扫描式激光测振仪的姿态控制算法

Pose Control Algorithm of Scanning Laser Doppler Vibrometer

双轴振镜系统是扫描式激光多普勒测振仪中控制激光束运动的核心部件。通过双轴振镜系统中X,Y振镜的空间位置关系及光学反射原理,建立了激光束方向与X,Y振镜偏转角度之间的关系及其数学模型,并进一步基于多项式拟合算法实现了激光点从振镜系统坐标系到实测结构坐标系的坐标变换,从而可高精度控制扫描激光的姿态。同时,利用高清摄像头将测试坐标系转换到屏幕坐标系,提高了该方法的实际操作性。最后,以某型压气机叶片为例对该方法进行了验证,结果表明本方法对实现激光在实测结构表面任意测点的精确位置控制提供了理论基础,具有较好的指导作用。

The dual-axis galvanometer system isone of the key parts of the scanning laser Doppler vibrometer.According to the spatial position relation of the XY mirrors and the principle of optical reflection in the dual-axis galvanometer system,a mathematical model isestablished.Further,the coordinate transformation of the laser points’coordinate system from the galvanometer system to the actual structural coordinate system is carried out based on polynomial fitting algorithm.So the pose of laser can be controlled precisely.Meantime,to improve the practical operation,a high-definition camera is applied to transform the actual structural coordinate system to the screen coordinate system.Finally,the validation of the proposed algorithm is performed with a compressor blade.It demonstrated the ability and reliability of the proposed method and taken a guiding function for the precise position control of laser on arbitrary measuring points.