Research Of Visible Light Communication In Smoke And Flame Detection

The occurrence of fire is unconscious and uncontrollable.If it cannot be detected in time and emergency remedial measures are taken,it will not only threaten human life and safety,but also cause irreversible harm to the natural environment.The occurrence of fire is inevitable,but in the early stage of fire,it can be detected by some real-time and effective method,so that people can find the fire in time and extinguish it quickly,and reduce the loss of fire to people’s safety and property.Therefore,timely detection of fires and effective control of fire generation and remediation play a vital role in ensuring personal safety and social ecological civilization.At present,traditional smoke detectors can no longer detect and prevent fires quickly,and people have higher and higher requirements for fire warning.With the development of computer technology and wireless communication technology,smoke video detection and Wi Fi detection smoke technology have been popularized and applied because of their intelligence and applicability.However,when a fire occurs,the shape,color,and size of smoke and flames are random,and the signal will also be interfered,resulting in low detection accuracy and efficiency based on smoke and flame,and the development of industrialization based on smoke detection is not perfect.Some researchers have also proposed a smoke detection technology based on deep learning,which improves the smoke detection rate to a certain extent,but the network parameters have limitations.VLC uses visible light as the transmitting terminal for information transmission,and is an emerging technology that can realize communication in a short distance.While realizing lighting,wireless communication can be carried out at the same time.Visible light communication technology has the advantages of anti-electromagnetic interference,energy saving,high efficiency,and environmental protection.At the same time as the research on visible light communication,people also hope to expand the application range of visible light communication,use effective visible light methods for sensing systems,and increase the application potential of visible light communication.Therefore,this paper proposes a method to detect the concentration of smoke,the presence or absence of flames and the location of the flame using visible light communication methods to solve the problems of the current fire smoke detection methods.The main work of this paper includes the following aspects:1)First,explain the serious fire problems in contemporary society and the need to improve smoke and flame detection technology,and summarize the basic content,detection principles and existing problems around traditional smoke detection and flame detection methods.A method for sensing smoke and flame based on the visible light communication method is proposed.From this,the visible light communication technology is introduced,and the advantages and necessity of the application of the visible light communication technology in scenes such as positioning are analyzed.2)The use of visible light communication methods to achieve smoke and flame detection needs to ensure that the visible light communication link can exert its maximum value.In response to this problem,the visible light communication system is introduced in detail,and the basic characteristics and working principles of the light emitting diode at the transmitting end and the photodetector at the receiving end are introduced in detail,and the nonlinear problem in the visible light communication link is pointed out.3)In view of the nonlinear problem of visible light communication,the visible light communication link is further optimized.The influence of the nonlinearity of light-emitting diodes on the visible light communication link and the influence of different receiving components on the visible light communication link are studied;due to the Lambertian characteristics of the LED light source,the distribution in the free space is different,and the LED-based Lambertian Under the model,the visible light communication receiving end accepts the study of the effective area problem to ensure that the received data is valid when the visible light information is transmitted.4)A scheme of using visible light communication method to realize smoke detection is proposed.When the analysis of the characteristics of the visible light communication link is relatively complete,the visible light communication method is applied to smoke detection.By introducing in the visible light transmission channel Smoke,analyze the influence of smoke concentration on the transmission of visible light communication information to realize smoke detection.Because smoke has a certain shielding effect on visible light,the signal received by the receiving end will be attenuated,and the amount of attenuation is closely related to the amount and distribution of smoke.By testing the attenuation of visible light information transmission under monochromatic red,blue and white light LEDs of different powers,it is further confirmed that the use of visible light communication methods has the potential for smoke detection,and smoke detection can be realized in the future.5)A method for detecting the presence and location of flames using visible light communication methods is proposed.By introducing a flame in a free space,the signal received at the receiving end will be attenuated to varying degrees due to the occlusion of the flame.The attenuation is related to the position and shape of the flame,and the perception of the flame position can be completed.Tests have further confirmed that the use of visible light communication methods can complete the presence or absence of flame,position and shape perception.In the future,indoor flame detection can be realized,and at the same time of information transmission,fire warning can be given.