Measurement System For CNC Vertical Lathe Workpiece Online Dynamic Balance

Rotating machinery is an important part in mechanical system, which has a great significance in defensive and civil domain. With the increasing application of rotary mechanism in industry production, the quantity of machine devices malfunctions and accidents due to unbalanced rotary is increasing quickly. Presently, dynamic balance of rotary machinery has become an indispensable working procedure in manufacturing.CNC Vertical Lathe, as a precision machining, has strict requirements in machining accuracy. The workpiece may not be necessarily clamped in the center of worktable. So, in the process of machined workpiece, when the worktable rotates, it will produce a certain centrifugal force, causing unbalance. This imbalance can cause the vibration of rotor system, greatly impacting the workpiece machining accuracy. The main objective of this task is to develop a detection system to test online unbalance of CNC Vertical Lathe workpiece during rotation.The paper combines dynamic balance measurement technology and digital signal processing technology, developing an online dynamic balance testing system based on DSP (Digital Signal Processing). The paper firstly expounds the basic theory of dynamic balancing, vibration measurement technology and signal processing, calculation of unbalance amplitude and phase based on DFT. Developing a dynamic balance testing system by utilizing DSP as the core chip while referring to dynamic balance testing system at home and abroad. Paper presents the overall system design, including selection of the master chip, speed reference signal acquisition and processing, vibration signal pre-processing and collection, designing of human-computer interaction (keyboard,LCD), etc; Given rotational speed reference signal processing circuit, vibration signal processing circuit, DSP main control unit circuit, power circuit, keyboard circuit and LCD circuit design, which main complete signals pretreatment, system operating and data display; Using modular design method, including dynamic balance analysis module, measurement of rotational speed module, time-domain waveform analysis module, frequency-domain waveform analysis module, communication module between DSP and PC.The system can measure, calculate and demonstrate vibrating signals in real time and realize data communication with PC through RS232. The system can meets the test requirements that measurement accuracy, easy operation, fast speed and high precision.