Jian Guang Li

Cutting Parameters Optimization by Using Particle Swarm Optimization (PSO)

Cutting parameters play an essential role in the economics of machining. In this paper, particle swarm optimization (PSO), a novel optimization algorithm for cutting parameters optimization (CPO), was discussed comprehensively. First, the fundamental principle of PSO was introduced; then, the algorithm for PSO application in cutting parameters optimization was developed; thirdly, cutting experiments without and with optimized cutting parameters were conducted to demonstrate the effectiveness of optimization, respectively. The results show that the machining process was improved obviously.

Cutting Parameters Optimization for Constant Cutting Force in Milling

Due to cutting parameters playing an important role in machining economics and machining qualities, much attention has been paid to select optimum cutting parameters. In this paper, cutting parameters optimization for constant cutting force was discussed based-on virtual machining comprehensively. Particle swarm optimization (PSO) was used to seek for the optimal spindle speed and feed rate. The framework of virtual machining based cutting parameters optimization was established. Then two controlled experiments were conducted to demonstrate the effectiveness of cutting parameters optimization both with physical cutting and computer simulation. The results of experiments show that machining process with constant cutting force can be achieved via cutting parameters optimization based on virtual machining.

Virtual Assembly System for Large-Scale Complex Products

Due to complex process and high difficult operation for large-scale products assembly, the application of virtual assembly (VA) has an important significance and also an actual value. In this paper the key techniques of VA for large-scale complex products are proposed, and their assembly characteristics (such as their organization form, human participation, process planning and optimization and so on) are analyzed. First, a new virtual environment (VE) system considering human activities is set up. Second, an integration approach is realized to transform data from CAD to VA system, and a hybrid method on the basis of virtual reality (VR) and intelligent algorithm is applied to optimize and evaluate assembly process planning. Moreover, assembly documents generation and Web training for assembly workers are implemented. Finally, an application case of the VA system for a complex product is given, and further work is pointed out.

A Methodology of Off-Line Optimization for NC Milling Process

Traditional adaptive control technologies in machining process optimization are limited in applications because they depend much on sensors, controllers and other hardware. An off-line optimization method for end milling process with constant cutting power is presented. On taking advantage of virtual machining which simulates milling process, acquires cutting parameters and predicts cutting forces, method taking constant cutting power as an objective is discussed to optimize feed rates and cutting speeds. Based on optimal result, the feed rates and spindle revolutions in NC program are re-scheduled. Controlled milling experiments show that machining time is reduced and machining stability is improved by using the optimized NC program.

Dynamic Collision Detection with Optimum Discrete Interval

An improved algorithm, dynamic collision detection with optimum discrete interval is presented to improve the efficiency of dynamic collision detection. The algorithm based on the minimum distance between two objects with relative movement to determine the next discrete position, on which collision or interference is free. The method using the minimum distance as discrete interval to determine the next interference-free position makes each interval longest under the constraint of safety so that the reliability between the moving object-pair is ensured while the efficiency is improved. The practical demonstration has proved that the improved algorithm is capable of high performance than that of the collision detection method with even discrete interval. This algorithm has been successfully used in a verification system of inspection process by secondary development of Pro/Engineer.

VSPDT: An Optimizer for Single Point Diamond Turning

Virtual manufacturing (VM), which primarily aimed at reducing the lead times to market and costs associated with new product development, offers various test-beds for the time-consuming and expensive physical experimentation. Since surface roughness and form accuracy play essential roles in the functional performance of the products machined with ultra-precision machining technology. An optimizer, VSPDT (virtual single point diamond turning) system was developed for the purpose of form error compensation and optimal cutting parameters selection. In this paper, the keys issues for developing VSPDT using virtual manufacturing technology were highlighted such as framework of system, virtual workpiece, virtual machining and inspection, etc. At the end of the paper, A VSPDT was developed and applied to predict and compensate the form error, select optimal cutting parameters by using a 2-axis CNC ultra-precision turning machine.

Research on Software Error Compensation of Ultra-Precision Lathe

Based on the theory of kinematics for multi-body system, the relative motion constraint equation is deduced according to the structure layout and the error distribution of the ultra-precision lathe Nanoform200. By solving the constraint equation, the corrective NC code is derived that can compensate the geometric errors. The error compensation software is developed aimed at the ultra precision manufacturing of optics parts. The cutting experiments show that the method and model in this paper can improve the accuracy about 50% for the ultra-precision turning of optical parts.

Research on CNC Grinding Program of Overall End Milling Cutter

With high precision special rotary tool is widely used in automotive, mold, aerospace, machinery, electronics and other fields, the demand of manufacturing for such type and quantity of cutting tool is more and more big, lead to the demand for multi-axis CNC tool grinder which provides efficient, high quality production support for it also increasing. In terms of hardware and software multi-axis CNC tool grinder in developed countries are relatively mature, but domestic did not have enough for this research, especially for development of CNC tool grinding machine operation software system, and rarely reference data. In view of the domestic manufacturer in urgent need of independent research and development of CNC tool grinder, this article will research tool grinding automatic programming and simulation technology of CNC tool grinding machine operation software system, through analyzing the four main steps of NC grinding four-blade overall end milling cutter, parametric programming with MATLAB, and grinding trajectory data in the form of mixed programming of MATLAB and VC+ + will be post processed into NC programs, then simulation in VERICUT virtual machine tool, finally the actual grinding out overall end milling cutter.

Development Research of the End Mills Grinding Programming System Based on MATLAB

Using MATLAB for development tools,we has developed a set of end mills CNC grinding programming system by analysis the end mills grinding craft ,research on cutter location trajectory calculation and post-processing technology. Meanwhile, build a five-axis tool grinder grinding simulation processing by VERICUT(a kind of CNC machining simulation software), through the edge grinding simulation , we confirm the cutter location trajectory and the NC code is errorless.

Numerical Study of Improving Aerodynamic Performance of the Cylinder Airfoil of Magnus Wind Turbine

To solve the problem of low lift to drag ratio of Magnus cylinder airfoil, the Computational Fluid Dynamics software Fluent was used to study the principle of a drop of the drag force of cylinder when rotating. And the principle was used to further reduce the drag of rotating cylinder. A traditional airfoil head and a triangle tail was used to study the effect of the aerodynamic performance change of the combined airfoil. A conclusion was made that with a suitable profile of the tail would reduce the drag force of the combined airfoil thus increase the lift to drag ratio of the airfoil. At last an orthogonal test was made to determine the size of the tail airfoil. The result show that the optimized airfoil reduce the drag force to 50% of the original cylinder and improve the lift to drag ratio to 50%.