越野汽车液力变矩器和机械自动变速器换挡规律研究

根据越野汽车行驶特点,按照发动机与液力变矩器合理匹配的原则,确定了共同工作特性和最佳动力换挡点。制定的液力变短器和机械自动变速器的综合换挡规律,既可满足低挡位越野性能和机动性能的要求,又可在良好路面、高挡位行驶时满足燃油经济性的要求。     

混合动力电动汽车动力总成换挡过程协调控制仿真

介绍了装有AMT的混合动力电动汽车(HEV)换挡过程协调控制逻辑。在Matlab/Simulink和Matlab/Stateflow平台上建立了动力总成模型,并对分离离合器和不分离离合器的两种不同换挡控制策略下的换挡过程协调控制进行了仿真计算。仿真结果表明,所建立的仿真模型能够对HEV的换挡过程协调控制进行模拟,所采用的协调控制逻辑能够使换挡顺利完成。     

Stochastic wave spectra estimation (SWSE) based on response surface methodology considering uncertainty in transfer functions of a ship

In this paper, a new wave spectra estimation method is proposed in which the frequency domain wave estimation method (FDWE) is extended into a probabilistic analytical framework in order to estimate the encountered sea states involving uncertainty in transfer functions of a ship. The proposed method, named the Stochastic Wave Spectra Estimation (SWSE), makes use of an Hermite polynomial chaos expansion (PCE) to represent the uncertainty in the transfer functions and the response surfaces. The method involves a mathematical formulation where an extension of the deterministic FDWE concept to the space of random variables is made. The proposed method can accurately and easily estimate the encountered wave spectra based on ship response measurements accounting for uncertainty in the transfer functions. In this paper, numerical and experimental investigations of the proposed SWSE are made, where the uncertainties in the transfer functions of heave and pitch motions of a containership are taken into account. The validity of the SWSE is demonstrated by comparison to results of uncertainty analyses through the Monte-Carlo simulations (MCS).