Real-time pressure detection system and method based on advanced physical layer technology

Abstract

The invention relates to a real-time pressure detection system and method based on an advanced physical layer technology. The APL communication processing module extracts an energy signal from an APL network, and the power management module converts the energy signal into a voltage required by each module. And the main control module calibrates a local clock to keep time synchronization according to the system time in the monitoring server data message received by the APL communication processing module. And the main control module controls the data acquisition module to acquire pressure signals in real time according to a specified frequency according to a control instruction of the monitoring server. The main control module combines collected data and time into a data message, and the APL communication processing module constructs the data message into a data frame and transmits the data frame to a monitoring server through an APL communication network. The problem that the pressure detection precision is reduced due to the fact that the pressure detection signal is attenuated after being transmitted for a long distance is solved, and the pressure sensor has the advantages of being low in cost, high in measurement precision, high in real-time performance, capable of being applied to flammable and explosive dangerous environments such as petrochemical engineering and the like and wide in application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial automation and process control, and particularly relates to a real-time pressure detection method and system based on advanced physical layer technology. Background Art

[0002] In the petrochemical production process, high temperature, high pressure, and flammable and explosive media are involved. Any abnormal pressure may cause equipment damage, leakage, or even explosion, leading to serious safety accidents. Real-time pressure detection can timely capture pressure changes and provide early warning information for operators, so as to take effective measures to avoid accidents. Secondly, pressure is one of the key parameters reflecting the operating state of equipment. Real-time monitoring of pressure signals helps to optimize the production process, improve the operating efficiency of equipment, and reduce energy consumption and costs.

[0003] Currently, traditional pressure detection methods, such as piezoresistive pressure detection instruments, capacitive pressure detection instruments, fiber optic pressure detection instruments, ceramic pressure detection instruments, and other various pressure detection instruments, use the principle of converting pressure signals into various types of physical signals for remote transmission. The above methods have a wide measurement range, high stability, and can operate stably in flammable and explosive environments. However, the signal will attenuate after remote transmission, resulting in a decrease in the acquisition accuracy of the pressure signal. In addition, the real-time performance of the pressure signals collected by the above methods is relatively low, and it cannot provide strong data support for improving production efficiency and fault prediction. The intelligent pressure transmitter uses protocols such as HART and PROFIBUS to convert the pressure signals collected on-site into digital signals and remotely transmit them to the monitoring system in real time, which can effectively improve the accuracy and real-time performance of pressure signal acquisition. However, various complex conversion circuits are integrated in the intelligent pressure transmitter, and it is easy to generate electrical sparks due to failures, thus causing danger.

[0004] Therefore, there is an urgent need for a highly accurate real-time pressure detection system and method that is applicable to flammable and explosive environments and intrinsically safe. Summary of the Invention

[0005] Aiming at the above deficiencies in the prior art, the purpose of the present invention is to provide a real-time pressure detection method and system based on advanced physical layer technology, mainly used to design and implement a method and system that can collect pressure signals in the production process in real time and remotely transmit them in flammable and explosive scenarios such as petrochemical industry, providing data technology support for the safety monitoring and production efficiency improvement of the petrochemical production process.

[0006] First, the APL communication processing module extracts the energy signal through the APL communication transmission network. The power management module converts the energy signal into the voltage required for the normal operation of each module. Then, the main control module adjusts the local clock according to the system time in the data packets regularly sent by the monitoring server received by the APL communication processing module, so that the time of this system is consistent with that of the monitoring server. Next, the main control module controls the high-precision data acquisition module to collect the pressure signal in real time according to the data acquisition frequency in the control instruction sent by the monitoring server. Finally, the main control module combines the collected data and the acquisition time into a data packet, forms a data frame through the APL communication processing module, converts it into an APL transmission signal, and then transmits it to the APL communication transmission network to realize the real-time monitoring of the pressure signal.

[0007] The technical solution adopted by the present invention to achieve the above object provides a real-time pressure detection system based on advanced physical layer technology, including:

[0008] The APL communication processing module, which uses an advanced physical layer communication chip, is used to capture the energy signal and data signal from the APL communication network, transmit the energy signal to the power management module to supply power to the whole system, extract the control instruction in the data signal and transmit it to the main control module, and after forming the data packet transmitted from the main control module into a data frame, convert it into an APL communication signal and transmit it to the APL communication network;

[0009] The power management module is used to convert the energy signal transmitted by the APL communication processing module into a 3.3V voltage signal required for the operation of the main control module and the data acquisition module;

[0010] The data acquisition module is used to directly convert the 0-100mV weak voltage signal output by the pressure sensor into a digital signal and transmit it to the main control module according to the sampling frequency read by the main control module from the control instruction from the monitoring server;

[0011] The main control module, which uses an embedded processor, is used to adjust the local clock according to the system time in the management packet regularly sent by the monitoring server, so that the local time of the real-time pressure detection system based on advanced physical layer technology is consistent with the time of the monitoring server; according to the control instruction sent by the monitoring server, control the data acquisition module to collect data according to the specified sampling frequency, and finally combine the pressure sensor signal data collected by the data acquisition module and the data acquisition time into a data packet, and transmit it to the APL communication network through the APL communication module.

[0012] The APL communication processing module uses an Ethernet chip based on the advanced physical layer to extract the energy signal and data signal from the twisted pair electrical signal of the APL communication network, and convert the data based on the Ethernet communication protocol into a twisted pair electrical signal and transmit it to the APL communication network.

[0013] The APL communication processing module adopts a first common-mode filter;

[0014] Two input ends of the first common-mode filter are connected to the APL communication network through twisted pairs and are also connected to the power management module; two input ends of the first common-mode filter are respectively grounded through a first diode and a second diode; a positive output end of the first common-mode filter serves as a TXN_ADI node after passing through a capacitor C19 and a resistor R7, and the positive output end of the first common-mode filter serves as an RXN_ADI node after passing through the capacitor C19 and a resistor R8; a negative output end of the first common-mode filter serves as an RXP_ADI node after passing through a capacitor C20 and a resistor R11, and the positive output end of the first common-mode filter serves as a TXP_ADI node after passing through the capacitor C20 and a resistor R12; the TXN_ADI node, the RXN_ADI node, the RXP_ADI node, and the TXP_ADI node are respectively connected to differential output ends TXN_ADI, differential input ends RXN_ADI, differential input ends RXP_ADI, and differential output ends TXP_ADI of the main control module; a resistor R10 is connected between the TXN_ADI node and the RXP_ADI node, and a resistor R9 is connected between the RXN_ADI node and the TXP_ADI node;

[0015] The first common-mode filter separates data signals and energy signals in the transmitted signal. The energy signals are transmitted to the power management module through twisted pairs P+ and P- for processing, and the data signals are transmitted to the inside of the main control chip through pins TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI of the main control chip for data processing; among them, the resistor R7, the resistor R8, and the capacitor C19 are connected in parallel to form a first filter circuit for filtering high-frequency noise in the signals input to the TXN_ADI and RXN_ADI pins, the resistor R11, the resistor R12, and the capacitor C20 are connected in parallel to form a second filter circuit for filtering high-frequency noise in the signals input to the TXP_ADI and RXP_ADI pins, and the resistor R9 and the resistor R10 are responsible for pulling down the signals to ensure that when the signals of the TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI pins are in an idle state, they remain at a low level.

[0016] The power management module includes a single-phase rectifier, a second common-mode filter, an isolated DC-DC power module chip, and a linear voltage regulator connected in sequence. The positive input terminal and the negative input terminal of the single-phase rectifier are connected to the APL communication processing module through twisted pair P+ and twisted pair P-, respectively. The positive input terminal and the negative input terminal of the single-phase rectifier are grounded through a third diode and a fourth diode, respectively. A capacitor C1 and a capacitor C2 are connected in parallel between the two voltage output terminals of the second common-mode filter. A capacitor C3 and a capacitor C4 are connected in parallel between the two output terminals of the isolated DC-DC power module chip. A capacitor C5 and a capacitor C6 are connected in parallel between the two output terminals of the linear voltage regulator.

[0017] When the twisted pair P+ and P- terminals are connected to the APL communication transmission network through the APL communication processing module, the third diode and the fourth diode are in the cut-off state, and the energy signal can enter the power management module. When the twisted pair P+ and P- terminals are connected in the reverse direction, the third diode and the fourth diode are in the conducting state, and the energy signal is led to the ground to avoid damaging the power management module.

[0018] The single-phase rectifier converts the energy signal in the APL communication network into a voltage, and then the second common-mode filter further processes the converted voltage to reduce the ripple interference in the DC voltage. An isolated DC-DC power module chip is used to isolate the voltage converted by the single-phase rectifier to ensure that when a short-circuit fault occurs in the input voltage of the power management module, it does not affect the operation of other modules in the system.

[0019] The voltage isolated by the isolated DC-DC power module chip is 5V. A linear voltage regulator is used to convert the 12V voltage into 3.3V voltage to supply power to the main control module and the data acquisition module in the system.

[0020] Capacitors C1, C2, C3, C4, C5, and C6 are used to remove the AC interference between the voltage input signal and the voltage output signal of the second common-mode filter, the isolated DC-DC power module chip, and the linear voltage regulator. Among them, the capacitance values of C1, C3, and C5 are 22uF, which are used to remove the high-frequency AC interference in the voltage input signal and the voltage output signal, and the capacitance values of C2, C4, and C6 are 0.1uF, which are used to remove the low-frequency AC interference in the voltage input signal and the voltage output signal.

[0021] A real-time pressure detection method based on advanced physical layer technology includes the following steps:

[0022] System power supply: For the APL communication transmission network, the energy signal is extracted by the APL communication processing module and supplied to the power management module; after the power management module converts the energy signal into the voltages required for the main control module and the data acquisition module to work, it supplies power to the main control module and the data acquisition module respectively;

[0023] Time synchronization: After the APL communication processing module receives the data signal containing the system time from the APL communication transmission network, it extracts the system time and transmits it to the main control module, and the main control module adjusts the local clock according to the received system time; the system time is regularly transmitted to the APL communication transmission network by the monitoring server through data packets;

[0024] Pressure sensor signal acquisition: The main control module controls the data acquisition module to collect the output signal of the pressure sensor according to the control instruction in the control packet sent by the monitoring server received through the APL communication processing module at the data acquisition frequency in the control instruction;

[0025] Transmission of the collected data packet: The data acquisition module transmits the collected data to the main control module, the main control module forms a data packet with the collected data and the acquisition time and transmits it to the APL communication processing module, and the APL communication processing module forms the data packet into a data frame and converts it into an APL transmission signal, and sends it to the monitoring server through the APL communication transmission network.

[0026] The present invention is a real-time pressure detection method and system based on advanced physical layer technology, and it has the following beneficial effects and advantages:

[0027] 1. High measurement accuracy. In the method of the present invention, by directly converting the weak voltage signal output by the pressure sensor into a voltage signal by using a 24-bit high-precision analog-to-digital converter, and then using the APL communication processing module based on advanced physical layer technology to convert the pressure acquisition digital signal into a data packet for long-distance transmission, it can effectively avoid the attenuation of the signal and the reduction of the acquisition accuracy of the pressure signal caused by the long-distance transmission of the acquisition signal.

[0028] 2. High real-time performance. In the method of the present invention, on the one hand, by using a high-speed analog-to-digital converter with a single sampling time less than 2 ms, the influence of the data acquisition process delay on the data real-time performance is reduced. On the other hand, by forming a data packet with the data acquisition time and the collected data for transmission, the influence of the transmission delay of the data packet in the APL communication network on the data real-time performance of the collected data is avoided.

[0029] 3. Low cost. The method of the present invention uses an APL communication processing module based on advanced physical layer technology, which can receive separated energy signals and data signals from the APL communication network and transmit them to the power management module and the main control module respectively, effectively reducing the deployment of power cables and communication cables in the overall system, thereby reducing the system deployment cost.

[0030] 4. Intrinsic safety. The power management module in the method of the present invention is designed and implemented using low-power components that meet the requirements of intrinsic safety. The output voltage of the power management module is less than or equal to 3.3V, and the output current is less than 100mA, meeting the requirements of intrinsic safety, thus ensuring that the method of the present invention can still be used in dangerous environments such as petrochemical industries where flammable and explosive substances exist. Description of the Drawings

[0031] Figure 1 is a block diagram of an implementation example of a real-time pressure detection system based on advanced physical layer technology in the method of the present invention;

[0032] Figure 2 is a circuit schematic diagram of the power management module of the real-time pressure detection system based on advanced physical layer technology in the method of the present invention;

[0033] Figure 3 is a circuit schematic diagram of the APL communication processing module of the real-time pressure detection system based on advanced physical layer technology in the method of the present invention;

[0034] Figure 4 is a schematic diagram of the data frame format in the method of the present invention. Detailed Embodiments

[0035] The present invention will be further described in detail below with reference to the drawings and implementation examples.

[0036] A real-time pressure detection method based on advanced physical layer technology, which is used to collect pressure signals in the production process in real time and remotely transmit them in flammable and explosive scenarios such as petrochemical industries, and a method and system thereof, including the following steps:

[0037] System power supply. The advanced physical layer (APL) communication processing module extracts energy signals through the APL communication transmission network and supplies them to the power management module; after the power management converts the energy signals into voltages required for the operation of other functional modules, it supplies power to them respectively, enabling each functional module to operate stably and normally;

[0038] Time synchronization. The monitoring server regularly transmits the system time to the APL communication transmission network through data packets. After the APL communication processing module receives the data packet containing the system time from the APL communication transmission network, it extracts the system time and transmits it to the main control module, and the main control module adjusts the local clock according to the received system time;

[0039] Pressure sensor signal acquisition: The main control module controls the high-precision data acquisition module to collect the output signal of the pressure sensor according to the control instruction in the control message sent by the monitoring server at the data acquisition frequency in the control instruction;

[0040] Transmission of the collected data message: The high-precision data acquisition module transmits the collected data to the main control module. The main control module combines the collected data and the acquisition time into a data message and transmits it to the APL communication processing module. The APL communication processing module forms the data message into a data frame and converts it into an APL transmission signal, and sends it to the monitoring server through the APL communication transmission network.

[0041] The system power supply extracts the energy signal from the APL communication transmission network through the APL communication processing module. After the power management module converts the received energy signal into the voltage required for the operation of other modules, it supplies power to each module. Compared with the traditional separate power supply of an external power source, it can reduce the layout of the system's power cables.

[0042] The time synchronization is achieved by receiving the data message containing the system time regularly sent by the monitoring server, extracting the system time in the data message, and the main control module adjusts the local clock according to the system time, so that the system and the monitoring server are on the same time basis.

[0043] The pressure sensor signal acquisition directly collects the 0-100mV weak voltage signal output by the pressure sensor through the high-precision data acquisition module using a high-precision analog-to-digital converter, thus avoiding introducing errors and reducing the signal acquisition accuracy due to secondary processing of the pressure sensor signal.

[0044] For the pressure sensor signal acquisition, the main control module can adjust the sampling frequency of the high-precision data acquisition module in real time according to the data acquisition frequency in the control instruction sent by the monitoring server.

[0045] For the transmission of the collected data message, after receiving the collected data transmitted by the high-precision data acquisition module, the main control module records the data acquisition time, and combines the data acquisition time and the collected data into a data message and sends it to the APL communication processing module. The APL communication processing module forms the data message into a data frame and converts it into an APL transmission signal, and sends it to the monitoring server through the APL communication transmission network.

[0046] A real-time pressure detection system based on advanced physical layer technology, including the following parts:

[0047] The APL communication processing module uses an advanced physical layer (APL) communication chip to capture energy signals and communication signals from the APL communication network. It transmits the energy signals to the power management module to supply power to the entire system, extracts the control messages in the communication signals and transmits them to the main control module. Additionally, after assembling the data messages transmitted from the main control module into data frames in the APL communication processing module, it converts them into APL communication signals and transmits them to the APL communication network;

[0048] The power management module converts the energy signals transmitted from the APL communication processing module into 3.3V voltage signals required for the operation of the main control module and the high-precision data acquisition module;

[0049] The high-precision data acquisition module takes a 24-bit high-precision analog-to-digital converter as the core and directly converts the 0-100mV weak voltage signal output by the pressure sensor into a digital signal and transmits it to the main control module according to the sampling frequency read from the control instructions sent by the main control module from the monitoring server;

[0050] The main control module uses an embedded processor. First, it adjusts the local clock according to the system time in the management messages regularly sent by the monitoring server to make the local time of the real-time pressure detection system based on the advanced physical layer technology consistent with the time of the monitoring server. Then, according to the control instructions sent by the monitoring server, it controls the high-precision data acquisition module to perform data acquisition at the specified sampling frequency. Finally, it assembles the pressure sensor signal data collected by the high-precision data acquisition module and the data acquisition time into data messages and transmits them to the APL communication network through the APL communication module.

[0051] Figure 1It is a specific application example of a real-time pressure detection system based on advanced physical layer technology; First, the APL communication processing module of the system receives energy signals from the APL communication network. After the power management module converts the energy signals into voltage, it powers each functional module in the system. The main control module performs different operations according to the types of messages sent by the monitoring server received by the APL communication processing module from the APL communication network. When the main control module receives the clock message containing the system time information regularly sent by the monitoring server, the main control module reads the system time in the clock message and adjusts the local clock of the system accordingly, so that the system and the monitoring server are on the same clock reference. When the main control module receives the control instruction message containing the data sampling frequency of the pressure signal sent by the monitoring server, the main control module adjusts the high-precision data acquisition module in real time according to the data sampling frequency in the control instruction. The high-precision data acquisition module collects the weak voltage signal output by the pressure sensor according to the sampling frequency in the control instruction and converts it into a digital signal and transmits it to the main control module. The main control module combines the data collected by the high-precision data acquisition module and the data acquisition time into a data message and transmits it to the APL communication processing module. Finally, after the APL communication processing module assembles the data message into a data frame, it converts it into an APL communication signal and transmits it to the APL communication network. The following combines the actual real-time pressure detection and transmission process to specifically introduce each functional module, and combines each functional module to introduce the specific implementation process of the real-time pressure detection method based on advanced physical layer technology in the method of the present invention in detail.

[0052] Power management module: The power management module is mainly responsible for converting the energy signals in the APL communication transmission network into the voltages required for the operation of each module in the system. The APL communication network is constructed based on twisted pair cables, and the energy signals and data signals are transmitted on the twisted pair cables at the same time. Figure 2This is the specific design circuit schematic diagram of the power management module of this system. First, the power management module receives transmission signals from the APL communication network through the twisted pair P+ and twisted pair P- terminals. The diode J60CA connected to the twisted pair P+ and twisted pair P- terminals plays a role in preventing reverse connection protection. When the twisted pair P+ and twisted pair P- terminals are normally connected to the APL communication transmission network, the diode J60CA is in the cut-off state, and the energy signal can enter the subsequent circuit normally. When the twisted pair P+ and twisted pair P- terminals are reversely connected, the diode J60CA is in the conducting state, and the energy signal is introduced into the ground to avoid damaging the subsequent circuit; the self-recovery fuse JK-nSMD010 is used to actively fuse and protect the subsequent circuit when the current in the energy signal is too large. After the current in the energy signal returns to normal, the self-recovery fuse JK-nSMD010 automatically conducts; the single-phase rectifier ABS210 in the power management module is responsible for converting the energy signal in the APL communication network into voltage. Since there are large ripples in the voltage converted by the single-phase rectifier ABS210, the 744242471 common-mode filter is selected to further process the voltage converted by the rectifier ABS210 to reduce the ripple interference in the DC voltage; in order to avoid the impact of faults such as excessive input voltage and short circuit in the power management module on other modules of the system, the B0505S isolated DC-DC power module chip is selected for the power management module to isolate the voltage converted by the rectifier ABS210, so as to ensure that when a fault such as a short circuit occurs in the input voltage of the power management module, it will not affect the operation of other functional modules in the system; the working voltage of each main functional module in the system is 3.3V, and the voltage isolated by the B0505S isolated DC-DC power module chip is 5V. Therefore, the LM1117-3.3 linear voltage regulator is used to convert the 12V voltage into 3.3V voltage to supply power to each main functional module in the system; the functions of capacitors C1, C2, C3, C4, C5, and C6 are to remove the AC interference of the voltage input signal and voltage output signal of the above-mentioned each power chip. Among them, the capacitance values of C1, C3, and C5 are 22uF, which are mainly responsible for removing the high-frequency AC interference in the voltage input signal and voltage output signal, and the capacitance values of C2, C4, and C6 are 0.1uF, which are mainly responsible for removing the low-frequency AC interference in the voltage input signal and voltage output signal.

[0053] APL Communication Processing Module: The APL communication processing module is mainly responsible for receiving and separating the energy signal and data signal from the APL communication network, transmitting the energy signal to the power management module for voltage conversion, extracting the data packets in the data signal and transmitting them to the main control module, and assembling the data packets sent by the main control module into data frames and then converting them into twisted pair signals and transmitting them to the APL communication network. Figure 3This is the specific design circuit schematic diagram of the APL communication processing module of the system. First, the APL communication module receives transmission signals and energy signals from the APL communication network through the twisted pair P+ and twisted pair P- terminals. The diode J60CA connected to the twisted pair P+ and twisted pair P- terminals plays a role in preventing reverse connection protection. The common mode filter 744242471 separates the data signal and energy signal in the transmission signal. The energy signal is transmitted to the power management module through the twisted pair P+ and twisted pair P- terminals for processing. Then, the data signal is transmitted to the ADIN1100 chip based on the advanced physical layer Ethernet chip through the TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI pins for data processing. Among them, the resistors R7, R8, and the capacitor C19 are connected in parallel to form a filtering circuit, which is responsible for filtering out the high-frequency noise in the signals input to the TXN_ADI and RXN_ADI pins. The resistors R11, R12, and the capacitor C20 are connected in parallel to form a filtering circuit, which is responsible for filtering out the high-frequency noise in the signals input to the TXP_ADI and RXP_ADI pins. The resistors R9 and R10 are responsible for pulling down the signal to ensure that when the signals of the TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI pins are in the idle state, they remain at a low level.

[0054] In this system, the clock message data frame, control instruction message data frame sent by the monitoring server, and the data frame sent by the APL communication processing module are all constructed based on the 802.3 Ethernet communication protocol. The specific structure of the data frame is as Figure 4 shown, where Dst_MAC represents the MAC address of the data frame sending target; Src_MAC represents the MAC address of the data frame sending source; EtheType represents the data frame type, and 0x8657 is selected as the data frame type of this system; DataLength represents the data length of the data message Data segment in the data frame, and MsgType represents the type of the data message in the data frame. Among them, 0 represents the clock message, 1 represents the control instruction message, and 2 represents the data message. After receiving the data signal, the APL communication processing module first converts it into a data frame, and then extracts and transmits the data message in the data frame to the main control module; after receiving the data message sent by the main control module, the APL communication processing module forms a complete data frame according to the type, length, and sending object of the data message, and converts the formed data frame into a data signal and transmits it to the APL communication network through the twisted pair P+ and twisted pair P- terminals.

[0055] High-precision data acquisition module: The high-precision data acquisition module is mainly responsible for collecting the weak voltage signal of the pressure sensor according to the data acquisition frequency in the monitoring server control instruction. The high-precision data acquisition module is designed with the AD7794 high-precision, low-power 24-bit analog-to-digital converter of ADI Company as the core. The AD7794 analog-to-digital converter communicates with the main control module through the SPI bus, and collects data according to the sampling frequency in the monitoring server control instruction received by the main control module. The single conversion time of the AD7794 analog-to-digital converter is less than 2ms, which can effectively ensure the real-time performance of the collected data. In addition, to ensure the data acquisition accuracy of the weak voltage signal of the pressure sensor, the AD7794 analog-to-digital converter directly collects the weak voltage signal output by the pressure sensor. The pressure sensor selected in this system is a piezoresistive pressure sensor, which has the advantages of wide range, high sensitivity, low power consumption, and fast response speed. The piezoresistive pressure sensor outputs a weak voltage signal of 0-100mV, and the minimum resolution can reach 0.01mV after being converted into a digital signal by the AD7794 analog-to-digital converter, meeting the requirements for the detection accuracy of the pressure signal in the production process. And by converting the output signal of the pressure sensor into a digital signal for remote transmission, it can effectively avoid the signal attenuation caused by converting the output signal of the pressure sensor into a 4-20mA signal for remote transmission in the traditional method, thus reducing the occurrence of the phenomenon of reducing the pressure signal detection accuracy.

[0056] Main control module: The main control module is the core of the entire real-time pressure detection system based on advanced physical layer technology, and is responsible for controlling the high-precision data module, APL communication processing module, and local clock to complete the real-time acquisition and transmission function of the output signal of the pressure sensor. In this implementation example, the embedded processor of the main control module selects the STM32F407 model embedded microprocessor of STMicroelectronics. This model of processor has the advantages of powerful performance, stable and mature, and wide application in the industrial control field. And this model of processor supports many peripheral device interfaces, meeting the interface requirements of other modules of the entire system. The main control module realizes its functions in the form of event triggering. The following specifically introduces the specific functions executed by the main control module under different events:

[0057] 1) When the main control module receives the clock message sent by the monitoring server extracted by the APL communication processing module, the main control module reads the system time in the clock message. The system time sent by the monitoring server is 64 bits in total, 8 bytes, and the time unit is ns. The main control module replaces the original time information in the local clock register with the read system time, so that the real-time pressure detection system based on advanced physical layer technology is on the same clock reference as the monitoring server.

[0058] 2) When the main control module receives the control instruction message sent by the monitoring server extracted by the APL communication processing module, the main control module reads the sampling frequency in the control instruction message. The data length representing the sampling frequency is 32 bits, which is 4 bytes in total. The unit of the sampling frequency is Hz. The range of the sampling frequency in the control instruction sent by the monitoring server is 5 - 400 Hz. The main control module controls the high-precision data acquisition module through the SPI bus to collect the output signal of the pressure sensor according to the sampling frequency in the control instruction.

[0059] 3) When the main control module receives the pressure sensor data collected by the high-precision data acquisition module through the SPI bus, it reads and records the current moment t1 of the local clock. The data length of the acquisition moment t1 is 64 bits, which is 8 bytes in total, and the time unit is ns. Since the core AD7794 chip of the high-precision data acquisition module is a 24-bit analog-to-digital converter, the pressure sensor data collected and converted is 24 bits. The main control module performs a padding operation on the pressure sensor data collected by the high-precision data acquisition module, padding 8 bits in front of the pressure sensor data to form 32-bit pressure sensor data, which is 4 bytes in total. Then the main control module combines the padded pressure sensor data with the acquisition moment t1 to form a data message and transmits it to the APL communication processing module. The APL communication processing module assembles the data message into a data frame according to the Figure 4 shown data frame structure, and converts it into an APL communication signal and transmits it to the monitoring server through the APL communication network, finally realizing the real-time detection and remote transmission D of the on-site pressure.

Claims

1. A real-time pressure detection system based on advanced physical layer technology, characterized in that, Including: An APL communication processing module, which uses an advanced physical layer communication chip, is used to capture energy signals and data signals from the APL communication network, transmit the energy signals to the power management module to supply power to the entire system, extract the control instructions in the data signals and transmit them to the main control module, and after assembling the data packets transmitted from the main control module into data frames in the APL communication processing module, convert them into APL communication signals and transmit them to the APL communication network; A power management module, which is used to convert the energy signals transmitted by the APL communication processing module into 3.3V voltage signals required for the operation of the main control module and the data acquisition module; A data acquisition module, which is used to directly convert the 0-100mV weak voltage signal output by the pressure sensor into a digital signal and transmit it to the main control module according to the sampling frequency read by the main control module from the control instructions from the monitoring server; A main control module, which uses an embedded processor, is used to adjust the local clock according to the system time in the management packets regularly sent from the monitoring server, so that the local time of the real-time pressure detection system based on the advanced physical layer technology is consistent with the time of the monitoring server; According to the control instructions sent by the monitoring server, control the data acquisition module to perform data acquisition according to the specified sampling frequency, and finally assemble the pressure sensor signal data and the data acquisition time collected by the data acquisition module into a data packet, and transmit it to the APL communication network through the APL communication module.

2. The real-time pressure detection system based on advanced physical layer technology according to claim 1, characterized in that The APL communication processing module uses an Ethernet chip based on the advanced physical layer, which is used to extract energy signals and data signals from the twisted pair electrical signals of the APL communication network, and convert the data based on the Ethernet communication protocol into twisted pair electrical signals and transmit them to the APL communication network.

3. A real-time pressure detection system based on advanced physical layer technology according to claim 1 or 2, characterized in that, The APL communication processing module uses a first common mode filter; Two input terminals of the first common mode filter are connected to the APL communication network through twisted pairs and are also connected to the power management module; two input terminals of the first common mode filter are grounded through a first diode and a second diode respectively; the positive output terminal of the first common mode filter is used as the TXN_ADI node after passing through capacitor C19 and resistor R7, and the positive output terminal of the first common mode filter is used as the RXN_ADI node after passing through capacitor C19 and resistor R8; the negative output terminal of the first common mode filter is used as the RXP_ADI node after passing through capacitor C20 and resistor R11, and the positive output terminal of the first common mode filter is used as the TXP_ADI node after passing through capacitor C20 and resistor R12; the TXN_ADI node, RXN_ADI node, RXP_ADI node, and TXP_ADI node are respectively connected to the differential output terminal TXN_ADI, differential input terminal RXN_ADI, differential input terminal RXP_ADI, and differential output terminal TXP_ADI of the main control module; a resistor R10 is connected between the TXN_ADI node and the RXP_ADI node, and a resistor R9 is connected between the RXN_ADI node and the TXP_ADI node; The first common-mode filter separates the data signal and the energy signal in the transmitted signal. The energy signal is transmitted to the power management module through the twisted pair P+ and the twisted pair P- for processing. The data signal is transmitted to the inside of the main control chip through the TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI pins of the main control chip for data processing. Among them, the resistor R7, the resistor R8, and the capacitor C19 are connected in parallel to form a first filter circuit for filtering high-frequency noise in the signals input to the TXN_ADI and RXN_ADI pins. The resistor R11, the resistor R12, and the capacitor C20 are connected in parallel to form a second filter circuit for filtering high-frequency noise in the signals input to the TXP_ADI and RXP_ADI pins. The resistor R9 and the resistor R10 are responsible for pulling down the signal to ensure that when the signals of the TXN_ADI, RXN_ADI, RXP_ADI, and TXP_ADI pins are in the idle state, they remain at a low level.

4. A real-time pressure detection system based on advanced physical layer technology according to claim 1, characterized in that, The power management module includes a single-phase rectifier, a second common-mode filter, an isolated DC-DC power module chip, and a linear voltage regulator connected in sequence. The positive input terminal and the negative input terminal of the single-phase rectifier are respectively connected to the APL communication processing module through the twisted pair P+ and the twisted pair P-. The positive input terminal and the negative input terminal of the single-phase rectifier are respectively grounded through the third diode and the fourth diode. A capacitor C1 and a capacitor C2 are connected in parallel between the two voltage output terminals of the second common-mode filter. A capacitor C3 and a capacitor C4 are connected in parallel between the two output terminals of the isolated DC-DC power module chip. A capacitor C5 and a capacitor C6 are connected in parallel between the two output terminals of the linear voltage regulator. When the twisted pair P+ and the twisted pair P- are connected to the APL communication transmission network through the APL communication processing module, the third diode and the fourth diode are in the cut-off state, and the energy signal can enter the power management module. When the twisted pair P+ and the twisted pair P- are reversely connected, the third diode and the fourth diode are in the conducting state, and the energy signal is led to the ground to avoid damaging the power management module. The single-phase rectifier converts the energy signal in the APL communication network into a voltage, and then the second common-mode filter further processes the converted voltage to reduce the ripple interference in the DC voltage. An isolated DC-DC power module chip is used to isolate the voltage converted by the single-phase rectifier to ensure that when a short-circuit fault occurs in the input voltage of the power management module, it does not affect the operation of other modules in the system. The voltage isolated by the isolated DC-DC power module chip is 5V. A linear voltage regulator is used to convert the 12V voltage into a 3.3V voltage to supply power to the main control module and the data acquisition module in the system. Capacitors C1, C2, C3, C4, C5, and C6 are used to remove the AC interference between the voltage input signal and the voltage output signal of the second common-mode filter, isolated DC-DC power module chip, and linear voltage regulator. Among them, the capacitance values of C1, C3, and C5 are 22 uF, which are used to remove the high-frequency AC interference in the voltage input signal and the voltage output signal, and the capacitance values of C2, C4, and C6 are 0.1 uF, which are used to remove the low-frequency AC interference in the voltage input signal and the voltage output signal.

5. The real-time pressure detection method of a real-time pressure detection system based on advanced physical layer technology according to claim 1, characterized in that It includes the following steps: System power supply: For the APL communication transmission network, the energy signal is extracted based on the APL communication processing module and supplied to the power management module; After the power management module converts the energy signal into the voltages required for the operation of the main control module and the data acquisition module, it supplies power to the main control module and the data acquisition module respectively; Time synchronization: After the APL communication processing module receives the data signal containing the system time from the APL communication transmission network, it extracts the system time and transmits it to the main control module, and the main control module adjusts the local clock according to the received system time; the system time is regularly transmitted to the APL communication transmission network by the monitoring server through data packets; Pressure sensor signal acquisition: The main control module controls the data acquisition module to collect the output signal of the pressure sensor according to the control instruction in the control packet sent by the monitoring server received through the APL communication processing module at the data acquisition frequency in the control instruction; Transmission of the collected data packet: The data acquisition module transmits the collected data to the main control module, the main control module forms a data packet with the collected data and the acquisition time and transmits it to the APL communication processing module, and the APL communication processing module forms the data packet into a data frame and converts it into an APL transmission signal, and sends it to the monitoring server through the APL communication transmission network.

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