Advanced Materials Research Vols. 139-141

Abstract: Steel portal frames have been widely designed and constructed in China since the end of the last century, and in recent years ERP management software systems have been used by more and more steel structure fabricators/constructors. This paper introduces the program principles and techniques of the development of integrated CAD software with ERP interface for the detailing design of steel portal frame structure, including the frame work, data structure, 3D modeling algorithm and automatic output of 2D drawings/ERP source data. In the system, steel members and connectors are modeled and visualized as 3D objects. All information, involving geometry, material, manufacturing, fabrication, installation, ERP data requirements and so on, are embedded in these 3D objects for the purpose of parametric modeling and subsequent data output. 3D solid model acts as the kernel of the system. Connectors of joints are classified and organized by way of logic hierarchy, 3D model of joint are assembled abide by the structural and geometric dependency relationship between connectors. The ERP data interface is embedded in the system. The raw data are directly extracted from the 3D model, then formatted and fed to certain ERP system.

Abstract: Considering the need of designing a parallel mechanism which can achieve a whole week of rotation and two translations, in this paper, the inverse dynamic model based on the virtual work principle was established. And because the maximum velocity and torque of servomotor are the key indices to choose the servomotor, the prediction models of the maximum velocity and torque of active joints employing the singular value decomposition technique were established as well; further, the prediction model of moment of inertia of servomotor was proposed, and then the computer simulation which can the indentify the effectiveness of this method was conducted. The estimating method has been successfully applied in the series of the parallel mechanisms.

Abstract: In this paper, the attempt was made to study dry WEDG (Wire Electrical Discharge Grinding), the differences between dry WEDG and wet WEDG, especially the rods appearance and material removal speed and surface roughness were studied experimentally, the results are as follow: (1) The shape especially the symmetry of the rods fabricated with WEDG using kerosene as dielectric fluid is better than that of dry WEDG only using pure air as dielectric. (2) The material removal speed is obviously higher in wet WEDG than that in dry WEDG. (3) The surface roughness of the rods fabricated with wet WEDG is lower than that with dry WEDG;.(4) The wet WEDG can be used in the roughness machining to improve the speed, and the dry WEDG can be used in the finishing machining to advance the surface quality.

Abstract: For filling the application requirement of searching toxic gas leak source, a multi-sensory robot, which is used for searching toxic gas leak source, is developed. This robot consists of humanoid multiple degree of freedom head system and tracked walking mechanism, with the sense of smell, hearing and stereo vision and other functions. The robot’s bionic olfaction system can detect 5 kinds of toxic gas in the same time, and the hearing system consisted of four microphones can get all kinds of sound in the general environment. Meanwhile, its binocular stereo vision system can get the 3D information of the work environmental. Distributed controll system is constructed for the robot, and comprehensive utilization of the multi-sensory function can increase the efficiency and accuracy of searching leakage. This robot can give full play the advantage of multiple degrees of freedom to expand the searching scope of the robot, and enhance the flexibility of the searching behavior. This robot system has wide application prospects in the environment of toxic gas.

Abstract: The voice interaction in cockpit mainly includes speech recognition, enhancement and synthesis. This interaction transfers the speech information to the corresponding orders to make machines in cockpit work unmistaken, also feedback the execution results to users by speech output devices or some other ways. The speech enhancement technology is studied in this paper, aiming at the Voice Interactive. We propose an improved spectral subtraction (SS) algorithm based on auditory masking effect, by using two steps SS. The simulated results based on the segment SNR compared to the traditional SS show the effectiveness and superiority of the improved algorithm.

Abstract: High pressure isolation plug train is a remote control, tetherless, highly piggable and high pressure isolation tool. The advantage of using the pressure isolation tool is to minimize production down time. Domestic research has started recently because of the foreign blockade of its core technologies, there are no relative products coming out currently. The smartplug that have been mentioned consist of plugging module, pigging module, hydraulic power module and communication and control module. The paper describes design ideas of each module in detail respectively and according to the design methods the prototype with diameter of 12 inches has been produced so far. Sealing pressure achieves 10Mpa by experiment. Looking forward to the technology would be applied in pipeline valve replacements and repairs, riser replacements and repairs, pressure test of risers and pipelines, midline pipeline repairs and relative engineering areas.

Abstract: This paper offers a robot calibration approach based on the virtual closed kinematic chain so that the absolute location accuracy of a robot can be improved. The calibration approach suggests that laser beam can be mounted on the robot’s end so as to form a virtual closed kinematic chain in the interest of enlarging the pose errors to proper extent, in this way straight line equations in space can be acquired when the robot positions are changed continuously, in the end the robots’ kinematic parameters can be figured out by genetic algorithm while measurement can be totally avoided in the calibration. Calibrating practices, simulating analysis and experiments on robots show that the approach can improve the absolute calibrating accuracy effectively.

Abstract: In the past decades, a number of parallel manipulators have been extensively studied. However, most efforts are dedicated to six degrees of freedom (DOF) or three-DOF manipulators. There is a need for equipment providing more than three DOF's arranged in parallel and based on simpler arrangements than six-DOF arrangements in application. This paper presents a novel four-DOF parallel platform manipulator with base mounted prismatic actuators. The manipulator is driven by four linear actuators. The movable platform of the manipulator can translate along two directions and rotate around two axes respectively. The kinematics model is formulated, which describes the inverse and forward kinematics transformation. It is very easy to develop a five-axis NC machine-tool which is of large-workspace based on the four-DOF parallel mechanism presented in this paper.

Abstract: The new type of pipeline-cleaning robot discussed in this paper is developed to clean pipelines within the diameter range 200mm-250mm, which is propelled by using screw locomotion. With the help of CATIA, the modeling & simulation software, the simulation model of the robot and its vibration analysis has been obtained. From the analysis, dynamic characteristics of pipeline robot vary with the output parameters of control module and the structures of robot joints. Stimulated vibration has very little influences on the whole machine. The stability and reliability of the robot have been proven. According to the experimental study of principle prototype and dynamic simulation study of the virtual prototype, dynamic characteristics can be improved by optimizing the structures of robot and the related output parameters of control module, which contributes to the improvement of its motion stability. Therefore, it is believed that the robot has great value in practical use.

Abstract: The new plane/space thermal cutting robot work station system for metal plate for a variety of two-dimensional (such as plane) and three-dimensional (such as Groove) cutting jobs, fully applies to the user on any graphics sheet metal cutting and cutting groove. It is based on robot and plane thermal cutting area or space thermal cutting area mature technology applications in the system. This article focuses on the new system composition and configuration, works, pneumatic control systems, robotics and controller applications, space thermal cutting control programming methods, etc. The new system, the higher degree of automation is a metal sheet processing. Through practical, cutting performance stable and reliable, the workpiece bulk cutting heterogeneity, significantly reducing the labor and improving productivity.