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Full-Text Articles in Engineering
Moving Ground Target Tracking In Urban Terrain Using Air/Ground Vehicles, Timothy Mclain, Randal W. Beard, Mark Owen, Huili Yu
Moving Ground Target Tracking In Urban Terrain Using Air/Ground Vehicles, Timothy Mclain, Randal W. Beard, Mark Owen, Huili Yu
Faculty Publications
In this paper, we present a framework for tracking a moving target in urban environments using UAVs in cooperation with UGVs. The framework takes into account occlusions between the sensor and the target. The target state is modeled using the dynamic occupancy grid and the target motion model is built using a second-order Markov chain. Based on the target occupancy grid, we design the path planning algorithm to maneuver the UAV and the UGV to configurations where they can detect the target with high probability. Simulation results show the framework is successful in solving the target tracking problem in urban …
Decentralized Perimeter Surveillance Using A Team Of Uavs, Randal Beard, David Casbeer, Derek Kingston
Decentralized Perimeter Surveillance Using A Team Of Uavs, Randal Beard, David Casbeer, Derek Kingston
Faculty Publications
Sponsorship: NASA, AFOSR. This paper develops a distributed algorithm to maintain a current estimate of the state of the perimeter using a team of UAVs. Using notions of consensus, an algorithm is developed and shown to distribute a UAV team uniformly around the perimeter.
Experiments In Cooperative Timing For Miniature Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Randal W. Beard
Experiments In Cooperative Timing For Miniature Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Randal W. Beard
Faculty Publications
This paper presents experimental results for two cooperative timing missions carried out using a team of three miniature air vehicles (MAVs). Using a cooperative timing algorithm based on coordination functions and coordination variables, the MAV team executed a series of simultaneous arrival and cooperative fly-by missions. In the presence of significant wind disturbances, the average time difference between the first and last vehicle in the simultaneous arrival experiments was 1.6 s. For the cooperative fly-by experiments, the average timing error between vehicle arrivals was 0.6 s. These results demonstrate the practical feasibility of the cooperative timing approach.
Experiments In Cooperative Timing For Miniature Air Vehicles, Timothy Mclain, Derek R. Nelson, Randal W. Beard
Experiments In Cooperative Timing For Miniature Air Vehicles, Timothy Mclain, Derek R. Nelson, Randal W. Beard
Faculty Publications
This paper presents experimental results for two cooperative timing missions carried out using a team of three miniature air vehicles (MAVs). Using a cooperative timing algorithm based on coordination functions and coordination variables, the MAV team executed a series of simultaneous arrival and cooperative fly-by missions. In the presence of significant wind disturbances, the average time difference between the first and last vehicle in the simultaneous arrival experiments was 1.6 s. For the cooperative fly-by experiments, the average timing error between vehicle arrivals was 0.6 s. These results demonstrate the practical feasibility of the cooperative timing approach.
Information Consensus And Its Application In Multi-Vehicle Cooperative Control, Ella Atkins, Randal Beard, Wei Ren
Information Consensus And Its Application In Multi-Vehicle Cooperative Control, Ella Atkins, Randal Beard, Wei Ren
Faculty Publications
In the last two decades, advances in networking and distributed computing have facilitated a paradigm shift from large, monolithic mainframe computers to networks of less expensive, less powerful workstations. One motivation for multi-vehicle systems is to achieve the same gains for mechanically controlled systems as has been gained in distributed computation. Rather than having a single monolithic (and therefore expensive and complicated) machine do everything, the hope is that many inexpensive, simple machines, can achieve the same, or enhanced functionality, through coordination. In essence, the objective is to replace expensive complicated hardware with software and multiple copies of simple hardware. …
Decentralized Cooperative Aerial Surveillance Using Fixed-Wing Miniature Uavs, Randal Beard, Derek Kingston, Timothy W. Mclain, Derek Nelson
Decentralized Cooperative Aerial Surveillance Using Fixed-Wing Miniature Uavs, Randal Beard, Derek Kingston, Timothy W. Mclain, Derek Nelson
Faculty Publications
Numerous applications require aerial surveillance. Civilian applications include monitoring forest fires, oil fields and pipelines, and tracking wildlife. Applications to homeland security include border patrol and monitoring the perimeter of nuclear power plants. Military applications are numerous. The current approach to these applications is to use a single manned vehicle for surveillance. However, manned vehicles are typically large and expensive. In addition, hazardous environments and operator fatigue can potentially threaten the life of the pilot. Therefore, there is a critical need for automating aerial surveillance using unmanned air vehicles (UAVs). This paper gives an overview of a cooperative control strategy …
Cooperative Forest Fire Surveillance Using A Team Of Small Unmanned Air Vehicles, Randal Beard, David Casbeer, Derek Kingston, Timothy W. Mclain, Sai-Ming Li, Raman Mehra
Cooperative Forest Fire Surveillance Using A Team Of Small Unmanned Air Vehicles, Randal Beard, David Casbeer, Derek Kingston, Timothy W. Mclain, Sai-Ming Li, Raman Mehra
Faculty Publications
This research was supported by NASA under STTR contract No. NNA04AA19C to Scientific Systems Company, Inc (SSCI) and Brigham Young University (BYU), and by AFOSR grants F49620-01-1-0091 and F49620-02-C- 0094. The objective of this paper is to explore the feasibility of using multiple low-altitude, short endurance (LASE) unmanned air vehicles (UAVs) to cooperatively monitor and track the propagation of large forest fires. A real-time algorithm for tracking the perimeter of a fire with an on-board infrared sensor is developed. Using this algorithm, we develop a decentralized multiple-UAV approach to monitoring the perimeter of the fire. The UAVs are assumed to …
Kalman Consensus Strategies And Their Application To Cooperative Control, Randal Beard, Derek Kingston, Wei Ren
Kalman Consensus Strategies And Their Application To Cooperative Control, Randal Beard, Derek Kingston, Wei Ren
Faculty Publications
Sponsorship: AFOSR, NSF. In this paper, we propose discrete-time and continuous-time consensus update schemes motivated by the discrete-time and continuous-time Kalman filters. With certainty information encoded into each agent, the proposed consensus schemes explicitly account for relative confidence in the information that is communicated from each agent in the team. We show mild sufficient conditions under which consensus can be achieved using the proposed schemes in the presence of switching interaction topologies. The Kalman consensus scheme is shown to be input-to-state stable. We show how to exploit this fact in multi-agent cooperative control scenarios.
Coordination Variables And Consensus Building In Multiple Vehicle Systems, Tim Mclain
Coordination Variables And Consensus Building In Multiple Vehicle Systems, Tim Mclain
Faculty Publications
Much of the research focus in the cooperative control community has been on formation control problems. This focus may be due to the fact that the group control problem can be reduced to well-established single-agent control problems by employing a leader-follower type control strategy. For example, single-agent path planning and trajectory generation techniques can be employed for the leader, and conventional trajectory tracking strategies can be employed for the followers. Indeed, formation control problems are much like linear systems theory: we search where the light is the brightest. It can be argued that formation control problems are the simplest type …
Initial Experiments In The Cooperative Control Of Unmanned Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Reed S. Christiansen, Randal W. Beard, David Johansen
Initial Experiments In The Cooperative Control Of Unmanned Air Vehicles, Derek R. Nelson, Timothy W. Mclain, Reed S. Christiansen, Randal W. Beard, David Johansen
Faculty Publications
This paper addresses cooperative control for a team of unmanned air vehicles (UAVs). Specifically, a team of three small UAVs is controlled to perform a cooperative timing mission. Starting at loiter locations distributed around the periphery of a 2 km square battle area, the UAVs cooperatively plan paths to arrive at a target at the center of the battle area in sequence at 10 sec intervals. Cooperative path planning is performed using the methodology of coordination variables and coordination functions. Coordination and waypoint path planning are centralized on a ground station computer. Experiments have been performed using BYU’s fleet of …
Cooperative Path Planning For Timing Critical Missions, Timothy W. Mclain, Randal W. Beard
Cooperative Path Planning For Timing Critical Missions, Timothy W. Mclain, Randal W. Beard
Faculty Publications
This paper presents a cooperative path planning approach for teams of vehicles operating under timing constraints. A cooperative control approach based on coordination variables and coordination functions is introduced and applied to cooperative timing problems. Three types of timing constraints are considered: simultaneous arrival, tight sequencing, and loose sequencing. Simulation results demonstrating the approach are presented.
Autonomous Hierarchical Control Of Multiple Unmanned Combat Air Vehicles (Ucavs), Timothy Mclain, Randal W. Beard, Sai-Ming Li, Jovan D. Boskovic, Sanjeev Seereeram, Ravi Prasanth, Jayesh Amin, Raman K. Mehra
Autonomous Hierarchical Control Of Multiple Unmanned Combat Air Vehicles (Ucavs), Timothy Mclain, Randal W. Beard, Sai-Ming Li, Jovan D. Boskovic, Sanjeev Seereeram, Ravi Prasanth, Jayesh Amin, Raman K. Mehra
Faculty Publications
In this paper we present a hierarchical control scheme that enables multiple UCAVs to achieve demanding missions in hostile environments autonomously. The objective is to use a swarm of UCAVs for a SEAD type mission: fly the UCAVs in a formation to an enemy territory populated with different kinds of threats, collect enemy information or destroy certain targets, and return to the base, all without human intervention. The scheme is an integration of four distinct components, including: (1) high level Voronoi diagram based path planner to avoid static threats; (2) low level path planner to avoid popup threats; (3) differential …
Cooperative Control Of Uav Rendezvous, Timothy W. Mclain, Phillip R. Chandler, Steven Rasmussen, Meir Pachter
Cooperative Control Of Uav Rendezvous, Timothy W. Mclain, Phillip R. Chandler, Steven Rasmussen, Meir Pachter
Faculty Publications
The cooperative control of timing and synchronization of tasks of multiple unmanned air vehicles (UAVs) represents a valuable capability for a wide range of potential multi-UAV missions. This research addresses the specific problem of cooperative rendezvous in which multiple UAVs are to arrive at their targets simultaneously. The development of a rendezvous manager state machine and a cooperative control decomposition approach are described. Simulation results demonstrating the feasibility of the approach are presented.
Trajectory Planning For Coordinated Rendezvous Of Unmanned Air Vehicles, Timothy W. Mclain, Randal W. Beard
Trajectory Planning For Coordinated Rendezvous Of Unmanned Air Vehicles, Timothy W. Mclain, Randal W. Beard
Faculty Publications
A trajectory generation strategy that facilitates the coordination of multiple unmanned air vehicles is developed. Of particular interest is the planning of threat-avoiding trajectories that result in the simultaneous arrival of multiple UAVs at their targets. In this approach, paths to the target are modeled using the physical analogy of a chain. A unique strength of the planning approach is the ability to specify or alter the path length by adding or subtracting links from the chain. Desirable paths to the target are obtained by simulating the dynamics of the chain where threats apply repulsive forces to the chain and …