Evolving complex robot behaviors

Building robots is a tough job because the designer has to predict the interactions between the robot and the environment as well as to deal with them. One solution to such diculties in designing robots is to adopt learning methods. The evolution-based approach is a special method of machine learning and it has been advocated to auto-mate the design of robots. Yet, the tasks achieved so far are fairly simple. In this work, we first analyze the diculties of applying evolutionary approaches to synthesize robot controllers for complicated tasks, and then suggest an approach to resolve them. Instead of directly evolving a monolithic control system, we propose to decompose the overall task to fit in the behavior-based control architecture, and then to evolve the separate behavior modules and arbitrators using an evolutionary approach. Consequently, the job of defining fitness functions becomes more straightforward and the tasks easier to achieve. To assess the performance of the developed approach, we evolve a control system to achieve an application task of box-pushing as an example. Experimental re-sults show the promise and eciency of the presented approach. Ó 1999 Elsevie