Automatic NC Research Articles

A novel integrating between tool path optimization using an ACO algorithm and interpreter for open architecture CNC system

This article proposes an effective methodology to reduce manufacturing time through the creation of quasi-optimal G command sequences, based on initial machining codes derived from CAD/CAM Service-Oriented Architecture (SOA) software. The optimization steps involved minimizing travel path time for CNC manufacturing machine milling and drilling. Also, identifying the optimal order of operation that enabled the shortest travel path for the cutting tool. These steps resulted in consistent enhancements of approximately 10.41% and 16.58% for milling and drilling machining, respectively. Furthermore, high-performing Ant Colony Optimization (ACO) algorithms were used to optimize the travel path time. In the context of automatic NC program production, the optimization of the cutting tool’s travel path could be achieved by integrating the ACO algorithm and the Open Architecture Control (OAC) into commercial CAD/CAM. In this paper, a new optimized generation of CNC systems, based on combining the Open Architecture Control (OAC) technology supported by the G-code data model and the optimization algorithm are presented.

Automatic NC Programming for Chamfering Addendum of Spiral Bevel Gear Based on UG/Open

A chamfering algorithm was put forward to achieve automatic NC programming for chamfering addendum of spiral bevel gears and a NC programming module was developed based on UG/Open through secondary development. Furthermore, a practical example was used to demonstrate the automatic NC code generation process for chamfering addendum according to the preset chamfer surface and its permissible error.

The Realization of Numerical Control Machining of 2D Parts Based on MasterCam FBM

Apply the function of FBM Mill and FBM Drill built in MasterCam to achieve the automatic NC programming and machining of solid parts.The feature modeling of parts is produced in Solidworks, and then converted to MasterCam. After the stock size of parts and FBM parameters are set, the features of parts are recognized automatically; and all of the 2D toolpaths of parts are automatically generated in a specified machine. Finally, the automatically generated NC toolpaths based on features are verified by simulating. FBM technology is adopted to eliminate the manual processes involved in identifying features for programming milling and drilling operations on solid parts, thus greatly increasing the efficiency and flexibility of programming, which is an effective method of achieving automatic NC programming.

On the Study of Automatic NC-Code Programming Based on DXF Files

In this paper, a method of automatic NC code programming is studied. The data structure used to store graph information is the base of automatic programming system. By utilizing the object-oriented tree data structure proposed in the paper, the disadvantages of the method caused by using simple data structures can be overcome. In processing information, the judgment of topological relationship between two outlines is very important. The Loop Extremum Method is easy, convenient and with no limitations. The system adds plenty of technological parameters, provides multiple machining patterns. In the end, an example is given to test and verify the system`s functions.

Research and Development of Four Axis Linkage Grinding Simulation System of Ball-Nose End Mill

The four axis linkage grinding simulation system of ball-nose end mill has be developed based on the mathematical model of four axis linkage grinding through establishing ball-nose end mill's parametrical database, constructing ball-nose end mill’s and grinding wheel's solid models in Solidworks, simulating the grinding processes of the rake face and flank face of ball-nose end mill based on Boolean operation, and automatic NC programming of rake face and flank face grinding. The results show the grinding simulation system can be used to manufacture ball end mill.

Optimization of Operation Sequence in CNC Machine Tools Using Genetic Algorithm

The productivity of machine tools is significantly improved by using microcomputer based CAD/CAM systems for NC program generation. Currently, many commercial CAD/CAM packages that provide automatic NC programming have been developed and applied to various cutting processes. Many cutting processes machined by CNC machine tools. In this paper, we attempt to find an efficient solution approach to determine the best sequence of operations for a set of operations that located in asymmetrical locations and different levels. In order to find the best sequence of operations that achieves the shortest cutting tool travel path (CTTP), genetic algorithm is introduced. After the sequence is optimized, the G-codes that use to code for the travel time is created. CTTP can be formulated as a special case of the traveling salesman problem (TSP). The incorporation of genetic algorithm and TSP can be included in the commercial CAD/CAM packages to optimize the CTTP during automatic generation of NC programs.

Research on Sawing and Milling Features and NC Programming of Plastic Door and Window

In this paper, the structure of plastic door and window and the characteristics of sawing and milling machining PVC profile are introduced, and on the basis of analyzing the relationship between function and kerfs of the window parts, the feature model of machining window profile is constructed, hereby making the geometry modeling and defining the essential elements of design feature make the process of automatic NC code generation simplified and its reliability strengthened.

310 A High-Efficiency Error Compensation System for CNC Multi-Axis Machines

To enhance a machine's ability for precision machining task, an efficient compensation scheme that takes all error sources into account is needed. In this study, an effective static/quasi-static error compensation system composed of an interpolation algorithm based on shape functions for error prediction, and a recursive software compensation procedure, was developed. The new error prediction scheme taking consideration of the fact that machine structure is non-rigid, is efficient enough to be implemented on-line. In addition, an automatic NC code converting software was also developed so that the developed system can be applied to practical machining for CNC multi-axis machines. A NC program identifying/rewriting system by C^<++> language was developed to identify and extract the nominal positions of cutter for processing error prediction and compensation. To verify the algorithm and system, cutting experiments were conducted, and the results have shown the success of the proposed error compensation system.

An efficient error compensation system for CNC multi-axis machines

To enhance a machine’s ability for a precision machining task, an efficient compensation scheme that takes all error sources into account is needed. In this study, an effective static/quasi-static error compensation system composed of an interpolation algorithm based on shape functions for error prediction, and a recursive software compensation procedure, was developed. The new error prediction scheme is efficient enough to be implemented on-line, taking into consideration the fact that the machine structure is non-rigid. In addition, an automatic NC code converting software was also developed so that the developed system could be applied to practical machining for CNC multi-axis machines. To verify the algorithm and system, cutting experiments were conducted, and the results have shown the success of the proposed error compensation system.

3-D object decomposition with extended octree model and its application in geometric simulation of NC machining

The paper discusses the development of a prototype solid modeling system based on the extended octree modeling approach and its applications in 3-D NC machining simulation and automatic verification. Along with a simple hierarchical data structure, the extended octree model uses the face boundary information (i) to represent complex objects, (ii) to improve object representational accuracy, and (iii) to accelerate the model updating procedures in a graphic simulation process. The improved representational accuracy makes it possible to carry out automatic NC program verification by generating the machined model of the part through the simulation and comparing it with the designed model of the part. The paper also addresses the issues of model conversions from CSG and B-Rep schemes to the corresponding extended octree models and the issues of carrying out Boolean operations on those extended octree models. A prototype system has been implemented and is integrated with AutoCAD AME solid modeler for object modeling and for NC simulation purpose.

Implementation of low-volume FMS for prismatic components

Fixture preparation and NC data generation are unavoidable operations for effective implementation of flexible manufacturing systems in high product mix and low-volume prismatic components. By developing new technologies for automatic fixture preparation and NC data generation, using flexible manufacturing systems should lead to high-efficiency manufacturing for small batches. Fixture-free machining, especially for block-like and plate-like components, was considered, and new machining centers were developed. The machining centers require CAD/CAM systems to automatically generate NC programs. By combining the machining centers and CAD/CAM systems, fully automated manufacturing can be performed for block-like and plate-like prismatic components. Research on fixture CAD/CAM systems to support the design of fixtures for complex prismatic workpieces, such as welded, forged, and cast materials, is also discussed.

旋削自動プログラミングにおける同時加工順序のプランニング

A method is proposed for planning an optimal machining sequence on automatic NC programming for turning. The method can determine a machining sequence which needs the least cutting time. In a process to determine the sequence, suitability of cutting conditions as well as interference between a tool and a workpiece is checked. A planning problem is represented as a graph based on the concept of cycle. In the graph, an optimal transition is found among sets consisting of machining processes. And an algorithm is proposed to solve the problem applying the dynamic programming of optimality. Numerical evaluation of the algorithm shows that it needs less calculating cost than exhaustive search and Dijkstra's algorithm to determine an optimal machining sequence. Machining sequences determined by the algorithm are compared with those determined by a skilled worker. As a result, machining sequences determined by the algorithm always had less or equal cutting time than those determined by a skilled worker.

Automatic cutter selection and optimal cutter path generation for prismatic parts

Abstract NC code generation, if done manually, forms the bottleneck in a production system. Hence automatic NC code generation forms an important part of a totally automated manufacturing system. Most of the existing systems for this task consider cutter path generation only for limited part geometry. The work proposed here considers both optimum cutter size selection and cutter path generation. The work done encompasses almost all the features found on prismatic parts, such as slots, steps, projections, etc. First the finishing and roughing tools are selected based on minimum cutter motion criterion, then algorithms for determining the area within the cutter centre can move are outlined. The final part of the research deals with optimizing the cutter movement within this region. So here we have developed the algorithms to select an appropriate cutter and also to generate the cutter path and NC code for machining a pocket using any given cutter.

An integrated CAD/CAPP/CAM system based on form feature oriented product model

Form feature based product modelling technique is the basis of integration of CIMS information system. On this basis, an integrated CAD/CAPP/CAM prototype system called HFCIM has been developed by authors. Some main principles used in this system will be discussed. At first, the structure of product model is described in section 2. In section 3, The feature based product modelling system is described. A prototype process planning expert system is described in section 4. The principles of automatic NC programming system based on product model is described in section 5.

NC programming and machining of sculptured surfaces

A three-dimensional automatic NC programming system is presented. To make the system for general purpose use, a classification of geometric models is developed and described in detail. The strategy and algorithm of matching B-Spline curves with COONS surface is proposed here.

NC programming and machining of sculptured surfaces

A three-dimensional automatic NC programming system is presented. To make the system for general purpose use, a classification of geometric models is developed and described in detail. The strategy and algorithm of matching B-Spline curves with COONS surface is proposed here.

A Padl-Based Numerical Control Machining Data Generation Program

This paper describes an automatic NC machining data generation program based on the PADL data base. PADL, an acronym for Part and Assembly Description Language developed at the University of Rochester, U.S.A., is a shape description system based on the principles of constructive solid geometry. It has definitional facilities for describing the shape of a part or an assembly of parts and commands for displaying them on the screen. The NC data generation program presented in this paper is an extension of PADL's capability for manufacturing applications. It makes use of the PADL boundary file (a tree-structured geometric data base) to establish a set of control surfaces to guide the cutter motions. There are six machining commands to handle point-to-point operations, 2-D contouring, and 2-1/2-D pocketing. A transition matrix is used to parse the input commands of machining functions. The part to be machined and cutter paths are displayed on a graphic screen.