Multiplexed solutions to integrate the onboard electronics in the city-bus vehicles
The electrical circuits and installations in buses and coaches are essential for their good working. Drive, braking, suspension, opening door, security and communication systems depend on the electrical system of the vehicle. The disproportionate length of cable (about 4 Km of cables and 100 Kg of weight in a conventional installation), with more of 2,000 connections per vehicle, generates great difficult and the point-to-point links are not an effective solution. The industrial communication networks or fieldbuses are a multiplexed solution for onboard electronics in the public transport buses and coaches. The authors are working in the design and implementation of new modules based on FPGAs (Field Programmable Gate Arrays) to integrate body and chassis functions in the multiplexed solutions from manufacturers.
A Reconfigurable Communication Processor Compatible with Different Industrial Fieldbuses
Fieldbuses constitute the lower level of communication networks in a flexible manufacturing system. Nowadays there are a lot of proprietary protocols, thus the interconnection of equipment from different manufacturers has become very problematic. Changing equipment supposes the change of the fieldbus too with the consequent economic losses. This paper proposes the implementation of a communication processor based on a reconfigurable device that makes different fieldbuses compatible. In this way, using the appropriate level and impedance matching circuit, the same hardware can be connected to different fieldbuses. In order to verify this proposal a communication processor based on an FPGA supporting two very important fieldbus standards in the area of industrial control such as WorldFIP and Profibus, has been developed. Design constraints and performance of the implemented processor are analyzed in this paper.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.