Low power consumption, simple and universal cable manhole cover monitoring device

Abstract

The present invention discloses a low-power simple universal cable manhole cover monitoring device, comprising a travel switch, which is arranged on the inner lower edge of the manhole cover to be monitored, and a manhole cover state monitoring unit is arranged on the travel switch, and the manhole cover state monitoring unit is connected to an MCU control unit, and the MCU control unit is respectively connected to a wireless communication unit, a clock unit, a data storage unit, a battery and a voltage conversion unit, a power supply control unit and a debugging serial port, and the MCU control unit monitors the switch state of the manhole cover in real time through the manhole cover state monitoring unit circuit, and the clock unit is regularly turned on at a preset time interval to supply power to the wireless communication unit module and the data storage unit, and the current manhole cover state is timely reported through the wireless communication unit, and connected to a background monitoring center. The present invention realizes the function of real-time monitoring and timely alarming of the state of the cable manhole cover, and improves the safety protection of the cable manhole cover.

Description

Technical Field

[0001] The invention relates to a cable well cover monitoring device, in particular to a low-power consumption, simple and universal cable well cover monitoring device. Background Art

[0002] With the rapid development of power construction, the number of power cable tunnels and cable trenches is increasing, and the number of cable manhole covers is also increasing. Since the high-voltage cables laid in cable tunnels and cable trenches are the lifeblood of the city, once illegal elements illegally invade and carry out sabotage or theft, it will cause cable operation failure or equipment and facilities to be damaged and stolen, and even cause large-scale power outages, which will cause a huge safety accident. However, most of the manhole covers are ordinary non-intelligent manhole covers, that is, ordinary casting mechanical manhole covers. Therefore, in order to improve the reliability and safety of power transmission, it is necessary to monitor the switch status of these manhole covers in real time, improve security measures, avoid illegal intrusion, and damage to power facilities. In addition, there is generally no external power supply available at the location of the manhole cover, and the monitoring device needs to be powered by a large-capacity battery. Therefore, the design requires a low-power design, and the power consumption of the equipment is reduced by taking some power consumption control methods. However, how to design the monitoring device to have lower power consumption is also a relatively difficult problem to solve. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a low-power, simple and universal cable manhole cover monitoring device which can effectively reduce the power consumption of the monitoring device and increase the battery life.

[0004] The technical solution adopted by the present invention to solve the technical problem is:

[0005] A low-power, simple and universal cable manhole cover monitoring device comprises a travel switch, wherein the travel switch is arranged on the inner lower edge of the manhole cover to be monitored, and a manhole cover status monitoring unit is arranged on the travel switch, and the manhole cover status monitoring unit is connected to an MCU control unit, and the MCU control unit is respectively connected to a wireless communication unit, a clock unit, a data storage unit, a battery and a voltage conversion unit, a power control unit and a debugging serial port, and the MCU control unit monitors the switch status of the manhole cover in real time through the manhole cover status monitoring unit circuit, and an NB-IOT module is arranged on the wireless communication unit, and the clock unit turns on the MCU control unit at a preset time interval. After the MCU control unit is turned on, the NB_POWER signal on the power control unit is set to a high level, so that the transistor Q2 is in a conducting state, thereby driving the P-channel MOS tube MOS1 The wireless communication unit module is turned on, and then the NB_REST on the wireless communication unit is set to a low level for 200ms and then to a high level, so that the NB-IOT module on the wireless communication unit is reset, and a connection with the background monitoring center is established. The data storage unit is powered on through the V33_CTL signal on the power control unit. The manhole cover status monitoring unit detects the manhole cover status and stores the status data in the data storage unit, and reports the current manhole cover status in time through the wireless communication unit, and connects to the background monitoring center.

[0006] The MCU control unit adopts STMicroelectronics' 32-bit ARM processor STM32L151C8T6 as the main control MCU. The chip has 64KB of ROM, 10KB of RAM, and 4KB of EEPROM, and has the characteristics of low power consumption. When the device is working normally, the MCU judges the state change of the travel switch installed under the manhole cover in real time through the manhole cover state monitoring unit circuit. When the manhole cover is opened, the swing arm of the travel switch will automatically pop up, so that the output of the travel switch changes. The device generates an alarm event of the manhole cover state change, and reports the alarm data through the wireless communication unit (carrying the Internet of Things module NB-IOT) to the relevant person in charge of the monitoring center. The person in charge performs further verification and processing. If there is no change in the output state of the travel switch within a certain period of time, the MCU will enter a low-power mode, first cutting off the peripheral circuit and The power supply of the wireless communication unit completely powers off the peripheral devices, and then the MCU configures its own IO port as a non-pull-up analog input, and turns off the IO port clock, serial port clock, and timer clock to achieve low power consumption; the state input pin IN0 of the travel switch is connected to the wake-up pin (PA0-WKUP) of the main control MCU. When the state of the travel switch of the manhole cover status monitoring changes, a level change will occur to wake up the main control MCU, and the program of the device will be restarted. The program control first powers on the peripheral devices and connects to the background monitoring center through the wireless communication unit. If the state of the manhole cover does not change for a period of time, the main control MCU will enter the sleep mode again to achieve a low-power design for system operation; in addition, the device is designed with a timed wake-up function. The device wakes up and runs at a certain time interval, detects the state of the manhole cover once, and reports to the background monitoring center, and then enters the sleep mode again.

[0007] The clock unit is composed of Epson's low-power real-time clock chip RX-8025SA, a backup button battery CR2032, and two reverse-proof Schottky diodes 1N5819. The RX-8025SA has high reliability, stability, and low power consumption, and can meet industrial-grade requirements.

[0008] The travel switch is a long-stroke self-resetting adjustable roller arm travel switch. The wireless communication unit adopts a low-power carrier Internet of Things module NB-I0T. The MCU control unit controls the power-on and connection establishment processes to achieve data communication. The circuit composition of the wireless communication unit is mainly composed of the NB-I0T module and the operation indication circuit of the NB-IOT module, the SIM card circuit, the antenna circuit and the reset control circuit. The SIM card circuit adopts the ESDA6V8AV5 lightning protection and anti-static chip, and supports hot plugging of SIM cards. NB-I0T is an emerging technology in the I0T field, supporting cellular data connection of low-power devices in the wide area network, also known as low-power wide area network (LPWAN). NB-I0T supports efficient connection of devices with long standby time and high network connection requirements, and can also provide very comprehensive indoor cellular data connection coverage.

[0009] The data storage unit uses the ferroelectric memory FM24CL64-G to store data, and the data will not be lost in case of power failure. When the main control MCU is in sleep mode, the data storage unit will be in a power-off state, and the data will not be lost due to power failure. The ferroelectric memory combines the non-volatile data storage characteristics of ROM with the advantages of unlimited read and write, high-speed read and write, and low power consumption of RAM, and is very suitable for the design requirements of manhole cover monitoring devices.

[0010] The manhole cover status monitoring unit is used to detect the state change of the manhole cover, realize voltage isolation through the optical coupler U30 (NEC2701), improve the anti-interference ability of the equipment through the surrounding circuits (capacitors, diodes, TVS tubes), and realize the protection of the MCU.

[0011] The power control unit includes two power control channels, one for controlling the power of the wireless communication module and the other for controlling the power of the data storage unit. This part of the circuit mainly consists of high-power P-channel MOS tubes and control transistors (9014) and other devices. When the MCU is in sleep mode, the control pins NB_POWER and V33_CTL are configured as analog inputs without pull-up, so the MOS tube cannot be driven to supply power, and the power supply of the subsequent circuit is naturally turned off; one of the channels is for power on / off management of the wireless communication module (NB-IOT), as well as the peripheral circuit and the SIM card circuit. The power consumption of the wireless communication module is relatively large in the entire device, so the power is also cut off to reduce power consumption; the other power control channel controls the power of the ferroelectric memory. Similarly, after the MCU is in sleep mode, the power supply of this part of the circuit is also turned off.

[0012] The battery and voltage conversion unit uses a 4.2V / 20000mAh polymer lithium battery with an output current of up to 2A. When powered by the battery, the output voltage of 3.7V-4.2V is converted to 3.3V through the power chip RT8059 to supply the MCU control unit, data storage unit and its peripheral circuits. The power chip RT8059 is a high-efficiency pulse width modulation (PWM) step-down DC / DC converter that can provide 1A output current in a wide input voltage range of 2.8V to 5.5V. The RT8059 is very suitable for portable electronic devices powered by a single lithium-ion battery or by other power sources within a range.

[0013] The debugging serial port adopts the TTL level serial communication mode, which is mainly used to communicate with the MCU to set some parameters, including the wake-up interval, the manhole cover installation address, and the device's own ID number; parameters such as the equipment production date, and can also read parameters and event data.

[0014] The positive beneficial effects of the present invention are:

[0015] 1. The present invention solves the monitoring problem of some common non-intelligent cable tunnel manhole covers. The construction and transformation workload is small, the installation is simple, the transformation cost is low, and there is no need to replace the manhole cover. Only a set of manhole cover monitoring devices needs to be installed.

[0016] 2. The present invention realizes the development of manhole cover monitoring device through a low-power design method, which can timely grasp the status information of the manhole cover, and use the NB-IoT network to send alarm information to the server when the manhole cover is moved or damaged, and notify the management personnel of the monitoring center, thereby avoiding the intrusion of cable manhole covers and the damage and loss of power facilities to the greatest extent.

[0017] 3. The present invention realizes the wireless data transmission function by adopting the new narrowband Internet of Things NB-iot technology. This technology has the advantages of low power consumption, low cost, wide coverage, and support for ultra-large connections. It has greatly improved and optimized the traditional Internet of Things model and perfectly solved the communication problems encountered in the previous manhole cover monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a logical connection diagram of the low-power simple and universal cable manhole cover monitoring device of the present invention;

[0019] Figure 2 yes Figure 1 The circuit schematic diagram of the MCU main control unit;

[0020] Figure 3 yes Figure 1 The circuit schematic diagram of the wireless communication unit;

[0021] Figure 4 yes Figure 1 The circuit schematic diagram of the manhole cover status monitoring unit;

[0022] Figure 5 yes Figure 1 The circuit diagram of the power control unit in the middle;

[0023] Figure 6 yes Figure 1 The circuit schematic diagram of the battery and voltage conversion unit;

[0024] Figure 7 yes Figure 1 The circuit schematic diagram of the data storage unit;

[0025] Figure 8 yes Figure 1 The circuit schematic diagram of the clock unit in the figure;

[0026] Fig. 9 yes Figure 1 Circuit schematic diagram of the debug serial port. DETAILED DESCRIPTION

[0027] The following is combined with Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 The present invention will be further explained and illustrated with specific embodiments:

[0028] Embodiment: A low-power, simple and universal cable manhole cover monitoring device comprises a travel switch, wherein the travel switch is arranged on the inner lower edge of the manhole cover to be monitored, and a manhole cover status monitoring unit is arranged on the travel switch, and the manhole cover status monitoring unit is connected to an MCU control unit, and the MCU control unit is respectively connected to a wireless communication unit, a clock unit, a data storage unit, a battery and a voltage conversion unit, a power control unit and a debugging serial port, and the MCU control unit monitors the switch status of the manhole cover in real time through the manhole cover status monitoring unit circuit, and an NB-IOT module is arranged on the wireless communication unit, and the clock unit turns on the MCU control unit at a preset time interval. After the MCU control unit is turned on, the NB_POWER signal on the power control unit is set to a high level, so that the transistor Q2 is in a conducting state, thereby driving the P-channel MOS tube MOS1 The wireless communication unit module is turned on, and then the NB_REST on the wireless communication unit is set to a low level for 200ms and then to a high level, so that the NB-IOT module on the wireless communication unit is reset, and a connection with the background monitoring center is established. The data storage unit is powered on through the V33_CTL signal on the power control unit. The manhole cover status monitoring unit detects the manhole cover status and stores the status data in the data storage unit, and reports the current manhole cover status in time through the wireless communication unit, and connects to the background monitoring center.

[0029] The MCU control unit adopts STMicroelectronics' 32-bit ARM processor STM32L151C8T6 as the main control MCU. The chip has 64KB of ROM, 10KB of RAM, and 4KB of EEPROM, and has the characteristics of low power consumption. When the device is working normally, the MCU judges the state change of the travel switch installed under the manhole cover in real time through the manhole cover state monitoring unit circuit. When the manhole cover is opened, the swing arm of the travel switch will automatically pop up, so that the output of the travel switch changes. The device generates an alarm event of the manhole cover state change, and reports the alarm data through the wireless communication unit (carrying the Internet of Things module NB-IOT) to the relevant person in charge of the monitoring center. The person in charge performs further verification and processing. If there is no change in the output state of the travel switch within a certain period of time, the MCU will enter a low-power mode, first cutting off the peripheral circuit and The power supply of the wireless communication unit completely powers off the peripheral devices, and then the MCU configures its own IO port as a non-pull-up analog input, and turns off the IO port clock, serial port clock, and timer clock to achieve low power consumption; the state input pin IN0 of the travel switch is connected to the wake-up pin (PA0-WKUP) of the main control MCU. When the state of the travel switch of the manhole cover status monitoring changes, a level change will occur to wake up the main control MCU, and the program of the device will be restarted. The program control first powers on the peripheral devices and connects to the background monitoring center through the wireless communication unit. If the state of the manhole cover does not change for a period of time, the main control MCU will enter the sleep mode again to achieve a low-power design for system operation; in addition, the device is designed with a timed wake-up function. The device wakes up and runs at a certain time interval, detects the state of the manhole cover once, and reports to the background monitoring center, and then enters the sleep mode again.

[0030] The clock unit is composed of Epson's low-power real-time clock chip RX-8025SA, a backup button battery CR2032, and two reverse-proof Schottky diodes 1N5819. The RX-8025SA has high reliability, stability, and low power consumption, and can meet industrial-grade requirements.

[0031] The travel switch is a long-stroke self-resetting adjustable roller arm travel switch. The wireless communication unit adopts a low-power carrier Internet of Things module NB-I0T. The MCU control unit controls the power-on and connection establishment processes to achieve data communication. The circuit composition of the wireless communication unit is mainly composed of the NB-I0T module and the operation indication circuit of the NB-IOT module, the SIM card circuit, the antenna circuit and the reset control circuit. The SIM card circuit adopts the ESDA6V8AV5 lightning protection and anti-static chip, and supports hot plugging of SIM cards. NB-I0T is an emerging technology in the I0T field, supporting cellular data connection of low-power devices in the wide area network, also known as low-power wide area network (LPWAN). NB-I0T supports efficient connection of devices with long standby time and high network connection requirements, and can also provide very comprehensive indoor cellular data connection coverage.

[0032] The data storage unit uses the ferroelectric memory FM24CL64-G to store data, and the data will not be lost in case of power failure. When the main control MCU is in sleep mode, the data storage unit will be in a power-off state, and the data will not be lost due to power failure. The ferroelectric memory combines the non-volatile data storage characteristics of ROM with the advantages of unlimited read and write, high-speed read and write, and low power consumption of RAM, and is very suitable for the design requirements of manhole cover monitoring devices.

[0033] The manhole cover status monitoring unit is used to detect the state change of the manhole cover, realize voltage isolation through the optical coupler U30 (NEC2701), improve the anti-interference ability of the equipment through the surrounding circuits (capacitors, diodes, TVS tubes), and realize the protection of the MCU.

[0034] The power control unit includes two power control channels, one for controlling the power of the wireless communication module and the other for controlling the power of the data storage unit. This part of the circuit mainly consists of high-power P-channel MOS tubes and control transistors (9014) and other devices. When the MCU is in sleep mode, the control pins NB_POWER and V33_CTL are configured as analog inputs without pull-up, so the MOS tube cannot be driven to supply power, and the power supply of the subsequent circuit is naturally turned off; one of the channels is for power on / off management of the wireless communication module (NB-IOT), as well as the peripheral circuit and the SIM card circuit. The power consumption of the wireless communication module is relatively large in the entire device, so the power is also cut off to reduce power consumption; the other power control channel controls the power of the ferroelectric memory. Similarly, after the MCU is in sleep mode, the power supply of this part of the circuit is also turned off.

[0035] The battery and voltage conversion unit uses a 4.2V / 20000mAh polymer lithium battery with an output current of up to 2A. When powered by the battery, the output voltage of 3.7V-4.2V is converted to 3.3V through the power chip RT8059 to supply the MCU control unit, data storage unit and its peripheral circuits. The power chip RT8059 is a high-efficiency pulse width modulation (PWM) step-down DC / DC converter that can provide 1A output current in a wide input voltage range of 2.8V to 5.5V. The RT8059 is very suitable for portable electronic devices powered by a single lithium-ion battery or by other power sources within a range.

[0036] The debugging serial port adopts the TTL level serial communication mode, which is mainly used to communicate with the MCU to set some parameters, including the wake-up interval, the manhole cover installation address, and the device's own ID number; parameters such as the equipment production date, and can also read parameters and event data.

[0037] When working, the present invention normally wakes up the work according to the preset time interval. After the main control MCU is awakened, the system program restarts. First, the wireless communication unit is controlled to be powered on. By setting the pin NB_POWER signal to a high level, the transistor Q2 is in a conducting state, thereby driving the P-channel MOS tube MOS1 to be turned on, and the power provided by the battery supplies power to the NB-IOT module; then the pin NB_REST is set to a low level for 200ms and then to a high level to reset the NB-IOT module and realize the reporting of data and events; the same principle controls the V33_CTL signal to power on the ferroelectric memory U2 (FM24CL64-G), and detects the state of the manhole cover through the manhole cover state monitoring unit and stores the state data in the ferroelectric memory. If the state of the manhole cover changes, the manhole cover event data will be generated and stored in the ferroelectric memory, and the current manhole cover state will be reported in time through the NB-IOT wireless communication module to inform the background monitoring center; when the MCU After a delay of a period of time, it will enter the dormant low-power state again. First, the power supply of the peripheral circuit and the wireless communication module is cut off to completely power off the peripheral devices. Then the main control MCU configures its own IO port as a non-pull-up analog input, and turns off the IO port clock, serial port clock, and timer clock to achieve low power consumption. If the manhole cover is opened when the MCU is in the dormant state, the output state of the travel switch changes. Through the manhole cover status monitoring unit circuit, the optocoupler is turned on to change the IN0 signal from a low level to a high level, thereby achieving the change of the input level. Since the IN0 signal is connected to the wake-up pin of the main control MCU, the MCU is awakened, the program is re-run, and the device generates an alarm event that the manhole cover is opened. The alarm event is reported through the wireless communication NB-IOT module, and the relevant personnel of the background monitoring center are notified to promptly confirm whether the manhole cover is abnormally opened. In addition, the present invention is also designed with a clock chip U3 (RX-8025SA), the reported event will include the time of the event and the preset installation location information of the manhole cover, so that the background monitoring center can quickly determine the abnormality of the event based on the time stamp and location information. In terms of design, in order to ensure the accuracy of the clock, the background master station is required to include the time stamp of the current time of the background server in the response message. The device will calibrate its own clock according to the time stamp to keep it consistent with the server clock.

[0038] The above description is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A low-power, simple and universal cable manhole cover monitoring device, including a travel switch, characterized in that: The travel switch is arranged on the inner lower wall of the manhole cover to be monitored, and a manhole cover status monitoring unit is arranged on the travel switch, and the manhole cover status monitoring unit is connected to the MCU control unit, and the MCU control unit is respectively connected to the wireless communication unit, the clock unit, the data storage unit, the battery and the voltage conversion unit, the power control unit and the debugging serial port, and the MCU control unit monitors the switch status of the manhole cover in real time through the manhole cover status monitoring unit circuit, and a NB-IOT module is arranged on the wireless communication unit, and the clock unit turns on the MCU control unit at a preset time interval. After the MCU control unit is turned on, the NB_POWER signal on the power control unit is set to a high level, so that the transistor Q2 is in a conducting state, thereby driving the P-channel MOS tube MOS1 The wireless communication unit module is turned on, and then the NB_REST on the wireless communication unit is set to a low level for 200ms and then set to a high level to reset the NB-IOT module on the wireless communication unit, establish a connection with the background monitoring center, and power on the data storage unit through the V33_CTL signal on the power control unit. The manhole cover status monitoring unit detects the manhole cover status and stores the status data in the data storage unit, and reports the current manhole cover status in time through the wireless communication unit, and connects to the background monitoring center; The MCU control unit adopts STMicroelectronics ST's 32-bit ARM processor STM32L151C8T6 as the main control MCU. The PA0-WKUP pin on the main control MCU is connected to the travel switch state input pin IN0 on the manhole cover status monitoring unit. When the travel switch state monitored by the manhole cover status monitoring unit changes, a level change will occur, the MCU will be started and powered on, and connected to the background monitoring center through the wireless communication unit. If the manhole cover state does not change for a period of time, the main control MCU will enter sleep mode; The travel switch is a long-stroke self-resetting adjustable roller arm travel switch. The wireless communication unit adopts a low-power carrier Internet of Things module NB-I0T. The MCU control unit controls the power-on and connection establishment processes to achieve data communication. The circuit composition of the wireless communication unit consists of an NB-I0T module and an operation indication circuit of the NB-IOT module, a SIM card circuit, an antenna circuit and a reset control circuit. The SIM card circuit adopts an ESDA6V8AV5 lightning protection and anti-static chip to support hot plugging of SIM cards.

2. The low-power, simple and universal cable manhole cover monitoring device according to claim 1 is characterized in that: The data storage unit uses a ferroelectric memory FM24CL64-G to store data, and the power control unit includes two power supply controls, one for controlling the power supply of the wireless communication unit and the other for controlling the power supply of the data storage unit; the battery in the battery and voltage conversion unit uses a 4.2V / 20000mAh polymer lithium battery, and the output current can reach 2A. When the battery is powered, the output voltage of 3.7V-4.2V is converted to 3.3V through the power chip RT8059 to supply the MCU control unit, the data storage unit and its peripheral circuits.

Images