基于非接触摄影测量的拉索索力测试

开展了基于运动目标图像跟踪法的拉索索力测试研究.在拉索上布置目标测点,用摄像机获取单个及多个目标的振动图像序列,利用背景差分法进行运动目标检测,基于卡尔曼滤波法对运动目标进行跟踪,获得拉索多个目标测点的振动位移时程曲线,进而利用频率法求解拉索索力.实验结果表明,与加速度传感器的结果相比,摄影测量法测试结果可信,是基于频率的拉索索力测试方法的有效发展与补充.

Cable Force Identification Based on Non-contact Photogrammetry System

The development of the video camera with high speed and high resolution makes it possible to conduct photogrammetry-based non-contact displacement measurement. This paper presented the estimations of the tension force of a cable by using the moving target image tracking technologies. A video camera was employed to capture the vibration image sequences of single or multiple targets installed along the cable. The background difference method was used to detect the moving targets, and then, the Kalman filter was conducted to track the moving target, from which the vibration response of the cable can be attained to extract the cable force in the general frequency-based method. The experiment test results reveal that there is a small error between the results measured from photogrammetry and those from accelerometers. The photogrammetry method has the potential of becoming an effective complement of the non-contact testing.