Wilfrido Alejandro Moreno

Wireless sensor networks for flash-flood alerting

This article presents the ongoing effort in providing the population of the Andean region of Venezuela with a flash-flood alerting system by making use of state-of-the-art wireless communications and information technologies. A key component of the project is a wireless sensor network (WSN) that is used for monitoring the environment and tracking the disaster while it evolves. Currently, the project is at its conceptual inception and system-level design is being carried out. Major design constraints and solutions are presented with an emphasis on the monitoring system based on the WSN.

A Novel Nonlinear Backstepping Controller Design for Helicopters Using the Rotation Matrix

This brief presents a backstepping controller design for helicopters. The controller objective is for the helicopter to autonomously track predefined position and yaw reference trajectories. The incorporation of nested saturation feedback functions in the backstepping design preserves the helicopters motion and power physical constraints. The intermediate control signals related to the attitude dynamics exploit the structural properties of the rotation matrix and are enhanced with terms that guarantee that the helicopter will not overturn while tracking the desired position trajectory. The attitude dynamics are rendered exponentially stable while the translational dynamics are globally asymptotically stable. Numerical simulations illustrate the applicability of the proposed design.

Context-Awareness for Mobile Sensing: A Survey and Future Directions

The evolution of smartphones together with increasing computational power has empowered developers to create innovative context-aware applications for recognizing user-related social and cognitive activities in any situation and at any location. The existence and awareness of the context provide the capability of being conscious of physical environments or situations around mobile device users. This allows network services to respond proactively and intelligently based on such awareness. The key idea behind context-aware applications is to encourage users to collect, analyze, and share local sensory knowledge in the purpose for a large-scale community use by creating a smart network. The desired network is capable of making autonomous logical decisions to actuate environmental objects and also assist individuals. However, many open challenges remain, which are mostly arisen because the middleware services provided in mobile devices have limited resources in terms of power, memory, and bandwidth. Thus, it becomes critically important to study how the drawbacks can be elaborated and resolved and, at the same time, better understand the opportunities for the research community to contribute to the context-awareness. To this end, this paper surveys the literature over the period of 1991-2014 from the emerging concepts to applications of context-awareness in mobile platforms by providing up-to-date research and future research directions. Moreover, it points out the challenges faced in this regard and enlightens them by proposing possible solutions.

Unmanned helicopter waypoint trajectory tracking using model predictive control

A Model Predictive Control Based Trajectory Tracking (MPCTT) system for small unmanned helicopters is presented. A linear model predictive controller is used to take advantage of the fast algorithms available to solve convex optimization problems. The proposed MPCTT system is compared with a velocity tracking and a position tracking system implemented with classical PIDs from previous research work. Obtained simulation results demonstrate the superiority of the proposed MPCTT approach, generating a substantially less control effort in order to track waypoint trajectories. The unmanned helicopter used for the proposed MPCTT system is considered as a (linearized) linear state-space model obtained for hovering and slow motion; however, as shown, the MPCTT is robust enough to perform trajectory tracking under a cruise flight mode, too.

A technique for automated validation of fault tolerant designs using laser fault injection (LFI)

This paper describes the successful development and demonstration of a Laser Fault Injection (LFI) technique to inject soft, i.e., transient, faults into VLSI circuits in a precisely-controlled, non-destructive, non-intrusive manner for the purpose of validating fault tolerant design and performance. The technique described in this paper not only enables the validation of fault-tolerant VLSI designs, but it also offers the potential for performing automated testing of board-level and system-level fault tolerant designs including fault tolerant operating system and application software. The paper describes the results of LFI testing performed to date on test metal circuit structures, i.e., ring oscillators, flip-flops, and multiplier chains, and on an advanced RISC processor, with comprehensive on-chip concurrent error detection and instruction retry, in a working single board computer. Relative to rapid, low cost testing and validation of complex fault tolerant designs, with the automated laser system at the Laser Restructuring Facility at the University of South Florida Center for Microelectronics Research (USF/CMR), a design with 10000 test points could be tested and validated in under 17 minutes. In addition to describing the successful demonstration of the technique to date, the paper discusses some of the challenges that still need to be addressed to make the technique a truly practical fault tolerant design validation tool.

Development of a robotic haptic interface to assist the performance of vocational tasks by people with disabilities

This paper describes the development of intelligent mapping from a haptic user interface to a remote manipulator to assist individuals with disabilities performing vocational tasks. This mapping, referred to an assistance function, is determined on the basis of environmental model or sensory data to guide the motion of a telerobotic manipulator while performing a given task. Human input is enhanced rather than superseded by the computer. Three manual dexterity assessment tests, commonly used in the occupational therapy field, were chosen to implement the several forms of assistance functions designed to augment the human performance. The test bed used for these tasks consisted of a six-degree-of-freedom force-reflecting haptic interface device, PHANToM with the GHOST SDK software. The results demonstrate that the forms of assistance provided reduced the execution times and increased the performance of the chosen tasks. In addition, these results suggest that the introduction of the haptic rendering capabilities, including the force feedback, offers special benefit to motion-impaired users by augmenting their performance on job-related tasks.

A survey of context-aware middleware designs for human activity recognition

The ever increasing technological advances in embedded systems engineering, together with the proliferation of small-size sensor designs and deployment, have enabled smart devices to recognize daily human-based actions, activities, and interactions. Therefore, inferring a vast variety of user-device-based activities from diverse contexts obtained by a series of sensory observations has drawn much interest to the research area of ubiquitous sensing. The existence and awareness of context provides the capability of being conscious of physical environments or situations around users, and this allows network services to respond proactively and intelligently based on such awareness. Hence, with the evolution of smartphones, software developers have been empowered to create context-aware applications for recognizing human-centric or community based innovative social and cognitive activities in any situation and at any location. However, the middleware services provided in mobile devices have limited resources in terms of power, memory, and bandwidth compared to the capabilities of PCs and servers. Also, power is a major restriction on implementation of context-aware applications. Mobile device batteries do not last a long time while operating sensor(s) constantly. To this end, this article extensively surveys the emerging concepts of context awareness in mobile platforms by providing up-to-date literature and future research directives. We also point out the challenges faced in this regard and enlighten them by offering possible solutions.

Heterogeneous Swarm Formation Control Using Bivariate Normal Functions to Generate Potential Fields

A novel method is presented for dynamic heterogeneous swarm formation control with potential fields generated from bivariate normal probability density functions (pdfs) used to construct the surface which swarm members move on, controlling swarm geometry, individual member spacing, and managing obstacle avoidance. Limiting functions are defined to provide tighter swarm control by modifying and adjusting a set of control variables forcing the swarm to behave according to set constraints. Bivariate normal functions and limiting functions are combined to guarantee obstacle avoidance and control swarm member orientation and swarm movement as a whole. This approach compared to others, is simple, computationally efficient, scales well to different swarm sizes, to heterogeneous systems, and to both centralized and decentralized swarm models. The method is applied to a simple vehicle model and simulation results are presented for a heterogeneous swarm of ten robot vehicles following line and ellipse formations

Swarm Formation Control with Potential Fields Formed by Bivariate Normal Functions

A novel method is presented for swarm formation control with potential fields generated from bivariate normal probability density functions (pdfs) that construct the surface the swarm members move upon controlling the swarm geometry and member spacing as well as manage obstacle avoidance. Limiting functions provide tighter swarm control by modifying and adjusting a set of control variables, forcing the swarm to behave according to set constraints. Bivariate normal functions and limiting functions are combined to guarantee obstacle avoidance and control swarm member orientation and swarm movement as a whole. The presented approach, compared to others, is simple, computationally efficient, and scales well to different swarm sizes and swarm models. The method is applied to a simple vehicle model, and simulation results are presented on a homogeneous swarm of ten robot vehicles for different formations

Excimer Vs ND:YAG Laser Creation Of Silicon Vias For 3D Interconnects

Rex A. Lee and Wilfrido A. Moreno Center for Microelectronics Research University of South Florida Tampa, Florida and Richard A. Gassman and Doyle Miller Sandia National Laboratories Albuquerque, New Mexico