转台角速率的高速摄像测量方法

High-speed video measurement method for rotary table angular rate

针对精确测量转台角速率在转台性能评价中的重要性问题,提出一种测量转台角速率的高速摄像方法.该方法利用平行光管作为可测目标固定在转台上,目标的空间位置与转台转动的角位置相对应,在转台转动过程中,通过高速相机记录目标空间位置实现测量,并采用像元细分技术定位的方法来提高测量精度,细分精度达到0.03个像元.利用该方法对某型号的低速转台进行了试验数据采集及分析,验证了该方法的可行性.误差分析结果表明,在转台角速率为0.2°/s时,该方法的测速精度可达到3.405×10-4,完全可以用于高精度转台的角速率测量.由于高速相机的采样频率较高,因此,实现了转台瞬时角速率的测量.该方法的非接触测量方式实现了对转台角速率的客观评价.

For the importance of measuring accurately the angular rate in the performance evaluation of rotary table,a high-speed video method for measuring the angular rate of rotary table was proposed.A collimator tube was fixed to the rotary table as a measureable objective,and the space position of the objective was corresponding to the rotating angular position of the table.In the rotating process of rotary table,the objective space position was recorded with a high-speed camera and thus the measurement was implemented.The orientation method with the pixel subdivision technology was adopted to improve the measurement precision,where the subdivision precision could reach 0.03 pixels.This method was used to collect and analyze the test data for a certain type of low-speed rotary table.The error analysis result shows that the precision of rate measurement can reach 3.405×10-4 when the angular rate of rotary table is 0.2°/s.It means that the present method can be used for measuring the angular rate of high-precision rotary table.The instantaneous angular rate of rotary table can be measured due to the high sampling frequency of high-speed camera.The objective evaluation for the angular rate of rotary table is realized with the non-contact measurement way in the proposed method.