Advanced Materials Research Vols. 694-697

Abstract: This paper presents an optimization method for redundant manipulator redundancy resolution with additional task. The cost function is a compromise between the requirement of accuracy of the main task, the accuracy of the additional task, and the feasibility of the joint velocities. The joint rates that minimize the cost function can be found, and the joint position trajectories can be integrated with an initial configuration. The effectiveness of this presented method is verified by a planar 3-DoF PRR manipulator.

Abstract: Reliability analysis methods of reliability prediction have been simply introduced in the paper. In the light of the CNC machine tools, we can design and direct and find the poor reliability parts. Relevant promotion will be carried out to increase the reliability of the CNC machine tools.

Abstract: A new flexible positioning system is developed to fulfill the mixed model production in a car body in white (BIW) welding production line, which is able to respond quickly market needs and shorten the cycle time of auto model update and improve productivity. The system architecture is researched and developed, and the execution unit and motion control unit is discussed. System motion control is realized by means of industrial Ethernet network and SERCOS communication protocol.

Abstract: Geometric errors of a machining center can cause great influence on machining accuracy, and these geometric errors should be identified and compensated in the actual working conditions. Taking a three-axis vertical machining center as example, 21 geometric errors of the machine tool were solved. By using the 12-line method based on a laser interferometer, identification principle of the positioning errors, straightness errors, pitch errors, yaw errors, roll errors and squareness errors are presented, and all of the 21 geometric errors of the machining center were identified. Geometric errors having great influence effect on machining accuracy can be identified. The research results provide guidance for analyze of geometric errors of machining center.

Abstract: A CNC controlled Multi-Tip Tool Structure for fastturning process is presented in this paper, to prolong overall tool life aswell as to shorten machining time. Instead of one cutting edge in regularturning process, several cutting tools are used simultaneously in thisassembly. With this arrangement, radial cutting forces are balanced with eachother and the steady or follower rests in a regular lathe can be eliminated,for long and thin work pieces. Make the tooling structure more compact and morefeasible for multi-head CNC lathe or combo machining.

Abstract: In light of the characteristics and small samples of the research of the CNC machine tools based on Weibull distributions，dynamic modeling and middle rank are used to evaluate the failure rate of each test phase. Traditional Duane model are referred to fit parameters of the reliability growth model with least squares.

Abstract: The dig rod process is the first step during the processing of sapphire. The Sapphire crystal lump cracks, the tool chipping and the low processing efficiency are the three common problems during the dig rod process. To solve these problems, developed the control system of the Sapphire dig rods machine based on the Z3050 rocker drill , applied fuzzy adaptive PID controller to detect the tool torque and adjust the tool feed rate real-timely, realized constant pressure closed-loop control, the experimental prototype successfully applied in the actual production. This paper introduces the composition, the principle of the system and its actual production.

Abstract: The volumetric errors modal is built with the coordinate errors of each axis of CNC machine tool through the laser interferometer. The volumetric errors in the workspace are calculated with the errors prediction modal. With the calculated results of volumetric errors, the errors tendency of CNC machine tool can be predicted. Besides, the specific accuracy testing projects can be conducted by the errors areas taken care more. The main errors of CNC machine tool will be tested rapidly and efficiently.

Abstract: Accelerating axle gear-shift hole processing technique of CNC equipment headstock was improved for gear colliding with housing wall during processing, interference phenomenon, galling and surface quality during scrapping plane. Experience proves that the machining process improvement of the accelerating shaft shift holes of the headstock is very successful and the product bottleneck effect is eliminated.

Abstract: Basic principle and methods of Go-Flow methodology have been introduced. In light of the characteristics and analysis demands for CNC machine tools, methods and procedures to evaluate the reliability of CNC machine tools have been put forward.