工程机械驾驶室噪声源识别

发布时间：2018-07-31 13:04

【摘要】：噪声是工程机械质量评价中是一个重要因素,驾驶室内噪声水平不仅关系到整车的噪声性能,更是对工程机械整体性能提供一个重要指导,由于结构件的振动关系到驾驶室员的舒适性,正确识别引起驾驶室噪声的振源对驾驶室员操作的安全健康有着重要影响,故对噪声源识别在对驾驶室噪声控制方面有重要意义。本文是在校企合作项目“某型号推土机驾驶室内噪声整改”的基础上进行的,对该类型的工程机械司机耳旁噪声成因及特性进行分析论述,明确空气声和固体声对耳旁噪声的影响,有针对性的提出减振降噪措施降低驾驶室司机耳旁噪声。采用小波包分析及支持向量机模式识别方法对驾驶室噪声源研究。分析驾驶室外辐射噪声通过孔缝泄露进入驾驶室内对耳旁噪声贡献所占的噪声比重,采用小波包分解算法,对噪声信号进行三层小波包分解,进行信号特征提取,计算机外辐射声与耳旁噪声的相关系数,进而计算辐射声对耳旁噪声的贡献量。对驾驶室内结构件及少数车身结构件振动对耳旁噪声的影响分析时,依据小波包分析提取结构件的归一化能量作为特征,采用支持向量机的模式识别方法,在所分析的每两个结构件之间构造子分类器,通过模式识别来判断耳旁噪声与某处结构件特征更为接近,进而识别对耳旁噪声贡献大的结构件,同时采用相关系数计算来验证提出该方法的有效性。考虑到驾驶室减振衰减传递进驾驶室的振动能量,对驾驶室四点减振结构建立相关系数计算模型,查看对减振耳旁噪声贡献度。依据分析结论对机外辐射声传递进驾驶室的噪声分量提出相应的隔声及驾驶室密封措施；对影响驾驶室内及驾驶室周边的振动结构件提出改善结构的局部设计进行改善整车性能；对驾驶室减振结构,根据改善减振器件刚度来提高驾驶室的减振性能,依据分析结论在试验中验证典型结构件对耳旁噪声的影响。
[Abstract]:Noise is an important factor in the quality evaluation of construction machinery. The noise level in the cab not only relates to the noise performance of the whole vehicle, but also provides an important guidance for the overall performance of the construction machinery. Because the vibration of the structural parts is related to the comfort of the cab staff, the correct identification of the vibration source which causes the cab noise has an important effect on the safety and health of the cab operator, so it is of great significance to identify the noise source in the cab noise control. On the basis of the project "noise rectification in the cab of a certain type of bulldozer", this paper analyzes and discusses the causes and characteristics of the noise around the ear of the driver of this type of construction machinery. The influence of air sound and solid sound on the noise around the ear is clarified, and the vibration and noise reduction measures are put forward to reduce the noise around the ear of the driver in the cab. Wavelet packet analysis and support vector machine (SVM) pattern recognition are used to study cab noise sources. This paper analyzes the proportion of noise caused by the leakage of radiation noise from outside the cab to the ear noise in the cab through the hole slot. The wavelet packet decomposition algorithm is used to decompose the noise signal with three layers of wavelet packet to extract the characteristics of the signal. The correlation coefficient between the external radiated sound and the paraural noise is calculated, and the contribution of the radiated sound to the paraural noise is calculated. When analyzing the effect of vibration on the noise around the ear of the structural parts in the cab and a few body parts, the normalized energy of the structure is extracted by wavelet packet analysis, and the pattern recognition method based on support vector machine is adopted. A sub-classifier is constructed between each of the two structures analyzed. By pattern recognition, it is determined that the noise near the ear is closer to the feature of a certain structure, and then the structure that contributes a lot to the noise around the ear is identified. At the same time, correlation coefficient calculation is used to verify the effectiveness of the proposed method. Considering the vibration energy transmitted from the cab to the cab, the correlation coefficient calculation model is established for the four-point vibration absorption structure of the cab, and the contribution to the noise around the ear is checked. According to the conclusion of the analysis, the corresponding sound insulation and cab sealing measures are put forward for the noise components transmitted into the cab by the external radiation sound. To improve the local design of the structure for the vibration structure affecting the cab and the surrounding of the cab, to improve the performance of the cab, to improve the vibration absorption performance of the cab according to improving the stiffness of the vibration absorber, and to improve the vibration absorption performance of the cab by improving the stiffness of the vibration absorber, the local design of the structure is improved. According to the conclusion of the analysis, the effect of typical structure on the noise around the ear was verified in the experiment.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU602;TB53

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