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In gear condition monitoring, it is often impractical to measure the vibrations directly at or close to their sources. It is common practice to measure the vibration at a location away from the source due to the limitation of accessing to the machine to be monitored. The vibration measured in this way inevitably has high distortions from the vibrations due to the effect of the attenuation of signal paths and the interference from other sources. Suppressing these distortions to obtain useful information is a key issue for remote measurement based condition monitoring. This paper develops a new feature designed for remote gear damage diagnosis based on advanced signal processing. Time synchronous average (TSA) is firstly used to suppress the random noise and interferences. Then Continuous Wavelet Transformation (CWT) of TSA signals is obtained to enhance the fault characteristics.

The emission characteristics of compression ignition (CI) engines running on biodiesel during transient operating conditions, which is the most usual case in urban and extra-urban transportation, have rarely been investigated. In the present study an experimental investigation on emission characteristics of a CI engine has been carried out both under steady state and transient operating conditions. The experimental work has been carried out on CI engine, which is integrated with transient testing facility. This facility is capable of varying the engine speed and load over a given time period. To measure the engine emissions, an emission analyzer has been used to measure CO₂, CO, THC, and NOx emissions. The fuels used in the analyses are 25% (25B) and 100% (100B) of biodiesel blend and diesel. The series of the transient events studied are speed changes from 900 to 1200rpm, 1200 to 1500rpm and 1500 to 1800rpm over a time period of 4 seconds each.