In the weaving industry a variety of meshes are manufactured, using both metallic and nonmetallic materials, for a wide variety of filtration applications. At present the quality of the mesh is monitored at several st...
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In the weaving industry a variety of meshes are manufactured, using both metallic and nonmetallic materials, for a wide variety of filtration applications. At present the quality of the mesh is monitored at several stages of the manufacturing process to keep selected parameters within specified limits. This involves stopping the process approximately every half hour, manually assessing the mesh quality, and taking remedial action as necessary. There is a need to replace these manual checks with an automatic system that can continually monitor the mesh as it is being manufactured and, with appropriate actuators, control the loom on-line. The authors present initial results of research being conducted at Sheffield University to develop such a system for wire mesh. Early experiments proved that a contact measurement technique is inappropriate due to the severe vibrations and backlash nonlinearities present in most looms. The approach adopted here therefore, is to use image processing techniques. The instrument is transputer based so that the image processing can be performed on several processors to achieve the real-time performance necessary for on-line monitoring and control purposes.< >
System simulation involves the construction of a computational analogue of a physical system-a process which has traditionally been associated with intemperate demands on processing time. This is more true today than ...
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System simulation involves the construction of a computational analogue of a physical system-a process which has traditionally been associated with intemperate demands on processing time. This is more true today than ever before. Complex large-scale plant simulators and process mimics are almost commonplace in some high-technology industries. In such settings, simulation may be used in both the design and validation of novel control strategies, as well as forming part of an operator training programme, or in cause-consequence diagnostics. The problem arises that as physical systems evolve in complexity, the dimensionality of the underlying dynamical equations can rise dramatically, creating an immense computational burden at simulation time. Often this may result in the violation of any real-time constraints, and the effects may become so acute as to render computer times that are excessive to the point of impracticality. Consequently, the authors are concerned with the development of parallel methodologies for such problems. Attention is focused on a necessarily restricted set of large-scale systems (LSS): those that are adequately described by high-dimensional sets of ordinary differential equations (ODE's) in state-space form. It should be noted however, that many of the general concepts relating to parallelism exploitation, extend to a much wider class of problems.< >
An ever increasing amount of map data for the world's land masses is held in digital format. The computational demands of producing images in an acceptable time can be met by using high performance and low cost pa...
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An ever increasing amount of map data for the world's land masses is held in digital format. The computational demands of producing images in an acceptable time can be met by using high performance and low cost parallelprocessing machines so that new algorithms can be rapidly prototyped and tested. Such an approach has been made feasible by the use of transputer systems. There are a number of conventional algorithms which take digital surface data and process it to produce the required images. Most current algorithms are inherently sequential and do not, in general, map easily onto parallel processor architectures. The authors show that by careful algorithm design the problem can be mapped onto a number of processors by exploiting the fact that a calculation for one area is not dependent on any other data manipulations other than its own and hence can proceed independently. The algorithm is based on ray casting.< >
Concerns a project developing an architecture for a mobile factory robot, the GEC Turtle. This vehicle, which measures 0.9*1.2 m with a platform 0.6 m high, is equipped with a variety of sensors including sonar, trino...
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Concerns a project developing an architecture for a mobile factory robot, the GEC Turtle. This vehicle, which measures 0.9*1.2 m with a platform 0.6 m high, is equipped with a variety of sensors including sonar, trinocular stereo and a sophisticated laser range finder. The architecture is to be applicable to certain other vehicles. A distributed transputer architecture is adopted for sensing and control. The transputer provides a powerful on-board facility and adapts easily to a distributed reconfigurable sensing and control strategy. A generic transputer architecture for sensors with local intelligence allows the building of networks of distributed sensors and opens an integrated path for combining the information of disparate sensors. In control, a distributed architecture overcomes the bottlenecks associated with a centralised controller. The use of transputers throughout gives a consistent interface for easy communication and interfacing between the various units in the sensing and control strategy.< >
Describes a demonstrator project investigating the use of parallelprocessing in fault-tolerant gas turbine engine control undertaken by Dowty controls. The vehicle for this work is the Inmos transputer. As a multiple...
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Describes a demonstrator project investigating the use of parallelprocessing in fault-tolerant gas turbine engine control undertaken by Dowty controls. The vehicle for this work is the Inmos transputer. As a multiple processor architecture is to be used there is inherent redundancy within the system and the aim of this work is to try and exploit this redundancy to introduce fault tolerance into the system while efficiently utilising the processing power available. A system simulator is under development which uses multiprocessor arrays. This simulator allows engine and controller simulations to be operated in closed-loop and allows different fault tolerant strategies and dynamic reconfiguration to be investigated. A user interface is used to alter system parameters during operation and for inducing failures in the system. Among the concepts being investigated are load balancing, dynamic scheduling, fault detection and recovery strategies.< >
The Inmos transputer has stimulated significant interest in parallelprocessing for control. It offers real-time implementation of complex algorithms at a reasonable cost but if parallelarchitectures are to be fully ...
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The Inmos transputer has stimulated significant interest in parallelprocessing for control. It offers real-time implementation of complex algorithms at a reasonable cost but if parallelarchitectures are to be fully exploited it is essential that systematic mapping procedures emerge from the application specific solutions presently under consideration. The paper proposes two different mapping procedures. One relies on a fine-grained systolic array description of computation and is applied to transputer realisation of discrete Kalman filters for state feedback control of a simple missile engagement. The other uses an analogue computer flow diagram to produce a real-time simulation of a bank-to-turn missile. In each case practical results have been obtained.< >
Although optimal control techniques provide, in theory, the ability to design suitable control strategies for general control problems, in practice the results are not commonly implemented due to the large computation...
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Although optimal control techniques provide, in theory, the ability to design suitable control strategies for general control problems, in practice the results are not commonly implemented due to the large computational requirements for solving such problems. A recent development in computer systems has been the use of parallelprocessing techniques to speed up computations by sharing the work load over several processors that can interact between each other for message passing, sharing variables etc. In particular the advent of the INMOS transputer with its unique serial links have opened the doors to true parallelism in computer systems and much applications research is currently underway that is aimed at using transputer arrays. An area of interest to the authors is automatic flight control, which could also benefit from the introduction of parallelprocessing. In the paper the authors present two parallel optimal control algorithms for aircraft systems.< >
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