Stephen Quayle

Just-in-Time Continuous Flight Auger Piles Using an Instrumented Auger

Continuous flight auger (CFA) piles are constructed by drilling a CFA auger into the ground and, on reaching the required depth, pumping concrete down the hollow stem as the auger is steadily withdrawn. Current practice to predict the bearing capacity of CFA piles is to estimate the undrained shear strength-depth relationship for the overall site, and use a total stress analysis to predict a general pile bearing capacity. This analysis is often based on sparse site data collected from a location remote from the pile. This paper investigates the exploitation of new technology to enable a new improved approach to the procurement, design and validation of (CFA) bored piles. The ultimate target is that the final length of the piles will be determined on site, as they are constructed, and will be optimised to suit the actual local ground conditions.

Data interpretation from Leuze RotoScan sensor for robot localisation and environment mapping.

Two applications for the use of a laser-scanning device are currently under investigation at Lancaster University. Lancaster University Computerised Intelligent Excavator (LUCIE) is an autonomous excavator which navigates using GPS and compass readings. Work is currently concentrating on navigational safety, for which the rotoscan sensor is employed for obstacle detection, and for possible self-localisation and environment comprehension in ambiguous operational states. Starlifter is a robotic arm built by Construction Robotics Ltd. The rotoscan sensor in this instance is to be mounted on the tool head and used as a final positioning navigation tool. Both these applications rely heavily on the interpretation of the received data, and the ability to filter out any interference. This paper initially outlines the mode of utilisation of the laser range finder within such applications and then proceeds to investigate the implications and potential limitations of such a sensor following the analysis of the sensory data from external field trials.

System Architectures and Safety for Mobile Construction Robots

This paper describes the most recent work on the development of the autonomous robot excavator LUCIE 2 at Lancaster . Although the LUCIE project (Lancaster University Computerised Intelligent Excavator) has been running for about five years , in recent months it has undergone a radical change in both system hardware and software . This has come about as a result of research sponsored by the UK Safety Critical Systems Programme , which has highlighted the problems of producing a well argued safety case for intelligent robots in unstructured environments . Other changes have resulted from the automation of the vehicle tracks which means that LUCIE 2 is fully mobile for the first time. Work is also progressing on the problem of linking the robot excavator to project CAD drawings , and this is briefly discussed in the paper. The new developments discussed in the paper include : the use of three individual ultra-compact PC 104 computer systems, communication between computers using CAN bus , the use of a new scanning laser sensor to detect possible collisions , and the use of a satellite global positioning system for excavator positioning and navigation. Recent developments in GPS technology now mean that the vehicle can be reliably positioned to an accuracy of 25 mm.

Safe Systems Architectures for Autonomous Robots

This paper describes work we have carried out in the development of a control system for an autonomous robot excavator. We describe some specific problems which complicate the development of safe systems for autonomous vehicles. We then go on to discuss how we developed an understanding of the hazards of vehicle operation and describe the architecture of the excavator control system. In this architecture, all system actions are moderated by a safety management sub-system. This system checks all movements against a set of potentially hazardous situations and information from independent sensor systems. Potentially dangerous actions are curtailed or corrected by the safety manager. We also discuss the trade-offs which must be made between safety and economic viability in this type of machine and suggest some areas where we believe that further research is necessary.

A BASIC DESIGN-BUILD-TEST EXPERIENCE: MODEL WIND TURBINE USING ADDITIVE MANUFACTURE

This paper describes a project undertaken by most first-year Engineering undergraduates at Lancaster University in which they are set the task to design, build and test a scale-model wind turbine.

On Site Pile Instrumentation and its Integration into the Management Process

The paper describes how modern computer and telecommunications technology has enabled the creation of a piling instrumentation system that integrates seamlessly with the rest of the site and project management processes. The system, called SIRIS, consists of an industrial computer and sensors on the piling rig, a notebook computer used by the site foreman and a database system located back at the office all of which are linked by GSM (Global System for Mobile Communications) modems.

Some Experimental Force Analysis for Automation of Excavation by a Backhoe

Automating the excavation function of an excavator is a complex control problem, because of the nature of the interaction between the cutting tool and the medium and the many parameters that are involved in the process. A fundamental question that is not yet resolved is the choice of parameters to be used in a feedback loop for the control of the process, and the control algorithm. Based on a previous proposition for the control algorithm to be used for this purpose, knowledge about the forces involved may be used for adjusting the motion of the bucket. In this paper, some results of experimental measurements of the excavation forces are presented. These forces cannot be measured directly on the bucket, but the kinematic and dynamic relations can serve for this purpose. The paper talks about the development of these relations, and then the results are presented and discussed.