应用于单目3D相机中MEMS镜的扫描角度补偿

Scanning Angle Compensation of MEMS Mirror Applied in Monocular 3D Camera

为了提高单目视觉相机的测量精度及测试数据的可重复性,提出了一种应用于激光扫描投影中扫描镜的闭环控制方式来提高投影出的条纹位置的稳定性。利用集成在扫描镜上的压阻传感器提供的反馈信号进行闭环控制,同时针对压阻传感器的温度特性,设计了测试系统来标定压阻输出与温度关系曲线。通过记录每一个温度下压阻的反馈输出值,生成反馈输出与温度的关系表。在室温至70℃的温度区间内,扫描镜的扫描角度的变化量由3.52°减小到0.05°。通过对扫描镜的扫描角度补偿控制后,单目视觉相机的三维测试精度以及测试数据的可重复性都得到了大幅提升。

In order to improve the measurement accuracy and repeatability of monocular vision camera,a closed-loop control method for the scanning mirror in laser scanning projection is proposed to improve the stability of the projected fringe position.The closed-loop control is carried out by using the feedback signal provided by the piezoresistive sensor integrated on the scanning mirror.At the same time,according to the temperature characteristic of piezoresistive sensor,a test system is designed to calibrate the relationship between piezoresistive output and temperature.By recording the piezoresistive feedback output value at different temperature,a table of the relationship between the feedback output and temperature is generated.In the temperature range from room temperature to 70℃,the scanning angle change of the scanning mirror decreases from 3.52°to 0.05°.By compensating the scanning angle of the scanning mirror,the 3D testing accuracy and the repeatability of the testing data of the monocular vision camera are greatly improved.