Urban search and rescue (USAR) simulation system: spatial strategies for agent task allocation under uncertain conditions

Task allocation under uncertain conditions is a key problem for agents attempting to achieve harmony in disaster environments. This paper presents an agent-based simulation to investigate task allocation considering appropriate spatial strategies to manage uncertainty in urban search and rescue (USAR) operations. The proposed method is based on the contract net protocol (CNP) and implemented over five phases: ordering existing tasks considering intrinsic interval uncertainty, finding a coordinating agent, holding an auction, applying allocation strategies (four strategies), and implementing and observing the real environment. Applying allocation strategies is the main innovation of the method. The methodology was evaluated in Tehran's District 1 for 6.6, 6.9, and 7.2 magnitude earthquakes. The simulation began by calculating the numbers of injured individuals, which were 28 856, 73 195, and 111 463 people for each earthquake, respectively. Simulations were performed for each scenario for a variety of rescuers (1000, 1500, and 2000 rescuers). In comparison with the CNP, the standard duration of rescue operations with the proposed approach exhibited at least 13 % improvement, with a maximal improvement of 21 %. Interval uncertainty analysis and comparison of the proposed strategies showed that increased uncertainty led to increased rescue time for the CNP and strategies 1 to 4. The time increase was less with the uniform distribution strategy (strategy 4) than with the other strategies. The consideration of strategies in the task allocation process, especially spatial strategies, facilitated both optimization and increased flexibility of the allocation. It also improved conditions for fault tolerance and agent-based cooperation stability in the USAR simulation system.

LittleBot

<p>Robots to assist in USAR (urban search and rescue) situations have been employed since 2001. Such robots are designed to provide video and sensor feedback to evaluate hazardous environments before human taskforces are sent in. This minimises the risks human personnel are exposed to, while increasing the effectiveness of USAR operations. However, the typically high cost of such robots and the reliance on trained operators puts them out of reach of most USAR teams. In New Zealand, there are no nationally available robots suitable for USAR purposes. This thesis explores the development of new affordable devices that can be deployed for USAR operations, known as LittleBots. Three LittleBot variants are developed. Differing primarily in their locomotive capability, two mobile variants provide tether-less video reconnaissance and selectable gas level readings. The third, stationary variant, may be reconfigured with up to four selectable sensors, and is targeted at providing ongoing environmental monitoring at a disaster site. With all variants costing less than USD $155 in components, LittleBots are sufficiently low cost to be considered disposable, greatly increasing the likelihood they will be employed en masse. The stationary Sentry variant demonstrates a minimum runtime of over 60 hours, while the mobile variants provision up to 6 hours of mobile video reconnaissance. For independent deployment of LittleBots, a compatible Controller device is developed. Through user testing, the Controller device demonstrates easy and intuitive use, with no training required.</p>

LittleBot

<p>Robots to assist in USAR (urban search and rescue) situations have been employed since 2001. Such robots are designed to provide video and sensor feedback to evaluate hazardous environments before human taskforces are sent in. This minimises the risks human personnel are exposed to, while increasing the effectiveness of USAR operations. However, the typically high cost of such robots and the reliance on trained operators puts them out of reach of most USAR teams. In New Zealand, there are no nationally available robots suitable for USAR purposes. This thesis explores the development of new affordable devices that can be deployed for USAR operations, known as LittleBots. Three LittleBot variants are developed. Differing primarily in their locomotive capability, two mobile variants provide tether-less video reconnaissance and selectable gas level readings. The third, stationary variant, may be reconfigured with up to four selectable sensors, and is targeted at providing ongoing environmental monitoring at a disaster site. With all variants costing less than USD $155 in components, LittleBots are sufficiently low cost to be considered disposable, greatly increasing the likelihood they will be employed en masse. The stationary Sentry variant demonstrates a minimum runtime of over 60 hours, while the mobile variants provision up to 6 hours of mobile video reconnaissance. For independent deployment of LittleBots, a compatible Controller device is developed. Through user testing, the Controller device demonstrates easy and intuitive use, with no training required.</p>

Modelling Wireless Robots for Urban Search and Rescue in Artificial Rubble

<p>Using robots to assist rescue personnel in USAR (Urban Search and Rescue) missions is an active area of research. Researchers are developing robots to penetrate into rubble to gather information about the environment and to search for victims. The School of Engineering and Computer Science of Victoria University of Wellington is developing a team of robots, the "robot family" to help at disasters. The robot family is a three-tier system. The first tier the "grandmother" which carries second tier "mother robots" to the rubble. The mother robot each launches a group of the third tier "daughter robots" that will penetrate the rubble surface. The daughter robots will burrow deep into the disaster site. They will be equipped with sensors to search for and locate trapped persons. They are designed to be small, battery operated, low cost and disposable. The team of robots is hierarchically structured and to be remotely monitored by rescue personnel at a safe distance from the rubble via a wireless communication link. This thesis describes the successful implementation of a wireless communication platform for the team of robots. This was verified using a simulated rubble site. A suitable ZigBee wireless module was selected by comparing a list of target brands to form the wireless network. A group of simulated wireless daughter robot models were developed by attaching wireless modules to microcontrollers. An automatic routing wireless network was implemented between the robots. They were deployed into artificial rubble and the communication system was characterised. Proof of concept experiments were carried out and demonstrated that rescue personnel using a computer at a safe distance outside the rubble could successfully establish reliable communication to monitor or control all robots inside the artificial rubble environment.</p>

Modelling Wireless Robots for Urban Search and Rescue in Artificial Rubble

<p>Using robots to assist rescue personnel in USAR (Urban Search and Rescue) missions is an active area of research. Researchers are developing robots to penetrate into rubble to gather information about the environment and to search for victims. The School of Engineering and Computer Science of Victoria University of Wellington is developing a team of robots, the "robot family" to help at disasters. The robot family is a three-tier system. The first tier the "grandmother" which carries second tier "mother robots" to the rubble. The mother robot each launches a group of the third tier "daughter robots" that will penetrate the rubble surface. The daughter robots will burrow deep into the disaster site. They will be equipped with sensors to search for and locate trapped persons. They are designed to be small, battery operated, low cost and disposable. The team of robots is hierarchically structured and to be remotely monitored by rescue personnel at a safe distance from the rubble via a wireless communication link. This thesis describes the successful implementation of a wireless communication platform for the team of robots. This was verified using a simulated rubble site. A suitable ZigBee wireless module was selected by comparing a list of target brands to form the wireless network. A group of simulated wireless daughter robot models were developed by attaching wireless modules to microcontrollers. An automatic routing wireless network was implemented between the robots. They were deployed into artificial rubble and the communication system was characterised. Proof of concept experiments were carried out and demonstrated that rescue personnel using a computer at a safe distance outside the rubble could successfully establish reliable communication to monitor or control all robots inside the artificial rubble environment.</p>

Control of a Hierarchical Team of Robots for Urban Search and Rescue

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

Control of a Hierarchical Team of Robots for Urban Search and Rescue

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

A Remote Synthetic Testbed For Human-Robot Teaming: An Iterative Design Process

Urban Search and Rescue (USAR) missions often involve a need to complete tasks in hazardous environments. In such situations, human-robot teams (HRT) may be essential tools for future USAR missions. Transparency and explanation are two information exchange processes where transparency is real-time information exchange and explanation is not. For effective HRTs, certain levels of transparency and explanation must be met, but how can these modes of team communication be operationalized? During the COVID-19 pandemic, our approach to answering this question involved an iterative design process that factored in our research objectives as inputs and pilot studies with remote participants. Our final research testbed design resulted in converting an in-person task environment to a completely remote study and task environment. Changes to the study environment included: utilizing user-friendly video conferencing tools such as Zoom and a custom-built application for research administration tasks and improved modes of HRT communication that helped us avoid confounding our performance measures.

Building a Synthetic Task Environment to Support Artificial Social Intelligence Research

To support research on artificial social intelligence for successful teams (ASIST), an urban search and rescue task (USAR) was simulated within Minecraft to serve as a Synthetic Task Environment (STE). The goal for the development of the present STE was to create an environment that provides ample opportunities to allow ASI agents to demonstrate the theory of mind by making inferences and predictions of humans’ states and actions in the USAR task environment, and in the future to intervene to improve teamwork in real-time. This paper describes the STE design background, design potentials and considerations, rich data collection opportunities, and potential usage for more broad research.