Multi-objective optimisation of centrifugal pendulum vibration absorber performance during engine startup

Abstract

A centrifugal pendulum vibration absorber generates a reverse torque through the periodic reciprocating motion of a pendulum, offsetting specific orders of torsional vibration in a power transmission system. In practical applications, it exhibits strong nonlinear characteristics, resulting in complex and variable system responses that are difficult to predict. In particular, the centrifugal pendulum vibration absorber in an automotive engine operates in a vertical plane, and the pendulum response during system startup is significantly affected by the initial pendulum position. Under certain unfavourable conditions, irregular collision between the pendulum and its position-limiting mechanism aggravates the fluctuation of the power source output torque, resulting in noise, vibration, and harshness problems, and shortening the life of the system. To solve the above problems, in this study, a multibody dynamics model including an engine, dual-mass flywheel, centrifugal pendulum vibration absorber, and drivetrain was established, and the response of the system during the engine start-to-idle condition was numerically simulated. A multi-objective optimisation strategy was applied to enhance the system startup performance, reduce pendulum collision with its position limiting mechanism, and reduce the system torsional vibration by adjusting the controllable parameters of the engine electronic control unit and starting status of the centrifugal pendulum vibration absorber. The results indicated significant improvements of the system stability and durability. In conclusion, the study findings can provide important guidance for the design of high-performance and long-life vehicle powertrains.