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Condensable and gaseous hydrocarbon emissions and speciation of the hydrocarbons have been investigated using a EURO1 emissions compliant SI (Spark Ignition) car. Exhaust gas samples were simultaneously collected upstream and downstream of the catalyst using a system containing cold ice trap, resin, particulate filter block and Teflon gas sampling bag. GC (Gas Chromatography) was employed to analyze for hydrocarbons and 16 of the more significant hydrocarbons are reported. The test was carried out using both cold start and hot start driving cycles. Results show that the benzene and toluene were major species emitted from the tailpipe under cold start conditions. Methylnaphthalene was a dominated hydrocarbon under hot start conditions. The cold start had significant influence on hydrocarbon emissions. The catalyst out benzene emissions for cold start was thirty times higher than that for hot start.

An in-vehicle FTIR emission measurement system was used to investigate the exhaust emissions under different real world urban driving conditions. Five different driving cycles were developed based on real world urban driving conditions including urban free flow driving, junction maneuver, congested traffic and moderate speed cruising. The test vehicle was a EURO 2 emission compliant SI car equipped with temperature measurement along the exhaust pipe across the catalyst and real time fuel consumption measurement system. Both regulated and non-regulated emissions were measured and analyzed for different driving cycles. All journeys were started from cold. The engine warm up features and emissions as a function of engine warm up for different driving conditions were investigated.

An on-board emission measurement system (PEMS), the Horiba OBS 1300, was installed in Euro 1-4 SI cars of the same model to investigate the impact of vehicle technology on exhaust emissions, under urban driving conditions with a fully warmed-up catalyst. A typical urban driving loop cycle was used with no traffic loading so that driver behavior without the influence of other traffic could be investigated. The results showed that under real world driving conditions the NOx emissions exceeded the legislated values and only at cruise was the NOx emissions below the legislated value. The higher NOx emissions during real-world driving have implications for higher urban Ozone formation. With the exception of the old EURO1 vehicle, HC and CO emissions were under control for all the vehicles, as these are dominated by cold start issues, which were not included in this investigation.

The effect of flow direction towards the spark plug electrodes on ignition parameters is analyzed using an innovative spark aerodynamics fixture that enables adjustment of the spark plug gap orientation and plug axis tilt angle with respect to the incoming flow. The ignition was supplied by a long discharge high energy 110 mJ coil. The flow was supplied by compressed air and the spark was discharged into the flow at varying positions relative to the flow. The secondary ignition voltage and current were measured using a high speed (10MHz) data acquisition system, and the ignition-related metrics were calculated accordingly. Six different electrode designs were tested. These designs feature different positions of the electrode gap with respect to the flow and different shapes of the ground electrodes. The resulting ignition metrics were compared with respect to the spark plug ground strap orientation and plug axis tilt angle about the flow direction.

Human steering intervention is an important factor for the safety and control performance of autonomous vehicles. Accurate identification of human steering torque will enable human drivers to take over the controls from the autonomous driving system whenever they require or intend to. However, in the take-over process, both the human driver and actuator motor will apply active torques simultaneously on the steering wheel, thus the human torque cannot be detected by using a torque sensor due to the coupled torques. Therefore, effective estimation though the system dynamics can be an alternative measure to achieve the detection and a comparatively accurate quantification of the human steering intervention torque. In this paper, an online estimation strategy of human steering intervention torque for the steering actuation system of an autonomous vehicle is presented. The dynamic model of the steering actuation system is firstly established.

Different driving test cycles, the Leeds-West Park (LWP) loop and the Leeds-High Park (LHP) or HPL-A and B (Leeds-Hyde Park Loop-A or B, hereafter referred as HPL-A or B cycle) loop were selected for this urban intersection research and results are presented in this study. Different emissions-compliant petrol passenger cars (EURO 1, 2, 3 and 4) were compared for their real-world emissions. A reasonable distance of steady state speed was needed and for the analysis made in this paper were chosen vehicle speeds at ~20, ~30 and ~40 km/h. Specific spot of periods of driving at the speeds mentioned above were identified, then the starting and ending point was found and the total emissions in g for that period divided by the distance was calculated. A typical urban driving cycle including a loop and a section of straight road was used for the comparison test as it was similar to the legislative ECE15 urban driving cycle.

The Carbon Dioxide (CO₂) emission from a EURO 3 diesel van over a real-world driving cycle were investigated utilizing part of the Leeds University - Headingly Ring Road (LU-HR) driving cycle, which comprises both an urban (congested) and extra-urban (high speed) driving section. The vehicle used in this research was a 1.8-liter Ford Connect TDCi diesel van. Emissions were monitored by a Portable Emissions Measurement System (PEMS) incorporating an on-board FTIR (Fourier Transform Infrared) exhaust emission measurement system, a Horiba On Board emissions measuring System (OBS 1300) which measured the exhaust flow rate and air/fuel ratio, and a RaceLogic VBOX II differential GPS system provided geographical position, speed and acceleration data. Route topography is known to have substantial influence on vehicle emission.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined for urban congested traffic conditions. In UK cities cold-starting vehicles directly into congested traffic conditions is a common occurrence that is not currently taken into account when modeling urban traffic pollution. In-vehicle emission samples were taken directly from the exhaust, upstream and downstream of the catalyst, using the bag sampling technique. The first bag was for the cold start emissions and approximately the first 1.1 km of travel. The following three bags were with a hotter catalyst. The cold start tests were conducted over a year, with ambient temperatures ranging from 2°C to 30°C. The results showed that CO emissions for the cold start were reduced by 70% downstream of the catalyst when the ambient temperature rose from 2°C to 30°C. The corresponding hydrocarbon emissions were reduced by 41% and NOx emissions were increased by 90%.

Tumble motion plays a significant role in modern spark-ignition engines in that it promotes mixing of air/fuel for homogeneous combustion and increases the flame propagation speed for higher thermal efficiency and lower combustion variability. Cycle-by-cycle variations in the flow near the spark plug introduce variability to the initial flame kernel development, stretching, and convection, and this variability is carried over to the entire combustion process. The design of current direct-injection spark-ignition engines aims to have a tumble flow in the vicinity of the spark plug at the time of ignition. This work investigates how the flow condition changes in the vicinity of the spark plug throughout the late compression stroke via high-speed imaging of a long ignition discharge arc channel and its stretching, and via flow field measurement by particle imaging velocimetry.

As the world searches for ways to reduce humanity’s impact on the environment, the automotive industry looks to extend the viable use of the gasoline engine by improving efficiency. One way to improve engine efficiency is through more effective control. Torque-based control is critical in modern cars and trucks for traction control, stability control, advanced driver assistance systems, and autonomous vehicle systems. Closed loop torque-based engine control systems require feedback signal(s); indicated mean effective pressure (IMEP) is a useful signal but is costly to measure directly with in-cylinder pressure sensors. Previous work has been done in torque and IMEP estimation using crankshaft acceleration and ion sensors, but these systems lack accuracy in some operating ranges and the ability to estimate cycle-cycle variation.

Oil migration has a great impact on vapor compression systems, especially for automobile air conditioning systems which require frequent on-off cycling without sufficient oil management inside the compressor. Excessive amounts of oil retained in the system and lack of oil returned to the compressor can cause low system efficiency and potential compressor failure. This paper explores and quantifies the transient effects in oil migration and property changes at the compressor suction and the discharge. Oil flow behavior and oil migration are quantified and analyzed by the high-speed camera recording and optical method at the compressor discharge and the liquid line under different compressor startup speeds and on-off frequencies. The flow under cold and warm startup conditions is studied and compared. The oil-refrigerant mixture flow at the suction and discharge during cold startup transitions from two-phase flow to vapor refrigerant flow and oil annular mist flow.