Research Of Intelligent Lighting System Based On Brain Computer Interface

Brain-computer Interface system is the research focus of many disciplines in recent years,different from traditional brain information output channel,it is an entirely new way of human-computer interaction,through which the brain can directly interact with the outside world.In this paper,we study a kind of intelligent lighting system using brain-computer interface technology,the ultimate aim is to directly convey the human thinking tasks in the brain to control lighting,to most people who have perfect functions but part of the body function defects,will greatly improve their quality of life,convenient their daily life,and can save social resources,so this article have great important research value.The core to realize BCI is to find a way to represent the characteristic signal of brain,and brain electrical signal is comply with this requirement.The research of BCI at home and abroad based on different types of brain electric signal has received a lot of research results,this article uses the visual evoked potential as the target signal.Because the VEP does not need the user long-term training,the characteristic which can accept passively,is very suitable for the request of the system.In this paper,we first design a potential acquisition system to collect EEG signals from the skin of the user's head.Brain electrical signal is very weak and vulnerable to noise interference,it is inevitable to use the amplifier amplification signal if we want to faint brain electrical signal collection.According to the characteristics of the brain electrical signals,this paper selects the instrumentation amplifier AD620 as a amplification core of the whole acquisition system,and uses the original left ear drive circuit to improve the signal,the signal after amplification through the filter and secondary amplification processing,direct input to the control core of the AD conversion module.This article chooses STM32103 as the control core of the whole system,STM32103 has 12 precision AD conversion module,its excellent performance and small size can satisfy the requirements of the system.In the wireless transmission part,I use the ZIGBEE technology,node chip for CC2530,realized the function of a serial port pass-through,it can transmit the control information stable and reliable between nodes,and finally completed the function of wireless open luminaire.In addition,this article uses the c # language to write a PC software,to make the turn on and off the lights visual stimulation to the user,and make the brain electrical signals can be collected in binary format in the upper machine,in order to further analysis,the software designed especially for visual evoked potential experiment for a variety of functions,including stimulus duration,frequency,cumulative average,etc.,can according to the different feedback of subjects,change test parameters flexibly to achieve the switch between steady visual potential stimulus visual potential,in order to have a better experimental results.After the brain electrical signals were recorded,there was much noise,characteristic signal is usually submerged in a lot of noise,so we need to deal with the collected signal.At first,this paper uses the cumulative average method,combined with PC software in this function,make proper accumulative average process to the signals,greatly improve the SNR,and offer a lot of convenience for subsequent processing.Then make a further processing to the signal after cumulative average introducing the wavelet transform,after practice,choose db5 8 scale wavelet to decompose target signals,and according to the results,select one of the d5,d6,d7 layer detail signal reconstruction,through analysis,the signal after reconstruction can well reflect the characteristics of brain electrical signals.Figure 46 table 2 reference 117...