Automobile headlamp detection device and detection method thereof

Abstract

A kind of automobile headlamp detection device and its detection method, including shell, the front end of shell is provided with light chamber, main sampling channel is provided in light chamber by silicon photocell, the rear end of shell is provided with measurement circuit, light chamber is also provided with auxiliary sampling channel.This automobile headlamp detection device is based on the measurement of light of silicon photocell, installs an auxiliary measurement sensor, forms auxiliary channel, carries out compensation to silicon photocell by the measurement data of auxiliary channel, can accurately measure halogen lamp, neon lamp and LED lamp, to replace CMOS measurement mode greatly reduces cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile lamp detection, and particularly relates to an automobile headlamp detection device and a detection method thereof. BACKGROUND

[0002] Motor vehicle headlamp detection has always been an important part of motor safety performance detection. With the rapid development of motor vehicle technology, the motor vehicle headlamp detection method is also changing. From the original silicon photocell technology to the later COMS camera image analysis technology, each has its own shortcomings. In the current national standard, the standard light source used is a halogen lamp, and there is no standard light source for xenon lamps and LED lamps.

[0003] From Figure 1 and Figure 2 The spectral diagram can be seen that the silicon photocell is not accurate for measuring LED lamps and xenon lamps, so the CMOS camera appears to take a picture of the light image, and then the light intensity is calculated through the gray scale of the image.

[0004] The spectral characteristics of CMOS are analyzed below. The spectral response characteristics and quantum efficiency of the CMOS camera, the spectral response range of the CMOS camera imaging device, is determined by the material of the photosensitive surface. The intrinsic silicon spectral response range is also between 400-1100 nm.

[0005] In fact, the spectral performance and quantum efficiency of the CMOS imaging device are both dependent on its image sensing unit (photodiode). The light response characteristics and quantum efficiency of the photodiode are affected by factors such as device surface light reflection, light interference, light transmittance of the surface layer, and photoelectron recombination. Generally, the quantum efficiency is less than 100%.

[0006] In addition, the above-mentioned influences vary with wavelength, so the quantum efficiency also changes with wavelength. The quantum efficiency at a wavelength of 400 nm is about 50%, the quantum efficiency at a wavelength of about 700 nm reaches a peak of about 70%, and the quantum efficiency at a wavelength of 1000 nm is only about 8%.

[0007] It can be seen that the visible light wavelength range is between 400 and 700 nm, and the spectral characteristics of the three types of automobile lamps are relatively large in this interval, except that the halogen lamp is close to a linear relationship. The LED and xenon lamps are non-linear jumps. For such non-linearity, it is difficult to accurately calibrate through a standard light source.

[0008] The measurement of halogen lamp by silicon photocell is very accurate, but with the development of automobile, LED lamp and xenon lamp gradually occupy a large market, the silicon photocell measurement method is naturally eliminated, even as some low-end market products, become a decoration. CMOS can adapt to LED and xenon lamp, although it cannot accurately measure the light intensity of LED and xenon lamp, as a basic judgment, it can meet the current market demand, but there is a disadvantage that the system is complex, and the price is much higher than that of silicon photocell measurement mode. Generally, repair shops are reluctant to purchase, and many times the repair of automobile light is judged by experience and naked eye observation. SUMMARY

[0009] The purpose of the present application is to provide a kind of automobile headlamp detection device and its detection method, which is used to solve the above problems, and the silicon photocell is compensated by the measurement data of auxiliary channel, so as to replace CMOS measurement mode and greatly reduce the cost.

[0010] The technical scheme adopted by the present application to solve the technical problems is:

[0011] A kind of automobile headlamp detection device, including shell, the front end of the shell is provided with light chamber, the main sampling channel is provided in the light chamber and is composed of silicon photocell, the rear end of the shell is provided with measuring circuit, and the light chamber is also provided with auxiliary sampling channel.

[0012] Further, the auxiliary sampling channel is composed of selenium photocell.

[0013] Further, the main sampling channel is provided with first filter, and the front end of the auxiliary sampling channel is provided with second filter.

[0014] Further, the first filter only passes through 400nm-600nm wavelength light, and the second filter only passes through 530nm-570nm wavelength light.

[0015] A kind of automobile headlamp detection method, using the above automobile headlamp detection device,

[0016] Before application, the amplification of main sampling channel and auxiliary sampling channel is set, the signal obtained by main sampling channel is amplified, then is converted into digital quantity by AD acquisition, and then is calibrated by standard light source, in addition, an auxiliary sampling channel is configured, the signal obtained by auxiliary sampling channel is also amplified, then is converted into digital quantity by AD acquisition, and then is calibrated by standard light source, so that the digital quantity of main sampling channel and auxiliary sampling channel is equal, and the amplification of main sampling channel and auxiliary sampling channel is obtained.

[0017] The compensation coefficient of the xenon lamp and the LED lamp is set, an illuminometer is selected, several xenon headlamps and LED headlamps are randomly selected, and are irradiated to the automobile headlamp detection device and the illuminometer, the values of the main sampling channel and the auxiliary sampling channel are compensated according to the difference between the values and the data of the illuminometer, the values after compensation are close to the values of the illuminometer through multiple compensation of multiple groups of xenon headlamps and LED headlamps, the compensation coefficient of the xenon lamp and the LED lamp is obtained, and is recorded;

[0018] When applied, the automobile headlamp is irradiated to the automobile headlamp detection device to obtain the light intensity of the automobile headlamp.

[0019] Further, the auxiliary sampling channel adopts a selenium photocell, a filter that only passes light of 400nm-600nm wavelength is arranged at the front end of the main sampling channel, and a filter that only passes light of 530nm-570nm wavelength is arranged at the front end of the auxiliary sampling channel.

[0020] The automobile headlamp detection device of the present application has the following advantages:

[0021] By adopting the above technical scheme, the automobile headlamp detection device of the present application can accurately measure halogen lamps, neon lamps and LED lamps by installing an auxiliary measurement sensor in the silicon photocell to form an auxiliary channel, and compensating the silicon photocell according to the measurement data of the auxiliary channel, thereby replacing the CMOS measurement method and greatly reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] The present application will be further described below in combination with the drawings and examples.

[0023] Figure 1 is a common spectrum characteristic curve diagram of the three kinds of automobile headlamps;

[0024] Figure 2 is a spectrum characteristic curve diagram of a silicon photocell and a selenium photocell;

[0025] Figure 3 is a structural schematic diagram of the automobile headlamp detection device of the present application;

[0026] Figure 4 is a hardware block diagram of the automobile headlamp detection device of the present application;

[0027] Figure 5 is a detection circuit diagram of the automobile headlamp detection device of the present application.

[0028] The drawings show that: 1, the shell; 2, the light collecting chamber; 3, the main sampling channel; 4, the measurement circuit; 5, the auxiliary sampling channel; 6, the first filter; 7, the second filter; 8, the rechargeable battery; 9, the liquid crystal operation screen. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0030] like Figures 3-5 As shown, an automotive headlight detection device includes a housing 1, a light-collecting chamber 2 at the front end of the housing 1, a main sampling channel 3 composed of silicon photocells inside the light-collecting chamber 2, a measurement circuit 4 at the rear end of the housing 1, and an auxiliary sampling channel 5 inside the light-collecting chamber 2.

[0031] This device is equipped with a silicon photodiode as the main measurement unit, and can be fitted with a first filter 6 to filter out all wavelengths outside 400nm to 600nm, retaining the visible light range. In addition, this device is equipped with a selenium photodiode or optical glass with a second filter 7 to ensure that the spectrum with a peak of 550nm can pass through as an auxiliary unit.

[0032] The silicon photovoltaic cell serves as the main sampling channel 3. After filtering out wavelengths outside 400nm to 600nm, the signal is amplified and then converted into a digital signal via an analog-to-digital converter. It is then calibrated using a standard light source. Since the standard light source is currently a halogen lamp, the silicon photovoltaic cell exhibits excellent linearity in this wavelength range. The calibrated instrument can accurately measure all halogen lamp lights.

[0033] The system is additionally configured with a selenium photocell or optical glass that ensures the 550nm peak spectrum can pass through as auxiliary sampling channel 5. We also amplify the signal, convert the analog signal to digital using an AD converter, and calibrate auxiliary sampling channel 5 using a standard light source. After calibration, our next step is to set the compensation coefficients for xenon and LED lamps. If the lamp being measured is a halogen lamp, the values ​​of auxiliary sampling channel 5 and main sampling channel 3 should be close. However, for xenon and LED lamps, auxiliary sampling channel 5 specifically amplifies the 550nm peak spectrum. According to automotive lighting characteristics, 550nm is the brightest point for xenon and LED lamps. Therefore, the value of auxiliary sampling channel 5 should be greater than the value of main sampling channel 3. Currently, there are no standard lamps for xenon and LED headlights. We can use a lux meter, randomly selecting several xenon headlights to illuminate the measuring device, and using the values ​​collected by main sampling channel 3 and auxiliary sampling channel 5 and the lux meter data as a basis for difference compensation. The compensated value should be close to the value measured by the illuminance meter. Through multiple compensations for xenon headlights and LED lights, the xenon headlights and LED headlights of a car can be measured more accurately.

[0034] Two sampling signals are amplified by signal amplifiers respectively, because the short-circuit current of the photocell is most linear, we must take a small value for the load resistance of the photocell. Then the obtained mv signals are amplified. The amplified signals become digital quantities through AD acquisition. Because two sampling channels pass through different spectral filters, the main sampling channel 3 filters less light sources, and the amplification multiple should be smaller. The auxiliary sampling channel 5 filters more light sources, and the spectral range is small, so the amplification multiple needs to be larger to ensure that the two channels display the same value.

[0035] The measurement circuit 4 obtains the digital quantity signals collected by the two groups of sensors, and we can correspond the digital quantity to the light intensity by standard light sources. This process is called calibration. Because the standard light source is a halogen lamp, we can calibrate the main sampling channel 3 and the auxiliary sampling channel 5. When calibrating, the distance between the sampling head and the light source should be fixed, which can be set to 1 meter. After calibration, the detection corresponding to the halogen lamp should be correct.

[0036] Corresponding to the xenon lamp and the LED lamp, we need to use a standard luxmeter. Because there is no xenon lamp and LED lamp in the current standard light source, we use the standard luxmeter as a reference. According to the conversion method of "light intensity = illumination x distance square", our instrument is equipped with a 1-meter telescopic guide rod, which ensures that the distance between the sampling sensor and the light source is 1 meter. At this time, we select different xenon light sources to irradiate the two sampling photocells, and the displayed values will certainly be different. The amplification multiple of the main sampling channel 3 is not as large as that of the auxiliary sampling channel 5, which is corresponding to the small spectral range of the xenon lamp, so the value of the auxiliary sampling channel 5 will be greater than that of the main sampling channel 3. Then we use the luxmeter to convert the real light intensity of the light source. Follow the difference between the main and auxiliary channels, and the real light intensity, to perform interpolation algorithm. Ensure that different xenon lamps can be measured correctly. The same method is used for LED lamps.

[0037] Moreover, the automobile headlamp detection device is designed as a portable type, the device is equipped with a set of rechargeable battery 8 as a battery management system. The system sampling is graphical liquid crystal display, and a liquid crystal operation screen 9 is added to the surface of the shell 1, so that the humanized indication operation can be conveniently performed. The device is also equipped with serial communication and Bluetooth communication device, which is convenient for networking.

[0038] The above embodiments of the present application are not a limitation on the protection scope of the present application, and the embodiments of the present application are not limited to this. According to the above content of the present application, according to the ordinary technical knowledge and conventional means in the art, other various forms of modification, replacement or change of the above structure of the present application are made without departing from the above basic technical idea of the present application, which should fall within the protection scope of the present application.

Claims

1. A vehicle headlamp detection method applied to a vehicle headlamp detection device, characterized by, The automobile headlamp detection device comprises a shell, a light collecting chamber is arranged at the front end of the shell, a main sampling channel composed of a silicon photocell is arranged in the light collecting chamber, a measuring circuit is arranged at the rear end of the shell, and an auxiliary sampling channel is further arranged in the light collecting chamber. The auxiliary sampling channel is composed of a selenium photocell; and the automobile headlamp detection method comprises: Before application, the amplification multiples of the main sampling channel and the auxiliary sampling channel are set: the main sampling channel is calibrated by a standard light source, the signal obtained by the main sampling channel is amplified, and then is converted into a digital quantity by AD acquisition; in addition, an auxiliary sampling channel is configured, the auxiliary sampling channel is calibrated by a standard light source, the signal obtained by the auxiliary sampling channel is also amplified, and then is converted into a digital quantity by AD acquisition; the digital quantities obtained by the main sampling channel and the auxiliary sampling channel are equalized, and the amplification multiples of the main sampling channel and the auxiliary sampling channel are obtained; The compensation coefficients of the xenon lamp and the LED lamp are set: an illuminometer is selected, several xenon headlamps and LED headlamps are randomly selected, and are irradiated to the automobile headlamp detection device and the illuminometer; the values of the main sampling channel and the auxiliary sampling channel are compensated by difference based on the data of the illuminometer; the values after compensation are close to the values of the illuminometer through multiple compensations of multiple groups of xenon headlamps and LED headlamps, the compensation coefficients of the xenon lamp and the LED lamp are obtained, and are recorded; In application, the automobile headlamp is irradiated to the automobile headlamp detection device, and the light intensity of the automobile headlamp is obtained. The main sampling channel is provided with a first filter, and the front end of the auxiliary sampling channel is provided with a second filter. The first filter only passes light with a wavelength of 400nm-600nm, and the second filter only passes light with a wavelength of 530nm-570nm.

Images