[Show abstract][Hide abstract] ABSTRACT: To improve five-axis machine's efficiency and machining accuracy, a new cross quadrant angle processing algorithm has been raised in this paper while the existing post processing algorithm can’t solve the problem of cross quadrant processing rotation angle good enough. The machine's rotation axis's movement is divided into four cases in this algorithm, and the most optimal rotation angle can be calculated according to the constraint conditions of the shortest rotating path and the rotation angle of B axis can’t be over travel. To solve the problem of synthetic sports deviation programming straight line because of the rotation movement in five-axis machining, the method of using RTCP and RPCP algorithm to program is put forward. In the end, correctness and superiority including cross quadrant angle processing algorithm raised and programming by using RPCP method in the form of double turntable are validated by simulation experiment.
Preview · Article · Dec 2011 · Procedia Engineering
[Show abstract][Hide abstract] ABSTRACT: To meet the need of advanced manufacturing technique, an open computer numerical control (CNC) software package for CNC machining is developed. Module library of the software package was of tree structure with a depth of 5. Terminal nodes of the tree were module units with unambiguous functions. Module units which dealt with real-time tasks were developed adopting real-time dynamical linked library (RTDLL), and non-real-time module units were developed with component object model (COM). CNC controllers for various machine tools could be built with the software package. The controllerspsila external interfaces were coincident with the serial real-time communication system (SERCOS) international standards, and the internal interfaces followed the open modular architecture controller (OMAC) agreement. Motion controllers for 3-axis linkage milling machine tools and for 5-axis linkage milling machine tools were built using the software package. It is shown by experiments that controllers built can be used for motion control of CNC machine tools and CNC machine tools with the controllers have good processing performances.
[Show abstract][Hide abstract] ABSTRACT: To improve production rates and the economic benefits, process parameters need to be monitored and adjusted automatically in the machining. At present, it is mainly concentrated on the study of the algorithms about tool wearing and tool breakage, and theory modeling of interrelated models in the processing machining. The monitoring systems independent of CNC are also investigated to realize the status monitoring on external parts, which result in lower integration and difficulty in operation. Consequently, a modular and configurable machining system of three axis milling is established, with the ability of constant cutting force, which is a part of CNC system and can coordinate with traditional CNC to implement the function of integration state monitoring. With this system it can realize the real time status monitoring in machining, and improve the work-piece's quality and efficiency by controlling the constant cutting force between the work-piece and the tool.
[Show abstract][Hide abstract] ABSTRACT: In this paper, a motion controller for computerized numerical control (CNC) machining is developed in accordance with open modular architecture controllers (OMAC) agreement and industry standards. The motion controller is a software package running on personal computer. It is developed based on modular structure adopting hierarchic organization mode. After analysis of software and hardware structure of common CNC machine tools, the motion controller is divided into series of module units. Dynamical behaviors of the controller are described using hierarchic finite state machine (FSM). Reconfigurable controller is realized through setting customizable parameters, appointing rules in module units naming, designing communication interfaces between modules and prescribing format of configuration file. The open architecture motion controller developed has characteristics of user-oriented modules and reconfigurable software, compared with the traditional CNC system of close structure. Besides increasing the degree of reusability and openness, application of above-mentioned open architecture motion controller leads to significant decrease of development time and maintenance cost.
[Show abstract][Hide abstract] ABSTRACT: In the machining, process parameters need to be monitored and adjusted automatically, which can improve production quality and reduce machining time. At present, it is mainly concentrated on the study of some algorithms about tool wearing and tool breakage, or theory modeling of interrelated models in the processing machining. The monitoring systems independent of CNC are also investigated to realize the status monitoring on external parts, which result in lower integration and difficulty in operation. Consequently, an integrated controller of five axis milling, which is modular and configurable, is established. Its composition and control flow have been introduced in detail. This controller has the ability of keeping constant cutting force, adjusting feed-rate intelligently, which is a part of CNC system. With this system it can realize the real time status monitoring in machining, and improve the work-piece's quality and efficiency in rough milling. At last, the operating principle of the intelligent algorithm in this controller has been described.
[Show abstract][Hide abstract] ABSTRACT: The current 5-axis coordinated linear interpolation method results in low-speed, low-accuracy and enormous numerical control (NC) files in sculptured surface machining. An instruction format with AKIMA spline curves suitable for 5-axis coordinated real-time interpolation is presented by making use of the advantages of AKIMA curves to represent spatial curves. Curve through position vectors in the machining path is constructed using AKIMA spline method. The related orientation vector to each position vector is calculated by angles of the machine tool rotation axis. Then curve through orientation vectors is achieved by AKIMA method too. Real-time interpolation of these curves is accomplished with a method of truncated Taylor series expansion. A controller with this interpolation method is developed in an open computer numerical control (CNC) system developed by ourselves. The performance of the proposed controller is demonstrated using a practical example.