This paper describes a prototype of an automatic behavioural synthesis system targetted at FPGA-based reconfigurable digital systems. Experiment with the system, especially for synthesising random number generators, s...
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This paper describes a prototype of an automatic behavioural synthesis system targetted at FPGA-based reconfigurable digital systems. Experiment with the system, especially for synthesising random number generators, shows that register-transfer level hardware costs do not reflect hardware costs in terms of FPGA resource (e.g. Xilinx CLBs). This shows that extensive efforts that have been spent in the past for optimizing RTL-hardware costs need be reconsidered. For this particular example, a simple register allocation (i.e. no register allocation at all) is much better than register allocation based on the left-edge algorithm. Experiments in synthesising random number generators involving both FPGAs and RAMs also shows that behaviourally-equivalent circuits with the same number and types of RTL-hardware units require different number of CLBs.
The authors present an investigation into the utilisation of parallel computing techinques for real-time simulation and control of a flexible beam structure in transverse vibration. The performance demands of modern c...
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The authors present an investigation into the utilisation of parallel computing techinques for real-time simulation and control of a flexible beam structure in transverse vibration. The performance demands of modern control systems require the employment of complex algorithms with demanding operations which, in turn, leads to shorter sampling times. Therefore, real-time performance in control applications where the use of advancedcontrol methods is warranted becomes difficult to accomplish. Many demanding complex control processes cannot be satisfactorily realised with conventional uni-processor and multi-processor systems. Previous investigations have demonstrated the limitations of employing only transputers for real-time implementations in control applications. Alternative strategies where multi-processor based systems are employed, utilising digital signal processing (DSP) and parallel processing techniques, could provide suitable methodologies.< >
Real-time control systems are considered as possibilities to come to a better utilization of the urban and interurban networks. It was decided to implement such a system in Nijmegen in order to assess the traffic perf...
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ISBN:
(纸本)085296613X
Real-time control systems are considered as possibilities to come to a better utilization of the urban and interurban networks. It was decided to implement such a system in Nijmegen in order to assess the traffic performance of an on-line optimized real-time control system against the existing control system. This paper describes the implementation and plans for evaluation of SCOOT in Nijmegen. It was explicitly decided not to develop a new real-time control system, but to consider the possibilities and applicability of an existing system. The SCOOT system was chosen because it's an operational system, successfully applied in the United Kingdom and other countries, and still under development. Failures are rare. The communication lines are in good condition and detectors are operating well. The interfaces with the existing controllers appear to be quite good. Since the SCOOT system came in operation, it didn't require much attention which is good. There are no complaints from public transport and police. The gating appears to operate well. The system is able to deal with high traffic loads.
There is an automatic Incident Detection System based image processing techniques. Image are provided to the system by video cameras monitoring the traffic along the motorways. Outputs are alarms triggered when an inc...
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ISBN:
(纸本)085296613X
There is an automatic Incident Detection System based image processing techniques. Image are provided to the system by video cameras monitoring the traffic along the motorways. Outputs are alarms triggered when an incident is detected or traffic measurement values. The system is known as the local module of the INVAID System. This paper reports and discusses the results obtained during field trials carried out in these 3 test-beds. Tests made on 3 different sites have shown very satisfactory results of video automatic incident detection INVAID system. They can be summarized as follows: detection rate 84 to 91% with optimized installation;false alarm rate of 6 to 13%;false alarm frequency of 0.02 to 0.26 per day per camera;mean time to detect equal to the threshold used, typically 15 seconds. performance of the system depends of field installation factors. Experience gained from the tests made allows to draw conclusions on this issue;for example, detection rate is maximized with characteristics such as: high mounted cameras, rigid poles, field of view close to the pole, long field of view (camera using long focal length). Guidelines are being prepared on the ground of INVAID experiments so that infrastructures operators will be able to design their own system and have some idea in advance about its likely performance.
A distributed computer containing DSP devices as the computational elements is presented. The computer is based on multiple processor modules (TM5320CXX series), interconnected via a time division multiplexed transput...
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A distributed computer containing DSP devices as the computational elements is presented. The computer is based on multiple processor modules (TM5320CXX series), interconnected via a time division multiplexed transputer link channel to a central control unit. Some simulation performance results for the communication mechanism are also presented.< >
Current implementations of aircraft flight control systems are an amalgam of numerous, discrete algorithms and various switching mechanisms. The switching mechanisms bring the algorithms into play either independently...
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Current implementations of aircraft flight control systems are an amalgam of numerous, discrete algorithms and various switching mechanisms. The switching mechanisms bring the algorithms into play either independently or in some form of combination. advancedcomputing techniques, such as expert systems, can play a role by separating out the algorithm scheduling and making it more visible. By lessening the complexity both the integrity and capability should be improved. An alternative and more controversial approach is to use adaptive, learning and optimisation techniques such as neural networks. These offer advantages by removing the need for algorithm creation through learning, provide graceful degradation when elements fail and can adapt to subsystem failures. However at present this approach is not welcomed as conventional verification and validation techniques cannot be employed. The author discusses the role of non-algorithmic software.< >
System availability is of primary interest to a wide variety of compute-intensive application areas, such as scientific and financial modelling, air traffic management, medical computing, and process control. Traditio...
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System availability is of primary interest to a wide variety of compute-intensive application areas, such as scientific and financial modelling, air traffic management, medical computing, and process control. Traditionally, this has been achieved by replicative fault-tolerance, but this is grossly expensive. The advent of the transputer has provided the opportunity for use of techniques employed in local area networks to migrate down into more tightly-coupled computing systems. The paper describes the development and transputer implementation of an alternative to replicative fault-tolerance which offers not only high-availability, high-performancecomputing, but also features lower cost, graceful degradation, and the potential for use in safety-critical environments.< >
A canard-controlled missile airframe configuration with a twist-and-steer (or polar) control system affords economies in design and kinematic performance but at present does not permit a direct analytical solution for...
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A canard-controlled missile airframe configuration with a twist-and-steer (or polar) control system affords economies in design and kinematic performance but at present does not permit a direct analytical solution for the optimum guidance and roll control autopilot laws. The development of a stable roll loop of adequate bandwidth and response is fundamental in a twist-and-steer missile. Whilst the application of modern control theory has been successfully applied to the design of aileron-constrained time-invariant cases, its extension to the nonlinear case requires further development. Roll loop design is commonly carried out using frequency-domain methods coupled with detailed mathematical modelling and digital simulation. The use of commercially available control system design programs facilitates loop design and sensitivity studies across the operating envelope. Describing function techniques may be used to investigate limit cycle stability etc. The paper discusses the aerodynamics and the computer-aided design.< >
The three principal military high speed data bus standards are Draft Proposal STANAG 3910, SAE AS 4074.1 Linear Token Passing Bus and AS 4074.2 high Speed Ring Bus. There is a significant difference between 3910 and t...
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The three principal military high speed data bus standards are Draft Proposal STANAG 3910, SAE AS 4074.1 Linear Token Passing Bus and AS 4074.2 high Speed Ring Bus. There is a significant difference between 3910 and the SAE standards, in that 3910 makes use of the existing STANAG 3838 (Mil Std. 1553B) to control access to a high speed (20 Mbit/sec) channel. In meeting the needs of time critical systems the only difference between 3910 and 1553B is the message length that can be transmitted within the latency bounds of 1553B. Nevertheless, 3910 has a number of significant advantages for near term and retro-fit applications. In particular, the tried and tested practice of co-siting the data communications control function with the controlling system element can be retained; the way in which communications and systems control is to be achieved with truly general purpose high speed data buses such as those produced by SAE is yet to be resolved.< >
The Conceptual And Relational Database System is a knowledge-based server for very large knowledge-based applications supported by a highperformance relational database. control of the CARDS engine is maintained by a...
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The Conceptual And Relational Database System is a knowledge-based server for very large knowledge-based applications supported by a highperformance relational database. control of the CARDS engine is maintained by a conceptual model interpreter which provides knowledge-based programs with a high level modelling language that supports inference and consistency checking through constraint propagation within a network of inter-related concepts. The project includes the development of a large scale knowledge-based system which provides intelligent support to molecular biologists and cancer research scientists in the analysis and prediction of protein structures from gene and amino acid sequences.< >
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