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Real-Time Control for CPS of Digital Airplane Assembly with Robust H-Infinity Theory

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Tsinghua Science and Technology 2015年第4期20卷 376-384页

作者： Hui Li linxuan zhang Tianyuan Xiao Jietao Dong State CIMS Engineering Research Cente at Tsinghua University

This study introduces a real-time controller design method under the effects of network time delay and external disturbance. The study first introduces the digital, virtual, intelligent trend of airplane assembly and reveals the status and problems of digital airplane assembly studies. The Cyber-Physical System （CPS） structure is then proposed for digital airplane assembly, and the real-time control issues are discussed. Then, the question of real- time control undertaken by a parallel robot is simplified to a control question with bounded time delay and complex interference, and a mathematical description is presented. Next, a robust Hoo controller with a disturbance degree of decay 7 is designed according to the mathematical description. Finally, a simulation is conducted. All of the experiment results show the feasibility of the above proposed methods.

关键词： cyber physical system network time delay robust H-infinity control linear matrix inequality

Synergic Motion Trajectory Planning for Airplane Docking Based on6PURU Parallel Mechanism

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Tsinghua Science and Technology 2015年第2期20卷 188-199页

作者： Hui Li linxuan zhang Tianyuan Xiao Jietao Dong State CIMS Engineering Research Center at Tsinghua University

Motion planning issues encountered in assembling airplanes by employing the 6PURU parallel mechanism are analyzed in this paper. A sine curve of the change rate of acceleration, which is called as jerk in the following text, is proposed for uniaxial flexible acceleration and deceleration planning based on the optimal time and velocity and acceleration constraints. Compared with other curves, the proposed curve can realize a continuous n-order derivative and the smooth change of the speed and acceleration. The method is computational^y simple and suitable for programming. In addition, a multiaxial coordinated movement scheme is proposed. The motion trajectory is no longer simply split into many single-direction trajectories nor are all single-direction planning trajectories combined directly. The multiaxial coordinated movement scheme aims to achieve synergic movement in multiple directions to ensure smoothness of the movement in the event of a kinematic error when maintaining a stable value. If the movement fails to achieve this goal, driving force mutations will deteriorate the effect of synergic movement. A physical model of the parallel mechanism is developed in simMechanics, and a holistic system model is completed in SIMULINK. The feasibility of the new planning algorithm is simulated and tested, and then, the multiaxial synergic movement planning method is proposed and verified.

关键词： assembly simulation motion trajectory planning parallel mechanism simMechanics

Adaptive scheduling method for dynamic robotic cell based on pattern classification algorithm

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International Journal of Modeling, Simulation, and Scientific Computing 2018年第5期9卷 74-91页

作者： Chuyuan Wang linxuan zhang Chongdang Liu National CIMS Engineering Research Center Tsinghua University Beijing 100084P.R.China

In order to deal with the dynamic production environment with frequent fluctuation of processing time,robotic cell needs an efficient scheduling strategy which meets the real-time *** paper proposes an adaptive scheduling method based on pattern classification algorithm to guide the online scheduling *** method obtains the scheduling knowledge of manufacturing system from the production data and establishes an adaptive scheduler,which can adjust the scheduling rules according to the current production *** the process of establishing scheduler,how to choose essential attributes is the main *** order to solve the low performance and low efficiency problem of embedded feature selection method,based on the application of Extreme Gradient Boosting model(XGBoost)to obtain the adaptive scheduler,an improved hybrid optimization algorithm which integrates Gini impurity of XGBoost model into Particle Swarm Optimization(PSO)is employed to acquire the optimal subset of *** results based on simulated robotic cell system show that the proposed PSO-XGBoost algorithm outperforms existing pattern classification algorithms and the newly learned adaptive model can improve the basic dispatching *** the same time,it can meet the demand of real-time scheduling.

关键词： Robotic cell adaptive scheduling simulation particle swarm optimization extreme gradient boosting.

Data fusion and simulation-based planning and control in cyber physical system for digital assembly of aeroplane

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第3期6卷 66-84页

作者： Hui Li linxuan zhang Tianyuan Xiao Jietao Dong State CIMS Engineering Research Center at Tsinghua University Main Building Room 604 Beijing 100084P.R.China State CIMS Engineering Research Center at Tsinghua University Main Building Room 601 Beijing 100084P.R.China State CIMS Engineering Research Center at Tsinghua University Main Building Room 619 Beijing 100084P.R.China

This paper introduces a CPS application for intelligent aeroplane *** first,the CPS structure is presented,which acquires the characteristics of general CPS and enables“simulation-based planning and control”to achieve high level intelligent *** the paper puts forward data fusion estimation algorithm under synchronous and asynchronous sampling,*** experiment shows that global optimal distributed fusion estimation under synchronized sampling proves to be closer to the actual value compared with ordinary weighted estimation,and multi-scale distributed fusion estimation algorithm of wavelet under asynchronous sampling does not need time registration,it can also directly link to data,and the error is *** paper presents hybrid control strategy under the circumstance of joint action of the inner and outer loop to address the problems caused by the less controllable feature of the parallel mechanism when undertaking online process simulation and control.A robust adaptive sliding mode controller is designed based on disturbance observer to restrain inner interference and maintain *** the same time,an outer collaborative trajectory planning is also *** the experiment results show the feasibility of above proposed methods.

关键词： Intelligent aeroplane assembly cyber physical system multi-sensor data fusion simulation-based control disturbance observer robust adaptive sliding mode controller

A dynamic delivery strategy for material handling in mixed-model assembly lines using decentralized supermarkets

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第4期6卷 73-91页

作者： Jietao Dong linxuan zhang Tianyuan Xiao Hui Li National CIMS Engineering Research Center Tsinghua University Beijing 100084 P.R.China

Material handling has become one of the major challenges in modern production ***,this paper intends to investigate the part delivery of mixedmodel assembly lines with decentralized supermarkets and tow ***,uncertain exception disturbances,including tow train failures and adjustments of the production sequence,are also *** solve this problem,a heuristic-based dynamic delivery strategy is proposed,which dynamically schedules the route,departure time,quantities and types of loaded parts for each *** evaluate the performance of this strategy,it is used to solve an instance in comparison with the periodic delivery strategy,experimental results are reported and their performances are compared under different ***,a multi-scenario analysis is employed to determinate the long-term decisions,including the number of tow trains and the route ***,the critical storage is suggested to be set for each station to avoid part starvation resulting from disturbances,and its effect on the delivery performance is investigated.

关键词： Mixed-model assembly lines dynamic part delivery supermarket tow train critical storage.

RESEARCH ON PRODUCT INNOVATION DESIGN IN VIRTUAL PRODUCT DEVELOPMENT

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Chinese Journal of Mechanical Engineering 2002年第4期15卷 353-359页

作者： Wu Qunbo zhang linxuan Xiao Tianyuan Long Xinghai State CIMS Engineering Research Center, Tsinghua University, Beijing 100084, China Tsinghua University State CIMS Engineering Research Center 北京 100084

An integrated template of virtual product development alters primarilysequential tradition mode of product life cycle. The template integrates all processes of productdevelopment using digital modem. An environment of virtual product development provides productdevelopment environment of integration, communion, network, concurrent and collaboration. Combiningdevelopment of new rapier loom, an innovated design process is researched in virtual productdevelopment, which consists three portions: constructing an integration development environment,innovation design and manufacturing simulation. The innovated design process realizes reversedesign, mechanism concept design, structural design and analysis, performance analysis andmanufacturing process simulation of virtual product, which can enhance greatly product performanceand reduce cost and development cycle of new product.

关键词： virtual product development innovation design product data management

Approach of hybrid GA for multi-objective job-shop scheduling

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International Journal of Modeling, Simulation, and Scientific Computing 2016年第4期7卷 58-67页

作者： Qiaofeng Meng linxuan zhang Yushun Fan State CIMS Engineering Research Center at Tsinghua University Beijing 100084 P.R.China

In recent years,scholars have made many research results on job-shop scheduling(JSP)problem,especially in single objective such as the maximum completion *** most of the actual system scheduling problems are more than one ***,the research of multi-objective scheduling problem is very important and *** this paper,we proposed a multi-objective scheduling model which adopts weighted sum method to optimize two important indexes(makespan and total flow time).Genetic algorithm(GA)has diversified global search ability,while simulated annealing(SA)combined with tabu search(TS)have intensified capabilities in local neighborhood *** overcome the drawback of the GA,we proposed a new hybrid GA(NewHGA)which produces initial solutions by GA firstly,and then take SA operator incorporate TS operator to search in the local *** adding the novel local search strategy,the diversity of solutions will be improved greatly so that it can ensure the algorithm jump out of the local optimal *** test this algorithm using the benchmark instances of different sizes taken from the OR-Library,and the results show that the algorithm is efficient than another hybrid algorithm.

关键词： Job shop multiple objectives weighted sum method the maximum completion time total flow time

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DFA中零件对称度的自动识别算法

清华大学学报（自然科学版） 2008年第4期48卷 490-494页

作者：郑赟张林鍹肖田元清华大学自动化系北京100084

零件对称度是面向装配的设计(DFA)中评价装配性能的重要指标之一,对称度的自动识别能促进DFA与计算机辅助设计(CAD)系统的集成。针对已有识别算法效率较低的现状,给出了一种对称度自动识别的算法,该算法分为2个阶段,第一阶段通过旋转零... 详细信息

零件对称度是面向装配的设计(DFA)中评价装配性能的重要指标之一,对称度的自动识别能促进DFA与计算机辅助设计(CAD)系统的集成。针对已有识别算法效率较低的现状,给出了一种对称度自动识别的算法,该算法分为2个阶段,第一阶段通过旋转零件并比较其空间包容盒来计算对称度的范围,第二阶段利用射线追踪法进一步计算对称度的精确值,大部分非对称零件在第一阶段就可以结束计算,使得算法平均效率较高。基于CAD系统P ro/Engineer二次开发实现了该算法,并通过一组实例验证了算法的正确性和实用性。

关键词：计算机辅助设计(CAD) 面向装配的设计(DFA) 对称度空间包容盒射线追踪

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基于改进动态窗口的车库AGV路径规划及仿真

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系统仿真学报 2024年第10期36卷 2265-2276页

作者：马宗方张琳旋宋琳王嘉西安建筑科技大学信息与控制工程学院陕西西安710055

针对在智能车库环境下,移动机器人(AGV)在作业过程中面临着复杂路径环境下的路径规划和实时避障,提出一种改进的蚁群算法与动态窗口法(DWA)相结合的混合算法。在全局规划中引入自适应调整信息素挥发系数,融合角度参数建立车库方向信息... 详细信息

针对在智能车库环境下,移动机器人(AGV)在作业过程中面临着复杂路径环境下的路径规划和实时避障,提出一种改进的蚁群算法与动态窗口法(DWA)相结合的混合算法。在全局规划中引入自适应调整信息素挥发系数,融合角度参数建立车库方向信息素矩阵,增大目标点引导能力,扩大蚂蚁的方向选择性;在局部规划中设计基于椭圆方程的障碍物距离评价子函数的改进动态窗口法,并提取改进蚁群算法的全局关键节点作为新增的路径评价子函数,在全局路径的约束下,保持动态规划的最优性。仿真结果表明:改进算法较传统算法能够较好地应对突发的动静态障碍物,更符合AGV实际作业过程中在多重环境因素的影响下的动态规划要求。

关键词：车库AGV 蚁群算法动态窗口法动静态避障路径规划椭圆方程