Papers by Author: Bing Yan

Abstract: In this paper, the three dimensional geometrical analysis is depicted with the interacting relations among cutting edge, undeformed chip and shear zone along cutting direction, and a general geometrical model of five-axis machining curve surface in ball-end milling is presented. A general force model is derived, and the three dimensional cutting forces are predicted. The influences of different angle of the centerline of the cutter to the cutting forces are considered. The three dimensional cutting forces are applied to construct and analysis the structural vibratory model of the system.

Abstract: Considering the low productivity of fixed molded honeycomb mold, an efficient turning molded honeycomb mold is developed. Using TRIZ theory, a technical analysis of fixed molded honeycomb mold is conducted. Through the TRIZ innovation principles of the Spheroidality, combined with the characteristics of the mold, innovative design of the rotary molded honeycomb mold has been made. According on the Pro/MECHANICA analysis platform, by the finite element analysis method, the actual molded honeycomb mold forces, boundary conditions and imposed load are being researched in the view of the molded honeycomb mold for the actual operating conditions. The sensitivity analysis of mold parameters is conducted so as to optimize the structure parameters of mold. Shown by the practical application, the rotary molded mold can improve the productivity significantly.

Abstract: The machining characteristics of hardened still for mould and die greatly affect the accuracy and productivity in industry. The physical modeling and simulation of ball end milling is investigated in this paper. The influence of cutting speed to the cutting mechanism in high speed cutting is taken into account and the momentum force of chip is introduced into the model. By analyzing the shape of the chips the relationship between the cutting speed and shear angle is obtained. The model has been tested on 718HH, with appropriate Seco tools. The validation shows that the adjustment between the model and the real force is adequate, both in shape and magnitude.

Abstract: This paper studies the problem of motion planning of wheeled mobile robot (WMR), which is driven by double wheels separately. It mainly accomplish the motion planning of WMR by taking center of one of double wheels as a base point, and also carry out this problem by traditional method, which takes the midpoint of interval between two wheels as a base point. Besides, these two motion planning methods are compared. Experimental results show that the first motion planning method is simply controlled, saves much computer time and it establishes the foundation to solve the problem of real time control to WMR.

Abstract: In order to improve the machining accuracy of the precision surface grinding machine, a 3-DOF micropositioning table is used as an auxiliary table to form the dual infeed system with nanometer level positioning accuracy. This paper mainly deals with the static characteristics of the micropositioning table. The direct and inverse kinematic models are obtained under different orientation descriptions, and the inherent relationship between different orientation descriptions is investigated. By use of Eular angle description, the reachable orientation space of the micro-positioning table is obtained. The theoretical static stiffness on the top surface of the table is also given, and the experimental tests are carried out to verify the established models.

Abstract: In order to compensate the force induced deformation of the precision grinding, a piezoelectrically driven micropositioning table is developed to actuate the workpiece for error compensation. To better understand the performance of the micropositioning table, the deformation patterns and stiffness distribution of the micropositioning table under normal grinding force are investigated by computational finite element analysis method. It is noted that the moving part of the micropositioning table can be considered as rigid body and the maximum static stiffness is located at the center of the top surface. The experimental tests are carried out to verify the analysis.

Abstract: In order to implement dynamic compensation for the wheel vibration of surface grinding machine, a micropositioning table with high stiffness and response frequency is designed. The micropositioning table is driven by three piezoelectric actuators with stiffness of 400 N/μm. Three capacitive sensors are utilized to form feedback control and flexure hinges are used to guide the moving part and preload for the piezoelectric actuators. The kinetics of the micropositioning table has been analyzed to understand the relationship of the control voltage and the posture of the moving part. Due to the coupling characteristic of the system, the decoupling control method is introduced to improve the performance of the table. Experimental tests are carried out to investigate the performance of the micropositioning table.

Abstract: In order to eliminate the non-linearity of a grinding auxiliary workpiece table, a hybrid fuzzy PID controller has been developed. The two-dimensional fuzzy control with self-tuning factor is utilized to improve the performance. The Max-Min inference mechanism and COG defuzzification method are used to obtain the crisp output of the fuzzy controller. To eliminate the oscillation at balance position, the conventional PID controller is used in the small range of the error and the switch between two controllers can automatically realize according the preset value. Simulation and experimental testing have been carried out to validate the performance of the hybrid fuzzy PID controller.