Utilizing Mobility to Minimize the Total Communication and Motion Energy Consumption of a Robotic Operation

Abstract

It is a common assumption that motion costs more than communication and therefore it is always better to increase the transmit power of a robot, in a networked robotic operation, instead of moving to a spot that is better for communication. The goal of this paper is to see if and when this assumption is correct by considering both the communication and motion costs of a robotic operation. More specifically, we consider a scenario where a robot needs to transmit a given number of bits to a remote station under time constraint and Bit Error Rate (BER) requirement, and while minimizing the total energy consumption. The robot is allowed to move along a predefined trajectory and design its transmission rate/power and motion policy (motion speed and possible stop times) accordingly. We then address the following question: should the robot send the given information at its initial position, or spend energy on motion and move to a location with a better communication quality? By co-optimizing the communication and motion strategies of the robot, we characterize the properties of the optimum policy, which shows that under several conditions it is more beneficial for the robot to spend energy on motion in order to move to a location that is better for communication. We also discuss a special case to see how the channel parameters and motion energy model impact the motion decision of the robot. Our simulation results show that, by using our strategy, the robot can reduce its total energy cost significantly.