基于视觉的柔性结构振动测量及其控制

Vision-Based Vibration Measurement and Control of Flexible Structure

针对柔性结构振动测试及控制问题,提出采用机器视觉测量结构振动并进行反馈控制的方法。为保证闭环控制系统的实时性,需要解决视觉图像处理数据量大、处理耗时长的问题。采取运动跟踪方法选择图像感兴趣区域(re-gion of interest,简称ROI)以减少数据处理量,并采用快速中值滤波算法提高图像处理速度。为了提高处理精度、保证处理结果的准确性,试验比较了3种微分边缘检测算子,采用Roberts算子和极值法提取图像中柔性结构末端边缘信息,并利用Hough直线变换方法进行修正。基于末端中心振动的信息反馈进行柔性梁结构振动控制理论分析和试验研究。结果表明,所采用的图像处理方法满足精度和实时性的要求,并验证了基于视觉反馈振动控制的可行性。

Aimed at the problem of vibration measurement and suppression of flexible structure,a vision-based vibration measurement and feedback control method of flexible structure is proposed.In order to ensure real time of the closed-loop system,it is necessary to solve the problem of excessive processing time needed for mass data computing.A motion-tracking method is used to determine region of interest(ROI) of single frame to reduce the amount of processed data.Also,a fast median filter method is used to improve the speed of image processing.Roberts operator can improve processing precision of the beam's tip edge detection,as compared with the other two differential detecting operators.Extremum and Hough transformation methods are used to extract and correct the edge information,respectively.Finally,theoretical analysis and experimental research of the vision-based vibration control are carried out.The results demonstrate that the adopted image processing methods meet the requirement of precision and real time,and also verify the feasibility of the vision-based vibration control scheme.