Guidance and search algorithms for mobile robots: application and analysis within the context of urban search and rescue

Urban Search and Rescue is a dangerous task for rescue workers and for this reason the use of mobile robots to carry out the search of the environment is becoming common place. These robots are remotely operated and the search is carried out by the robot operator. This work proposes that common search algorithms can be used to guide a single autonomous mobile robot in a search of an environment and locate survivors within the environment. This work then goes on to propose that multiple robots, guided by the same search algorithms, will carry out this task in a quicker time. The work presented is split into three distinct parts. The first is the development of a nonlinear mathematical model for a mobile robot. The model developed is validated against a physical system. A suitable navigation and control system is required to direct the robot to a target point within an environment. This is the second part of this work. The final part of this work presents the search algorithms used. The search algorithms generate the target points which allow the robot to search the environment. These algorithms are based on traditional and modern search algorithms that will enable a single mobile robot to search an area autonomously. The best performing algorithms from the single robot case are then adapted to a multi robot case. The mathematical model presented in the thesis describes the dynamics and kinematics of a four wheeled mobile ground based robot. The model is developed to allow the design and testing of control algorithms offline. With the model and accompanying simulation the search algorithms can be quickly and repeatedly tested without practical installation. The mathematical model is used as the basis of design for the manoeuvring control algorithm and the search algorithms. This design process is based on simulation studies. In the first instance the control methods investigated are Proportional-Integral-Derivative, Pole Placement and Sliding Mode. Each method is compared using the tracking error, the steady state error, the rise time, the charge drawn from the battery and the ability to control the robot through a simple motion. Obstacle avoidance is also covered as part of the manoeuvring control algorithm. The final aspect investigated is the search algorithms. The following search algorithms are investigated, Lawnmower, Random, HillClimbing, Simulated Annealing and Genetic Algorithms. Variations on these algorithms are also investigated. The variations are based on Tabu Search. Each of the algorithms is investigated in a single robot case with the best performing investigated within a multi robot case. A comparison between the different methods is made based on the percentage of the area covered within the time available, the number of targets located and the time taken to locate targets. It is shown that in the single robot case the best performing algorithms have high random elements and some structure to selecting points. Within the multi robot case it is shown that some algorithms work well and others do not. It is also shown that the useable number of robots is dependent on the size of the environment. This thesis concludes with a discussion on the best control and search algorithms, as indicated by the results, for guiding single and multiple autonomous mobile robots. The advantages of the methods are presented, as are the issues with using the methods stated. Suggestions for further work are also presented

Converging Interests, Diverging Realities: Arab League-EU Cooperation

The Arab League (LAS)-European Union (EU)'s relationship is trapped in a cycle of engagement followed by distrust and failure, due to regional dynamics and a lack of resolve. Although the potential for a broad-based partnership exists, the EU's inability to act at pivotal moments, including the pressing situation in Gaza, continues to hinder meaningful collaboration between the two organisations. The LAS-EU partnership, reinforced by shared concerns over regional crises, has been further tested by the deepening Israel-Palestine conflict, emphasising the need for a united front on humanitarian issues and peace processes. The history of their interactions shows a pattern of initial progress followed by periods of stagnation in the face of crises, signalling a need for resilient diplomatic strategies that can break this cycle and foster more consistent collaboration. Previous focus on security threats that are of particular concern to the EU indicates the latter's dominant role in setting the agenda. This dominance reflects underlying issues in the LAS-EU relationship, such as unbalanced power dynamics, partnerships based more on convenience than trust, and mutual misunderstandings. Given the current critical political conditions in the region, particularly the intensifying conflict between Israel and Palestine and the indescribable humanitarian crisis in Gaza, it is crucial for both the EU and LAS to rethink their approach to collaboration. The partnership is currently fragile, threatened by potential regression or even animosity due to mistrust and misunderstanding

Foreign trade developments in Ukraine, Russia, Poland, Lithuania, Belarus & Moldova (1996-2006)

This thesis analyses the key developments in foreign trade for Ukraine, Russia, Poland, Lithuania, Belarus and Moldova on a comparative basis between 1996 and 2006. It examines trade developments and restructuring with the region’s two major trade blocs: the European Union (EU) and the Commonwealth of Independent States (CIS). Using dependable trade models pioneered by Béla Belassa and Herbert Grubel and Peter J. Lloyd, the analyses involve revealed comparative advantage (RCA) and intra-industry trade (IIT) to determine the extent to which structural changes have or have not occurred, which domestic industries are becoming more competitive and the degree of differentiation present. The reason for choosing the aforementioned measurement indices is straightforward. On one hand, RCA identifies those industries that have become relatively more competitive, and attempts to assess whether a given industry enjoys a comparative advantage in production by means of measuring exports. On the other hand, IIT supposes the opposite of comparative advantage theory, and affirms that differences between countries are not the only rationale for trade, because of the presence of increasing returns in scale economies. Thus, it examines the simultaneous import and export of identical, similar or differentiated products in the same industry often between similar countries. Although both indices are usually considered alternatives to each other, there is good reason to see them as complementary. The results of both indices, therefore, provide critical information from which to assess the degree of trade restructuring

Achilles Tendon Ruptures in Two Male Athletes in NCAA Division I: Report of Two Cases

Major tendon ruptures are rare, with an Achilles tendon rupture (ATR) being the most frequent type. Reported cases most commonly involve male recreational athletes who have increased body mass indexes and are between ages 30 and 50 years. We describe two male athletes in Division I of the National Collegiate Athletic Association who underwent surgical repair for treating an ATR associated with running-related activities. In contrast to other cases, both patients had normal body mass indexes. These two cases identify high-level athletes who underwent operative Achilles tendon repair and returned to their sport at a similar level or high level of post-college athletic activity with promising strength and function

Aspects of the biology and cultivation of the waratah (Telopea speciosissima R. Br.)

Using intermittent mist, cuttings of waratah (Telopea speciosissima) were propagated with a high success rate (nearly 100 per cent) when shoots were taken at the commencement of growth in spring

A survey of X-ray emission from 100 kpc radio jets

We have completed a Chandra snapshot survey of 54 radio jets that are extended on arcsec scales. These are associated with flat spectrum radio quasars spanning a redshift range z=0.3 to 2.1. X-ray emission is detected from the jet of approximately 60% of the sample objects. We assume minimum energy and apply conditions consistent with the original Felten-Morrison calculations in order to estimate the Lorentz factors and the apparent Doppler factors. This allows estimates of the enthalpy fluxes, which turn out to be comparable to the radiative luminosities.Comment: Conference Proceedings IAU Symposium No. 313, Extragalactic jets from every angle, pp. 219-224, 4 figure

FDIR for a Biologically Inspired Trenchless Drilling Device

Failure Detection, Isolation and Recovery (FDIR) of autonomous systems working in hazardous conditions is essential. Methods of detection and recovery without intervention are required. This work describes the failure modes currently identified with an autonomous biologically inspired trenchless drilling robotic system. Inverse Simulation is used for detecting failures and is demonstrated on a simulation model of the robotic system. Results from the experiments, show that Inverse Simulation can be used to detect and identify system failures

Modelling and Control of a Biologically Inspired Trenchless Drilling Device

This work presents the methods used and initial findings of the control of the model for an autonomous trenchless drilling device, with bioinspired worm-like locomotion. The model is validated using Inverse Simulation. The initial control is detailed with data from the simulation and experimental device

Linking high-frequency DOC dynamics to the age of connected water sources

Acknowledgments The authors would like to thank our NRI colleagues for all their help with field and laboratory work, especially Audrey Innes, Jonathan Dick, and Ann Porter. We would like to also thank Iain Malcolm (Marine Scotland Science) for providing AWS data and the European Research Council ERC (project GA 335910 VEWA) for funding the VeWa project. Please contact the authors for access to the data used in this paper. We would also like to thank the Natural Environment Research Council NERC (project NE/K000268/1) for funding.Peer reviewedPublisher PD