Papers by Author: Hong Ya Fu

Abstract: Automatic tape laying is a widely-used fabricating process for fiber-reinforced composite materials in aerospace and aviation industry. To fulfill the tape laying process, it is necessary to cut the prepreg tape into designated shape accurately and promptly. In this paper, a scheme of ultrasonic cutting bench is put forward to investigate the parameters of ultrasonic cutting process. The functional requirements are analyzed and the key components of ultrasonic cutting bench, such as transverse feed mechanism of cutter, revolving gear of cutter, and mechanism for precision positioning of cutting depth, are presented in detail, which lays a solid foundation for future experimental research.

Abstract: A review of methods used for fault recognition of the rolling elements in gearbox, namely gear and bearing, is presented in this paper. The procedure of the fault recognition can be classified into three phases, which are data acquisition, data processing or important features extraction, and the fault mode detection. Many different methods have been developed in dealing with each phase, so that the arrangement of the entire process has different strategies. This paper summarizes some general used and recently popular developed methods of each phase, and makes comparison between them. This work also aims at giving a perspective in such area in the future, based on the known researches.

Abstract: Form grinding is one of the most efficient processes for finish machining of gear wheels. This paper investigates the method of system development for wheel modification of involute cylindrical gear based on SINUMERIK 840D system and its OEM development package. The control software developed for form grinding is applied to dress form grinding wheel by using the numerical control dresser, and normal projection is adopted as the method to calculate the sectional shape of grinding wheel. The friendly interface of control software, edited by Visual Basic was developed to meet needs of users. Finally, personalized interface and processing methods are integrated and embedded in Siemens CNC system through Dynamic Link Library to implement parameterized automatic processing, which is more efficient in programming and machining.

Abstract: The magnetic flywheel is widely used in energy storage and spacecraft, and it needs to reduce the system’s power consumption effectively when designing the controller. Always, the magnetic bearing system’s performance depends on the tracking performance of the desired force signal. In order to balance the two goals between reducing magnetic system’s power consumption and guaranteeing its performance, a current power allocation way was proposed, and a static current optimization was given based on the way. According to the simulation and experimental results, this method can reduce the magnetic bearing system’s power consumption significantly and keep the tracking performance of force signal well on the same time.

Abstract: Based on the principle of axial active magnetic bearing rotor-system with single degree of freedom, magnetic rotor-system vibration mode was described. A 3D finite element model of active magnetic bearing rotor-system was established by ANSYS11. Initial six order natural frequencies and vibration mode were calculated by the module of modal analysis of ANSYS11, and compared with the results of system identification. Analysis shows that there was a certain difference between the results, but the difference was small. The analysis result indicates that it is an effective method to apply FEA in the design of the active magnetic bearing. It provided the foundation for structure optimal design of the system and theoretical basis for flexible system design.

Abstract: In order to overcome the system nonlinear instability and uncertainty inherent in magnetic bearing systems, two PID neural network controllers (BP-based and GA-based) are designed and trained to emulate the operation of a complete system. Through the theoretical deduction and simulation results, the principles for the parameters choice of two neural network controllers are given. The feasibility of using the neural network to control nonlinear magnetic bearing systems with un-known dynamics is demonstrated. The robust performance and reinforcement learning capability in controlling magnetic bearing systems are compared between two PID neural network controllers.

Abstract: The numerical simulation of hot-stamping process was carried out for UHSS square-cup parts, and the influence of dies temperature on the hot-stamping process was anlysised. Besides, through the microstructure analysis and mechanical properties testing of the formed parts, effects of dies temperature on microstructures and mechanical properties of hot-stamping square-cup parts were obtained. The experiment and simulation results showed that the mechanical properties of the UHSS are strongly dependent on the temperature, so the dies temperature is one of the most important parameters that have to be taken into account in designing the hot-forming dies and the hot-forming process.

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.

Abstract: The numerical control (NC) program files need re-generating if there is any tool dimension change or tool wear for multi-axis machining. If the tool is replaced to adapt this change there will be increased cost. To solute this problem, 3D cutter radius compensation method for 5-axis computer numerical control (CNC) machining is deeply researched. Taking five axes linkage machine tools of X, Y, Z, B, C form with rotary tables B and C as an example, coordinate transformation matrix (CTM) and the cutter compensation vector for 3D cutter radius compensation are derived. The discrimination methods for path joint pattern (PJP) are given. A controller with 3D cutter radius compensation function for 5-axis linkage CNC machine tools is developed based on this method. The controller is allocated to a 5-axis milling machine tool and experiments are done. The proposed algorithm is demonstrated using a practical example.

Abstract: A micro-drive device was developed to drive reflective lens frame in Inertial Confinement Fusion. The transmission consists of ball screw, flexible hinge and electrical control unit. Two different flexible hinges named straight round and cylinder interlaced flexible hinge were used in device. The communication between IPC and PLC is founded by MSComm, which realizes the distributing system. Tested on TM5 reflective lens frame of SG- III prototype facility, the precision achieved ±0.3μm/step, which meets the design target.