Intelligent production planning for complex garment manufacturing

Apparel production is characterised by labour-intensive manual operations, frequent style changes, seasonal demand and shortening production lead times. With fierce competition worldwide, many manufacturers are switching their production from mass mode to lean mode to shorten their response time to changes. In a complex mixed mode production environment, it is very important to allocate job orders to suitable production lines so as to ensure the effective utilization of production resources and on-time completion of all job orders. In this paper, planning algorithms are proposed for automatic job allocations based on group technology and genetic algorithms. For genetic algorithms based intelligent planning algorithms, single-run and multiple-run genetic algorithms are suggested. Real production data are used to validate the proposed method. The proposed algorithms has been shown being able to substantially improve planning quality. These planning algorithms are currently used by apparel manufacturers in Hong Kong as part of their routine planning operations.     

智能仿生算法在移动机器人路径规划优化中的应用综述

随着移动机器人应用领域的扩大和工作环境的复杂化,传统路径规划算法因其自身局限性变得难以满足人们的要求。近年来,智能仿生算法因其群集智慧和生物择优特性而被广泛应用于移动机器人路径规划优化中。首先,按照智能仿生算法仿生机制的来源,对应用于路径规划优化中的智能仿生算法进行了分类。然后,按照不同的类别,系统的叙述了各种新型智能仿生算法在路径规划优化中取得的最新研究成果,总结了路径规划优化过程中存在的问题以及解决方案,并对算法在路径规划优化中的性能进行了比较分析。最后对智能仿生算法在路径规划优化中的研究方向进行了探讨。     

机器人运动规划方法的研究

针对路径规划以及碰撞检测这一研究的重点问题,提出了G-空间法、人工势力场法、遗传算法等。序列规划问题一般转化为旅行商问题来求解。在综合现有序列规划和路径规划方法的基础上,提出两种机器人运动规划算法：基于任意路径的运动规划算法和基于直线路径的运动规划算法,思路简单,能对各种机器人工程任务进行运动规划。     

Coverage for robotics – A survey of recent results

This paper surveys recent results in coverage path planning, a new path planning approach that determines a path for a robot to pass over all points in its free space. Unlike conventional point-to-point path planning, coverage path planning enables applications such as robotic de-mining, snow removal, lawn mowing, car-body painting, machine milling, etc. This paper will focus on coverage path planning algorithms for mobile robots constrained to operate in the plane. These algorithms can be classified as either heuristic or complete. It is our conjecture that most complete algorithms use an exact cellular decomposition, either explicitly or implicitly, to achieve coverage. Therefore, this paper organizes the coverage algorithms into four categories: heuristic, approximate, partial-approximate and exact cellular decompositions. The final section describes some provably complete multi-robot coverage algorithms.     

移动机器人路径规划研究现状及展望

移动机器人路径规划技术是机器人研究领域中的核心技术之一。通过对全局路径规划和局部路径规划中各种方法的分析,指出了各种方法的优点和不足以及改进的办法,并对移动机器人路径规划技术的发展趋势进行了展望。     

移动机器人路径规划算法的研究综述

路径规划是移动机器人的热门研究之一,是实现机器人自主导航的关键技术。针对移动机器人路径规划的算法进行研究,以了解不同条件下路径规划算法的发展与应用,系统性地总结了路径规划的研究现状和发展。针对移动机器人路径规划的特点,将其划分为智能搜索算法、基于人工智能算法、基于几何模型算法和用于局部避障算法。基于上述分类,介绍了近年来具有代表性的研究成果,重点分析各类规划算法的优缺点,对移动机器人路径规划的未来发展趋势进行展望,为移动机器人路径规划研究提供一定的思路。     

工业机器人运动规划研究进展

由于工业机器人构型空间和工作环境的复杂性,传统运动规划算法难以在有限时间内进行路径求解,如何提高算法的规划效率与最优性成为研究热点。本文跟踪目前工业机器人运动规划算法的发展现状,针对主流随机采样算法的原理与发展脉络进行了细致分析与总结。在此基础上,详细阐述了基于强化学习的随机采样算法,该方法引入了规划学习机制,在保证求解速度的同时,还能不断提高求解质量。同时对当前运动规划算法存在的一些不足提出了建议与展望。     

Cognition, tasks and planning: supporting the planning of shunting operations at the Netherlands Railways

One of the issues in planning research and planning practice are their apparent incompatibility. Various fields study aspects of planning, but too little is jointly used in practice. Starting from the human planner as a cognitive system, we elaborate the mixed initiative approach, in which we combine three fields: cognitive aspects of the task of the human planner, computer support, and algorithms. In this article, we argue that algorithms should be created for planners’ subtasks rather than for planning problems. We demonstrate this in a prototype that we developed for a shunting planning project we are involved in at the Netherlands Railways [Nederlandse Spoorwegen (NS)]. In this project, a task analysis resulted in a planning support system with bottom up designed scheduling algorithms.     

基于预测信息的时间依赖网络路径规划算法

分析最小时间规划算法,针对算法在应用上存在的不足,在研究SPFA静态规划算法的基础上,结合该规划算法的优点,提出一种改进的最小时间路径规划算法。实例验证结果表明,该算法能够提供实时、高效、预测性强的规划路径,在城市交通中较好地满足用户的需求。     

An Adaptive Rapidly-Exploring Random Tree

Sampling-based planning algorithms play an important role in high degree-of-freedom motion planning(MP)problems,in which rapidly-exploring random tree(RRT)and the faster bidirectional RRT(named RRT-Connect)algorithms have achieved good results in many planning tasks.However,sampling-based methods have the inherent defect of having difficultly in solving planning problems with narrow passages.Therefore,several algorithms have been proposed to overcome these drawbacks.As one of the improved algorithms,Rapidlyexploring random vines(RRV)can achieve better results,but it may perform worse in cluttered environments and has a certain environmental selectivity.In this paper,we present a new improved planning method based on RRT-Connect and RRV,named adaptive RRT-Connect(ARRT-Connect),which deals well with the narrow passage environments while retaining the ability of RRT algorithms to plan paths in other environments.The proposed planner is shown to be adaptable to a variety of environments and can accomplish path planning in a short time.     

Novel integrated optimization algorithm for trajectory planning of robot manipulators based on integrated evolutionary programming

Optimal trajectory plarmmg for robot manipulators plays an important role in implementing the high productivity for robots. The performance indexes used in optimal trajectory planning are classified into two roam categories:optimum traveling time and optimum mechanical energy of the actuators. The current trajectory planning algorithms are designed based on one of the above two performance indexes. So far, there have been few planning algorithms designed to satisfy two performance indexes simultaneously. On the other hand, some deficiencies arise in the existing integrated optimization algorithms of trajectory planning.In order to overcome those deficiencies, the integrated optimization algorithms of trajectory planning are presented based on the complete analysis for trajectory planning of robot manipulators. In the algorithm, two object functiom are designed based on the specific weight coefficient method and “ideal point” strategy. Moreover, based on the features of optimization problem, the intensified evolutionary programming is proposed to solve the corresponding optimization model. Especially, for the Stanford Robot, the high-quality solutions are found at a lower cost.     

批量生产企业的车间计划调度算法研究与应用

分析了批量生产企业车间计划调度问题的资源、任务和活动,讨论了车间计划调度的约束及其实现,给出了基于复合规则的计划调度算法,在西安航空发动机公司32车间的计划管理系统中得到了应用。     

On the importance of breaking ties in the relaxed plan heuristic

The relaxed plan heuristic is a domain-independent heuristic for automated planning that computes an estimate of the cost for achieving the goals from a given state. This heuristic is based on the idea of solving a relaxed version of the planning task. Due to the great size of the state space, most heuristic search algorithms in planning suffer from scalability problems. These algorithms have to evaluate a great amount of states, and the time devoted to heuristic evaluations is one of the causes of the scalability problems. We argue that one way to lighten this problem is breaking ties in the heuristic value using additional information computed during the relaxed plan construction. We add a complementary value to the heuristic, allowing algorithms to discriminate between states with relaxed plans of the same length but with a different difficulty. The experimental evaluation in some planning benchmarks shows that the modification to the original heuristic can reduce the number of evaluated nodes for the most common algorithms used in heuristic planning.     

Model-driven engineering of planning and optimisation algorithms for pervasive computing environments

This paper presents a model-driven approach to developing pervasive computing applications that exploits design-time information to support the engineering of planning and optimisation algorithms that reflect the presence of uncertainty, dynamism and complexity in the application domain. In particular, the task of generating code to implement planning and optimisation algorithms in pervasive computing domains is addressed.We present a layered domain model that provides a set of object-oriented specifications for modelling physical and sensor/actuator infrastructure and state-space information. Our model-driven engineering approach is implemented in two transformation algorithms. The initial transformation parses the domain model and generates a planning model for the application being developed that encodes an application’s states, actions and rewards. The second transformation parses the planning model and selects and seeds a planning or optimisation algorithm for use in the application.We present an empirical evaluation of the impact of our approach on the development effort associated with two pervasive computing applications from the Intelligent Transportation Systems (ITS) domain, and provide a quantitative evaluation of the performance of the algorithms generated by the transformations.     

移动机器人路径规划算法综述

路径规划算法是实现移动机器人自主导航的关键技术。针对移动机器人路径规划技术进行研究,分析各算法的实现机制与原理,并系统性的总结了主流路径规划算法研究现状。根据移动机器人路径规划算法的特点,将路径规划算法分为：传统规划算法、智能规划算法、基于采样的规划算法。基于以上分类,分述近年来的主要研究成果,重点分析各类算法的优缺点。针对移动机器人路径规划算法研究现状,对其未来研究方向进行展望,为移动机器人路径规划大发展提供一定的思路。     

Dynamics and Motion Planning of Trident Snake Robot

The trident snake robot is a mechanical device that serves as a demanding testbed for motion planning and control algorithms of constrained non-holonomic systems. This paper provides the equations of motion and addresses the motion planning problem of the trident snake with dynamics, equipped with either active joints (undulatory locomotion) or active wheels (wheeled locomotion). Thanks to a partial feedback linearization of the dynamics model, the motion planning problem basically reduces to a constrained kinematic motion planning. Two kinds of constraints have been taken into account, ensuring the regularity of the feedback and the collision avoidance between the robot’s arms and body. Following the guidelines of the endogenous configuration space approach, two Jacobian motion planning algorithms have been designed: the singularity robust Jacobian algorithm and the imbalanced Jacobian algorithm. Performance of these algorithms have been illustrated by computer simulations.     

面向无人机集群路径规划的智能优化算法综述

在电–气–热互联系统(EGHS)的联合优化愈受关注的背景下, 提出一种电–气–热互联系统分布式优化调度 框架. 首先, 以系统供能成本最小建立同时考虑气网及热网动态特性的日前调度模型. 其次, 针对电–气–热互联系 统含电、气、热3个子系统在分布式运算属三区(3-Block)优化问题因而难以利用常规分布式算法得到收敛解的问题, 提出基于交替方向乘子法(ADMM)的改进算法, 即强制平等的ADMM算法. 所提算法框架为内外层协调凸分布框 架, 外层为罚凸凹算法(PCCP), 内层为ADMM–FE算法. 此算法框架中, 外层优化利用罚凸凹过程将非凸气流方程 凸化为逐次迭代的二阶锥约束, 内层ADMM–FE算法求解外层凸化后的模型以得到收敛解. 最后, 通过算例仿真分 析对比了所提算法与传统ADMM算法及集中式优化算法的计算结果, 所得结果验证了所提模型以及优化算法框架 的有效性.     

A fast two-stage ACO algorithm for robotic path planning

Ant colony optimization (ACO) algorithms are often used in robotic path planning; however, the algorithms have two inherent problems. On one hand, the distance elicitation function and transfer function are usually used to improve the ACO algorithms, whereas, the two indexes often fail to balance between algorithm efficiency and optimization effect; On the other hand, the algorithms are heavily affected by environmental complexity. Based on the scent pervasion principle, a fast two-stage ACO algorithm is proposed in this paper, which overcomes the inherent problems of traditional ACO algorithms. The basic idea is to split the heuristic search into two stages: preprocess stage and path planning stage. In the preprocess stage, the scent information is broadcasted to the whole map and then ants do path planning under the direction of scent information. The algorithm is tested in maps of various complexities and compared with different algorithms. The results show the good performance and convergence speed of the proposed algorithm, even the high grid resolution does not affect the quality of the path found.     

关节型工业机器人轨迹规划研究综述

关节型工业机器人凭借其良好的灵活性和高效率的工作模式被广泛地应用于现代工业自动化生产之中,例如搬运、码垛、焊接、切割等。轨迹规划是工业机器人运动控制的基础研究领域,决定着其作业效率和运动性能。工业机器人的轨迹规划是指综合考虑作业需求和机器人性能,在笛卡尔空间或关节空间内得出指导机器人末端执行器运动的轨迹。阐述了工业机器人轨迹规划的概念及其分类,就各个领域的轨迹规划算法进行了全面综述,包括基本轨迹规划和最优轨迹规划,指出了各类轨迹规划算法中所存在的问题和未来的发展方向。     

Heuristic approaches in robot path planning: A survey

Autonomous navigation of a robot is a promising research domain due to its extensive applications. The navigation consists of four essential requirements known as perception, localization, cognition and path planning, and motion control in which path planning is the most important and interesting part. The proposed path planning techniques are classified into two main categories: classical methods and heuristic methods. The classical methods consist of cell decomposition, potential field method, subgoal network and road map. The approaches are simple; however, they commonly consume expensive computation and may possibly fail when the robot confronts with uncertainty. This survey concentrates on heuristic-based algorithms in robot path planning which are comprised of neural network, fuzzy logic, nature-inspired algorithms and hybrid algorithms. In addition, potential field method is also considered due to the good results. The strengths and drawbacks of each algorithm are discussed and future outline is provided.