CN105158218A - Non-contact monitoring device and method for floating oil on water surface - Google Patents

Abstract

A non-contact water surface oil floating monitoring device, including ultraviolet wide-spectrum light source, filter, filter wheel, emitting lens, receiving lens, multi-spectral detector and control and signal processor, wherein the ultraviolet broad-spectrum The light source, optical filter and emitting lens form the emitting optical path, the receiving lens and the multi-spectral detector form the receiving optical path, the optical filter rotates under the drive of the optical filter wheel, the optical filter wheel, the ultraviolet The spectral light source and the multispectral detector are connected to the control and signal processor. The invention has the beneficial effects of adopting multi-spectral light sources and multi-spectral detectors, and minimizing the false alarm rate through two working modes; meanwhile, it has the advantages of low cost, non-contact and real-time monitoring. The invention also discloses a non-contact water surface oil slick monitoring method.

Description

A non-contact water surface oil slick monitoring device and method

technical field

The invention relates to a non-contact water surface oil slick monitoring device and method, belonging to the technical field of photoelectric sensors.

Background technique

With the development of human activities, various oil spill incidents on the water surface continue one after another. The oil spill will float on the water surface, which will not only bring huge economic losses to the society, but also bring immeasurable environmental and ecological impacts. Although there are various preparations to prevent oil spills on the water surface, due to the unpredictability and instantaneous nature of oil spills, how to determine the occurrence of oil spills in the first place is still the most effective way to prevent the spread of hazards.

Among the various oil slick monitoring technologies on the water surface, the most critical is to be able to detect the existence of the oil slick on the water surface at low cost, in real time, without contact, and with high reliability. Ultraviolet light-induced fluorescence is a highly sensitive non-contact method for detecting oil slicks on water surfaces. A short-wavelength light beam is emitted to the water surface. When there are oily substances containing polycyclic aromatic hydrocarbons on the water surface, it will excite fluorescence with a longer wavelength. The detection of oil slicks on the water surface can be realized through the detection of fluorescence.

Among the existing technologies for detecting oil slicks on water surfaces based on ultraviolet light-induced fluorescence, although the detection method using lidar has high sensitivity, the structure is very complicated and the cost is high, and it cannot be arranged at multiple fixed points for continuous monitoring , but also has the disadvantages of limited excitation wavelength and high detection false alarm rate.

Although laser-induced fluorescence and spectrometers are used to collect fluorescence continuous spectra for water surface oil slick monitoring, although it has good identification ability, it has the disadvantages of low sensitivity and high cost of spectrometers, and it is difficult to be widely promoted.

In recent years, there have been devices that use narrow-band UV LEDs as the excitation light source for oil slick detection on water surfaces. However, since the current high-power UV LEDs only have a wavelength of 365nm, the detection effect on heavy oil such as crude oil is better, and the effect on light oil detection is not good. And because the wavelength of the excitation light source is limited, there is only one detection band, so the false alarm rate is high, and it is difficult to distinguish other fluorescent substances floating on the water surface.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a non-contact water surface oil slick monitoring device and method, which has the advantages of low cost, non-contact, real-time monitoring, and low false alarm rate, can be placed at fixed points, and is suitable for a wide range promote.

Technical scheme of the present invention is:

A non-contact water surface oil floating monitoring device, including ultraviolet wide-spectrum light source, filter, filter wheel, emitting lens, receiving lens, multi-spectral detector and control and signal processor, wherein the ultraviolet broad-spectrum The light source, optical filter and emitting lens form the emitting optical path, the receiving lens and the multi-spectral detector form the receiving optical path, the optical filter rotates under the drive of the optical filter wheel, the optical filter wheel, the ultraviolet A spectral light source and a multispectral detector are connected to the control and signal processor.

The ultraviolet wide-spectrum light source emits wide-spectrum ultraviolet light. After passing through the filter, only the required spectral band passes through the wide-spectrum ultraviolet light beam, and then projected to the monitored water surface area through the emitting lens. The receiving lens receives the excited fluorescent signal and converges to multiple On the spectral detector, the controller controls the light source and detector synchronously, collects and processes the photodetector signal, and judges whether there is oil slick.

The spectral radiation of the ultraviolet broad-spectrum light source covers at least a 200-400nm spectral range, and the ultraviolet broad-spectrum light source is preferably a pulsed xenon lamp light source.

The optical filter includes a broadband optical filter with a passband of 200-400nm and a plurality of narrow-band optical filters with a passband of 200-400nm. In the warning mode, the filter is fixed at the position of 200-400nm, and in the judgment mode, the other filters are replaced sequentially.

The multi-spectral detector is a photodiode array coated with a narrow-band filter film on the photosensitive surface, and the passband covers the range of 400-700nm.

The emitting lens adopts a single lens capable of transmitting 200-400nm light, preferably a plano-convex fused silica lens. The distance projected to the water surface and the spot size are controlled by the selection of the focal length of the single lens.

The receiving lens adopts a single lens capable of transmitting 400-700nm light, preferably a plano-convex K9 glass lens. Converge the light in the spot area onto the photosensitive surface of the multispectral detector by selecting an appropriate single lens focal length.

The control and signal processor coordinate the work of the ultraviolet wide-spectrum light source, detector and filter wheel, including ultraviolet wide-spectrum light source drive, multi-spectral detector drive, filter wheel control, signal preprocessing, and spectral data processing ,External Interface. The control and signal processor realizes the acquisition of the fluorescence spectrum data of the oil slick through the synchronous control of the ultraviolet wide-spectrum light source, filter wheel, and multi-spectral detector, and further obtains the result of whether there is oil slick through data processing. The interface such as the wireless communication interface is transmitted to the upper computer.

A non-contact method for monitoring oil slicks on the water surface, using an ultraviolet wide-spectrum light source, the wide-spectrum light beam is filtered by an optical filter and then projected to the monitored water surface area by an emission lens, and excitation light sources of various spectra are obtained by changing the optical filter, thereby A variety of different fluorescence spectra are excited.

The excited fluorescence is received by a multispectral detector, and the presence of oil on the water surface is judged by analyzing the collected multispectral fluorescence information.

There are two working modes: early warning and judgment. In the early warning mode, select a broadband bandpass filter and keep it fixed when there is no fluorescent signal. When there is a fluorescent signal, use the judgment mode to replace multiple filters and collect different excitation light sources. Under the multi-spectral fluorescence signal, use multiple data to judge and reduce the false alarm rate.

The invention has the beneficial effects of adopting multi-spectral light sources and multi-spectral detectors, and minimizing the false alarm rate through two working modes; meanwhile, it has the advantages of low cost, non-contact and real-time monitoring.

Description of drawings

Fig. 1 is a schematic diagram of a non-contact surface oil floating monitoring device according to the present invention.

In the picture:

1 is a wide-spectrum light source, 2 is a filter, 3 is an emitting lens, 4 is an excitation light beam, 5 is the water surface to be measured, 6 is an excited fluorescent beam, 7 is a receiving lens, 8 is a multi-spectral detector, 9 is Control and signal processor, 10 is a filter wheel.

Figure 2 is the pass band curve of the filter film of the multispectral detector.

Figure 3 is a functional block diagram of the control and signal processor.

Figure 4 is a working flow diagram of the oil slick monitoring device on the water surface.

Detailed ways

The technical solution of the present invention is specifically described below in conjunction with the accompanying drawings. It should be pointed out that the technical solution of the present invention is not limited to the implementation described in the examples. Those skilled in the art refer to and learn from the content of the technical solution of the present invention. Improvements and designs made on the basis of the invention shall belong to the protection scope of the present invention.

As shown in Figures 1-4, a non-contact water surface oil slick monitoring device described in the embodiment of the present invention includes an ultraviolet wide-spectrum light source, a filter, a filter wheel, a transmitting lens, a receiving lens, a multispectral Detector and control and signal processor, wherein the ultraviolet wide-spectrum light source, optical filter and emitting lens form the emitting optical path, the receiving lens and the multi-spectral detector form the receiving optical path, and the optical filter is formed in the filter turning The wheel is driven to rotate, and the filter wheel, ultraviolet wide-spectrum light source and multi-spectrum detector are connected with the control and signal processor.

The ultraviolet wide-spectrum light source emits wide-spectrum ultraviolet light. After passing through the filter, only the required spectral band passes through the wide-spectrum ultraviolet light beam, and then projected to the monitored water surface area through the emitting lens. The receiving lens receives the excited fluorescent signal and converges to multiple On the spectral detector, the controller controls the light source and detector synchronously, collects and processes the photodetector signal, and judges whether there is oil slick.

The spectral radiation of the ultraviolet broad-spectrum light source covers at least a 200-400nm spectral range, and the ultraviolet broad-spectrum light source is preferably a pulsed xenon lamp light source.

The optical filter includes a broadband optical filter with a passband of 200-400nm and a plurality of narrow-band optical filters with a passband of 200-400nm. In the warning mode, the filter is fixed at the position of 200-400nm, and in the judgment mode, the other filters are replaced sequentially.

The multi-spectral detector is a photodiode array coated with a narrow-band filter film on the photosensitive surface, and the passband covers the range of 400-700nm.

The emitting lens adopts a single lens capable of transmitting 200-400nm light, preferably a plano-convex fused silica lens. The distance projected to the water surface and the spot size are controlled by the selection of the focal length of the single lens.

The receiving lens adopts a single lens capable of transmitting 400-700nm light, preferably a plano-convex K9 glass lens. Converge the light in the spot area onto the photosensitive surface of the multispectral detector by selecting an appropriate single lens focal length.

The control and signal processor coordinate the work of the ultraviolet wide-spectrum light source, detector and filter wheel, including ultraviolet wide-spectrum light source drive, multi-spectral detector drive, filter wheel control, signal preprocessing, and spectral data processing ,External Interface. The control and signal processor realizes the acquisition of the fluorescence spectrum data of the oil slick through the synchronous control of the ultraviolet wide-spectrum light source, filter wheel, and multi-spectral detector, and further obtains the result of whether there is oil slick through data processing. The interface such as the wireless communication interface is transmitted to the upper computer.

A non-contact method for monitoring oil slicks on the water surface, using an ultraviolet wide-spectrum light source, the wide-spectrum light beam is filtered by an optical filter and then projected to the monitored water surface area by an emission lens, and excitation light sources of various spectra are obtained by changing the optical filter, thereby A variety of different fluorescence spectra are excited.

The excited fluorescence is received by a multispectral detector, and the presence of oil on the water surface is judged by analyzing the collected multispectral fluorescence information.

There are two working modes: early warning and judgment. In the early warning mode, select a broadband bandpass filter and keep it fixed when there is no fluorescent signal. When there is a fluorescent signal, use the judgment mode to replace multiple filters and collect different excitation light sources. Under the multi-spectral fluorescence signal, use multiple data to judge and reduce the false alarm rate.

in:

60W pulsed xenon lamp is selected as the wide-spectrum light source;

A plurality of narrowband filters and a broadband filter are integrated on the filter wheel, among which, the passband range of the broadband filter is 200-400nm, and the narrowband filter is a subdivided bandpass between 200-400nm filter.

The emission lens has a diameter of 50mm and a focal length of 100mm. It is made of fused silica material and the passband is 200-400nm;

The receiving lens has a diameter of 50mm and a focal length of 100mm. It is made of K9 glass material and the passband is 400-700nm;

A multi-spectral photodiode array with 8 narrow-band channels is selected, and each channel only responds to optical signals in a specific wavelength range between 400 and 700 nm and converts them into electrical signals. The central wavelengths of the 8 narrowband channels are: 430nm, 460nm, 490nm, 515nm, 560nm, 615nm, 660nm, 695nm, and the bandwidth is 10nm.

The control and signal processor can use industrial-grade M3 ARM processor (such as STM32F103) as the control core, and the multi-spectral detector driver can use AD8615 to form a lock-in amplifier. The signal preprocessing part is mainly analog filtering and analog-to-digital conversion, and AD7798 can be used. External interface can choose RS485 or GPRS.

When the device works in the early warning mode, the filter wheel rotates at the broadband bandpass filter, and the light emitted by the light source passes through the broadband bandpass filter to obtain continuous excitation light between 200 and 400nm, and then is collected by the emission lens. After the light is irradiated on the water surface, the fluorescent signal generated by the stimulated emission of the water surface is converged by the receiving lens, and the multispectral photodiode array is controlled by the control and signal processor to obtain fluorescent signals in different spectral bands between 400 and 700nm. The signal processor processes the collected signal, and initially judges whether there is an oil film by comparing with the set threshold value. When the preliminary judgment result is that there is an oil film, the device enters the judgment mode.

When the device is working in the judgment mode, the filter wheel starts to rotate to replace different filters. Every time the filter rotates to a filter, the light emitted by the light source passes through the filter to obtain excitation light of a specific wavelength. After being converged by the transmitting lens, it is irradiated on the oil film on the water surface. The fluorescent signal generated by the excitation of the oil film is converged by the receiving lens, and then the control and signal processor controls the multispectral photodiode array to obtain fluorescent signals in different spectral bands between 400 and 700nm. . The control and signal processor sequentially controls the filter wheel to switch between different filters to obtain excitation light of different wavelengths, and at the same time controls the multispectral photodiode array to obtain the fluorescence spectrum excited by excitation light of corresponding wavelength. After the multi-spectral fluorescence signals excited by all excitation wavelengths are collected, the collected data forms a three-dimensional fluorescence spectrum (excitation wavelength, fluorescence wavelength, fluorescence intensity), and comprehensive processing such as spectrum matching is performed on the collected data to eliminate easily causing interference substances It can accurately judge whether there is an oil film on the water surface. Compared with the early warning mode, increasing the amount of collected information minimizes the misjudgment rate.

Claims (10)

1. a contactless oil slick monitoring device, comprise ultraviolet broad spectrum light source, optical filter, optical filter runner, launch camera lens, receive camera lens, multispectral sensing device and control and signal processor, it is characterized in that, wherein said ultraviolet broad spectrum light source, optical filter become to launch light path with transmitting mirror head group, described reception camera lens, multispectral sensing device composition receiving light path, described optical filter rotates under optical filter runner drives, and described optical filter runner, ultraviolet broad spectrum light source are connected with signal processor with described control with multispectral sensing device.

2. a kind of contactless oil slick monitoring device as claimed in claim 1, it is characterized in that, the spectral radiance of described ultraviolet broad spectrum light source at least covers 200 ~ 400nm spectral range, ultraviolet broad spectrum light source preferred pulse xenon source.

3. a kind of contactless oil slick monitoring device as claimed in claim 1, is characterized in that, described optical filter comprises a slice broad band pass filter that passband is 200 ~ 400nm and the passband multi-disc narrow band pass filter in 200 ~ 400nm scope.

4. a kind of contactless oil slick monitoring device as claimed in claim 1, is characterized in that, described multispectral sensing device is the photodiode array of light-sensitive surface plating narrow-band-filter film, and passband covers 400 ~ 700nm scope.

5. a kind of contactless oil slick monitoring device as claimed in claim 1, it is characterized in that, described transmitting camera lens adopts and through the simple lens of 200 ~ 400nm light, can be preferably plano-convex fused quartz lens, controls by the selection of simple lens focal length the Distance geometry spot size projecting the water surface.

6. a kind of contactless oil slick monitoring device as claimed in claim 1, it is characterized in that, described reception camera lens adopts can through the simple lens of 400 ~ 700nm light, being preferably plano-convex K9 glass lens, by selecting suitable simple lens focal length, the light of spot area being converged on multispectral sensing device light-sensitive surface.

7. a kind of contactless oil slick monitoring device as claimed in claim 1, it is characterized in that, described control and signal processor are coordinated ultraviolet broad spectrum light source, detector and optical filter runner and are worked, and comprise the driving of ultraviolet broad spectrum light source, the driving of multispectral sensing device, the control of optical filter runner, Signal Pretreatment, spectroscopic data process, external interface; Control with signal processor by the synchro control to ultraviolet broad spectrum light source, optical filter runner, multispectral sensing device, realize the acquisition of oil slick fluorescence data, the result whether having oil slick is drawn, by external interface as wireless communication interface is transferred to host computer further by data processing.

8. one kind uses the monitoring method of contactless oil slick monitoring device described in any one of claim 1 to 7, adopt ultraviolet broad spectrum light source, broad-spectrum beam projects monitored water-surface areas by transmitting camera lens after optical filter filters, obtain the excitation source of multiple spectrum by changing optical filter, thus inspire multiple different fluorescence spectrum.

9. monitoring method as claimed in claim 8, is characterized in that, fluorescence excitation adopts multispectral sensing device to receive, and judges the existence of water surface oil by analyzing the multispectral fluorescence information gathered.

10. monitoring method as claimed in claim 8, it is characterized in that, divide early warning and judge two kinds of mode of operations, under modes of warning, select broadband belt pass filter, keeping when there is no fluorescence signal fixing, when there is fluorescence signal, adopting judgment model, change multiple optical filter, gather the multispectral fluorescence signal under different excitation source, utilize multiple data to judge, reduce false alarm rate.