2000 Volume 15 Issue 5 Pages 844-853
In this paper, we describe a GA system based on variable length chromosomes. Our goal is to establish "analog evolvable hardware", i. e., analog EHW.Analog hardware is vulnerable to the environment, such as temperature, and traditional methods to deal with the environmental disturbance are complicated and ad-hoc so that they are not fit for designing a large-scale circuit. In the EHW approach, noises and errors are fed back from the manufacturing process to the designing process. These processes are repeated until the adapted hardware is acquired. Thus, the EHW is robust to the external disturbance. This paper introduces a new approach to the analog EHW. We use a component-list representation, which has the advantage of enabling the design flexibility, i. e., the capability of acquiring more various functions. We can also properly size a circuit without designer's specification. Our system also features the two-stage evolution, i. e., the structural adaptation of the circuit topology and the parameter adaptation by tuning up the elements'values. This division is aimed at achieving more efficient global search with local modification. We show experiments which support the superiority of our approach over conventional approaches in terms of robustness and computational cost.
