A cohesive langrangian swarm and its application to multiple unicycle-like vehicles

Swarm principles are increasingly being used to design controllers for the coordination of multi-robot systems or, in general,multi-agent systems. This paper proposes a two-dimensional Lagrangian swarm model that enables the planar agents, modeled as point masses, to swarm whilst effectively avoiding each other and obstacles in the environment. A novel method, based on an extended Lyapunov approach, is used to construct the model. Importantly, the Lyapunov method ensures a form of practical stability that guarantees an emergent behavior, namely, a cohesive and wellspaced swarm with a constant arrangement of individuals about the swarm centroid. Computer simulations illustrate this basic feature of collective behavior. As an application, we show how multiple planar mobile unicycle-like robots swarm to eventually form patterns in which their velocities and orientations stabilize

Intelligent home: SMS based home security system with immediate feedback

A low cost Short Message System (SMS) based Home security system equipped with motion, smoke, temperature, humidity and light sensors has been studied and tested. The sensors are controlled by a microprocessor PIC 18F4520 through the SMS having password protection code for the secure operation. The user is able to switch light and the appliances and get instant feedback. Also in cases of emergencies such as fire or robbery the system will send alert message to occupant and relevant civil authorities. The operation of the home security has been tested on Vodafone- Fiji network and Digicel Fiji Network for emergency and feedback responses for 25 samples. The experiment showed that it takes about 8-10s for the security system to respond in case of emergency. It takes about 18-22s for the occupant to switch and monitor lights and appliances and then get feedback depending upon the network traffic

New ICT Tools in Higher Education for the USP Region

The presentation will basically cover the new ICT tools and technologies we have incorporated into our education system at The University of the South Pacific (USP). The University was set up in the South Pacific region in 1968 by its 12 member countries - Cook Islands, Republic of Fiji, Kiribati, Marshall Islands, Nauru, Niue, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu and Vanuatu. A total of 14 campuses are spread over an area of 30 million square kilometres of the Pacific Ocean. This geographical separation necessitates a commitment from USP to take its products and services to the doorstep of each and every household of its member countries. Therefore, coming up with better learning and teaching tools and culture-inclusive curriculum for the region is one of the aortal aims of the university. We also understand that ICT solutions designed in the developed countries may not be suitable or easily adopted by the regional countries due to their unique restrictions and challenges. These may include the language barrier, high costs of internet and devices, slow and intermittent connectivity, socio-economic background of the users, shoestring budgets, etc. Therefore, the onus is on leading institutions to design services and products tailored for the region. The other need for ICT-driven education in the region is to curb and curtail the digital divide glaringly visible between the developed and developing countries. USP has taken a leading role to address this divide

Obstacle and Collision Avoidance Control Laws of a Swarm of Boids

This paper proposes a new obstacle and collision avoidance control laws for a three-dimensional swarm of boids. The swarm exhibit collective emergent behaviors whilst avoiding the obstacles in the workspace. While flocking, animals group up in order to do various tasks and even a greater chance of evading predators. A generalized algorithms for attraction to the centroid, inter-individual swarm avoidance and obstacle avoidance is designed in this paper. We present a set of new continuous time-invariant velocity control laws is presented which is formulated via the Lyapunov-based control scheme. The control laws proposed in this paper also ensures practical stability of the system. The effectiveness of the proposed control laws is demonstrated via computer simulations

Motion Planning and Posture Control of Multiple n-link Doubly Nonholonomic Manipulators

The paper considers the problem of motion planning and posture control of multiple n-link doubly nonholonomic mobile manipulators in an obstacle-cluttered and bounded workspace. The workspace is constrained with the existence of an arbitrary number of fixed obstacles (disks, rods and curves), artificial obstacles and moving obstacles. The coordination of multiple n-link doubly nonholonomic mobile manipulators subjected to such constraints becomes therefore a challenging navigational and steering problem that few papers have considered in the past. Our approach to developing the controllers, which are novel decentralized nonlinear acceleration controllers, is based on a Lyapunov control scheme that is not only intuitively understandable but also allows simple but rigorous development of the controllers. Via the scheme, we showed that the avoidance of all types of obstacles was possible, that the manipulators could reach a neighborhood of their goal and that their final orientation approximated the desired orientation. Computer simulations illustrate these results. KEYWORDS: Lyapunov-based control scheme; Doubly nonholonomic manipulators; Ghost parking bays; Minimum distance technique; Stability; Kinodynamic constraints

Motion planning and posture control of the general 3 - trailer system

This paper presents a set of artificial potential field functions that improves upon, in general, the motion planning and posture control, with theoretically guaranteed point and posture stabilities, convergence and collision avoidance properties of the general3-trailer system in a priori known environment. We basically design and inject two new concepts; ghost walls and the distance optimization technique (DOT) to strengthen point and posture stabilities, in the sense of Lyapunov, of our dynamical model. This new combination of techniques emerges as a convenient mechanism for obtaining feasible orientations at the target positions with an overall reduction in the complexity of the navigation laws. Simulations are provided to demonstrate the effectiveness of the controls laws

Motion Planning and Control of a Swarm of Boids in a 3-Dimensional Space

In this paper, we propose a solution to the motion planning and control problem for a swarm of three-dimensional boids. The swarm exhibit collective emergent behaviors within the vicinity of the workspace. The capability of biological systems to autonomously maneuver, track and pursue evasive targets in a cluttered environment is vastly superior to any engineered system. It is considered an emergent behavior arising from simple rules that are followed by individuals and may not involve any central coordination. A generalized, yet scalable algorithm for attraction to the centroid and inter-individual swarm avoidance is proposed. We present a set of new continuous time-invariant velocity control laws, formulated via the Lyapunov-based control scheme for target attraction and collision avoidance. The controllers provide a collision-free trajectory. The control laws proposed in this paper also ensures practical stability of the system. The effectiveness of the control laws is demonstrated via computer simulations

Motion control of a 2 - link revolute manipulator in an obstacle - ridden workspace

In this paper, we propose a solution to the motion control problem of a 2-link revolute manipulator arm. We require the end-effector of the arm to move safely to its designated target in a priori known workspace cluttered with fixed circular obstacles of arbitrary position and sizes. Firstly a unique velocity algorithm is used to move the end-effector to its target. Secondly, for obstacle avoidance a turning angle is designed, which when incorporated into the control laws ensures that the entire robot arm avoids any number of fixed obstacles along its path enroute the target. The control laws proposed in this paper also ensure that the equilibrium point of the system is asymptotically stable. Computer simulations of the proposed technique are presented

The Online Mathematics Diagnostic Test at USP: A Tool to Identify Numeracy Gap

The Curriculum - Bridging gap between secondary level education and tertiary level is a major problem which is always unnoticed by many Universities. The Faculty of Science Technology and Environment at the University of the South Pacific has designed an Online Mathematics Diagnostic Test (OMDT) for all its first year undergraduate students to bridge the gap in areas of Mathematics. Many universities issue mathematical diagnostic tests to incoming first-year students, covering a range of basic concepts which the students are supposed to bring with them from their secondary school of studies. It provides an early indication of which students are likely to need additional help (online remedial), and hopefully encourage such students to take advantage of extra support mechanisms at an early stage before the hardcore university studies begins. However, it is not clear that students recognize these intentions and there is a fear that students who score poorly in the test will have their confidence further damaged in relation to mathematics and will be reluctant to seek help. Thus this paper showcases the extend of OMDT designed for new students at USP and the offering of remedial through the eLearning Platform with the detailed analysis of the research carried out with its implementation