Study On Non-Orthogonal Coordinate On-Line Measuring System

On-line measurement is the technology which based on the Computer Number Control (CNC), and used measurement technology in manufacture process to decrease working accessorial time. It is necessary to measure pieces accurately and monitor tools wear in the process. This thesis studies the On-line non-orthogonal coordinate measurement system for measuring pieces and tools simultaneously with one time localization.The measurement system were built in this study according to the joint robot and technology of potable-joint coordinate measuring machines (PCMMS), and improved Unimation PUMA 560 robot to design four-joints on-line measurement arm. The main results are as follows: the author had been achieved the conceptual design of the four-joints measurement arm, and selected touch trigger probe to make up of probe system;We built the kinematics model for the measurement arm and gained kinematics equations by using homogeneous transformation matrix( D-H). Kinematics equations was tested by simulation of the measurement system which based on both graphic method and Matlab tool software ; Error analysis model was built for the end of the measurement arm, then simulated by Matlab tool software. The measurement accuracy can reach 0.006mm, and met the need of on-line measurement when the measurement arm uses more precise angle encoder. The motion simulation model which built by Pro/ENGINEER wildfire2.0 CAD software, proved each element moved normally without interference, then it is feasible for the four-joints measurement arm to apply to CNC.This study built the on-line non-orthogonal coordinate measurement system. It was convenient and not necessary to change probes for measuring different parts when this system used to measure the pieces and tools at the same time. And this system can reduce working accessorial period, increase efficiency and ensure precision of production.