An issue central to the navigation problem is memory.
Traditional systems build symbolic maps of the world for navigational reference.
Reactive methods, in contrast, eliminate or minimize the use of memory. These reactive techniques have been remarkably successful at solving a wide range of navigational problems. The addition of a local spatial memory allows a robot to avoid areas that have already been visited. 1993 IEEE International Conference on Robotics and Automation, Atlanta, GA, May 1993, pp. Dean The graph only includes citing articles where the year of publication is known.