Abstract: The main research contents as well as the research status and results in fault diagnosis system for CNC Machine are reviewed, analyzed and summarized, based on the analysis of domestic and foreign literature in the field of fault diagnosis system for CNC Machine. It briefly analyzes the characteristic and applicability of Expert System, Neural Network, Fault Tree Analysis, Fuzzy Set Theory and Multi-Agent System, and points out the key technical problems which is needed to be solved in this field. Then it views the future development, and points that the fault diagnosis of integrated intelligence and remote network is the research and development trend of diagnosis system for CNC Machine.
Abstract: Sensorless induction motor drives are widely used in industry for their reliability and flexibility. It’s very important to improve the performance of speed estimation in some cases, especial at low speed of IM drives. The authors have proposed and developed a model reference adaptive system (MRAS) based on discrete time sliding mode algorithm(DTSM), which has high performance for sensorless induction motor drive in low speeds. The new algorithm obtains the identification flux using the classic MRAS, and the PI adaptive law in MRAS is replaced with the sliding mode observer which is acquired by the error function. This paper presents the theory, modelling, simulation and experimental results of the proposed DTSM-MRAS based sensorless direct torque control induction motor drives.
Abstract: Surface machining system based on spherical coordinate, which is used in non-contour control, is present for the thin-walled director sphere part turning, to improve the efficiency and quality of part machining. In this system, a thickness surface B-spline model is set up based on spherical coordinate, the space spiral path generation method is planned. To meet the requirement of surface quality, row spacing angle is determined by scallop height and blunt radius of cutting tool, and angle B-spline model for back cutting depth is given. Moreover, space spiral interpolation algorithm is present in CNC.
Abstract: The purpose of this research is to develop a control method that can provide an operator with a suitable force feeling for grasping fragile or soft objects so as not to totally crush them. This research examines a master-slave control system for a teleoperation construction robot in which a shovel with a fork glove, having four degree of freedom, is regarded as slave side and two joysticks are regarded as master side. In the previous study using a position-velocity control method, two joysticks manipulated the shovel according to the velocity of its piston. However, it was found that the reaction force to the joysticks in grasping fragile or soft objects was insufficient for operators and they were compelled to feel strange while moving the joysticks, because they had to remove the joystick to a middle position to avoid fully grasping the object. A position-force control method, in which the reaction force to the joystick is used as feedback instead of the velocity of a piston, is proposed to overcome the problems. Its effectiveness is verified by experiments of grasping a tin block and a urethane foam block.
Abstract: According to the practical operation of the hoisting multi-mobile robots system (HMRS), the cooperation localization and mapping is studied. Firstly, an improved algorithm of cooperation localization solution of multiple robot system is proposed based on map gridding algorithm. In addition, by virtue of sensor technology, the grid method is designed, which has the ability of accurate, reliable localization and rapid local mapping of the HMRS. Finally, simulation results demonstrate that the localization and mapping system is feasible and efficient.
Abstract: In order to improve the interference suppression capability for the muti-axle steering vehicle(MASV) and to reduce the design complexity of the controller , no steady-state error tracking control system was designed so that the contol system can meet the requirements of disturbance rejection and robust tracking. Using the no steady-state error tracking control strategy to the MASV, it can track reference signal perfectly. Its yaw angular velocity, sidesip angle and rolling angle are degraded at high vehicle speed. The stability and driving safety of the vehicle are improved. According to actual needs, the Parameter of the controller can be changed through the different characteristic value; The design and adjustment of the controller are simple amd easy.
Abstract: The dynamic model of multi-axle steering vehicle undertakes improvements, by taking the anterior axles mechanical steering on vehicle steering performance into account, that is to imply the front-axle wheel angle in control variable and to gear down the difficulty on vehicle control. On the basis of the revised dynamic model, the unit vector continuous robust control method, applied to multi-axle vehicle, is used to analyze the response characteristic of yaw rate and side slip angle under low and high speed. The paper analyzes the strength of unit vector continuous robust control method in multi-axle vehicle combined with minimum and maximum robust control method.The unit vector continuous robust control method for vehicle controling, as the analytical result shows, is able to control object quickly and has the characteristic of certain interference-free feature and higher vehicular control stability; the smaller wave of controlled variable which avoided the buzz of controlled variable, the smallness of control consumed energy, the easy realize of control favor the advance of vehicle economy.
Abstract: In this paper, the optimized point stabilization control of nonholonomic wheeled mobile robot has been researched, and point stabilization control of constraint nonholonomic wheeled system has been achieved through the geometry planning method based on Bézier, and constrained system is converted to un-constraint optimized question based on introducing penalty functions. The optimized control parameters has been got through Hooke-Jeeves method to achieve the perfect combination of the optimized route planning and optimized control, which can make the robot achieve the target pose under the constraint condition and improve the smooth of move path and reduce the stable time. The controller's validity is proved by the experiment.
Abstract: With the respect of the problem of that the control precision of air jet loom weft insertion control system can not satisfy the requirement of the high-speed loom, this article presented a high-precision weft insertion control system taking FPGA as the control core, and it designed hardware circuit and software framework. This control system generates weft insertion control signal which is figured out through the parallel execution of the FPGA program. The practice shows that the system owns the features of high control precision, good consistency and so on, and it has a significant importance to the high-speed development of air jet loom.
Abstract: Antimicrobial peptides (AMP) are potent, broad spectrum antibiotics which demonstrate potential as novel therapeutic agents. Because it is both time-consuming and laborious to identify new AMPs by experiment, this paper tries to resolve this problem by pattern recognition. Two major contents included: Firstly, up to six kinds of physicochemical properties value are selected to code the AMP sequence as physical-chemical property matrix (PCM), then auto and cross covariance transformation is performed to extract features from the PCM for AMP sequence expression; Secondly, these feature vectors are input to a powerful Support Vector Machine (SVM) classifier for training and new query AMP recognition. For a newly constructed AMP benchmark dataset, the overall classification accuracy about 96% has been achieved through the rigorous Leave-One-Out cross-validation. For convenience, a user-friendly web server, AMPpred, has been established at http://icpr.jci.jx.cn/bioinfo/AMPpred. It is anticipated that this on-line predictor may become a useful bioinformatics tool for molecular biology and drug development. Also, its novel approach will further stimulate the development of predicting peptide attributes.