Communications Coverage in Unknown Underground Environments

Abstract

In field robotics, maintaining communications between the user at a stationary basestation and all deployed robots is essential. This task’s difficulty increases when the test environment is underground and the environment is unknown to the operator and robots. A common approach is to place a breadcrumb trail of communications nodes, or radio transceivers, from the deployed robots back to the basestation, autonomously if possible. Current communications network creation approaches fail to implement a near-optimal, if not optimal, approach to communications coverage in unknown environments and fail to maximize communications coverage when the number of radios is limited. We propose a node placement method that takes advantage of robot observations and existing sensor coverage solutions to optimize node location in unknown environments under sensor range and robot connectivity restrictions. In addition, this novel method for communications coverage is based on a method that approaches optimal coverage within 1 − (1/e) of the true optimal coverage in polynomial time, with the added complexity of obeying the parameters of the environment and maintaining communications between the robot and basestation.