James M. Conrad

A survey of energy harvesting sources for embedded systems

Historically, batteries have been the source of energy for most mobile, embedded and remote system applications. Now, with ubiquitous computing requirements in the fields of embedded systems, wireless sensor networks and low- power electronics such as MEMS devices, an alternative source of energy is required. Also with the limited capacity of finite power sources and the need for supplying energy for a lifetime of a system, there is a requirement for self- powered devices. The process of extracting energy from the surrounding environment is termed as energy harvesting. Energy harvesting, which originated from the windmill and water wheel, is widely being considered as a low- maintenance solution for a wide variety of applications. There are various forms of energy that can be scavenged, like thermal, mechanical, solar, acoustic, wind, and wave. This paper serves as a survey for identifying the sources of energy harvesting based on various technical papers available in the public domain.

Time synchronization in wireless sensor networks: A survey

Wireless sensor networks consist of small devices distributed over geographical area. Each one of these devices has sensing, computing, and communicating components. Wireless sensor networks are used in many applications where partial or full time synchronization in the network is required. Time synchronization aims at equalizing the local times for all nodes in the network, if necessary. Since wireless sensor networks are limited in energy resources, computation capability, storage capacity, and bandwidth, traditional time synchronization algorithms like Network Time Protocol (NTP) and Global Positioning System (GPS) are impractical to synchronize the network. This paper explains the time synchronization problem in wireless sensor networks and details the basic algorithms proposed in this area.

Survey of popular robotics simulators, frameworks, and toolkits

Robotic simulators, frameworks, and related toolkits are very important in todays research community. The need to accurately simulate movements, algorithms, and interactions with the real world is quickly becoming a major research focus as humans and robots interact in more situations and differently than ever before. This is a survey of popular robotics simulators and some of the main frameworks and toolkits that are used to help bring robotics simulations to a one-to-one relationship with real-world interaction.

Wireless industrial sensor networks: framework for QoS assessment and QoS management.

This paper presents a framework that addresses Quality of Service (QoS) for industrial wireless sensor networks as a real-time measurable set of parameters within the context of feedback control, thereby facilitating QoS management. This framework is based on examining the interaction between the industrial control processes and the wireless network. Control theory is used to evaluate the impact of the control/communication interaction, providing a methodology for defining, measuring, and quantifying QoS requirements. An example is presented illustrating the wireless industrial sensor network (WISN) QoS management framework for providing dynamic QoS control within WISN. The example focuses on WISN operating in a time-varying RF interference environment in order to manage application-driven QoS latency constraints.

Extended energy model for the low rate WPAN

Energy efficiency is a major concern in wireless sensor networks (WSNs) and as such power control policies play an essential component in maximizing a networks lifetime. Optimal power control policies provide the correct trade-off in balancing packet transmission reliability within the operational environment with expanded energy based on the wireless transceiver characteristics. In this paper, an extension of an energy model previously developed for the Chipcon CC2420, an IEEE802.15.4trade device, is presented. The approach provides an extended energy model taking into account transitions energy cost between the Chipcon CC2420 operational states. The empirical testbed used to obtain the measured data is presented along with a summary of the measurements. A comparison is made between the extended model and the previous model to illustrate the importance of incorporating the transition energy requirements

Bluetooth communication using a touchscreen interface with the Raspberry Pi

The Raspberry Pi is a low cost single-board computer which has recently become very popular. In this paper we showcase our attempt at building a low cost stand-alone device which transmits data using the Raspberry Pi with Bluetooth and has a resistive touch screen display providing a user interface. The Raspberry Pi is controlled by a modified version of Debian Linux optimized for the ARM architecture. The display contains a graphical user interface which provides various fields for data entry via an onscreen keyboard. Also, various fields were provided to display data obtained from a remote host.

A survey of robotic applications in wireless sensor networks

Robotics can have many applications in wireless sensor networks. Robotics can be used to help solve many problems in wireless sensor networks, such as localizing nodes, acting as data mules, repositioning nodes, detecting and reacting to sensor failure, aggregate sensor data, and even sometimes provide mobile battery chargers for the nodes. Inversely, wireless sensor networks can help solve many problems in robotics, such as localization of the robot, path planning, mapping, and sensing.

Human-robot collaboration: A survey

Human-Machine collaboration is a vastly developing field in the area of Robotics. This paper introduces the concept of such collaboration and describes its use in various facets of our society. The various kinds of interaction between humans and robots in applications such as elderly care, schools and education, medicine, military and space exploration have been reviewed in this paper. Also, the learning process used by the robot for interacting with the human and environment is presented.

Components of an autonomous all-terrain vehicle

The purpose of this report is to present research conducted into robotic control techniques for a particular all-terrain vehicle (ATV) project. This project covered the design of control circuitry for the ATVs power steering system and power brakes. It also covered the design of the software to decode signals from a remote control that is typically utilized in radio controlled airplanes or helicopters. Finally, the project covered the design of software to operate the control circuitry for the ATVs power steering system and power brakes. Information collected from this project will aid in future robotic projects and robotic courses taught at the University of North Carolina at Charlotte (UNC Charlotte).

Visible light communication using a digital camera and an LED flashlight

This paper presents an approach for optical communication via visible light using a focusable LED flashlight as the transmitting device and a digital camera as the receiver. One novelty of the approach is that the design can integrate generic off-the-shelf light source and camera components and is designed to work indoors under typical lighting conditions, i.e., overhead lighting and ambient daylight. The communication signal is transmitted as a sequence of (1,0) values that turn on/off the light source. A camera receives the signal by observing the presence/absence of the projected light spot on an intervening surface and converting this back into a (1,0) binary signal. The approach applies image processing techniques to compute the received signal from a recorded camera image.