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A liquid phase LPG injection (LPLi) system has been considered as one of the next generation fuel supply system, since it has a very strong potential to accomplish the higher power, higher efficiency, and lower emission characteristics than the mixer type that is classified as a second generation technology, whereas the LPLi system is classified as a third generation technology. However, when a liquid LPG fuel is injected into the inlet duct of an engine, a large quantity of heat is extracted due to its high latent heat of evaporation. This leads the moisture in the air to freeze around the nozzle exit, which is called icing phenomenon. It may cause damage to the outlet nozzle of an injector or inlet valve seat. In this work, the experimental investigation of the icing phenomenon was carried out. The results showed that humidity of air rather than the temperature of air in the inlet duct mainly controlled the icing process.

Since the emission gap of nitrogen oxides between the measurements in the indoor emission certification test and the driving in real road conditions has revealed to be significant, the RDE(Real Driving Emissions) regulations of exhaust emissions in real road driving in Europe were adopted in 2017 at the Euro 6d-TEMP stage and gradually strengthened thereafter. Many countries including Korea are applying equivalent and similar regulations. In order to identify whether vehicles in use comply with the emission standards within the exhaust emissions warranty period, it is necessary to add real road tests to ongoing in-use inspections. Thus, a study on the development of an indoor test cycle in order to use for in-use inspection instead of an real road test becomes required while satisfying RDE criteria.

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.