Key Engineering Materials Vol. 584

Abstract: This paper introduces a novel experiment platform for AC speed control system based on TMS320LF2407A. The system composition and the design method of hardware and software function modules are set forth. In this experimental platform, Users can carry out the experiments of many kinds of motor control strategy for induction motor, synchronous motor and the other motors. This experimental platform is transparent to hardware and is open to software system, and achieved good results in the practical teaching and research.

Abstract: PLC module is an important part of embedded NC system, and mainly accomplishes the auxiliary functions of CNC machine tools. This paper completes the work of research and development of the PLC programming software for PC side of the host computer, and the software is developed in VC++6.0 environment based on windows XP system, to realize the editing functions and the mutual conversion between the ladder and instruction language. Focus on the realization of the mutual conversion between ladder with instruction table, use the logical structure of tree when the ladder converts to the instruction table, and use the data structure of stack to complete the conversion. Instruction table is transformed to Ladder by the operation of the stack to complete the conversion.

Abstract: In view of the current trajectories connecting with straight line, the methods of transfer and error analysis are elaborated in detail. To the errors caused by current trajectories connecting with straight line, analysis of the relationship between transfer error and interpolation surplus coupled with the angle is explained. And the explanation is according to the different angles between velocity vectors.

Abstract: At present, the mobile refuge chambers are mostly used square or circular structures. Based on these researches, a new chamber structure is presented in this paper, which is square and circular combined structure. The size and connection way are designed through the analysis of the working conditions and the requirements of the installation, transportation, maintenance and so on. Then the new structure is simplified to four kinds of cabin model, which can be analyzed by the ANSYS software. By the simulation analysis the reliability of the new structure is determined, which provides a theoretical basis for guiding the structural design of the mobile refuge chamber.

Abstract: Currently the speed estimation methods for control system of speed sensorless are sensitive to changes in the motor stator resistance, and have poor robustness. This paper is proposed a method to obtain the motor speed: by using the stator quadrature axis current and speed equations in permanent magnet synchronous motor, to construct a linear dimensionality reduction Luenberger observer. The notable features of this method are the fast tracking speed and torque response. Finally by applying Matlab simulation and experiments, to verify the effectiveness and feasibility of this system design.

Abstract: The final process of workpiece is composed of a series of connected trajectories, and the expectation speed of the different trajectories may be different, so it requires the changes of acceleration and deceleration speed. This paper introduces the improved acceleration-deceleration algorithm of trigonometric function, and presents an optimization algorithm according to the changing trend of velocity to the method of forward-looking processing speed.

Abstract: Based on production needs, a main transmission mechanism of underdrive speed press was designed in this paper. The design of the main transmission mechanism is the improvements and alternative of sine institutions slider-crank mechanism made. Underdrive and dual slider mechanism were designed, in order to achieve the presses punching process. The nominal pressure angle and the nominal torque were calculated. A preliminary calculation and design of the crankshaft, bearings, slider of the main drive mechanism. Ensure reliable operation and to provide a basis for the optimization design.

Abstract: Based on VB, start from the performance requirements of ultrasonic honing for the amplitude transformer, and derive the amplitude transformer wave equation and boundary conditions. Then, establish a resonance frequency equation, programming iterating the critical size of the Amplitude transformer. To get the optimal solution, verified the results of optimal design by experiment. Experiments show that the optimal design is feasible, fast and accurate, possess of great practical value. It has played a prominent effect for further optimal design and processing applications of ultrasonic honing.

Abstract: Space manipulator is an important tool for spacecraft to complete a variety of tasks in space. The trajectory precision of the manipulator determines whether the mechanism performs normally. Nowadays the harmonic drive is widely used as the reducer in the space manipulator, which may influence the dynamical properties of the flexible space manipulator. This paper establishes the dynamical models of space manipulator considering the harmonic hysteresis phenomenon derived from the harmonic reducer. A numerical simulation is proposed to analyze the nonlinear dynamic characteristics of flexible space manipulator with harmonic drive. The results of angular velocities reveal that non-linear and high-frequency disturbance detected in the output dynamical property is caused by flexibility of the space manipulator. Moreover, the observed hysteresis phenomenon in the dynamic behavior is not only determined by the flexibility of manipulator but the transmission feature embedded the harmonic drive.

Abstract: From the middle of the 20th century, CNC(Computer numerical control) machine tool has brought a revolutionary change to the mechanical manufacturing industry. CNC machine tool is a kind of highly mechatronics product. It has the Characteristic of high precision and high productivity. Therefore it develops quite fast and improves various kind of the quality of the products. It speeds up the development of machinery industry. In order to meet the requirements of the processing accuracy and speed of modern society, the structure and components of the machine have also become complicated. In order to protect the safety of operators and reduce time of machine repaired as well as improve efficiency, the requirements of the reliability of CNC machine tool should be greatly improved. This study will briefly introduce the concept of reliability and put forward some measures to improve the reliability.