Current Issue : July - September Volume : 2016 Issue Number : 3 Articles : 4 Articles
The computer simulation of the Common Rail accumulator fuel-injection system was carried out. The computer\nsimulation enables the observation of the phenomena from rail pressure, which is input data for injection parameters\ncalculation, to the injection rate. By means of computer simulation, the pressure values in specific sections of the\ninjection nozzle may be computed, the needle lift, injection rate, total injected fuel, time lag from injector current to\nfirst evidence of injection process and others time lags between various phases of injection process.\nMeasurements of injection and combustion were carried out in a transparent research engine. This engine is a single cylinder\ntransparent engine based on the AUDI V6 engine, equipped with a Bosch Common Rail Injection System.\nThe optical part of the experimental setup contains two different lasers, while the camera system allows for\nsimultaneously detecting 4 signals: the Mie scattering of the injected fuel, the laser-induced fluorescence (LIF) of fuel\nand vapour, light emissions from the flame indicating the premixed combustion mode, and flame emissions indicating\nthe diffusion mode.\nThe comparison of the computed and measured injection parameters showed good matching....
In hybrid electric vehicles with power-split configurations, the engine can be decoupled\nfrom the wheel and operated with improved fuel economy, while the entire efficiency of the\npowertrain is affected by the circular electric power flow. Two planetary gear (2-PG) sets with\nadding brakes/clutches, namely a type of four shaft elelctric continuously variable transmission\n(ECVT) can provide multi-mode operation for the powertrain and extend the efficient area. First,\na conventional 2-PG AT (Automatic Transmission) architecture is investigated. By analyzing and\ncomparing the connection and operating modes based on the kinematic relationship and lever analogy,\na feasible four-shaft ECVT architecture with two brakes and two simplified versions are picked. To\nmake a trade-off between fuel economy and configuration complexity, an instantaneous optimal\ncontrol strategy based on the equivalent consumption minimization strategy (ECMS) concept is then\ndeveloped and employed as the unified optimization method in the simulations of three different\nconfigurations. Finally, the simulation results show that the simplified versions are suboptimal\nsets and the fuel economy is sacrificed by the limits of different modes. From the viewpoint\nof concept design, a multi-mode power-split configuration is more suitable for hybrid electric\nvehicles. This research applied a systematic methodology from concept design to energy management\noptimization, which can provide the guidelines for researchers to select a suitable multi-mode\npower-split hybrid powertrain....
This paper discusses the design of dynamic curvature steering control for\nautonomous vehicle. The lateral control and longitudinal control are discussed in this paper.\nThe controller is designed based on the dynamic curvature calculation to estimate the path\ncondition and modify the vehicle speed and steering wheel angle accordingly. In this paper, the\nsimulation results are presented to show the capability of the controller to track the reference\npath. The controller is able to predict the path and modify the vehicle speed to suit the\npath condition. The effectiveness of the controller is shown in this paper whereby identical\nperformance is achieved with the benchmark but with extra curvature adaptation capabilites....
The problem of initial instability of rear-wheel braking on cars is presented in this paper. The analysis of the\nbraking transient process was performed, with computer simulation of the two different cases of wheel suspension:\nan existing one and a new proposed concept. Presented below is the behaviour of the rear wheels during braking,\nwhere the force of the wheel pressing the ground surface appears as a key parameter. The conclusion is that the\nexisting concept, with backward oriented oscillating suspension arm, has a natural imperfection as regards a quality\nof adhesion of the wheel with the ground surface. The new proposed concept of the wheel suspension is given. The\nresult of analysis shows that the natural stability of braking could be improved with the new concept, independently\nof existence of ABS (anti-lock braking system) on the car....
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