high speed video and images

The device fabricated using the parameter values obtained from the parametric analysis is tested for its performance by applying an impulse load through a spring manipulator, and the device response is captured using a PHOTRON high speed camera. When the manipulator is pulled down and released, the stage impacts a stationary wall causing a shock impulse, the magnitude of the impact can be controlled by the length through which the manipulator is pulled back. The acceleration impulse data is recorded using a Polytec point measurement vibrometer, by pointing the laser beam on the tip of the spring manipulator. To start the camera and the vibrometer at the same time, a 5V TTL pulse signal is fed to the vibrometer from the camera that triggers the vibrometer on starting the high speed camera. Now, we have frame sync between the camera and the vibrometer, which marks the zero time of reference. The camera captures 20,000 frames per second, which is good enough to capture the impact event and the dynamics of the device. The response data from the high speed camera is then processed using the image processing toolbox in MATLAB to get the experimental device response. The acceleration profile recorded by the laser vibrometer is used in the simulation of the device response using the analytical method . The impulse data recorded by the vibrometer is given as the acceleration profile that is used in obtaining the analytical solution.

基于参数化分析得到的参数值加工制备的实验装置，通过弹簧操纵器施加脉冲载荷以开展性能测试，并借助PHOTRON高速相机（high speed camera）采集装置响应信号。当操纵器被下拉后释放时，载物台会撞击固定墙面并产生冲击脉冲，冲击幅值可通过操纵器向后拉动的行程进行调节。将激光束对准弹簧操纵器的尖端，利用Polytec点式测振仪（point measurement vibrometer）记录加速度脉冲数据。为实现高速相机与测振仪的同步启动，由相机向测振仪输入5V TTL脉冲信号（5V TTL pulse signal），使测振仪随高速相机一同触发开机，此时相机与测振仪间建立帧同步关系，以此作为参考零时刻。该相机的拍摄帧率为20000帧/秒，足以完整捕捉冲击过程与装置的动力学演化过程。随后借助MATLAB图像处理工具箱对高速相机采集的响应数据进行后处理，以获取实验装置的响应结果。将激光测振仪记录的加速度波形作为输入载荷，通过解析方法开展装置响应仿真；测振仪采集的脉冲数据以加速度波形形式提供，用于求解解析解。