Evolutionary Path Planning with Subpath Constraints

We develop an evolutionary method of planning paths that are subject to subpath constraints. These constraints can include subpaths that must be incorporated into the solution path, path intersection restrictions, and obstacle avoidance. Our method involves two stages. In the first stage, a global solution is found without consideration of any obstacles. In the second stage, local planning is performed to modify the global path to avoid obstacles. Stage one involves a fixed-length chromosome formulation of a genetic algorithm that utilizes existing operators and a new subpath reversal operator. Stage two involves a graph search process. Our algorithm is applicable to the field of printed electronics where continuous-spray processes are used to deposit electrically functional material onto flexible substrates. These processes give rise to the kinds of subpath constraints we have investigated. We evaluate our algorithm by applying it to a representative problem in the printed electronics field.