Lifetime maximization in mobile sensor networks with energy harvesting

This paper investigates mobility strategies of mobile robots to improve the lifetime of a mobile sensor network with energy harvesting capability. The network lifetime problem is formulated as a nonlinear non-convex optimization problem, which is solved distributively by a series of convex approximations and a novel saddle-point computation algorithm. The convergence of the proposed method is guaranteed. Computer simulations showed quick convergence to the optimal solution in most cases, and verified the use of mobility for energy efficiency by showing its significant improvement to the network lifetime and relatively low cost in mobility.

I. Introduction

Advances in mechatronics have enabled mobile robots with sensors and energy-harvesting modules to form a mobile sensor network with energy harvesting capability [1]. Mobile robots with energy-harvesting modules has the capability to capture and store energy from external sources such as solar power, thermal energy, or mechanical vibrations. Due to the uncertainty of harvesting source and a low overall harvest rate, this alternative energy can only be used as a supplement to on-board batteries. For a mobile sensor network system that is expected to operate for a long duration, energy remains a bottleneck and efforts should be spent on the efficient use of energy resources. This paper exploits the mobility of robotic sensor nodes for energy efficiency of the network.