Key Engineering Materials Vol. 693

Abstract: This for a spacecraft undergoing a continuous thruster maneuver, the spacecraft mass changes due to fuel consumption, and the liquid sloshing has time-varying property. However, the conventional applications in prior literature took these time-varying properties into consideration barely. The characteristics of residual fuel become an important drive for the coupled solid-liquid dynamics, especially in a partially filled tank. In this paper, dynamic equations of an equivalent pendulum model with variable parameters were developed by Lagrangian method. The calculation results showed that the time-varying properties influence the sloshing characteristics significantly. Finally, influences of draining flow rates, the thrust press during the sloshing motions, sloshing induced forces and torques were also investigated. The investigations here provided an effective way to deal with the delicate problem and to reveal the characteristics of the liquid sloshing dynamics in partially filled tank of a spacecraft.

Abstract: Based on open NC system architecture, embedded condition monitoring and diagnosis units were studied with the characteristics of modularization and reconfigurable. The intelligent measurement and control unit can be used to on-line monitoring, fault early warming, intelligent diagnosis and remote maintenance, it provied a solution for group integration monitoring system construction of high-grade NC machine. In this paper, the implementation and function of the intelligent measurement and control unit were introduced from 4 aspects including whole framework, hardware, software and XPE OS. An example of cutting force on-line monitoring were given, which operate well for alarming in unstable cutting condition.

Abstract: The wheat precision seeding technology provided an advanced agricultural protection for the high yield of wheat. But the lack of an effective agricultural machine made this technology difficult to apply widely. In this paper a quadruped wheel robot to achieve the wheat precision seeding technology was designed. And experimental study was taken under different operating conditions. Because of multiple effort factors, a quadratic orthogonal rotation combination design method was applied in the experiments, and identifying the main factors by analysis. Then the field test was carried out according to the main factors. The experiment results showed that the qualified rates of seeding exceed 93% in different sowing speed. That reached the agronomic requirements of wheat precision seeding.

Abstract: Motion axes should coordinate exactly in order to get high contouring accuracy. Gain matching is one of the coordinating problems. In this paper, gain matching effects on contouring accuracy are analyzed for both full-closed and half-closed control loop structures. A simple gain matching model is proposed in order to reduce the contouring error caused by unmatched gains of a multi-axis motion control system. According to this model, the contouring error can be reduced by tuning the proportional gain in the position loop of each axis. Finally, experiments are made to verify the proposed model, and the results show that the gain matching model can effectively reduce the contouring error of both linear and circular trajectory of motion control systems.

Abstract: In order to enhance energy recovering efficiency of regenerative braking system of electric vehicles (EV), coupling mechanism and decoupling method between braking system and charging system were studied. First, coupling-relation mathematical model between braking system and charging system of EV were built. On this basis, decoupling method was studied and mathematical model of decoupling was built as well. Furthermore, simulation model of EV was built, based on redeveloping the simulation software of ADVISOR. Finally, simulation of regenerative brake of EV was carried out under different working conditions. The results indicated that energy-recovering efficiency of EV based on decoupling strategy was better.

Abstract: Numerical control (NC) programming is the critical part for the NC manufacturing system. The NC manufacturing programming is the concentrated reflection of design of component-processing, which reflect directly the productive efficiency of NC manufacturing and the quality of products. This paper suggests that the Multi-agent as the theoretical basis and development platform to research the NC programming based on agent, in order to reach the autonomy of programming unit, the NC programming unit based agent as its the processing object, and self-organization of system. The NC programming based on Multi-agent can achieve the autonomy and functional maturation of each programming sub-unit, and can also achieve the coordination and cooperation among all the dependent units, therefore, the system processes the self-organization ability. One standard process template is created relay on this technology, in order to templatize and intelligentize the process flow and process data of NC manufacturing.

Abstract: Faced with the problem of generation for 3D machining process model, an approach to generate three dimensional machining process model according to information from design model based on definition is proposed. Compared with the existing methods, the approach utilizes multiple information of design model based on definition and takes many phases into consideration of 3D process model generation. The structure of 3D machining process model is defined and the course of 3D process model generation is researched, including multiple information acquirement, generation of procedure geometric models and annotation. Finally, the framework of system and application for 3D machining process model generation are presented for validation purposes.

Abstract: The initial gap in electrochemical machining (ECM) is a significant affection parameter for ECM process and machining stability. A tool setting detection system based on LabVIEW technology has been designed to realize the rapid and accurate pinpoint between two electrodes since the initial gap of micro-ECM is usually only a few microns to tens of microns. The system can not only efficiently complete tool setting detection in micro-ECM, but also real-time monitor the change of processing current. 120 comparative experiments have been conducted to evaluate the erosion amount of workpiece material, the reliability, repeatability and positioning accuracy of micro-ECM process in the conditions of wet tool setting compared with dry tool setting. The experimental results have shown that adopting the tool setting detection system designed in this paper, the erosion rates of cathode and anode after 120 repeated wet tool setting experiments were only 0.21% and 0.02%, the positioning accuracy and repeatability can completely meet the requirements of tool setting in micro-ECM, and greatly improve the efficiency of the micro-ECM.

Abstract: In view of the current welding industry, there is no automated programming tool for the welding path of square battery cover. According to differential geometry theory, the principle of nonlinear error is analyzed. Then a simplified model for nonlinear error is established. Based on these, an efficient algorithm based on nonlinear error is proposed. According to the proposed algorithm, two instantiation of the algorithm are presented. Therefore, the proposed algorithm is simple, reliable, and efficient. It adapts to the requirement of two mainstream spuare battery covers perfectly.

Abstract: Taking the CY4105 crankshaft mould as the research target, this paper introduced the CNC machining method based on CAD/CAM technique. At first, structure of the mould was introduced. Then, machining method was introduced, including blank setting method, cutting tool selection, machining method selection and technological parameters setting method. After that, generation method of the mould machining programs was introduced, including tool path and G codes generation. At last, the mould was machined by a vertical machining center, and the results show that the machining accuracy is high.