Applied Mechanics and Materials Vol. 251

Abstract: The paper firstly built a mode of a forging manipulator gripping mechanism. Then the clamping fore, connecting rod force and clamp arm force of which were calculated by the static analysis function of Pro/Engineer. Finally, conclusions were made based on the results analysis of the data processing which were fitted in MATLAB.

Abstract: The existence of clearance in joints of manipulator system is inevitable and the movements of the real manipulator are deflection from the ideal manipulator for the clearances. In this study, the effects of clearance on dynamic responses of real manipulator system with multiple clearance joints are investigated using a computational methodology. By applying the nonlinear continuous contact force model, the contact dynamics model in joint clearance is established and the friction effect is considered with the help of Coulomb friction model. Then the dynamics simulation is carried out and the dynamic characteristics of manipulator system with multiple clearance joints are investigated. The results show that the clearance leads to degradation of dynamic performance of the real manipulator system.

Abstract: The regular current collection is very important for high-speed train， and can be obviously improved by the use of active control. In order to study the impact of the fuzzy active control on pantograph-catenary system, the model ohe simulation model is created with the software of simulink. Finally the influences of fuzzy active control on dynamic performances and quality of current collection of the pantograph-catenary system are analyzed. It seems that, the performances of the system with or without active control is established, the fuzzy controller is constructed, and tf the pantograph- catenary system can be improved obviously under the fuzzy active control, the maximum value of the contact force is reduced to 50 percent, the minimum is increased to 80 percent, and the fluctuation extent of the contact force is reduced to 70 percent.

Abstract: The arm of robot consists of a manipulator and an end-effector. The end-effector is doing a specific work such as welding, picking and placing, sawing, deburring, suction, etc. with for the specific object of robot system. Here we are focused on the gripper among end-effectors. If the gripper generates the excessive gripping force, then the gripped material can have a permanent deformation. On the other hand, if the gripping force is too small, then the gripped material can be slip from the end-effector, drop to the floor and will get damaged. Therefore, it is important to use the adequate gripping force of the gripper. In this paper, we suggest the algorithm which is easy to automate, for the extraction of optimal gripping force range, with the estimation of frictional coefficient and young’s modulus.

Abstract: Based on analyzing the existing algorithms, a novel tool path generation of 2D contour considering stock boundary is presented. Firstly the boundary points of stock are obtained by three-dimensional measuring machine. And the boundary curve is constructed by method of features identifying. The stock boundary is offset toward outside with tool diameter. An enclosed region is formed between the contour curves and the offset curves of stock boundary. The tool path is generated by form of parallel spiral by offsetting the stock boundary in the enclosed region. Finally the validity of present method is demonstrated by an example.

Abstract: Analytical solution of the free vibration of the isosceles right triangle membrane with several different boundary conditions was obtained. Some qualities of the solution were studied, especially, the completeness’s of the analytical solution were proved.

Abstract: The anchor assembly is the important part of the hydraulic lift, the stresses of which under load are analyzed using finite element method. The 3D mechanical models of anchor assembly are created with different sizes. Several important positions are investigated around the holes of upper anchor and these stresses are compared between different cases. Based upon the numerical results, the safety assessment of the anchor assembly is conducted and a reasonable design scheme is proposed.

Abstract: In every field which needs data processing, the sparseness of data is an essential problem that should be resolved, especially in movies, shopping sites. The users with the same commodity preferences makes the data evaluation valuable. Otherwise, without any evaluation of information, it will result in sparse distribution of the entire data obtained. This article introduces a collaborative filtering technology used in sparse data processing methods - project-based rating prediction algorithm, and extends it to the areas of rough set, the sparse information table processing, rough set data preprocessing sparse issues.

Abstract: In this paper, the context of relative kinematic modeling, and the analysis of symmetric dual four-bar mechanism industrial robot are introduced. For such mechanism, its designation of the representative algorithm, and its simplification, simulation, verification and alternately analysis in Forward Kinematics Problems (FKP) and Inverse Kinematics Problem (IKP) were studied. Via such method, it’s possible to efficiently analyze and solve the both of FKP and IKP of symmetric dual planar four-bar mechanism. Thus this method can be applied for the design, simulation and verification for the robot with similar structure.

Abstract: All-Electric Subsea Production Control System, which has many advantages over conventional Multiple Electric-hydraulic control system, is the development tendency of subsea production control system. Being based on principle of all-electric control system, its advantages, working principle and key technologies were analyzed in this paper, which could be a reference for further study.