Search Results

As the spread of electric vehicles increases, tests to measure the driving distance on a single charge, which takes about 6 hours or more to completely discharge the battery, have become necessary. There is also a need to conduct tests using indoor alternative modes, such as real driving emissions (RDE) tests, which take about two hours. These tests can be said to be very harsh working environments because they take long periods of time on chassis dynamometer, and sometimes low-temperature tests are also required. In this study, basic research was conducted to enable a driving robot to perform long-term automobile performance tests on behalf of humans indoors using a chassis dynamometer. The final development goal is to develop a driving pedal robot that has an automatic calibration function suitable for various vehicles and has a shorter installation time than driving robots in the existing market.

In the whole world, emission regulations for vehicles with internal combustion engine have been dramatically strengthened to reduce air pollutions of urban area. Recently, SULEV and EURO-6 emission standard were applied to the gasoline and diesel vehicles in Korea, respectively. Therefore, emission characteristics on passenger car using gasoline including HEV and diesel fuel according to the various test modes were conducted in this study. In order to this investigation, exhaust emission characteristics of gasoline and diesel vehicles were measured and analyzed by using chassis dynamometer (Chassis dynamometer 48˝compact 2WD, AVL) and emission analyzer (MEXA-7000 series, Horiba). Test vehicles were selected the 3 domestic models of a car in Korea. For analysis on emission characteristics according to driving cycles including certification mode, NEDC, FTP-75 and WLTP modes was applied. From these results, it can be shown that all test vehicle models meet the emission standard.

This paper describes the effects of diverse driving modes and vehicle component characteristics impact on fuel efficiency and emissions of light commercial vehicles. The AVL's vehicle and powertrain system level simulation tool (CRUISE) was adopted in this study. The main input data such as the fuel consumption & emission map were based on the experimental value and vehicle components characteristic data (full load characteristic curves, gear shifting position curves, torque conversion curve etc.) and basic specifications (gross weight, gear ratio, tire radius etc.) were used based on the database or suggested value. The test database for two diesel vehicles adopted whether prediction accuracy of simulation data were converged in acceptable range. These data had been acquired from the portable emission measurement system, the exhaust emission and operating conditions (engine speed, vehicle speed, pedal position etc.) were acquired at each time step.

Under the present effort to decrease of air pollution, Electric Vehicles (EVs) are appeared and developed. EVs are running by using electrical energy resource by supporting of battery packs. The effect of air-conditioning has proven to be a serious problem to the point of battery depleting. Thus in the present study, effects of air conditioning (i.e., cooling and heating) on driving range were studied for various driving modes including UDDS, HWFET, and NEDC. The result shows that EV energy efficiency is opposing the usual trend of internal combustion engine vehicle's fuel consumption in highway driving mode than urban driving mode. In highway mode, EV energy efficiency and driving range also decease than urban driving mode. This status was influenced on motor characteristic which torque decrease in high speed rotating conditions and highway driving mode consist of constant speed velocity so it couldn't use the regenerative braking system effectively.

Turbocharged lean combustion was realized by using a multi-spark ignition device. The turbocharged lean operation in air-fuel ratio of 21:1 got the same torque level as the stoichiometric air-fuel ratio operation in naturally aspirated engine. For the turbocharged operation, NO and CO emissions remarkably reduced about 80 per cent and 85 per cent respectively and unburned HC increased about 30 per cent in condition of air-fuel ratio of 21:1 compared with stoichiometric air-fuel ratio. When compression ratio was increased, brake power and brake thermal efficiency increased and NO, CO and HC in exhaust emissions also increased. Combustion stability was estimated by using the coefficient of variation in indicated mean effective pressure. COVimep decreased when compression ratio was increased, but that value exceeded 10 per cent in low speed range. Accordingly, one of the important problems to be resolved in lean combustion is combustion stability in low speed range.