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机床工况识别与人机效能评估[范文]

时间:2017-12-02 12:48:18 编辑:知网查重入口 www.cnkiid.cn

 

摘  要

随着科技的迅猛发展,机械设备在各行各业得到广泛使用,如何准确监测设备当前的健康状态和控制性能,如何评价工人的操作水平,以及计算设备生产成本对于管理者科学管理企业尤为重要。本文以普通车床为例,运用三种方法对车床振动信号进行分析处理,实现状态识别,统计出车床各个工况的时间,并根据车床实时振动信号进行一系列分析,实现对操作人员和车床的相应评估。

本文信号采集对象是某种型号车床,在本文进行研究内容包括:

(1) 基于神经网络与主元分析方法对听觉感知特征集进行优化。车床每种工况信号先经过ZCPA听觉模型处理得到听觉谱,然后对听觉谱提取听觉感知特征。通过遗传算法优化神经网络中神经元连接权值和阈值,把听觉感知特征集作为神经网络结构的输入,经过非线性映射,网络输出的新特征集经过主元分析计算,使不同工况的新特征集在第一主元方向投影数据实现可分。

(2) 运用遗传算法对ZCPA听觉模型进行优化,提高听觉模型对各种状态信号的适应性,使车床不同状态振动信号生成的听觉谱之间差异性更明显。同时通过改进相关性计算公式,能够在形状和幅值两方面识别待识别信号,提高识别率。

(3) 基于听觉显著模型和信息熵对车床工作过程信号进行状态识别。振动信号经过听觉显著模型处理得到全局显著图,根据全局显著图的波动趋势找到振动信号的冲击点,然后根据冲击点前后信号的信息熵特征对冲击点进行判断,看其是否为相邻状态的切换点。通过提取切换点实现状态识别。

(4) 根据振动信号的信息熵判断出设备的当前健康状态;根据振动信号显著图能量参数、波动特性、烦恼度等参数判断工人操作水平;根据车床各状态的时间计算生产成本。

 

 

关键词:ZCPA听觉模型;神经网络;遗传算法;主元分析;信息熵;听觉显著模型

 

 

Research on Machine Tool Condition Recognition and

Man-machine Effectiveness Evaluation

Abstract

With the rapid development of science and technology, mechanical equipments are widely used in all walks of life, how to accurately monitor the current health status and the    control performance of equipment, how to evaluate the level of operation of workers, and calculating the cost of production are particularly important for managers to manage the industry scientifically. In this paper,take an ordinary lathe as an example, three methods are used to analyze and process the vibration signal of the lathe to realize the state identification and calculate the time of each working condition of the lathe. According to the real-time vibration signal of the lathe, we can achieve a series of analysis about the operators and the lathe.

In this paper, the signal acquisition object is a certain type of lathe, the research contents include:

(1) To optimize the auditory perception feature set of signals under different operating conditions based on neural network and principal component analysis. Signals of each working condition is processed by the ZCPA auditory model to obtain the auditory spectrum, and then the auditory perception feature is extracted from the auditory spectrum. The weights and thresholds of neural connections in neural networks are optimized by the genetic algorithm, the auditory perception feature set is used as input of the neural network. Through nonlinear mapping of neural networks, a new feature set is obtained. After the new feature set is analyzed by principal component analysis, the projection data of the new feature set in the first principal component direction can be classified.

(2) Using the genetic algorithm to optimize the ZCPA auditory model, the adaptability of the auditory model to various state signals is improved, and the difference between the auditory spectrum generated by each state data is increased. At the same time, through the improvement of the correlation formula, the signal can be recognized in two aspects of shape and amplitude, and the recognition rate is improved.

(3) Status recognition of lathe working process signals based on auditory significant model and information entropy. The vibration signal is processed by the auditory significant model to obtain the global significant graph. According to the fluctuation trend of the global significant graph the impact point of the vibration signal is found. Then, according to the information entropy characteristic of the signal before and after the impact point, the impact point is judged whether it is the switching point of the adjacent state. State recognition is achieved by extracting switching points.

(4) According to the information entropy of the vibration signal, the current health status of the equipment can be determined. According to the calculation of vibration signal significant map energy parameters, fluctuation characteristics, annoyance and other parameters, the workers' level of operation can be judged. Calculating the cost of production according to the time of each state of the lathe.

 

 

Key words: ZCPA auditory model; neural network; genetic algorithm; principal component analysis; information entropy; auditory significant model

 

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