This paper discusses the challenge of achieving high bandwidth, distant range wireless communication from mobile robots by way of antenna tracking. In the case of robots traversing rough terrain at moderate speeds, tracking demands high slew rates and large motion ranges due to vehicle motion disturbances. Attaining tracking accuracy, particular with the low mass and power inherent to mobile robots, requires an innovative approach. This paper presents the requirements analysis, mechanism design, sensor configuration and some experimental results for an antenna pointing mechanism that was developed for Nomad, a planetary-relevant mobile robot. The mechanism was demonstrated during the summer of 1997 in Nomad's 200 km traverse in the Atacama Desert of Chile.

In June and July 1997, Nomad, a planetary-relevant mobile robot, traversed more than 220 kilometers across the barren Atacama Desert in Chile, exploring a landscape analogous to the surfaces of the Moon and Mars. In this unprecedented demonstration, Nomad operated both autonomously and under the control of operators thousands of kilometers away, addressing issues of robot configuration, communication, position estimation, and navigation in rugged, natural terrain. The field experiment also served to test technologies for remote geological investigation, paving the way for new exploration strategies on Earth and beyond. Finally, by combining safeguarded teleoperation with panoramic visualization and a novel user interface, the Atacama Desert Trek provided the general public a compelling interactive experience an opportunity to remotely drive an exploratory robot. Nomad's performance in the Atacama Desert Trek set new benchmark in high performance robotics operations relevant to terrestrial and planetary exploration. This paper presents an overview of the experiment, describes technologies key to Nomad's success, and discusses outcomes and implications.

A solid-state inertial measurement unit (IMU) referred to as the MotionPak/sup TM/ is described. The IMU developed by BEI Sensors & Systems Company, consists of three micromachined quartz rate sensors and three accelerometers to provide a six degree of freedom (DOF), miniature, high reliability, low cost motion sensor which Carnegie Mellon University is utilizing to adapt to field robotic applications. Theory of operation and applications of the IMU are presented together with preliminary results in fusing the IMU data with a compass for a field robotics application.