Consensus-based control for a network of diffusion PDEs with boundary local interaction

In this paper the problem of driving the state of a network of identical agents, modeled by boundary-controlled heat equations, towards a common steady-state profile is addressed. Decentralized consensus protocols are proposed to address two distinct problems. The first problem is that of steering the states of all agents towards the same constant steady-state profile which corresponds to the spatial average of the agents initial condition. A linear local interaction rule addressing this requirement is given. The second problem deals with the case where the controlled boundaries of the agents dynamics are corrupted by additive persistent disturbances. To achieve synchronization between agents, while completely rejecting the effect of the boundary disturbances, a nonlinear sliding-mode based consensus protocol is proposed. Performance of the proposed local interaction rules are analyzed by applying a Lyapunov-based approach. Simulation results are presented to support the effectiveness of the proposed algorithms

Adaptive sampling for spatial prediction in environmental monitoring using wireless sensor networks: A review

© 2018 IEEE. The paper presents a review of the spatial prediction problem in the environmental monitoring applications by utilizing stationary and mobile robotic wireless sensor networks. First, the problem of selecting the best subset of stationary wireless sensors monitoring environmental phenomena in terms of sensing quality is surveyed. Then, predictive inference approaches and sampling algorithms for mobile sensing agents to optimally observe spatially physical processes in the existing works are analysed

Behavior planning for automated highway driving

This work deals with certain components of an automated driving system for highways, focusing on lane change behavior planning. It presents a variety of algorithms of a modular system aiming at safe and comfortable driving. A major contribution of this work is a method for analyzing traffic scenes in a spatio-temporal, curvilinear coordinate system. The results of this analysis are used in a further step to generate lane change trajectories. A total of three approaches with increasing levels of complexity and capabilities are compared. The most advanced approach formulates the problem as a linear-quadratic cooperative game and accounts for the inherently uncertain and multimodal nature of trajectory predictions for surrounding road users. Evaluations on real data show that the developed algorithms can be integrated into current generation automated driving software systems fulfilling runtime constraints

Distributed allocation of mobile sensing swarms in gyre flows

We address the synthesis of distributed control policies to enable a swarm of homogeneous mobile sensors to maintain a desired spatial distribution in a geophysical flow environment, or workspace. In this article, we assume the mobile sensors (or robots) have a "map" of the environment denoting the locations of the Lagrangian coherent structures or LCS boundaries. Based on this information, we design agent-level hybrid control policies that leverage the surrounding fluid dynamics and inherent environmental noise to enable the team to maintain a desired distribution in the workspace. We establish the stability properties of the ensemble dynamics of the distributed control policies. Since realistic quasi-geostrophic ocean models predict double-gyre flow solutions, we use a wind-driven multi-gyre flow model to verify the feasibility of the proposed distributed control strategy and compare the proposed control strategy with a baseline deterministic allocation strategy. Lastly, we validate the control strategy using actual flow data obtained by our coherent structure experimental testbed.Comment: 10 pages, 14 Figures, added reference

Cooperative and Distributed Algorithms for Dynamic Fire Coverage using a Team of UAVs

Recent large wildfires in the United States and subsequent damage that they have caused have increased the importance of wildfire monitoring and tracking. However, human monitoring on the ground or in the air may be too dangerous and therefore, there needs to be alternatives to monitoring wildfires. Unmanned Aerial Vehicles (UAVs) are currently being considered and used for applications such as reconnaissance, surveying, and monitoring in the spatial-time domain because they can be deployed in teams remotely to gather information and minimize the harm and risk to human operators. UAVs have been previously used in this problem domain to track and monitor wildfires with approaches such as potential fields and reinforcement learning. In this thesis, we aim to look at a team of UAVs, in a distributed approach, over an area to maximize the sensor coverage in dynamic wildfire environments and minimize the energy consumption of deployed UAVs in a network. The work implements and compares an implementation of Deb's NSGA-II to optimize potential fields, Experience Replay with Q-learning, a Deep Q-Network (DQN), and a Deep Q-Network with a state estimator (autoencoder) to track and cover wildfires. The application of this work is a not a final suggestion or an absolute solution for wildfire monitoring and tracking but instead compares the methods to declare the most promising method for future work and research

Multistep predictions for adaptive sampling in mobile robotic sensor networks using proximal ADMM

This paper presents a novel approach, using multi-step predictions, to the adaptive sampling problem for efficient monitoring of environmental spatial phenomena in a mobile sensor network. We employ a Gaussian process to represent the spatial field of interest, which is then used to predict the field at unmeasured locations. The adaptive sampling problem aims to drive the mobile sensors to optimally navigate the environment while the sensors adaptively take measurements of the spatial phenomena at each sampling step. To this end, an optimal sampling criterion based on conditional entropy is proposed, which minimizes the prediction uncertainty of the Gaussian process model. By predicting the measurements the mobile sensors potentially take in a finite horizon of multiple future sampling steps and exploiting the chain rule of the conditional entropy, a multi-step-ahead adaptive sampling optimization problem is formulated. Its objective is to find the optimal sampling paths for the mobile sensors in multiple sampling steps ahead. Robot-robot and robot-obstacle collision avoidance is formulated as mixed-integer constraints. Compared with the single-step-ahead approach typically adopted in the literature, our approach provides better navigation, deployment, and data collection with more informative sensor readings. However, the resulting mixed-integer nonlinear program is highly complex and intractable. We propose to employ the proximal alternating direction method of multipliers to efficiently solve this problem. More importantly, the solution obtained by the proposed algorithm is theoretically guaranteed to converge to a stationary value. The effectiveness of our proposed approach was extensively validated by simulation using a real-world dataset, which showed highly promising results. © 2013 IEEE