Capacitive coupling communication method, device, system and medium
By adopting capacitively coupled communication method in oil drilling, and generating AC square wave signals at both ends of capacitors, the complexity of inductively coupled communication technology and electromagnetic interference are solved, and high-quality signal transmission is achieved.
Patent Information
- Application Number
- CN202411327422.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2024-12-27
AI Technical Summary
Inductive coupled communication technology in existing oil drilling has problems such as high design complexity, high cost and susceptibility to electromagnetic interference, which affects the quality of signal transmission.
Capacitive coupling communication method is adopted to generate AC square wave signals at both ends of the capacitor, and the signal is sent to the power line by capacitive coupling, so that the signal transmission is achieved, circuit matching and tuning problems are avoided, and electromagnetic interference is reduced.
Simplify the structure, reduce costs, improve signal integrity, transmission quality and stability, and avoid the influence of electromagnetic interference.
Smart Images
Figure CN119210511A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of downhole communication of oil drilling instruments, and in particular to a capacitive coupling communication method, device, system and medium. Background Art
[0002] In the related technology, during the oil drilling process, a single bus communication module is usually used to superimpose the communication waveform on the power supply voltage to form a single bus communication. The commonly used signal transmission and reception method is to use inductive coupling transmission. Although inductive coupling transmission is suitable for high-frequency signal transmission, the inductor requires precise circuit matching and tuning to ensure accurate data transmission. Therefore, the design complexity and production cost are high, and the inductor is easy to interfere with the surrounding electromagnetic equipment, affecting the quality of signal transmission. Summary of the invention
[0003] Based on this, it is necessary to provide a capacitive coupling communication method, device, system and medium that can be applicable to power line carrier communication in order to solve the above technical problems.
[0004] A capacitive coupling communication method is applied to a capacitive coupling communication system, the method comprising:
[0005] Encode the data to be sent to obtain the corresponding encoding value;
[0006] Generate a control signal, and generate an AC square wave signal corresponding to the encoding value at both ends of the square wave generating capacitor according to the control signal; the control signal is used to switch the polarity of both ends of the square wave generating capacitor; the square wave generating capacitor is a component in the signal transmitting module of the capacitive coupling communication system;
[0007] The AC square wave signal is sent to the power line by means of coupling capacitors and transmitted through the power line.
[0008] In the above solution, generating an AC square wave signal corresponding to the coding value at both ends of a square wave generating capacitor according to the control signal includes:
[0009] According to the control signal, the working loop of the square wave generating capacitor is selected in the first loop and the second loop; wherein, in the first loop, the first end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U1, and the second end of the square wave generating capacitor is grounded through the MOS tube U3; in the second loop, the first end of the square wave generating capacitor is grounded through the MOS tube U2, and the second end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U4.
[0010] In the above scheme, generating an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal includes:
[0011] Generate a first control signal to put the MOS transistors in the first loop and the second loop into a cut-off state;
[0012] A second control signal is generated to make the MOS transistor of one of the first loop and the second loop in a conducting state, and the MOS transistor of the other loop in a cutting-off state.
[0013] In the above scheme, the control signal includes a gate control signal of the MOS tube U1, a gate control signal of the MOS tube U2, a gate control signal of the MOS tube U3 and a gate control signal of the MOS tube U4; wherein the turn-off delays of the MOS tube U1, the MOS tube U2, the MOS tube U3 and the MOS tube U4 are all less than the charging and discharging time of the square wave generating capacitor; the charging and discharging time of the square wave generating capacitor is determined based on the duty ratio of the gate control signal of the MOS tube U1 and the gate control signal of the MOS tube U4, the duty ratio of the gate control signal of the MOS tube U2 and the gate control signal of the MOS tube U3 and the coding frequency.
[0014] In the above scheme, generating an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal includes:
[0015] The data 1 in the coding value is represented by at least two continuous AC square wave signals, and the data 0 in the coding value is represented by a constant level of a set duration; wherein the AC square wave signal has a preset fixed frequency.
[0016] In the above scheme, the coding value is at least one group, and each group of the coding values includes a synchronization code, a data code located after the synchronization code, and a check code located after the data code.
[0017] In the above scheme, the method further includes:
[0018] Receiving an AC square wave signal on the power line, and performing filtering and shaping processing on the AC square wave signal to obtain a positive half-axis square wave signal;
[0019] The positive half-axis square wave signal is compared with a set reference voltage, and based on the comparison result, a square wave signal that meets the set requirements is output.
[0020] A capacitive coupling communication device, applied to a capacitive coupling communication system, comprising:
[0021] The encoding module is used to encode the data to be sent to obtain the corresponding encoding value;
[0022] A square wave generating module, used to generate a control signal, and generate an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal; the control signal is used to switch the polarity of both ends of the square wave generating capacitor; the square wave generating capacitor is a component in the signal transmitting module of the capacitive coupling communication system;
[0023] The signal sending module is used to send the AC square wave signal to the power line through a coupling capacitor, and transmit it through the power line.
[0024] A capacitive coupling communication system comprises a memory and a processor. The memory stores a computer program. When the processor executes the computer program, the capacitive coupling communication method is implemented.
[0025] A computer-readable storage medium stores a computer program, which implements the capacitive coupling communication method when executed by a processor.
[0026] The above-mentioned capacitive coupling communication method, device, system and medium, the capacitive coupling communication system encodes the transmitted data to obtain the corresponding coding value, generates a control signal, and generates an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal, which can generate a clear square wave signal and reduce signal distortion. Then, the AC square wave signal is sent to the power line by coupling capacitor, and transmitted through the power line, so that the signal transmission function can be realized while powering, and the power supply voltage of the power line will not affect the production of the square wave AC signal, which can effectively improve the signal integrity, transmission quality and stability. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a schematic diagram of capacitive coupled single bus carrier communication;
[0028] Figure 2 is a schematic diagram of a flow chart of a capacitive coupling communication method in one embodiment;
[0029] Figure 3 A circuit diagram of a signal transmission module of a capacitive coupling communication system in one embodiment;
[0030] Figure 4 A schematic diagram of a flow chart of controlling the polarity of both ends of a square wave generating capacitor in one embodiment;
[0031] Figure 5 A pulse timing diagram of a MOS tube in one embodiment;
[0032] Figure 6 is an AC square wave signal corresponding to data bit 1 and data bit 0 in one embodiment;
[0033] Figure 7 A schematic diagram of a data structure of a set of coded values in one embodiment;
[0034] Figure 8 A schematic diagram of a flow chart of processing a received signal in one embodiment;
[0035] Fig. 9 FIG. 4 is a structural block diagram of a capacitive coupling device in one embodiment. DETAILED DESCRIPTION
[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0037] The implementation details of the technical solution of the embodiment of the present invention are described in detail below.
[0038] like Figure 1 As shown, Figure 1 The capacitive coupling communication system is based on Figure 1 The signal is sent and received. When using capacitive coupling signals, there is no need to consider the circuit matching and tuning of high-frequency signals, so the structure is simple and easy to miniaturize and integrate. When the capacitor is working, the electromagnetic waves radiated outward are small, and it is not easy to interfere with the surrounding electromagnetic equipment. The environmental electromagnetic waves will only affect the capacitance of the capacitor, and will not directly affect the waveform of the capacitive coupling signal, so it is not easily interfered by the surrounding electromagnetic equipment.
[0039] In one embodiment, Figure 2 As shown, a capacitive coupling communication method is provided, and the capacitive coupling communication method is applied to a capacitive coupling communication system. The method may include the following steps:
[0040] Step S101, encoding the data to be sent to obtain a corresponding encoding value.
[0041] In the oil drilling work scenario, the data to be sent may include sensor data, equipment status information, control instructions, etc. These data to be sent are all analog data. Before sending the data to be sent, it is necessary to encode the data to be sent to obtain the encoding value (such as a binary number) corresponding to the data to be sent, thereby converting the data to be sent from an analog signal to a digital signal, which can improve the transmission efficiency and anti-interference ability of the data to be sent.
[0042] Taking the temperature as an example, the temperature sensor is first used to obtain an analog signal, and the analog signal is converted into a digital signal through an analog-to-digital converter. That is, the voltage signal output by the temperature sensor is converted into a corresponding digital value by the analog-to-digital converter, and then the digital signal is further encoded into a binary number to obtain the encoding value corresponding to the data to be sent.
[0043] Step S102 , generating a control signal, and generating an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal.
[0044] Here, the coding value is converted into a corresponding AC square wave signal. The AC square wave signal has clear rising and falling edges, which helps the receiving end to accurately identify the changes in the signal, thereby improving the transmission quality of the signal. Moreover, compared with the DC signal, the AC signal is more resistant to external interference, making it less susceptible to noise.
[0045] This conversion process occurs in the signal transmission module of the capacitive coupling communication system, such as Figure 3 As shown, Figure 3 The circuit diagram of the signal transmission module of the capacitive coupling communication system is shown. The square wave generating capacitor (ie Figure 3 The two ends of C3 in the figure will generate an AC square wave signal, where the principle of generating an AC square wave signal at the two ends of the square wave generating capacitor is:
[0046] When a positive voltage is applied to both ends of the square wave generating capacitor, that is, the upper end of the square wave generating capacitor is positive and the lower end is negative, a positive square wave waveform will be formed at both ends of the square wave generating capacitor; when a low voltage is applied to both ends of the square wave generating capacitor, that is, the upper end of the square wave generating capacitor is negative and the lower end is positive, a negative square wave waveform will be formed at both ends of the square wave generating capacitor.
[0047] Based on this, by controlling the polarity of the two ends of the square wave generating capacitor, the AC square wave signal generated at both ends of the square wave generating capacitor can be controlled, so that the generation of the AC square wave signal will not be affected by the power supply voltage of the power line, and the stability and reliability of the signal can be improved.
[0048] In this embodiment, the polarity of the two ends of the square wave generating capacitor is controlled by a control signal. The corresponding control signal is generated according to the coding value. The polarity of the two ends of the square wave generating capacitor will switch following the control signal, thereby generating an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor.
[0049] In practical applications, in order to facilitate the distinction between data 1 and data 0 in the coded value, data 1 and data 0 in the coded value can be represented by different waveforms. For example, data 1 can be represented by a 200KHz AC square wave signal, and data 0 can be represented by a 300KHz AC square wave signal, which can improve the signal's anti-interference ability and thus improve the signal transmission quality.
[0050] The following uses the 200KHz AC square wave signal as an example to illustrate the generation process of the AC square wave signal:
[0051] A 200KHz AC square wave signal means that each cycle is 5 microseconds. In one cycle, the high level duration is half the cycle, that is, 2.5 microseconds, and the low level duration is also 2.5 microseconds.
[0052] If it is necessary to output an AC square wave signal corresponding to a data bit 1 in the coding value, first generate control signal 1, which makes the upper end of the square wave generating capacitor positive and the lower end negative, and maintains this state for 2.5 microseconds, thereby generating the first half of the AC square wave signal corresponding to data bit 1 at both ends of the square wave generating capacitor; then generate control signal 2, which makes the upper end of the square wave generating capacitor negative and the lower end positive, and maintains this state for 2.5 microseconds, thereby generating the second half of the AC square wave signal corresponding to data bit 1 at both ends of the square wave generating capacitor. It can be seen that by continuously acting on control signal 1 for 2.5 microseconds and control signal 2 for 2.5 microseconds, a 200KHz AC square wave signal for representing data bit 1 can be generated at both ends of the square wave generating capacitor.
[0053] In one embodiment, according to the control signal, the working loop of the square wave generating capacitor is selected in the first loop and the second loop.
[0054] Here, the control signal determines the polarity of the two ends of the square wave generating capacitor by selecting the working loop of the square wave generating capacitor. It can be understood that if the upper end of the square wave generating capacitor is positive and the lower end is negative, it means that the upper end of the square wave generating capacitor needs to be connected to the power supply and the lower end is grounded; if the upper end of the square wave generating capacitor is negative and the lower end is positive, it means that the upper end of the square wave generating capacitor is grounded and the lower end needs to be connected to the power supply.
[0055] Based on this, two circuits are provided for the square wave generating capacitor. In the first circuit, the first end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U1, and the second end of the square wave generating capacitor is grounded through the MOS tube U3. If the square wave generating capacitor works in the first circuit, the first end of the square wave generating capacitor is the positive electrode, and the second end is the negative electrode; in the second circuit, the first end of the square wave generating capacitor is grounded through the MOS tube U2, and the second end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U4. If the square wave generating capacitor works in the second circuit, the first end of the square wave generating capacitor is the negative electrode, and the second end is the positive electrode.
[0056] The generated control signal is input into the gates of MOS transistors U1, U2, U3 and U4, so that MOS transistors U1, U2, U3 and U4 are in an on state or an off state, thereby making the square wave generating capacitor work in the first loop or the second loop.
[0057] Among them, the MOS tube U1 and the MOS tube U4 are P-type MOS tubes, and the MOS tube U2 and the MOS tube U3 are N-type MOS tubes. When the control signals of the MOS tube U1 and the MOS tube U2 are high level and the control signals of the MOS tube U3 and the MOS tube U4 are low level, the MOS tube U1 and the MOS tube U3 are not turned on, and the MOS tube U2 and the MOS tube U4 are turned on, so that the square wave generating capacitor works in the second loop. At this time, the first end of the square wave generating capacitor is grounded, and the second end is connected to the power supply VCC; when the control signals of the MOS tube U1 and the MOS tube U2 are low level and the control signals of the MOS tube U3 and the MOS tube U4 are high level, the MOS tube U1 and the MOS tube U3 are turned on, and the MOS tube U2 and the MOS tube U4 are not turned on, so that the square wave generating capacitor works in the first loop. At this time, the first end of the square wave generating capacitor is connected to the power supply VCC, and the second end is grounded.
[0058] In practical applications, by continuously switching the control signals of each MOS tube, the square wave generating capacitor works alternately in the first loop and the second loop, so that an AC square wave signal can be generated at both ends of the square wave generating capacitor.
[0059] In one embodiment, Figure 4 As shown, Figure 4 A schematic diagram of a process for controlling the polarity of both ends of a square wave generating capacitor is shown.
[0060] Step S201, generating a first control signal to turn off the MOS transistors in the first loop and the second loop.
[0061] Before the circuit in which the square wave generating capacitor works is selected, a first control signal needs to be generated, that is, the control signal input to the MOS transistor U1 and the MOS transistor U4 is a high level, and the control signal input to the MOS transistor U2 and the MOS transistor U3 is a low level. Under the first control signal, the MOS transistors in the first circuit and the second circuit are all in the cut-off state, that is, the MOS transistors U1, MOS transistor U2, MOS transistor U3 and MOS transistor U4 are all disconnected from the square wave generating capacitor.
[0062] Step S202, generating a second control signal to turn on the MOS transistor in one of the first loop and the second loop, and turn off the MOS transistor in the other loop.
[0063] When all MOS transistors are in the off state, a second control signal is generated. The loop to be turned on is selected in the first loop and the second loop through the second control signal, so that the MOS transistors in one of the first loop and the second loop are in the on state, and the MOS transistors in the other loop are in the off state. For example, the second control signal is to input a high level to the gates of the MOS transistors U1 and U2, and input a low level to the gates of the MOS transistors U3 and U4, then the MOS transistors U2 and U4 in the second loop are in the on state, and the MOS transistors U1 and U3 in the first loop are in the off state, so that the square wave generating capacitor works in the second loop.
[0064] In the above embodiment, it is necessary to select the circuit in which the square wave generating capacitor works when all MOS tubes are kept in the cut-off state, and optimize the control timing of the four MOS tubes, which is conducive to generating an accurate and complete AC square wave signal, and can also avoid the situation that the next MOS tube is turned on when the previous MOS tube is not completely turned off when switching the circuit in which the square wave generating capacitor works, and can ensure that multiple MOS tubes will not be turned on, thereby avoiding transient conflicts that cause instability to the circuit.
[0065] In one embodiment, the control signal is to control the conduction state of the MOS tube U1, the MOS tube U2, the MOS tube U3 and the MOS tube U4, thereby selecting the loop in which the square wave generating capacitor works. Therefore, the control signal here includes the gate control signal of the MOS tube U1, the gate control signal of the MOS tube U2, the gate control signal of the MOS tube U3 and the gate control signal of the MOS tube U4.
[0066] In practical applications, in order to ensure the generation of square wave AC signals, the charging and discharging time of the square wave generating capacitor needs to meet certain conditions. Figure 5 As shown, Figure 5Assume that the frequency of the coding signal is f, the amplitude of the AC square wave signal is a, and the charging and discharging time of the square wave generating capacitor (i.e., the amplitude from 0 to a, or the amplitude from a to 0) is Δ / 2. Figure 5 It can be determined that the signal ratio of MOS tube U1 and MOS tube U4 is x, and the signal ratio of MOS tube U2 and MOS tube U3 is 1-x, then:
[0067]
[0068] And the turn-off delays of MOS transistors U1, MOS transistor U2, MOS transistor U3 and MOS transistor U4 are all less than Δ. The turn-off delay refers to the time delay required for the MOS transistor to change from the on state to the off state after the control signal changes state (for example, from a high level to a low level), and this time period is the time interval from the moment the control signal changes until the MOS transistor completely stops conducting. If the turn-off delay is less than Δ, it can ensure that the MOS transistor can be switched in time at the frequency f, thereby ensuring that the AC square wave signal at both ends of the square wave generating capacitor can be smoothly formed without obvious lag or distortion.
[0069] In practical applications, reference Figure 5 As shown, the midpoint of the high level of the pulse signal of the MOS tube U1 and the MOS tube U2 is aligned with the midpoint of the low level of the pulse signal of the MOS tube U3 and the MOS tube U4 (that is, the time points are the same), and the midpoint of the low level of the pulse signal of the MOS tube U1 and the MOS tube U2 is aligned with the midpoint of the high level of the pulse signal of the MOS tube U3 and the MOS tube U4.
[0070] It should be noted that in the process of generating an AC square wave signal, the square wave generating capacitor needs to meet the limit requirements for the charging and discharging time of the square wave generating capacitor in the above embodiment. In this case, if an AC square wave signal of different frequencies is used to represent the data 1 and the data 0 in the coding value, since the frequency of the AC square wave signal is constantly changing, it is necessary to adjust the parameters in the signal transmitting module so that the charging and discharging time of the square wave generating capacitor meets the above Δ limit requirements, or it is necessary to adjust the signal duty ratios of the MOS tubes U1, U2, U3, and U4 to meet the above Δ limit requirements.
[0071] Based on this, in one embodiment, in the process of generating an AC square wave signal corresponding to a coding value, the data 1 in the coding value is represented by at least two consecutive AC square wave signals with a preset fixed frequency, and the data 0 in the coding value is represented by an inconvenient level with a set duration, that is, an AC square wave signal with a preset fixed frequency will be generated at both ends of the square wave generating capacitor, or an output of a constant level.
[0072] like Figure 6As shown, Figure 6 The AC square wave signals corresponding to data bit 1 and data bit 0 are shown. Taking the 200KHz AC square wave signal representing data bit 1 as an example, the generation process of the AC square wave signal of data bit 1 is described.
[0073] The 200KHz AC square wave signal means that the signal cycle is 5 microseconds, and each cycle is divided into two parts, with the high level and low level of the square wave each occupying half of the time, that is, 2.5 microseconds. First, a control signal 1 is generated, which makes the MOS tubes U1 and U3 in the on state, and makes the MOS tubes U2 and U4 in the off state, so that the upper end of the square wave generating capacitor is connected to the power supply VCC, and the lower end is grounded, and the voltage on the square wave generating capacitor is positive, outputting a high level, and maintaining this state for 2.5 microseconds. After 2.5 microseconds, a control signal 2 is generated, which makes the MOS tubes U2 and U4 in the on state, and makes the MOS tubes U1 and U3 in the off state, so that the upper end of the square wave generating capacitor is grounded, and the lower end is connected to the power supply VCC, resulting in the voltage at both ends of the square wave generating capacitor being reversed, generating a low level of the square wave, and maintaining this state for 2.5 microseconds. In this way, a 200KHz AC square wave signal for representing data bit 1 will be generated every 5 microseconds.
[0074] Taking the 5 microseconds constant level representing data bit 0 as an example, the generation process of the AC square wave signal of data bit 0 is explained.
[0075] Generate control signal 3, which can make MOS tube U1, MOS tube U2, MOS tube U3 and MOS tube U4 all in the cut-off state, so that the voltage across the square wave generating capacitor is 0, thereby generating a constant level of 0 voltage, and maintaining this state for 3 microseconds, thereby completing the output of the AC square wave signal of data bit 0.
[0076] In the above embodiment, during the AC square wave generation process, there is only one AC square wave signal with a fixed frequency, and the frequency of the AC square wave signal does not need to be repeatedly changed. Therefore, for the above limit requirement of Δ, there is no need to repeatedly adjust the parameters of the signal transmission module.
[0077] In one embodiment, the code value is at least one group, and each group of code values includes a synchronization code, a data code located after the synchronization code, and a check code located after the data code. Figure 7 As shown, Figure 7 A schematic diagram of the data structure of a set of coded values is shown, the unit of the coded value is byte, including 3-bit synchronization code ( Figure 7 SYNC), 8-bit data encoding ( Figure 7 Bit 0-7 in the Figure 7P in ), a total of 12 bits. Among them, the synchronization code is composed of a 1.5-bit wide start bit 1 and a 1.5-bit wide start bit 0, which is used to indicate the start of data transmission and has a triggering effect. Assuming that the transmission rate is 10Kb / s, each bit of data 1 takes 100 microseconds during transmission. Assuming that the frequency of the AC square wave signal generated at both ends of the square wave generating capacitor is 100KHz, the duration of each cycle can be calculated to be 10 microseconds through the frequency. Since each data bit 1 takes 100 microseconds and each AC square wave cycle is 10 microseconds, the number of AC square wave cycles that can be included in the time of a data bit 1 is 10, which means that when transmitting a data bit 1, an AC square wave signal containing 10 complete cycles needs to be generated at both ends of the square wave generating capacitor. The synchronization code contains a 1.5-bit wide start bit 1, that is, when transmitting the start bit 1 in the synchronization code, an AC square wave signal containing 15 complete cycles needs to be generated at both ends of the square wave generating capacitor.
[0078] The data code is obtained based on the code of the data to be sent, indicating the data that actually needs to be transmitted. The check code is mainly used to verify the correctness of the data. A variety of check methods can be used to set the check code. For example, a parity check code can be used as the check code. If the number of data bits 1 in the data code is an odd number, the check code is set to 1. If the number of data bits 0 in the data code is an even number, the check code is set to 0. By setting the check code after the data code, the data can be verified after the data is transmitted, thereby improving the accuracy of data transmission and reducing the bit error rate.
[0079] Step S103 , sending the AC square wave signal to the power line through a coupling capacitor, and transmitting through the power line.
[0080] Here, the AC square wave signal is sent to the power line by means of a coupling capacitor. In practical applications, the coupling capacitor in the signal transmission module (i.e. Figure 3 C4 in the figure realizes the transmission of AC square wave signal. The coupling capacitor is used to couple the AC signal to the power line and prevent the transmission of DC component, thereby improving the transmission quality of the signal.
[0081] When the AC square wave signal corresponding to the coding value passes through the coupling capacitor, the AC square wave signal is coupled to the power line to form a power line carrier signal, and then the AC square wave signal is transmitted to the drilling instrument through the power line with the power line carrier signal, so that the drilling instrument can use the power line to meet the power demand while also meeting the signal transmission demand through the power line.
[0082] In this embodiment, the AC square wave signal is transmitted to the power line by means of capacitive coupling, so there is no need to consider the circuit matching and tuning issues of the high-frequency signal; moreover, the electromagnetic waves radiated outward during operation are relatively small, and it is not easy to interfere with the surrounding electromagnetic equipment. The environmental electromagnetic waves will not directly affect the capacitively coupled signal waveform, so it is not easily interfered by the surrounding electromagnetic equipment, thereby improving the signal integrity, stability and transmission quality.
[0083] In one embodiment, Figure 8 As shown, Figure 8 A schematic diagram of a flow chart for processing a received signal is shown.
[0084] Step S301, receiving an AC square wave signal on a power line, filtering and shaping the AC square wave signal to obtain a positive half-axis square wave signal.
[0085] The capacitive coupling communication system can receive the AC square wave signal transmitted by the drilling instrument based on the power line through capacitive coupling, wherein the capacitive coupling utilizes the characteristic of the capacitor supporting the passage of the AC signal to transmit the signal and blocks the DC signal, thereby obtaining the AC square wave signal transmitted by the drilling instrument.
[0086] Here, the capacitive coupling communication system can both transmit the AC square wave signal to the power line through capacitive coupling and receive the AC square wave signal on the power line through capacitive coupling, that is, realize the signal transmission between the signal transmitting module and the signal receiving module and the power line through capacitive coupling.
[0087] In practical applications, although capacitive coupling signals are not prone to mutual interference with surrounding electromagnetic devices, on the one hand, parasitic capacitance may form between any two conductors in high-frequency circuits, which is particularly disadvantageous in capacitive coupling systems because parasitic capacitance will introduce additional noise and signal attenuation, reducing signal integrity; on the other hand, capacitive coupling is highly sensitive to the surrounding electric field and is easily interfered by stray electric fields, affecting the transmission quality and stability of the signal. Therefore, the received AC square wave signal may have problems such as signal attenuation, noise interference and frequency distortion.
[0088] Based on this, before decoding the AC square wave signal, the AC square wave signal is filtered to remove noise and unnecessary frequency components in the AC square wave signal, wherein an RC filter circuit can be used to filter the AC square wave signal.
[0089] After filtering, the AC square wave signal is shaped into a square wave signal of the positive half axis, which can further reduce noise.
[0090] Step S302, comparing the positive half-axis square wave signal with a set reference voltage, and outputting a square wave signal that meets the set requirements according to the comparison result.
[0091] After filtering and shaping, the received AC square wave signal may still have certain distortion, and after transmission and coupling, the rising and falling edges of the AC square wave signal may not be steep enough, which is manifested as blurred edge transition of the signal or insufficient signal amplitude. The AC square wave signal needs to be further shaped to restore the ideal square wave shape.
[0092] Here, the positive semi-axis square wave signal is compared with the set reference voltage, wherein the reference voltage determines the threshold at which the square wave signal is triggered, and the reference voltage can be set as needed. After comparing the positive semi-axis square wave signal with the set reference voltage, a comparison result is obtained, wherein when the positive semi-axis square wave signal is lower than the reference voltage, a low level is output accordingly, and when the positive semi-axis square wave signal is higher than the reference voltage, a high level is output accordingly, so that the positive semi-axis square wave signal can be changed accordingly according to the comparison result, and finally a shaped square wave signal is obtained, which is more accurate and regular, and can meet the signal requirements of the downstream end, so that the signal can be accurately decoded to obtain more accurate data.
[0093] In the above embodiment, the data to be transmitted is encoded to obtain a corresponding coding value, and a control signal is generated. The control signal can switch the polarity of the two ends of the square wave generating capacitor, and an AC square wave signal corresponding to the coding value is generated at both ends of the square wave generating capacitor according to the control signal. The AC square wave signal is then coupled to the power line and transmitted through the power line, thereby enabling signal transmission even when the power line provides power, and the generation of the AC square wave signal will not be affected by the power supply voltage of the power line, thereby improving the stability, integrity and transmission quality of the signal.
[0094] In one embodiment, a capacitive coupling communication device is provided, referring to Fig. 9 As shown, the capacitive coupling communication device 900 is applied to a capacitive coupling communication system. The capacitive coupling communication device 900 may include: an encoding module 401 , a square wave generating module 402 , a signal sending module 403 , a signal receiving module 404 and a signal processing module 405 .
[0095] The encoding module 401 is used to encode the data to be sent to obtain a corresponding encoding value;
[0096] The square wave generating module 402 is used to generate a control signal, and generate an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal; the control signal is used to switch the polarity of both ends of the square wave generating capacitor; the square wave generating capacitor is a component in the signal transmitting module of the capacitive coupling communication system;
[0097] The signal sending module 403 is used to send the AC square wave signal to the power line through a coupling capacitor, and transmit it through the power line.
[0098] In one embodiment, the square wave generating module 402 is specifically used to select the working loop of the square wave generating capacitor in the first loop and the second loop according to the control signal; wherein, in the first loop, the first end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U1, and the second end of the square wave generating capacitor is grounded through the MOS tube U3; in the second loop, the first end of the square wave generating capacitor is grounded through the MOS tube U2, and the second end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U4.
[0099] In one embodiment, the square wave generating module 402 is specifically used to generate a first control signal to make the MOS transistors in the first loop and the second loop in a cut-off state;
[0100] A second control signal is generated to turn on the MOS transistor in one of the first loop and the second loop, and turn off the MOS transistor in the other loop.
[0101] In one embodiment, the control signal includes a gate control signal of the MOS tube U1, a gate control signal of the MOS tube U2, a gate control signal of the MOS tube U3 and a gate control signal of the MOS tube U4; wherein the turn-off delays of the MOS tube U1, the MOS tube U2, the MOS tube U3 and the MOS tube U4 are all less than the charging and discharging time of the square wave generating capacitor; the charging and discharging time of the square wave generating capacitor is determined based on the duty ratio of the gate control signal of the MOS tube U1 and the gate control signal of the MOS tube U4, the duty ratio of the gate control signal of the MOS tube U2 and the gate control signal of the MOS tube U3 and the coding frequency.
[0102] In one embodiment, the square wave generation module 402 is specifically used to represent the data 1 in the coding value using at least two continuous AC square wave signals, and to represent the data 0 in the coding value using a constant level of a set duration; wherein the AC square wave signal has a preset fixed frequency.
[0103] In one embodiment, the code value is at least one group, and each group of code values includes a synchronization code, a data code located after the synchronization code, and a check code located after the data code.
[0104] In one embodiment, the capacitive coupling communication device 900 also includes a signal receiving module 404 and a signal processing module 405, wherein the signal receiving module 404 is used to receive an AC square wave signal on the power line; the signal processing module 405 is used to filter and shape the AC square wave signal to obtain a positive half-axis square wave signal; the positive half-axis square wave signal is compared with a set reference voltage, and based on the comparison result, a square wave signal that meets the set requirements is output.
[0105] For the specific definition of the capacitive coupling communication device 900, please refer to the definition of the capacitive coupling communication method above, which will not be repeated here. Each module in the above-mentioned capacitive coupling communication device 900 can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.
[0106] In one embodiment, a capacitive coupling communication system is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor implements a capacitive coupling communication method when executing the computer program.
[0107] In one embodiment, a computer storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, a capacitive coupling communication method is implemented.
[0108] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.
[0109] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
[0110] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0111] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0112] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.
Claims
1. A capacitive coupling communication method, characterized in that: Applied to a capacitive coupling communication system, the method comprises: Encode the data to be sent to obtain the corresponding encoding value; Generate a control signal, and generate an AC square wave signal corresponding to the encoding value at both ends of the square wave generating capacitor according to the control signal; the control signal is used to switch the polarity of both ends of the square wave generating capacitor; the square wave generating capacitor is a component in the signal transmitting module of the capacitive coupling communication system; The AC square wave signal is sent to the power line by means of coupling capacitors and transmitted through the power line.
2. The capacitive coupling communication method according to claim 1, characterized in that: Generating an AC square wave signal corresponding to the coding value at two ends of a square wave generating capacitor according to the control signal includes: According to the control signal, the working loop of the square wave generating capacitor is selected in the first loop and the second loop; wherein, in the first loop, the first end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U1, and the second end of the square wave generating capacitor is grounded through the MOS tube U3; in the second loop, the first end of the square wave generating capacitor is grounded through the MOS tube U2, and the second end of the square wave generating capacitor is connected to the power supply VCC through the MOS tube U4.
3. The capacitive coupling communication method according to claim 2, characterized in that: Generating an AC square wave signal corresponding to the coding value at two ends of a square wave generating capacitor according to a control signal includes: Generate a first control signal to put the MOS transistors in the first loop and the second loop into a cut-off state; A second control signal is generated to make the MOS transistor of one of the first loop and the second loop in a conducting state, and the MOS transistor of the other loop in a cutting-off state.
4. The capacitive coupling communication method according to claim 2, characterized in that: The control signal includes a gate control signal of the MOS tube U1, a gate control signal of the MOS tube U2, a gate control signal of the MOS tube U3 and a gate control signal of the MOS tube U4; wherein, the turn-off delays of the MOS tubes U1, U2, U3 and U4 are all less than the charging and discharging time of the square wave generating capacitor; the charging and discharging time of the square wave generating capacitor is determined based on the duty ratio of the gate control signal of the MOS tube U1 and the gate control signal of the MOS tube U4, the duty ratio of the gate control signal of the MOS tube U2 and the gate control signal of the MOS tube U3 and the coding frequency.
5. The capacitive coupling communication method according to claim 1, characterized in that: Generating an AC square wave signal corresponding to the coding value at two ends of a square wave generating capacitor according to a control signal includes: The data 1 in the coding value is represented by at least two continuous AC square wave signals, and the data 0 in the coding value is represented by a constant level of a set duration; wherein the AC square wave signal has a preset fixed frequency.
6. The capacitive coupling communication method according to claim 5, characterized in that: The coding value is at least one group, and each group of the coding values includes a synchronization code, a data code located after the synchronization code, and a check code located after the data code.
7. The capacitive coupling communication method according to claim 1, characterized in that: The method further comprises: Receiving an AC square wave signal on the power line, and performing filtering and shaping processing on the AC square wave signal to obtain a positive half-axis square wave signal; The positive half-axis square wave signal is compared with a set reference voltage, and based on the comparison result, a square wave signal that meets the set requirements is output.
8. A capacitive coupling communication device, applied to a capacitive coupling communication system, the device comprising: The encoding module is used to encode the data to be sent to obtain the corresponding encoding value; A square wave generating module, used to generate a control signal, and generate an AC square wave signal corresponding to the coding value at both ends of the square wave generating capacitor according to the control signal; the control signal is used to switch the polarity of both ends of the square wave generating capacitor; the square wave generating capacitor is a component in the signal transmitting module of the capacitive coupling communication system; The signal sending module is used to send the AC square wave signal to the power line through a coupling capacitor and transmit it through the power line.
9. A capacitive coupling communication system, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the capacitive coupling communication method according to any one of claims 1 to 7 is implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the capacitive coupling communication method according to any one of claims 1 to 7 is implemented.