The PHD: A Planar, Harmonic Drive Robot for Joint Torque Control

This thesis details the development of a model of a seven degree of freedom manipulator for position control. Then, it goes on to discuss the design and construction of a the PHD, a robot built to serve two purposes: first, to perform research on joint torque control schemes, and second, to determine the important dynamic characteristics of the Harmonic Drive. The PHD, is a planar, three degree of freedom arm with torque sensors integral to each joint. Preliminary testing has shown that a simple linear spring model of the Harmonic Drive's flexibility is suitable in many situations.

Trajectory and Force Control of a Direct Drive Arm

Using the MIT Serial Link Direct Drive Arm as the main experimental device, various issues in trajectory and force control of manipulators were studied in this thesis. Since accurate modeling is important for any controller, issues of estimating the dynamic model of a manipulator and its load were addressed first. Practical and effective algorithms were developed fro the Newton-Euler equations to estimate the inertial parameters of manipulator rigid-body loads and links. Load estimation was implemented both on PUMA 600 robot and on the MIT Serial Link Direct Drive Arm. With the link estimation algorithm, the inertial parameters of the direct drive arm were obtained. For both load and link estimation results, the estimated parameters are good models of the actual system for control purposes since torques and forces can be predicted accurately from these estimated parameters. The estimated model of the direct drive arm was them used to evaluate trajectory following performance by feedforward and computed torque control algorithms. The experimental evaluations showed that the dynamic compensation can greatly improve trajectory following accuracy. Various stability issues of force control were studied next. It was determined that there are two types of instability in force control. Dynamic instability, present in all of the previous force control algorithms discussed in this thesis, is caused by the interaction of a manipulator with a stiff environment. Kinematics instability is present only in the hybrid control algorithm of Raibert and Craig, and is caused by the interaction of the inertia matrix with the Jacobian inverse coordinate transformation in the feedback path. Several methods were suggested and demonstrated experimentally to solve these stability problems. The result of the stability analyses were then incorporated in implementing a stable force/position controller on the direct drive arm by the modified resolved acceleration method using both joint torque and wrist force sensor feedbacks.

How to import files from your J drive into Teamsite

An update to Java meant that you can only import files into Teamsite from your 'My Documents' folder, which isn't much use if they are all stored on your J drive. This video shows you how to fix the problem.

A Brief History of the Web

The Web is now so ingrained in our lives that it is easy to forget that it is less than twenty years old. But the History of Web goes back much further, to the pioneering technologists who built the first hypertext systems and the men and women before them who imagined great libraries of interconnected information that would augment human intellect and drive civilization forward. In this lecture we will explore the pre-digital origins of the Web, look at how it developed into the mass communication system we have today, and speculate on the next stages of its evolution in the context of Web Science and Social Media.

Integración de APIs políglotas de mapas en Google Web Toolkit: IDELabMapstraction GWT

En este trabajo se ha integrado la librería IDELabMapstraction como un nuevo módulo para GWT, denominado IDELabMapstractionGWT, en el que también se han diseñado distintos controles genéricos que se pueden asociar al mapa para que los usuarios puedan interactuar con él de forma intuitiva. Como resultado de esta integración se ha creado el visor MirameDuero, un completo visor web realizado en colaboración con la Confederación Hidrográfica del Duero

GIS in the cloud: implementing a web map service on Google App Engine

Many producers of geographic information are now disseminating their data using open web service protocols, notably those published by the Open Geospatial Consortium. There are many challenges inherent in running robust and reliable services at reasonable cost. Cloud computing provides a new kind of scalable infrastructure that could address many of these challenges. In this study we implement a Web Map Service for raster imagery within the Google App Engine environment. We discuss the challenges of developing GIS applications within this framework and the performance characteristics of the implementation. Results show that the application scales well to multiple simultaneous users and performance will be adequate for many applications, although concerns remain over issues such as latency spikes. We discuss the feasibility of implementing services within the free usage quotas of Google App Engine and the possibility of extending the approaches in this paper to other GIS applications.

Forensisk undersökning av Solid State Drive

Solid State Diskar (SSD) är relativt nya och mycket om dem är okänt. Detta examensarbete fokuserar på att läsa forensiskt viktig information från både lagringsutrymmet och reservutrymmet. Detta har försökts genom att ett program har byggts i C++, detta program använder ATA kommandon för att läsa information från disken. Även om programmet aldrig blev färdigt kunde det skicka och ta emot data från en SSD, dock inte reservutrymmet vilket var fokus i detta examensarbete.