Search Results

Electronic control units (ECUs) offer a modular, networked approach to real time machine control and diagnostics. Software embedded in these controllers offer agile and customizable solutions because of the intimate relationship with the ECU hardware and its inputs/outputs. In an idealistic view, embedded software should support the machine's life - 30 years or longer. Developing and maintaining software for these systems requires a strategy. A framework demonstrating common building blocks and long-term centralized support for ECUs on a machine is presented. This strategy reduces the detailed knowledge of the specific machine controls needed by ECU developers and provides the components and infrastructure key to extending the life and functionality of the ECU.

The testing system developed will decrease the time and the costs involved in evaluating cylinder head valve bridge designs. The test uses actual data generated from engine testing to recreate the valve bridge cracks that occur during dynamometer and vehicle testing. This paper focuses on the system description, the test development, design modifications, and the test results obtained. Testing shows that this method correctly separates valve bridge designs by test cycle life using statistical methods. It is a cost effective and timely alternative to dynamometer testing.

This paper introduces research work on 1-D model of Roots type supercharger with helical gears using 1-D simulation tool. Today, passenger car engine design follows approach of downsizing and the reduction of number of engine cylinders. Superchargers alone or their combination with turbochargers can fulfill low-end demands on engine torque for such engines. Moreover, low temperature combustion of lean mixture at low engine loads becomes popular (HCCI, PCCI) requiring high boost pressure of EGR/fresh air mixture at low exhaust gas temperature, which poses too high demands on turbocharger efficiency. The main objective of this paper is to describe Roots charger features and to amend Roots charger design.

A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage.

An advanced low heat rejection engine concept has successfully completed a 100 hour endurance test. The combustion chamber components were insulated with thermal barrier coatings. The engine components included a titanium piston, titanium headface plate, titanium cylinder liner insert, M2 steel valve guides and monolithic zirconia valve seat inserts. The tribological system was composed of a ceramic chrome oxide coated cylinder liner, chrome carbide coated piston rings and an advanced polyolester class lubricant. The top piston compression ring Included a novel design feature to provide self-cleaning of ring groove lubricant deposits to prevent ring face scuffing. The prototype test engine demonstrated 52 percent reduction in radiator heat rejection with reduced intake air aftercooling and strategic forced oil cooling.

Aerospace structures manufacturers find themselves frequently engaged in large-scale 3D metrology operations, conducting precision measurements over a volume expressed in meters or tens of meters. Such measurements are often done by metrologists or other measurement experts and may be done in a somewhat ad-hoc fashion, i.e., executed in the most appropriate method according to the lights of the individual conducting the measurement. This approach is certainly flexible but there are arguments for invoking a more rigorous process. Production processes, in particular, demand an automated process for all such “routine” measurements. Automated metrology offers a number of advantages including enabling data configuration management, de-skilling of operation, real time input data error checking, enforcement of standards, consistent process execution and automated data archiving. It also reduces training, setup time, data manipulation and analysis time and improves reporting.

Many automated guided golf cars using the electromagnetic guide technology are used in Japan to obtain more convenient and safer golf play. Now this technology is beginning to be used outside of the golf course as an on-demand people mover system. This paper presents an example of the engineering system of automated guided golf cars along for the 2 principles of automated guided vehicle. The first principle is “the steering control system including the automatic sensitivity adjustment function”, and the other principle is “the vehicle speed control system”.

A vehicle model is an important factor in the development of vehicle control systems. Various vehicle models having different complexities, assumptions, and limitations have been developed and applied to many different vehicle control systems. A 14 DOF vehicle model that includes a roll center as well as non-linear effects due to vehicle roll and pitch angles and unsprung mass inertias, is developed. From this model, the limitations and validity of lower order models which employ different assumptions for simplification of dynamic equations are investigated by analyzing their effect on vehicle roll response through simulation. The possible limitation of the 14 DOF model compared to an actual vehicle is also discussed.

Transfer path analysis is a powerful tool to support the vehicle NVH development. On the one hand it is a fast method to gain an overview of the complex interplay in the vehicle noise generation process. On the other hand it can be used to identify critical noise paths and vehicle components responsible for specific noise phenomena. FEV has developed several tools, which are adapted to the considered noise phenomena: Powertrain induced interior noise and vibration is analyzed by VINS (Vehicle Interior Noise Simulation), which allows the deduction of improvement measures fast enough for application in the accelerated vehicle development process. Further on vehicle/powertrain combinations not realized in hardware can be evaluated by virtual installation of the powertrain in the vehicle, which is especially interesting in the context of engine downsizing from four to three or six to four cylinders.

The experience accumulated with a prototype 1000 HP diesel electric tractor since 1969 is described. The new 1500 HP V220 diesel electric tractors are described along with some of the initial operation of these two units. Experience with the initial 1000 HP unit and the two 1500 HP tractors confirm the necessity of additional testing and experimentation to refine the design to get greater productivity with reduced operator fatigue. The unpredictability of the load and operating surface are major problems that present a real challenge to the engineer.

Direct fuel injection is becoming mandatory in two-stroke S.I. engines, since it prevents one of the major problems of these engines, that is fuel loss from the exhaust port. Another important problem is combustion irregularity at light loads, due to excessive presence of residual gas in the charge, and can be solved by charge stratification. High-pressure liquid fuel injection is able to control the mixing process inside the cylinder for getting either stratified charge at partial loads or quasi-stoichiometric conditions, as it is required at full load. This paper shows the development of this solution for a small engine for moped and light scooter, using numeric and experimental tools. In order to obtain the best charge characteristics at every load and engine speed, different combustion chambers have been conceived and studied, examining the effects of combustion chamber geometry, together with injector position and injection timing

CHEVROLET has made its new air-suspension system easily interchangeable in production line assembly with standard full-coil suspension by adopting a 4-link-type rear suspension with short and long arms. A feature of the system is the mounting of the leveling valves within the air-spring assemblies. These valves correct riding height continually at a moderate rate, regardless of whether the springs are leveling or operating in ride motion. The system provides constant frequency ride—ride comfort remains the same whether the car is occupied by the driver alone or is fully loaded.

This paper deals with some recent advances in the field of 1D fluid dynamic modeling of unsteady reacting flows in complex s.i. engine pipe-systems, involving a catalytic converter. In particular, a numerical simulation code has been developed to allow the simulation of chemical reactions occurring in the catalyst, in order to predict the chemical specie concentration in the exhaust gas from the cylinder to the tailpipe outlet, passing through the catalytic converter. The composition of the exhaust gas, discharged by the cylinder and then flowing towards the converter, is calculated by means of a thermodynamic two-zone combustion model, including emission sub-models. The catalytic converter can be simulated by means of a 1D fluid dynamic and chemical approach, considering the laminar flow in each tiny channel of the substrate.

The introduction of more stringent standards for engine emissions requires a steady development of exhaust gas aftertreatment in addition to an optimized cylinder combustion. The reduction of the cold start phase can help significantly to lower cycle emissions. With the goal of optimizing the overall emission performance this study presents a comprehensive simulation approach. A well established 1D gas dynamics and engine simulation model is extended by three key features. These are models for combustion and pollutant production in the cylinder, models for the pollutant conversion in a catalyst, and a general species transport model. This allows to consider an arbitrary number of chemical species and reactions in the entire system.

This paper presents 1D engine simulation used for engine control strategy optimization for a twin-scroll turbocharged gasoline direct injection 2.0 L engine with twin camphaser. The results show good agreement of the engine model behavior with testbed acquisitions for a large amount of steady state set points and under transient operating conditions. The presented method demonstrates that a 1D engine code represents a useful and efficient tool during all steps of the engine control development process from design to real-time for such an advanced engine technology.

This paper describes the development and application of the 1D thermo-fluid dynamic research code GASDYN to the simulation of a Lamborghini 12 cylinder, V 60°, 6.2 L automotive S.I. engine. The model has been adopted to carry out an integrated simulation (thermodynamic, fluid dynamic and chemical) of the engine coupled to its intake and exhaust manifolds, in order to predict not only the wave motion in the ducts and its influence on the cylinder gas exchange process, but also the in-cylinder combustion process and the pollutant emission concentration along the exhaust system. The gas composition in the exhaust pipe system is dictated by the cylinder discharge process, after the calculation of the combustion via a thermodynamic multi-zone model, based on a “fractal geometry” approach.