System for collecting signals of MSS

Abstract

The invention relates to the technical field of signal collection systems, in particular to an MSS signal collection system which comprises a main control board, a PC upper computer, a signal processing board, an MSS sensor daughter board, a micro pump board and an electromagnetic valve, the PC upper computer is in communication connection with the main control board through a USB serial port, a micro pump is integrated on the micro pump board, and the electromagnetic valve is connected with the signal processing board. The electromagnetic valve is communicated with the micro pump; compared with a mode that an official development board controls background gas and gas to be detected through two micro pumps, one micro pump is matched with the electromagnetic valve to switch the background gas and the gas to be detected, so that the cost is saved, the two gases are ensured to enter through the same pump, and the detection error is not increased due to the difference of the pumps.

Description

Technical Field

[0001] The present invention relates to the technical field of signal collection systems, and in particular to a system for collecting signals from MSSs. Background Art

[0002] MSS, or membrane surface stress sensor, is a new type of sensor element. When the target gas molecules diffuse and contact the sensitive membrane surface of MSS, some of the gas will be adsorbed on the surface of the membrane. Different gases have different adsorption affinities with the membrane surface. Once the gas is adsorbed, the molecular distribution state on the surface of the film will change, causing stress in the film, which in turn causes the film to produce a small deformation to achieve detection. Its unique structure makes it an ideal sensor element, covering all the characteristics required by olfactory sensors.

[0003] MSS is rarely used in the domestic market. Apart from the official development board of MSS, there are few similar devices. The official MSS board in the existing technology is expensive. Two micro pumps are required, which has high production costs. In addition, the two gases enter through different pumps, and the difference in the pumps will increase the detection error. When the micro pump fails, an electrical signal will also be collected, which is similar to low-flow air and cannot be distinguished. Summary of the invention

[0004] The object of the present invention is to provide a system for collecting signals from an MSS to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a system for collecting signals from MSS, comprising a main control board, a PC host computer, a signal processing board, an MSS sensor sub-board, a micro-pump board and a solenoid valve, wherein the PC host computer and the main control board are connected via a USB serial port communication, a micro-pump is integrated on the micro-pump board, the solenoid valve is connected to the micro-pump, and the solenoid valve can be used to select and switch the micro-pump to be connected to the gas to be measured, or the micro-pump to be connected to the air; the micro-pump outputs gas to the MSS sensor sub-board, the MSS sensor sub-board outputs the original signal to the signal processing board, after the signal processing board processes the original signal, the processed signal is input into the main control board, the main control board transmits the data back to the PC host computer via the USB serial port, and the main control board controls the solenoid valve.

[0006] The main control board is integrated with a controllable I / O and a pump drive circuit. The controllable I / O is used to access external devices, and the external devices include a fan module, a temperature control module and an automatic gas distribution device. The main control board is connected to the solenoid valve through the controllable I / O; the pump drive circuit is used to control the micro pump.

[0007] The micro pump board is provided with a three-axis sensor, through which the vibration frequency of the micro pump is monitored to determine the working state of the micro pump, and the three-axis sensor is data-connected with the main control board.

[0008] The MSS sensor sub-board is integrated with an MSS chip substrate and a temperature and humidity sensor. The MSS chip substrate is used to respond to signals of the gas entering the MSS sensor sub-board, and the temperature and humidity sensor is used to monitor temperature and humidity values.

[0009] The main control board is provided with a voltage acquisition system; the signal processing board is provided with a multi-stage filtering module and a signal amplification module. The original signal transmitted by the MSS sensor sub-board is subjected to multi-stage filtering and signal amplification in turn by the multi-stage filtering module and the signal amplification module, and then the signal is output to the voltage acquisition system of the main control board.

[0010] The voltage acquisition system is provided with an adjustable resistor and a voltage conversion chip. The signal acquisition range is adjusted by the adjustable resistor to improve the accuracy. The voltage conversion chip enables circuits with different power supply voltages in the system to communicate with each other.

[0011] The solenoid valve includes a valve body, a switching chamber and a monitoring side chamber, the switching chamber and the monitoring side chamber are opened inside the valve body, there are two groups of monitoring side chambers, and they are respectively connected at the two end positions of the switching chamber, an air outlet interface and an air inlet interface are fixedly set on the surface of the valve body, the air outlet interface is connected with the switching chamber, and there are two groups of air inlet interfaces, and they are respectively connected with the monitoring side chambers; a closed groove is opened on the inner wall surface of the monitoring side chamber, the closed groove is connected with the air inlet interface, a sealing one-way disk is arranged in the closed groove, and the closed groove is in air-tight contact with the sealing one-way disk, an air pressure monitoring probe is embedded on the surface of the valve body, a pressure passage is opened inside the valve body, and the air pressure monitoring probe is connected with the monitoring side chamber through the pressure passage.

[0012] A switching sleeve is arranged in the switching chamber, and the switching sleeve is in the shape of a short cylindrical tube. A rubber sleeve is arranged on the outer surface of the switching sleeve, and the switching sleeve is in airtight contact with the inner wall surface of the switching chamber through the rubber sleeve. Annular side eaves are symmetrically arranged at both ends of the switching sleeve, and a dynamic pressure plate is arranged inside the switching sleeve.

[0013] Centering springs are symmetrically arranged on both sides of the dynamic pressure plate, and the centering springs are compressed and arranged between the dynamic pressure plate and the annular side eaves. Through the elastic force of the centering springs, the dynamic pressure plate is in the middle position of the switching sleeve without being affected by external forces. A corrugated air seal sleeve is connected between the dynamic pressure plate and the annular side eaves. The corrugated air seal sleeve has a gas sealing function and can be axially retracted. A valve stem is fixedly arranged on the switching sleeve, and an electromagnetic actuator is fixedly arranged on the outside of the valve body. The valve stem is inserted and extended to the outside of the valve body and is transmission-connected to the electromagnetic actuator. The valve stem can be driven to axially retract and move through the electromagnetic actuator, and the valve stem is in air-tight contact with the valve body.

[0014] A positioning pressure shaft is fixedly provided on the sealing one-way disc, a spring blind cavity is opened on the inner wall surface of the monitoring side cavity, the positioning pressure shaft is inserted in the spring blind cavity, a pressure spring is arranged inside the spring blind cavity, and the pressure spring applies an axial elastic thrust to the sealing one-way disc through the positioning pressure shaft, so that the sealing one-way disc has an elastic tendency to move toward the closed groove.

[0015] Compared with the prior art, the present invention has the following beneficial effects: Compared with the official development board which controls the background gas and the gas to be tested by two micro pumps, the system for collecting signals from MSS of the present invention uses a micro pump and a solenoid valve to switch the background gas and the gas to be tested, which not only saves costs but also ensures that both gases are pumped in by the same pump, and the detection error will not be increased due to the difference in the pumps.

[0016] In addition, by setting up a three-axis sensor, the fixed vibration frequency of the micropump can be used to monitor whether the micropump is working normally. If no vibration of the micropump is detected after starting the micropump, it means that there is a fault in the circuit, connecting wire or pump itself of the micropump, and this situation can be distinguished well.

[0017] The present invention can control the voltage and frequency of the micro pump through a PC host computer to match different gas flow rates, which is more flexible to use, and can be connected to and matched with external automatic gas distribution equipment through controllable I / O to achieve automatic testing for different gases.

[0018] The solenoid valve in the present invention is designed for the signal collection system and can detect the action of the switching sleeve. When the switching sleeve fails to operate due to a fault in the solenoid valve, it can realize self-detection and provide feedback to the main control board to avoid the problem of incomplete switching of the detection gas and the occurrence of an error in the detection gas object. Moreover, through the structural setting, after the switching sleeve operates, one side of the switching sleeve can always be kept in a positive pressure state, and the sealing between the rubber sleeve and the switching chamber can be continuously monitored to avoid the risk of background gas and test gas mixing in the test data due to wear of the rubber sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the system modules for collecting signals from MSS according to the present invention.

[0020] Figure 2 Schematic diagram of the solenoid valve of the present invention.

[0021] Figure 3 It is a three-dimensional half-section schematic diagram of the solenoid valve of the present invention.

[0022] Figure 4 for Figure 3 A magnified schematic diagram of area A in the middle.

[0023] Figure 5 It is a three-dimensional half-section top view of the solenoid valve of the present invention.

[0024] In the figure: 1. valve body; 2. switching chamber; 3. monitoring side chamber; 4. air outlet interface; 5. air inlet interface; 6. closed groove; 7. sealing one-way disk; 8. air pressure monitoring probe; 9. pressure passage; 201. switching sleeve; 202. rubber sleeve; 203. annular side eaves; 204. dynamic pressure plate; 205. centering spring; 206. corrugated air seal sleeve; 207. valve stem; 208. electromagnetic actuator; 701. positioning pressure shaft; 702. spring blind cavity; 703. pressure spring. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] See also Figures 1 to 5 The present invention provides a technical solution: a system for collecting signals from MSS, such as Figure 1 As shown in the figure, it includes a main control board, a PC host computer, a signal processing board, an MSS sensor daughter board, a micro pump board and a solenoid valve. The PC host computer and the main control board are connected through a USB serial port communication. A micro pump is integrated on the micro pump board, and the solenoid valve is connected to the micro pump. The solenoid valve can be used to switch the micro pump to be connected to the gas to be tested, or the micro pump to be connected to the air; the micro pump outputs gas to the MSS sensor daughter board, and the MSS sensor daughter board outputs the original signal to the signal processing board. After the signal processing board processes the original signal, the processed signal is input into the main control board again. The main control board transmits the data back to the PC host computer through the USB serial port, and the main control board controls the solenoid valve.

[0027] The main control board is integrated with controllable I / O and pump drive circuit. The controllable I / O is used to access external devices, including fan modules, temperature control modules and automatic gas distribution devices. The main control board is connected to the solenoid valve through the controllable I / O; the pump drive circuit is used to control the micro pump.

[0028] A three-axis sensor is arranged on the micro pump board, and the vibration frequency of the micro pump is monitored by the three-axis sensor to determine the working state of the micro pump. The three-axis sensor is connected with the data of the main control board.

[0029] The MSS sensor sub-board is integrated with an MSS chip substrate and a temperature and humidity sensor. The MSS chip substrate is used to respond to the signal of the gas entering the MSS sensor sub-board, and the temperature and humidity sensor is used to monitor the temperature and humidity values. A total of 8 MSS chip substrates are set on the MSS sensor sub-board, which can collect 8 groups of electrical signals at the same time. The 8 MSS chip substrates can be coated with different materials to test the reactions of different materials to the same gas, thereby speeding up the test progress.

[0030] A voltage acquisition system is provided on the main control board; a multi-stage filtering module and a signal amplification module are provided on the signal processing board. The original signal transmitted from the MSS sensor sub-board is subjected to multi-stage filtering and signal amplification in turn by the multi-stage filtering module and the signal amplification module, and then the signal is output to the voltage acquisition system of the main control board. The multi-stage filtering module and the signal amplification module are both existing technologies in the field and will not be described in detail in this application.

[0031] The voltage acquisition system is equipped with adjustable resistors and voltage conversion chips. The signal acquisition range is adjusted through the adjustable resistor to improve accuracy. The voltage conversion chip is an integrated circuit chip. Its core function is to convert the input voltage signal according to predetermined rules. The voltage conversion chip enables circuits with different power supply voltages in the system to communicate with each other.

[0032] When working, the main control board controls the solenoid valve action through the controllable I / O according to the settings of the PC host computer, and decides which gas to release; the micro pump extracts the gas, and the three-axis sensor monitors the vibration state of the micro pump. The extracted gas is input into the MSS sensor daughter board, which is equipped with the MSS chip substrate to respond to the incoming gas signal. It is also equipped with a temperature and humidity sensor to monitor the temperature and humidity values. The MSS sensor daughter board outputs the original signal into the signal processing board, and after multi-stage filtering and signal amplification, the signal is output to the voltage acquisition system of the main control board. In the voltage acquisition system of the main control board, the acquisition range is adjusted by adjustable resistance to make the acquisition more accurate, and the voltage conversion chip enables the circuits with different power supply voltages in the system to communicate with each other. The signals collected in the voltage acquisition system, the temperature and humidity values ​​on the MSS sensor daughter board, and the mainboard data are transmitted back to the PC host computer through the USB serial port.

[0033] The solenoid valve includes a valve body 1, a switching chamber 2 and a monitoring side chamber 3, the switching chamber 2 and the monitoring side chamber 3 are opened inside the valve body 1, there are two groups of monitoring side chambers 3, and they are respectively connected at the two ends of the switching chamber 2, an air outlet interface 4 and an air inlet interface 5 are fixedly arranged on the surface of the valve body 1, the air outlet interface 4 is connected with the switching chamber 2, there are two groups of air inlet interfaces 5, and they are respectively connected with the monitoring side chamber 3; a closed groove 6 is opened on the inner wall surface of the monitoring side chamber 3, the closed groove 6 is connected with the air inlet interface 5, a sealing one-way disk 7 is arranged in the closed groove 6, and the closed groove 6 is in air-tight contact with the sealing one-way disk 7, an air pressure monitoring probe 8 is embedded in the surface of the valve body 1, a pressure passage 9 is opened inside the valve body 1, and the air pressure monitoring probe 8 is correspondingly connected with the monitoring side chamber 3 through the pressure passage 9.

[0034] A switching sleeve 201 is provided in the switching chamber 2. The switching sleeve 201 is in the shape of a short cylindrical tube. A rubber sleeve 202 is provided on the outer surface of the switching sleeve 201. The switching sleeve 201 is in airtight contact with the inner wall surface of the switching chamber 2 through the rubber sleeve 202. Annular side ridges 203 are symmetrically provided at both ends of the switching sleeve 201. A dynamic pressure plate 204 is provided inside the switching sleeve 201.

[0035] The dynamic pressure plate 204 is symmetrically provided with centering springs 205 on both sides. The centering springs 205 are compressed and arranged between the dynamic pressure plate 204 and the annular side eaves 203. The dynamic pressure plate 204 is located in the middle position of the switching sleeve 201 without being affected by external forces by the elastic force of the centering springs 205. A corrugated gas seal 206 is connected between the dynamic pressure plate 204 and the annular side eaves 203. The corrugated gas seal 206 has a gas sealing function and can be axially retracted, such as Figure 4 As shown in , the corrugated air seal sleeve 206 is a fixed connection seal, has no friction loss, and can achieve long-term stable sealing.

[0036] A valve stem 207 is fixedly provided on the switching sleeve 201, and an electromagnetic actuator 208 is fixedly provided on the outside of the valve body 1. The valve stem 207 is inserted and extended to the outside of the valve body 1 and is transmission-connected to the electromagnetic actuator 208. The electromagnetic actuator 208 can drive the valve stem 207 to axially telescope and move, and the valve stem 207 is in air-tight contact with the valve body 1.

[0037] A positioning pressure shaft 701 is fixedly provided on the sealing one-way disk 7, and a spring blind cavity 702 is opened on the inner wall surface of the monitoring side cavity 3. The positioning pressure shaft 701 is inserted in the spring blind cavity 702, and a pressure spring 703 is arranged inside the spring blind cavity 702. The pressure spring 703 applies an axial elastic thrust to the sealing one-way disk 7 through the positioning pressure shaft 701, so that the sealing one-way disk 7 has an elastic tendency to move toward the closed groove 6. The elastic force of the pressure spring 703 is not easy to be too large to avoid increasing the load of the micro pump. At the same time, when the micro pump opens the sealing one-way disk 7 through negative pressure suction, the negative pressure causes excessive interference to the dynamic pressure plate 204, so that the elastic force of the pressure spring 703 is much smaller than the elastic force of the centering spring 205.

[0038] When the solenoid valve in the present invention is in use, the air outlet interface 4 is connected to the micro pump through a pipeline, and there are two groups of air inlet interfaces 5, which are respectively connected to the background gas and the gas to be tested. The background gas is commonly air. When the micro pump is working, it generates negative pressure suction to extract the air outlet interface 4.

[0039] like Figure 3 and Figure 4 As shown in FIG, the electromagnetic actuator 208 drives the valve stem 207 and the switching sleeve 201 to move axially, so as to realize the switching of the outlet port 4 and the two different inlet ports 5. The sealing one-way disc 7 cooperates with the sealing groove 6 to play a one-way sealing role. When the switching sleeve 201 moves to Figure 4 In the state shown in , the side of the switching sleeve 201 facing the electromagnetic actuator 208 is in a positive pressure state. At this time, the positive pressure pushes the dynamic pressure plate 204 to move away from the electromagnetic actuator 208, thereby increasing the volume and preventing the positive pressure from being too large to block the axial movement of the switching sleeve 201. At the same time, through the elastic force of the centering spring 205, the dynamic pressure plate 204 always has a tendency to elastically reset, thereby maintaining the positive pressure. The two groups of air pressure monitoring probes 8 are respectively connected to their corresponding monitoring side cavities 3. The air pressure monitoring probe 8 connected to the positive pressure can detect the positive pressure, which means that the switching sleeve 201 has completed the action. When the switching sleeve 201 has not moved, if the air pressure monitoring probe 8 connected to the positive pressure detects that the positive pressure gradually disappears, it means that there is a sealing problem between the rubber sleeve 202 and the switching chamber 2 or between the sealing one-way disk 7 and the closed groove 6, especially between the rubber sleeve 202 and the switching chamber 2, which will lead to the risk of mixing background gas and the gas to be tested. No matter where the problem is, when the air pressure monitoring probe 8 connected to the positive pressure detects that the positive pressure gradually disappears, there is a risk of error in the test data, and the solenoid valve needs to be replaced to realize feedback monitoring.

[0040] During reverse switching, the electromagnetic actuator 208 drives the switching sleeve 201 to move in the reverse direction, and the same is true as above.

[0041] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for collecting signals from MSS, comprising a main control board, a PC host computer, a signal processing board, an MSS sensor sub-board, a micro pump board and a solenoid valve, characterized in that: The PC host computer and the main control board are connected via a USB serial port communication. A micro pump is integrated on the micro pump board. The solenoid valve is connected to the micro pump. The solenoid valve can be used to switch the micro pump to be connected to the gas to be measured or to be connected to the air. The micro pump outputs gas to the MSS sensor sub-board, and the MSS sensor sub-board outputs the original signal to the signal processing board. After processing the original signal, the signal processing board inputs the processed signal into the main control board. The main control board transmits the data back to the PC host computer via the USB serial port, and the main control board controls the solenoid valve.

2. The system for collecting signals from a MSS according to claim 1, characterized in that: The main control board is integrated with a controllable I / O and a pump drive circuit. The controllable I / O is used to access external devices, and the external devices include a fan module, a temperature control module and an automatic gas distribution device. The main control board is connected to the solenoid valve through the controllable I / O; the pump drive circuit is used to control the micro pump.

3. The system for collecting signals from a MSS according to claim 1, characterized in that: The micro pump board is provided with a three-axis sensor, through which the vibration frequency of the micro pump is monitored to determine the working state of the micro pump, and the three-axis sensor is data-connected with the main control board.

4. The system for collecting signals from a MSS according to claim 1, characterized in that: The MSS sensor sub-board is integrated with an MSS chip substrate and a temperature and humidity sensor. The MSS chip substrate is used to respond to signals of the gas entering the MSS sensor sub-board, and the temperature and humidity sensor is used to monitor temperature and humidity values.

5. The system for collecting signals from a MSS according to claim 1, characterized in that: The main control board is provided with a voltage acquisition system; the signal processing board is provided with a multi-stage filtering module and a signal amplification module. The original signal transmitted by the MSS sensor sub-board is subjected to multi-stage filtering and signal amplification in turn by the multi-stage filtering module and the signal amplification module, and then the signal is output to the voltage acquisition system of the main control board.

6. The system for collecting signals from a MSS according to claim 5, characterized in that: The voltage acquisition system is provided with an adjustable resistor and a voltage conversion chip. The signal acquisition range is adjusted by the adjustable resistor to improve the accuracy. The voltage conversion chip enables circuits with different power supply voltages in the system to communicate with each other.

7. The system for collecting signals from a MSS according to claim 1, characterized in that: The solenoid valve comprises a valve body (1), a switching chamber (2) and a monitoring side chamber (3); the switching chamber (2) and the monitoring side chamber (3) are arranged inside the valve body (1); two groups of the monitoring side chambers (3) are provided, and are respectively connected to the two ends of the switching chamber (2); an air outlet interface (4) and an air inlet interface (5) are fixedly provided on the surface of the valve body (1); the air outlet interface (4) is connected to the switching chamber (2); the air inlet interface (5) is provided in two groups, and are respectively connected to the monitoring side chamber (3) ) are correspondingly connected; a closed groove (6) is provided on the inner wall surface of the monitoring side cavity (3), the closed groove (6) is connected to the air inlet interface (5), a sealing one-way disk (7) is arranged in the closed groove (6), the closed groove (6) is in airtight contact with the sealing one-way disk (7), an air pressure monitoring probe (8) is embedded on the surface of the valve body (1), a pressure passage (9) is provided inside the valve body (1), and the air pressure monitoring probe (8) is correspondingly connected to the monitoring side cavity (3) through the pressure passage (9).

8. The system for collecting signals from a MSS according to claim 7, characterized in that: A switching sleeve (201) is arranged in the switching chamber (2), the switching sleeve (201) is in the shape of a short cylindrical tube, a rubber sleeve (202) is sleeved on the outer surface of the switching sleeve (201), the switching sleeve (201) is in airtight contact with the inner wall surface of the switching chamber (2) through the rubber sleeve (202), annular side ridges (203) are symmetrically arranged at both ends of the switching sleeve (201), and a dynamic pressure plate (204) is arranged inside the switching sleeve (201).

9. The system for collecting signals from a MSS according to claim 8, characterized in that: Centering springs (205) are symmetrically arranged on both sides of the dynamic pressure plate (204). The centering springs (205) are compressed and arranged between the dynamic pressure plate (204) and the annular side eaves (203). The elastic force of the centering springs (205) enables the dynamic pressure plate (204) to be located in the middle position of the switching sleeve (201) without being affected by external forces. A corrugated air seal sleeve (206) is connected between the dynamic pressure plate (204) and the annular side eaves (203). The corrugated air seal sleeve (206) is connected to the dynamic pressure plate (204) and the annular side eaves (203). 06) plays a gas sealing function, the corrugated gas sealing sleeve (206) can be axially extended and retracted, a valve stem (207) is fixedly provided on the switching sleeve (201), an electromagnetic actuator (208) is fixedly provided on the outside of the valve body (1), the valve stem (207) is inserted and extended to the outside of the valve body (1) and is transmission-connected to the electromagnetic actuator (208), and the valve stem (207) can be driven to axially extend and retract through the electromagnetic actuator (208), and the valve stem (207) is in airtight contact with the valve body (1).

10. The system for collecting signals from MSS according to claim 7, characterized in that: A positioning pressure shaft (701) is fixedly arranged on the sealing one-way disc (7); a spring blind cavity (702) is provided on the inner wall surface of the monitoring side cavity (3); the positioning pressure shaft (701) is inserted into the spring blind cavity (702); a pressure spring (703) is arranged inside the spring blind cavity (702); the pressure spring (703) applies an axial elastic thrust to the sealing one-way disc (7) through the positioning pressure shaft (701), so that the sealing one-way disc (7) has an elastic tendency to move toward the closed groove (6).

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