Jasper Graham-Jones

FirstLight: Pluggable Optical Interconnect Technologies for Polymeric Electro-Optical Printed Circuit Boards in Data Centers

The protocol data rate governing data storage devices will increase to over 12 Gb/s by 2013 thereby imposing unmanageable cost and performance burdens on future digital data storage systems. The resulting performance bottleneck can be substantially reduced by conveying high-speed data optically instead of electronically. A novel active pluggable 82.5 Gb/s aggregate bit rate optical connector technology, the design and fabrication of a compact electro-optical printed circuit board to meet exacting specifications, and a method for low cost, high precision, passive optical assembly are presented. A demonstration platform was constructed to assess the viability of embedded electro-optical midplane technology in such systems including the first ever demonstration of a pluggable active optical waveguide printed circuit board connector. High-speed optical data transfer at 10.3125 Gb/s was demonstrated through a complex polymer waveguide interconnect layer embedded into a 262 mm × 240 mm × 4.3 mm electro-optical midplane. Bit error rates of less than 10-12 and optical losses as low as 6 dB were demonstrated through nine multimode polymer wave guides with an aggregate data bandwidth of 92.8125 Gb/s.

A robotic welding system using image processing techniques and a CAD model to provide information to a multi‐intelligent decision module

Purpose – The paper aims to propose a system that uses a combination of techniques to suggest weld requirements for ships parts. These suggestions are evaluated, decisions are made and then weld parameters are sent to a program generator.Design/methodology/approach – A pattern recognition system recognizes shipbuilding parts using shape contour information. Fourier‐descriptors provide information and neural networks make decisions about shapes.Findings – The system has distinguished between various parts and programs have been generated so that the methods have proved to be valid approaches.Practical implications – The new system used a rudimentary curvature metric that measured Euclidean distance between two points in a window but the improved accuracy and ease of implementation can benefit other applications concerning curve approximation, node tracing, and image processing, but especially in identifying images of manufactured parts with distinct corners.Originality/value – A new proposed system has bee...

Improving ability of tele‐operators to complete progressively more difficult mobile robot paths using simple expert systems and ultrasonic sensors

– The purpose of this paper is to describe the use of simple expert systems to improve the performance of tele‐operated mobile robots and ultrasonic sensor systems. The expert systems interpret data from the joystick and sensors and identify potentially hazardous situations and then recommend safe courses of action so that tele‐operated mobile‐robot tasks can be completed more quickly., – The speed of a tele‐operator in completing progressively more complicated driving tasks is investigated while using a simple expert system. Tele‐operators were timed completing a series of tasks using a joystick to control a mobile robot through a simple expert system that assisted them with driving the robot while using ultrasonic sensors to avoid obstacles. They either watched the robot while operating it or sat at a computer and viewed scenes remotely on a screen from a camera mounted on the robot. Tele‐operators completed tests with the simple expert system and the sensors connected. The system used an umbilical cable to connect to the robot., – The simple expert systems consistently performed faster than the other systems. Results are compared with the most recently published results and show a significant improvement. In addition, in simple environments, tele‐operators performed better without a sensor system to assist them but in more complicated environments than tele‐operators performed better with the sensor systems to assist., – Simple expert systems are shown to improve the operation of a tele‐operated mobile robot with an obstacle avoidance systems fitted., – Tele‐operated systems rely heavily on visual feedback and experienced operators. This paper investigates how to make tasks easier. Simple expert systems are shown to improve the operation of a tele‐operated mobile robot. The paper also suggests that the amount of sensor support should be varied depending on circumstances., – The simple expert systems are shown in this paper to improve the operation of a tele‐operated mobile robot. Tele‐operators completed tests with the simple expert system and the sensors connected. The results are compared with a tele‐operator driving a mobile robot without any assistance from the expert systems or sensors and they show a significant improvement.

Expert system to interpret hand tremor and provide joystick position signals for powered wheelchairs with ultrasonic sensor systems

Purpose – The purpose of this paper is to investigate how to make powered‐wheelchair driving easier using simple expert systems to interpret joystick and ultrasonic sensor data. The expert systems interpret shaky joystick movement and identify potentially hazardous situations and then recommend safe courses of action.Design/methodology/approach – The way that a human user interacts with a powered‐wheelchair is investigated. Some simple expert systems are presented that interpret hand tremor and provide joystick position signals for an ultrasonic sensor system. Results are presented from a series of timed tasks completed by users using a joystick to control a powered‐wheelchair. Effect on the efficiency of driving a powered‐wheelchair is measured using the times to drive through progressively more complicated courses. Drivers completed tests both with and without sensors and the most recently published systems are used to compare results.Findings – The new expert systems consistently out‐performed the most...

Embedded planar glass waveguide optical interconnect for data centre applications

Electro-optical printed circuit boards (EOCB) based on planar multimode polymer channels are limited by dispersion in the step-index waveguide structures and increased optical absorption at the longer telecom wavelengths [1]. We present a promising technology for large panel EOCB based on holohedrally integrated glass foils. The planar multimode glass waveguides patterned into these glass foils have a graded-index structure, thereby giving rise to a larger bandwidthlength product compared to their polymer waveguide counterparts and lower absorbtion at the longer telecom wavelengths. This will allow glass waveguide based EOCBs to support the future bandwidth requirements inherent to large scale data centre and high performance computer subsystems while not incurring the same dispersion driven penalties on interconnect length or loss dependence on wavelength. To this end glass foil structuring technologies have been developed that are compatible with industrial PCB manufacturing processes. Established processes as well as new approaches were analysed for their eligibility and have been applied to the EOCB process. In addition a connector system has been designed, which would allow optical pluggability to glass waveguide EOCBs.

Simple rules to modify pre‐planned paths and improve gross robot motions associated with pick & place assembly tasks

Purpose – This paper aims to describe real time improvements to the performance and trajectories of robots for which paths had already been planned by some means, automatic or otherwise. The techniques are applied to industrial robots during the gross motions associated with pick and place tasks. Simple rules for path improvement are described.Design/methodology/approach – The dynamics of the manipulator in closed form Lagrange equations are used to represent the dynamics by a set of second‐order coupled non‐linear differential equations. The form of these equations is exploited in an attempt to establish some simple rules. Sub‐optimal paths are improved by considering simple rules developed from the model of the machinery dynamics. By considering the physical limitations of the manipulator, performance was improved by refining pre‐calculated paths. Experiments were performed with a prototype robot and an old Puma 560 robot in a laboratory environment. Once the method had been tested successfully then exp...

Polymer optical waveguides with reduced in-plane bend loss for electro-optical PCBs

In-plane bend loss represents the greatest commercial inhibitor to deploying multimode optical waveguides on densely populated electro-optical printed circuit boards (OPCB) as the minimum bend radii currently possible are too large to be practical in common designs. We present a concept and fabrication method for creating novel polymer optical waveguide structures with reduced bend losses to enable higher density routing on an OPCB. These nested core waveguide structures comprise a core surrounded by a thin shell of cladding, which allows for two-fold modal containment by first a conventional low refractive index contrast (LIC) boundary followed by a secondary high refractive index contrast (HIC) boundary. The purpose of this is to reduce the in-plane bend losses incurred on tightly routed optical channels, while not incurring prohibitive dispersion, sidewall scattering and optical crosstalk penalties. We have designed and fabricated nested core multimode polymer waveguides, evaluated their performance in comparison to conventional step-index waveguides and simulated these structures using the beam propagation method. Preliminary results are presented of our measurements and simulations

Eco-friendly Flax Fibre/Epoxy Resin/Composite System for Surfboard Production

A commercially available eco-friendly epoxy resin is proposed as the matrix for a flax fibre composite surfboard as a potential “sustainable” material for component production. The study develops a method for robust production of the surfboards using flax fibre and bio-epoxy resin. The objective of the work is to achieve a balance between economical product, low weight, mechanical performance, improved impact resistance and (outside of this paper) improved environmental credentials. This study seeks to achieve a complete mechanical and thermal characterisation of the flax/eco-epoxy system as an alternative material system to a conventional S-glass/polyester system. For this reason, both systems are completely characterised and their properties compared.

Application of composite materials to yacht rigging

The rigging of sailing vessels has always evolved to take advantage of the best materials available at the time. Standing rigging on a sailing boat are the tension members (lines, wires or rods) which normally remain in constant position while the vessel is under way. Running rigging are those elements which are moved whilst the boat is sailing to raise, lower and control the sails. The progression from natural fibre ropes through steel wire and rod rigging has now led to composite materials being used for rigging. In addition to looking at the history of this development, this chapter discusses the design requirements of modern yacht rigging and describes the composite materials which are currently used for this purpose.