红外与激光工程, 2015, 44 (3): 0901, 网络出版: 2016-01-26
物理诊断设备精确自动准直方法
Automatic alignment method for diagnostic instrument
摘要
为了获取准确的激光打靶实验数据,需要使用诊断搭载平台搭载物理诊断设备对打靶目标进行高精度准直。针对传统方法存在耗时、误差(RMS)较大的问题,根据搭载平台与物理诊断设备的特点,提出了一种基于视觉伺服的精确自动准直方法。首先,构建三维准直向量估算立体视觉系统中靶的偏差,在弱透视条件下,估算值接近于真值;然后,建立三自由度姿态调节模型,提高姿态调节精度。最后,运用准直向量与调节模型设计视觉伺服控制器,仅需一次离线标定即可进行快速准直。通过以上改进,实现了物理诊断设备的精确自动准直。实验结果表明,诊断设备的准直精度(RMS)分别为:x指向为11 μm,y指向为12 μm。搭载分幅相机进行激光打靶考核验证,得到了物理实验过程的X光焦斑图像,表明准直方法满足工程使用要求。
Abstract
In order to capture accurate data of laser-driven fusion test, diagnostic instruments(DI) which are mounted onto diagnostic instrument manipulator(DIM) should align the target with tight tolerance. Traditional alignment methods have problems of time consumption and error large. An accurate automatic alignment method was introduced, which based on visual servoing according to the virtue of DIM and DI. First, a 3D alignment vector was constructed to estimate the target deviation in the stereo vision system. Under narrow field of view, estimated value was close to true deviation. Second, a 3 DOF pose adjusting mode was founded to promote motion accuracy. Finally, a visual servo controller based on the alignment vector and pose adjustment mode was designed. The process of alignment needs offline calibration only once. Through the three steps, DI can automatic align the target with high accuracy. Test indicates that alignment accuracy(RMS) is 11 μm in x direction and 12 μm in y direction. Laser shot test with X-ray framing camera show that the automatic align method can satisfy the project requirements.
王维, 何俊华, 张敏, 韦明志, 闫亚东, 杨正华, 杨品. 物理诊断设备精确自动准直方法[J]. 红外与激光工程, 2015, 44(3): 0901. Wang Wei, He Junhua, Zhang Min, Wei Mingzhi, Yan Yadong, Yang Zhenghua, Yang Pin. Automatic alignment method for diagnostic instrument[J]. Infrared and Laser Engineering, 2015, 44(3): 0901.