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The crankshaft position sensor (CPS) is a variable reluctance magnetic sensor which accurately senses the position of four teeth equally spaced 90° apart on a toothed ring attached to the crankshaft. The electronic engine control (EEC) calculates RPM using two adjacent pulses, and with other processed information, calculates spark advance. Actual spark initiation again uses the CPS as a reference position. The properties and environment of the sensor which determine accuracy, noise, and other characteristics important in its interface with the system is discussed.

An experimental sensor has been developed to indicate the air-fuel ratio of an engine operating on lean mixtures. Stabilized zirconia doped with iron was used as the sensor electrolyte. These sensors are internally temperature compensated, eliminating the need for additional temperature sensing or electronics. Sensor output is responsive to exhaust oxygen content, but is independent of exhaust temperatures above 450°C at 18:1. Addition of iron increased uniformity of output among sensors.

WITH THE DEVELOPMENT of the Ford Electronic Engine Control System to meet increasing emission and fuel economy requirements, the need arose to accurately assess engine coolant and inlet air temperatures in order to properly control exhaust gas recirculation flow and spark timing. This paper will discuss the design of the temperature sensors developed for that purpose. The sensors meet the functional requirements of the control system and are durable and reliable. The basic design is also readily adaptable to many other temperature sensing applications.

This paper describes the application of automotive sensors to electronic control of the internal-combustion engine, with emphasis on sensor-signal characteristics and utilization. Manifold absolute pressure, crankshaft position, throttle position, temperature, and exhaust-gas recirculation are among the parameters monitored to electronically regulate engine inputs. Also presented are a number of control concepts realized with these sensors.

The use of microprocessors in automotive electronics systems such as Electronic Fuel Injection (EFI) and Electronic Fuel Management (EFM) has created a need for a variety of precision position-sensors capable of reliable performance in underhood environments. This paper describes the basics of precision potentiometers and switches which have been adapted for these and other specialized engine applications. A brief description introduces the precision potentiometer as a position-sensor, and details the differences among the more common types of potentiometers. The fundamental low cost position-sensor concept is elaborated upon with a discussion of some of the special materials and techniques used to develop units for automotive applications. Among the special problems discussed are requirements of long life at high temperature, high vibration environment, and stringent performance accuracy.

The Wiegand Effect is a new magnetic phenomenon occurring in a specially work-hardened small diameter ferro-magnetic wire. When subjected to an appropriate magnetic field, a sudden, very rapid flux change occurs. A substantial voltage pulse may be induced in a sensing coil wound around the Wiegand wire, or in its proximity. No electrical input is required, and with the appropriate excitation the pulse is essentially independent of the rate of flux change of the externally applied field. The characteristics of the Wiegand Effect are of interest in a number of automotive applications.

The paper presents an overview of developments on the principal sensors applicable to automotive engine control through brief descriptions of the more important sensor concepts for the various parameters, and an indication of sensor status. The parameters covered are manifold absolute pressure (MAP), manifold vacuum (MV), ambient absolute pressure (AAP), crankshaft position (speed), mass air flow, fuel flow, coolant temperature, air temperature, oxygen partial pressure, and throttle position. Special sections are included covering sensor developments overseas, and describing noteworthy efforts of the SAE and the International Standards Organization (ISO) with respect to engine sensor standards.

Experimental work was done with a Texaco stratified-charge engine to investigate the effect of fuel type, spark timing, and fuel injection timing on efficiency and emissions. Gasoline, diesel fuel, and a mixture of the two in equal proportions were used as fuels. The mixture of gasoline and diesel fuel simulates a broad-boiling-range fuel, referred to as “broadcut fuel.” Data were taken during full-load and part-load operations; the part-load operation simulated road-load conditions for a 3,000-lb vehicle. Results show engine efficiency ranges from about 20% at light-load to over 30% at full-load. The difference in efficiency attributable to fuel type was one to two percent. Between the two fuels gasoline and diesel, greater efficiency was associated with diesel fuel at part-load while the greater efficiency at full-load was seen with gasoline.

Cycle by cycle variations in combustion are investigated as a means to characterize the lean misfire limit of a spark ignited, internal combustion engine. The cyclic variations are represented as parameters of the cylinder pressure versus crankangle curves. The specific parameters investigated are peak pressure, maximum rate of pressure rise, crankangle of maximum pressure, crankangle of maximum rate of rise, indicated mean effective pressure, and area of the pressure curve. The variations are statistically analyzed on a digital computer. Exhaust gas analysis is performed to determine the correlation between the misfire limit and emissions of hydrocarbons, carbon dioxide, carbon monoxide, nitric oxide, and formaldehyde. Imep and area variations are found to be the most promising as an indicator of the lean misfire limit. As the equivalence ratio decreases from stoichiometric, the variations stay constant, until a sharp linear increase is achieved.

The economy van has evolved through three generations of design changes. From a full-forward control, primarily commercial vehicle first introduced in the U.S. in 1954, it has grown into a semi-forward control vehicle that is now used in a wide range of business and personal applications. Sales will exceed 700,000 units in 1977. The versatility of the original compact closed body design has been enhanced by higher GVW's, larger engines, and improved driver environment to meet growing customer requirements. The future challenge will be to preserve essential functional characteristics while significantly improving fuel economy.

Spectroscopical investigations of the combustion process in spark ignition engines have been performed by aid of the band head of the OH-band system at 306.4 nm. Using an optical probe system the course of the emission-absorption-temperatures and OH-concentrations at different combustion chamber positions could be detected. The experimental results are related to those calculated by use of a theoretical model describing the change of the thermodynamical and chemical state of the gas. Additional measurements were executed at a combustion chamber of constant volume.

One solution to the estimation of product reliability during the development phase is to measure reliability improvement over time and compare this improvement (growth) to previous product development progress. This paper uses the Duane's reliability growth model and applies it to some subsystems of light duty trucks during their design and development and prototype testing. The data presented illustrates explicitly the prediction of the reliability growth during development and testing. The data is used to estimate the parameters for the reliability growth curve. Once the model is developed, it can be used to monitor product reliability.

This paper describes the performance and emissions of a hydrogen-fueled, spark-ignited engine. An electronic control device, designed to provide the engine with a timed injection of the fuel, is shown to give high mean effective pressures and high efficiencies. The oxides of nitrogen from the exhaust gases have been analyzed and the mechanism for their formation is reviewed. The paper further describes an experiment with traces of hydrocarbons added to the hydrogen in an attempt to explain any additional phenomena that may be taking place during the combustion, such as “prompt NO” which is known to occur in hydrocarbon flames only. As it turns out, such additions have a negligible effect on the NOx formation in the region investigated.

Single-cylinder spark ignition engine experiments conducted at constant speed, fixed airflow, and using isooctane as the fuel, demonstrated the effects of fuel-air mixture preparation on lean operation. Mixture preparation was changed by varying the time of fuel injection in the induction manifold, near the intake valve port. For comparison, a prevaporized fuel-air mixture was also investigated. Emphasis was placed on determining the effects of mixture preparation on combustion characteristics. Based on the results from this study, the often favored prevaporized mixture of fuel and air may not be the best diet for lean engine operation.

The concentration of pollutants in the combustion space of an indirect injection swirl diesel engine have been studied on a time basis. A fast acting water-cooled gas sampling valve was used for the in-cylinder sampling. The measured concentrations have been used to visualise a simplified reaction zone structure of diesel combustion. The results show that carbon monoxide appears first in the reaction zone followed by nitric oxide and soot. The high soot concentration exists only for a short period of time (3 ms) and is rapidly reduced to a low level whereas carbon monoxide is gradually oxidised to carbon dioxide over the expansion cycle. The reaction zone is found to be 10-20mm wide and is widest near the chamber wall.

A method of rapidly removing and quenching more than 75% of the cylinder content of a running diesel engine has been developed and tested. The resulting data give total nitric oxide in the cylinder versus crankangle. The data show that nitric oxide forms rapidly reaching a peak value in 20° CA or less. For higher loads and advanced timing the concentration overshoots the exhaust value by 14% before decreasing to the exhaust value. A few comparisons are made between the data and four existent models.

A study of fluid mechanical effects on unburned hydrocarbon generation has been made in a single compression-expansion model automobile engine. Full optical access has allowed color schlieren observations of gas motion inside the engine cylinder. Motion pictures of the gas motion and flame propagation have been taken at a rate of seven thousand frames per second for the following cases: 1) intake stroke 2) exhaust stroke 3) compression power stroke with combustion and blow-down with appropriate exhaust valve opening. Unburned fuel concentrations were measured by means of a gas chromatograph. The results show that turbulent motion of the mixture increases the amount of unburned fuel. It is implied that the rolled-up vortices play an important role on wall flame quenching processes in an engine.

Diesel Odor sampling and analysis techniques and procedures using the Arthur D. Little, Inc. Diesel Odor Analysis System (DOAS) have been evaluated. Reproducibility of ± 0.1 TIA unit at the 2.0 TIA level and ± 0.2 TIA unit at the 1.5 TIA level are achievable if a consistent, well defined sampling procedure is used. Significant odor sample trap breakthrough and sample volume effects have been isolated. This study indicates that care must be given to defining a standard odor sampling configuration and procedure.

With the aid of static mixer and non-ionic emulsifying agent, a comparatively stable water-fuel emulsion was obtained. Engine performance in a 4 cycle direct injection engine using these fuels were studied. A large reduction of NOx concentration was obtained over the wide range of engine operation, in spite of increased ignition lag and rapid combustion. Furthermore, improvements of economy and reduction of exhaust smoke were obtained. The reduction of NOx concentration, fuel consumption and smoke were even more remarkable when compared with operating same engine with water fumigation.

A multi-zone model is developed to predict the rate of heat release in direct injection diesel engines. By considering the complete air-fuel jet mixing process and temperature dependent reaction rates in each zone, the model also enables subsequent spacial and temporal history of burning rate, local temperature and air-fuel ratio etc. to be calculated. It is shown that the model is capable of predicting realistic rate of pressure rise and heat release rates and responds sensibly to changes in injection timing, swirl ratio and air temperature.