Papers by Author: X.J. Shi

Abstract: As an important component of automobile, the quality control and tracility of airbag’s manufacturing process is very important. In this situation, an assembly line is put forward which is made up of computer, barcode scanner, electric nut runner and specialized electric testing instrument. System uses the Client/Server framework , bar code technology and SQL database to save or find the assembly data and the information of the operators. Electric nut runner is used to control the torque value of the nuts. Specialized electric testing instrument is used to test the electric parameters of the airbag. By the practical application in the assembly line, there are many advantages of this system such as good human-machine interface, fast response, and so on. This system can be used for many products, and it is an flexible assemble line with procedures rectification, quality control and product tracing.

Abstract: The mechanical equipments driven by induction motor are widely used in manufacturing. Aiming at this type of equipment, some holes are advisedly drilled on the bars to simulate the broken bar faults of the motor, and with on-off loads changes of output circuit of the load generator, forced torsional vibration of rotor was generated. Using the above simulation test ways, the typical faults of motor and its driven equipment are tested and analyzed. In addition, an signal analysis method using Hilbert conversion envelope spectrum and real modulation zoom envelope spectrum is proposed, this method can effectively extract the faults information of stator current, reject the useless power frequency. The experimental results indicate that: this method can identify not only the faults of the motor itself, but also municipal fault types of the motor’s driven equipment. Especially, through the contrastive experiments on the unbalance and the torsional vibration of the rotor, the conclusion is made that the method is more sensitive to torsional vibration detection. Also, it develops a new direction for the application and the research of sensorless detection and diagnosis method.