The design analyze of new hybrid drive concept

This paper presents the design method of hybrid drive system for the minibus with some limited conditions. The approach of design hybrid drive system is based on the dynamic modeling and simulation of the hybrid minibus with planetary gear system. The main target of the design is to obtain the optimal design with the proper hybrid drive configuration and control for a given set of design constraints. In oder to meet the design target, it＇s necessary to adjust some parameters such as mechanical ratios and parameters of battery pack as well as control by simulation. During simulation the transient operating process can be studied in details with the dynamic model in Matlab/Simulink. The control strategy can be optimized by running the simulation and monitoring the operation of each components： the operating area of internal combustion engine （ICE）, fuel consumption （energy consumption）, the power distribution, the torque and rotary speed of ICE and motor, the operating efficiency of motor, the aheration of battery state of charge （SOC）, current and voltage.

The Non-Smooth Problem of Wheel Motion

Planar motion of a non-deformable wheel under the action of non-ideal unilateral constraints is considered. The mathematical description of this phenomenon has a form of a non-smooth initial value problem. The non-smoothness of this problem means that its solution is determined by an absolutely continuous function having a discontinuous first derivative. For this reason, a collision problem describing abrupt changes of velocity has been formulated next to the equations of motion specifying the acceleration. The non-idealness of constraints means that the constraint reaction force includes also a component resulting from the friction between the wheel and the constraints. Differential equations specifying acceleration of the wheel making contact with the constraints and algebraic equations for determining the changes in the wheel’s velocity at the moment of collision have been formulated in the paper. The principal task in these formulations is to determine the reaction forces of the considered constraints. This task is specified by the relationships between acceleration and the constraint reaction force components. In the description of the collision, these relations refer to the post-collision velocities and reaction force impulses. For determining an approximate solution of the formulated wheel motion problem, an original numerical method and a computer program for wheel motion simulation have been developed. Selected results illustrating the changes in displacements and velocity have been presented.

Zero steady-states electrical energy consumption clutch system

A new clutch configuration with dual diaphragm spring is proposed. It is proper designed for electric and hybrid powertrain system. With this design, the clutch engagement is controlled by current in electrornagnet coil. For special characteristic of dual diaphragm spring, the clutch does not consume energy in steady state after engaging or disengaging. To validate the feasibility of this design, author builds the mathematical model and imports it into MATLAB Simulink. The simulation shows the behavior of clutch in different control strategies.

A Fourier spectrum-based strain energy damage detection method for beam-like structures in noisy conditions

In this paper,the Fourier spectrum-based strain energy damage detection method for beam-like structures is proposed based on the discrete Fourier transform.The classical strain energy damage detection method localizes damage by the comparison of the strain energy between the intact and inspected structures.The evaluation of the 2nd-order derivative term in the strain energy plays a crucial part in the comparison.The classical methods are mostly based on a numerical derivative estimation for this term.The numerical derivative,however,introduces additional disturbances into damage indications.To address this problem,a discrete Fourier transform-based strain energy is proposed with the emphasis of enhancing the performance in noisy condition.The validations conducted on the simulated and experimental data show that the developed method is effective enough for composite beam damage detection in noisy environments.

Damage localization for beams based on the wavelet correlation operator

The continuous wavelet transform(CWT) is one of the crucial damage identification tools in the vibration-based damage assessment. Because of the vanishing moment property, the CWT method is capable of featuring damage singularity in the higher scales, and separating the global trends and noise progressively. In the classical investigations about this issue, the localization property of the CWT is usually deemed as the most critical point. The abundant information provided by the scale-domain information and the corresponding effectiveness are, however, neglected to some extent. Ultimately, this neglect restricts the sufficient application of the CWT method in damage localization, especially in noisy conditions. In order to address this problem,the wavelet correlation operator is introduced into the CWT damage detection method as a post-processing. By means of the correlations among different scales, the proposed operator suppresses noise, cancels global trends, and intensifies the damage features for various mode shapes. The proposed method is demonstrated numerically with emphasis on characterizing damage in noisy environments, where the wavelet scale Teager-Kaiser energy operator is taken as the benchmark method for comparison.Experimental validations are conducted based on the benchmark data from composite beam specimens measured by a scanning laser vibrometer. Numerical and experimental validations/comparisons present that the introduction of wavelet correlation operator is effective for damage localization in noisy conditions.