High mechanical advantage as well as low and steady slide speed within the working stroke Sn are the fundamental requirements for the working mechanism of servo-mechanical press. Currently, the Crank-Triangular Linkage-Elbow (CTLE) mechanism has attracted more and more attention from researchers and manufacturers of servo presses. This paper presents a new analysis and design method of CTLE. The mechanism is decomposed into two sub-units: crank and triangular-linkage elbow, followed by the kinematic and force analysis of each sub-unit. The influences of each structural parameter on the working performance are obtained and can be used as the basis for preliminary design. Through the offset design, the mechanical advantage peaks of the two units, MA1max and MA2max, do not occur at the same time: MA1max is located near Sn, while MA2max is just at BDC (Bottom Dead Center). Because the mechanical advantage of the whole mechanism is the product of the two subunits, the designed mechanism can obtain high and steady mechanical advantage together with low and steady slide speed within Sn. After preliminary design, the scheme can be further modified by numerical simulation and optimization. Hence the design efficiency can be improved.
高的机械优势和在工作行程Sn内低而稳定的滑动速度是伺服机械压力机工作机构的基本要求。目前，曲柄-三角连杆-弯头(CTLE)机构越来越受到伺服压力机研究者和制造商的关注。本文提出了一种新的CTLE分析与设计方法。将机构分解为曲柄和三角连杆弯头两个子单元，并对每个子单元进行运动学和受力分析。得到了各结构参数对工作性能的影响，可作为初步设计的依据。通过偏置设计，MA1max和MA2max两个单元的机械优势峰值不会同时出现:MA1max位于Sn附近，而MA2max刚好位于BDC (Bottom Dead Center)。由于整个机构的机械优势是两个亚单元的乘积，因此设计的机构可以在Sn范围内获得高而稳定的机械优势和低而稳定的滑动速度。初步设计完成后，可通过数值模拟和优化对方案进行进一步修改。从而提高了设计效率。
{"title":"Decomposition analysis and peak stagger design for Crank-triangular linkage-elbow mechanism of mechanical servo presses","authors":"Y. Sun, J. Hu, Lian Wei, Yongqi Chen","doi":"10.1051/meca/2021042","DOIUrl":"https://doi.org/10.1051/meca/2021042","url":null,"abstract":"High mechanical advantage as well as low and steady slide speed within the working stroke Sn are the fundamental requirements for the working mechanism of servo-mechanical press. Currently, the Crank-Triangular Linkage-Elbow (CTLE) mechanism has attracted more and more attention from researchers and manufacturers of servo presses. This paper presents a new analysis and design method of CTLE. The mechanism is decomposed into two sub-units: crank and triangular-linkage elbow, followed by the kinematic and force analysis of each sub-unit. The influences of each structural parameter on the working performance are obtained and can be used as the basis for preliminary design. Through the offset design, the mechanical advantage peaks of the two units, MA1max and MA2max, do not occur at the same time: MA1max is located near Sn, while MA2max is just at BDC (Bottom Dead Center). Because the mechanical advantage of the whole mechanism is the product of the two subunits, the designed mechanism can obtain high and steady mechanical advantage together with low and steady slide speed within Sn. After preliminary design, the scheme can be further modified by numerical simulation and optimization. Hence the design efficiency can be improved.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73957069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forming sheet metals under blast loading or the explosive forming technique has many advantages for productions, but it is restricted due to its accuracy. This paper introduces a novel theoretical-empirical study for explosive sheet metal forming based on the simple plasticity principles. It provides a method of producing the sheet metal cone parts forming under blast loading, including an analytical model and experimental validation. Firstly, a theoretical-empirical model for cone forming based on underwater explosion employing the impulse method is developed. The model on the whole revealed the relationships among the geometrical parameters of forming a process that is very useful to predict the certain explosive mass for complete forming a cone part. Afterward, a series of experiments are conducted to validate the developed model and also for the required modification in the solution. Comparing the theoretical-empirical solution and experimental results, the ability of the presented model for estimation of the explosive mass is demonstrated. Experimental results show that the theoretical model matched the experiments well.
{"title":"Physically-based modelling for sheet metal cone parts forming under blast loading","authors":"R. Alipour","doi":"10.1051/MECA/2021002","DOIUrl":"https://doi.org/10.1051/MECA/2021002","url":null,"abstract":"Forming sheet metals under blast loading or the explosive forming technique has many advantages for productions, but it is restricted due to its accuracy. This paper introduces a novel theoretical-empirical study for explosive sheet metal forming based on the simple plasticity principles. It provides a method of producing the sheet metal cone parts forming under blast loading, including an analytical model and experimental validation. Firstly, a theoretical-empirical model for cone forming based on underwater explosion employing the impulse method is developed. The model on the whole revealed the relationships among the geometrical parameters of forming a process that is very useful to predict the certain explosive mass for complete forming a cone part. Afterward, a series of experiments are conducted to validate the developed model and also for the required modification in the solution. Comparing the theoretical-empirical solution and experimental results, the ability of the presented model for estimation of the explosive mass is demonstrated. Experimental results show that the theoretical model matched the experiments well.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90928310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the set of factors and conditions, the stream pressure through the orifice decreases, which can lead to the occurrence of the cavitation phenomenon. The most important factor in this regard is the geometry of orifice. In the first part of this study, the flow through two types of single-hole orifice and a multi-hole orifice were experimentally studied. The results showed that the single hole orifice with a two-sided sloped edge caused less pressure drop, which in order to control the cavitation phenomenon is more efficient compared to the single-hole and multi-hole orifices with one-sided sloped edges and the same equal diameter ratio. Additionally, all experiments were simulated in the second part of this research using finite volume methods. Considering the complexity of the problem, several numerical solutions were investigated to approach the experimental results. Finally, it was determined that the type of gridding, turbulence method, and cavitation model have a great influence on the accuracy of the obtained numerical results.
{"title":"Experimental and numerical investigation of geometric effect on cavitation flow through orifice","authors":"Mohammad Reza Davoudi, Miralam Mahdi","doi":"10.1051/MECA/2021018","DOIUrl":"https://doi.org/10.1051/MECA/2021018","url":null,"abstract":"Due to the set of factors and conditions, the stream pressure through the orifice decreases, which can lead to the occurrence of the cavitation phenomenon. The most important factor in this regard is the geometry of orifice. In the first part of this study, the flow through two types of single-hole orifice and a multi-hole orifice were experimentally studied. The results showed that the single hole orifice with a two-sided sloped edge caused less pressure drop, which in order to control the cavitation phenomenon is more efficient compared to the single-hole and multi-hole orifices with one-sided sloped edges and the same equal diameter ratio. Additionally, all experiments were simulated in the second part of this research using finite volume methods. Considering the complexity of the problem, several numerical solutions were investigated to approach the experimental results. Finally, it was determined that the type of gridding, turbulence method, and cavitation model have a great influence on the accuracy of the obtained numerical results.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90441313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The presence of flexibilities in rotational joints can limit the kinematic performances of manipulators doing high speed tasks as Pick and Place. The problem addressed in this work concerns the vibration control of serial robots with flexible joints performing Pick and Place tasks in order to improve productivity. Based on a dynamic model of a robot with flexible joints, a model-based control law is proposed with its associated tuning methodology. The robot dynamic model is then the key point of our methodology. This dynamic model considers stiffness and damping of each flexible joint. To guarantee its accuracy, a geometrical and dynamic identification procedure is realized. The objective is to show the relevancy of the proposed approach which integrates joint flexibilities in the control law. Theoretical results based on a representative model are used to illustrate the benefit of this model-based control law compare to two other control strategies (Feedforward control and control dedicated to rigid structures). Finally, a sensitivity analysis of this control law is realized to quantify the impact of modelling error and conclude on the criticality of joint damping value on vibration decreasing.
{"title":"A model-based control law for vibration reduction of serial robots with flexible joints","authors":"Jacques Farah, H. Chanal, N. Bouton, V. Gagnol","doi":"10.1051/meca/2021036","DOIUrl":"https://doi.org/10.1051/meca/2021036","url":null,"abstract":"The presence of flexibilities in rotational joints can limit the kinematic performances of manipulators doing high speed tasks as Pick and Place. The problem addressed in this work concerns the vibration control of serial robots with flexible joints performing Pick and Place tasks in order to improve productivity. Based on a dynamic model of a robot with flexible joints, a model-based control law is proposed with its associated tuning methodology. The robot dynamic model is then the key point of our methodology. This dynamic model considers stiffness and damping of each flexible joint. To guarantee its accuracy, a geometrical and dynamic identification procedure is realized. The objective is to show the relevancy of the proposed approach which integrates joint flexibilities in the control law. Theoretical results based on a representative model are used to illustrate the benefit of this model-based control law compare to two other control strategies (Feedforward control and control dedicated to rigid structures). Finally, a sensitivity analysis of this control law is realized to quantify the impact of modelling error and conclude on the criticality of joint damping value on vibration decreasing.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79644815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Effects of various clearances of variable-pitch screw vacuum pump on gas backflow of internal flow field of the pump cavity is studied. The theoretical tooth surfaces of screw rotor are optimized by radial, normal equidistance modifications, and four types of stable clearances of rotor circumferential, radial, tooth shape and tooth sides are obtained. The backflow calculation model in clearances considering Couette backflow and orifice backflow is improved. The three-dimensional model of variable-pitch screw vacuum pump is designed, and the experimental prototype and test device are developed. The internal backflow of vacuum pump is analyzed by using the commercial software Ansys-Fluent® and the calculation model. The results show that the smaller the clearances, the smaller the backflow and the higher the vacuum degree. Among the four types of clearances, the circumferential clearance plays the primary roles. The backflow is directly proportional to the inlet pressure and rotating speed. Predictions are validated by the experimental data with satisfied agreement.
{"title":"Effects of stable clearances on backflow in the variable-pitch screw vacuum pump","authors":"Li Zhang, Yongju Zhang, Ziyun Chen","doi":"10.1051/meca/2021046","DOIUrl":"https://doi.org/10.1051/meca/2021046","url":null,"abstract":"Effects of various clearances of variable-pitch screw vacuum pump on gas backflow of internal flow field of the pump cavity is studied. The theoretical tooth surfaces of screw rotor are optimized by radial, normal equidistance modifications, and four types of stable clearances of rotor circumferential, radial, tooth shape and tooth sides are obtained. The backflow calculation model in clearances considering Couette backflow and orifice backflow is improved. The three-dimensional model of variable-pitch screw vacuum pump is designed, and the experimental prototype and test device are developed. The internal backflow of vacuum pump is analyzed by using the commercial software Ansys-Fluent® and the calculation model. The results show that the smaller the clearances, the smaller the backflow and the higher the vacuum degree. Among the four types of clearances, the circumferential clearance plays the primary roles. The backflow is directly proportional to the inlet pressure and rotating speed. Predictions are validated by the experimental data with satisfied agreement.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78313183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jun Li, H. Gurgenci, Jishun Li, Z. Guan, Lun Li, Y. Xue
Numerical investigation was carried out to study the heat transfer performance for a high-speed rotating cylindrical surface subjected to single row array round jets impingement, under a very small gap spacing. Various parameters that affect heat transfer, such as the fluid density, flow velocity and Nusselt number distributions of the radius clearance were studied based on varied nozzle to target surface spacing H and mass flow rate. It has been found that the fluid density was a dominant factor and the velocity was the secondary factor for the gas jet heat transfer performances. The overall heat transfer was improved with a reduction in the number of nozzles, for given inlet mass flow rate boundary conditions. The decrease of H/di (di, nozzle diameter) may have positive or negative effects on the heat transfer performance from the impingement surface. Reducing the radius gap H, for a certainty, increases the average density of the fluid in the clearance, which is desirable in applications that enhance heat transfer performance. But when the radius gap (H) is small enough, increasing di may have a negative impact on heat transfer.
{"title":"Numerical investigation on the cooling performance of a novel jet cooler design for a supercritical CO2 turbine rotor shaft cooling","authors":"Jun Li, H. Gurgenci, Jishun Li, Z. Guan, Lun Li, Y. Xue","doi":"10.1051/meca/2021049","DOIUrl":"https://doi.org/10.1051/meca/2021049","url":null,"abstract":"Numerical investigation was carried out to study the heat transfer performance for a high-speed rotating cylindrical surface subjected to single row array round jets impingement, under a very small gap spacing. Various parameters that affect heat transfer, such as the fluid density, flow velocity and Nusselt number distributions of the radius clearance were studied based on varied nozzle to target surface spacing H and mass flow rate. It has been found that the fluid density was a dominant factor and the velocity was the secondary factor for the gas jet heat transfer performances. The overall heat transfer was improved with a reduction in the number of nozzles, for given inlet mass flow rate boundary conditions. The decrease of H/di (di, nozzle diameter) may have positive or negative effects on the heat transfer performance from the impingement surface. Reducing the radius gap H, for a certainty, increases the average density of the fluid in the clearance, which is desirable in applications that enhance heat transfer performance. But when the radius gap (H) is small enough, increasing di may have a negative impact on heat transfer.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75739641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The finger skin contains a variety of receptors, which provide multiple tactile sensing channels. When a finger touches the surface of an object, people can simultaneously perceive curvature, texture, softness, temperature, and so on. However, in most of research activities, the designed haptic feedback devices can only focus on a certain channel. In this paper, the rendering of curved and periodic textured surfaces involving two channels, i.e., curvature and texture, was studied. Two psychophysical experiments were conducted to investigate whether the coupling of kinesthetic feedback of curvature and tactile feedback of texture could reproduce curved and textured surfaces with high fidelity. The results showed a deviation of the point of subjective equality values in terms of curvature and roughness, indicating that the curvature rendering and texture rendering have an impact on each other. Therefore, it is necessary to correct the bias when making virtual rendering. The influence of curvature on texture rendering is reduced by recalculating and adjusting the spatial period of the synthesized texture in real-time; the influence of texture on curvature rendering is eliminate by compensating the force difference between touch on physical strip and artificial stimulus.
{"title":"Combination of oriented-plane curvature reproduction and squeeze film effect-based texture reproduction to simulate curved and textured surface","authors":"Tao Zeng, Yan Liu, Enshan Ouyang","doi":"10.1051/MECA/2021024","DOIUrl":"https://doi.org/10.1051/MECA/2021024","url":null,"abstract":"The finger skin contains a variety of receptors, which provide multiple tactile sensing channels. When a finger touches the surface of an object, people can simultaneously perceive curvature, texture, softness, temperature, and so on. However, in most of research activities, the designed haptic feedback devices can only focus on a certain channel. In this paper, the rendering of curved and periodic textured surfaces involving two channels, i.e., curvature and texture, was studied. Two psychophysical experiments were conducted to investigate whether the coupling of kinesthetic feedback of curvature and tactile feedback of texture could reproduce curved and textured surfaces with high fidelity. The results showed a deviation of the point of subjective equality values in terms of curvature and roughness, indicating that the curvature rendering and texture rendering have an impact on each other. Therefore, it is necessary to correct the bias when making virtual rendering. The influence of curvature on texture rendering is reduced by recalculating and adjusting the spatial period of the synthesized texture in real-time; the influence of texture on curvature rendering is eliminate by compensating the force difference between touch on physical strip and artificial stimulus.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76039215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frame saw machine is one of machine tools that is used to process dimension stone. The velocity fluctuation of traditional feed drive system (FDS) lead to excessive wear of diamond particles. The dynamic performance of the FDS has time-varying characteristics during the processing of stone with a large material removal rate. In this paper, a novel FDS was proposed. Firstly, the dynamic modeling of FDS was set up on account of lumped parameter method (LPM). Then the speed of the new FDS was compared with that of the traditional FDS. Finally, the frequency response characteristics of the system were solved by Lagrange and state space method. Results showed that the new FDS has a faster response feed and less velocity fluctuation. The natural frequency and the amplitude of acceleration increase with decreasing load. With the time-varying load, the range of the second-order natural frequency increased by 50 Hz, which was larger than that of the first-order. The modal test verified that the first two natural frequencies of the saw blade are within the range of the natural frequencies of FDS. The proposed FDS can guide for design, reduce the wear of diamond, and improve processing quality.
{"title":"Dynamics modeling and analysis of feed drive system for a frame saw machine considering time-varying load","authors":"Depeng Sun, Jinsheng Zhang","doi":"10.1051/MECA/2021019","DOIUrl":"https://doi.org/10.1051/MECA/2021019","url":null,"abstract":"Frame saw machine is one of machine tools that is used to process dimension stone. The velocity fluctuation of traditional feed drive system (FDS) lead to excessive wear of diamond particles. The dynamic performance of the FDS has time-varying characteristics during the processing of stone with a large material removal rate. In this paper, a novel FDS was proposed. Firstly, the dynamic modeling of FDS was set up on account of lumped parameter method (LPM). Then the speed of the new FDS was compared with that of the traditional FDS. Finally, the frequency response characteristics of the system were solved by Lagrange and state space method. Results showed that the new FDS has a faster response feed and less velocity fluctuation. The natural frequency and the amplitude of acceleration increase with decreasing load. With the time-varying load, the range of the second-order natural frequency increased by 50 Hz, which was larger than that of the first-order. The modal test verified that the first two natural frequencies of the saw blade are within the range of the natural frequencies of FDS. The proposed FDS can guide for design, reduce the wear of diamond, and improve processing quality.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77212806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chiller plants are the most energy consuming system during summer season in residential, commercial and hospital buildings. The highly variable cooling demand of the buildings connected to a hybrid chiller plant included absorption and vapor compression chillers to achieve higher energy efficiencies is one of the important issues. Cooling load sharing strategies and apply the variable water flow system in chiller plant have a significant impact on energy consumption and consequently with more productivity and environmentally protected. This paper examines the behavior and pattern of energy consumption in a hybrid chiller plant that includes a combination of two air-cooled screw vapor compression and three single effect absorption chillers. In order to properly understand the pattern of energy consumption, an existing mechanical room in a hospital in Tehran has been studied for five months, and its energy consumption has been compared with the optimized model. The results indicate that the sequence of the chiller function and the way in which they are placed in the circuit during a partial load, is in highest importance in view point of energy saving also by Applying of variable water flow system for optimized chiller loading the more energy saving is achieved for hybrid absorption and vapor compression chiller plant.
{"title":"Variable flow and optimization of chiller loading effect on energy saving for screw vapor compression-single effect absorption hybrid chiller plant in hospital mechanical room ‒ case study: Tehran heart hospital","authors":"R. Boghosian, M. Mafi, M. H. Panjeshahi, A. Ataei","doi":"10.1051/MECA/2021006","DOIUrl":"https://doi.org/10.1051/MECA/2021006","url":null,"abstract":"Chiller plants are the most energy consuming system during summer season in residential, commercial and hospital buildings. The highly variable cooling demand of the buildings connected to a hybrid chiller plant included absorption and vapor compression chillers to achieve higher energy efficiencies is one of the important issues. Cooling load sharing strategies and apply the variable water flow system in chiller plant have a significant impact on energy consumption and consequently with more productivity and environmentally protected. This paper examines the behavior and pattern of energy consumption in a hybrid chiller plant that includes a combination of two air-cooled screw vapor compression and three single effect absorption chillers. In order to properly understand the pattern of energy consumption, an existing mechanical room in a hospital in Tehran has been studied for five months, and its energy consumption has been compared with the optimized model. The results indicate that the sequence of the chiller function and the way in which they are placed in the circuit during a partial load, is in highest importance in view point of energy saving also by Applying of variable water flow system for optimized chiller loading the more energy saving is achieved for hybrid absorption and vapor compression chiller plant.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86572709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To reduce the navigation control cost, this paper proposes a mechanical guidance control scheme that uses a cam-link mechanism as a steering control mechanism for an automated guided vehicle with a fixed driving path. According to the steering principle, a mathematical model of the steering system and the driving trajectory are established. By setting the boundary conditions, the vehicle trajectory is modeled using a quintic polynomial. The contour of the directional control cam is obtained based on the equation of the vehicle trajectory. Because errors occur in actual machining and assembly processes, errors will be classified based on their impact on the trajectory. The effects of various errors on the trajectory are quantitatively determined by using simulation methods with different parameters. Furthermore, an error compensation approach is designed to reduce the influence of the error on the trajectory directly or indirectly. Finally, experiment results illustrate that the adjustment accuracy of the proposed automated guided vehicle trajectory is 2 mm.
{"title":"Design and error compensation of active mechanically automated guided vehicle","authors":"Jianqiang Yan, Mi Li, Zhongxian Chen, Yihang Li","doi":"10.1051/MECA/2021011","DOIUrl":"https://doi.org/10.1051/MECA/2021011","url":null,"abstract":"To reduce the navigation control cost, this paper proposes a mechanical guidance control scheme that uses a cam-link mechanism as a steering control mechanism for an automated guided vehicle with a fixed driving path. According to the steering principle, a mathematical model of the steering system and the driving trajectory are established. By setting the boundary conditions, the vehicle trajectory is modeled using a quintic polynomial. The contour of the directional control cam is obtained based on the equation of the vehicle trajectory. Because errors occur in actual machining and assembly processes, errors will be classified based on their impact on the trajectory. The effects of various errors on the trajectory are quantitatively determined by using simulation methods with different parameters. Furthermore, an error compensation approach is designed to reduce the influence of the error on the trajectory directly or indirectly. Finally, experiment results illustrate that the adjustment accuracy of the proposed automated guided vehicle trajectory is 2 mm.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77157338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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