1 四川大学空天科学与工程学院，四川 成都 610065
2 中国工程物理研究院机械制造工艺研究所，四川 绵阳 621999
利用深度学习实现视觉图像的实时检测和姿态解算是引导机器人智能抓取的重要手段。针对机器人抓取检测中对准确性、实时性和稳定性的需求问题，构建了一种基于稳定轻量级网络的新型机器人抓取检测方法。将实例归一化层用于网络的卷积层和残差块中，每次只考虑单张图片的一个通道，不仅减少了运算量，还能有效利用单张图片的每个像素信息，在提升每个图像实例之间检测稳定性的同时加快模型收敛的速度；将特征金字塔网络分层结构融入上采样，并结合多维度语义信息增加对多尺度物体检测的准确度和稳定性。所构建的轻量级模型在交并比（IOU）为0.25时准确度为94.4%，画面传输速度为40.8 frame/s，并且在IOU低于0.5时准确度仍保持在80%以上。实验证明了在轻量级网络中加入实例归一化和特征金字塔的有效性。
机器视觉 机器人抓取 轻量级网络 物体检测 姿态检测 中国激光
2023, 50(13): 1304003
Author Affiliations
Abstract
1 State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China
2 Guangxi Key Laboratory of Precision Navigation Technology and Application, Guilin University of Electronic Technology, Guilin 541004, China
3 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
Nano-focusing structures based on hybrid plasmonic waveguides are likely to play a key role in strong nonlinear optical devices. Although the insertion loss is considerable, a significant nonlinear phase shift may be achieved by decreasing the nano-focusing device footprint and careful parameter optimization. Here, we study the Kerr effect in hybrid plasmonic waveguides by analyzing the mode effective area, energy velocity, and insertion loss. Particularly, by utilizing plasmonics to manipulate the effective index and mode similarity, the TM mode is reflected and absorbed, while the TE mode passes through with relatively low propagation loss. By providing a deep understanding of hybrid plasmonic waveguides for nonlinear applications, we indicate pathways for their future optimization.
silicon photonics plasmonics nonlinear optics nano-focusing Chinese Optics Letters
2022, 20(3): 031903
Author Affiliations
Abstract
1 State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871, China
2 Peking University Shenzhen Research Institute, Shenzhen 518057, China
3 Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, China
Optical microring resonators are extensively employed in a wide range of physical studies and applications due to the resonance enhancement property. Incorporating coupling control of a microring resonator is necessary in many scenarios, but modifications are essentially added to the resonator and impair the capability of optical enhancement. Here, we propose a flexible coupling structure based on adiabatic elimination that allows low-loss active coupling control without any modifications to the resonators. The self-coupling coefficient can be monotonically or non-monotonically controllable by the proposed coupler, potentially at a high speed. The characteristic of the coupler when implemented in silicon microring resonators is investigated in detail using substantiated analytical theory and experiments. This work provides a general method in coupling control while ensuring the resonance enhancement property, making active coupling control in a resonator-waveguide system feasible.
silicon photonics adiabatic elimination resonance system Chinese Optics Letters
2020, 18(1): 013601
中国工程物理研究院机械制造工艺研究所, 四川 绵阳 621000
抛光液黏度是影响射流抛光(FJP)效果的重要因素,针对硬脆光学元件射流抛光中对抛光液黏度缺乏系统研究的现状,研究了抛光液黏度变化对材料去除函数的影响。建立射流抛光连续相、离散相模型和磨损模型,计算不同黏度下磨粒运动轨迹,分析磨料颗粒撞击速度矢量随黏度的变化规律。配置不同黏度相同质量分数的抛光液,结合BK7工件静态采斑实验研究与塑性磨损理论计算,获得不同黏度下的材料去除函数,分析黏度对去除函数的影响机制,并进一步研究由此引起的工件表面粗糙度变化。结果表明:随着抛光液黏度增大,材料去除函数的去除深度减小、去除形状及去除范围保持不变,这有利于降低工件表面粗糙度。该研究扩展了现有光学元件射流抛光材料去除理论,对实际抛光液黏度调控具有理论指导意义。
光学加工 射流抛光 抛光液 黏度 材料去除 光学学报
2018, 38(12): 1222003
中国工程物理研究院机械制造工艺研究所, 四川 绵阳 621900
提出了一种高斯型去除(GTR)函数生成过程的数学建模方法。基于环路积分的思路,建立了一种旋转扫掠生成GTR函数的数学模型,明确了喷嘴高度为决定GTR函数形貌的关键工艺参数,验证了模型的正确性。在该模型的指导下,进一步研究了生成GTR函数的喷嘴高度范围和GTR函数的形貌变化规律,发现当回转中心与定点斜入射去除函数最深点重合时,生成的去除函数最接近理想高斯型。这对实际加工中工艺参数的优化具有理论指导意义。
光学设计 射流抛光 数学模型 高斯型去除函数 光学学报
2018, 38(10): 1022002
中国工程物理研究院机械制造工艺研究所, 四川 绵阳 621900
提出了一种快速生成高斯型去除函数的实验方法。通过研究倾斜定点入射方式下射流束中心与工件的交点和材料去除形貌之间的关系,得到了对应高斯型去除函数的喷嘴高度范围。在确定的工艺参数条件下,添加主轴旋转运动,得到了对应高斯型去除函数的喷嘴高度。对高斯型抛光斑进行了对称性分析和动态去除实验。结果表明,以高斯斑为基础的动态去除过程具有较高稳定性,能满足超精密光学加工的要求,同时也证明了该方法的高效性和可靠性。
光学制造 射流抛光 快速生成 实验方法 去除函数 高斯型
1 中国科学技术大学 精密机械与精密仪器系, 合肥 230026
2 中国科学院 国家天文台 南京天文光学技术研究所, 南京 210042
3 中国科学院 天文光学技术重点实验室, 南京 210042
根据多镜面地基望远镜在近红外实现共相衍射极限成像的需求，提出了一种基于压电堆栈致动器的高分辨率倾斜镜设计方案。该方案以哑铃型柔性铰链和菱形位移缩小结构(RADS)作为倾斜镜的运动传递元件，压电堆栈致动器(PSA)作为动力元件，并使用电涡流传感器作为角度测量部件。介绍了高分辨倾斜镜的工作原理，并对哑铃型柔性铰链和菱形位移缩小结构进行设计。柔性铰链和位移缩小结构的关键结构参数均采用理论计算、实验和仿真进行优化。建立倾斜镜模型，利用理论计算和有限元仿真软件分别计算倾斜镜的倾斜角度和分辨率。实验结果表明：设计的倾斜镜角度分辨率达到0.017″，最大倾斜角度为14.6″，谐振频率为136.97 Hz，与有限元仿真结果相吻合，满足地基望远镜系统衍射极限成像的要求。
倾斜镜 高分辨率 压电堆栈致动器 地基望远镜 柔性铰链 tip/tilt mirror high angular resolution piezoelectric stack actuator ground-based telescope flexible hinge 强激光与粒子束
2018, 30(7): 074102
Author Affiliations
Abstract
State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
The pose estimation method based on geometric constraints is studied. The coordinates of the five feature points in the camera coordinate system are calculated to obtain the pose of an object on the basis of the geometric constraints formed by the connective lines of the feature points and the coordinates of the feature points on the CCD image plane; during the solution process, the scaling and orthography projection model is used to approximate the perspective projection model. The initial values of the coordinates of the five feature points in the camera coordinate system are obtained to ensure the accuracy and convergence rate of the non-linear algorithm. In accordance with the perspective projection characteristics of the circular feature landmarks, we propose an approach that enables the iterative acquisition of accurate target poses through the correction of the perspective projection coordinates of the circular feature landmark centers. Experimental results show that the translation positioning accuracy reaches ±0.05 mm in the measurement range of 0–40 mm, and the rotation positioning accuracy reaches ±0.06o in the measurement range of 4o–60o.
物体位姿 几何约束 缩放正交投影 圆形特征标志 校正 150.0155 Machine vision optics 330.4060 Vision modeling Chinese Optics Letters
2011, 9(8): 081501
南开大学 光电子所,天津市光电子薄膜器件与技术重点实验室, 天津 300071
提出一套以大规模现场可编程门阵列(FPGA)-EP1C12Q240C8为控制核心,对静态存储器实行乒乓操作,实时处理解码后来自显卡数字视频接口(DVI)的信号及产生相应控制信号,以实现驱动薄膜晶体管(TFT)显示屏的实时动态图像显示的方案，并成功验证了该驱动方法的可行性。该系统对于驱动不同类型的TFT液晶或OLED显示屏,只需根据具体的屏编写相应的软件和增加少量的接口电路就可以实现,具有多用途、可复用的特点。关键词： 大规模现场可编程门阵列； 乒乓操作； 薄膜晶体管显示屏； 可复用
FPGA Ping-Pang operating Manner TFT-screen IP-Repeatability
