Extracting Vehicle Trajectories from Partially Overlapping Roadside Radar.

This work presents a methodology for extracting vehicle trajectories from six partially-overlapping roadside radars through a signalized corridor. The methodology incorporates radar calibration, transformation to the Frenet space, Kalman filtering, short-term prediction, lane-classification, trajectory association, and a covariance intersection-based approach to track fusion. The resulting dataset contains 79,000 fused radar trajectories over a 26-h period, capturing diverse driving scenarios including signalized intersections, merging behavior, and a wide range of speeds.

Two-color pyrometry system to eliminate optical errors for spatially resolved measurements in flames.

Two-color (2C) pyrometry has long been used to measure flame temperature and soot concentration from radiative emission in flames. While 2C pyrometry is not an absolute measurement in non-axisymmetric flames (such as diesel spray combustion), it is a desirable diagnostic for semi-quantitative or qualitative measurements since it requires minimal optical access and can utilize high-speed imaging to attain exceptional temporal and spatial resolutions. In this work, an improved optical configuration of 2C pyrometry is presented that (1) eliminates optical errors inherent in other designs and (2) uses off-the-shelf optics and a single camera.

Phase boundary detection in transient, evaporating high-pressure fuel sprays by rainbow schlieren deflectometry.

The rainbow schlieren deflectometry (RSD) technique is used to simultaneously identify the liquid and vapor boundaries during transient evolution of evaporating high-pressure fuel sprays. Traditionally, liquid and vapor phases require separate diagnostics, whereas this work relies upon a single technique to identify each phase, in addition to the previously demonstrated capability of RSD to measure local fuel-air mixing in the vapor zone. The proposed RSD methodology is a significant improvement over a previously published technique, i.

Quantifying liquid boundary and vapor distributions in a fuel spray by rainbow schlieren deflectometry.

The rainbow schlieren deflectometry (RSD) technique is used to determine the liquid boundary and the fuel volume fraction distributions in the vapor region of a high-pressure fuel spray. Experiments were conducted in a constant pressure flow vessel, whereby a customized single-hole common-rail diesel injector is used to introduce n-heptane fuel into a coflow of low-speed ambient air at two different test conditions. Only the quasi-steady period of the fuel spray is considered, and multiple injections are performed to acquire statistically significant data at an image acquisition rate of 20 kHz.