Measuring Software Test Verification for Complex Workpieces based on Virtual Gear Measuring Instrument

Validity and correctness test verification of the measuring software has been a thorny issue hindering the development of Gear Measuring Instrument (GMI). The main reason is that the software itself is difficult to separate from the rest of the measurement system for independent evaluation. This paper presents a Virtual Gear Measuring Instrument (VGMI) to independently validate the measuring software. The triangular patch model with accurately controlled precision was taken as the virtual workpiece and a universal collision detection model was established. The whole process simulation of workpiece measurement is implemented by VGMI replacing GMI and the measuring software is tested in the proposed virtual environment. Taking involute profile measurement procedure as an example, the validity of the software is evaluated based on the simulation results; meanwhile, experiments using the same measuring software are carried out on the involute master in a GMI. The experiment results indicate a consistency of tooth profile deviation and calibration results, thus verifying the accuracy of gear measuring system which includes the measurement procedures. It is shown that the VGMI presented can be applied in the validation of measuring software, providing a new ideal platform for testing of complex workpiece-measuring software without calibrated artifacts.

Research on Finite Element Simulation Processing Method for Flatness Prediction

The prediction of flatness is researched based on the simulation of virtual NC manufacture process. In this paper, a new interpolation-regression model is proposed, which is based on the simulation method of the finite element analysis and depends on MATLAB to realize the calculated algorithm of flatness error. In the model, on the premise of that the workpiece is completed the simulation, the information of numerous discrete points is acquired from the virtual workpiece. A new surface which is much closer to the workpiece morphology is generated by interpolation theory with statistics toolbox of MATLAB. The assessed datum of flatness is concluded by the theory of the multivariate linear regression. Synthesizing the original points and the created datum, the work calculates the flatness error and develops the flatness predicted system of virtual workpiece. The system can realize the vivid man-computer interaction in MATLAB.

Virtual Workpiece Modeling for the Virtual Gear Measuring Center

The architecture of VGMC was introduced, a virtual workpiece modeling methods and procedures was proposed, also the workpiece drawing in professional graphics software was transformed successfully into VGMC. It proves that the virtual wokpiece can be used in the virtual measurement, and the measurement software will be detected by virtual measurement using virtual wokpiece.

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.

Creating Freeform Model by Carving Virtual Workpiece With Haptic Interface

This paper presents the development of a virtual sculpting system, with the goal of enabling the user to create a freeform model by carving a virtual workpiece with a virtual tool while providing haptic interface during the sculpting process. A virtual reality approach is taken to provide stereoscopic viewing and force feedback, thus making the process of model creation in the virtual environment easier and more intuitive. The development of this system involves integrating techniques and algorithms in geometric modeling, computer graphics, and haptic rendering. Multithreading is used in an attempt to address the different update rates required in the graphic and haptic displays.

Virtual Reality Environment for Creation of Freeform Models

A novel method has been developed using a virtual reality (VR) environment to create solid models with freeform surfaces. The VR environment emulates the physical environment for creating freeform objects, i.e. the freeform model is created in a virtual environment by shaping a virtual workpiece with a variety of virtual tools. The trajectories of the virtual tools are generated by the designer’s hand movements and they are obtained by recording the position and orientation of the motion tracker mounted on a device held by the hand. In the mathematical algorithm, the swept volumes of the design tools are computed from the tools’ geometric data and trajectories. Boolean operations are then performed on the swept volumes of the virtual tools and the virtual workpiece to create the design model.