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| 1 | Dynamic Feedforward Control of a Novel 3-PSP 3-DOF Parallel Manipulator显示文摘Parallel manipulators with less than six degrees of freedom (DOF) have been increasingly used in high-speed hybrid machine tools. The structural features of parallel manipulators are dynamic, a characteristic that is particularly significant when these manipulators are used in high-speed machine tools. However, normal kinematic control method cannot satisfy the requirements of the control system. Many researchers use model-based dynamic control methods, such as the dynamic feedforward control method. However, these methods are rarely used in hybrid machine tools because of the complex dynamic model of the parallel manipulator. In order to study the dynamic control method of parallel manipulators, the dynamic feedforward control method is used in the dynamic control system of a 3-PSP (prismatic-spherical-prismatic) 3-DOF spatial parallel manipulator used as a spindle head in a high-speed hybrid machine tool. Using kinematic analysis as basis and the Newton-Euler method, we derive the dynamic model of the parallel manipulator. Furthermore, a model-based dynamic feedforward control system consisting of both kinematic control and dynamic control subsystems is established. The dynamic control subsystem consists of two modules. One is used to eliminate the influence of the dynamic characteristics of high-speed movement, and the other is used to eliminate the dynamic disturbances in the milling process. Finally, the simulation model of the dynamic feedforward control system of the 3-PSP parallel manipulator is constructed in Matlab/Simulink. The simulations of the control system eliminating the influence of the dynamic characteristics and dynamic disturbances are conducted. A comparative study between the simulations and the normal kinematic control method is also presented.The simulations prove that the dynamic feedforward control method effectively eliminates the influence of the dynamic disturbances and dynamic characteristics of the parallel manipulator on high-speed machine tools, and significantly improves the trajectory accuracy. This is the first attempt to introduce the dynamic feedfordward control method into the 3-PSP spatial parallel manipulator whose dynamic model is complex and provides a study basis for the real-time dynamic control of the high-speed hybrid machine tools. | HAO Qi GUAN Liwen WANG Jinsong WANG Liping | 2011 | Chinese Journal of Mechanical Engineering2011，24，4： | 10 |
| 2 | Step kinematic calibration of a 3-DOF planar parallel kinematic machine tool显示文摘This paper presents a novel step kinematic calibration method for a 3 degree-of-freedom(DOF) planar parallel kinematic machine tool,based on the minimal linear combinations(MLCs) of error parameters.The method using mapping of linear combinations of parameters in error transfer multi-parameters coupling system changes the modeling,identification and error compensation of geometric parameters in the general kinematic calibration into those of linear combinations of parameters.By using the four theorems of the MLCs,the sets of the MLCs that are respectively related to the relative precision and absolute precision are determined.All simple and feasible measurement methods in practice are given,and identification analysis of the set of the MLCs for each measurement is carried out.According to the identification analysis results,a step calibration including step measurement,step identification and step error compensation is determined by taking into account both measurement costs and observability.The experiment shows that the proposed method has the following merits:(1) the parameter errors that cannot influence precision are completely avoided;(2) it reflects the mapping of linear combinations of parameters more accurately and enhances the precision of identification;and(3) the method is robust,efficient and effective,so that the errors in position and orientation are kept at the same order of the measurement noise.Due to these merits,the present method is attractive for the 3-DOF planar parallel kinematic machine tool and can be also applied to other parallel kinematic machine tools with weakly nonlinear kinematics. | CHANG Peng,WANG JinSong,LI TieMin,LIU XinJun & GUAN LiWen Department of Precision Instruments and Mechanology,Tsinghua University,Beijing 100084,China | 2008 | Science China(Technological Sciences)2008，51，12： | 9 |
| 3 | Dynamic Manipulability and Optimization of a Two DOF Parallel Mechanism显示文摘The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspace of the manipulator, and can’t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom (DOF) parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part’s pivot point are derived from the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator. | SHAO Hua WANG Jinsong WANG Liping GUAN Liwen | 2010 | Chinese Journal of Mechanical Engineering2010，23，4： | 5 |
| 4 | Elliptical model for surface topography prediction in five-axis flank milling显示文摘In five-axis flank milling operations,the intersecting surfaces of different cutting edges create roughness on the milled surfaces that cannot be ignored in situations with strict requirements,especially in aeronautical manufacturing.To focus on motion problems in milling operations,this paper presents a new model that utilizes elliptical paths as cutting edge trajectories on 3D surface topography machined by peripheral milling.First,the cutter parallel axis offset and location angle are considered,which change the location of the ellipse center and intersection point of the cutting edges.Then,through the proposed model,the predicted surface topography is obtained,and the factors that affect the development tendency of roughness are analyzed.Next,the effects of the cutter location position(CLP)geometric parameters,cutter parallel axis offset and curvature on the roughness are evaluated by a numerical simulation.Finally,machining tests are carried out to validate the model predictions,and the results show that the surface topography predictions correspond well with the experimental results. | Liping WANG Shuyi GE Hao SIa Liwen GUAN Feiyu DUAN Yuzhe LIU | 2020 | Chinese Journal of Aeronautics2020，33，4： | 3 |
| 5 | Combined method for parallel manipulator configuration design显示文摘Configuration design is an essential, creative and decision-making step in parallel manipulator design process, in which modeling and assembly are iterative and trivial. Combined approach with automatic parametric modeling and automatic assembly is proposed for parallel manipulator configuration design. The design process and key techniques, such as configuration design, configuration verification, poses calculation of all parts in parallel manipulator, virtual assembly and etc., are discussed and demonstrated by an example. A software package is developed for parallel manipulator configuration design based on the proposed method with Visual C+ + and UG/OPEN on Unigraphics. | Guan Liwen(关立文) Wang Jinsong Wang Liping | 2005 | High Technology Letters2005，11，3： | 2 |
| 6 | A novel SIRT6 activator ameliorates neuroinflammation and ischemic brain injury via EZH2/FOXC1 axis显示文摘Ischemic stroke is the second leading cause of death worldwide with limited medications and neuroinflammation was recognized as a critical player in the progression of stroke,but how to control the overactive neuroinflammation is still a long-standing challenge.Here,we designed a novel SIRT6 activator MDL-811 which remarkably inhibited inflammatory response in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and primary mouse microglia,which were abolished by silencing SIRT6.RNA-seq screening identified the forkhead box C1 (Foxc1) is a key gene evoked by MDL-811stimulation and is required for the anti-inflammatory effects of MDL-811.We found MDL-811-activated SIRT6 directly interacted with enhancer of zeste homolog 2 (EZH2) and promoted deacetylation of EZH2 which could bind to the promoter of Foxc1 and upregulate its expression to modulate inflammation.Moreover,our data demonstrated that MDL-811 not only ameliorated sickness behaviors in neuroinflammatory mice induced by LPS,but also markedly reduced the brain injury in ischemic stroke mice in addition to promoting long-term functional recovery.Importantly,MDL-811 also exhibited strong anti-inflammatory effects in human monocytes isolated from ischemic stroke patients,underlying an interesting translational perspective.Taken together,MDL-811 could be an alternative therapeutic candidate for ischemic stroke and other brain disorders associated with neuroinflammation. | Tailin He Jialin Shang Chenglong Gao Xin Guan Yingyi Chen Liwen Zhu Luyong Zhang Cunjin Zhang Jian Zhang Tao Pang | 2021 | Acta Pharmaceutica Sinica B2021，11，3： | 1 |
| 7 | A study on the effect of structure parameters on the dynamic characteristics of a PRRRP parallel manipulator显示文摘 | Wu Jun Wang Liping Guan Liwen | 2013 | Nonlinear Dyn2013，，74： | 1 |
| 8 | Structure variations of TBA G-quadruplex induced by 2+-O-methyl nucleotide in K+ and Ca2+ environments显示文摘凝血酵素有约束力的 aptamer (TBA ) , d (GGTTGGTGTGGTTGG ) 的 15-mer oligonucleotide 顺序,褶层进一种椅子类型反平行在二 G 四个的 K + 环境,和各个 G 四倍被 synantisynanti glycosidic 描绘符合构造安排。探索它的合拢的拓扑学和结构的稳定性,有 C3-endo 糖的 2-O-methyl 核苷酸( OMe )皱起符合构造和反 glycosidic 角度被用来有选择地代替 TBA 的G四个的 guanine 残余,并且这些代替的 TBA 用一个圆形的二色性系列被描绘,热地微分的光谱,在 K +和 Ca 2+环境的紫外稳定性分析,电气泳动活动性移动试金,和热力学的分析。结果证明为 syn-dG 残余的单个替换使动摇 G 四倍的结构,当为 anti-dG 残余的单个替换能保存时在 K + 环境 G 四倍。当一或二 G 四个与 OMe 被修改时, TBA 变得未组织。在 Ca 2+ 环境,相反,本国的 TBA 看起来未组织。当二 G 四个与 OMe 被代替时, TBA 似乎成为更稳定的平行 G-4 结构。进一步热力学的数据建议 OMe 替换是一个热含量驱动的事件。在这研究的结果在不同离子的环境在 G 四倍的结构稳定性上关于核苷酸衍生物的效果充实我们的理解,它将帮助到为生物、医药的应用 G 四倍的设计。 | Xiaoyang Zhao Bo Liu Jing Yan Ying Yuan Liwen An Yifu Guan | 2014 | Acta Biochimica et Biophysica Sinica2014，46，10： | 0 |
| 9 | Erratum to: Fluorescent glycan nanoparticle-based FACS assays for the identification of genuine drug-resistant cancer cells with differentiation potential显示文摘Erratum to Nano Research 2020,13(11):3110-3122 https://d0i.0rg/l 0.1007/s 12274-020-2981-8 The article Fluorescent glycan nanoparticle-based FACS assays for the identification of genuine drug-resistant cancer cells with differentiation potential,written by Chenglong Wang et al.,was erroneously originally published electronically on the publishers internet portal(currently SpringerLink)on 10 August 2020 with the Acknowledgements. | Chenglong Wang Wencai Guan Rong Chen Yael Levi-Kalisman Yichun Xu Liwen Zhang Min Zhou Guoxiong Xu Hongjing Dou | 2021 | Nano Research2021，14，11： | 0 |
| 10 | AN EXPLOITATION OF THE EXPERT SYSTEM OF MECHANICAL DESIGN BASED ON VIRTUAL REALITY显示文摘0INTRODUCTIONInordertodesignamechanicalproductschemeinmoderntimes,youhavetowidenyourviewontheworld,analyzecomplexobject,study... | Wu Qunbo Wang Zhixing Li Chengyu Guan Liwen Dept of Mechanical Engineering, Harbin Institute of Technology | 1999 | Chinese Journal of Mechanical Engineering1999，12，2： | 0 |
| 11 | Synchronization control for electro-hydraulic dual-cylinder system based on force/position switching显示文摘If the rigidity of a mechanism is stiff enough,the position synchronous error of the two cylinders driving one degree-of-freedom(DOF)of the mechanism may be less than the resolution of position sensors.To handle this synchronization problem this paper proposes a force/position switching scheme,which partitions the two cylinders into a master cylinder and a slave cylinder.The master cylinder is always position tracking controlled by a second-order sliding mode controller and the slave cylinder is integrated with a force tracking controller which is a first order sliding mode controller.When the position tracking error is less than a given value,the slave cylinder switches to be force controlled.Two synchronization control methods are presented based on the switching scheme:the master-master+force/position switching control and the master-slave+force/position switching control.Simulations show that the proposed synchronization control methods can get a better performance compared with two given position-based control methods. | 程宁波 Wang Liping Guan Liwen Han Jian | 2013 | High Technology Letters2013，19，3： | 0 |
| 12 | Fluorescent glycan nanoparticle-based FACS assays for the identification of genuine drug-resistant cancer cells with differentiation potential显示文摘Herein we develop a unique differentiated-uptake strategy capable of efficient and high-purity isolation of genuine drug-resistant(DR)cells from three types of drug-surviving cancer cells,which include paclitaxel-surviving human ovarian OVCAR-3 cancer cells and human lung carcinoma A549/Taxol cells,and doxorubicin-surviving human immortalized myelogenous leukemia K562/ADR cells.By using this strategy which relies on fluorescent glycan nanoparticle(FGNP)-based fluorescence-activated cell sorting(FACS)assays,two subpopulations with distinct fluorescences existing in drug-surviving OVCAR-3 cells were separated,and we found that the lower fluorescence(LF)subpopulation consisted of DR cells,while the higher fluorescence(HF)subpopulation was comprised of non-DR cells.Besides,the DR cells and their progenies were found distinct in their increased expression of drug-resistant genes.More intriguingly,by using the FGNP-based FACS assay to detect DR/non-DR phenotypes,we found that the DR phenotype had a potential to differentiate into the non-DR progeny,which demonstrates the differentiation feature of stem-like cancer cells.Further research disclosed that the assay can quantitatively detect the degree of drug resistance in DR cells,as well as the reversal of drug resistance that are tackled by various therapeutic methods.The strategy thus paves the way to develop theranostic approaches associated with chemotherapy-resistance and cancer stemness. | Chenglong Wang Wencai Guan Rong Chen Yael Levi-Kalisman Yichun Xu Liwen Zhang Min Zhou Guoxiong Xu Hongjing Dou | 2020 | Nano Research2020，13，11： | 0 |
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