Combining multiple evolved analog circuits for robust evolvable hardware

Redundancy is one of the most important concepts when it comes to designing fault-tolerant systems. For example, if component failures occur, other redundant components can replace the functions of broken parts and the system can still work. The failure of electronic hardware presents a critical threat to the completion of modern aircraft, spacecraft, and robot missions. Compared to digital circuits, designing analog circuits is a difficult and knowledge-intensive task. In this paper, we used evolutionary computation to generate multiple analog circuits automatically and then we combined the solutions to generate robust outputs. Because evolutionary computation refers to a population-based search, multiple, redundant solutions can be maintained. Experimental results on the evolution of the lowpass filter show that the combination of multiple evolved analog circuits produces results that are more robust than those of the best single circuit.