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Investigation of a dynamics-oriented engineering approach to ultraprecision machining of freeform surfaces and its implementation perspectives

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Nanotechnology and Precision Engineering 2021年第4期4卷 12-23页

作者： Ali Khaghani Kai Cheng Department of Mechanical and Aerospace Engineering(MAE) Brunel University LondonKingston LaneUxbridge UB83PHUnited Kingdom

In current precision and ultraprecision machining practice,the positioning and control of actuation systems,such as slideways and spindles,are heavily dependent on the use of linear or rotary ***,positioning control is passive because of the lack of direct monitoring and control of the tool and workpiece positions in the dynamic machining process and also because it is assumed that the machining system is rigid and the cutting dynamics are *** ultraprecision machining of freeform surfaces using slow tool servo mode in particular,however,account must be taken of the machining dynamics and dynamic synchronization of the cutting tool and workpiece *** important question also arises as to how ultraprecision machining systems can be designed and developed to work better in this application *** this paper,an innovative dynamics-oriented engineering approach is presented for ultraprecision machining of freeform surfaces using slow tool servo *** approach is focused on seamless integration of multibody dynamics,cutting forces,and machining dynamics,while targeting the positioning and control of the tool–workpiece loop in the machining *** positioning and motion control between the cutting tool and workpiece surface are further studied in the presence of interfacial interactions at the tool tip and workpiece *** interfacial cutting physics and dynamics are likely to be at the core of in-process monitoring applicable to ultraprecision machining *** approach is illustrated using a virtual machining system developed and supported with simulations and experimental ***,the paper provides further explorations and discussion on implementation perspectives of the approach,in combination with case studies,as well as discussing its fundamental and industrial implications.

关键词： ultraprecision machining Freeform surface Dynamics-oriented approach Dynamic cutting force Slow tool servo mode Microcutting

Micro-optical fabrication by ultraprecision diamond machining and precision molding

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Frontiers of Mechanical Engineering 2017年第2期12卷 181-192页

作者： Likai LI Neil J. NAPLES Jeffrey W. ROBLEE Allen Y. YI Department of Integrated System Engineering The Ohio StateUniversity Columbus OH 43210 USA Nistica Inc. Bridgewater NJ 08807 USA Ametek Precitech Keene NH 03431 USA

ultraprecision diamond machining and high volume molding for affordable high precision high performance optical elements are becoming a viable process in optical industry for low cost high quality microoptical component manufacturing. In this process, first high precision microoptical molds are fabricated using ultraprecision single point diamond machining followed by high volume production methods such as compression or injection molding. In the last two decades, there have been steady improvements in ultraprecision machine design and performance, particularly with the introduction of both slow tool and fast tool servo. Today optical molds, including freeform surfaces and microlens arrays, are routinely diamond machined to final finish without post machining polishing. For consumers, compression mold- ing or injection molding provide efficient and high quality optics at extremely low cost. In this paper, first ultrapreci- sion machine design and machining processes such as slow tool and fast too servo are described then both compression molding and injection molding of polymer optics are discussed. To implement precision optical manufacturing by molding, numerical modeling can be included in the future as a critical part of the manufacturing process to ensure high product quality.

关键词： ultraprecision machining slow tool servo fast tool servo compression molding injection molding,microlens arrays optical fabrication

Design and fabrication of a gecko-inspired surface for improving the grasping ability of a humanoid dexterous hand

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Science China(Technological Sciences) 2023年第3期66卷 784-792页

作者： JIANG ZhiHong SHEN MingHui MA YiFan CHE JiangTao LI Hui School of Mechatronic Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing 100081China Key Laboratory of Biomimetic Robots and Systems Ministry of EducationBeijing 100081China China Electronics Standardization Institute Beijing 100007China

Many studies have examined the design,fabrication and characteristics of gecko-inspired adhesives,but applied research on gecko-inspired surfaces in humanoid dexterous hands is relatively ***,a wedged slanted structure with a curved substrate suitable for humanoid dexterous fingers was designed and manufactured via ultraprecision machining and replica *** adhesion and friction properties of the wedged slanted structure show obvious anisotropic characteristics in the gripping and releasing directions,and the influence of structural parameters and motion parameters on the adhesion and friction was systematically *** humanoid dexterous fingers with gecko-inspired surfaces greatly increased the grasping force limit(increase to 4.02 times)based on the grasping of measuring cups with different volumes of water and improved the grasping stability based on the picking up of smooth steel balls of different *** study shows that this process,based on ultraprecision machining and replica molding,is a green,high-efficiency,and low-cost method to fabricate large-area biomimetic surfaces that has potential applications in dexterous humanoid hands to improve grasping ability,stability and adaptability.

关键词： gecko-inspired surface curved substrate ultraprecision machining friction humanoid dexterous hand

Tool path generation and optimization for freeform surface diamond turning based on an independently controlled fast tool servo

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International Journal of Extreme Manufacturing 2022年第2期4卷 145-160页

作者： Yusuke Sato Jiwang Yan Department of Mechanical Engineering Keio UniversityYokohama 223-8522Japan

Diamond turning based on a fast tool servo(FTS)is widely used in freeform optics fabrication due to its high accuracy and machining *** a new trend,recently developed high-frequency and long-stroke FTS units are independently driven by a separate control system from the machine tool ***,the tool path generation strategy for the independently controlled FTS is far from *** study aims to establish methods for optimizing tool path for the independent control FTS to reduce form errors in a single step of *** from the conventional integrated FTS control system,where control points are distributed in a spiral pattern,in this study,the tool path for the independent FTS controller is generated by the ring method and the mesh method,*** machined surface profile is predicted by simulation and the parameters for the control point generation are optimized by minimizing the deviation between the predicted and the designed *** demonstrate the feasibility of the proposed tool path generation strategies,cutting tests of a two-dimensional sinewave and a micro-lens array were conducted and the results were *** a result,after tool path optimization,the peak-to-valley form error of the machined surface was reduced from 429 nm to 56 nm for the two-dimensional sinewave by using the ring method,and from 191 nm to 103 nm for the micro-lens array by using the mesh method,respectively.

关键词： ultraprecision machining diamond turning fast tool servo freeform surface tool path optimization

Fabrication of Microlens Array and Its Application:A Review

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Chinese Journal of Mechanical Engineering 2018年第1期31卷 10-18页

作者： Wei Yuan Li-Hua Li Wing-Bun Lee Chang-Yuen Chan State Key Laboratory of Ultra-precision machining Technology Partner Laboratory in the Hong Kong Polytechnic University Shenzhen Branch of State Key Laboratory of Ultra-precision machining Technology PolyU Shenzhen Research Institute

Microlens arrays are the key component in the next generation of 3D imaging system, for it exhibits some good optical properties such as extremely large field of view angles, low aberration and distortion, high temporal resolution and infinite depth of field. Although many fabrication methods or processes are proposed for manufacturing such precision component, however, those methods still need to be improved. In this review, those fabrication methods are categorized into direct and indirect method and compared in detail. Two main challenges in manufacturing microlens array are identified: how to obtain a microlens array with good uniformity in a large area and how to produce the microlens array on a curved surface? In order to effectively achieve control of the geometry of a microlens,indirect methods involving the use of 3D molds and replication technologies are suggested. Further development of ultraprecision machining technology is needed to reduce the surface fluctuation by considering the dynamics of machine tool in tool path planning. Finally, the challenges and opportunities of manufacturing microlens array in industry and academic research are discussed and several principle conclusions are drawn.

关键词： Microlens array ultraprecision machining 3D image system MEMS

Ultra-precision machining of cerium-lanthanum alloy with atmosphere control in an auxiliary device

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Nanotechnology and Precision Engineering 2022年第3期5卷 30-35页

作者： Chenyu Zhao Shengjie Wu Min Lai State Key Laboratory of Precision Measuring Technology and Instruments Laboratory of Micro/Nano Manufacturing TechnologyTianjin UniversityTianjin 300072China

Cerium–lanthanum alloys are the main component of nickel–metal hydride batteries,and they are thus an important material in the greenenergy ***,these alloys have very strong chemical activity,and their surfaces are easily oxidized,leading to great difficulties in their *** improve the corrosion resistance of cerium–lanthanum alloys,it is necessary to obtain a nanoscale surface with low ***,these alloys can easily succumb to spontaneous combustion during ***,to inhibit the occurrence of fire,machining of this alloy in ambient air needs to be conducted at very low cutting speeds while spraying the workpiece with a large amount of cutting ***,this is inefficient,and only a very limited range of parameters can be optimized at low cutting speeds;this restricts the optimization of other cutting *** achieve ultraprecision machining of cerium–lanthanum alloys,in this work,an auxiliary machining device was developed,and its effectiveness was *** results show that the developed device can improve the cutting speed and obtain a machined surface with low *** device can also improve the machining efficiency and completely prevent the occurrence of spontaneous *** was found that the formation of a build-up of swarf on the cutting tool is eliminated with high-speed cutting,and the surface roughness(Sa)can reach 5.64 nm within the selected ***,the oxidation processes of the cerium–lanthanum alloy and its swarf were studied,and the process of the generation of oxidative products in the swarf was *** results revealed that most of the intermediate oxidative products in the swarf were Ce^(3+),there were major oxygen vacancies in the swarf,and the final oxidative product was Ce^(4+).

关键词： Cerium–lanthanum alloy ultraprecision machining Surface roughness Atmosphere control

TOOL FORCE MODEL FOR DIAMOND TURNING

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Chinese Journal of Mechanical Engineering 2004年第1期17卷 145-148页

作者： WangHongxiang SunTao LiDan DongShen SchoolofMechanicalandElectricalEngineering HarbinInstituteofTechnologyHarbin150001China PrecisionEngineenngResearchInstitute HarbinInstituteofTechnologyHarbin150001China SchoolofMechanicalandElectricalEngineenng HarbinInstituteofTechnologyHarbin150001China PrecisionEngineenngResearcnInstitute HarbinInstituteofTechnologyHarbin150001China

A new tool force model to be presented is based upon process geometry and thecharacteristics of the force system, in which the forces acting on the tool rake face, the cuttingedge rounding and the clearance face have been considered, and the size effect is accountable forthe new model. It is desired that the model can be well applicable to conventional diamond turningand the model may be employed as a tool in the design of diamond tools. This approach is quitedifferent from traditional investigations primarily based on empirical studies. As the depth of cutbecomes the same order as the rounded cutting edge radius, sliding along the clearance face due toelastic recovery of workpiece material and plowing due to the rounded cutting edge may becomeimportant in micro-machining, the forces acting on the cutting edge rounding and the clearance facecan not be neglected. For this reason, it is very important to understand the influence of someparameters on tool forces and develop a model of the relationship between them.

关键词： ultraprecision machining Tool force Diamond turning

Effect of Tool Geometry in Nanometric Cutting

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厦门大学学报（自然科学版） 2002年第S1期41卷 16-17页

作者： HAN Xue-song, LIN Bin, YU Si-yuan, LIN Mon-xia (The State Education Ministry Key Laboratory of High Temperature Structure Ceramics and machining Technology of Engineering Ceramics, Tianjin University, Tianjin 300072, China)

With the development of science and technology, the ultra-precision manufacturing of the brittle and hard materials with superior quality have become a new attractive subject. Brittle materials (such as engineering ceramics, optical glass, semiconductor and so on) are widely used in electronics, optics, aeronautics and other high technology fields, so there are important theory significance and practical value to systematically study its machining mechanism and technology. Single crystal silicon is one of the typical brittle materials. Single crystal silicon wafer is a basic component of large and ultralarge integrated the circuit, its surface roughness and flatness are the key factor of improving its integration. With the successfully producing of the large diameter single crystal silicon wafer, its manufacturing technology became attractive subject again. This paper carries out computer simulation of nanometer cutting on single crystal silicon. Molecular Dynamics method which is different from continuous mechanics is employed to investigate the features of grinding energy dissipation, grinding force, stress state and grinding temperature, constructs the atom model of tool and work piece, and explains the microscale mechanism of material remove and surface generation of nanometer(subnanometer) manufacturing. This paper also investigates the variation of cutting force, thrust force, specific energy and surface deformation with different tool edge radius, different depth of cut.

关键词： single crystal silicon ultraprecision machining manufacturing mechanism molecular dynamics computer simulation