ultrasonic signal; Based on the first difference between the fourth timestamp and the first timestamp, and the second difference between the third timestamp and the second timestamp, calculate the propagation delay of the target ultrasonic signal; According to the propagation delay and the propagation speed of the ultrasonic wave, obtain the distance between the receiving end and the transmitting end of the ultrasonic signal.

[0072] It should be noted that the first timestamp (denoted as T1): the moment when the transmitting end records its own sending of the target ultrasonic signal; the second timestamp (denoted as T2): the moment when the receiving end records its own reception of the signal. The third timestamp (denoted as T3): the moment when the receiving end records its own sending of the reply signal (i.e., returning the target ultrasonic signal), and the fourth timestamp (denoted as T4): the moment when the transmitting end records its own reception of the target ultrasonic signal.

[0073] The first difference: the total time for the transmitting end to send and receive the target ultrasonic signal (T4 - T1); the second difference: the local time for the receiving end to process the signal (T3 - T2).

[0074] Propagation delay ; the distance between the receiving end and the transmitting end of the ultrasonic signal : , where v is the propagation speed of the ultrasonic wave (about 343 m / s at room temperature).

[0075] In this embodiment, the accuracy and reliability of ultrasonic ranging are significantly improved through a two-way timestamp interaction mechanism and precise propagation delay calculation.

[0076] In yet another embodiment, step D10 includes: Filter the received ultrasonic signal to obtain a preprocessed ultrasonic signal; Calculate the first channel response curve of the preprocessed ultrasonic signal with the first symbol and the second channel response curve of the second symbol; Under the condition of eliminating the cross-correlation interference between the first channel response curve and the second channel response curve, based on the symbol interval after time-domain compression, search for a combination of correlation peaks that matches the time-domain distribution of the target sequence coding from the first channel response curve and the second channel response curve; Determine the target ultrasonic signal that matches the time-domain characteristics of the target sequence coding according to the time-domain position of the correlation peak combination and the coding interval consistency.

[0077] It should be noted that due to the presence of noise during signal transmission and the cross-correlation interference between mutually orthogonal symbols, the receiving end will first pass the received ultrasonic signal through a high-pass filter to remove the interference noise outside most of the signal frequency bands. Exemplarily, the cut-off frequency of the high-pass filter can be set to 16 kHz.

[0078] To extract the target sequence coding from the received ultrasonic signal, it is necessary to extract the channel characteristics of different symbol signals from the preprocessed ultrasonic signal. Calculate the correlation results of the received signal with a pair of symbol signals respectively, and then identify the signal that matches the target sequence coding in these two sets of correlation results. Since the pair of symbol signals we selected are mutually orthogonal, in the correlation results, the positions of the symbols can be found by searching for the correlation peaks respectively. For example, symbol 1 has correlation peaks at t1, t3, t5, t6, and symbol 0 has correlation peaks at t2, t4, t7. These two sets of correlation peaks can also be called two sets of correlation results, and the finally obtained sequence coding is 1010110.

[0079] However, when there are multiple unknown distributed systems in the environment that emit multiple sequence coding signals at unknown times with unknown intensities, there will be a considerable amount of cross-correlation interference between different symbols. Therefore, it is also necessary to use an interference cancellation algorithm to greatly suppress the cross-correlation interference.

[0080] As Figure 7 shown, first obtain the correlation results of different symbols to obtain two sets of correlation results; then perform interference cancellation on the two sets of correlation results to make the correlation peaks of the symbol signals more prominent.

[0081] After filtering and interference cancellation, the channel response curves of two symbol signals are obtained to get the first channel response curve and the second channel response curve. Then, the two channel response curves are replaced by the position arrays of the relevant peaks in the curves. Finally, the relevant peak combination of the optimal matching target ultrasonic signal is searched in the two arrays composed of the time domain coordinates of the relevant peaks, so as to find the target ultrasonic signal that matches the time domain characteristics of the target sequence coding.

[0082] Exemplarily, the existing search method is to adopt a complete traversal. However, this scheme needs to traverse all nodes in the array for the detection of any symbol. When the sequence coding length is k, it has a time complexity of O(kmn), and a large amount of time delay may be generated in a complex environment.

[0083] To optimize the time complexity, the search method adopted in this application is as follows: Based on the characteristic that the candidate coordinate arrays of two symbols are increasing, the binary search algorithm is used. First, each element of array A is traversed in ascending order. For each candidate array element A[i], the sequence coding C (C consists of 0 and 1) is traversed again. The algorithm will determine in which candidate array to perform the confidence determination according to the value of C[n]. Next, the binary search is used to find the first candidate coordinate greater than or equal to the theoretical coordinate of the symbol, and it is checked whether the candidate coordinate is within the ambiguity range, so as to determine whether the symbol is successfully matched. For each successfully matched symbol, 1 will be added to the confidence of the virtual signal starting with A[i]. At the end of traversing each element of A, it is judged whether to update the optimal result according to the confidence, and finally the ultrasonic signal with the highest confidence (using the earliest priority principle when the confidences are equal) is selected as the target ultrasonic signal.

[0084] It can be understood that since the target sequence coding includes two dimensions when it is formed, one is composed of the compression of multiple symbol signals in the time dimension, and the other includes the symbol intervals between multiple symbol signals. At the receiving end, only when the symbol signals of the ultrasonic signal are consistent in both dimensions, it is regarded as a successful match, that is, the target ultrasonic signal is successfully found.

[0085] In this embodiment, the low-frequency noise is effectively filtered through the filtering process to improve the signal-to-noise ratio of the received signal. Then, the channel response curves of the first symbol and the second symbol are calculated respectively through the cross-correlation algorithm, and the cross-correlation interference is suppressed by combining the interference cancellation algorithm to ensure that the relevant peaks are significantly prominent. Based on the symbol interval characteristics after time domain compression, the relevant peak combination that strictly matches the time domain distribution of the target sequence coding is searched in the channel response curve, and the matching rate of the target ultrasonic signal is improved through the double verification of the time domain position deviation and the coding interval consistency. Through multi-level signal processing and anti-interference design, the signal recognition accuracy and anti-environment interference ability of the ultrasonic ranging system are significantly improved.

[0086] Exemplarily, to facilitate understanding of the implementation process of the ultrasonic ranging method obtained by combining this embodiment with the above embodiments, please refer to Figure 8 , Figure 8 which provides a schematic diagram of the overall structure of an ultrasonic ranging method. Specifically: Both the mobile phone and the laptop can be either the transmitter or the receiver. The transmitter generates a target ultrasonic signal carrying a target sequence code, where the target sequence code is generated by at least one of the following ways: arranging orthogonal code elements in the time domain, adjusting the interval between adjacent code elements, combining and performing random permutation, and adjusting the code element interval between adjacent code elements, and has uniqueness and anti-interference characteristics. A device-to-device communication link is used between the transmitter and the receiver to synchronize the target sequence code in real time. When the ultrasonic signal carrying the target sequence code from the transmitter is broadcast to the receiver, the receiver receives and processes the signal, and matches the processed signal with the target sequence code. If the sequence codes match exactly and there is no conflict, the distance between the receiver and the transmitter of the ultrasonic signal is directly calculated and the distance value is output. If a conflict is detected, the conflict determination logic is used to accurately identify the conflict and trigger a differential conflict resolution strategy to achieve decentralized autonomous coordination.

[0087] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the ultrasonic ranging method of this application. Based on this technical concept, more forms of simple transformations, such as the interaction and combination of each embodiment, are within the protection scope of this application.

[0088] This application provides a computer-readable storage medium with computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the ultrasonic ranging method in the above embodiments.

[0089] The computer-readable storage medium provided by this application can be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) or flash memory, optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In this embodiment, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system or device. The program code contained on the computer-readable storage medium can be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination of the above.

[0090] The computer program code for performing the operations of this application can be written in one or more programming languages or combinations thereof. The above programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, executed as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, by using an Internet service provider to connect through the Internet).

[0091] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0092] The modules described in the embodiments of the present application can be implemented in software or in hardware. Among them, the name of the module does not constitute a limitation on the unit itself in some cases.

[0093] The readable storage medium provided by the present application is a computer-readable storage medium, and the computer-readable storage medium stores computer-readable program instructions (i.e., computer programs) for executing the above ultrasonic ranging method, which can solve the technical problem that the prior art faces channel conflicts in the distributed ultrasonic ranging scenario and is difficult to meet the requirements of large-scale distributed systems. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present application are the same as those of the ultrasonic ranging method provided by the above embodiments, and will not be elaborated here.

[0094] The present application also provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the steps of the ultrasonic ranging method as described above.

[0095] The computer program product provided by the present application can solve the technical problem that the prior art faces channel conflicts in the distributed ultrasonic ranging scenario and is difficult to meet the requirements of large-scale distributed systems. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as those of the ultrasonic ranging method provided by the above embodiments, and will not be elaborated here.

[0096] The above are only some embodiments of the present application, and thus do not limit the patent scope of the present application. Any equivalent structural transformation made under the technical concept of the present application by using the content of the specification and drawings of the present application, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present application.

Claims

1. An ultrasonic ranging method, characterized in that, Applied to the transmitting end, the ultrasonic ranging method includes: Generating multiple candidate sequence encodings with time-domain compression based on orthogonal code elements, where generating multiple candidate sequence encodings with time-domain compression based on orthogonal code elements includes at least one of the following methods: (a) randomly arranging the orthogonal code elements in the time domain to form a candidate sequence encoding; (b) adjusting the symbol interval between adjacent symbols in the random arrangement result of the orthogonal code elements to form a candidate sequence encoding; (c) combining the execution of random arrangement and symbol interval adjustment between adjacent symbols to form a candidate sequence encoding; Selecting a target sequence encoding from multiple candidate sequence encodings and sharing the target sequence encoding with the receiving end; Broadcasting a target ultrasonic signal containing the target sequence encoding to the receiving end, receiving the target ultrasonic signal returned by the receiving end, and determining the distance to the receiving end based on the target ultrasonic signal.

2. The method according to claim 1, wherein The orthogonal code elements are signals that are orthogonal to each other in the frequency domain or code domain, and the orthogonal code elements include a first code element and a second code element.

3. An ultrasonic ranging method, characterized in that, Applied to the receiving end, the ultrasonic ranging method includes: Receiving at least one ultrasonic signal, and when identifying a target ultrasonic signal that matches the target sequence encoding, performing conflict detection on the transmission channel of the target ultrasonic signal under multiple decisions, where the target sequence encoding is selected from candidate sequence encodings formed by at least one of the following methods: (a) randomly arranging orthogonal code elements in the time domain; (b) adjusting the symbol interval between adjacent symbols in the random arrangement result of the orthogonal code elements; (c) combining the execution of random arrangement and symbol interval adjustment between adjacent symbols. The transmitting end and the receiving end pre-share the target sequence encoding, and the conflicts include coverage conflict, congestion conflict, and channel conflict; If a conflict is detected, triggering a conflict resolution decision corresponding to the conflict; if no conflict is detected, ranging the receiving end and the transmitting end based on the target ultrasonic signal.

4. The method according to claim 3, wherein After the step of receiving at least one ultrasonic signal, it further includes: If the target sequence encoding is not identified in each ultrasonic signal, it is determined as a coverage conflict, and the transmitting end is notified to retransmit the target ultrasonic signal containing the target sequence encoding; The step of performing conflict detection on the transmission channel of the target ultrasonic signal under multiple decisions includes: If no coverage conflict occurs and the peak-to-average ratio of the target ultrasonic signal is lower than a preset peak-to-average ratio threshold, it is determined as a congestion conflict, and the transmitting end is notified to retransmit the target ultrasonic signal containing the target sequence encoding; If no congestion conflict occurs and the relative relationship between the arrival time difference of the first target ultrasonic signal and the second target ultrasonic signal and the signal intensity of the first target ultrasonic signal and the second target ultrasonic signal does not conform to the acoustic reflection law, it is determined as a channel conflict, and the transmitting end is notified to reselect the target sequence encoding and generate a new target ultrasonic signal for broadcasting.

5. The method according to claim 3, wherein The orthogonal code elements include a first code element and a second code element. Before the step of ranging the receiving end and the transmitting end based on the target ultrasonic signal, it further includes: Identifying the time-domain forward shift feature of the first code element correlation peak and the time-domain backward shift feature of the second code element correlation peak; Calculate the Doppler frequency offset estimation under the relative moving speed between the transmitter and the receiver according to the time-domain forward shift feature and the time-domain backward shift feature; Perform time delay compensation on the target ultrasonic signal according to the Doppler frequency offset estimation to eliminate the Doppler effect of the target ultrasonic signal.

6. The method according to claim 3, wherein The step of ranging the receiver and the transmitter based on the target ultrasonic signal includes: Obtain a first timestamp and a second timestamp when the transmitter sends the target ultrasonic signal, where the first timestamp is the first time when the transmitter records itself sending the target ultrasonic signal, and the second timestamp is the second time when the receiver records itself receiving the target ultrasonic signal; When returning the target ultrasonic signal to the transmitter, obtain a third timestamp and a fourth timestamp, where the third timestamp is the third time when the receiver records itself sending the target ultrasonic signal, and the fourth timestamp is the fourth time when the transmitter records itself receiving the target ultrasonic signal; Calculate the propagation delay of the target ultrasonic signal based on the first difference between the fourth timestamp and the first timestamp, and the second difference between the third timestamp and the second timestamp; Obtain the distance between the receiver and the transmitter of the ultrasonic signal according to the propagation delay and the propagation speed of the ultrasonic wave.

7. The method according to claim 3, characterized in that The orthogonal code elements include a first code element and a second code element. After the step of receiving at least one ultrasonic signal, it includes: Perform filtering processing on the received ultrasonic signal to obtain a preprocessed ultrasonic signal; Calculate the first channel response curve of the preprocessed ultrasonic signal and the first code element and the second channel response curve of the second code element; Under the condition of eliminating the cross-correlation interference between the first channel response curve and the second channel response curve, based on the time-domain compressed code element interval, search for a correlation peak combination that matches the time-domain distribution of the target sequence coding from the first channel response curve and the second channel response curve; Determine the target ultrasonic signal that matches the time-domain feature of the target sequence coding according to the time-domain position and coding interval consistency of the correlation peak combination.

8. An ultrasonic ranging system, characterized in that, The ultrasonic ranging system includes a transmitter and a receiver. The transmitter is configured to implement the steps of the ultrasonic ranging method described in any one of claims 1 to 2, and / or, the receiver is configured to implement the steps of the ultrasonic ranging method described in any one of claims 3 to 7.

9. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the ultrasonic ranging method described in any one of claims 1 to 2, and / or, the steps of the ultrasonic ranging method described in any one of claims 3 to 7.

10. A computer program product, characterized in that, The computer program product includes a computer program. When the computer program is executed by a processor, it implements the steps of the ultrasonic ranging method described in any one of claims 1 to 2, and / or, the steps of the ultrasonic ranging method described in any one of claims 3 to 7.

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