Abstract: Aiming at the problems of low optimization accuracy,easy to fall into local optimization and slow convergence speed of COOT bird algorithm,a logistic chaos CDLCOOT algorithm based on Cauchy mutation and differential evolution is proposed.Firstly,the position of the COOT bird is disturbed by Cauchy mutation to expand the search range and improve the global search ability of the algorithm.Secondly,the differential evolution strategy is adopted for the leader COOT bird to increase the population diversity,so that the leader with better fitness can lead the population to search for the optimal solution,guide the individual COOT bird to move towards the optimal solution,and help it search faster.Finally,the logistic chaos factor is added to the chain movement of the COOT bird,so as to realize the chaotic chain following movement and improve the ability of the algorithm to jump out of the local optimum.Simulation experiments are carried out on 12 classical test functions and 9 CEC2017 test functions.The CDLCOOT algorithm is compared with other advanced algorithms,such as the sine cosine algorithm(SCA),gray wolf optimizer(GWO),ant lion optimizer(ALO),multi-verse optimizer(MVO),as well as original COOT bird algorithm and the original algorithm with single strategy to verify the effectiveness of the improved algorithm.Experimental results show that CDLCOOT has better global optimization ability and faster convergence speed than other heuristic algorithms and improved algorithms.In the classical test functions,the average value of the algorithm is 76 orders of magnitude higher than that of the original algorithm on the four unimodal functions.The theoretical optimal value is found on two multimodal functions,and the average value on other two multimodal functions is 3 or 4 orders of magnitude higher than the original algorithm.On the four fixed dimension multimodal functions,the algorithm can find the theoretical optimal value,and the convergence speed is faster.In CEC2017 test functions,the optimization accuracy of the algorithm in unimodal,multimodal and hybrid functions is improved compared with the original algorithm,and its convergence speed is also superior to the original algorithm and other algorithms,and the stability of the algorithm is better.

Key words: COOT bird algorithm, Cauchy mutation, Differential evolution, Logistic chaos