CN107659203A - A kind of deep tunnel roof monitoring wireless sensing node based on wind collecting - Google Patents

Abstract

The invention discloses a wireless sensor node for monitoring the roof of a deep roadway based on wind energy collection, which includes a wind energy collector, an intrinsically safe energy collection circuit, a strain sensor module, and a wireless transmission module. The wind energy collector and the intrinsically safe energy collection The circuit is used to convert wind energy into electrical energy, and supply power to the strain sensor module and the wireless transmission module, and the strain sensor module transmits the measured top plate deformation signal to the wireless transmission module, and the wireless transmission module encodes and modulates the signal Process and convert it into a signal suitable for channel transmission, and transmit the signal through the transmitting antenna for the monitoring personnel to receive and analyze. The invention adopts wind energy collection for energy supply, and is an energy collection method with no pollution, simple structure and long service life. The wind energy is used to monitor the wireless sensor nodes on the roof of the deep roadway, so that the wireless sensor nodes can work for a long time, avoiding the inconvenience, waste and environmental pollution caused by battery replacement of traditional wireless sensor nodes.

Description

A wireless sensor node for deep roadway roof monitoring based on wind energy harvesting

technical field

The invention relates to the technical field of wireless sensor nodes, in particular to a wireless sensor node for monitoring the roof of a deep roadway based on wind energy collection.

Background technique

With the continuous increase of coal mine mining depth, the stress change of roadway roof becomes more complicated. In the past ten years, although my country's coal mine disaster accidents have shown a downward trend, there are hundreds of large and small coal mine disaster accidents every year, and coal mine roadway Roof accidents are the main disaster, accounting for half of the total number of accidents in coal mines. Therefore, real-time monitoring of roof stress changes in deep coal mine roadways and judging the stability of roadway roofs have great practical significance for preventing frequent roof accidents. Wireless sensors have the characteristics of small size, low cost, and convenient layout. has been widely applied. Wireless sensor nodes are often widely distributed and work for a long time, but traditional wireless sensor nodes are powered by dry batteries or storage batteries, and the power storage is limited, so the batteries need to be replaced frequently. However, in many application scenarios, it is difficult, sometimes even impossible, to replace batteries for wireless sensor nodes, so traditional power supply methods can no longer meet the energy requirements of wireless sensor nodes. Due to ventilation, there is a large amount of wind energy in the mine. Therefore, in the deep tunnel of the coal mine, wind energy collection technology can be used to convert wind energy into electrical energy to supply power to equipment. Wind energy harvesting technology is a non-polluting, simple structure, and long-life energy harvesting technology. It has a broad application market and can make wireless sensor nodes work for a long time, avoiding the inconvenience, waste and environmental pollution caused by frequent battery replacement.

Contents of the invention

The purpose of the present invention is to provide a wireless sensor node with low cost, long service life and no pollution for deep roadway roof monitoring according to the deficiencies of the prior art.

According to an embodiment of the present invention, a wireless sensor node for monitoring the roof of a deep roadway based on wind energy collection includes a wind energy collector, an intrinsically safe energy harvesting circuit, a strain sensor module, and a wireless transmission module. The energy harvesting circuit is used to convert wind energy into electrical energy, and to supply power to the strain sensor module and the wireless transmission module, and the strain sensor module transmits the measured top plate deformation signal to the wireless transmission module, and the wireless transmission module encodes the signal , Modulation processing, converting into a signal suitable for channel transmission, and transmitting the signal through the transmitting antenna for the monitoring personnel to receive and analyze.

On the basis of the above scheme, the wind energy harvester includes a wind guide window, a resonant cavity, a vibrating beam, a rectifier bridge and a fixed pipe, the wind guide window is connected to the resonant cavity, and the four sides of the resonant cavity have vents , the vibrating beam is composed of a flexible beam and a piezoelectric beam, one end of the vibrating beam is fixed at the end of the vent near the bottom, so that the included angle between the vibrating beam and the resonant cavity is 15 degrees, and the number of the rectifying bridges is Four rectifier bridges are connected to the vibrating beam respectively. The four rectifier bridges are connected in series to the intrinsically safe energy harvesting circuit through wires. The fixed pipe is a cylindrical upper end with a flange fixed, and the lower end is welded on the resonant cavity, which is used to transfer wind energy The collector is fixed on the roadway roof, the intrinsically safe energy harvesting circuit is set on the intrinsically safe energy harvesting circuit board, and the intrinsically safe energy harvesting circuit board is set in the resonant cavity and fixed on the lower bottom of the wind energy harvester superior.

On the basis of the above scheme, the intrinsically safe energy harvesting circuit includes an energy harvester U1, a DC/DC voltage regulator U2, a DC/DC voltage regulator U3, a rectifier bridge U8, an operational amplifier A1, a comparator U4, a comparator U5, comparator U7, NOR gate U6 and FET Q2.

On the basis of the above scheme, the energy harvester U1 integrates a rectifier, a step-down converter and an ultra-low quiescent current undervoltage lockout, and the PZ1 and PZ2 terminals of the energy harvester U1 are connected to the wind energy harvester through a triode Q1 The energy harvester U1 rectifies the unstable voltage generated by the wind energy harvester through a rectifier, and then stores it on the capacitor C1 at the Vin end. When the voltage at the Vin end reaches 4.04V, the Vout end of the energy harvester U1 outputs a stable voltage of 3.6V. voltage value, when the voltage at the Vin terminal drops to 3.77V, the energy harvester U1 turns off the output, and the capacitor C1 charges, and when the voltage on the capacitor C1 reaches 4.04V again, the Vout terminal of the energy harvester U1 has a voltage output, realizing Periodic and intermittent power supply.

On the basis of the above scheme, when the Vout terminal of the energy harvester U1 has a voltage output, the DC/DC voltage regulator U2 and the DC/DC voltage regulator U3 respectively drop the 3.6V voltage to 3.3V and 1.8V, wherein 3.3V The voltage of V is used to power the wireless transmission module and the strain sensor module, and the voltage of 1.8V is connected to the comparator as a reference voltage for overvoltage and overcurrent detection of the circuit.

On the basis of the above scheme, the rectifying bridge U8 and the capacitor C8 form a rectifying and stabilizing circuit to provide voltage for the resistor R8 and the resistor R9, the inverting input terminal of the comparator U7 is connected with the resistors R8 and R9, and the comparator U7 The non-inverting input terminal is connected to the 1.8V voltage, the output terminal of the comparator U7 is connected to the gate of the transistor Q1, the comparator U7, the transistor Q1, the resistor R8 and the resistor R9 form an overvoltage detection circuit, when the voltage generated by the wind energy harvester exceeds 20V , the transistor Q1 will be disconnected.

On the basis of the above scheme, the same input terminal of the comparator U4 is connected with the resistor R4 and the resistor R5, the inverting input terminal of the comparator U4 is connected with the 1.8V voltage, the output terminal is connected with the NOR gate U6, and the comparator U4 Used to detect the size of the output voltage.

On the basis of the above scheme, the same-inverting input terminal of the operational amplifier A1 is connected to the resistor R7, the inverting input terminal of the operational amplifier A1 is connected to the resistor R5 and the resistor R6, and the output terminal of the operational amplifier A1 is connected to the non-inverting input terminal of the comparator U5. The input terminal is connected; the inverting input terminal of the comparator U5 is connected with the 1.8V voltage, the output terminal of the comparator U5 is connected with the NOR gate U6, and the comparator U5 is connected with the operational amplifier A1, the resistor R5, the resistor R6 and the resistor R7 Form the current detection circuit.

On the basis of the above scheme, the drain of the field effect transistor Q2 is connected to the OUT terminal of the DC/DC regulator U2, the gate is connected to the NOR gate U6, the source is connected to the wireless transmission module and the strain sensor, and the field Effect transistor Q2, comparator U4, comparator U5, NOR gate U6 and operational amplifier A1 form an overvoltage and overcurrent protection circuit.

Compared with the prior art, the present invention has the beneficial effects that: the wireless sensing node for deep roadway roof monitoring of the present invention is powered by wind energy collection, which is an energy collection method with no pollution, simple structure and long life. The wind energy is used to monitor the wireless sensor nodes on the roof of the deep roadway, so that the wireless sensor nodes can work for a long time, avoiding the inconvenience, waste and environmental pollution caused by battery replacement of traditional wireless sensor nodes.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is a general design block diagram of a wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting involved in the present invention.

Fig. 2 is the wind energy harvester involved in the present invention.

In the figure: 1-wind guide window, 2-resonant cavity, 3-vent, 4-flexible beam, 5-piezoelectric beam, 6-rectifier bridge, 7-wire, 8-fixed tube, 9-intrinsically safe energy Collect circuit boards.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In describing the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc. indicate an orientation or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as limiting the invention.

Fig. 1 is a wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to the present invention. The wireless sensor node includes: a wind energy harvester, an intrinsically safe energy harvesting circuit, a strain sensor module, and a wireless transmission module. The intrinsically safe energy harvesting circuit includes: energy harvester U1, DC/DC regulator U2, DC/DC regulator U3, rectifier bridge U8, operational amplifier A1, comparator U4, comparator U5, comparator U7, or NOT gate U6 and FET Q2.

Referring to FIG. 2 , the wind energy harvester is composed of a wind guide window 1 , a resonant cavity 2 , a vibrating beam, a rectifier bridge 6 and a fixed pipe 8 . The wind guide window 1 is connected with the resonant cavity 2 together. The wind guide window 1 is similar to a horn, and its air inlet is a round mouth with a diameter of 50mm, and the air outlet is a round mouth with a diameter of 20mm. The resonant cavity 2 is a quadrangular prism with both upper and lower bases, the lengths of the upper, lower and height in the cavity are 30mm, 60mm and 100mm respectively, and the lengths of the upper and lower base and height of the shape are 34mm respectively , 64mm and 104mm.

The four sides of the resonant cavity 2 all have a vent 3 with a length and a width of 50 mm and 8 mm. The vibrating beam is composed of flexible beam 4 and piezoelectric beam 5. The total length of the vibrating beam is 50 mm and the width is 7.6 mm. The piezoelectric beam 5 is 10 mm long and 0.5 mm thick, and the flexible beam 4 is 40 mm long and 0.4 mm thick. One end of the vibrating beam is fixed on the end of the vent 3 close to the lower bottom, so that the included angle between the vibrating beam and the resonant cavity 2 is 15 degrees.

The four rectifier bridges 6 are respectively connected to the vibrating beam, and then the four rectifier bridges 6 are connected in series to the intrinsically safe energy harvesting circuit through wires 7 .

The fixed pipe 8 is cylindrical, with a diameter of 10mm and a length of 60mm. The upper end is fixed with a flange, and the lower end is welded on the resonant cavity 2 for fixing the wind energy harvester on the roadway roof.

The intrinsically safe energy harvesting circuit is arranged on the intrinsically safe energy harvesting circuit board 9, and the intrinsically safe energy harvesting circuit board 9 is arranged in the resonant cavity 2 and fixed on the lower bottom of the wind energy harvester, including: energy harvester U1, DC/DC regulator U2, DC/DC regulator U3, bridge rectifier U8, operational amplifier A1, comparator U4, comparator U5, comparator U7, NOR gate U6 and FET Q2.

The energy harvester U1 integrates a low-loss, full-wave rectifier, a high-efficiency buck converter, and an ultra-low quiescent current undervoltage lockout (UVLO). The PZ1 and PZ2 ends of the energy harvester U1 are connected to the wind energy harvester through a triode Q1. The energy harvester U1 rectifies the unstable voltage generated by the wind energy harvester through the rectifier, and then stores it on the capacitor C1 at the Vin terminal. When the voltage at the Vin terminal reaches 4.04V (the lowest value is 3.77V, and the highest value is 4.30V), the energy The Vout terminal of the collector U1 outputs a regulated voltage value of 3.6V. When the voltage at the Vin terminal drops to 3.77V, the energy collector U1 turns off the output, and the capacitor C1 is charged. When the voltage on the capacitor C1 reaches 4.04V again, the energy The Vout terminal of the collector U1 has a voltage output. Repeatedly, periodic and intermittent power supply can be realized.

The DC/DC regulators U2 and U3 have the characteristics of low power consumption, low dropout and linear adjustment. When the Vout terminal of the energy harvester U1 has a voltage output, the two DC/DC voltage regulators U2 and U3 step down the 3.6V voltage to 3.3V and 1.8V respectively. The voltage of 3.3V is used to supply power to the wireless transmission module and the strain sensor module. The 1.8V voltage is connected to the comparator as a reference voltage for overvoltage and overcurrent detection of the circuit.

The rectifier bridge U8 and the capacitor C8 form a rectification and voltage stabilization circuit to provide voltage for the resistors R8 and R9. The inverting input terminal of the comparator U7 is connected to the resistors R8 and R9, and the non-inverting input terminal of the comparator U7 is connected to the 1.8V voltage. The output terminal of the comparator U7 is connected to the gate of the transistor Q1. The comparator U7, the transistor Q1, the resistor R8 and the resistor R9 form an overvoltage detection circuit. When the voltage generated by the wind energy harvester exceeds 20V, the transistor Q1 will be disconnected.

The same-inverting input terminal of comparator U4 is connected to resistor R4 and resistor R5, the inverting input terminal of comparator U4 is connected to 1.8V voltage, the output terminal is connected to NOR gate U6, and comparator U4 is used to detect the voltage of the output terminal .

The same-inverting input terminal of the operational amplifier A1 is connected to the resistor R7, the inverting input terminal of the operational amplifier A1 is connected to the resistor R5 and the resistor R6, the output terminal of the operational amplifier A1 is connected to the non-inverting input terminal of the comparator U5; the inverting input terminal of the comparator U5 The phase input terminal is connected with 1.8V voltage, the output terminal of comparator U5 is connected with NOR gate U6, comparator U5, operational amplifier A1, resistor R5, resistor R6 and resistor R7 form a current detection circuit.

The drain of the field effect transistor Q2 is connected to the OUT terminal of the DC/DC regulator U2, the gate is connected to the NOR gate U6, the source is connected to the wireless transmission module and the strain sensor, and the field effect transistor Q2 is connected to the comparator U4 and the comparator U4. Device U5, NOR gate U6 and operational amplifier A1 form an overvoltage and overcurrent protection circuit to prevent accidents caused by sparks ignited by overcurrent or overvoltage.

The strain sensor module and the wireless transmission module are shown in Figure 1. The wind energy collector converts wind energy into electrical energy, and then supplies power to the strain sensor module and the wireless transmission module through an intrinsically safe energy harvesting circuit. The strain sensor module transmits the measured deformation signal of the top plate to the wireless transmission module. The wireless transmission module performs encoding, modulation and other processing on the signal, converts it into a signal suitable for channel transmission, and transmits it through the transmitting antenna.

The parts of the present invention that are not described in detail are known technologies of those skilled in the art.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (9)

1. A deep roadway roof monitoring wireless sensor node based on wind energy collection, characterized in that: comprise wind energy harvester, intrinsically safe energy harvesting circuit, strain sensor module, wireless transmission module, described wind energy harvester and intrinsically safe type The energy harvesting circuit is used to convert wind energy into electrical energy, and to supply power to the strain sensor module and the wireless transmission module, and the strain sensor module transmits the measured top plate deformation signal to the wireless transmission module, and the wireless transmission module encodes the signal , Modulation processing, converting into a signal suitable for channel transmission, and transmitting the signal through the transmitting antenna for the monitoring personnel to receive and analyze. 2. A kind of wireless sensor node for monitoring the roof of a deep roadway based on wind energy collection according to claim 1, characterized in that: the wind energy collector includes a wind guide window (1), a resonant cavity (2), a vibrating beam, The rectifier bridge (6) and the fixed pipe (8), the wind guide window (1) is connected with the resonant cavity (2), and the four sides of the resonant cavity (2) have vents (3), the vibration The beam is composed of a flexible beam (4) and a piezoelectric beam (5). One end of the vibrating beam is fixed at the end of the vent (3) close to the lower bottom, so that the angle between the vibrating beam and the resonant cavity (2) is 15 degrees. , the number of the rectifier bridges (6) is four, which are respectively connected to the vibrating beam, and the four rectifier bridges (6) are connected in series to the intrinsically safe energy harvesting circuit through wires (7), and the fixed tube (8) A flange is fixed to the cylindrical upper end, and the lower end is welded on the resonant cavity (2), which is used to fix the wind energy harvester on the roadway roof, and the intrinsically safe energy harvesting circuit is arranged on the intrinsically safe energy harvesting circuit board (9 ), the intrinsically safe energy harvesting circuit board (9) is set in the resonant cavity (2) and fixed on the lower bottom of the wind energy harvester. 3. The wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 1, wherein the intrinsically safe energy harvesting circuit includes an energy harvester U1, a DC/DC voltage regulator U2, DC/DC regulator U3, bridge rectifier U8, operational amplifier A1, comparator U4, comparator U5, comparator U7, NOR gate U6 and FET Q2. 4. A wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 3, characterized in that: the energy harvester U1 integrates a rectifier, a step-down converter and an ultra-low quiescent current undervoltage Blocking, the PZ1 and PZ2 terminals of the energy harvester U1 are connected to the wind energy harvester through a transistor Q1, the energy harvester U1 rectifies the unstable voltage generated by the wind energy harvester through a rectifier, and then stores it on the capacitor C1 at the Vin end, When the voltage at the Vin terminal reaches 4.04V, the Vout terminal of the energy harvester U1 outputs a regulated voltage value of 3.6V. When the voltage at the Vin terminal drops to 3.77V, the energy harvester U1 turns off the output, and the capacitor C1 is charged. When the capacitor C1 When the voltage above reaches 4.04V again, the Vout terminal of the energy harvester U1 has a voltage output to realize periodic and intermittent power supply. 5. A kind of wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 4, characterized in that: when the Vout end of the energy harvester U1 has a voltage output, the DC/DC regulator U2, The DC/DC regulator U3 reduces the 3.6V voltage to 3.3V and 1.8V respectively, of which the 3.3V voltage is used to power the wireless transmission module and the strain sensor module, and the 1.8V voltage is connected to the comparator as a reference voltage , for overvoltage and overcurrent detection of the circuit. 6. The wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 5, characterized in that: said rectifier bridge U8 and capacitor C8 form a rectifier and voltage regulator circuit to provide voltage for resistor R8 and resistor R9 , the inverting input terminal of the comparator U7 is connected with the resistors R8 and R9, the non-inverting input terminal of the comparator U7 is connected with a voltage of 1.8V, the output terminal of the comparator U7 is connected with the gate of the transistor Q1, and the comparator U7 is connected with the transistor Q1 Q1, resistor R8 and resistor R9 form an overvoltage detection circuit. When the voltage generated by the wind energy collector exceeds 20V, the transistor Q1 will be disconnected. 7. A kind of wireless sensing node based on wind energy harvesting for deep roadway roof monitoring according to claim 6, characterized in that: the same direction input terminal of the comparator U4 is connected with the resistor R4 and the resistor R5, and the comparator U4 The inverting input terminal is connected with 1.8V voltage, the output terminal is connected with the NOR gate U6, and the comparator U4 is used to detect the voltage of the output terminal. 8. The wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 7, characterized in that: the same direction input terminal of the op amp A1 is connected to the resistor R7, and the inverting input of the op amp A1 Terminal is connected with resistor R5 and resistor R6, the output terminal of operational amplifier A1 is connected with the noninverting input terminal of comparator U5; the inverting input terminal of described comparator U5 is connected with 1.8V voltage, the output terminal of comparator U5 is connected with or Inverter U6 is connected, and comparator U5 forms a current detection circuit with operational amplifier A1, resistor R5, resistor R6 and resistor R7. 9. A wireless sensor node for monitoring the roof of a deep roadway based on wind energy harvesting according to claim 8, characterized in that: the drain of the field effect transistor Q2 is connected to the OUT end of the DC/DC regulator U2, The gate is connected to the NOR gate U6, the source is connected to the wireless transmission module and the strain sensor, and the field effect transistor Q2, the comparator U4, the comparator U5, the NOR gate U6 and the operational amplifier A1 form an overvoltage and overcurrent protection circuit.