A system for collecting signals from MSS

Abstract

The present invention relates to the technical field of signal collection systems, and specifically to a system for collecting signals from an MSS, which 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 communicatively connected through a USB serial port. A micro pump is integrated on the micro pump board, and the solenoid valve is communicated with the micro pump. Compared with the official development board that controls the background gas and the gas to be measured through two micro pumps, the present invention uses a combination of one micro pump and a solenoid valve to switch between the background gas and the gas to be measured, which not only saves costs but also ensures that both gases enter through the same pump, and does not increase the detection error due to the differences of the pumps.

Description

Technical Field

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

[0002] The MSS, namely the membrane surface stress sensor, is a new type of sensor element. When target gas molecules diffuse and come into contact with the sensitive membrane surface of the MSS, some gases will adsorb on the membrane surface, and different gases have different adsorption affinities with the membrane surface. Once a gas adsorbs, it will change the molecular distribution state on the film surface, resulting in stress generation in the film, and then causing the film to generate a small deformation to achieve detection. Its unique structure makes it an ideal sensor element, covering various characteristics required by olfactory sensors.

[0003] The application of MSS in the domestic market is relatively small. Except for the official development board of MSS, there are few similar devices, and the price of the existing MSS official board is expensive; two micro-pumps are required, resulting in high manufacturing costs, and the two gases enter through different pumps, and the differences 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 purpose of the present invention is to provide a system for collecting signals from an MSS to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A system for collecting signals from an MSS, including 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. The PC host computer and the main control board are communicatively connected through a USB serial port. The micro-pump board is integrated with a micro-pump, and the solenoid valve is connected to the micro-pump. Through the solenoid valve, it is possible to select and switch the connection between the micro-pump and the gas to be measured, or the connection between the micro-pump and 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 again, and 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.

[0006] The main control board is integrated with a controllable I / O and a pump drive circuit. The controllable I / O is used to connect to external devices. The external devices include a fan module, a temperature control module, and an automatic gas mixing 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] A triaxial sensor is provided on the micro pump board. The vibration frequency of the micro pump is monitored through the triaxial sensor to determine the working state of the micro pump. The triaxial sensor is connected to the main control board for data communication.

[0008] An MSS chip substrate and a temperature and humidity sensor are integrally provided on the MSS sensor daughter board. The MSS chip substrate is used to respond to signals of the gas entering the MSS sensor daughter board, and the temperature and humidity sensor is used to monitor the temperature and humidity values.

[0009] 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. After the original signal transmitted from the MSS sensor daughter board is subjected to multi-stage filtering and signal amplification through the multi-stage filtering module and the signal amplification module in sequence, the signal is output to the voltage acquisition system of the main control board.

[0010] An adjustable resistor and a voltage conversion chip are provided on the voltage acquisition system. The signal acquisition range is adjusted through the adjustable resistor to improve the accuracy. The voltage conversion chip enables the circuits with different 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 the monitoring side chambers in total, and they are respectively connected and arranged at both ends of the switching chamber. An air outlet interface and an air inlet interface are fixedly provided on the surface of the valve body. The air outlet interface is communicated with the switching chamber. There are two groups of the air inlet interfaces in total, and they are respectively connected and communicated with the monitoring side chambers correspondingly; a closed groove is opened on the inner wall surface of the monitoring side chamber, and the closed groove is communicated with the air inlet interface. A sealing check disk is arranged in the closed groove, and the closed groove is in airtight contact with the sealing check disk. A pressure monitoring probe is embedded on the surface of the valve body, and a pressure passage is opened inside the valve body. The pressure monitoring probe is correspondingly communicated with the monitoring side chamber through the pressure passage.

[0012] A switching sleeve is arranged in the switching chamber. The switching sleeve is in the shape of a short cylindrical tube. A rubber sleeve is sleeved on the outer surface of the switching sleeve. 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 respectively, 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:

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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

[0020] Figure 1 This is a schematic diagram of the system modules for collecting signals from MSS according to the present invention.

[0021] Figure 2 Schematic diagram of the solenoid valve of the present invention.

[0022] Figure 3 It is a three-dimensional half-section schematic diagram of the solenoid valve of the present invention.

[0023] Figure 4 for Figure 3 A magnified schematic diagram of area A in the middle.

[0024] Figure 5 It is a three-dimensional half-section top view of the solenoid valve of the present invention.

[0025] 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

[0026] 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.

[0027] See also Figures 1 to 5 The present invention provides a technical solution: a system for collecting signals from MSS, such as Figure 1As shown in the figure, it includes 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. The PC host computer and the main control board are connected through USB serial communication. A micro pump is integrated on the micro pump board. The solenoid valve is connected to the micro pump. Through the solenoid valve, it is possible to select and switch the connection between the micro pump and the gas to be measured, or the connection between the micro pump and 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 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.

[0028] A controllable I / O and a pump drive circuit are integrated on the main control board. The controllable I / O is used to connect to external devices. The external devices include a fan module, a temperature control module and an automatic gas mixing 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.

[0029] A three-axis sensor is provided on the micro pump board. The vibration frequency of the micro pump is monitored through the three-axis sensor to determine the working state of the micro pump. The three-axis sensor is connected to the main control board for data transmission.

[0030] An MSS chip substrate and a temperature and humidity sensor are integrated on the MSS sensor sub-board. 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 provided on the MSS sensor sub-board, which can simultaneously collect 8 groups of electrical signals. Different materials can be coated on the 8 MSS chip substrates to test the reaction of different materials to the same gas, thus accelerating the test progress.

[0031] 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 through the multi-stage filtering module and the signal amplification module in sequence, 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 prior arts in the field, and will not be elaborated herein in this application.

[0032] An adjustable resistor and a voltage conversion chip are provided on the voltage acquisition system. The signal acquisition range is adjusted through the adjustable resistor to improve the accuracy. The voltage conversion chip is an integrated circuit chip, and its core function is to convert the input voltage signal according to a predetermined rule. The voltage conversion chip enables the circuits with different supply voltages in the system to communicate with each other.

[0033] During operation, the main control board autonomously controls the solenoid valve to act through controllable I / O according to the settings of the PC host computer, determining which gas to release; the micro pump extracts gas, and at the same time, the three-axis sensor monitors the vibration state of the micro pump. The extracted gas is input into the MSS sensor daughter board. The MSS sensor daughter board is loaded with the MSS chip substrate to respond to the incoming gas signal, and it is also loaded 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. 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 through an adjustable resistor to make the acquisition more accurate. The voltage conversion chip enables the circuits with different supply voltages in the system to communicate with each other. The signals acquired in the voltage acquisition system, the temperature and humidity values on the MSS sensor daughter board, and the main board data are sent back to the PC host computer through the USB serial port.

[0034] 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 the monitoring side chambers 3, and they are respectively connected and arranged at both 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 communicated with the switching chamber 2. There are two groups of the air inlet interfaces 5, and they are respectively correspondingly communicated with the monitoring side chambers 3. A closed groove 6 is opened on the inner wall surface of the monitoring side chamber 3. The closed groove 6 is communicated with the air inlet interface 5. A sealed one-way disk 7 is arranged in the closed groove 6. The closed groove 6 is in airtight contact with the sealed one-way disk 7. A pressure monitoring probe 8 is embedded on the surface of the valve body 1. A pressure passage 9 is opened inside the valve body 1. The pressure monitoring probe 8 is correspondingly communicated with the monitoring side chamber 3 through the pressure passage 9.

[0035] 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 eaves 203 are symmetrically arranged at both ends of the switching sleeve 201 respectively. A dynamic pressure plate 204 is arranged inside the switching sleeve 201.

[0036] 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. Through the elastic force of the centering springs 205, the dynamic pressure plate 204 is 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 functions to seal gas. The corrugated air seal sleeve 206 can axially expand and contract. As Figure 4 shown, the corrugated air seal sleeve 206 is a fixed connection seal, without frictional loss, and can achieve long-term stable sealing.

[0037] A valve rod 207 is fixedly arranged on the switching sleeve 201. An electromagnetic actuator 208 is fixedly arranged outside the valve body 1. The valve rod 207 penetrates and extends outside the valve body 1 and is in transmission connection with the electromagnetic actuator 208. The electromagnetic actuator 208 can drive the valve rod 207 to axially extend and retract. The valve rod 207 is in airtight contact with the valve body 1.

[0038] A positioning press shaft 701 is fixedly arranged on the sealing check disk 7. A spring blind cavity 702 is formed on the inner wall surface of the monitoring side cavity 3. The positioning press shaft 701 is inserted into the spring blind cavity 702. A pressing spring 703 is arranged inside the spring blind cavity 702. The pressing spring 703 applies an axial elastic thrust to the sealing check disk 7 through the positioning press shaft 701, so that the sealing check disk 7 has an elastic tendency to move into the closing groove 6. The elastic force of the pressing spring 703 is not too large to avoid increasing the load of the micropump. At the same time, when the micropump opens the sealing check disk 7 by negative pressure suction, the negative pressure will not cause too much interference to the dynamic pressure disk 204, so that the elastic force of the pressing spring 703 is much smaller than the elastic force of the centering spring 205.

[0039] When the electromagnetic valve in the present invention is in use, the air outlet interface 4 is communicated with the micropump through a pipeline. There are two groups of air inlet interfaces 5 in total. The two groups of air inlet interfaces 5 are respectively communicated with the background gas and the gas to be measured. The background gas is usually air. When the micropump is working, it generates a negative pressure suction to extract the air outlet interface 4.

[0040] As Figure 3 and Figure 4 shown, the electromagnetic actuator 208 drives the valve rod 207 and the switching sleeve 201 to axially move, so as to realize the switching connection between the air outlet interface 4 and the two different air inlet interfaces 5. The cooperation between the sealing check disk 7 and the closing groove 6 plays a role of one-way closing. When the switching sleeve 201 moves to Figure 4When in the state shown, 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, realizing an increase in volume, to avoid excessive positive pressure blocking the axial movement of the switching sleeve 201. At the same time, due to the elastic force of the centering spring 205, the dynamic pressure plate 204 always has a tendency of elastic reset, thereby maintaining the positive pressure. The two groups of air pressure monitoring probes 8 are respectively communicated with their corresponding monitored side cavities 3. The air pressure monitoring probe 8 communicated with the positive pressure can detect the positive pressure. At this time, it indicates that the switching sleeve 201 has completed the action. In the case where the switching sleeve 201 does not move, if the air pressure monitoring probe 8 communicated with the positive pressure detects that the positive pressure gradually disappears, it indicates that there is a sealing problem between the rubber sleeve 202 and the switching cavity 2 or between the sealing one-way disc 7 and the closed groove 6. Especially when there is a sealing problem between the rubber sleeve 202 and the switching cavity 2, it will cause the risk of mixing of the background gas and the gas to be measured. No matter where the problem is, when the air pressure monitoring probe 8 communicated with the positive pressure detects that the positive pressure gradually disappears, there is a risk of error in the test data at this time, and the solenoid valve needs to be replaced to achieve feedback monitoring.

[0041] During reverse switching, the electromagnetic actuator 208 drives the switching sleeve 201 to move in the reverse direction, and the same principle applies above.

[0042] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. 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, and the micro pump can be switched to be connected to the gas to be measured or to be connected to the air through the solenoid valve; 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, the signal processing board processes the original signal, and then inputs the processed signal to the main control board, 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; 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 and arranged at 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); and two groups of the air inlet interfaces (5) are provided, and are respectively corresponding to the monitoring side chambers (3). The monitoring side cavity (3) is connected with the air inlet port (5); a closed groove (6) is provided on the inner wall surface of the monitoring side cavity (3); the closed groove (6) is connected with the air inlet port (5); a sealing one-way disc (7) is provided in the closed groove (6); the closed groove (6) and the sealing one-way disc (7) are in airtight contact; a switching sleeve (201) is provided in the switching cavity (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 sealed by a rubber sleeve The rubber sleeve (202) is in airtight contact with the inner wall surface of the switching chamber (2); annular side ridges (203) are symmetrically arranged at both ends of the switching sleeve (201); a dynamic pressure plate (204) is arranged inside the switching sleeve (201); 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 ridges (203); the dynamic pressure plate (204) is elastically pressed by the centering springs (205). 04) is in the middle position of the switching sleeve (201) when not affected by external forces; 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 valve stem (207) can be driven to axially telescope and move through the electromagnetic actuator (208), and the valve stem (207) is in airtight contact with the valve body (1).

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: An air pressure monitoring probe (8) is embedded in 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 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) performs a gas sealing function, and the corrugated air seal sleeve (206) is axially retractable.

9. The system for collecting signals from a 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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