Relative Location Information Acquisition without Direct Distance Measurement in Mobile System

Relative location information among multiple mobile nodes is critical for cooperative and competitive applications in mobile distributed systems. One of the effective conventional methods does not measure distances between pairs of mobile nodes directly. Angles formed by sets of three mobile nodes are achieved by camera images taken by omni-directional cameras mounted on all the mobile nodes. Search for sets of interior angles of triangles and measurement of distance between a pair of mobile nodes provides relative location information. This paper extends this conventional method to achieve the relative location information without direct measurement of distance between mobile nodes. Here, camera images are taken by all the omni-directional cameras synchronously two times, two mobile nodes are required to suspend their mobility temporarily and the other mobile nodes measure their mobility distances. The computational overhead for the proposed method is not so higher than the conventional method since the additional procedure for achieving distance between the mobility suspended mobile nodes is localized.