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This paper presents a novel approach that employs coordinated robot swarms to create a spatial map for parameters of underwater acoustic communication channels. Understanding spatial variations of acoustic channel parameters is crucial to underwater networking with mixed static and mobile communication nodes. We envision using multiple marine robots maintained in a formation to collect simultaneous measurements of communication signals transmitted by a sound source. The data collected is processed by a cooperative filtering algorithm to generate a local map of a class of channel parameters. The motion of the robots will then be planned by an explorability based method to facilitate map construction under the influence from uncertainty in channel parameters. Our work integrates robotic mapping methods with underwater acoustic communication channel modeling and identification algorithms. We have also combined simulation tools from robotic map making and acoustic channel simulations, which may be valuable for future field experiments.

We analyze the effects of communication delays in teleoperation systems using dissipativity theory along with explicit models of the operator and robot. We utilize a simple model of the operator's behavior that describes human pointing motions, as generated by an interface such as a mouse pointer or tablet, and we use a robot model that is suitable for mobile robots or robotic manipulators. Using dissipativity conditions for stability, we show that the communication delays can be compensated for in the robot controller with a relatively simple extension to a controller designed for the situation without delays. We also show that the communication delays can lead to problems for human pointing in certain situations; specifically, if the operator overshoots their target, it may lead to instability unless corrective action is taken by the user interface. Simulation is shown to validate the results.

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Pointer acceleration is often used in computer mice and other interfaces to increase the range and speed of pointing motions without sacrificing precision during slow movements. However, the effects of pointer acceleration are not yet well understood. We use a system perspective and feedback control to analyze the effects of pointer acceleration. We use a new pointer acceleration model connected in feedback with the vector integration to endpoint model for pointing motions. When there are no feedback delays, we prove global asymptotic stability of the closed loop system for a general class of acceleration profiles. We also prove robustness under delays and perturbations by building Lyapunov-Krasovskii functionals for delay systems, and we find state performance bounds using robust forward invariance with maximal perturbation sets. The results are relevant to designing pointing interfaces, and our simulations illustrate the good performance of our control under realistic operating conditions.In this work, we use a systems perspective to approach the problem of analyzing the effects of pointer acceleration. We build a dynamic model of human pointing motion with pointing acceleration, and we analyze its performance and stability properties. Our results provide insights into the impact of pointer acceleration in pointer interfaces, and have the potential to benefit future designs of such interfaces.Human pointing interfaces have been studied extensively in human-computer interaction, neuroscience, physiology, and psychology; see [5]. Two key results are the Fitts Law, which was was first presented in [6] and explains an invariant in pointing performance for many human pointing interfaces and tasks, and the vector integration to endpoint (or VITE) model, which was first presented in [7] and reproduces the Fitts Law by describing pointing motions. Other papers have analyzed the dynamics of human pointing as described by the VITE model; see [8][9][10][11][12], with some having feedback delays and some not having delays. Our work [13] used dissipativity to design and study pointing systems, and it gave a preliminary analysis of the VITE model in the dissipativity framework using a switching controller. Our conference article [14] presented the new model of pointer acceleration that is used in this paper and analyzed its stability and performance properties when connected in feedback to the VITE model without any feedback delays or perturbations or robust forward invariance.Our approach is novel because, to the best of our knowledge, we are the first to use a systems perspective to study pointer acceleration. We use a new model that captures most existing implementations of pointer acceleration, and we show that when the VITE dynamics are connected in feedback to the pointer acceleration model, the interconnection is globally asymptotically stable, including in cases with feedback delays. We include a robustness analysis under perturbations, which can arise from discretization errors and inaccuracies in human perception a...