Tool path optimization for free form surface machining

CIRP Annals ◽  
2009 ◽  
Vol 58 (1) ◽  
pp. 101-104 ◽  
Author(s):  
I. Lazoglu ◽  
C. Manav ◽  
Y. Murtezaoglu
Author(s):  
Tomonobu Suzuki ◽  
Koichi Morishige

Abstract This study aimed to improve the efficiency of free-form surface machining by using a five-axis controlled machine tool and a barrel tool. The barrel tool has cutting edges, with curvature smaller than the radius, increasing the pick feed width compared with a conventional ball end mill of the same tool radius. As a result, the machining efficiency can be improved; however, the cost of the barrel tool is high and difficult to reground. In this study, a method to obtain the cutting points that make the cusp height below the target value is proposed. Moreover, a method to improve the tool life by continuously and uniformly changing the contact point on the cutting edge is proposed. The usefulness of the developed method is confirmed through machining simulations.


Author(s):  
Feiyan Han ◽  
Juan Wei ◽  
Bin Feng ◽  
Wu Zhang

The manufacturing technology of an integral impeller is an important indicator for measuring the manufacturing capability of a country. Its manufacturing process involves complex free-form surface machining, a time consuming and error-prone process, and the tool path planning is considered as a critical issue of free-form surface machining but still lacks a systematic solution. In this paper, aiming at the tool path planning of the impeller channel, a quasi-triangular tool path planning method based on parametric domain template trajectory mapping is proposed. The main idea is to map the template trajectory to physical domain by using the mapping model of parametric domain to the physical domain to obtain the actual machining path. Firstly, the trajectory mapping model of parametric domain to physical domain is established using the morphing technique, and the template trajectory mapping method in the parametric domain is given. Secondly, the clean-up boundary of the impeller channel is determined in the parametric domain, and the quasi-triangular template trajectory of the impeller channel is defined. Finally, taking a certain type of impeller as an example, the quasi-triangular tool path of the impeller channel is calculated, and the tool path calculation time of this method is compared with that of the traditional isometric offset method. The result shows that the computational efficiency is improved by 45% with this method, which provides a new method for the rapid acquisition of NC machining tool path for impeller channels. In addition, the simulation and actual machining are carried out, the results show that the shape of actual cutting traces on the surface of the impeller channel is quasi-triangular, showing that this method is effective and feasible.


Author(s):  
Lu Lei ◽  
Jiong Zhang ◽  
Xiaoqing Tian ◽  
Jiang Han ◽  
Hao Wang

Abstract This paper develops a tool path optimization method for robot surface machining by sampling-based motion planning algorithms. In the surface machining process, the tool-tip position needs to strictly follow the tool path curve and the posture of the tool axis should be limited in a certain range. But the industrial robot has at least six degrees of freedom (Dof) and has redundant Dofs for surface machining. Therefore, the tool motion of surface machining can be optimized using the redundant Dofs considering the tool path constraints and limits of the tool axis orientation. Due to the complexity of the problem, the sampling-based motion planning method has been chosen to find the solution, which randomly explores the configuration space of the robot and generates a discrete path of valid robot state. During the solving process, the joint space of the robot is chosen as the configuration space of the problem and the constraints for the tool-tip following requirements are in the operation space. Combined with general collision checking, the limited region of the tool axis vector is used to verify the state's validity of the configuration space. In the optimization process, the sum of path length of each joint of the robot is set as the optimization objective. The algorithm is developed based on the open motion planning library (OMPL) which contains the state-of-the-art sampling-based motion planners. Finally, two examples are used to demonstrate the effectiveness and optimality of the method.


2008 ◽  
Vol 392-394 ◽  
pp. 211-215
Author(s):  
Li Qiang Zhang ◽  
Yu Han Wang ◽  
Ming Chen

In free-form surface machining, it is essential to optimize the feedrate in order to improve the machining efficiency. Conservative constant feedrate values have been mostly used since there was a lack of physical models and optimization tools for the machining processes. The overall goal of this research is the integration of geometric and mechanistic milling models for force prediction and feedrate scheduling for free-form surface machining. For each tool move a geometric model calculates the cutting geometry parameters, then a mechanistic model uses this information with the constraint force to calculate desired feedrates. The feedrate is written into the part program. When the integrated modeling approach was used, it was shown that the machining time can be decreased significantly along the tool path. Production time in machining propeller example was reduced to 35% compared to constant feedrate cases.


2011 ◽  
Vol 215 ◽  
pp. 176-181
Author(s):  
Li Min ◽  
Ke Hua Zhang

A new tool path generation method based on cutter shaft tilt method was proposed for free-form surface machining by using Ball-end Cutter. Firstly, it introduces the processing quality problems caused by traditional ball-end mill processing. Then cutter shaft tilt was proposed to avoid the above questions. Analyzing the different machining efficiency at the different angle, and then cutter shaft tilt compensation method which based on above method could avoid that problem was proposed. After the paths calculation to a real surface and simulation, the result shows that, comparing to traditional machining method, the new method reduced efficiently phenomenon of extruding and scratching surface. It meets five-axis processing accuracy requirements.


2011 ◽  
Vol 55-57 ◽  
pp. 1932-1937
Author(s):  
Li Song ◽  
Shu Kun Cao ◽  
Kai Feng Song ◽  
Chang Zhong Wu ◽  
Wei Wei Song

The paper presented the development of free-form surface axis NC machining tool path optimization module. In the UG environment, have three-dimensional solid modeling to the surface, and then have the secondary development of free-form surfaces five-axis machining path optimization module through the UG/Open API and VC++6.0. This can realize NC processing path automatically generation and optimization after the three-dimensional modeling. Introduction


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