Compliant grinding and polishing: A review Zhu, Wu-Le; Beaucamp, Anthony
International journal of machine tools & manufacture,
November 2020, 2020-11-00, 20201101, Volume:
158
Journal Article
Peer reviewed
Compliant grinding and polishing refers to a class of fine material processing methods relying on one or more system element being compliant with the workpiece surface in a controllable and ...reversible manner, thus being distinct from conventional rigid wheel grinding and polishing. The resulting surface adaptability greatly facilitates the ultra-precision machining of freeform surfaces, with a level of accuracy and productivity difficult to achieve with conventional rigid processing systems. Aiming for a comprehensive review of signal advances on this topic in the last decades, this paper introduces a multi-level compliance categorization system to sort between distinctive processes. For each category, various perspectives are explored that pertain to principles, methodologies, and physical properties such as material removal and surface integrity. Finally, relative merits are analyzed, together with a discussion of the outlook and future trends.
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•Compliant grinding and polishing are categorized into 5 levels that span the closed-loop of complete machine component chain.•Within each category, sub-levels including passive and active systems are described and qualitatively compared.•The respective domains on achievable removal rate and surface roughness are quantified, with appropriate areas of application.•Efforts to combine multiple compliance levels into hybrid finishing processes are mentioned.
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•The automatic non-contact calibration process of dynamic workpiece coordinate frame in the robot grinding system is realized.•The idea of six-point limit is introduced into the dynamic workpiece ...coordinate frame calibration process by using a point laser displacement sensor.•An economical and practical calibration method of the point laser displacement sensor coordinate frame is proposed.•The multi-dimensional minimal optimization algorithm is applied to the blade calibration process and some improvements are implemented.
Automatic robotic grinding and polishing systems have become a developing trend in aerospace parts manufacturing. In a robotic blade grinding and polishing system (RBGPS), the automatic and precise calibration of the dynamic workpiece coordinate frame is the most important process. In this research, a new method that introduces the concept of six-point positioning into the dynamic workpiece coordinate frame calibration process is proposed using a point laser displacement sensor (PLDS). The static coordinate frame calibration process is conducted based on a robot flange and force sensor. The results indicate that the new method can achieve a higher precision calibration result and has improved operational efficiency and cost. Finally, its practicality is verified in the BRGPS, and the results indicate that the polished blade surface after using the new method has good consistency.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract Background There is insufficient clinical and microbiological evidence to support the use of diode laser and air-polishing with erythritol as supplements to scaling and root planning(SRP). ...The aim of the current study is to evaluate the clinical and microbiologic efficacy of erythritol subgingival air polishing and diode laser in treatment of periodontitis. Methods The study encompassed twenty-four individuals seeking periodontal therapy and diagnosed with stage I and stage II periodontitis. Eight patients simply underwent SRP. Eight more patients had SRP followed by erythritol subgingival air polishing, and eight patients had SRP followed by diode laser application. At baseline and six weeks, clinical periodontal parameters were measured, including Plaque Index (PI), Gingival Index (GI), periodontal Probing Depth (PPD), and Clinical Attachment Level (CAL). The bacterial count of Aggregatibacter actinomycetemcomitans(A.A), Porphyromonas gingivalis (P.G) was evaluated at different points of time. Results The microbiological assessment revealed significant differences in the count of A.A. between the laser and erythritol groups immediately after treatment, indicating a potential impact on microbial levels. However, the microbial levels showed fluctuations over the subsequent weeks, without statistically significant differences. Plaque indices significantly decreased post-treatment in all groups, with no significant inter-group differences. Gingival indices decreased, and the laser group showed lower values than erythritol and control groups. PPD and CAL decreased significantly across all groups, with the laser group exhibiting the lowest values. Conclusion The supplementary use of diode laser and erythritol air polishing, alongside SRP, represents an expedited periodontal treatment modality. This approach leads to a reduction in bacteria and improvement in periodontal health. Trial registration This clinical trial was registered on Clinical Trials.gov (Registration ID: NCT06209554) and released on 08/01/2024.
Due to ever increasing precision and automation demands in robotic grinding, the automatic and robust robotic grinding workstation has become a research hot-spot. This work proposes a grinding ...workstation constituting of machine vision and an industrial manipulator to solve the difficulty of positioning rough metal cast objects and automatic grinding. Faced with the complex characteristics of industrial environment, such as weak contrast, light nonuniformity and scarcity, a coarse-to-fine two-step localization strategy was used for obtaining the object position. The deep neural network and template matching method were employed for determining the object position precisely in the presence of ambient light. Subsequently, edge extraction and contour fitting techniques were used to measure the position of the contour of the object and to locate the main burr on its surface after eliminating the influence of burr. The grid method was employed for detecting the main burrs, and the offline grinding trajectory of the industrial manipulator was planned with the guidance of the coordinate transformation method. The system greatly improves the automaticity through the entire process of loading, grinding and unloading. It can determine the object position and target the robotic grinding trajectory by the shape of the burr on the surface of an object. The measurements indicate that this system can work stably and efficiently, and the experimental results demonstrate the high accuracy and high efficiency of the proposed method. Meanwhile, it could well overcome the influence of the materials of grinding work pieces, scratch and rust.
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Metrology has been successfully used in the last decade to quantify use-wear on stone tools. Such techniques have been mostly applied to fine-grained rocks (chert), while studies on coarse-grained ...raw materials have been relatively infrequent. In this study, confocal microscopy was employed to investigate polished surfaces on a coarse-grained lithology, quartzite. Wear originating from contact with five different worked materials were classified in a data-driven approach using machine learning. Two different classifiers, a decision tree and a support-vector machine, were used to assign the different textures to a worked material based on a selected number of parameters (Mean density of furrows, Mean depth of furrows, Core material volume-Vmc). The method proved successful, presenting high scores for bone and hide (100%). The obtained classification rates are satisfactory for the other worked materials, with the only exception of cane, which shows overlaps with other materials. Although the results presented here are preliminary, they can be used to develop future studies on quartzite including enlarged sample sizes.
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Grinding is the last and most important process of parts processing, the purpose is to achieve high precision and surface roughness. Therefore, grinding machine has the characteristics of high added ...value, high technology content and great remanufacturing value. However, the evaluation of machine tool remanufacturing is based on imprecise and fuzzy information at present. The aim of this study is to present the remanufacturing evaluation for feasibility and comprehensive benefit of retired grinder. Firstly, according to the unique structure of grinder, the feasibility evaluation model of grinder remanufacturing is established, including technical feasibility criterion, economic feasibility criterion and resource environment feasibility criterion. Secondly, the comprehensive benefit evaluation model of remanufacturing grinder is established, in which the weight of each evaluation criterion is determined by Analytic Hierarchy Process (AHP). Finally, combined with the remanufacturing case of the cylindrical grinder, the evaluation method is verified and analyzed. The results show that the remanufacturing of the waste grinding machine through the feasibility evaluation can obtain better comprehensive benefits, and the remanufacturer can get considerable benefits and reduce the potential risks in the remanufacturing process.
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We propose and demonstrate a reflective-distributed surface plasmon resonance (SPR) sensor based on the twin-core fiber. Firstly, we study the effects of the fiber dual tapered (DT) probe grinding ...angle on the SPR dynamic range. The results show that for larger grinding angles, the resonance wavelength increases, resulting in a higher testing sensitivity. By using this method, we can make the sensor operate in an optimal waveband. Secondly, on the basis of the results above, we grind the DT probe to be an asymmetric wedge shape to configure two grinding angles (6° and 17°) to realize the distributed sensing. Results show that, with the refractive index detecting a range of 1.333–1.385, we can get two separated sensing zones, 591–715nm and 729–966nm, the testing sensitivity are 2385nm/RIU and 4558nm/RIU respectively. By using this method, we can detect multiple analytes in the same sensing area simultaneously, besides that we can also effectively compensate for the errors caused by background index interference, and the refractive index change resulting from the non-specific binding, or physical absorption and others. It worth to say that by using this method, we can adjust and control the resonance wavelength by changing the fiber grinding angle, while keeping the testing sensitivity is not reduced. For practical applications, this reflective distributed fiber-based sensor is much suitable for biochemical sensing, it has small size and can enter a small testing spaces (μm scale). The diameter of the twin-core fiber is the only 125μm, which helps to be integrated into a micro-fluidic chip. In this paper, we integrate the fiber probe into an infusion needle to simulate blood vessels on-line monitoring.
•We employ a twin-core single mode fiber to realize the distributed SPR sensing.•The twin cores in the fiber are geometry symmetry in the spatial structure, which is convenient for the sensing beam launching and receiving.•The twin cores diameter meets the single mode propagating condition.•Thus, only a fundamental mode beam can propagate in the fiber core, the sensitivity can be greatly improved.•The twin-core fiber is ground to be a DT shape, which helps to realize the Kretschmann configurations for sensing.
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This book provides insights into modern grinding technology based on wide research and experience. It provides a concise treatment of the principles involved and shows how these lead on to the latest ...technology developments. The reader learns how to achieve high precision, fast removal rates, and reduced costs. Every aspect of the grinding process and machine comes under the searchlight to show step improvements.
Superb grinding machines now produce optical quality finishes due to developments in process control and machine design. It is the same for extremely high removal rates. This book shows how best quality can be improved and costs brought down at the same time as output is increased. The book is aimed at practitioners, engineers, researchers, students, and teachers. The approach is direct, concise and authoritative. Progressing through each major element of the grinding system and then on to machine developments and process control, the reader becomes aware of all aspects of operation and design. Trends are described demonstrating key features.
In order to realize the active and compliant motion of the robot, it is necessary to eliminate the impact caused by processing contact. A hybrid control strategy for grinding and polishing robot is ...proposed based on adaptive impedance control. Firstly, an electrically driven linear end effector is designed for the robot system. The macro and micro motions control model of the robot is established, by using impedance control method, which based on the contact model of the robot system and the environment. Secondly, the active compliance method is adopted to establish adaptive force control and position tracking control strategies under impact conditions. Finally, the algorithm is verified by Simulink simulation and experiment. The simulation results are as follows: The position tracking error does not exceed 0.009 m, and the steady-state error of the force is less than 1 N. The experimental results show that the motion curve coincides with the surface morphology of the workpiece, and the contact force is stable at 10 ± 3 N. The algorithm can realize more accurate position tracking and force tracking, and provide a reference for the grinding and polishing robot to realize surface processing.
In order to improve surface quality and reduce surface roughness of integrally bladed rotors (IBRs), the optimizations of grinding and polishing process parameters, such as abrasive size, contact ...force, belt linear velocity, and feed rate, are carried out in this study. Firstly, the optimal range of each factor is obtained by single-factor experiment, and a surface roughness prediction model is generated according to the central composite design experiments and quadratic regression design technology. Secondly, the optimal level of each factor is confirmed through the surface roughness prediction model, and the response surface of the optimal level of each factor is drawn using Matlab. Then, the optimum process parameters are determined by analyzing the response surface. Finally, the optimum process parameters are selected in the grinding and polishing experiments for IBR. The experimental results show that grinding and polishing with the optimum parameters obtained in this study enhances the machining quality significantly. The surface roughness of IBR improved greatly (nearly 25 %) compared with grinding using normal parameters.
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