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Current emission control systems utilize a catalytic converter employing a three-way catalyst (TWC), composed of a mixture of noble metals to minimize the three main pollutant classes of NOx, CO, and HC. The TWC is most efficient when the air-to-fuel ratio (A/F) is at stoichiometry (i.e. A/F ≈ 14.7). The stoichiometric set-point region is maintained by the use of oxygen sensors composed of the solid-electrolyte yttria stabilized zirconia (YSZ) in an electronic feedback loop. As combustion gets leaner a different exhaust sensor can be utilized to give a measure of the level of pollutants. A NOx sensor is an alternative for an oxygen sensor that can be used for feedback control of engine combustion or exhaust NOx traps. A solid electrolyte disk composed of YSZ having two Pt electrodes with one being covered by a microporous zeolite material was tested as a sensor for combustion produced gases such as NO and NO2 in the presence of O2.

Legislation pertaining to automobile emissions has caused an increased focus on the cold-start performance of internal combustion engines. Of particular concern is the period of time before all available sensors become active. Present engine control strategies must rely on methods other than feedback control while these sensors are not active. Without feedback control during this critical period, engine emissions performance is not optimized. These conditions cause difficulty in performing comprehensive cold-start experiments. For these reasons, we have developed several methods for feedback control during cold-start to aid in laboratory investigations of engine emissions phenomena.

We consider a vehicle-roadway system where the control of vehicle movement is based on the instrumentation located both in the vehicle and the roadway. In addition to the sensors which are used for obtaining the information on the vehicle, a radar based sensor system is used for providing information on the position of the car relative to a vehicle ahead, and with respect to a reflective strip placed on the road. The roadway traffic includes standard vehicles with no automatic control as well as the vehicles with automatic control units. Communication between the vehicles is not considered. For longitudinal control, we consider an Radar Based Cruise Control problem where the main goal is to maintain a desired speed set by the driver. At the same time, the controller will decelerate the vehicle if the distance and/or the relative speed between the controlled vehicle and the vehicles traveling in front are below certain limits.

In this paper, we propose an IC engine fuel system diagnostic algorithm based on a discrete-event nonlinear observer using the production oxygen sensor. A mean value engine model is used to describe the engine dynamics. A procedure for designing the discrete event based observer is presented and applied to estimate important engine variables using the measured binary oxygen sensor output. The estimated variables are then used to perform diagnostics of the fuel system of the IC engine. Experimental results on a multi-cylinder production engine are presented to demonstrate the effectiveness of the proposed method.

This paper begins with a discussion of the various types of risk behavior found in automobile driving. A model is proposed which describes a perceptual approach to risk acceptance in specific driving manuevers. Risk acceptance in lane merging within freeway construction zones is discussed and exemplified by field observations of merging in construction zones. The short gaps accepted led to an experimental study to examine gap acceptance thresholds and driver gap estimation capabilities. Studies were conducted both staticly and dynamicly at 55 miles per hour. Subjects elect short gaps (under 100′) and gaps with less than 1 3/4 seconds at 55 miles per hour. Shorter rear gaps are accepted than front gaps. Gaps are grossly underestimated in both static and dynamic experiments. No difference was found for left vs. right merges and use of mirror vs. direct vision for rear gap estimation. The experimental data was consistent with field observations.

Assuming rigid body motion, recorded acceleration and recorded roll rates at the center of gravity, equations are used to calculate the local three-dimensional accelerations at hypothetical seating positions' Emergency Locking [seat belt] Retractors (ELR) during a steer induced rollover crash. For a threshold of 0.7 g, results demonstrated that intervals in the vehicle's response that may cause the ELR's inertial sensor to move into a neutral zone were limited to localized high magnitude negative vertical acceleration events during the rollover segment with a median duration of 4 ms, average duration of 4.8 ms and a maximum calculated duration of 31.7 ms. Changing the threshold to 0.35 g reduced the interval count by 70 percent and maximum duration by approximately 50 percent.