Papers by Author: Xiang Zhang

Abstract: This paper proposes a hydraulic measurement model for measuring the Laval nozzle throat diameter size. Based on measurement principle of liquid pressure – flowrate, we can get the size of Laval nozzle throat diameter by measuring the fluid flowrate through hydraulic measurement model at the fixed pressure. With good viscosity-temperature performance, low temperature performance and oxidation stability, UCBO aviation hydraulic oil is selected as the measuring medium. In the hydraulic measurement model, the diameter of the mandrel which can be regarded as gauge will directly affect the sensitivity of diameter measurement. Therefore we need to optimize the design of the mandrel of the hydraulic model.

Abstract: The disturbance torque which is caused by the interference of the motor position has observably impact on accuracy of the loading system. According to unstable loading channel and disturbance torque, this paper use a complex control algorithm of differential forward PID control and feed-forward compensation. At the end of this paper, the simulation analysis results show that the feed-forward compensation can observably eliminate the influence of the disturbance torque, and improve the accuracy of the loading system.

Abstract: In this paper, a mathematical model of the loading system is established. The characteristics of the loading channel and disturbance channel are analyzed through this mathematical model. Analysis results show that the loading channel is unstable and disturbance torque leading the input command. It directly impact on the output torque, serious affect the systems loading precision. Characteristics of the loading system are analyzed, and the results show that stiffnesss effect on the loading system is twofold, should be considered at the same time. Reduce the system's moment of inertia is good for the characteristics of the loading system.

Abstract: This paper describes a distributed control system, which is based on PIC microcomputers. The hardware of this system included industrial personal computer, RS232-RS485 converter, control circuit, motor driver and so on. The PIC microcomputers on control circuits are used as basic control chips. The software of system is developed by Visual C++, communicates through the RS485 bus. The human-machine interface is developed, which is intuitive and friendly. Test result shows that the control system is effective and reliable.

Abstract: This paper describes machining trajectory generation and simulation of miniature integral impeller. Taking into account the closed and miniature of integral impeller, and low stiffness of the micro-milling tool, in order to avoid interference in the processing, through reasonably division of the impeller blade surface, generate the miniature integral impeller machining trajectory. Then impeller machining NC code is generated, and is simulated in Vericut software. Simulation result shows that the machining programs generated in this paper are effective, and the simulation machined workpiece surface is relatively smooth.

Abstract: Currently machine tools and strategies researched in micro-milling field universally cannot be applied to 3D meso-scale parts machining directly, so great importance should be attached to the research on 5-axis machine tools and the suitable strategies for 3D meso-scale machining. This paper introduced a self-made 5-axis machine tool and several micro-milling strategies which were applicable to 3D meso-scale parts machining. Using these strategies, a mini impeller was successfully machined on the 5-axis machine tool developed independently. The experiment result showed the machine tool and the strategies were suitable for machining meso-scale 3D parts.