Research And Application Of Blind Assist System Based On Sparse Ultrasonic Phased Array Technology

According to the latest statistics released by WHO,the number of visually impaired people in the world is up to 200 million,of which the total number of blind people is about 80 million,and the number of people who suffer from over 8 million is increasing continuously every year.At present,the blind set traffic to a certain extent can help the blind travel,but still there is a big security risk.In order to better help blind people to travel and improve the safety of blind people,it is necessary to detect and locate blind people's forward space obstacles.Therefore,on the basis of the blind system and the sparse ultrasonic phased array technology,this paper studies the blind aid system based on the sparse ultrasonic phased array technology.The research contents include:1.Started from the sound field characteristics of single circular piezoelectric ultrasonic transducer and the principle of ultrasonic phased array technology,the basic principle of two-dimensional ultrasonic phased array and the ultrasonic phased array beamforming technology are studied and analyzed,providing a theoretical basis for the design of blind assistance system.2.A two-dimensional ultrasonic phased array sound field model is set up,and the design of the phased array array and receiving array is carried out.The parameters of different array elements,array elements and center distance between elements are deeply simulated and analyzed.The 6*6 two-dimensional equidistant emission array and 3*3 two-dimensional equidistant receiving array are obtained.3.On the basis of two-dimensional isometric ultrasonic phased array,genetic algorithm is used to optimize the design of two-dimensional sparse ultrasonic phased array.In order to minimize the relative peak sidelobe of the array as the objective function,genetic algorithm is used to optimize the structure of two-dimensional sparse ultrasonic transceiver array,and the genetic algorithm is optimized by genetic algorithm two.The performance of the sparse ultrasound array is good,which meets the needs of the blind system.4.Completed the design and production of the blind system based on the sparse ultrasonic phased array technology.The delay of different transmission channel driving signals and the delay superposition of different receiving channel signals are realized based on the FPGA device,and the ultrasonic beam forming is effectively realized.5.The performance test and application experiment of sparse ultrasonic phased array aided blind system are carried out.Through the test of obstacle detection and positioning performance test,it shows that the system can realize forward space obstacle detection and spatial location,and the application research experiment shows that the blind system can realize the detection of the common obstacles in the forward direction and basically meet the daily travel safety requirements of the blind.The blind aid system based on sparse ultrasonic phased array technology is of great practical significance and value for expanding the living space of the blind and improving the quality of life of the blind.