Development Of Living Object Detection Module For Electric Vehicle Wireless Charging System

With the rapid increase in the demand for electric vehicles,the demand for charging piles is also rising.Traditional wired charging methods have problems such as low space utilization,while wireless charging methods have better applicability and safety.However,the high-frequency magnetic field generated by the wireless charging system is harmful to the human body and other living objects,so living object detection has important research significance for the promotion and development of wireless charging technology for electric vehicles.This paper proposes a detection scheme that uses ultrasonic ranging to determine living objects.Through the analysis of the ultrasonic distance measurement principle and the working process of the ultrasonic probe,the ultrasonic transmitter and receiver circuit are designed.The transmitting circuit uses the mid-circle transformer to amplify the ultrasonic transmitting power and drives the integrated ultrasonic transducer to emit ultrasonic signals;the receiving circuit designs an amplifying and filtering circuit according to the characteristics of the ultrasonic echo.Ultrasonic distance measurement is greatly affected by temperature.The module adds a temperature sensor to calculate the propagation speed of ultrasonic waves and improve the accuracy of distance measurement.And on the basis of the original system electrical protection circuit,an air switch protection measure for live object detection is added.According to the requirements and characteristics of living object detection,this article relies on experimental results and theoretical analysis to determine the installation position and placement angle of the ultrasonic probe on the primary side of the wireless charging system.This program is based on the layout design of the ultrasonic probe,using the method of information fusion,and compiling related programs such as the probe measurement sequence and the determination of the living thing for how to distinguish the state of the living thing in the detection area.At the end of this paper,the designed ultrasonic live detection module is verified by related experiments.The results show that: when the electric vehicle is not charged,the detection blind zone is small and the detection accuracy is high;during the charging period of the electric vehicle,the detection blind zone increases,but it can still meet the testing requirements after parameter adjustment.Therefore,this scheme has certain engineering value and practical significance.