Research on Method of Parameter Identification and Error Compensation of Glass Substrate Transferring Robot

以提高玻璃基板搬运机器人的绝对定位精度为研究目标，在对机器人的定位误差来源进行详细分析的基础上，确定将机器人的零位参数、运动学参数和柔性参数的辨识和补偿作为提高机器人精度的主要途径。基于机器人参数辨识的研究现状，重点从零位参数辨识方法、柔性参数误差模型与运动学误差模型的耦合关系、柔性参数辨识方法、柔性变形对运动学参数辨识效果的影响以及机器人定位误差综合补偿等方面开展研究工作。首先，结合辨识法和几何法的优点提出了一种基于双轴倾角传感器的新零位标定方法，这种方法通过仪器的两次安装和对机器人的简便操作后即可完成整个零位标定。建立了新标定方法所涉及的参考零位和2 轴零位获取方法及3～6轴零位辨识方法两大关键问题的理论依据，并对辨识过程进行了仿真。对新标定方法的可行性进行了实验，证实了所提出的零位标定方法可大幅降低机器人的定位误差，具有节省成本、操作简便、辨识精确的技术特点。其次，建立了机器人运动学参数误差模型、关节柔性参数误差模型以及连杆柔性参数误差模型，并在此基础上结合DH 模型和连杆弹性梁模型推导出运动学参数与柔性参数的耦合误差模型，为进行柔性参数的辨识和柔性变形误差的补偿奠定了基础。分别基于圆点分析法和有限元分析法完成了机器人关节和连杆柔度参数的辨识。在圆点分析法的应用中，为避免刚体运动对圆点测量精度的影响，增加了转动中心处的测量点，使最终测量得到的末端测量点轨迹更接近于圆弧，从而提高了关节柔度辨识的准确性。对柔性变形的计算结果进行了实验，证实了模型和辨识结果的准确性。再次，利用最小二乘法建立了机器人运动学参数的辨识模型，并从提高辨识过程效率的角度出发，分别进行了参数辨识的灵敏度调整和测量位姿的选择优化。在此基础上，对机器人柔性变形对运动学参数辨识精度的影响进行了仿真分析，发现若不考虑柔性变形将造成参数辨识出现较大的偏差，为此提出基于柔性变形补偿的运动学参数辨识方法，并将其成功应用在SR210B 型机器人的运动学参数辨识实验中。最后，进行了机器人自身的运动学参数误差和柔性变形误差补偿实验，将机器人自身的定位精度提高到一个新的水平。针对玻璃基板在机器人手叉上的变形，提出了相应的变形调整方法，使机器人可满足玻璃基板的高速、高精度需求

Industrial Robot Joint Stiffness and Backlash Identification based on Circle- Point Analysis Method

提出基于圆点分析法进行机器人关节刚度和回差的辨识。建立了机器人的关节刚度及回差的耦合传动误差模型,给出了关节误差及关节重力矩的计算方法。以SRH6C机器人为对象进行了试验验证,验证了方法的可行性,从而为提高机器人的绝对定位精度提供了理论依据

Joint stiffness identification and flexibility compensation of articulated industrial robot

Articulated robots are the most common industrial robots for their large workspace and flexibility. However, the existence of joint flexibility makes those robots difficult to achieve high absolute position accuracy. This paper presents a method to identify the joint stiffness of the robot. The basic idea of that method is to get joint stiffness based on Hook's Law through stepping movement of a single joint and calculating the corresponding joint gravity torque of every step. The practicality of that method is verified by experiment and a plan is carried out to compensate the joint flexibility. © (2013) Trans Tech Publications, Switzerland

Analysis and Compensation For the Dynamic Error of The FPD Glass Substrates Transfer Robot

High-generation FPD (Flat Panel Display) glass substrates need to be carried by large clean transfer robot. Due to the space of the deposited glass box is limited, the distance between the two substrates is very small, this requires the sag amount of the robot fork must be controlled within a certain range. The traditional design is completed only in robot manufacturing stage by adding a shim to compensate for this distortion, but this method can only make the fork be compensated at a determined location, deformation at other locations may not be considered. A new solution to the dynamic compensation for the robot fork is proposed. By establishing the robot FEA model and mechanism accuracy model respectively, the synthetic dynamic error is then obtained. One can just change the mechanism accuracy through rational allocation of design tolerances of the robot links to minimize the dynamic error

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors