Advanced Materials Research Vols. 605-607

Abstract: A fuzzy adaptive terminal sliding mode control scheme for the attitude of flapping wing micro aerial vehicle is proposed in this paper. Based on the feedback linearization technique, a terminal sliding mode controller is designed. The singularity of the controller can be solved through switching between terminal sliding mode surface and linear sliding mode surface. To reduce the chattering in the control input, a fuzzy controller is designed to adaptively adjust the gain of the terminal sliding mode controller according to the normal of the terminal sliding mode surface. The stability of the control scheme is verified by using Lyapunov theory. Simulation results show that the proposed control scheme is effective.

Abstract: Electromechanical actuator (EMA) behaves as the constant power load for its closed-loop structure. EMI filters are needed to eliminate the interferance for the network. This paper proposed a novel compensation method for the 270V DC power distribution with EMA to solve the stability problem as well as to reduce the disturbance. The main emphasis is placed on the design of compensator for achieving excellent dynamics characteristics of the EMA system. Simulations for the EMA system with compensator were done to verify the performance. The results indicates that extra compensator with appropriate parameters can improve the power quality.

Abstract: The dual characteristic of magnetorheological rheology and phase transitions is studied and its rheological principle is also described. By using the ANSYS finite element method, a simulation analysis of the torque transmission model is conducted. By selecting the magnetorheological fluid SG-MRF2035, a magneto-rheological torque servo device prototype (Gap of 1.5mm) is developed. And a performance testing platform is built for the torque output characteristics of prototype. The test results show that the device could provide supple output torque and the torque is continuously adjustable. This paper provides a new way for the wide application of magnetorheological fluids.

Abstract: Under different throttle type, the bearing lateral force is calculated with the heeling angle changed by using the finite volume method. Also, cavity diameter and depth are selected, which can get influence on bearing lateral force in the same heeling angle. By attributing the error between experiment results and compensational ones to measurement error and instrument error itself, the results are verificated.

Abstract: Due to the structural characteristic, the dynamic performance of the high speed spindle is influenced by multi-coupled parameters. Conventional control method can’t attain the satisfied control result. So the view of internal model decoupling control of high speed motorized spindle is put forward, which can improve the performance of vector control system. In this paper, mathematical model based on internal model control of high speed spindle is set up. And voltage and current of stator are decoupled. At last, through simulation, it is proved that the method can improve the control effect and has better robustness, dynamic characteristic. Therefore, internal model decoupling control of high speed spindle is feasible and effective.

Abstract: Tobacco harvesters are used in large-scale reclamation area. The demand for automatic navigation is urgent because of long time and intensive labor. According to the specificity of tobacco fields’ environment, the conventional path recognition method had been improved, which was taking 2G-R-B processing, threshold processing in turn and adopting dilation algorithm in image morphology instead of median blur algorithm. At last, modified Hough transform was used to extract navigation line. Processing results show that the algorithms which can be underlain in vision navigation research of tobacco machinery can meet the demand of vision navigation in tobacco fields and obtain the target navigation path rapidly and reliably.

Abstract: In this paper, a method of NC process information extraction and import to template file based on Process Recording Files and database was proposed, which provides an effective way for NC process information sharing and reuse, and made positive effect on current situation in CNC manufacturers, such as: type of product is relative stable, process of CAM programming has lots of duplication, process parameters are dependent on programmers, the processing quality is instable and so on. The Process Recording Files are from mainstream heterogeneous CAM softwares, such as: PowerMILL, UG/CAM, which used to record CAM programming process, macro files from PowerMILL and UG/CAM are belongs to this kind of file.

Abstract: A new type of a 2-PRS/2-UPS 4-DOF parallel platform was introduced. The error model of the parallel worktable was established through the vector method. The effect of structural error, driving error, position error and clearance error of the joint point to the pose error of the moving platform can be analyzed. Error modeling provides theoretical foundation for design and error compensation of the parallel mechanism.

Abstract: Taking the spindle of machine tool as example,the modal analysis and harmonic response analysis were done by means of finite element method. Find out its characteristics of vibration modal. The analysis is conducive to the design of the spindle of machine tool. It makes a base for optimized design and remanufacturing.

Abstract: The modal analysis and harmonic response analysis of milling head box were done by means of finite element method. Find out its characteristics of vibration modal. The analysis is conducive to the design of the milling head box of machine tool. It makes a base for optimized design and remanufacturing.