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A novel approach for NURBS interpolation through the integration of acc-jerk-continuous-based control method and look-ahead algorithm

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2017年第1-4期88卷 961-969页

作者： Liu Xinhua Peng Junquan Si Lei Wang Zhongbin China Univ Min & Technol Sch Mech & Elect Engn Xuzhou Peoples R China China Univ Min & Technol Sch Informat & Elect Engn Xuzhou Peoples R China

In order to reduce high chord errors and improve poor flexibility of interpolation, a novel approach for non-uniform rational B-spline (NURBS) interpolation through the integration of an acc-jerk-continuous-based control method and look-ahead algorithm is proposed. At first, the principles of NURBS curve interpolation and implementation are described. Then, modules of the proposed algorithm, including the feed rate planning and acc-jerk-continuous modules, are established. In the feed rate planning module, sharp corners are detected and the curve is split into some NURBS blocks according to sharp corners. The knot parameter and restrict feed rate at the sharp corners are obtained as well as the length of each block is calculated. In the acc-jerk-continuous control module, information including the knot parameter, arc length, and start and end feed rates are handled to plan an acc-jerk-continuous trajectory. Finally, simulation with one free-form NURBS curve is conducted and comparison with the S-shaped scheduling algorithm is carried out to verify the feasibility and applicability of the proposed algorithm.

关键词： NURBS interpolation Acc-jerk-continuous-based control method look-ahead algorithm

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Investigation on path optimization and look-ahead speed control algorithm during numerical control grinding of dentures of glass ceramics

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2021年第7-8期113卷 1899-1913页

作者： Zhang, Yong Wu, Tao Li, Chen Liu, Jianxun Wang, Yongfei Harbin Inst Technol Sch Mechatron Engn Harbin 150001 Peoples R China

The processing efficiency of dentures is generally quite low due to the complex profile form and high brittleness of the dentures. However, there is little research for efficient path optimization and look-ahead speed control algorithm in denture machining field, which hinders the improvement of the machining efficiency and denture quality. In this work, an optimization method for both straight transition and curve paths was proposed, and look-ahead speed control algorithms for different machining paths were designed. The anomalous points were deleted according to the preprocessing algorithm before the path optimization. The straight transition path and curve path were fitted by the quasi-parabola model and cubic B-spline curve, respectively. The error between the optimized path and original path was analyzed, and the results demonstrated that the path optimization methods were reliable. A look-ahead speed control model based on S-type speed control was proposed, and the boundary conditions for different paths were calculated. The simulated and experimental results indicated that optimized algorithm significantly improved the machining efficiency and reduced the vibration of the machine tool. The accuracy and surface roughness of the denture processed using the optimized algorithm met the medical standard. This work can provide a theoretical guidance for high-efficiency and precision machining of dentures of glass ceramics.

关键词： Grinding Denture machining Path optimization B-spline curve look-ahead algorithm Glass ceramics

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Application of the Five-phase S-curve Velocity Model on FDM Three-dimensional Printer 5

Application of the Five-phase S-curve Velocity Model on FDM ...

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IEEE 5th Information Technology and Mechatronics Engineering Conference (ITOEC)

作者： Yu, Ke Zhang, Zhisheng Zhou, Zhiting Dai, Min Southeast Univ Sch Mech Engn Nanjing Jiangsu Peoples R China

ISBN: (纸本)9781728143231;9781728143224

The essence of the FDM (Fused Deposition Modeling) three-dimensional printing control technology is that the extrusion nozzle completes point-to-point motions by stepper motors according to a specified trajectory from G-codes. In the implementation of the G-code feeding, the stepper motor plays a very important role, not only providing power for the mechanical structure that drives the movement of the extrusion nozzle, but also directly participating in the control of the nozzle position. Allowing the speed of stepper motors to undergo a low-to-high acceleration process is a necessary process in the actual application environment, and the speed planning strategy will directly influence the molding quality and efficiency of the 3D model. This paper introduces the five-phase S-curve velocity model to control and plan the frequency of stepper motors and how to apply the model on the environment of 3D printer. Furthermore, the look-ahead algorithm is introduced to make the speed planning of multiple G-code paths more efficient. The experiment result proves the reduce on the effects of flexible impacts and the improvements on the surface quality of finished 3D models.

关键词： FDM 3D printer S-curve velocity model look-ahead algorithm

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A new mixed integer program and extended look-ahead heuristic algorithm for the block relocation problem

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2013年第1期231卷 120-130页

作者： Petering, Matthew E. H. Hussein, Mazen I. Univ Wisconsin Dept Ind & Mfg Engn Milwaukee WI 53201 USA

This paper considers the block relocation problem (BRP), in which a set of identically-sized items is to be retrieved from a set of last-in-first-out (LIFO) stacks in a specific order using the fewest number of moves. The problem is encountered in the maritime container shipping industry and other industries where inventory is stored in stacks. After surveying the work done on the BRP, we introduce "BRP-III"-a new mathematical formulation for the BRP and show that it has considerably fewer decision variables and better runtime performance than the other formulation in the literature. We then introduce a new look-ahead algorithm (LA-N) that is an extension of the algorithms from the literature and show that the new algorithm generally obtains better solutions than the other algorithms and has minimal CPU runtime. (C) 2013 Elsevier B.V. All rights reserved.

关键词： Logistics Block relocation problem Seaport container terminal Mixed integer programming look-ahead algorithm

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A NEW look-ahead algorithm TO IMPROVE THE PERFORMANCE OF OMEGA NETWORKS

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MATHEMATICAL & COMPUTATIONAL APPLICATIONS 2010年第2期15卷 156-165页

作者： Almazyad, Abdulaziz S. King Saud Univ Coll Comp & Informat Sci Dept Comp Engn Riyadh 11543 Saudi Arabia

In this paper, we concentrate on the internal blocking problem related to Omega Network which is a type of Multistage Interconnection Networks (MINs). We introduce a new algorithm to alleviate the internal blocking problem, the function of this look-ahead algorithm is to decide which packet to block in case of internal blocking. The performance results indicate that the introduced algorithm decreases the internal blocking problem significantly. Since the computations involved in the introduced algorithm are so little, it can be implemented in real time effectively.

关键词： MINs Omega networks Internal blocking look-ahead algorithm

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Entropy-based dispatching for automatic guided vehicles

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INTERNATIONAL JOURNAL OF PRODUCTION RESEARCH 2014年第11期52卷 3303-3316页

作者： Marvizadeh, S. Zamiri Choobineh, F. F. Univ Nebraska Dept Ind & Management Syst Engn Lincoln NE 68588 USA Univ Nebraska Dept Elect Engn Lincoln NE 68588 USA

A highly desirable performance of a factory is achieving a laminar flow of parts within the factory. This paper proposes new automatic guided vehicle (AGV) dispatching algorithms with the objective of load balancing among the factory work centres by choosing the dispatch decision, which contributes the most to the laminar flow of the factory. The Kullback-Leibler directed divergence measure is applied to compare a dispatch decision with a balanced factory. Simulation experiments are conducted to study the effectiveness of suggested algorithms.

关键词： directed divergence entropy balanced factory look-ahead algorithm vehicle dispatching

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An interpolation method for the open CNC system based on EPM

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2013年第1-4期69卷 405-416页

作者： Jin, Yu-an He, Yong Fu, Jian-zhong Chen, Zi-Chen Zhejiang Univ State Key Lab Fluid Power Transmiss & Control Hangzhou 310027 Peoples R China

A typical open computer numerical control (CNC) system should own the capability of being redeveloped easily and effectively, and any improvements of interpolation algorithm or machining technique could be put into practice by users conveniently. However, this is not always available in the current open CNC systems. To solve this problem, an interpolation method based on external profile mode (EPM) is introduced to improve the universality and the performance of an open CNC system in this paper. The method is realized with a rough interpolation in the PC host and a fine interpolation in the slave motion controller. With this method, various interpolation algorithms can be easily realized in the rough interpolation when machining complex contours. Meanwhile, the machining parameters during each interpolation cycle can be wholly determined by the host, so a real-time adjustment of machining parameters can be accomplished during the interpolation. The working principal of EPM is presented in this paper, and the realization of interpolation algorithms with the proposed method is described. A look-ahead algorithm for determining the machining parameters of each segment is implemented based on the length of segments in the rough interpolation. An acceleration/deceleration strategy with confined jounce is proposed in the look-ahead algorithm. The experimental results of specific profile interpolation show that the interpolation method based on EPM can make the open CNC system more universality and high performance.

关键词： CNC External profile mode Line segments look-ahead algorithm

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Adaptive intelligent control of vehicle air conditioning system

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APPLIED THERMAL ENGINEERING 2013年第1-2期51卷 1154-1161页

作者： Khayyam, Hamid Deakin Univ Sch Engn Geelong Vic 3216 Australia Deakin Univ Melbourne Inst Business & Technol Geelong Vic 3216 Australia

Efficient performance of a vehicle Air Conditioning (AC) can be affected by uncertain factors such as road conditions, environmental conditions and driver behaviour. Recent study shows that prediction of road power demands (look-ahead) for AC system can provide the optimum comfort temperature with air quality as well as a reduction of energy consumption. The new energy management system features comprise recent research over and above making adaptive the intelligent AC controller to ensure proper operation under different road load conditions. For making an adaptive fuzzy controller, the following important issues must be considered: the size of the membership functions of the fuzzy sets, the position of the membership functions, the rule weights and/or the link values. The adaptive intelligent air conditioning system was able to control the operation of AC, blower, fresh-air and recirculation gates for providing the desired comfort temperature and indoor air quality under various environment conditions. The simulation results of the adaptive intelligent air conditioning system demonstrate around 1% more energy saving compared to fuzzy air conditioning enhanced with look-ahead system. (C) 2012 Elsevier Ltd. All rights reserved.

关键词： Energy management Adaptive air conditioning system look-ahead algorithm Intelligent control Adaptive fuzzy control

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Research on Acceleration/Deceleration in NURBS curve interpolation

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2nd International Conference on Mechanical Engineering, Materials and Energy (ICMEME 2012)

作者： Gao, Sumei Mu, Fuyuan Zheng, Liming Jinling Inst Technol Nanjing Jiangsu Peoples R China

ISBN: (纸本)9783037855928

A non-uniform rational B-spline (NURBS) parametric curve interpolation and S-shape acceleration/deceleration (ACC/DEC) for CNC machine tool were studied. In the proposed algorithm, the commanded velocity is maintained at most of the time and adaptively reduced in large curvature areas to meet the demand of the machining accuracy requirement, while at the same time, a S-shape look ahead algorithm is proposed to limit the acceleration and jerk values within the machine's capabilities during the whole interpolation process. It reduces mechanical shock to the machine tools. The real time performance of this interpolator is also measured to demonstrate its practical application. A NURBS curve interpolation experiments is provided to verify the feasibility and advantages of the proposed algorithm.

关键词： NURBS S-shape acceleration/deceleration look-ahead algorithm CNC interpolate

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look-ahead algorithm FOR VELOCITY CONTROL BASED ON PARAMETERIZED CURVE INTERPOLATOR

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Chinese Journal of Mechanical Engineering 2008年第2期21卷 23-26页

作者： REN Kun FU Jianzhong CHEN Zichen College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China

To avoid suffering gouge and transient overshooting in high speed cutting machining, a novel parametefized curve interpolator model with velocity look-ahead algorithm is proposed. Based on a prearrangement step interpolation algorithm for parameterized curves and considering high curvature points, parameterized curve tool path is divided into acceleration segments and deceleration segments by look-ahead algorithm. Under condition of characteristics of acceleration and deceleration stored in control system, deceleration before high curvature points and acceleration after high curvature points are realized in real-time in high speed cutting machining. Based on new parameterized curve interpolator model with velocity look-ahead algorithm, a real cubic spline is machined simulativly. The simulation results show that velocity look-ahead algorithm improves velocity changing more smoothly.

关键词： High speed cutting machining Parameterized curve interpolator look-ahead algorithm

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