A Wireless Two-Way Ranging Method and Device Based on Synchronous Sequence Detection

Abstract

The present invention discloses a wireless two-way ranging method and device based on synchronization sequence detection. The method includes: S1. The host device sends a first synchronization sequence at a predetermined transmission frame count time point of the wireless frame; S2. The slave device detects the first synchronization sequence; S3. The slave device adjusts the frame count of its own wireless frame according to the frame count time point of the detected first synchronization sequence, so that the wireless frame time of the slave device is synchronized with the wireless frame transmission time of the host device; S4. The slave device sends a second synchronization sequence at a predetermined frame count time point of its own wireless frame; S5. The host device detects the second synchronization sequence; S6. The host device calculates the distance between the host device and the slave device according to the value of the wireless frame transmission time timer when the second synchronization sequence frame count time point is detected. This method not only has high ranging accuracy, but also avoids the mutual transmission of ranging messages, and does not need to rely on Beidou or GPS time synchronization, making it easy to implement in practical systems.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and particularly to a wireless two-way ranging method and device based on synchronization sequence detection. Background Art

[0002] In engineering applications, it is often necessary to know the straight-line distance between two devices. The method commonly used to measure the distance between two devices using wireless signals is to calculate it through the TOF (Time of Flight). To obtain the TOF, the two devices need to mutually send ranging messages and respond. First, calculate the two-way transmission time, and then calculate the distance between the devices.

[0003] Another way is the method of synchronous timekeeping for all devices. Multiple devices maintain a same high-precision synchronous clock (for example: all devices use GPS timekeeping, and the time is exactly the same). The devices send ranging messages at their respective preset time points without response. The receiving end calculates the one-way transmission time based on the time point when the message is received, and then calculates the distance between the devices.

[0004] Although the first method above can measure the distance between devices more accurately, it is relatively troublesome. First, the two devices need to mutually send ranging messages (ranging request signals) and respond, occupying the wireless transmission bandwidth. In the case of poor communication quality of the wireless transmission link, message parsing errors will lead to inability to perform real-time ranging or large ranging errors. The second method requires synchronous timekeeping between devices to maintain clock synchronization, and it cannot be used in devices without GPS or Beidou timekeeping. And if there is an error in clock synchronization, the ranging result will also be inaccurate. Therefore, a simpler and more reliable ranging method is needed. Summary of the Invention

[0005] The present invention provides a wireless two-way ranging method and device based on synchronization sequence detection to solve the above technical problems.

[0006] The technical solution adopted by the present invention is: to provide a wireless two-way ranging method based on synchronization sequence detection, including:

[0007] S1. The host device sends a first synchronization sequence at a predetermined transmission frame count time point of the wireless frame.

[0008] S2. The slave device detects the first synchronization sequence.

[0009] S3. The slave device adjusts the frame count of its own wireless frame according to the frame count time point of the detected first synchronization sequence, so that the time of the slave device's wireless frame is synchronized with the time when the host device sends the wireless frame.

[0010] S4. The slave device sends a second synchronization sequence at the frame count time point predetermined for the wireless frame of the local device;

[0011] S5. The master device detects the second synchronization sequence;

[0012] S6. The master device calculates the distance between the master device and the slave device according to the value of the wireless frame time timer when the second synchronization sequence frame count time point is detected.

[0013] Further, in the step S3, the method for synchronizing the wireless frame time of the slave device with the wireless frame transmission time of the master device includes:

[0014] S3.1. Obtain the frame count time point T of the wireless frame sent by the master device when sending the first synchronization sequence a ;

[0015] S3.2. Obtain the clock cycle T of the first synchronization sequence b ;

[0016] S3.3. Obtain the clock cycle T of the detection delay of the slave device c ;

[0017] S3.4. After the first synchronization sequence passes through the signal transmission delay T x the frame count time point T of the first synchronization sequence detected by the slave device k = T a + T b + T c + T x ;

[0018] S4.4. Adjust the frame count of the wireless frame of the slave device to T k .

[0019] Further, in the step S6, the method for calculating the distance between the master device and the slave device includes:

[0020] S6.1. Obtain the value T1 of the wireless frame time timer corresponding to the frame count time point when the master device detects the second synchronization sequence;

[0021] S6.2. Obtain the frame count time point T predetermined for the wireless frame of the slave device in S4 d , calculate the difference T d between the frame count time point T k predetermined for the wireless frame of the slave device and the frame count time point T f when the slave device detects the first synchronization sequence;

[0022] S6.3. Obtain the frame count time point T0 of the wireless frame sent by the master device when the master device detects the second synchronization sequence when the distance between the master device and the slave device is zero;

[0023] S6.4. Calculate the time difference Δt1 for bidirectional transmission between the host device and the slave device. Δt1 = T1 - T0 = 2T x ;

[0024] S6.5. According to the radio propagation rate, the host device calculates the distance between the two devices. The calculation formula is expressed as where c is the radio propagation rate of 3 * 10 8 m / s.

[0025] Further, after S6, it further includes:

[0026] S7. The host device adjusts the frame count of the wireless frames received by itself according to the frame count time point of the detected second synchronization sequence, so that the time for the host device to receive wireless frames is synchronized with the time of the wireless frames of the slave device;

[0027] S8. The host device sends a third synchronization sequence at the predetermined frame count time point for receiving wireless frames;

[0028] S9. The slave device detects the third synchronization sequence;

[0029] S10. The slave device calculates the distance between the slave device and the host device according to the value of the wireless frame time timer of the slave device when detecting the frame count time point of the third synchronization sequence.

[0030] Further, the duration of sending and receiving wireless frames of the host device is the same. When sending wireless frames, after the host device is powered on, it continuously accumulates and counts according to the clock signal and times. After counting to the maximum value of a wireless frame, it is cleared and continues to continuously accumulate and count, repeating all the time; while receiving wireless frames will be adjusted according to the second synchronization sequence sent by the slave device.

[0031] Further, in S7, the method of synchronizing the time for the host device to receive wireless frames with the time of the wireless frames of the slave device includes:

[0032] S3.1. Obtain the frame count time point T of the wireless frame when the slave device sends the second synchronization sequence a’ ;

[0033] S3.2. Obtain the clock period T of the second synchronization sequence b’ ;

[0034] S3.3. Obtain the clock period T of the delay detected by the slave device c’ ;

[0035] S3.4. After the second synchronization sequence passes through the signal transmission delay T x’ the host device detects the frame count time point T of the second synchronization sequence k’= T a’ + T b’ + T c’ + T x’ ;

[0036] S4.4. Adjust the frame count of the wireless frame of the host device to T k’ .

[0037] Furthermore, in the above S10, the method for calculating the distance between the slave device and the host device includes:

[0038] S10.1. Obtain the value T3 of the wireless frame time timer corresponding to the time point of the third synchronization sequence frame count detected by the slave device;

[0039] S10.2. Obtain the predetermined frame count time point T of the wireless frame received by the host device in S7 d’ , calculate the difference T d’ between the predetermined frame count time point T of the wireless frame received by the host device and the frame count time point T k’ of the second synchronization sequence detected by the host device f’ ;

[0040] S10.3. Obtain the value T2 of the wireless frame time counter when the slave device detects the third synchronization sequence when the host device and the slave device are at zero distance;

[0041] S10.4. Calculate the time difference Δt2 of the bidirectional transmission between the host device and the slave device, Δt2 = T3 - T2 = 2T x’ ;

[0042] S10.5. According to the radio propagation rate, the slave device calculates the distance between the two devices, and the calculation formula is expressed as where c is the radio propagation rate 3 * 10 8 m / s.

[0043] Furthermore, the first synchronization sequence, the second synchronization sequence, and the third synchronization sequence are all ZC sequences.

[0044] The present invention also provides a wireless bidirectional ranging device based on synchronization sequence detection, including a host device and a slave device. The host device includes a wireless frame sending module, a wireless frame receiving module, and a first calculation module; the slave device includes a slave device sending module, a slave device receiving module, and a second adjustment module;

[0045] The wireless frame sending module is used to send the first synchronization sequence at a predetermined sending frame count time point;

[0046] The slave device receiving module is used to detect the first synchronization sequence;

[0047] The second adjustment module is used to adjust the frame count of the local wireless frame according to the frame count time point of the first synchronization sequence detected by the slave device receiving module, so that the wireless frame time of the slave device is synchronized with the wireless frame time of the host device sending module;

[0048] The slave device sending module is used to send a second synchronization sequence at the predetermined frame count time point of the local wireless frame;

[0049] The receiving wireless frame module is used to detect the second synchronization sequence;

[0050] The first calculation module is used to calculate the distance between the host device and the slave device according to the value of the wireless frame time timer of the sending wireless frame module when the receiving wireless frame module detects the frame count time point of the second synchronization sequence frame.

[0051] Further, the host device further includes a first adjustment module, and the slave device further includes a second calculation module;

[0052] The first adjustment module is used to adjust the frame count of the local receiving wireless frame module according to the frame count time point of the second synchronization sequence detected by the receiving wireless frame module, so that the wireless frame time of the host device receiving is synchronized with the wireless frame time of the slave device;

[0053] The sending wireless frame module is used to send a third synchronization sequence at the predetermined sending frame count time point;

[0054] The slave device receiving module is used to detect the third synchronization sequence;

[0055] The second calculation module is used to calculate the distance between the slave device and the host device according to the value of the wireless frame time timer of the slave device receiving module when the slave device receiving module detects the frame count time point of the third synchronization sequence.

[0056] The beneficial effects of the present invention are as follows: The method of the present invention not only has high ranging accuracy, but also avoids the mutual transmission of ranging messages, and does not need to rely on Beidou or GPS time synchronization, which is easy to implement in practical systems. Therefore, it has high application value and popularization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic flowchart of a wireless bidirectional ranging method based on synchronization sequence detection disclosed in an embodiment of the present invention.

[0058] Figure 2 It is a schematic diagram of a wireless frame disclosed in an embodiment of the present invention.

[0059] Figure 3 It is a schematic diagram of the distances obtained by wireless ranging and Beidou satellite ranging of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0060] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. However, the embodiments of the present invention are not limited thereto.

[0061] Embodiment 1:

[0062] Refer to Figures 1-3 , the present invention discloses a wireless two-way ranging method based on synchronization sequence detection, including the following steps:

[0063] (S1) The host device sends a first synchronization sequence Syn1 at a predetermined time point for sending a wireless frame (a total of three different synchronization sequences need to be sent in the whole process). Syn1 usually adopts a sequence with better correlation characteristics, such as a ZC sequence, etc.

[0064] (S2) The slave device retrieves the first synchronization sequence Syn1 described in step (S1) by means of correlation detection. If the correlation peak is greater than the threshold value, it means that the first synchronization sequence Syn1 has been detected.

[0065] (S3) According to the time point when the first synchronization sequence Syn1 is detected in step (S2), the slave device adjusts the frame count of its own wireless frame so that its wireless frame time is synchronized with the wireless frame sending time of the host. When adjusting the wireless frame time, the sending duration of the synchronization sequence and the detection duration of the synchronization sequence need to be considered.

[0066] For example, the host sends the first synchronization sequence Syn1 at the 1000th frame count time point (denoted as T a ) of sending a wireless frame of this device. The length of Syn1 is 128 clock cycles (denoted as T b ), and the detection delay of the slave is 32 clock cycles (denoted as T c ). Then the slave device adjusts the frame count of its own wireless frame at the time point when the first synchronization sequence Syn1 is detected, and adjusts it to 1160 (1000 + 128 + 32). If the master and slave devices are at zero distance (i.e., the signal transmission delay is 0), at this time, the sending wireless frame count of the host is theoretically also 1160, so that the wireless frame count of the slave is synchronized with the wireless frame sending time of the host. However, if the distance between the master and slave devices is not zero (i.e., there is a transmission delay T x ), then there will be a time difference between the sending frame count of the host and the wireless frame count of the slave, and this time difference is a part of the time difference obtained when calculating the distance; for example, when there is a certain distance between the master and slave devices, the transmission delay T x is 800 frame count time points. At this time, in the subsequent (S6), T1 = 1160 + 800 + the difference T between the predetermined frame count time point T d of the wireless frame of the slave device and the frame count time point T k when the slave device detects the first synchronization sequencef .

[0067] (S4) After the slave device adjusts its local wireless frame time according to step (S3) and synchronizes with the transmission time of the wireless frame of the master device, it can receive other data information sent by the master device. The slave device sends a second synchronization sequence Syn2 to the master device at a predetermined time point of its local wireless frame. Syn2 also uses a sequence with good correlation characteristics, such as the ZC sequence, etc.

[0068] For example, the frame count time point T of the slave device's wireless frame d and the frame count time point T when the slave device detects the first synchronization sequence k The difference T f = 40 frame count time points, then in the subsequent step (S6), T1 = 1160 + 800 + 40 = 2000. The slave device can also send the second synchronization sequence Syn2 to the master device immediately when it detects the first synchronization sequence. At this time, T f = 0.

[0069] (S5) The master device uses the correlation detection method to retrieve the second synchronization sequence Syn2 described in step (S4). If the correlation peak is greater than the threshold value, it means that the second synchronization sequence Syn2 has been detected.

[0070] (S6) The master device records the value T1 of the wireless frame transmission time timer at the time point when the second synchronization sequence Syn2 is detected in step (S5). T1 = T b + T c + T f + T x + T b + T c + T x , and performs a difference operation with the value T0 of the wireless frame transmission time timer when the two devices are at zero distance. T0 = T b + T c + T f + T b + T c , to obtain the time difference Δt1 of the two-way transmission between the master and slave devices. Δt1 = T1 - T0 = 2T x ; and according to the radio propagation rate, the master device calculates the distance between the two devices. The calculation formula is expressed as where c is the radio propagation rate of 3*10 8 m / s.

[0071] The above step (S6) is the distance between the master and slave devices calculated from the master device.

[0072] (S7) Based on the time point when the host device detects the second synchronization sequence Syn2 in step (S5), the host device adjusts the time for receiving wireless frames of its own, so that the time for receiving wireless frames is synchronized with the time of the slave device's wireless frames. When adjusting the wireless frame time, the transmission duration of the synchronization sequence and the detection duration of the synchronization sequence need to be considered.

[0073] It should be noted that the host has two frame counts, one is the transmission frame count and the other is the reception frame count. The duration of the host device's transmitting and receiving wireless frames is the same. The transmitting of wireless frames is that after the host device is powered on, it continuously accumulates and counts according to the clock signal and times. After counting to the maximum value of a wireless frame, it is cleared and continues to continuously accumulate and count, repeating all the time. While the reception frame count will be adjusted according to the time point when the second synchronization sequence Syn2 sent by the slave is detected, and it may be non - continuous. The adjustment mechanism is similar to (S3). For example, the slave sends the second synchronization sequence Syn2 at the 2000th frame count time point (denoted as T a’ ) of its own transmitting wireless frame. The length of Syn2 is 128 clock cycles (denoted as T b’ ), and the host detection delay is 32 clock cycles (denoted as T c’ ). Then the host adjusts the frame count of receiving wireless frames at the time point when it detects the second synchronization sequence Syn2 to 2160 (2000 + 128 + 32). Without considering the signal transmission delay (that is, the distance between the master and slave devices is 0), at this time, the frame count of the slave is theoretically also 2160, so that the time for the host to receive wireless frames is synchronized with the time of the slave. However, if there is a transmission delay T x’ (that is, the distance between the master and slave devices is not 0), then there will be a time difference between the host's reception frame count and the slave's wireless frame count.

[0074] (S8) The host device sends the third synchronization sequence Syn3 at the predetermined time point for receiving wireless frames. Syn3 usually also uses sequences with better correlation characteristics, such as ZC sequences, etc.

[0075] Similar to step (S4), the difference T d’ between the predetermined frame count time point T k’ of the host device's wireless frames and the frame count time point T f’ when the host device detects the second synchronization sequence can be 0 or not 0.

[0076] (S9) The slave device uses the correlation detection method to retrieve the third synchronization sequence Syn3 described in step (S8). If the correlation peak is greater than the threshold value, it means that the third synchronization sequence Syn3 has been detected.

[0077] (S10) The slave device records the value of the wireless frame time timer at this time, T3, according to the detected time point of the third synchronization sequence Syn3 in step (S9), and performs a difference operation with the value of the wireless frame time timer T2 sent when the two devices are at zero distance, to obtain the time difference Δt2 of the two-way transmission between the master and slave devices, Δt2 = T3 - T2 = 2T x’ , and according to the radio propagation rate, the slave device calculates the distance between the two devices, and the calculation formula is expressed as where c is the radio propagation rate of 3*10 8 m / s.

[0078] The above step (S10) is to calculate the distance between the master and slave devices according to the slave device. Combining step (S6), it can be known that the present invention enables both devices to conveniently and accurately obtain the distance information between them.

[0079] Figure 3 The application of this embodiment in actual engineering is given. The method is used for one-to-many wireless ranging, and at the same time, the Beidou ranging results of the two devices are given for comparison (the black frame part). It can be seen that the wireless ranging accuracy of this embodiment is very high, and the error is less than 5 meters at about three thousand meters.

[0080] Through the above steps, the method of the present invention not only has high ranging accuracy, but also avoids the mutual transmission of ranging messages, and does not require Beidou or GPS time synchronization, which is easy to implement in an actual system. Therefore, it has high application value and promotion value.

[0081] Embodiment 2:

[0082] This embodiment provides a wireless two-way ranging device based on synchronization sequence detection. The device realizes ranging between the host device and the slave device through the method of Embodiment 1. Specifically, the device includes a host device and a slave device. The host device includes a wireless frame sending module, a wireless frame receiving module, and a first calculation module; the slave device includes a slave device sending module, a slave device receiving module, and a second adjustment module;

[0083] The wireless frame sending module is used to send the first synchronization sequence at a predetermined sending frame count time point;

[0084] The slave device receiving module is used to detect the first synchronization sequence;

[0085] The second adjustment module is used to adjust the frame count of the local wireless frame according to the frame count time point of the first synchronization sequence detected by the slave device receiving module, so that the wireless frame time of the slave device is synchronized with the time of the wireless frame sending module of the host device;

[0086] The slave device sending module is used to send a second synchronization sequence at the frame count time point of the local wireless frame;

[0087] The receiving wireless frame module is used to detect the second synchronization sequence;

[0088] The first calculation module is used to calculate the distance between the host device and the slave device according to the value of the wireless frame time timer of the sending wireless frame module when the receiving wireless frame module detects the frame count time point of the second synchronization sequence frame.

[0089] Furthermore, the host device further includes a first adjustment module, and the slave device further includes a second calculation module;

[0090] The first adjustment module is used to adjust the frame count of the local receiving wireless frame module according to the frame count time point of the second synchronization sequence detected by the receiving wireless frame module, so that the host device receiving wireless frame time is synchronized with the slave device wireless frame time;

[0091] The sending wireless frame module is used to send a third synchronization sequence at the predetermined sending frame count time point;

[0092] The slave device receiving module is used to detect the third synchronization sequence;

[0093] The second calculation module is used to calculate the distance between the slave device and the host device according to the value of the wireless frame time timer of the slave device receiving module when the slave device receiving module detects the frame count time point of the third synchronization sequence.

[0094] Through this device, the host device can calculate the distance between the host device and the slave device, and the slave device can also calculate the distance between the host device and the slave device.

[0095] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wireless two-way ranging method based on synchronous sequence detection, characterized in that, Including: S1. The host device sends a first synchronization sequence at a predetermined transmission frame count time point of the wireless frame. S2. The slave device detects the first synchronization sequence. S3. The slave device adjusts the frame count of its own wireless frame according to the frame count time point of the detected first synchronization sequence, so that the wireless frame time of the slave device is synchronized with the wireless frame transmission time of the host device. S4. The slave device sends a second synchronization sequence at a predetermined frame count time point of its own wireless frame. S5. The host device detects the second synchronization sequence. S6. The host device calculates the distance between the host device and the slave device according to the value of the wireless frame transmission time timer when detecting the frame count time point of the second synchronization sequence. In S6, the method for calculating the distance between the host device and the slave device includes: S6.

1. Obtain the value T1 of the wireless frame transmission time timer corresponding to the frame count time point when the host device detects the second synchronization sequence. S6.

2. Obtain the frame count time point T reserved for the slave device's wireless frame in S4 d , and calculate the frame count time point T reserved for the slave device's wireless frame d and the frame count time point T when the slave device detects the first synchronization sequence k The difference T between them f ; S6.

3. Obtain the frame count time point T0 when the host device sends a wireless frame when detecting the second synchronization sequence when the distance between the host device and the slave device is zero. S6.

4. Calculate the time difference ∆t1 for the bidirectional transmission between the host device and the slave device. ∆t1 = T1 - T0 = 2T x ; S6.

5. According to the radio propagation rate, the host device calculates the distance between the two devices, and the calculation formula is expressed as , where c is the radio propagation rate of 3×10 8 m / s.

2. The wireless two-way ranging method based on synchronization sequence detection according to claim 1, characterized in that, In S3, the method for synchronizing the wireless frame time of the slave device with the wireless frame transmission time of the host device includes: S3.

1. Obtain the frame count time point T of the wireless frame sent when the host device sends the first synchronization sequence a ; S3.

2. Obtain the clock cycle T of the first synchronization sequence b ; S3.

3. Obtain the clock cycle T of the slave detection delay c ; S3.

4. The first synchronization sequence undergoes a signal transmission delay T x After that, the slave device detects the frame count time point T of the first synchronization sequence k = T a + T b + T c + T x ; S3.

5. Adjust the frame count of the wireless frame of the slave device to T k .

3. The wireless two-way ranging method based on synchronization sequence detection according to claim 1 or 2, characterized in that, After S6, it further includes: S7. The host device adjusts the frame count of its received wireless frame according to the frame count time point of the detected second synchronization sequence, so that the wireless frame reception time of the host device is synchronized with the wireless frame time of the slave device. S8. The host device sends a third synchronization sequence at a predetermined frame count time point of the received wireless frame. S9. The slave device detects the third synchronization sequence. S10. The slave device calculates the distance between the slave device and the host device according to the value of the wireless frame time timer of the slave device when detecting the frame count time point of the third synchronization sequence.

4. The wireless two-way ranging method based on synchronization sequence detection according to claim 3, wherein, The transmission duration and reception duration of the wireless frame of the host device are the same. When transmitting the wireless frame, after the host device is powered on, it continuously accumulates and counts according to the clock signal and times. After counting to the maximum value of a wireless frame, it is cleared and continues to continuously accumulate and count, repeating all the time; while the reception of the wireless frame will be adjusted according to the received second synchronization sequence sent by the slave device.

5. The wireless two-way ranging method based on synchronization sequence detection according to claim 4, wherein In S7, the method for synchronizing the wireless frame reception time of the host device with the wireless frame time of the slave device includes: S3.

1. Obtain the frame count time point T of the wireless frame sent when the slave device sends the second synchronization sequence a’ ; S3.

2. Obtain the clock cycle T of the second synchronization sequence b’ ; S3.

3. Obtain the clock cycle T of the slave detection delay c’ ; S3.

4. The second synchronization sequence undergoes a signal transmission delay T x’ After that, the host device detects the frame count time point T of the second synchronization sequence k’ = T a’ + T b’ + T c’ + T x’ ; S3.

5. Adjust the frame count of the wireless frame of the host device to T k’ .

6. The wireless two-way ranging method based on synchronization sequence detection according to claim 4, wherein In S10, the method for calculating the distance between the slave device and the host device includes: S10.

1. Obtain the value T3 of the wireless frame time timer corresponding to the frame count time point when the slave device detects the third synchronization sequence. S10.

2. Obtain the frame count time point T at which the host device in S7 is scheduled to receive a wireless frame d’ , and calculate the frame count time point T at which the host device is scheduled to receive a wireless frame d’ and the frame count time point T at which the host device detects the second synchronization sequence k’ The difference T between them f’ ; S10.

3. Obtain the value T2 of the wireless frame time counter when the slave device detects the third synchronization sequence when the distance between the host device and the slave device is zero. S10.

4. Calculate the time difference ∆t2 for the bidirectional transmission between the host device and the slave device. ∆t2 = T3 - T2 = 2T x’ ; S10.

5. Calculate the distance between the two devices by the slave device according to the radio propagation rate, and the calculation formula is expressed as , where c is the radio propagation rate of 3×10 8 m / s.

7. The wireless two-way ranging method based on synchronization sequence detection according to claim 3, characterized in that, The first synchronization sequence, the second synchronization sequence, and the third synchronization sequence are all ZC sequences.

8. A wireless two-way ranging device based on synchronous sequence detection, characterized in that Including a host device and a slave device. The host device includes a wireless frame transmission module, a wireless frame reception module, and a first calculation module; the slave device includes a slave device transmission module, a slave device reception module, and a second adjustment module. The wireless frame transmission module is used to send a first synchronization sequence at a predetermined transmission frame count time point. The slave device reception module is used to detect the first synchronization sequence. The second adjustment module is used to adjust the frame count of the local wireless frame according to the frame count time point of the first synchronization sequence detected by the slave device receiving module, so that the wireless frame time of the slave device is synchronized with the wireless frame time of the host device sending module; The slave device sending module is used to send a second synchronization sequence at the predetermined frame count time point of the local wireless frame; The wireless frame receiving module is used to detect the second synchronization sequence; The first calculation module is used to calculate the distance between the host device and the slave device according to the value of the wireless frame time timer of the wireless frame sending module when the second synchronization sequence frame count time point is detected by the wireless frame receiving module; The wireless frame receiving module is used to obtain the value T1 of the transmission wireless frame time timer corresponding to the second synchronization sequence frame count time point detected by the host device, and obtain the frame count time point T of the wireless frame predetermined by the slave device in S4. d , and obtain the frame count time point T0 of the wireless frame transmitted when the host device detects the second synchronization sequence when the distance between the host device and the slave device is zero; The first calculation module is used to calculate the frame count time point T reserved for the wireless frame of the slave device d and the frame count time point T when the slave device detects the first synchronization sequence k The difference T between them f ; calculate the time difference ∆t1 of the two-way transmission between the host device and the slave device, and calculate the distance between the two devices.

9. The wireless two-way ranging device based on synchronous sequence detection according to claim 8, characterized in that, The host device further includes a first adjustment module, and the slave device further includes a second calculation module; The first adjustment module is used to adjust the frame count of the local wireless frame receiving module according to the frame count time point of the second synchronization sequence detected by the wireless frame receiving module, so that the wireless frame receiving time of the host device is synchronized with the wireless frame time of the slave device; The wireless frame sending module is used to send a third synchronization sequence at the predetermined sending frame count time point; The slave device receiving module is used to detect the third synchronization sequence; The second calculation module is used to calculate the distance between the slave device and the host device according to the value of the wireless frame time timer of the slave device receiving module when the third synchronization sequence frame count time point is detected by the slave device receiving module.

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