Engine Idling Research Articles

Spark Ignition Engine Idle Speed Control Using a Novel Framework and Enabling Control of the Tradeoff between Fuel Consumption and Load Rejection Capability

In this paper, a new framework for idle speed control is presented [The idle control methodology described paper is protected by international patent law]. A simple new discrete event based engine model evolving in the crank domain is given and is parameterized using a combination of dynamic identification and steady state calibration. The majority of the non-linearities can then be inverted and a second synthetic output is introduced. This second output is the torque reserve of the engine and enables control of the tradeoff between disturbance rejection capabilities and engine efficiency. A linear controller is designed using the H 8 loopshaping technique and results are presented from dynamometer based engine tests.

Indoor air quality at nine shopping malls in Hong Kong

Hong Kong is one of the most attractive shopping paradises in the world. Many local people and international tourists favor to spend their time in shopping malls in Hong Kong. Good indoor air quality is, therefore, very essential to shoppers. In order to characterize the indoor air quality in shopping malls, nine shopping malls in Hong Kong were selected for this study. The indoor air pollutants included carbon dioxide (CO 2), carbon monoxide (CO), total hydrocarbons (THC), formaldehyde (HCHO), respirable particulate matter (PM 10) and total bacteria count (TBC). More than 40% of the shopping malls had 1-h average CO 2 levels above the 1000 ppm of the ASHRAE standard on both weekdays and weekends. Also, they had average weekday PM 10 concentrations that exceeded the Hong Kong Indoor Air Quality Objective (HKIAQO). The highest indoor PM 10 level at a mall was 380 μg/m 3. Of the malls surveyed, 30% had indoor airborne bacteria levels above 1000 cfu/m 3 set by the HKIAQO. The elevated indoor CO 2 and bacteria levels could result from high occupancy combined with insufficient ventilation. The increased PM 10 levels could be probably attributed to illegal smoking inside these establishments. In comparison, the shopping malls that contained internal public transport drop-off areas, where vehicles were parked with idling engines and had major entry doors close to heavy traffic roads had higher CO and PM 10 indoor levels. In addition, the extensive use of cooking stoves without adequate ventilation inside food courts could increase indoor CO 2, CO and PM 10 levels.

A study of HC reduction with hydrocarbon adsorber systems

Hydrocarbon adsorber is considered as a promising technology to reduce cold start HCs in automotive exhaust gas. In this study, three in-line adsorber systems were tried to reduce the cold start emission. To check the basic characteristics of adsorber converters, surface areas, TPD and TPA were examined after a hydrothermal aging. Also idle engine bench was used to find the adsorption and desorption capabilities of the adsorber systems at cold start. Finally a practicability of the adsorber systems for the LEV achievement was checked with FTP test on a 2.0 D M/T vehicle. The results of this study indicate that hydrocarbon adsorber system is one of the promising passive technologies to meet the ULEV regulation.

Configuration and sizing design optimisation of powertrain mounting systems

A configuration and sizing design optimisation problem for powertrain mounting systems is formulated. The objective function is to decouple and maximise the component modal kinetic energy of the powertrain subsystem. Natural frequencies and collinear roll vector condition are used as the constraints. Cartesian coordinates and spring rates of the mounts are selected as the design parameters. An automated design optimisation procedure is developed using an optimisation code based on the method of feasible direction (MFD) and MSC/NASTRAN as a finite clement solver. The necessary gradient information is obtained using the central finite difference method. For the obtained optimum model, forced response analyses are performed in engine idling and wheel unbalancing conditions to show that overall accelerations are greatly reduced at the response positions.

Bronchoalveolar inflammation after exposure to diesel exhaust: comparison between unfiltered and particle trap filtered exhaust.

OBJECTIVES: Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells...

Adaptive fuzzy logic control of engine idle speed

The presented control scheme utilizes adaptive fuzzy logic to track a reference engine rotational speed during engine idling. The idle speed system is described and the non-linearity of the system and the presence of a variable time delay highlighted. To evaluate the performance of the controller a model of the system is developed and simulation results presented. Engine test results are also presented and compared with simulation results. It is shown that the Wang adaptive fuzzy logic algorithm is incapable of controlling systems with large time delays. This problem is solved in simulation using the Wang adaptive fuzzy logic algorithm in conjunction with the Smith prediction.

NARMAX modelling and robust control of internal combustion engines

Detailed in this paper is a SISO non-linear modelling and robust controller design methodology experimentally verified on an internal combustion engine. The methodology begins with the identification of a NARMAX model that captures the non-linear dynamics relating the input to the output of a system. This model is converted to a describing function representation for the purpose of robust feedback controller design. The ideology for the describing function recovery is developed in the form of an algorithm which can be extended to other NARMAX model structures not considered here. The controller design is executed in the frequency domain where the output performance specification is |y(t)|≤β∀t>0 and the actuator saturation constraint is |u(t)|≤K∀t>0. For the engine idle speed control application of this study, a SISO NARMAX model of the engine is developed between the by-pass idle air valve (BPAV) and engine speed. The performance objective for the controller design is the time domain tolerance of |Δ rpm| ≤ 100 rpm on idle speed perturbations despite a non-measurable 20 N m external torque disturbance. The controller is validated through numerical simulations as well as experimental verification.

Analysis on fuel economy and advanced systems of hybrid vehicles

Basic ideas on operation of hybrid vehicles were discussed from a view point of energy saving. Almost double fuel economy of series–parallel–hybrid vehicles was estimated on condition of no engine idling during vehicle stop, energy saving in acceleration using brake energy recovery and high efficiency operation on low load condition using series–hybrid system. From the discussion of overall efficiency, involving fuel cycle, under both low and high load conditions, both series–parallel–hybrid vehicles with internal combustion engine and fuel cell are supposed to have a high potential for the future.

The Optimum Designing of Engine Mounting for Heavy Duty Vehicle. 2nd Report, The Optimization of Coupled Vibration Reduction between Lateral and Rolling Mode.

The first paper described two important points concerning the reduction of engine idling vibration by theoretical approach. The first one was the lower resonance point of a rolling mode and the second one was to prevent a coupled vibration between a lateral and a rolling mode. This second paper shows the optimum design of a 6 mounting points engine model by FEM and the design of experiment, which is so called Taguchi methods. As the most important characteristic is tile lateral acceleration in C. O. G., which is the barometer of coupled vibration with rolling mode, the frequency response analysis is conducted to get it from 0 to 30Hz. As far as the optimization of 18 parameters is concerned, the 216 cases simulations are conducted by the allocation of L36 type orthogonal array. Even though the effect can be obtained by calculation, the bad test results are sometimes occurred by the errors. So, the error factors are also allocated to find out the useful parameters when errors are existing. Finally, nine effective parameters are found out. Among them, the mounting position changes to upward are the most effective. And moreover, by the reflection of the effective parameters, the engine mounting points can be reduced from six to four.

S.I. Engine Idle Assistance Using A Synchronous Machine: Experimental Results

This paper presents the experimental validation of an original way to improve idle of a spark-ignition engine. It is well known that inappropriate idle-speed control increases fuel consumption, pollutant emissions and also compromises stability. The solution proposed here has the distinctive feature of combining the traditional airflow rate control, simultaneously with the usual automobile alternator operating as a synchronous motor to provide a fast supplementary torque. This strategy is compared with the standard one in terms of stability, consumption and pollution.

Graphical Methods for Robust Design with Dynamic Characteristics

There has been considerable interest recently in the application of parameter design methodology to make a system's performance robust over a wide range of input conditions. This has been referred to as robust design with dynamic characteristics. In this paper, we first review this overall strategy and its usefulness and then demonstrate the limitations of the data analysis methods recommended by Taguchi. We then propose two graphical methods, the sensitivity-standard deviation plot and the gamma-plot, for identifying suitable measures of dispersion that are valid more generally. These graphical methods are related to the mean-variance plot and the lambda-plot that have been found useful in analyzing data from static robust design studies. The implementation and the usefulness of the proposed graphical methods are illustrated through two examples including a real application on engine idling performance.

S.I. Engine Idle Control Improvement by Using Automobile Reversible "Alternator"

This paper describes an original method for engine idle improvement. It is well known that inappropriate idle-speed control increases fuel consumption, pollutant emissions and also reduces the idle quality. To prevent engine stalling and improve its performance during idling it is proposed a strategy based on two control loops such as that of the traditional air-flow ratio and an other providing an external supplementary torque via the automobile's reversible "alternator". Hence engine stalling is prevented due to the faster torque response and secondly Fuel/Air ratio is easily controllable due to the slow variation of the intake air-flow.

Temperatures in a Gas Turbine Vaporizer at Near Idle Engine Conditions

The work is a laboratory investigation of the effect of different liquids and liquid flow rates on the metal temperature of a gas turbine T vaporizer. Most of the experimentation was carried out using JP5. A limited number of runs using Diesel Fuel Marine and calibration runs using water provided additional data for different fluids. Conditions that approach local liquid depletion inside the vaporizer were identified by monitoring local overheating of the vaporizer metal. Because of apparatus limitations, testing was carried out only at vaporizer pressure and liquid flow rates approaching idle engine operation. An experimental correlation was developed allowing estimation of the mean vaporizer temperature as a function of input conditions and fluid properties.

Flow analysis of engine cooling system for a passenger vehicle

A numerical simulation is carried out to analyze the flow field of cooling air through the radiator and engine compartment. In order to consider the strong effect of the suction-type flow by the cooling fan at engine idling condition, a potential flow analysis is attempted by the assumption of a line sink located at the position of the cooling fan. The governing equations for steady two-dimensional, incompressible, turbulent flow are solved with the two-equationk-e model for turbulence. The velocity profiles in the underhood engine compartment and around the front-end of a real vehicle are measured to compare with the numerical results. The agreement between the numerical and experimental results is fairly good. It is concluded that a two-dimensional computation is a fast and efficient tool for predicting the effect of front-end design on the cooling air flow through the radiator.

Fuzzy logic control of an automotive engine

A systematic fuzzy logic control design method for control of automotive engine idling speed is discussed. The method uses the direct intelligent control paradigm. The procedure is based on partitioning of the state space into small rectangles called cell groups, and quantization of the states and the available controls into finite levels or bins. Membership functions are then assigned for the state and controls. The transition from one conditional subspace to another is accomplished via a center-point mapping of the cell groups, under the applied action of each if-then rule. The systematic aspects of the procedure refer to the way transitional elements are clustered on the basis of an explicitly defined performance measure. Optimum transitions are selected using a search procedure. The fuzzy rules are generated automatically for transitioning from any initial cell group to the target cell group. A simplified engine model for idling speed control is used as the testbed for development and demonstration purposes. >

Contribution of fuzzy logic control to the improvement of modern car performances

After a short introduction to the Fuzzy control, this paper presents an overview of the applications for which this new control technique is used to improve the performance of modern cars. These applications are: 1. a. Engine Idle Speed, 2. b. Automatic Transmission, 3. c. Cruise controller, 4. d. Anti-Knock control system. A quick overview is given on the applications (a),(b),(c), proposed by different car manufacturers and described in Abate (1990), Takahashi (1989) & (1990). More attention will be paid to the application (d). This study confirms the advantages of using a fuzzy logic controller, in particular for its good properties in terms of robustness, in addition with easy design and implementation.

A study of a fire on a diesel railcar

A fire broke out on a diesel railcar while running on a line of the Japan Railways Group. After an exhaustive investigation into the cause of the fire, it was found that the origin had been the lubricating oil of the engine. The lubricating oil vaporized from a long idling engine while the car was standing and accumulated in the exhaust silencer in considerable amounts. When the car was climbing up a long slope, the oil was exposed to a high-temperature exhaust gas and ignited. The flame attacked and melted the exhaust funnel, and eventually caused a fire.

Laboratory testing of a gas turbine vaporizer

A laboratory test apparatus was constructed for assessing the metal temperature and the state of different airfuel mixtures at the outlet of a gas turbine vaporizer fuel injector. The performance of the apparatus was according to the imposed requirements for idle engine operation. Fuels tested were JP5, JP7, and Diesel Fuel Marine. Data consisted of vaporizer metal temperatures, inlet and exit mixture temperatures, as well as power input to the vaporizer. Photographic observations of the exit mixture showed that the liquid phase consisted of droplets, ligaments, as well as irregularly shaped particles originating as pendant droplets around the vaporizer exit. There was no observable difference between the results for JP5 and JP7. The liquid exit temperature, however, for these two fuels appeared to be lower than that for the diesel fuel. The computed extent of vaporization was in qualitative agreement with the experimental observations.

The influence of ambient temperature on tailpipe emissions from 1985 to 1987 model year light-duty gasoline motor vehicles—II

Tailpipe emissions from gasoline fieled motor vehicles are sensitive to a number of factors including driving schedule (speed vs time), ambient temperature and fuel composition. The sensitivity of hydrocarbon (HC), aldehyde, CO, and oxides of nitrogen (NO x ) emissions to these variables was examined with 11 recent technology (1985–1987 model year) four- six- and eight-cylinder gasoline fueled motor vehicles. In excess of 200 individual HCs and 12 aldehydes were included in the detailed organic emission characterizations. Two fuels and driving schedules were used. Hydrocarbon and CO emissions increased significantly and NO x emissions, in general, increased slightly as ambient temperature decreased. Formaldehyde also increased only slightly at test temperature decreased. Paraffin and aromatic emission fractions were dependent on fuel composition with olefin fraction being less fuel sensitive. When the low temperature cold start was preceded by a 5 min engine idle, CO and HC emissions were lowered, and NO x emissions essentially unchanged.

The influence of ambient temperature on tailpipe emissions from 1984–1987 model year light-duty gasoline motor vehicles

Motor vehicle emissions are sensitive to a number of variables including ambient temperature, driving schedule (speed vs time) and fuel composition. Hydrocarbon (HC), aldehyde, CO and oxides of nitrogen ( NO x ) emissions were examined with nine recent technology 4-cylinder gasoline motor vehicles at 21.1°C (70°F), 4.4°C (40°F), and −6.7°C (20°F). About 200 HC and 12 aldehyde compounds were included in the organic emissions characterization. Two fuels and two driving schedules were used. Typically, HC and CO emissions were significantly increased by reduced ambient temperature. NO x emissions also increased, but to a lesser extent. There were no predictable formaldehyde emissions trend with temperature. Paraffins and aromatic HC emission fractions were sensitive to fuel composition, but the olefinic emission fraction (dominated by ethylene and propylene) was not. With low temperature cold start tests, preceding driving with a 5 min engine idle resulted in reduced CO emission rates and elevated NO x emission rates. HC emission rates were not predictably sensitive to the preliminary idle.