Jing Chuan Dong

NC Machining Simulation of Spiral Bevel Gear Based on VERICUT

Based on the traditional cradle-type spiral bevel gear machining theory, the mathematical model of tilt machining method for the pinion member of spiral bevel gear pair is created. Then, by applying coordinate transformation method from crade-type machine to CNC one, a five-axis virtual CNC machine model is established by VERICUT software. at the same time, the pinion cutting simulation is carried out under VERICUT according the properties of the general five-axis CNC system and the relevant configuration parameters. By using this method, the accuracy of the bevel gear cutting system based on a general five-axis CNC can be well verified.

The Investigation of the Effect Caused by Deposition Velocity on Bonding Degree within the Structure of FDM

In this paper, the effect of deposition velocity on bonding degree is studied in the aspects of experiment and theory. The experimental results show that the bonding quality of the adjacent filaments is weakened with increasing of deposition velocity. In addition, on the premise of guaranteeing every point in the building process to remain at the optimal temperature, the quantitative relationships between interval and filled area, deposition velocity are investigated by using the technique of deactivate and reactivate element of finite element. On the base of the quantitative relationships, the variable deposition velocity printing method is proposed for the first time. Namely, to reap the best bonding quality of filaments the time of completing one layer can be determined according to the filled area, and then, the optimal deposition velocity can be obtained according to the quantitative relationship between the interval and the deposition velocity. Printing the model at this speed can obtain the part with the best bonding quality between adjacent layers.

The Digital Manufacturing Equipment and Development of High Speed and High Precision with Monitoring and Intelligent Maintenance

With the development of science technology in aerospace, automobile and ship, energy and military, the product parts space type face increasingly complex and surface quality requirements more stringent. So there are higher requirements to the digital manufacturing equipment to realize high speed and high precision machining. This paper summary the related research in condition monitoring, remote control, fault diagnosis and intelligent maintenance, and based on the lack of monitoring and diagnosis technology of whole life cycle, unperfected quality control technique, the lower intelligent level in the current equipment, it establish full range monitoring and the whole life cycle of the intelligent maintenance system and present fault diagnosis, control and maintenance solutions for the whole life cycle, and point out the new development direction of the integrated monitoring and intelligent maintenance in CNC equipment.

A Method of Pitch Error Compensation for the Open Numerical Control System

The traditional fixed pitch error compensation method exists some defects, such as sampling points are not comprehensive and the necessary compensation points are easy to miss. Faced with these problems, this paper presented a new pitch error compensation method based on the open numerical control system. With this method, the traditional measurement points were serried, and more pitch error data were measured. Then calculated the error data with the cubic spline interpolation computation method, and the compensation location and value were obtained according to the accuracy requirement. The pitch error compensation was completed when the data inputted into the open numerical control system with a defined format.

The Study of S-Shaped Acceleration and Deceleration Curve and the Trajectory Planning Strategy Analysis

The invention of the Numerical Control (NC) technology have brought the new revolution of manufacturing since 20th century intermediate stage. Computer Numerical Control (CNC ) technology is the foundation of the modern manufacturing technology, integrating the traditional manufacturing technology, modern control technology and modern optical-electromechanical technology.[1,2]As the core of CNC technology, CNC system is requesting higher precision and higher speed as it develops. So it is necessary to meet the requirements of the machining surface quality and avoid the occurrences of the processing speed decline or even stall, which depends on the good controls of the acceleration and deceleration of the feed shaft [3].This article briefly analyzes some existing strategies of the acceleration and deceleration, then mainly introduces the s-shaped acceleration and deceleration curve method and the trajectory planning strategy of it.

Simulation Study of Motion Control for X-Y Table with a Novel Direct Contour Controller

Contouring accuracy is important in multi-axis computerized numerical control (CNC) machining. This paper proposed a direct contouring control (DCC) strategy for CNC contouring applications. The DCC implements velocity control in the tangential direction and position control in the normal direction, which is different from conventional axis-based position control schemes. The real-time contouring state monitoring method is introduced to obtain the necessary information for DCC. The motion profile is defined as a velocity-displacement function along the tool path. A new velocity interpolator is proposed to generate the tangential velocity command for DCC. A simulation experiment based on X-Y table model with circular trajectory is conducted to test the performance of the proposed method. The results show that the DCC can achieve high contour accuracy with a simple structure.

Study of Trigonometric Function Improved Acceleration-Deceleration Algorithm and Velocity Look-Ahead Control

The final process of workpiece is composed of a series of connected trajectories, and the expectation speed of the different trajectories may be different, so it requires the changes of acceleration and deceleration speed. This paper introduces the improved acceleration-deceleration algorithm of trigonometric function, and presents an optimization algorithm according to the changing trend of velocity to the method of forward-looking processing speed.

Adaptive Error Control Algorithm for High Speed Two-Axis CNC Contouring

The computerized numerical control (CNC) machining program usually contains a large number of small line segments. The CNC controller must generate a smooth and optimized motion profile to achieve high speed and high precision machining. This paper proposed an adaptive contour error control algorithm. The curvature radius of the tool path is obtained by analyzing the geometry relationship. The algorithm uses the curvature information and a simplified servo error model to realize contour error estimation and adaptive control. The target feet rate filter (TFF) and planning unit merging (PUM) are introduced to obtain a smooth profile. Experiments result demonstrated the efficiency of the proposed algorithm.

Research of the PLC Module Based on the Embedded NC System

PLC module is an important part of embedded NC system, and mainly accomplishes the auxiliary functions of CNC machine tools. This paper completes the work of research and development of the PLC programming software for PC side of the host computer, and the software is developed in VC++6.0 environment based on windows XP system, to realize the editing functions and the mutual conversion between the ladder and instruction language. Focus on the realization of the mutual conversion between ladder with instruction table, use the logical structure of tree when the ladder converts to the instruction table, and use the data structure of stack to complete the conversion. Instruction table is transformed to Ladder by the operation of the stack to complete the conversion.

Research on Algorithm of Trajectory Connecting with Straight Line in Motion Control of CNC

In view of the current trajectories connecting with straight line, the methods of transfer and error analysis are elaborated in detail. To the errors caused by current trajectories connecting with straight line, analysis of the relationship between transfer error and interpolation surplus coupled with the angle is explained. And the explanation is according to the different angles between velocity vectors.