Flexible Cold Roll Forming The Control System Condition Monitoring

Flexible roll-forming is a new technology that produce sheet with changeable section. The sheet with proper designed section can increases the force capacity, reduce the structural weight and the cost. A flexible roll forming machine is developed by North China University of Technology, the state monitoring and control of this machine are the main objects of this study.When the servo-motor activate the roller, with changeable speed and location, sheet production with different section can be gotten. So the speed and location control of the roller is very important.Because the shape of the sheet section is closely related to the motor's speed and sheet speed, so the sheet speed is the important factor which can affect the roller. By choosing a rational speed sensor and rational filter design, the sheet speed is achieved with high precision. Another important state is the location of roller. By choosing the proper grating ruler and anti-noise approach, the location of the roller can be measured.The performance of the servo motor directly affect the velocity and location of the roller. So the research of the servo motor's characteristic curve is needed. The gap of the mechanical transmission system including both positive-negative gap and cumulative gap which made by roller screw is the important factor which affect the controlling precision. Though a large amount of experiment which measuring the gaps, the compensation can be obtained to improve the control precision.In addition, there are a lot of switching signals in the roll-forming process, such as the location of sheet and initialization signal of the roller, which must be monitored to affect the control precision.This issue use the software and hardware of the virtual instrument. At different sheet speeds, a lot of sheet with different section is rolled to analyze the factors which affect the production precision and offer experiences for the research in the future.