Advanced Materials Research Vol. 842

Abstract: As space robots gain more and more importance in space operations, it was becoming imperative to understand their distinctive dynamics. The dynamics model of the space flexible robots is very complex, and the differential equation derived from dynamics was solved difficultly and slowly. In this paper the efficient recursive O(n) dynamics algorithm of space flexible robots systems with rigid base and flexible manipulators was discussed, and the fast efficient integration method was used to solve this dynamics equation for real time simulation. Simulations results show that the dynamic modeling and fast efficient numerical integration techniques of flexible space robot proposed in this paper are very useful. Keyword: space robots;efficient dynamic; recursive; real time simulation

Abstract: The basic composition and working principle of the turret punch press were analyzed, the recent distance method and genetic algorithm optimize method of holes machining path of NC turret punch press was put forward, the corresponding mathematical model and optimization algorithm was respectively given, these two kinds of optimization methods aiming at different types of holes are compared with the examples, put forward a kind of the integrated holes machining path optimization.

Abstract: According to the requirement of automatization of drainpipe deposit cleaning work in the municipal engineering works, a kind of robot for work of drainpipe deposit cleaning has been researched and manufactured with the simulation analysis and technique of virtual prototyping. In article the composition principle and key techniques of the robot are introduced in detail, including technique of adapting and adjusting the change of pipe diameter, technique of obstacle crossing, technique of walking and driving and so on. The manufactured prototype and results of tests show that the robot possesses characteristics, such as adapting range of pipe diameter is between 400~500mm, the walk speed when working is 2m/min, the drag force could reach 3000N above, and the walk distance could reach 1000m..

Abstract: This paper proposes a novel architecture for a biped robot with six DOFs per leg and an active toe DOF (Degrees of Freedom). The arrangement of three successive DOFs paralleled to each other makes its inverse kinematics simple and decoupled by omitting one DOF which is unnecessary when walking. And this work presents close equations for the forward and inverse kinematics. The results can be used in the kinematic control study of the robot.

Abstract: High contact stress between the vane tips and the cam ring is one of the main obstacles to improve the working pressure of a water hydraulic vane pump. A pressure-reducing valve for regulating the bottom pressure of the vanes at the pump suction zone is presented in this paper. Through optimization and simulation, it is found that the throttle structure has great influence on the dynamic performance of the pressure-reducing valve, and the triangular-rectangular groove is proved to be more suitable for the valve among all the investigated grooves. The theoretical analysis results show that the use of the pressure reducing valve can obviously reduce the contact forces between the cam ring and the vanes at the suction zone of the pump. The work in this research provides a feasible solution to improve the working pressure of a water hydraulic vane pump.

Abstract: Fluid-borne noise in piston pump is an important issue that has not been solved well until now. To reduce the vibration and noise of a water hydraulic piston pump, a port plate with a closed-compression angle and a silencing groove was designed for the pre-compression process. Three types of grooves were selected as the silencing structures and investigated in this paper. Through multi-objective optimization based on genetic algorithm, it is found that the port plate with the combination of a closed-compression angle and a silencing groove has better silencing effect than that without a closed-compression angle, due to its ability of simultaneously balancing the pressure gradient in the pre-compression process and the output flow pulsation of the pump. In this case, U-shaped groove with the angle is superior to the other two types in reducing the pump noise. This work presents an effective method for solving the fluid-borne noise of hydraulic piston pump.

Abstract: Taking the generator and turbine as an integrated system, the nonlinear coupling dynamic equations of the system are established by the finite element method. According to the dynamic equations, the global coupling relations among the structural parameters, fluid parameters and electromagnetic parameters are discovered. Based on the dynamic equations, the dynamic responses of the system are calculated and analyzed. The results show that not only the structural parameters, but also the fluid parameters and the electromagnetic parameters have significant effects on the dynamic responses of the system. Finally, an example is presented.

Abstract: Shakedown analysis is important for branch pipe because it is often damaged under various water pressure. In this paper, an element bearing ratio (EBR) based shakedown analysis method is employed for shakedown analysis of branch pipe. The EBR is used to replace the stress term in classical optimization problem in the procedure, and series of residual EBR fields can be generated by the D-value of the elastic-plastic EBR fields and the elastic EBR fields at every incremental loading step. The shakedown load is determined by performing an incremental non-linear static analysis when the yield criterion is arrived either by the elastic-plastic EBR fields or residual EBR fields. By introducing the EBR, the proposed procedure can be easily used to shakedown analysis of branch pipe with multi-material and complicated configuration. Numerical examples validate the method and demonstrate its performance.

Abstract: Mine man-car skip underframe is one of key components of mine hoisting system, in order to obtain the optimal structure and function characteristics, the finite element analysis method based on ANSYS is used to make static and modal analysis for the mine slope ramp man-car skip underframe. Static analysis shows that: The strength of underframe under typical working conditions meets requirements, but the stress surplus is relatively large. Modal analysis indicates that: It's prone to have bend and torsional deflection between the 4th and 5th beam, and the free modal shape has saltation. According to the above finite element analysis results, corresponding structure optimization is made on the underframe section size and the position of beams. The optimizing results show that: The stress amplitude of structural optimized underframe increases by 16.9%, the stress surplus effectively reduces, and the weight of underframe decreases by 10.6%. The free modal shape is more smooth, vibration mode has no saltation, and the dynamic performance is improved.

Abstract: As the main production equipment in the machinery industry, machining center (MC) market is active, it is urgent to enhance its development and design ability. Product platform can be a good solution to this problem. In the constructing process, market segmentation grid of MC was created firstly, variants and part of future uncertainties were identified at the same time. Then the unknown uncertainties related to customer needs were analyzed to find out the key design parameters. Through the mapping between the parameters and structure, the critical flexible modules were determined. Finally, the flexible product platform was constructed by extracting the common and the flexible modules. Keywords: MC; Flexible product platform; Platform planning; Flexible modules