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Engine calibration on the powertrain test bed with transient mode is proposed with dynamic powertrain test bed having low inertia dynamometer. Automated ECU (Engine Control Unit) calibration system is completed with the combination of experimental design software, powertrain test bed, evaluation tools and their electrical interfaces. The process is composed up of the system interface definition, test design using DoE skill, test proceedings by step sequence of connecting systems, measured data collecting, mathematical model and optimization result extraction at the end. All the processes are automated by interfaces between the systems. Acceleration surge is minimized by proposed process by optimizing combustion control labels and tip in driveability is maximized by manipulating torque filter labels of EMS (Engine Management System) logic. Their detailed steps from the problem definition to the verification test results of improved design with vehicle test are presented.

This paper presents a series of experimental and analytical works to improve driving surge in a vehicle with CVVT (Continuous Variable Valve Timing) engine. To fully understand the surge mechanism, comprehensive vehicle tests were performed in relations to engine pressure variations, rotational dynamics of driveline, and rigid body dynamics of powertrain. Base on such experimental results, a simple yet reliable model was developed and simulated to optimize driveline. This study found that parameters, such as characteristics of the clutch in a torque converter, roll mode of powertrain, and timing of CVVT, were shown to have noticeable influence on performance of driving surge. A significant improvement in surge vibration was possible by optimizing each of these parameters both through simulations and experiments.

Gear rattle is generated basically due to the impacts of unloaded gear pairs in transmission. The rattle noise level is determined by two main factors, excitation level at transmission input shaft and rattle sensitivity of the transmission at that excitation level. In this work, (1) the transmission rattle sensitivity was measured and investigated (2) torsional vibration model of driveline system was developed to estimate the speed fluctuation at the transmission input shaft and to find some rattle improvement potential by tuning driveline components so that the speed fluctuation be minimized.

Driveline clunk is perceived as disturbing metallic noise due to severe impact at driveline components such as gear pairs when the engine torque is suddenly applied and transmitted to the driveline system. In this work, experimental method detecting the most contributive gear pair to the clunk generation was investigated and applied to mini van vehicle of front-engine and rear-wheel-drive. Another experimental method, TPA (Transfer Path Analysis), was employed to identify transfer path of the clunk. And then, driveline clunk model was developed using commercial multi-body-dynamics program, ADAMS, in order to further investigate the critical clunk mechanism and potential clunk reduction solutions by performing parameter study.