Yi Qi Zhou

Research on Power Flow Transmitted through Rolling Bearing in the Gear Shaft-Plate Coupled Structure

A dynamical model of a typical composite structure of plate-rolling bearing-gear shaft- rolling bearing-plate was developed, for the analysis of vibration transmission in gearbox systems. Based on the principle of mobility, a modal solution of the vibratory power flow transmitted to the plate through rolling bearings was derived. And by applying the SEA theory, a method was proposed to estimate the coupling loss factor between the plate and the finite shaft supported by rolling bearings. The SEA result was compared with the modal solution, and the properties and influencing factors of vibratory energy transmitted through rolling bearings were analyzed furtherly.

Contribution Study on Cab Noise Source of Construction Machinery

NVH control in construction machinery is multi-disciplinary, comprehensive and complex. In order to achieve noise and vibration control, it is necessary to identify the main noise sources, vibration sources and the corresponding characteristics. To establish a relationship between the machine vibration with the noise sources of an excavator cab, the ICA (independent component analysis) method is employed to separate the multi-channel noise signals into statistically independent components, then utilize time-frequency analysis and correlation analysis to determine the distinct independent noise sources. By introducing energy calculation factor and the mixing matrix A, the contribution corresponding to each noise source can be obtained, which can be utilized to determine the main noise sources. Then by introducing simulation, the correction of the contribution can be verified. By analysis and simulation validation, the effectiveness of our proposed method is demonstrated. Finally, the main noise source is found. Our proposed method can offer an effective guidance to the practical engineering.

Application of Kriging Surrogate Model in Performance Parameters Optimization of Excavator Cab Shock Absorbers

The surrogate model has been extensively applied in engineering optimization design recently. Based on surrogate model, the complicated functional relationships between variables and responses can be precisely described. In this paper, the Kriging surrogate model are adopted to simulate the relationships between the sound pressure level (SPL) peaks at the drivers right ear (DRE) and the performance parameters of excavator cab shock absorbers with the FEM model, followed by the optimization design been accomplished with algorithm NSGA-II. The results indicate that the SPL peaks and the overall SPL can both be decreased through optimizing the performance parameters with Kriging surrogate model.

Acquisition Method of Typical Time Course for Stationary Signal Basing on Frequency Weighting

The cab acoustic response, which could be considered to be random and stationary, determines the riding comfort of the excavator. In order to get the most useful information from the actual cab noise signal, an acquisition method of typical time course for a stationary signal was proposed in this paper. Firstly, a series of de-noising preprocessing was applied on the test signal. Then, the stationarity and ergodicity of that were examined via runs test method. Finally, combining with FFT, IFFT and the frequency weighting, the typical time course was obtained. The results show that the statistical parameters and spectral characteristics of the obtained typical time course are consistent with those of the measured signal, which means that the obtained one could be regarded as a representation of the actual signal for further analyzing more effectively.

Mechanical Parts Recognition with 3D Graphical Modeling

Computer vision based mechanical parts recognition has been received much research attention in recent years. In this paper, we present a new framework to address this problem. The framework utilizes the computer graphic technology to model mechanical parts. Recognition is realized by comparing one query image to the instance images using improved affine transformation based on particle swarm optimization (PSO). Our experiment shows that the proposed framework outperforms the conventional invariant moments based recognition methods in recognition rates.

Vibration and Noise Damping Treatment for an Excavator Cab

Acceleration signals at the mounts of an excavator cab are collected and analyzed, on the basis of which causes of peak values in the sound pressure level (SPL) at the drivers right ear (DRE) are discussed. A damping material layer made up of chlorobutyl rubber is arranged to the cabs panels by simulations according to results of panel acoustical contribution analysis, which indicates a great decline of the SPL peak values.

Research on Relation among Inlet/Outlet Pressure, Pressure Loss and Inlet Velocity of a Complex Resistance Muffler

Simulation models of resistance mufflers with different typical structures were established, through the computational fluid dynamics method, under the conditions of different inlet velocities, by analyzing distribution characteristic of velocity field and pressure field for flows internal the mufflers, a kind of mathematical relation among the inlet velocity, inlet/outlet pressure, and pressure loss was discovered. Through CFD simulation computation and practical measuring tests of above three parameters for practical muffler with complex configurations, the mathematical relation of them was proved to be correct. With the conclusion, while inlet velocity changed, the variable conditions of inlet/outlet pressure and pressure loss for resistance mufflers could be estimated approximately Therefore, the test expense could be saved, and the designing efficiency for mufflers could also be further improved, so it would bring a certain economic benefit,which would be of great significance for energy saving research of mufflers.

Establishing Brand Image through Product Color Design: Exploring Color Design Principles of Construction Machinery Products

Product color design is a powerful tool for establishing brand image. This paper analyzed the development status of construction machinery industry, and on the basis of that presented the necessity of establishing brand image through product color design in the construction machinery industry. Then after analyzing the special environment and people-related elements to be considered when designing construction equipment, and combined with successful brand image construction cases, proposed three principles for the product color design of construction machinery products.

Radiated Noise Source Localization of Hydraulic Excavator Based on Wavelet Packet Analysis

Collect a hydraulic excavators radiated noise ten meters away under set conditions, and also the relevant noises near the excavator. Analyze noise signals with wavelet packet to get the main band of energy distribution. Then calculate the two signals correlation coefficient, which identifies the muffler exhaust noise and inlet noise as the main source for right rear radiated noise.

Vibration Modal Analysis of the Upper Frame of Hydraulic Excavator

As the upper frame is an essential supporting structure of Hydraulic Excavator, dynamic characteristics of the structure are particularly important. The finite element model of the upper frame is established by the finite element analysis software, and then modal analysis is carried out in absolute freeness. The former fifteen modes are adopted to review its inherent frequencies and vibration modes seriously, and the dynamic characteristics of the frame are clear. Analysis result indicates that there are some weak links in the structure, and suggestions of modification are put forward for the further structure improvement.