Battery-free solar direct-driven wireless sensing terminal and control method

Abstract

The invention discloses a battery-free solar direct-driven wireless sensing terminal and a control method, and the terminal comprises a solar panel which is used for converting light energy into direct-current electric energy; the conversion circuit is used for dynamically adjusting input impedance; the super capacitor bank receives the electric energy converted by the conversion circuit for charging; the illumination sensing circuit is used for monitoring the ambient light intensity in real time, and sending a signal to the dynamic load control circuit when the illumination intensity is greater than the preset illumination intensity; the voltage monitoring circuit is used for continuously detecting the voltage state of the super capacitor bank, and when the voltage is greater than a preset voltage, the comparator directly triggers the MCU to interrupt; the dynamic load control circuit is used for supplying power to a radio frequency part power supply when the requirement is met and cutting off a load when the requirement is not met; and the wireless communication module is used for uploading the compressed data to a cloud. According to the invention, zero battery maintenance cost is realized, the extreme environment adaptability is enhanced, and the system reliability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Internet of Things terminals, and particularly to a battery-free solar direct-drive wireless sensing terminal and a control method. BACKGROUND

[0002] Traditional outdoor sensors rely on lithium battery power supply, using a solar battery + storage battery solution, but lithium battery power supply has defects, such as rapid battery life decay in low or high temperature environments, and even cannot work, the storage battery life accelerates decay at high temperature, and the lithium battery capacity drops sharply at low temperature, such as extreme environments such as deserts and snow mountains, low light conditions such as overcast, haze, and high latitude winter, solar panel efficiency decreases significantly, which may cause system paralysis, and insufficient energy storage in overcast weather may also cause data loss. In addition, lithium battery power supply also has high battery replacement cost, increases the risk of environmental pollution, and the current peak of the module start-up moment can cause the solar direct power supply system to collapse.

[0003] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0004] The main purpose of the present application is to provide a battery-free solar direct-drive wireless sensing terminal and a control method, aiming to solve the problems of poor environmental adaptability, high cost, and easy to cause system collapse of lithium battery power supply in the prior art.

[0005] To achieve the above purpose, the present application provides a battery-free solar direct-drive wireless sensing terminal, which comprises:

[0006] A solar panel is used to convert light energy into direct current power and send it to a conversion circuit;

[0007] The conversion circuit is used to dynamically adjust the input impedance, so that the solar panel outputs power with the highest efficiency, and stabilizes the voltage to the working range of the super capacitor group;

[0008] The super capacitor group receives the converted power of the conversion circuit for charging and provides a short-time large current discharge function;

[0009] An illumination sensing circuit is used to monitor the ambient light intensity in real time, and when the light intensity is greater than the preset light intensity, a signal is sent to the dynamic load control circuit;

[0010] A voltage monitoring circuit is used to continuously detect the voltage state of the super capacitor group, and when the voltage is greater than the preset voltage, the comparator directly triggers the MCU interrupt;

[0011] Dynamic load control circuit, for turning on when the capacitance and voltage meet the requirements, or the light intensity meets the requirements of maintaining the system operation, and supplying power to the radio frequency part, and cutting off the load when the capacitance and voltage do not meet the requirements or the light intensity does not meet the requirements.

[0012] Wireless communication module, including MCU power supply and radio frequency power supply, for working when the power supply is turned on, adopting compact sequential compressed data, and uploading data to the cloud, and immediately after the communication is completed, only the MCU power supply is reserved.

[0013] Optionally, the battery-free solar direct-drive wireless sensing terminal, wherein the conversion circuit adopts a maximum power point tracking technology to dynamically adjust the input impedance.

[0014] Optionally, the battery-free solar direct-drive wireless sensing terminal, wherein the battery-free solar direct-drive wireless sensing terminal further comprises:

[0015] Sensor array, for collecting environmental data.

[0016] In addition, to achieve the above-mentioned purpose, the application also provides a control method based on a battery-free solar direct-drive wireless sensing terminal, which comprises the following steps:

[0017] After the battery-free solar direct-drive wireless sensing terminal is powered on and started, the hardware is initialized, the sensor array is activated, the network credentials are set and stored;

[0018] It is judged whether the sensor array is triggered, if yes, data collection is started, and the collected data is compressed and stored in the non-volatile memory;

[0019] The voltage state of the super capacitor group is detected, and it is judged whether the voltage is greater than the preset voltage, if yes, the radio frequency power supply is turned on to connect the network, and the data stored in the non-volatile memory is sent to the server;

[0020] After receiving the confirmation signal of the server, the radio frequency power supply is turned off, and the deep sleep state is entered.

[0021] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the judgment of whether the sensor array is triggered further comprises:

[0022] If the sensor array is not triggered, the battery-free solar direct-drive wireless sensing terminal enters the deep sleep state.

[0023] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the judgment of whether the voltage is greater than the preset voltage further comprises:

[0024] If the voltage is not greater than the preset voltage, the battery-free solar direct-drive wireless sensing terminal enters a deep sleep state.

[0025] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the preset voltage is 3V.

[0026] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the opening of the radio frequency power supply connection network further includes:

[0027] determining whether the wireless access point is successfully connected;

[0028] If yes, jump to data transmission.

[0029] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the determination of whether the wireless access point is successfully connected further includes:

[0030] If the connection of the wireless access point fails, the retry count is incremented by 1, and the number of retries is checked.

[0031] If the number of retries is less than the preset number, the WiFi power is restarted and reconnected.

[0032] If the number of retries is greater than or equal to the preset number, forced sleep.

[0033] Optionally, the control method based on the battery-free solar direct-drive wireless sensing terminal, wherein the preset number is 3.

[0034] In this invention, the battery-free solar-powered direct-drive wireless sensing terminal includes: a solar panel for converting light energy into DC power and sending it to a conversion circuit; a conversion circuit for dynamically adjusting the input impedance so that the solar panel outputs power with maximum efficiency and stabilizes the voltage within the operating range of the supercapacitor bank; a supercapacitor bank for receiving the converted power from the conversion circuit for charging and providing a short-term high-current discharge function; a light intensity sensing circuit for real-time monitoring of ambient light intensity, sending a signal to a dynamic load control circuit when the light intensity is greater than a preset light intensity; a voltage monitoring circuit for continuously detecting the voltage status of the supercapacitor bank, directly triggering an MCU interrupt when the voltage is greater than a preset voltage; a dynamic load control circuit for turning on when the capacitor and voltage meet the requirements, or when the light intensity meets the requirements for maintaining system operation, supplying power to the RF section, and cutting off the load when the capacitor and voltage or the light intensity does not meet the requirements; and a wireless communication module, including an MCU power supply and an RF power supply, for operating when power is on, using compact sequential data compression, and uploading the data to the cloud, and immediately retaining only the MCU power supply after communication is completed. This invention achieves zero battery maintenance costs, enhances adaptability to extreme environments, and improves system reliability. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a preferred embodiment of the battery-free solar-powered direct-drive wireless sensing terminal of the present invention.

[0036] Figure 2 This is a flowchart of a preferred embodiment of the control method of the present invention based on a battery-free solar-powered direct-drive wireless sensing terminal;

[0037] Figure 3 This is a flowchart illustrating the entire control process in a preferred embodiment of the control method for a battery-free solar-powered direct-drive wireless sensing terminal according to the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0039] The battery-free solar-powered direct-drive wireless sensing terminal described in the preferred embodiment of the present invention, such as... Figure 1 As shown, the battery-free solar-powered direct-drive wireless sensing terminal includes:

[0040] Solar panels are used to convert solar energy into direct current (DC) electricity and send it to the conversion circuit.

[0041] Conversion circuit, for dynamically adjusting input impedance, so that the solar panel outputs power with the highest efficiency, and stabilizes the voltage to the working range of the super capacitor group;

[0042] The super capacitor group receives the converted power of the conversion circuit for charging, and provides a short-time large-current discharging function;

[0043] The light sensing circuit is used for monitoring the ambient light intensity in real time, and sends a signal to the dynamic load control circuit when the light intensity is greater than the preset light intensity;

[0044] The voltage monitoring circuit is used for continuously detecting the voltage state of the super capacitor group, and the comparator directly triggers the MCU interrupt when the voltage is greater than the preset voltage;

[0045] The dynamic load control circuit is used for turning on when the capacitance and voltage meet the requirements, or the light intensity meets the requirements for maintaining the system operation, and supplying power to the radio frequency part, and cutting off the load when the capacitance and voltage do not meet the requirements or the light intensity does not meet the requirements;

[0046] The wireless communication module includes an MCU power supply and a radio frequency power supply, and is used for working when the power supply is turned on, adopting compact sequential compressed data, and uploading the data to the cloud, and immediately retaining only the MCU power supply when the communication is completed.

[0047] The solar panel converts light energy into direct current (unstable output, affected by light intensity).

[0048] The conversion circuit is specifically an MPPT DC / DC conversion circuit, which adopts a maximum power point tracking technology, dynamically adjusts the input impedance, ensures that the solar panel always outputs power with the highest efficiency (improves 20-30% energy efficiency), and stabilizes the voltage to the working range of the super capacitor group.

[0049] The super capacitor group (2.7V / 100F*2): in series to form a 5.4V / 50F energy storage unit (or in parallel to form 2.7V / 200F), receives the converted power of the MPPT DC / DC conversion circuit for fast charging (millisecond-level response), and provides a short-time large-current discharging capability (better than a lithium battery).

[0050] The application realizes complete removal of chemical batteries, and realizes energy autonomy through real-time solar power supply + super capacitor transient compensation.

[0051] The light sensing circuit monitors the ambient light intensity in real time, and sends a signal to the dynamic load control circuit when the light intensity is greater than 20000lux, and only starts the radio frequency power supply for data transmission when the light intensity is greater than 20000lux.

[0052] Among them, the voltage monitoring circuit continuously detects the super capacitor voltage state, when the voltage (i.e. super capacitor voltage) > 3.0V, the comparator directly triggers the MCU interrupt (response time < 100ns), and the software polling delay is saved.

[0053] Among them, the MCU controller can also be set: ultra-low power design (running power < 100uA).

[0054] Among them, the dynamic load control circuit: controlled by the GPIO signal of the MCU (high / low level), when the capacitor voltage is sufficient, it is turned on or the light intensity is sufficient to maintain the system work, and the power supply of the radio frequency part is supplied, and when the voltage is insufficient or the light intensity is insufficient, the load is cut off, preventing the system from collapsing.

[0055] The battery-free solar direct-drive wireless sensing terminal also includes a sensor array for collecting environmental data (such as temperature and humidity data).

[0056] Among them, the ultra-low power fast start wireless communication module (WiFi / BLE / NB-IoT module) can be realized, which only works when the power supply is turned on, and uses compact sequential compressed data (single data < 10 bytes), sensor data + system status is packaged and uploaded to the cloud, NB-IoT ensures long-distance low-power communication, and the module radio frequency power is cut off immediately after communication is completed only to keep the MCU part power; cold start time: 30ms, fast start saves power; peak transmit current: 31mA, saves power, and can work normally under low power; wide operating voltage range: 1.7-3.3V, suitable for low voltage operation; wireless communication module SOC with MCU function, radio frequency power domain can be controlled separately.

[0057] Network credentials are pre-stored (network credentials: networked information, such as SSID and password for wifi, and account and password for server login), and data packets are pre-packaged FRAM (i.e. compressing the data to be uploaded and storing it directly into FRAM, which can be used directly next time), data is collected and saved without sending when the voltage < 3.0V, ensuring that the data at night or on cloudy days can be effective. When the voltage > 3.0V, skip the initialization process and directly read the data packet from FRAM to send, saving time and power consumption.

[0058] Further, the control method based on the battery-free solar direct-drive wireless sensing terminal according to the preferred embodiment of the present application, as shown in Figure 2 and Figure 3 The control method based on the battery-free solar direct-drive wireless sensing terminal includes the following steps:

[0059] Step S10, when the battery-free solar direct-drive wireless sensing terminal is powered on, initialize the hardware, activate the sensor array, set the network credentials and store.

[0060] Step S20, determine whether the sensor array is triggered, if yes, start data collection, compress the collected data and store it in the non-volatile memory;

[0061] If the sensor array is not triggered, the battery-free solar direct-drive wireless sensing terminal enters a deep sleep state.

[0062] Step S30, detect the voltage state of the supercapacitor group, determine whether the voltage is greater than the preset voltage, if yes, turn on the radio frequency power to connect the network, and send the data stored in the non-volatile memory to the server;

[0063] If the voltage is not greater than the preset voltage (the preset voltage is 3V), the battery-free solar direct-drive wireless sensing terminal enters a deep sleep state.

[0064] After turning on the radio frequency power to connect the network, it includes: determining whether the wireless access point is successfully connected; if yes, jump to data sending. If the wireless access point connection fails, retry count +1, check the retry count; if the retry count is less than the preset count (the preset count is 3 times), restart the WiFi power and reconnect; if the retry count is greater than or equal to the preset count, force sleep.

[0065] Step S40, when receiving the confirmation signal of the server, turn off the radio frequency power, and enter a deep sleep state.

[0066] As shown in Figure 3 The whole control method includes the following steps:

[0067] Step S100, start;

[0068] Step S101, power on the device, initialize the hardware;

[0069] Step S102, wake up / activate the sensor (such as temperature and humidity / light sensor), collect environmental data;

[0070] Step S103, set the network credentials and store: set the networking information in advance and store it, so that when the data sending condition is met, the data can be quickly sent;

[0071] Step S104, determine whether the sensor (sensor array) is triggered, if the sensor is not triggered, execute step S111;

[0072] Step S105, if the sensor is triggered, start data collection;

[0073] Step S106, data packet pre-packaging and storage to FRAM: compress the original data to 10 bytes to reduce transmission load; store the status of successful transmission into the non-volatile memory (next time the progress can be recovered when waking up);

[0074] Step S107, judge whether the hardware trigger super capacitor voltage is greater than 3.0V; if not greater than 3.0V, execute step S111, continue to wait for sensor trigger (ensure that the capacitor has enough energy to drive subsequent operation);

[0075] Step S108, if not greater than 3.0V, turn on the radio frequency part power supply connection network, adjust the stored network certificate, quickly connect the network, start the data sending process, the sensor trigger voltage is sufficient to trigger the sending process, and ensure that the data can be as timely as possible;

[0076] Connect the wireless access point:

[0077] Success: jump to data sending;

[0078] Failure: retry count + 1, check the number of retries:

[0079] <3 times: restart the WiFi power and reconnect (avoid hardware lock);

[0080] ≥ 3 times: forced hibernation (give up this transmission);

[0081] Step S109, send data packet: send the compressed data in FRAM to the server;

[0082] Step S110, receive ACK, turn off the radio frequency part power, that is, wait for the server confirmation signal (ensure that the data is sent), and immediately power off after receiving the ACK (save energy, the WiFi module has the highest power consumption);

[0083] Step S111, all operations are completed, enter 5 mu A ultra-low power consumption mode, and wait for next wake-up (light / timer trigger).

[0084] In the application, the energy trend is predicted based on light intensity, and the load state is adjusted in advance (such as actively turning off the communication module when the light weakens); only the MCU maintains the hibernation state (power consumption <1 mu A) during standby, and other circuits are completely powered off; the Internet of Things environment monitoring node can work continuously for more than 5 years without battery under intermittent light; the system automatically enters the ultra-low power consumption monitoring mode (only MCU+sensor runs) on cloudy days, and restores full function operation and uploads historical data on sunny days.

[0085] Key points of the application:

[0086] (1) Energy closed-loop management: rely on light and capacitor voltage hardware trigger, ensure that energy is sufficient to start high-power operation; and when the energy is sufficient, send data in time.

[0087] (2) Power consumption optimization: data compression reduces the working time of sending data. The radio frequency power supply (the largest energy consumption module) is turned off immediately after the operation is completed. The deep sleep mode only maintains 5 muA current.

[0088] (3) State persistence: save the state with FRAM, and do not lose the progress in case of power failure.

[0089] The beneficial effects of the present application are:

[0090] (1) Zero battery maintenance cost: compared with the traditional scheme, the maintenance period is extended from 6 months to > 10 years.

[0091] (2) Extreme environment adaptability: the working temperature range is expanded to -40℃~85℃ (without battery limitation).

[0092] (3) System reliability improvement: super capacitor cycle life > 500,000 times (much higher than 2000 times of lithium battery).

[0093] In summary, the present application provides a battery-free solar direct-drive wireless sensing terminal and control method, the battery-free solar direct-drive wireless sensing terminal comprises: a solar panel for converting light energy into direct current and sending to a conversion circuit; a conversion circuit for dynamically adjusting the input impedance, so that the solar panel outputs power with the highest efficiency, and stabilizes the voltage to the working range of the super capacitor group; a super capacitor group receiving the converted power of the conversion circuit for charging and providing a short-time large-current discharge function; a light sensing circuit for real-time monitoring of ambient light intensity, and sending a signal to the dynamic load control circuit when the light intensity is greater than the preset light intensity; a voltage monitoring circuit for continuously detecting the voltage state of the super capacitor group, and the comparator directly triggers the MCU interrupt when the voltage is greater than the preset voltage; a dynamic load control circuit for turning on when the capacitor and voltage meet the requirements, or the light intensity meets the requirements of maintaining system operation, and supplying power to the radio frequency part, and cutting off the load when the capacitor and voltage do not meet the requirements or the light intensity does not meet the requirements; a wireless communication module including an MCU power supply and a radio frequency power supply, for working when the power supply is turned on, adopting compact sequential compressed data, and uploading data to the cloud, and immediately retaining only the MCU power supply after the communication is completed. The present application realizes zero battery maintenance cost, enhances extreme environment adaptability, and improves system reliability.

[0094] It should be noted that, in the present document, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0095] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing relevant hardware (such as a processor, a controller, etc.) through a computer program. The program can be stored in a computer readable computer readable storage medium, and the program can include the processes of the above-mentioned method embodiments when executed. The computer readable storage medium can be a memory, a magnetic disc, an optical disc, etc.

[0096] It should be understood that the application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall fall within the protection scope of the claims of the present application.

Claims

1. A battery-free, solar-powered, direct-drive wireless sensing terminal, characterized in that: The battery-free solar-powered direct-drive wireless sensing terminal includes: Solar panels are used to convert solar energy into direct current (DC) electrical energy and send it to the conversion circuit. The conversion circuit is used to dynamically adjust the input impedance so that the solar panel can output electrical energy with the highest efficiency and stabilize the voltage to the operating range of the supercapacitor bank. The supercapacitor bank receives electrical energy converted by the conversion circuit for charging and provides short-time high-current discharge function. The light sensing circuit is used to monitor the ambient light intensity in real time. When the light intensity is greater than the preset light intensity, it sends a signal to the dynamic load control circuit. The voltage monitoring circuit is used to continuously monitor the voltage status of the supercapacitor bank. When the voltage exceeds the preset voltage, the comparator directly triggers an MCU interrupt. The dynamic load control circuit is used to turn on when the capacitor and voltage meet the requirements, or when the light intensity meets the requirements to maintain the operation of the system, to supply power to the radio frequency section, and to cut off the load when the capacitor and voltage do not meet the requirements or the light intensity does not meet the requirements. The wireless communication module includes an MCU power supply and an RF power supply. It operates when the power is on, uses compact sequential data compression, and uploads the data to the cloud. Once communication is complete, the RF power supply immediately retains only the MCU power supply.

2. The battery-free solar-powered direct-drive wireless sensing terminal according to claim 1, characterized in that, The conversion circuit uses maximum power point tracking technology to dynamically adjust the input impedance.

3. The battery-free solar-powered direct-drive wireless sensing terminal according to claim 1, characterized in that, The battery-free solar-powered direct-drive wireless sensing terminal also includes: Sensor arrays are used to collect environmental data.

4. A control method for a battery-free solar-powered direct-drive wireless sensing terminal based on any one of claims 1-3, characterized in that, The control method based on the battery-free solar-powered direct-drive wireless sensing terminal includes: When the battery-free solar-powered direct-drive wireless sensing terminal is powered on and started, it initializes the hardware, activates the sensor array, sets and stores the network credentials. Determine if the sensor array has been triggered. If so, start data acquisition, compress the acquired data, and store it in non-volatile memory. Detect the voltage status of the supercapacitor bank and determine if the voltage is greater than the preset voltage. If so, turn on the radio frequency power supply to connect to the network and send the data stored in the non-volatile memory to the server. Upon receiving confirmation from the server, the radio frequency power is turned off and the system enters deep sleep mode.

5. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 4, characterized in that, The step of determining whether the sensor array has been triggered also includes: If the sensor array is not triggered, the battery-free solar-powered direct-drive wireless sensing terminal enters a deep sleep state.

6. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 4, characterized in that, The step of determining whether the voltage is greater than a preset voltage further includes: If the voltage is not greater than the preset voltage, the battery-free solar-powered direct-drive wireless sensing terminal enters a deep sleep state.

7. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 6, characterized in that, The preset voltage is 3V.

8. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 4, characterized in that, The step of activating the radio frequency power connection to the network then includes: Determine if the connection to the wireless access point was successful; If so, proceed to data transmission.

9. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 4, characterized in that, The process of determining whether a connection to the wireless access point has been successfully established also includes: If the connection to the wireless access point fails, increment the retry count by 1 and check the number of retries. If the number of retries is less than the preset number, turn the WiFi power back on and reconnect. If the number of retries is greater than or equal to the preset number, force a sleep.

10. The control method for a battery-free solar-powered direct-drive wireless sensing terminal according to claim 9, characterized in that, The preset number of times is 3.

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