Automobile harmful gas detection system and method

Abstract

The present invention relates to a vehicle harmful gas detection system and method thereof. The system includes a laser generator, a photosensitive detector, a signal processing circuit, and a system control circuit. The system includes a laser generator and at least one photosensitive detector. The laser generator and the photosensitive detector are both embedded in the vehicle compartment and symmetrically distributed on both sides of the vehicle compartment axis. The laser generator and a photosensitive detector are coaxially distributed. The photosensitive detectors are connected in parallel with each other and are electrically connected to the signal processing circuit and the system control circuit. The signal processing circuit and the system control circuit are both in the vehicle compartment. The system control circuit is also electrically connected to the laser generator, the signal processing circuit, and the vehicle driving computer circuit. The present invention can effectively meet the needs of supporting the operation of various vehicle equipment; the present invention has high detection accuracy, and can accurately detect the air components and the concentrations of each component in the vehicle synchronously with the operation of the vehicle and effectively warn, thereby greatly improving the safety and reliability of vehicle operation.

Description

Technical Field

[0001] The invention relates to an automobile harmful gas detection system and a method thereof, belonging to the technical field of automobile safety protection equipment. Background Art

[0002] With the rapid development of my country's automobile industry, the number of cars in my country has also greatly increased. As the main means of transportation for people, how to drive a car safely has become the most important issue. According to the survey, 43% of traffic accidents each year are caused by drunk driving. At the same time, because the materials of the vehicle itself are easy to volatilize toxic and harmful gases in a high temperature environment, the materials carried by the vehicle often volatilize toxic and harmful gases, and the vehicle will pass through the path that is harmful to the human body during transportation, the safety of vehicle use has also been greatly affected. In response to this problem, the current main detection is through traditional alcohol sensors, air sensors and other equipment. Although it can meet the needs of use to a certain extent, on the one hand, the equipment structure is complex, the vehicle applicability is poor, and the vehicle structure needs to be greatly modified when it is installed and applied. At the same time, it can only detect specific gases, and the flexibility and convenience of application are relatively insufficient. On the other hand, the detection accuracy of the traditional sensor system is poor during operation, and it can often only roughly detect the gas composition, but cannot accurately detect the concentration of each component gas, so it is still difficult to effectively meet the actual application needs. Summary of the invention

[0003] In order to solve the deficiencies in the prior art, the present invention provides a vehicle harmful gas detection system and method thereof. The present invention has high detection accuracy and can accurately detect the air components and concentrations of each component in the vehicle synchronously with the operation of the vehicle and provide effective warnings, thereby greatly improving the safety and reliability of vehicle operation.

[0004] A vehicle harmful gas detection system includes a laser generator, a photosensitive detector, a signal processing circuit, and a system control circuit. The laser generator and the photosensitive detector are both embedded in a vehicle compartment and symmetrically distributed on both sides of the vehicle compartment axis. The laser generator and a photosensitive detector are coaxially distributed, the photosensitive detectors are connected in parallel with each other, and are electrically connected to the signal processing circuit and the system control circuit. The signal processing circuit and the system control circuit are both in the vehicle compartment, and the system control circuit is also electrically connected to the laser generator, the signal processing circuit, and the vehicle driving computer circuit.

[0005] Furthermore, the number of the photosensitive detectors is one or at least three. When there are three or more photosensitive detectors, one of the photosensitive detectors is coaxially distributed with the laser generator, and the remaining photosensitive detectors are evenly distributed around the optical axis of the laser generator, intersecting with the optical axis of the laser generator at an angle of 10°-90°, and the photosensitive detectors are connected in parallel with each other.

[0006] Furthermore, the laser generator includes a carrier shell, a brightness sensor, a laser, a semiconductor refrigeration mechanism, and a terminal block. The carrier shell is a closed cavity structure with a rectangular cross-section. There are at least two lasers, which are embedded in the front end face of the carrier shell, and their optical axes are parallel to each other and perpendicular to the front end face of the carrier shell. The brightness sensor is embedded in the upper end face of the carrier shell, and its optical axis forms an angle of 0° - 90° with the optical axis of the laser. The semiconductor refrigeration mechanism is embedded in the carrier shell, its refrigeration end is located at the rear end face of each laser and is in contact with the heat exchange plate, and heat dissipation holes are provided on the corresponding rear end face of the carrier shell at the front end. The terminal block is embedded in the rear end face of the carrier shell and is electrically connected to the brightness sensor, the laser, the semiconductor refrigeration mechanism, and the system control circuit respectively.

[0007] Furthermore, the photosensitive detector includes a base, a photodetector, a gas composition sensor, a temperature and humidity sensor, a preprocessing circuit, a terminal block, and a serial communication terminal. The base is a structure with a "凵" - shaped cross-section. The photodetector and the preprocessing circuit are both embedded in the base and connected to the bottom of the base groove, and they are coaxially distributed between the base and the photodetector. There is at least one gas composition sensor and at least one temperature and humidity sensor, which are arranged around the axis of the base and embedded in the outer side face of the base. There is at least one terminal block and at least one serial communication terminal, which are embedded in the lower end face of the base. The photodetector, the gas composition sensor, the temperature and humidity sensor, the terminal block, and the serial communication terminal are all electrically connected to the preprocessing circuit, and the terminal block and the serial communication terminal are respectively electrically connected to the signal processing circuit and the system control circuit.

[0008] Furthermore, the preprocessing circuit includes a multi - path voltage stabilizing circuit, a serial communication circuit, a filtering and rectifying circuit, a signal amplifying circuit, an electronic switch circuit, and a central processing circuit based on an industrial single - chip microcomputer. The central processing circuit based on the industrial single - chip microcomputer is electrically connected to the multi - path voltage stabilizing circuit, the serial communication circuit, the filtering and rectifying circuit, the signal amplifying circuit, and the electronic switch circuit respectively. The multi - path voltage stabilizing circuit is also electrically connected to the terminal block. The electronic switch circuit is also electrically connected to the photodetector, the gas composition sensor, the temperature and humidity sensor, and the system control circuit respectively through the terminal block. The serial communication circuit is electrically connected to the serial communication terminal, the filtering and rectifying circuit, and the signal amplifying circuit, and is electrically connected to the signal processing circuit through the serial communication terminal.

[0009] Furthermore, the signal processing circuit is a circuit system with a lock - in amplifier as the core.

[0010] Furthermore, the system control circuit is a circuit system based on any one of a DSP chip and an FPGA chip, and the system control circuit is further provided with a MOS drive circuit, a bus circuit, an electronic switch circuit based on IGBT, an I / O interface circuit, a crystal oscillator clock circuit, a serial communication circuit, a multi-channel voltage-regulated power supply and a TDLAS unit. The system control circuit is electrically connected to the MOS drive circuit, the bus circuit and the crystal oscillator clock circuit respectively, and the bus circuit is electrically connected to the electronic switch circuit based on IGBT, the I / O interface circuit, the serial communication circuit and the multi-channel voltage-regulated power supply respectively. The electronic switch circuit based on IGBT is also electrically connected to the I / O interface circuit, the serial communication circuit and the multi-channel voltage-regulated power supply respectively, and the I / O interface circuit and the serial communication circuit are electrically connected to the laser generator, the photosensitive detector and the signal processing circuit respectively. There is at least one TDLAS unit, and each TDLAS unit is connected in parallel with each other and is electrically connected to the system control circuit through the electronic switch circuit based on IGBT, and each TDLAS unit is also electrically connected to the I / O interface circuit, the serial communication circuit and the multi-channel voltage-regulated power supply respectively.

[0011] A method for using a vehicle harmful gas detection system comprises the following steps:

[0012] S1, system prefabrication, first install the laser generator and photosensitive detector in the vehicle cab and compartment respectively, then embed the signal processing circuit and system control circuit in the vehicle's driving computer circuit, and make the signal processing circuit and system control circuit electrically connected to the vehicle's driving computer respectively;

[0013] S2, system setting, after completing step S1, first input the gas composition identification calculation program into the system control circuit, and then perform filtering setting on the signal processing circuit to adjust the waveform and signal strength of the output signal of the signal processing circuit;

[0014] S3, detection operation, after the vehicle is started, the laser generator, photosensitive detector, signal processing circuit, and system control circuit operate synchronously. First, the laser generator generates a laser beam in the vehicle interior. When the energy of the laser beam passes through the vehicle, the gas components, solid components, and liquid components in the air environment absorb part of the laser energy of the corresponding band and transmit it to the photosensitive detector. After passing through the signal processing circuit, the laser signal is converted into a first harmonic electrical signal; at the same time, the gas components, solid components, liquid components in the air environment in the vehicle and the corresponding vehicle body structure, objects, and personnel in the vehicle scatter the laser beam. The diffusely reflected, scattered and diffusely reflected laser energies are received synchronously by the photosensitive detector at the same time, and the laser signal is converted into a second harmonic electrical signal by the signal processing circuit, and finally the first harmonic telecommunication signal and the second harmonic electrical signal are transmitted to the system control circuit, and the system control circuit and the TDLAS unit system of the system control circuit perform calculations and identification on the received first harmonic telecommunication signal and second harmonic electrical signal, and the type and concentration of the air components in the car can be obtained according to the attenuation of the laser energy, and the gas components that threaten the driving safety can be alarmed for harmful gases through the system control circuit and the vehicle's driving computer.

[0015] The present invention generates a laser beam in the vehicle interior space by a laser generator. When the energy of the laser beam passes through the vehicle interior, gas components, solid components and liquid components in the air environment absorb part of the laser energy of the corresponding band and transmit it to a photosensitive detector. The laser signal is converted into a first harmonic electric signal after passing through a signal processing circuit. At the same time, the gas components, solid components and liquid components in the air environment in the vehicle interior and the corresponding vehicle body structure, articles and personnel in the vehicle scatter and diffusely reflect the laser beam. The scattered and diffusely reflected laser energy is synchronously received by the photosensitive detector at the same time, and the laser signal is converted into a second harmonic electric signal after passing through a signal processing circuit. Finally, the first harmonic telecommunication signal and the second harmonic electric signal are transmitted to a system control circuit. The system control circuit and a TDLAS unit system of the system control circuit perform calculation and identification on the received first harmonic telecommunication signal and the second harmonic electric signal. According to the attenuation of the laser energy, the type and concentration of the air components in the vehicle compartment can be obtained, and a harmful gas alarm is performed for the gas components threatening the driving safety through the system control circuit and the vehicle driving computer. The system of the present invention has a simple structure, is flexible and convenient to install, maintain and operate, has little change to the vehicle structure, has good versatility, and can effectively meet the needs of supporting operation of various vehicle equipment; at the same time, the detection operation of the present invention has high accuracy, and can accurately detect the air components and concentrations of each component in the vehicle synchronously with the operation of the vehicle and effectively warn, thereby greatly improving the safety and reliability of vehicle operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments;

[0017] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0018] Figure 2 is a schematic diagram of the preprocessing circuit structure;

[0019] Figure 3 It is a schematic diagram of the system control circuit structure;

[0020] Figure 4 It is a schematic diagram of the data transmission process of the present invention.

[0021] The numbers in the figure are: 1. Laser generator; 2. Photosensitive detector; 3. Signal processing circuit; 4. System control circuit; 11. Carrying shell; 12. Brightness sensor; 13. Laser; 14. Semiconductor refrigeration mechanism; 15. Wiring terminal; 16. Heat exchange plate; 17. Heat dissipation hole; 21. Base; 22. Photodetector; 23. Gas composition sensor; 24. Temperature and humidity sensor; 25. Preprocessing circuit; 26. Serial communication terminal. DETAILED DESCRIPTION

[0022] In order to facilitate the construction of the technical means, creative features, objectives and effects achieved by the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0023] like Figure 1 As shown, a vehicle harmful gas detection system includes a laser generator 1, a photosensitive detector 2, a signal processing circuit 3, and a system control circuit 4. There is one laser generator 1, one or at least three photosensitive detectors 2, and the laser generator 1 and the photosensitive detector 2 are embedded in the car and symmetrically distributed on both sides of the car axis. The laser generator 1 is coaxially distributed with a photosensitive detector 2, and the photosensitive detectors 2 are connected in parallel with each other and are electrically connected to the signal processing circuit 3 and the system control circuit 4. The signal processing circuit 3 and the system control circuit 4 are both in the car, and the system control circuit 4 is also electrically connected to the laser generator 1, the signal processing circuit 3 and the vehicle driving computer circuit.

[0024] In this embodiment, when there are more than three photosensitive detectors 2, one of the photosensitive detectors 2 is coaxially distributed with the laser generator 1, and the remaining photosensitive detectors 2 are evenly distributed around the optical axis of the laser generator 1, intersecting with the optical axis of the laser generator 1 and forming an angle of 10°-90°, and the photosensitive detectors 2 are connected in parallel with each other.

[0025] It should be noted that the laser generator 1 includes a carrier shell 11, a brightness sensor 12, a laser 13, a semiconductor refrigeration mechanism 14, and a terminal block 15. The carrier shell 11 is a closed cavity structure with a rectangular cross-section. There are at least two lasers 13, which are embedded in the front end face of the carrier shell 11, and their optical axes are parallel to each other and perpendicular to the front end face of the carrier shell 11. The brightness sensor 12 is embedded in the upper end face of the carrier shell 11, and its optical axis forms an angle of 0°-90° with the optical axis of the laser 13. The semiconductor refrigeration mechanism 14 is embedded in the carrier shell 11, and its refrigeration end is located at the rear end face of each laser 13 and abuts against it through a heat exchange plate 16. A heat dissipation hole 17 is provided at the rear end face of the corresponding carrier shell 11 at the front end. The terminal block 15 is embedded in the rear end face of the carrier shell 11 and is electrically connected to the brightness sensor 12, the laser 13, the semiconductor refrigeration mechanism 14, and the system control circuit 4 respectively.

[0026] It should be emphasized that the photosensitive detector 2 includes a base 21, a photodetector 22, a gas composition sensor 23, a temperature and humidity sensor 24, a preprocessing circuit 25, a terminal block 15, and a serial communication terminal 26. The base 21 is a structure with a "U"-shaped groove cross-section. The photodetector 22 and the preprocessing circuit 25 are both embedded in the base 21 and connected to the bottom of the groove of the base 21, and the base 21 and the photodetector 22 are coaxially distributed. There is at least one gas composition sensor 23 and at least one temperature and humidity sensor 24, which are evenly distributed around the axis of the base 21 and embedded in the outer side surface of the base 21. There is at least one terminal block 15 and at least one serial communication terminal 26, which are embedded in the lower end face of the base 21. The photodetector 22, the gas composition sensor 23, the temperature and humidity sensor 24, the terminal block 15, and the serial communication terminal 26 are all electrically connected to the preprocessing circuit 25, and the terminal block 15 and the serial communication terminal 26 are respectively electrically connected to the signal processing circuit 3 and the system control circuit 4.

[0027] As Figure 2 shown, at the same time, the preprocessing circuit 25 includes a multi-channel voltage stabilizing circuit, a serial communication circuit, a filtering and rectifying circuit, a signal amplifying circuit, an electronic switch circuit, and a central processing circuit based on an industrial single-chip microcomputer. The central processing circuit based on the industrial single-chip microcomputer is electrically connected to the multi-channel voltage stabilizing circuit, the serial communication circuit, the filtering and rectifying circuit, the signal amplifying circuit, and the electronic switch circuit respectively. The multi-channel voltage stabilizing circuit is electrically connected to the terminal block 15. The electronic switch circuit is electrically connected to the photodetector 22, the gas composition sensor 23, the temperature and humidity sensor 24, and the system control circuit 4 respectively through the terminal block 15. The serial communication circuit is electrically connected to the serial communication terminal 26, the filtering and rectifying circuit, and the signal amplifying circuit, and is electrically connected to the signal processing circuit 3 through the serial communication terminal 26.

[0028] In this embodiment, the signal processing circuit 3 is a circuit system with a lock-in amplifier as its core.

[0029] like Figure 3 As shown, the system control circuit 4 is a circuit system based on any one of a DSP chip and an FPGA chip, and the system control circuit 4 is further provided with a MOS drive circuit, a bus circuit, an electronic switch circuit based on IGBT, an I / O interface circuit, a crystal oscillator clock circuit, a serial communication circuit, a multi-channel voltage-stabilized power supply and a TDLAS unit. The system control circuit 4 is electrically connected to the MOS drive circuit, the bus circuit and the crystal oscillator clock circuit respectively, and the bus circuit is electrically connected to the electronic switch circuit based on IGBT, the I / O interface circuit, the serial communication circuit, the multi-channel voltage-stabilized power supply and the TDLAS unit respectively. The voltage-stabilized power supply is electrically connected, the IGBT-based electronic switch circuit is electrically connected to the I / O interface circuit, the serial communication circuit, and the multi-channel voltage-stabilized power supply, and the I / O interface circuit and the serial communication circuit are electrically connected to the laser generator 1, the photosensitive detector 2, and the signal processing circuit 3, respectively. There is at least one TDLAS unit, and each TDLAS unit is connected in parallel with each other and is electrically connected to the system control circuit 4 through the IGBT-based electronic switch circuit, and each TDLAS unit is electrically connected to the I / O interface circuit, the serial communication circuit, and the multi-channel voltage-stabilized power supply.

[0030] like Figure 4 As shown, a method for using a vehicle harmful gas detection system comprises the following steps:

[0031] S1, system prefabrication, firstly install a laser generator 1 and a photosensitive detector 2 in the vehicle cab and the vehicle compartment respectively, then embed a signal processing circuit 3 and a system control circuit 4 in the vehicle's driving computer circuit, and make the signal processing circuit 3 and the system control circuit 4 electrically connected to the vehicle's driving computer respectively;

[0032] S2, system setting, after completing step S1, firstly input the gas composition identification calculation program into the system control circuit 4, then perform filtering setting on the signal processing circuit 3, so as to adjust the waveform and signal strength of the output signal of the signal processing circuit 3;

[0033] S3, detection operation, after the vehicle is started, the laser generator 1, the photosensitive detector 2, the signal processing circuit 3, and the system control circuit 4 operate synchronously. First, the laser generator 1 generates a laser beam in the vehicle interior. When the energy of the laser beam passes through the vehicle, the gas components, solid components, and liquid components in the air environment absorb part of the laser energy of the corresponding band and transmit it to the photosensitive detector 2. After passing through the signal processing circuit 3, the laser signal is converted into a first harmonic electrical signal; at the same time, the gas components, solid components, and liquid components in the air environment in the vehicle and the corresponding vehicle body structure, objects, and people in the vehicle scatter the laser beam. The scattered and diffusely reflected laser energies are received synchronously by the photosensitive detector 2 at the same time, and the laser signal is converted into a second harmonic electrical signal by the signal processing circuit 3, and finally the first harmonic telecommunication signal and the second harmonic electrical signal are transmitted to the system control circuit 4, and the system control circuit 4 and the TDLAS unit system of the system control circuit 4 perform calculations and identification on the received first harmonic telecommunication signal and the second harmonic electrical signal, and the type and concentration of the air components in the car can be obtained according to the attenuation of the laser energy, and the gas components that threaten the driving safety can be used through the system control circuit 4 and the vehicle's driving computer to send a harmful gas alarm.

[0034] In this embodiment, when installing the laser generator 1 and the photosensitive detector 2, at least one laser beam of the laser generator 1 can be directly received by the photosensitive detector 2, and the laser beam is located between the vehicle driving seat and the vehicle front windshield, and the height is 5-20 cm above the steering wheel.

[0035] Meanwhile, in the specific implementation of the present invention, the laser generator 1 adopts an intermittent working system, performs laser irradiation once every 10-60 minutes, and each laser irradiation time is 1-10 minutes.

[0036] The present invention generates a laser beam in the vehicle interior space by a laser generator. When the energy of the laser beam passes through the vehicle interior, gas components, solid components and liquid components in the air environment absorb part of the laser energy of the corresponding band and transmit it to a photosensitive detector. The laser signal is converted into a first harmonic electric signal after passing through a signal processing circuit. At the same time, the gas components, solid components and liquid components in the air environment in the vehicle interior and the corresponding vehicle body structure, articles and personnel in the vehicle scatter and diffusely reflect the laser beam. The scattered and diffusely reflected laser energy is synchronously received by the photosensitive detector at the same time, and the laser signal is converted into a second harmonic electric signal after passing through a signal processing circuit. Finally, the first harmonic telecommunication signal and the second harmonic electric signal are transmitted to a system control circuit. The system control circuit and a TDLAS unit system of the system control circuit perform calculation and identification on the received first harmonic telecommunication signal and the second harmonic electric signal. According to the attenuation of the laser energy, the type and concentration of the air components in the vehicle compartment can be obtained, and a harmful gas alarm is performed for the gas components threatening the driving safety through the system control circuit and the vehicle driving computer. The system of the present invention has a simple structure, is flexible and convenient to install, maintain and operate, has little change to the vehicle structure, has good versatility, and can effectively meet the needs of supporting operation of various vehicle equipment; at the same time, the detection operation of the present invention has high accuracy, and can accurately detect the air components and concentrations of each component in the vehicle synchronously with the operation of the vehicle and effectively warn, thereby greatly improving the safety and reliability of vehicle operation.

[0037] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for using a vehicle harmful gas detection system, characterized in that: The automobile harmful gas detection system comprises a laser generator (1), a photosensitive detector (2), a signal processing circuit (3), and a system control circuit (4), wherein the laser generator (1) is one, the photosensitive detector (2) is at least one, and the laser generator (1) and the photosensitive detector (2) are both embedded in the vehicle and symmetrically distributed on both sides of the vehicle axis, the laser generator (1) and a photosensitive detector (2) are coaxially distributed, the photosensitive detectors (2) are connected in parallel with each other, and are electrically connected to the signal processing circuit (3) and the system control circuit (4), and the signal processing circuit (3) and the system control circuit (4) are connected to each other in parallel. The system control circuit (4) is located in the vehicle compartment, and the system control circuit (4) is electrically connected to the laser generator (1), the signal processing circuit (3) and the vehicle driving computer circuit; at least one laser beam of the laser generator (1) can be directly received by the photosensitive detector (2), and the laser beam is located between the vehicle driving position and the front windshield of the vehicle, and the height is 5-20 cm above the steering wheel; the photosensitive detector (2) is one or at least three, and when the photosensitive detector (2) is three or more, one of the photosensitive detectors (2) is coaxially distributed with the laser generator (1), and the remaining photosensitive detectors (2) are coaxially distributed with the laser generator (1), and the remaining photosensitive detectors (2) are coaxially distributed with the laser generator (1). The photosensitive detectors (2) are evenly distributed around the optical axis of the laser generator (1), intersecting with the optical axis of the laser generator (1) and forming an angle of 10° to 90°, and the photosensitive detectors (2) are connected in parallel with each other; the laser generator (1) comprises a carrier shell (11), a brightness sensor (12), a laser (13), a semiconductor refrigeration mechanism (14) and a terminal (15); the carrier shell (11) is a closed cavity structure with a rectangular cross section; at least two lasers (13) are embedded in the front end surface of the carrier shell (11) and their optical axes are parallel to each other and perpendicular to the front end surface of the carrier shell (11). The brightness sensor (12) is embedded in the upper end surface of the carrier shell (11), and its optical axis forms an angle of 0°-90° with the optical axis of the laser (13); the semiconductor refrigeration mechanism (14) is embedded in the carrier shell (11), and its refrigeration end is located at the rear end surface of each laser (13) and is abutted against each other through a heat exchange plate (16); a heat dissipation hole (17) is provided on the rear end surface of the carrier shell (11) corresponding to the front end surface; and the wiring terminal (15) is embedded in the rear end surface of the carrier shell (11) and is electrically connected to the brightness sensor (12), the laser (13), the semiconductor refrigeration mechanism (14) and the system control circuit (4) respectively;The described photosensitive detector (2) includes a base (21), a photodetector (22), a gas composition sensor (23), a temperature and humidity sensor (24), a preprocessing circuit (25), a terminal block (15), and a serial communication terminal (26). The base (21) has a cross-section in a "U"-shaped groove structure. The photodetector (22) and the preprocessing circuit (25) are both embedded in the base (21) and connected to the bottom of the groove of the base (21), and the base (21) and the photodetector (22) are coaxially distributed. There is at least one gas composition sensor (23) and at least one temperature and humidity sensor (24), which are evenly arranged around the axis of the base (21) and embedded in the outer side surface of the base (21). There is at least one terminal block (15) and at least one serial communication terminal (26), which are embedded in the lower end surface of the base (21). The photodetector (22), the gas composition sensor (23), the temperature and humidity sensor (24), the terminal block (15), and the serial communication terminal (26) are all electrically connected to the preprocessing circuit (25), and the terminal block (15) and the serial communication terminal (26) are respectively electrically connected to the signal processing circuit (3) and the system control circuit (4). The preprocessing circuit (25) includes a multi-channel voltage stabilizing circuit, a serial communication circuit, a filtering and rectifying circuit, a signal amplifying circuit, an electronic switch circuit, and a central processing circuit based on an industrial single-chip microcomputer. The central processing circuit based on the industrial single-chip microcomputer is electrically connected to the multi-channel voltage stabilizing circuit, the serial communication circuit, the filtering and rectifying circuit, the signal amplifying circuit, and the electronic switch circuit respectively. The multi-channel voltage stabilizing circuit is also electrically connected to the terminal block (15). The electronic switch circuit is also electrically connected to the photodetector (22), the gas composition sensor (23), the temperature and humidity sensor (24), and the system control circuit (4) respectively through the terminal block (15). The serial communication circuit is electrically connected to the serial communication terminal (26), the filtering and rectifying circuit, and the signal amplifying circuit, and is electrically connected to the signal processing circuit (3) through the serial communication terminal (26).The system control circuit (4) is a circuit system based on any one of a DSP chip and an FPGA chip, and the system control circuit (4) is further provided with a MOS drive circuit, a bus circuit, an electronic switch circuit based on an IGBT, an I / O interface circuit, a crystal oscillator clock circuit, a serial communication circuit, a multi-channel voltage-stabilized power supply and a TDLAS unit. The system control circuit (4) is electrically connected to the MOS drive circuit, the bus circuit and the crystal oscillator clock circuit respectively, and the bus circuit is electrically connected to the electronic switch circuit based on an IGBT, the I / O interface circuit, the serial communication circuit, the multi-channel voltage-stabilized power supply and the TDLAS unit respectively. The IGBT-based electronic switch circuit is electrically connected to an I / O interface circuit, a serial communication circuit, and a multi-channel voltage-stabilized power supply, and the I / O interface circuit and the serial communication circuit are electrically connected to a laser generator (1), a photosensitive detector (2), and a signal processing circuit (3), respectively. There is at least one TDLAS unit, and each TDLAS unit is connected in parallel with each other and is electrically connected to a system control circuit (4) through an IGBT-based electronic switch circuit, and each TDLAS unit is electrically connected to the I / O interface circuit, the serial communication circuit, and the multi-channel voltage-stabilized power supply, respectively. The method for using the automobile harmful gas detection system comprises the following steps: S1, system prefabrication, firstly installing a laser generator (1) and a photosensitive detector (2) in a vehicle cab and a vehicle compartment respectively, then embedding a signal processing circuit (3) and a system control circuit (4) in a vehicle driving computer circuit, and electrically connecting the signal processing circuit (3) and the system control circuit (4) to the vehicle driving computer respectively; S2, system setting, after completing step S1, firstly, the gas composition identification calculation program is input into the system control circuit (4), and then the signal processing circuit (3) is filtered and set to adjust the waveform and signal strength of the output signal of the signal processing circuit (3); S3, detection operation, after the vehicle is started, the laser generator (1), the photosensitive detector (2), the signal processing circuit (3), and the system control circuit (4) operate synchronously. First, the laser generator (1) generates a laser beam in the vehicle interior. When the energy of the laser beam passes through the vehicle interior, the gas components, solid components, and liquid components in the air environment absorb part of the laser energy of the corresponding wavelength band and transmit it to the photosensitive detector (2). After passing through the signal processing circuit (3), the laser signal is converted into a first harmonic electrical signal. At the same time, the gas components, solid components, and liquid components in the air environment in the vehicle interior and the corresponding vehicle body structure, objects, and personnel in the vehicle scatter the laser beam. The laser energy of the scattered and diffuse reflection is received synchronously by the photosensitive detector (2) at the same time, and the laser signal is converted into a second harmonic electric signal by the signal processing circuit (3). Finally, the first harmonic electric signal and the second harmonic electric signal are transmitted to the system control circuit (4). The system control circuit (4) and the TDLAS unit system of the system control circuit (4) perform calculation and identification on the received first harmonic electric signal and the second harmonic electric signal. The type and concentration of the air components in the vehicle compartment can be obtained according to the attenuation of the laser energy, and the harmful gas alarm can be issued through the system control circuit (4) and the vehicle's driving computer for the gas components that threaten the driving safety.

2. The automobile harmful gas detection system according to claim 1, characterized in that: The signal processing circuit (3) is a circuit system with a lock-in amplifier as its core.

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