In a multi-robot system, robots are typically required to collaborate over a communication network to achieve objectives cooperatively. Due to the limited communication and sensing capabilities on each robot, the cooperative objective must be accomplished while ensuring that specified robots stay within each other's sensing and communication ranges and that the overall network remains connected. In this paper, a dipolar navigation function and corresponding time-varying continuous controller is developed for repositioning and reorienting a group of wheeled robots with nonholonomic constraints. Only local sensing feedback information from neighbors is used to navigate the robots and maintain network connectivity, which indicates that communication is available when required for various tasks, but communication is not required for navigation. Simulation results demonstrate the performance of the developed approach.