Research on Fault Diagnosis of Air Conditioner Based on Deep Learning

Abstract

The essence of intelligent fault diagnosis is to classify the feature of faults by machine learning. It is difficult and key to extract fault characteristics of signals efficiently. The general feature extraction methods include time frequency domain feature extraction, Empirical Mode Decomposition (EMD), Wavelet Transform and Variational Mode Decomposition (VMD). However, these methods require a certain prior experience and require reasonable analysis and processing of the signals. In this paper, in order to effectively extract the fault characteristics of the  air conditioner's vibration signal, the stacked automatic encoder (SAE) is used to extract the feature of  air conditioner’s vibration signal, and the Softmax function is used to identify the  air conditioner's working condition. The SAE performs unsupervised learning on the signal, and Softmax function performs supervised learning on the signal. The number of hidden layers and the number of hidden layer's nodes  are determined through experiments. The effects of learning rate, learning rate decay, regularization, dropout, and batch size on the correct rate of the model in supervised learning and unsupervised learning are analyzed. Thereby realizing the fault diagnosis of the air conditioner. The recognition correct rate of deep learning model reached 99.92\%. The deep learning fault diagnosis method proposed in this paper is compared with EMD and SVM, VMD and SVM two kind of fault diagnosis methods.