An intelligent fault diagnosis system for newly assembled transmission

•We present a fault diagnosis expert system for newly assembled auto transmission.•Synchronous data acquisition algorithm of the vibration signal and the speed signal.•Improved FFT algorithm which is used for spectral transformation after a lot of tests.•Knowledge representation and knowledge renew algorithm for transmission.•Improved genetic algorithm for feature selection and fault classification with BP network.

Newly assembled automobile transmission has its particular failure characteristic, strict quality testing working procedure on the assembly line is important for quality of automobile transmission. In this paper, we introduce a new automatic fault detection method for automobile transmission. A fault diagnosis expert system for newly assembled transmission is presented, related method of knowledge representation, feature extraction and fault classification is given. Order spectrum analysis method is used to analyze vibratory signal of automobile transmission. After initial feature vectors set are obtained, improved genetic search strategy is used to select fault features, so as to reduce the dimension of feature vector set. Selected feature vector sets are inputted into the BP neural network for fault identification and classification of the newly assembled automobile transmission. A large number of data are collected from industrial site and analyzed, proposed algorithm is verified to be effective and exact.