Design And Implementation Of Chaotic Memristive System Based On FPGA

Memristor is the fourth basic circuit element besides resistance,capacitance and inductance.Due to its unique memory,chaotic memristive circuit has more dynamic behavior than general chaotic circuit.In this paper,three kinds of chaotic memristive circuits,namely Chua's memristive circuit,single T memristive circuit and delayed memristive circuit,are constructed by using different types of RC oscillator circuit and memristor.The specific works of this paper are as follows:1.Taking the model of cubic smooth memristor as an example,three kinds of equivalent Chua's memristive chaotic circuits are designed by coupling with the equivalent LC parallel circuit,and the circuit simulation are carried out to obtain experimental results consistent with theoretical analysis and numerical calculation.2.The series and parallel chaotic memristive circuits are designed by using the RC single T frequency selective network and the model in different coupling ways,study the effects of initial value and circuit element parameters on circuit dynamics.3.The delay signals are introduced into the Wien bridge memristive circuit and single T memristive circuit respectively,two kinds of delayed memristive chaotic circuits are designed,and the effects of initial value and circuit element parameters on the dynamic characteristics of the circuit are studied.4.The equivalent Chua's memristive chaotic circuit,single T memristor chaotic circuit and delayed memristive chaotic circuit are realized by FPGA.The chaotic attractor can be generated simply,conveniently and effectively through FPGA,and the actual result is consistent with the numerical calculation result and simulation result.5.Image scrambling and image pixel diffusion are combined to encrypt the image.Firstly,the image is scrambled by improving the generalized Arnold transform,and then the image is diffused based on the single T memristive chaotic sequence and delayed memristive chaotic sequence respectively.In order to further prove its encryption effect,Lorenz chaotic system is introduced to encrypt by the same method,and it is found that memristive chaotic sequence is used to encrypt with more complex topological structure,which improve the security of image encryption and decrypted the ciphertext into plaintext image.In addition,this paper uses histogram method,correlation analysis of adjacent pixels and sensitivity analysis method to judge the encryption effect of the algorithm.Through analysis and comparison,it is concludedthat the use of delayed memristive chaotic system for encryption and decryption is better.In this paper,a variety of chaotic memristive circuits are designed and implemented in hardware by FPGA,so as to provide useful reference for the design of chaotic memristive circuits.