Research On Underwater Shape Detection Method Based On Active Electric Field And Electric Field Characteristics

Active electric field technology is a detecting technique using low-frequency and low-voltage electric fields.It is derived from the biomimetic study of weak electric fish.It overcomes the disadvantage of harsh,turbid and dark water environments.In order to meet the rapidly development needs of underwater detection technology and serve the needs of marine development strategy,this paper takes the application of active electric field technology as topic,builds an optimized underwater detection experimental platform focused on improving the motion control module.Based on the change of transition frequency and signal amplitude of the electric field caused by the detected object in the active electric field,this paper proposes three underwater shape detection methods.After processing the original data,the geometric shape of the target object on the plane can be obtained clearly.The square wave pulse signal is combined with the sinusoidal signal to detect.The methods are as follows: :1.When the detection is different from different directions of the object,the transition frequency is different,and the shape of the object is determined by using the variation of the turning frequency of the object in all directions;2.When the angle between the detecting electrode and the cross-section of the measured object changes,the detected transition frequency is different,and the object is detected from different positions in the same direction to determine the geometric shape of the object in one direction;3.The measured object in the electric field will cause the amplitude of the received signal voltage to change,and the shape of the object is drawn in combination with the amplitude and the detected orientation.The above three methods were applied to the four prisms,hexagonal prisms,octagonal prisms and cylinders of aluminum,iron and copper for verification and list experimental data analysis.Exploring the principle of the experimental method and the influencing factors of the transition frequency,the following conclusions are drawn:1.There is no obvious correlation between the geometry of the measured object and the transition frequency;2.The time-frequency characteristic curves of the cylinder and the cone have their own characteristics.This kind of conjecture is proposed and preliminarily verified:The change in the transition frequency is related to a number of factors,and the change in geometry causes a change in the resistance value to affect the corner frequency.in the case that other influencing factors are fixed,as the resistance value of the object increases,the transition frequency decreases,and the two are a nonlinear relationship.