IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

IPPS_R : a generative process planning system for rotational parts

An automated machining process planning system for rotational parts is designed, developed and implemented. The system is called IPPS_R for Intelligent Process Planning System for Rotational parts. The IPPS_R system is designed for generating process plans for manufacturing rotational parts using metal cutting operations. A generative approach is employed to determine process operations and sequences automatically. For each machining feature, based on the accuracy and surface quality requirements, a fuzzy logic approach is developed to generate machining operations. A method of ranking the machining priorities of the features according to the feature relationship matrix is developed for sequencing operations. Moreover, the heuristic search of process plans is achieved by minimizing the number of setups in a plan. Finally, the IPPS_R system with a user-friendly interface is implemented in Microsoft Visual C++ on a personal computer, utilizing Microsoft Foundation Class (MFC). Two sample parts are used to demonstrate applications of the IPPS_R system.

A Digital Twin of Multi-Axis Machine Tool for Micro Process Planning

Achieving high performance of machining production systems requires the use of multi-axis machine tools. In order to maximize the performance of multi-axis machine tools, micro process planning for creating machining data is important. Many researches on micro process planning mainly focused on 3-axis machining. As promising approaches among them, a micro process planning system was proposed that reuses actual machining cases and analyzes case data to derive the necessary rules. However, it is not always effective for multi-axis machining, because enough case data are not collected for micro process planning of a specific multi-axis machine tool. In this study, a digital twin of multi-axis machine tool in cyberspace is proposed to collect real and virtual machining case data for micro process planning.

An assembling algorithm for fixture in an assembly process planning system

Three-dimensional assembly process planning is a precondition for achieving full product lifecycle management based on three-dimensional modelling. Information expression and management operations of fixture models are key to three-dimensional assembly process planning systems. To reasonably and efficiently achieve the goal of planning assembly processes with a fixture model, the application of a fixture information model to a three-dimensional assembly process planning system is investigated. First, to manage tooling information, a fixture information model is defined that consists of management information, display information, geometric information, assembly constraints and degrees of freedom. Then, based on the analysis of the degrees of freedom of components and the assembly constraint relationship, a method of solving assembly constraints based on degrees of freedom reasoning is proposed. Finally, by using the method of solving assembly positioning based on geometric constraints, the pose transformation and assembly positioning of parts are achieved. Through the development of a tooling function module, the three-dimensional assembly process planning system is improved. The feasibility of the above method is verified using part of a spacecraft as an example.

Automated Process Planning System for End Milling Operation Constrained by Geometric Dimensioning and Tolerancing (GD&T)

To realize autonomous machining, it is necessary to focus on machining tools and also on the automation of process planning in the preparation stage. This study proposes a process planning system that automatically defines the machining region and determines the machining sequence. Although previous studies have explored computer-aided process planning, only a few have considered geometric tolerances. Geometric tolerances are indicated on product drawings to eliminate their ambiguity and manage machining quality. Geometric dimensioning and tolerancing (GD&T) is a geometric tolerance standard applied to a three-dimensional computer-aided design (3D CAD) model and are expected to be used for the digitization of manufacturing. Therefore, this study developed an automated process planning system by using GD&T as a sequencing constraint. In the proposed system, the machining sequence is automatically determined by the geometrical constraints, which indicate whether the tool can approach, and GD&T, which indicates the geometric tolerance and datum in a 3D CAD model. A case study validated the proposed method of automated process planning constrained by GD&T. The result shows that the proposed system can automatically determine the machining sequence according to the geometric tolerance in a 3D CAD model.