Joshua Freeman

Remote triggered photovoltaic solar cell lab: Effective implementation strategies for Virtual Labs

Remote triggered laboratories are an excellent way to provide access to costly labs and equipment for students in areas without such facilities. A novel remote triggered photovoltaic solar cell experiment is presented here. This experiment enables the student to learn in a hands-on, practical way about the fundamental characteristics of photovoltaic solar cells. The experiment has a web interface in which the student can turn a number of light bulbs on and off, adjust the load voltage of the solar cell, and view the experiment in real-time via a web-cam. In addition, the characteristics of the solar cells under these various conditions are measured and displayed on the web interface in a spreadsheet and are plotted in a novel and learning-effective manner. This experiment has been hosted on our Virtual Labs website for over a year, with a large number of students using the site. This paper presents implementation strategies and methods used which have proven effective for Virtual Labs, along with a technical description of the experiment and the system used to create and host the experiment.

Object recognition and obstacle avoidance robot

Design highlights of a “Three-wheeled Autonomous Navigational Robot” are presented in this paper. An efficient modular architecture is proposed for ease of adding various modules to the robot. Obstacle detection, pattern recognition and obstacle avoidance are the key aspects of the design. The robot has intelligence built into it that enables it to recognize and pick up balls of a particular colour and ignore other objects in its path. A single board computer mounted on the robot acts as the central controller. It communicates with ultrasonic sensors and motors through multiple microcontrollers and controls the entire motion of the unit. As part of the robot design, a modified H-bridge circuit for driving DC motors efficiently is proposed in this paper.

Inverse kinematics of a dual linear actuator pitch/roll heliostat

This work presents a simple, computationally efficient inverse kinematics solution for a pitch/roll heliostat using two linear actuators. The heliostat design and kinematics have been developed, modeled and tested using computer simulation software. A physical heliostat prototype was fabricated to validate the theoretical computations and data. Pitch/roll heliostats have numerous advantages including reduced cost potential and reduced space requirements, with a primary disadvantage being the significantly more complicated kinematics, which are solved here. Novel methods are applied to simplify the inverse kinematics problem which could be applied to other similar problems.

Remote triggered virtual laboratory for Hooke's law using LabVIEW

By the advent of the new millennia there have been notable changes in the way students get their education. Remote triggered labs standout among these education methodologies for their user interaction and active involvement. Remote Triggered Virtual Labs experiments enhance both theoretical and practical learning experience using real time data streaming and analysis. Real time data streaming includes plotting laboratory experiment data values to the user, showing trigger and control buttons and signals and live video streaming of the respective experiment. This paper describes the framework and methodology for the creation of a Remote Triggered Virtual Laboratory experiment for teaching Hookes Law, a key engineering principle in the Mechanics of Solids. It describes how the experiment works from a technical perspective, how the user interacts with and conducts the experiment, and the novel strategies and methodologies used.

Remote monitoring of indoor environment using mobile robot based wireless sensor network

Remote environmental monitoring is one of the important applications of wireless sensor networking technology where spatially distributed sensor nodes are used to monitor environmental parameters and collaboratively transmit their data through the network. This paper discusses the design of a multi robotic platform within a hybrid wireless sensor network to monitor the environmental changes. The system includes a set of static wireless sensor nodes, a set of mobile robots and a central controller. Mobile robots help to reduce traffic congestions and facilitate close monitoring capabilities. For the effective navigation of the robot, the system uses a known map of the environment, sensor readings and the guidance from the wireless sensor network. The combination of more than one technique for navigation significantly reduces the errors in path planning of the mobile robots. The sensing nodes in the network will forward the accumulated data to the central controller for analysis. The central controller will classify the data based on different threshold levels and records the data. If the system detects an event which exceeds current threshold level, then it will provide an early warning to the authorized users of the system.

Study of the errors influencing heliostats for calibration and control system design

“Power tower” or central receivers are a type of solar thermal energy system in which many heliostats, or movable planar mirrors, are used to focus sunlight onto a central receiver located on top of a tower. To design a control and calibration system for power tower systems, a thorough understanding of the numerous errors which can be present is essential. In this work, the various and different types of errors that present themselves in heliostat based solar energy systems are identified, categorized and assessed based on their potential impact and level of difficulty of resolution. The results of this work can be used to aid in designing a control system for heliostats in which the greatest amount of error can be corrected with the least difficulty.

Virtual labs battery and ultracapacitor characterization

Virtual labs help students and professionals to learn subjects practically. Remote triggered virtual labs, in which real hardware is remotely controlled is especially well suited for students who do not have access to high quality, modern, and often expensive lab equipment. It also allows to students to conduct laboratory experiments on their own time and repeat them as often and when necessary. In this paper, we have implemented Energy Storage studies in (batteries and ultra(super)capacitors at the collegiate level through remote triggered virtual labs. The hardware and software system allows the user to study the charge and discharge characteristics of different types of batteries and ultracapacitors. This will create interest for students and professionals to study more on batteries and ultracapacitors and emerge with new ideas on energy storage. In this work, we compare two hardware setups, one made from scratch with low-cost components and the other created using professional, research grade components. The paper focuses on the design, implementation, control system, measurement, communication protocols and integration with the internet for these two testing setups using Labview.

Remote triggered solar energy assessment using a Pyrheliometer and a Pyranometer

Solar energy can be best harnessed by obtaining accurate values of solar radiation intensity for a given location. This work describes the design and implementation of a novel dual axis tracking system, costing a fraction of an equivalent product on the market, which has been developed to measure, remotely analyze, and assess the solar radiation potential using two pyranometers and a pyrheliometer. The three components of the solar irradiance: direct horizontal (DHI), global horizontal (GHI), and direct normal (DNI), can be individually determined with the device. The mounting and tracking mechanism accommodating the pyrheliometer and pyranometers sensors is designed to rotate in both the elevation and azimuth axes, with the tracking position calculated using the SUNAE algorithm. A shading eye is used to separate the DHI from the GHI. The tracking system is implemented in an online remote trigger virtual labs experiment which can be accessed over the internet.

Remote triggered monitoring of wind performance using Weibull and Rayleigh distributions

In this era of depleting fossil fuels and global warming, alternative sources of energy are critical to mankinds survival, making its study imperative for energy engineering students. This work demonstrates the design, development and implementation of a remote triggered experiment to analyze wind data and correlate it with Weibull and Rayleigh distributions performed in coastal Kerala, in southwest India. Interfacing instrumentation with the server and website, in order to collect the wind speed and direction, is enumerated. This work provides a platform that can remotely control, capture and model both short term and long term wind data thereby overcoming a critical barrier in bringing wind energy experimentation to engineering classrooms, namely lack of in-house wind power analysis systems. Additionally, the platform allows testing the feasibility of turbine installations based on predictions from the Rayleigh and Weibull probability distributions.

Closed loop control system for a heliostat field

The alarming energy crisis, heightened by the continuing depletion of fossil fuels, accentuates the need for the development of renewable energy technology, knowledge, and infrastructure. A Central Receiver (Power Tower) Solar Energy system uses heliostats (motorized planar reflectors) to continuously reflect direct radiation from the sun onto a central receiver. This paper discusses a novel closed loop control system for a heliostat field. In this system, rough adjustment of the heliostat is performed using an Inertial Measurement Unit (IMU). Precision adjustment of the heliostat is performed by inducing a small mechanical vibration in the heliostats reflective surface, using a piezoelectric actuator. This vibration creates time-dependent changes in the light waves reflected from the heliostat, which can be detected by photo-sensors surrounding the thermal receiver target. The position of misaligned heliostats can be corrected once they are identified by FFT analysis of the light waves received by the photo-sensors. This technique can, in principle, control thousands of heliostats simultaneously. The control system is coded using MATLAB.