Explorations in design space: Unconventional electronics design through artificial evolution

Three hypotheses are formulated. First, in the "design space" of possible e lectronic circuits, conventional design methods work within constrained reg ions, never considering most of the whole. Second, evolutionary algorithms. can explore some of the regions beyond the scope of conventional methods, raising the possibility that better designs can be found. Third, evolutiona ry algorithms can in practice produce designs that are beyond the scope of conventional methods, and that are in some sense better. A reconfigurable hardware controller for a robot is evolved, using a conven tional architecture with and without orthodox design constraints. In the un constrained case, evolution exploited the enhanced capabilities of the hard ware. A tone discriminator circuit is evolved on an FPGA without constraint s, resulting in a structure and dynamics that are foreign to conventional d esign and analysis, The first two hypotheses are true. Evolution can explore the forms and processes that are natural to the elect ronic medium, and nonbehavioral requirements can be integrated into this de sign process, such as fault tolerance. ri strategy to evolve circuit robust ness tailored to the task, the circuit, and the medium, is presented. Hardw are and software tools enabling research progress are discussed. The third hypothesis is a good working one: practically useful but radically unconven tional evolved circuits are in sight.