An air suspension-based optical path spectrum detection method and detection system

Abstract

The application discloses an optical road spectrum detection method based on air suspension, which comprises the following steps: introducing reflected light through a light hole, calculating and correcting the reflection coefficient; adjusting the SPR resonance angle through an SPR sensor, calculating the change relationship between the phase difference of two components p and s of polarized light and the refractive index of gas and the phase response value; calculating the refractive index of gas according to the phase difference between the phase response of the SPR resonance angle and the phase response of the original phase angle; analyzing the road spectrum elevation information at a certain signal moment, and delimiting the road spectrum of single air suspension; integrating multiple road spectrums, and combining multiple road spectrum output modes. The application utilizes the air cavity in the original vehicle air suspension, the air port originally used for adjusting the suspension height, the light path entrance at the bottom of the suspension and the semi-transparent and semi-reflective lens to coordinate and cooperate. Through specific light transmission path design, the refraction of light is calculated, the air compression characteristics in the air suspension are obtained, and the road spectrum is drawn by comprehensively considering the vibration of the front wheel vehicle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicle environment perception detection, and particularly relates to an optical road spectrum detection method and system based on air suspension. BACKGROUND

[0002] The current related automobile spectrum detection method and system are designed by using binocular cameras and laser radars, and are currently equipped on high-grade or high-performance automobiles, but the main application scene thereof is identification of road features. After a vehicle identifies a corresponding road surface, a suspension, an automatic driving system, an ESC system, a torque control system, etc. perform corresponding strategies to ensure that the vehicle can be more comfortable and safe in driving or to perform front judgment of safety of automatic driving under corresponding road conditions.

[0003] The current technical solution is strongly dependent on binocular cameras or laser radars for scanning a road surface, and has obvious cost and design defects. The main manifestations are as follows:

[0004] 1. The binocular cameras or laser radars are currently redundant for actual needs of vehicles and are incompatible with current strict cost requirements. Generally, the binocular cameras or laser radars are used in conjunction with other high-level functions, and the use range is greatly limited.

[0005] 2. For a road spectrum identification system based on binocular cameras or laser radars, because the binocular cameras or laser radars mainly serve the function of automatic driving, the installation angle and detection range thereof are more inclined to be flat to identify target objects in front of driving, and the road spectrum identification function is more inclined to identify the ground. The contradiction between the two functions inevitably leads to selection of the function. SUMMARY

[0006] The present application aims to provide an optical road spectrum detection method and system based on air suspension, which utilizes an air cavity in an original air suspension of a vehicle, utilizes an air port in the air suspension for adjusting a suspension height, and utilizes a light path entrance at a bottom of the suspension and a semi-transparent and semi-reflective lens at a top end of the suspension to coordinate and cooperate. By specific light transmission path design, refraction of light is calculated, air compression characteristics in the air suspension are obtained, a road vibration condition is finally obtained, and road spectrum is drawn by comprehensively considering a front wheel vehicle vibration condition.

[0007] To solve the above technical problems, the technical solution of the present application is as follows: an optical road spectrum detection method based on air suspension, applied to an optical road spectrum detection system based on air suspension. The system comprises an air suspension system, a central controller, a CAN bus, and a light transmission hole. A polarizer, an air cavity, a total reflection lens, a semi-transparent and semi-reflective lens, and an SPR sensor are arranged in the light transmission hole. The method comprises the following steps:

[0008] The reflection coefficient is calculated and corrected by introducing reflected light through the light hole;

[0009] The relationship between the phase difference of the two components p and s of the polarized light and the change of the gas refractive index and the phase response value are calculated by adjusting the SPR resonance angle through the SPR sensor;

[0010] The gas refractive index is calculated according to the phase difference between the phase response of the SPR resonance angle and the phase response of the original phase angle;

[0011] The road spectrum elevation information at a certain signal moment is analyzed to demarcate a single air suspension road spectrum;

[0012] Multiple road spectra are integrated to combine multiple road spectrum output modes.

[0013] The method for calculating and correcting the reflection coefficient is:

[0014] The reflection coefficients of the two components p and s of the polarized light are obtained by Maxwell's equation as and

[0015]

[0016] The reflection coefficient is corrected as:

[0017]

[0018] Wherein, i=0,1; q=p,s;

[0019]

[0020] Wherein, The characteristic parameters of the two components p and s of the polarized light are different due to the different characteristics of p and s, and the algorithm representation of the characteristic parameters is also different.

[0021]

[0022] Wherein, k iz is the adjustment parameter of the SPR sensor, ω is the angular frequency of the light, θ is the original phase angle of the incident light measured by the SPR sensor, and ε0 is the reflection coefficient of the reference medium.

[0023] The method for calculating the relationship between the phase difference of the two components p and s of the polarized light and the change of the gas refractive index and the phase response value is:

[0024] The phase of component s is almost unchanged, and the phase of component p changes greatly near the SPR resonance angle. The relationship between the phase difference of components p and s and the change of the gas refractive index is linear, and the local slope S RI of the phase response is:

[0025]

[0026] wherein, is the phase difference of the two components p, s of the polarized light, n is the refractive index of the gas, d is the thickness of the transmission film of the SPR sensor, and the phase response reaches a maximum value when θ equals the SPR resonance angle.

[0027] The calculation method of the refractive index of the gas is:

[0028] The SPR sensor is adjusted so that the micro-vacuum cavity built in the SPR sensor is in a vacuum state, the refractive index of air under a standard state is compared, and the phase difference between the phase response of the SPR resonance angle and the phase response of the original phase angle of the phase change amount of this process is measured. The refractive index of the gas is calculated as:

[0029]

[0030] The specific method for delineating the road profile of a single air suspension is that the road profile elevation value h = n x k1 x k2 x k3 - h0.

[0031] Wherein, k1, k2, and k3 represent the temperature adjustment coefficient, the SPR sensor output adjustment compensation coefficient, and the attenuation and conversion compensation coefficient, respectively, and h0 is the standard height.

[0032] An array about the average value of the road profile elevation value h is set is {h T , h T-1 , h T-2 … h T-m}, which contains the road profile elevation values h of (m+1) signal periods.

[0033] An X-Y coordinate system is established with the center point of the vehicle suspension as the coordinate origin, and the height of the center point of the vehicle suspension is Then we have:

[0034]

[0035] wherein, is the array of all (x, y) grid points in the coordinate system at this moment, is the average value array of the standard height h0, x 中心 is the x-axis coordinate of the center point, and y 中心 is the y-axis coordinate of the center point.

[0036] The application also provides an air suspension-based optical road spectrum detection system, comprising an air suspension system, a central controller, a CAN bus and a light transmission hole; wherein the light transmission hole is internally provided with a polarizer, an air cavity, a total reflection lens, a semi-transmission semi-reflection lens and an SPR sensor.

[0037] The air suspension system is used for providing basic damping and shock absorption for a vehicle.

[0038] The CAN bus is used for providing the collected optical signals to the central controller for processing by a phase meter and algorithm processing of the SPR sensor.

[0039] The central controller is used for calculating and correcting the reflection coefficient, adjusting the SPR resonance angle, calculating the phase difference of the two components p and s of the polarized light with the change of the gas refractive index and the phase response value, calculating the gas refractive index according to the phase difference between the phase response of the SPR resonance angle and the phase response of the original phase angle, analyzing the road spectrum elevation information at a certain signal moment, and delimiting the road spectrum of a single air suspension.

[0040] The light transmission hole and the internally provided polarizer are used for filtering the sunlight of various frequencies and phases into incident light of a single frequency and introducing parallel light of a specific direction into the air cavity.

[0041] The air cavity is used as a darkroom to analyze the internal air density through the light propagation.

[0042] The total reflection lens and the semi-transmission semi-reflection lens are used for guiding the light to be reflected and refracted along a specific light path to ensure that the light path runs along a specific designed line.

[0043] The SPR sensor is used for intensity modulation, phase modulation, wavelength modulation and angle modulation, and the phase of the two components p and s of the polarized light of the sensor is adjusted to produce corresponding changes, thereby providing original data sources for the calculation of the refractive index.

[0044] The method for calculating and correcting the reflection coefficient is as follows:

[0045] The reflection coefficients of the two components p and s of the polarized light are obtained through Maxwell equation as follows: and

[0046]

[0047] The reflection coefficient is corrected as follows:

[0048]

[0049] wherein i=0, 1; q=p, s.

[0050]

[0051] wherein, are characteristic parameters of the two components p, s of the polarized light, and since the characteristics of p, s are different, the algorithms for representing the characteristic parameters are also different;

[0052]

[0053] wherein, k iz is an adjustment parameter of the SPR sensor, ω is the angular frequency of the light, θ is the original phase angle of the incident light measured by the SPR sensor, and ε0 is the reflection coefficient of the reference medium.

[0054] The method for calculating the relationship between the phase difference of the two components p, s of the polarized light and the change of the refractive index of the gas and the phase response value is:

[0055] The phase of component s is almost constant, the phase of component p changes greatly near the SPR resonance angle, the relationship between the phase difference of components p, s and the change of the refractive index of the gas is linear, and the local slope S RI of the phase response is:

[0056]

[0057] In the formula, is the phase difference of the two components p, s of the polarized light, n is the refractive index of the gas, and d is the thickness of the transmission film of the SPR sensor. When θ is equal to the SPR resonance angle, the phase response reaches a maximum value.

[0058] The method for calculating the refractive index of the gas is:

[0059] The SPR sensor is adjusted so that the built-in micro-vacuum cavity of the SPR sensor is in a vacuum state. The phase difference between the phase response of the SPR resonance angle and the phase response of the original phase angle is compared with the refractive index of air under the standard state and the phase change amount of this process is measured. The refractive index of the gas is calculated as:

[0060]

[0061] The specific method for delineating the road profile of a single air suspension by analyzing the road profile elevation information at a certain signal moment is: road profile elevation value h = n × k1 × k2 × k3 - h0

[0062] wherein, k1, k2, and k3 respectively represent a temperature adjustment coefficient, an SPR sensor output adjustment compensation coefficient, and a decay and conversion compensation coefficient, and h0 is a standard height.

[0063] An array about the average value of the road profile elevation value h is set as {hT , h T-1 , h T-2 …h T-m}, the array contains (m+1) signal period of road spectrum elevation value h;

[0064] The X-Y coordinate system is established with the vehicle suspension center point as the coordinate origin, and the height of the vehicle suspension center point is Then, we have:

[0065]

[0066] In the formula, is the array of all (x, y) grid points in the coordinate system at this moment, is the average array of the standard height h0, x 中心 is the x-axis coordinate of the center point, and y 中心 is the y-axis coordinate of the center point.

[0067] Compared with the prior art, the present application has the following advantages:

[0068] Safety benefit: The present application can ensure the smooth extraction of road spectrum information by the systems such as road self-adaptation, magic carpet, vehicle stability control, etc., based on the optical road spectrum detection method of air suspension under various environmental conditions, thereby ensuring driving safety.

[0069] Economic benefit: Based on the road spectrum recognition, the execution mechanism air suspension is designed to complete the subsequent function, which saves cost without adding other equipment.

[0070] Enterprise benefit: The present application is simple and practical, suitable for all vehicle models, and can interact with various types of air suspension systems and operate modularly. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 is the flowchart of the embodiment of the present application;

[0072] Figure 2 is the structural schematic diagram of the system of the embodiment of the present application;

[0073] Figure 3 is the architectural schematic diagram of the system of the embodiment of the present application;

[0074] In the figure, 1 is a CAN bus, 2 is a SPR sensor, 3 is a first total reflection lens, 4 is a second total reflection lens, 5 is a semi-transparent semi-reflective lens, 6 is a light detector, 7 is a light hole and an embedded polarizer. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0076] The vehicle is provided with an air suspension system, and the suspension system is provided with a fixed support structure, and the near-ground side and the far-ground side have moderate fixed surfaces to receive incident light in a specific direction. The specific requirements are as shown in Figure 2

[0077] The air suspension system has up and down adjustment movement function, but also has relatively stable relative position unchanged structure design, which utilizes the relative position unchanged structure in the air suspension to design the transmission light path. According to the optical principle, the different density parameters of the air cavity are measured, and the algorithm is called multiple times to complete the multiple density correction. Finally, the road vibration condition is obtained, and the road spectrum is drawn by combining the front wheel vehicle vibration condition.

[0078] To achieve this purpose, an optical road spectrum detection method and technology based on air suspension are proposed.

[0079] Embodiment 1: This embodiment is the design of the system:

[0080] The scheme includes an air suspension system supporting the basic structure of the design of the present application, a central controller (with an optical road spectrum detection method and technology based on air suspension), a CAN bus 1, a light hole, a polarizing plate built-in in the light hole, an air cavity, a total reflection lens, a half-transmission half-reflection lens 5, an SPR sensor 2 and several other parts.

[0081] The air suspension system normally provides basic shock absorption and shock avoidance functions for the vehicle. In the present application, the air cavity and other structures are utilized to complete the design of the road spectrum recognition scheme, and the air cavity of the air suspension can be fully utilized to complete the design of the road spectrum recognition scheme. Finally, the integration control of the road spectrum recognition and the vehicle comfort control system is realized, and the function design relying on road spectrum recognition such as road condition self-adaptation is executed.

[0082] The whole vehicle CAN bus 1 is used to provide the collected optical signals to the central controller for phase meter processing in the central controller and algorithm processing of the signal collected by the SPR sensor 2;

[0083] The central controller (with an optical road spectrum detection method and technology based on air suspension) is used for 1) storage and calculation of the function algorithm of the present application; 2) storage of the phase meter module of the light; 3) storage of the algorithm program of normal other functions; ​

[0084] The light hole and the built-in polarizer in the light hole are used to filter the sunlight of various frequency phases into a single frequency, and parallel light of a specific direction is introduced into the air cavity;

[0085] The air cavity piece is used for height adjustment and shock absorption of the air suspension base, and in the application, it is used as a darkroom, and the internal air density is analyzed through light propagation;

[0086] The total reflection lens and the half-transmission half-reflection lens 5 are used to guide the light to reflect and refract according to a specific light path, so as to ensure that the light path runs according to a specific design line;

[0087] The SPR sensor 2 is a refractive index sensor. The SPR refractive index sensor can generally need to perform corner scanning or wavelength scanning through angle modulation or wavelength modulation such as intensity modulation, phase modulation, wavelength modulation and angle modulation. The phase difference between the p and s polarization components of the reference light is changed by adjusting the p and s polarization components of the outgoing light of the sensor, which provides the original data source for the phase difference of the late refractive index calculation.

[0088] The technical scheme structure of the scheme is: the air suspension near the ground side is fixed by opening a hole, so that natural light is introduced, parallel light with relatively consistent frequency is obtained through the polarizer, a gas refractive index sensor is built in the air cavity of the air suspension, and an air inlet and a valve are provided in the air cavity of the air suspension. The natural light source passes through the polarizer (filters a specific frequency), and can output a pair of linearly polarized light with a wavelength of about 630 nm and orthogonal to each other (the frequency band is moderate and is convenient for analysis and correction in the later stage). The light beam passing through the polarizer is divided into two beams after passing through a half-transmission half-reflection mirror, the reflected light is received by the light detector 6 port built in the air suspension as the original reference light, and is introduced into the central controller phase meter; the transmitted light is reflected by the first total reflection lens 3, then enters the upper part of the SPR sensor 2 through the light transmission surface of the mirror 2, and the angular drift of the sensor light is self-corrected. The light beam exits in the direction of parallel incident light after a series of reflections in the internal structure of the SPR sensor 2, is reflected by the total reflection mirror 2, is received by the other port of the photodetector, forms a measurement signal, and is sent into the central controller phase meter. When the air pressure state in the air cavity changes due to vehicle movement and vibration and becomes inconsistent with the external environment, the SPR sensor 2 adjusts the phase of the outgoing light, especially the p and s polarization components, to ensure that the p and s light is in a common light path state, effectively suppresses interference, calculates the refractive index of the gas to be measured, and then calculates the suspension vibration condition through the change of the air refractive index in the air cavity, and finally completes the description of the road spectrum.

[0089] Embodiment 2: This embodiment is a design of the method:

[0090] 1) Reflection light introduction and reflection coefficient correction

[0091] The reflection coefficients of p and s polarized light can be obtained from Maxwell equation as follows

[0092]

[0093] Reflection coefficient correction:

[0094] Where i = 0, 1; q = p, s

[0095]

[0096] Where are characteristic parameters of p and s polarized light, and the characteristic parameters are different due to the different characteristics of p and s polarized light.

[0097]

[0098] k iz is an adjustment parameter of the SPR sensor 2, ω in the formula is the angular frequency of light, the original phase angle of the incident light measured by the SPR sensor 2 is θ, and ε0 is the reflection coefficient of the reference medium.

[0099] 2) SPR sensor 2 adjustment processing

[0100] Since the phase of the s polarized component is basically unchanged, and the phase of the p polarized component changes greatly near the SPR resonance angle. When the refractive index of the gas in the air cavity changes due to road vibration and compression and stretching, the p and s component curves are basically unchanged in shape and are translated, and the resonance angle changes. Further, the phase difference of the reflected light p and s components with the change of the refractive index of the gas can be calculated, and the phase difference of the reflected light p and s components and the change of the refractive index of the gas can be regarded as a linear relationship. The local slope of the defined phase response is

[0101]

[0102] In the formula is the phase difference of the reflected light p and s components, n is the refractive index of the gas, d is the transmission film thickness of the SPR sensor 2, and θ is the incident angle. The incident angle, S RI is approximately constant, and when the incident angle is equal to the resonance angle, the phase response reaches a maximum value.

[0103] 3) Refractive index calculation

[0104] Adjusting SPR sensor 2 to bring its built-in micro-vacuum cavity into a vacuum state, comparing the air refractive index under standard conditions, and measuring the phase change during this process, i.e., the phase difference between the phase responsivity of the SPR resonance angle and the phase responsivity of the original phase angle. The refractive index of the gas was calculated:

[0105]

[0106] The measurement accuracy of this method can reach 5×10⁻⁶. -6 The magnitude of the difference greatly facilitates the depiction of road maps.

[0107] 4) Delineation of a single suspended road surface

[0108] The road spectrum elevation value h = n × k1 × k2 × k3 - h0, where k1, k2, and k3 represent the temperature adjustment coefficient, the SPR sensor 2 output adjustment compensation coefficient, and the attenuation and conversion compensation coefficient, respectively; h0 is the standard height. This yields the road spectrum elevation information at a specific signal moment. This is recorded as hT, and an array is set. For {h T h T-1 h T-2 …h T-19 The average of 20 signal periods is used for merging and processing, especially for signals with large fluctuations. The values ​​are smoothed. The real-time values ​​are... Output the value.

[0109] Delineation of regional road network

[0110] Establish an XY coordinate system with the vehicle suspension center point as the origin, and the height of the vehicle suspension center point is... Then we have:

[0111]

[0112] Obtain single road spectrum elevation information in the vehicle coordinate system

[0113] (The same applies to the second to fourth air suspension systems) Road spectrum delineation is performed.

[0114] 5) Mode differentiation of multi-path spectrum

[0115] Based on the vehicle or customer's selected functional mode, multiple output modes can be combined. 1) Primarily providing full-spectrum output for controllable and autonomous driving functions. And merge them into the same coordinate system. 2) Primarily for full road spectrum output for comfort functions. Output They are merged into the same coordinate system, and a central controller is provided for calculation, and output adjustment commands for the rear suspension according to the corresponding functional logic.

[0116] It is to be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading the above description. The scope of the application should therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with their full scope of equivalents. The disclosure of all articles and references referred to herein are incorporated by reference in their entirety.

Claims

1. A method for optical road spectrum detection based on air suspension, characterized in that, An optical road spectrum detection system based on air suspension is applied. This system includes an air suspension system, a central controller, a CAN bus, and a light-transmitting aperture. The light-transmitting aperture houses a polarizer, an air cavity, a total internal reflection lens, a semi-transparent and semi-reflective lens, and an SPR sensor. The method includes the following steps: Reflected light is introduced through a light aperture, the reflection coefficient is calculated and corrected; By adjusting the SPR resonance angle using an SPR sensor, the relationship between the phase difference of the two polarized light components p and s and the phase responsivity value as a function of the gas refractive index can be calculated. The gas refractive index is calculated based on the phase difference between the phase responsivity of the SPR resonance angle and the phase responsivity of the original phase angle. Analyze the road spectrum elevation information at a certain signal moment to delineate the road spectrum of a single air suspension; It integrates multiple road spectrum sets and combines various road spectrum output modes.

2. The optical path spectrum detection method based on air suspension according to claim 1, characterized in that, The method for calculating and correcting the reflection coefficient is as follows: The reflection coefficients of the two components p and s of polarized light are obtained from Maxwell's equations as follows: and Correct the reflection coefficient: Where i = 0, 1; q = p, s; in, These are the characteristic parameters of the two polarized light components p and s, respectively. Since p and s have different characteristics, their characteristic parameter algorithms are also different. Where, k iz Here, ω is the adjustment parameter of the SPR sensor, θ is the angular frequency of the light, θ is the original phase angle of the incident light measured by the SPR sensor, and ε0 is the reflection coefficient of the reference medium.

3. The optical path spectrum detection method based on air suspension according to claim 2, characterized in that, The method for calculating the relationship between the phase difference of the two polarized light components p and s as a function of the gas refractive index and the phase responsivity value is as follows: The phase of component s remains almost constant, while the phase of component p changes significantly near the SPR resonance angle. The phase difference between components p and s is linearly related to the change in the gas refractive index. The local slope S of the phase responsivity is... RI for: In the formula, θ represents the phase difference between the two polarized light components p and s, n is the refractive index of the gas, and d is the thickness of the transmission film of the SPR sensor. When θ equals the SPR resonance angle, the phase responsivity reaches its maximum value.

4. The optical path spectrum detection method based on air suspension according to claim 3, characterized in that, The method for calculating the refractive index of a gas is as follows: The SPR sensor is adjusted to bring its built-in micro-vacuum cavity into a vacuum state. The refractive index of air under standard conditions is compared, and the phase change during this process is measured. This phase difference is calculated between the phase responsivity of the SPR resonance angle and the phase responsivity of the original phase angle. The refractive index of the gas was calculated:

5. The optical path spectrum detection method based on air suspension according to claim 4, characterized in that, The specific method for analyzing the road spectrum elevation information at a certain signal moment and delineating the road spectrum of a single air suspension is as follows: Road spectrum elevation value h = n × k1 × k2 × k3 - h0 Where k1, k2, and k3 represent the temperature adjustment coefficient, the SPR sensor output adjustment compensation coefficient, the attenuation and conversion compensation coefficient, and h0 is the standard height, respectively. Set an array for the mean h-values ​​of the road spectrum elevation. For {h T h T-1 h T-2 …h T-m The array contains the road spectrum elevation values ​​h for (m+1) signal periods; Establish an XY coordinate system with the vehicle suspension center point as the origin, and the height of the vehicle suspension center point is... Then we have: In the formula, This is an array of all (x, y) grid points in the coordinate system at that moment. For the average array of standard height h0, x 中心 Let x be the x-coordinate of the center point, y be the y-coordinate of the center point 中心 The y-axis coordinate of the center point.

6. A detection system using the air-suspended optical path spectrum detection method as described in claim 1, characterized in that, It includes an air suspension system, a central controller, a CAN bus, and a light-transmitting aperture; the light-transmitting aperture contains a polarizer, an air cavity, a total internal reflection lens, a semi-transparent and semi-reflective lens, and an SPR sensor. Air suspension systems are used to provide basic shock absorption and damping functions for vehicles; The CAN bus is used to provide the collected optical signals to the central controller for processing by the phase meter and the algorithm processing of the signals collected by the SPR sensor in the central controller. The central controller is used to calculate and correct the reflection coefficient; adjust the SPR resonance angle to calculate the relationship between the phase difference of the two polarized light components p and s and the phase responsivity value as a function of the gas refractive index; calculate the gas refractive index based on the phase difference between the phase responsivity of the SPR resonance angle and the phase responsivity of the original phase angle; analyze the road spectrum elevation information at a certain signal moment to delineate the road spectrum of a single air suspension; and integrate multiple road spectra to combine various road spectrum output modes. The light-passing aperture and built-in polarizer are used to filter sunlight of various frequencies and phases into incident light of a single frequency, and to introduce parallel light rays of a specific direction into the air cavity. An air cavity, acting as a darkroom, allows for the analysis of internal air density through the propagation of light. Total internal reflection lenses and semi-transparent semi-reflective lenses are used to guide light to reflect and refract along a specific optical path to ensure that the optical path operates according to a specific design. SPR sensors are used for intensity modulation, phase modulation, wavelength modulation, and angle modulation. By adjusting the phases of the two polarized light components p and s, the sensor produces corresponding changes, providing the raw data source for refractive index calculation.

7. The detection system according to claim 6, characterized in that, The method for calculating and correcting the reflection coefficient is as follows: The reflection coefficients of the two components p and s of polarized light are obtained from Maxwell's equations as follows: and Correct the reflection coefficient: Where i = 0, 1; q = p, s; in, These are the characteristic parameters of the two polarized light components p and s, respectively. Since p and s have different characteristics, their characteristic parameter algorithms are also different. Where, k iz Here, ω is the adjustment parameter of the SPR sensor, θ is the angular frequency of the light, θ is the original phase angle of the incident light measured by the SPR sensor, and ε0 is the reflection coefficient of the reference medium.

8. The detection system according to claim 7, characterized in that, The method for calculating the relationship between the phase difference of the two polarized light components p and s as a function of the gas refractive index and the phase responsivity value is as follows: The phase of component s remains almost constant, while the phase of component p changes significantly near the SPR resonance angle. The phase difference between components p and s is linearly related to the change in the gas refractive index. The local slope S of the phase responsivity is... RI for: In the formula, θ represents the phase difference between the two polarized light components p and s, n is the refractive index of the gas, and d is the thickness of the transmission film of the SPR sensor. When θ equals the SPR resonance angle, the phase responsivity reaches its maximum value.

9. The detection system according to claim 8, characterized in that, The method for calculating the refractive index of a gas is as follows: The SPR sensor is adjusted to bring its built-in micro-vacuum cavity into a vacuum state. The refractive index of air under standard conditions is compared, and the phase change during this process is measured. This phase difference is calculated between the phase responsivity of the SPR resonance angle and the phase responsivity of the original phase angle. The refractive index of the gas was calculated:

10. The detection system according to claim 9, characterized in that, The specific method for analyzing the road spectrum elevation information at a certain signal moment and delineating the road spectrum of a single air suspension is as follows: Road spectrum elevation value h = n × k1 × k2 × k3 - h0 Where k1, k2, and k3 represent the temperature adjustment coefficient, the SPR sensor output adjustment compensation coefficient, the attenuation and conversion compensation coefficient, and h0 is the standard height, respectively. Set an array for the mean h-values ​​of the road spectrum elevation. For {h T h T-1 h T-2 …h T-m The array contains the road spectrum elevation values ​​h for (m+1) signal periods; Establish an XY coordinate system with the vehicle suspension center point as the origin, and the height of the vehicle suspension center point is... Then we have: In the formula, This is an array of all (x, y) grid points in the coordinate system at that moment. For the average array of standard height h0, x 中心 Let x be the x-coordinate of the center point, y be the y-coordinate of the center point 中心 The y-axis coordinate of the center point.

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