An Objective Evaluation of Characterisation Matrix for Two Wheeler Powertrain with Control Oriented Mathematical Model 2015-01-1629

The objective of this paper is to estimate characteristics parameters of two wheeler powertrain with simulated vehicle model. The evaluation is applied to define required characteristics for future motor integrated powertrain. The main parameters for the characteristics matrix are Fuel consumption and NOx gas emission. In the 1st phase of work, a mathematical model for the complete powertrain is developed using suitable modelling approach for different sub-modules of the complete system. The objectives of the model are, to simulate dynamic power-flow from the engine to wheel and to simulate NOx gas emission. The powertrain model consists of a carburetted spark ignition (S.I) engine and gear transmission system. The S.I engine model is capable of simulating dynamic torque output of engine as well as the NOx gas emission. The model is experimentally compared with available test data of production ready engine from TVS Motor Company, India. The dynamic effects of change of ignition timing and fueling on torque output and NOx gas emissions are simulated based on this model and discussed on the paper. The paper adapted two types of transmission model, one with Continuous Variable Transmission (CVT) and other one with Fixed Geared Transmission. The mathematical model for the CVT system is developed to capture automatic gear shift actuation and power transfer to the wheel. The model simulates the toque control system of the driven pulley as well as speed control system of the drive pulley. The mathematical model for the fixed gear ratio system with wet clutch system is proposed to simulate the manual gear based powertrain. The above mentioned model demands computationally intensive resources due to presence of higher order dynamics, mathematical discontinuity and non-linear functions. So this model is not suitable for control design application. In 2nd phase of work, the model is converted to lower complexity control oriented model by using feed-forward approach. The control oriented model is capable of simulating the wheel torque fluctuation and NOx gas emission variation with the change of engine operating point. The main parameters for the characteristic matrix can be evaluated by simulating the above mentioned control oriented model in a drive cycle. In the 3rd phase of work, the control oriented vehicle model is coupled with a Driver model for drive cycle simulation. The main characteristic parameters for both the powertrain configurations are captured from the drive cycle simulation. The results of the simulation are categorized and discussed in the final phase of work. This best found values of two parameters for both the configurations are utilized to build the characteristics matrix.