Matlab Analysis

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This report is a documentation of my work as a part of my internship at Nissan Ashok Leyland Technologies Ltd. The work initially involved the study and analysis of Real World Driving Cycles to decide on the parameters to be considered for the development of a half an hour drive duty cycle. This duty cycle is used for testing various vehicle parameters on the Chassis Dynamometer. The duty cycle duration is typically limited to reduce per-vehicle test costs. The various parameters that affect the resulting condensed cycle are considered based on various studies in the preparation of a condensed cycle. The original full cycle and the condensed cycle are then run in “Cruise” software and the results are compared. It was observed that the similarity in the results between the on road cycle and the condensed cycle was proportional to the similarity in the individual parameters for both the cycles. The on road velocity profile is taken as the input for the MATLAB code. Parameters like acceleration and rate of acceleration were found out. Reference values were set for velocity and acceleration to distinguish accelerating, decelerating, idling and cruising intervals. The interval (profile) between two consecutive idling periods was identified as a micro-trip. The condensed cycle was created by combining selected micro trips. Originally in the excel sheet which was developed for the same purpose of creating a condensed cycle similar procedure was followed. But the main disadvantage of doing in Excel is that the selection of micro trips had to be done manually and the percentage error between the original and condensed cycles used to be high. These problems were given consideration. Also additional parameters were included for the selectio... ... middle of paper ... ...on map. So the condensation map was generated for all the individual micro trips. The percentage occurrence of engine in all the regions was calculated. The percentage based condensation maps for the individual micro trips and the full cycle were compared and the condensed cycle was selected on a cumulative basis. The next stage of the project involved the determination of the vehicle fuel economy. For this the SFC map of the vehicle was studied. As the map cannot be directly given as input, it was seen that the fuel consumption at various rpms and torques was given as input in Cruise. For the rest of rpms and torques the value was interpolated from the data we have. So we could find the fuel consumption at each second of the vehicle travel as we had both the engine torque and rpm. The consumption at each point was summed up to get the F.E. for the complete cycle.
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