基于蚁群优化算法的目标拆卸序列规划

为了能够以较高的效率求解出产品中目标零件的拆卸方案,基于产品中零件间的拆卸优先约束关系,提出并建立目标零件的拆卸层次信息图模型,将目标零件的拆卸序列规划问题转化为对该图模型中具备最优值的路径的搜索和寻优问题.同时,提出一种改进蚁群优化算法,以实现对目标零件拆卸层次信息图的构建和对拆卸方案的搜索与寻优.最后通过实例验证了该方法的可行性和计算效率.     

基于蚁群算法的产品拆卸序列规划方法

拆卸是回收的前提,为了得到最大的回收效益,对拆卸序列进行规划,得到最优的拆卸序列.根据拆卸的特点构建适合计算和优化的产品拆卸混合图模型,该模型描述了零部件之间的连接关系和优先关系.然后通过几何推理方法产生所有可行的拆卸序列,建立目标函数并构建适合拆卸序列规划的蚁群算法:设计了满足连接关系和优先关系的可拆卸零件搜索空间,得到最优或接近最优的拆卸序列.最后通过实例验证了该方法的实用性和可行性.     

模糊推理Petri网及其在产品拆卸序列决策中的应用

为了在产品拆卸序列决策时,简化拆卸路径的分析难度,提出一种以模糊推理Petri网为工具的产品拆卸序列决策模型.采用将模糊推理Petri网与矩阵运算相结合的形式化推理算法,对所提出的决策算法进行了论述.实例应用结果表明,此模型在产品拆卸过程规划中具有很强的并行处理能力,可以根据产品在拆卸过程中零部件的最新信息对每一步操作作出适时的智能化决策,从而实现将产品中若干零件作为子装配体进行拆卸的自动聚类识别,减少了产品拆卸的复杂性.     

Web服务自动化测试技术

赋时Petri网为装配序列规划提供了有效的建模方法,但其在求解最优装配序列时受到组合复杂性的严重制约。零压缩二叉决策图(ZBDD)是处理大规模组合集合和0-1稀疏向量的一种有效符号技术,能够有效缓解组合爆炸问题。将赋时Petri网与ZBDD结合起来,给出了一种求解装配序列最优解的有效方法。首先通过转换算法将赋时Petri网转换为等价的普通Petri网,接下来给出普通Petri网可达状态及迁移引发函数的ZBDD表示方法,最后基于ZBDD给出最优装配序列求解算法。实例验证表明,该算法在求解过程中通过隐式符号操作实现了Petri网的可达状态搜索,有效缓解了计算过程中的组合复杂性。     

考虑作业空间约束的并行拆卸序列规划算法

为获取多人同时进行不同拆卸任务的并行拆卸序列,提出考虑拆卸作业空间约束的并行拆卸序列规划方法.首先从零件几何可行性、拆卸时间以及拆卸作业空间约束3个方面构建拆卸序列规划问题模型:为避免产生不可行序列,提出拆卸作业空间的快速提取和干涉检查方法;针对回收产品拆卸时间不确定的特点,引入区间数模型描述拆卸时间,从拆卸基本时间、拆卸工具准备时间和拆卸工位改变时间3个方面构建拆卸时间模型.然后基于协同工作原则设计蚁群搜索的等待机制,以求解并行的拆卸序列;为进一步提高算法求解复杂产品并行拆卸序列的质量和效率,采用具有自适应能力的信息素更新方式和蚂蚁选择策略对基本蚁群算法加以改进.通过一种锥齿轮减速器装配体实例对关键参数的取值进行讨论分析,并验证了该算法各项约束措施的有效性.     

改进蚁群算法在机器人路径规划中的应用

针对传统蚁群算法在移动机器人路径规划问题中存在的易陷入局部最优与收敛速度慢等问题,提出一种改进的蚁群算法。根据起点到终点距离和地图参数构建全局优选区域,提高该区域内初始信息素浓度,避免算法初期盲目搜素;利用局部分块优化策略分别对各个子区域进行寻优并更新区域内最优路径信息素,增强局部搜索能力,加快收敛速度;对全局路径进行寻优,更新全局最优路径信息素。在信息素更新公式中引入信息素增强因子,加强最优路径信息素含量,应用反向学习优化信息素,改进状态选择概率,提高算法寻优能力。实验结果表明,改进后的算法明显提高了收敛速度,同时寻优能力更强。     

自适应蚁群算法在求解TSP问题中的应用

围绕蚁群优化算法的理论及应用,针对蚁群算法在TSP规划中求解能力不足的难题,运用了一种基于自适应的蚂蚁算法,并对TSP规划进行了设计。为了提高路径规划的效率,将自适应与传统的蚂蚁算法相结合形成了自适应蚁群算法。仿真实验结果表明,改进后算法能够在较短时间内找到全局最优路径,相对于基本的蚁群算法在收敛速度、搜索质量和局部寻优方面都有了明显的提高。     

改进蚁群算法求解两地间时间最优路径

研究两地间时间最优路径的问题。针对基本蚁群算法搜索的盲目性,迭代时间长,易陷局部最优解的问题,造成寻找最优路径困难。为提高寻优效率,提出一种改进的蚁群算法来求解问题。在方案中引入阀值排序算法对搜索路径进行优化,解决了蚁群算法前期搜索路径的盲目性问题。改进的蚁群算法加快了收敛速度,并提高了稳定性。经仿真证明:改进蚁群算法性在减少算法的迭代次数和提高解的稳定性方面有了较大的提高,并且能很好的用于求解路径时间最优问题。     

一种模糊Petri网参数优化的有效方法

本文根据模糊Petri网运行时连续性的特点,以蚁群算法为基础,提出了一种带交叉、变异因子的模糊Petri网参数值寻优的有效方法。该方法先用分层思想建立无环路的FPN模型,然后把它转化为类前向神经网络以确定输入—输出层关系,并将网络中各参数的值域均分为10等份,在图形中用10个城市来表示,再用蚁群算法进行路径的寻优,寻优后,在蚁群选定的值域上产生具体的分量解,最后由误差函数确定是否需要重新寻优。仿真程序实例表明经蚁群优化算法训练出的参数正确率较高,且不依赖于经验输入数据。     

基于改进蚁群算法的机器人路径规划研究

在二维静态环境下的机器人路径规划中,采用基本蚁群算法寻优存在搜索时间较长、效率较低、容易陷入局部最优等问题。针对这些问题对基本蚁群算法进行改进,改进的蚁群算法使用不同的期望值机制,采用挥发系数自适应方式更新信息激素,并加入拐点参数作为路径的评价标准之一。对这两种算法进行仿真分析,可得改进后的蚁群算法比基本蚁群算法搜索能力更强,算法效率更高,所寻路径更短。结果表明,该改进算法提高了算法效率,抑制了算法陷入局部最优并实现了机器人最优路径搜索,使机器人可以快速地避开障碍物安全到达目标点。     

Disassembly sequence planning using component-joint graph and ant colony optimization

Disassembly sequence planning is an important step of mechanical maintenance.This article presents an integrated study about the generation and optimizing algorithm of the disassembly sequence.Mechanical products are divided into two categories of components and connectors.The article uses component-joint graph to represent assembly constraints,including the incidence constraints are represented by incidence matrix and the interference constraints are represented by interference constraints.The inspiring factor and pheromone matrix are calculated according to assembly constraints.Then the ant generates its own disassembly sequences one by one and updates the inspiring factor and pheromone matrix.After all iterations,the best disassembly sequence planning of components and connectors are given.Finally,an application instance of the disassembly sequence of the jack is presented to illustrate the validity of this method.     

基于几何推理的装配序列自动规划研究

以问题规约的求解策略和分解法规划产生的装配序列,提出与或图表达装配体拆卸序列解空间,通过求解拆卸序列与或图的解空间,得到装配体的拆卸序列;将拆卸序列反向得到装配序列,为降低装配体拓扑联接图的复杂度,以作业组件做出识别,文中提出判断零件可拆卸性的三个条件,使大部分零件无需进行干涉检验,而由逻辑推理即可判断是否满足拆卸条件,避免了多次试凑,有更高求解效率,可更广泛地用于装配序列求解上。     

An integrated approach to selective-disassembly sequence planning

De-manufacturing (DM) is defined as a process to disassemble certain parts or components from a product. The parts or components are selected for recycling, reuse, maintenance or disposal. Selective-disassembly as the disassembly of the selected parts is a key process in DM. Allowing a partial and non-procedural disassembly sequence in DM, selective-disassembly aims to minimize the number of removals regardless of assembly indenture levels. It is necessary for selective-disassembly to have an effective and optimal sequence planning in order to reduce tremendous time and cost involved in product DM. The Wave propagation (WP) method, a dominant approach to selective-disassembly sequence planning, focuses on topological disassemblability of parts. It is inefficient to achieve the aim because of two missed considerations: tool accessibility to a fastener in non-procedural and partial disassembly, and batch removability to directly access a part for separation or replacement.This paper presents an integrated approach to selective-disassembly sequence planning. The two examples presented here demonstrate that the approach is efficient and practical for DM. The implemented approach can efficiently generate a feasible and near-optimal sequence plan for selective-disassembly, with ensuring both batch disassembly of components and tool accessibility to fasteners.     

An New Approach to Represent Assembly Sequences

How to identify all feasible assembly sequences and compactly represent them is very important and necessary to computer-aided assembly sequence planning. An approach to get precedence relationships between components directly from assembly modeling is proposed in this paper. A representation method called disassembly sequence graph (DSG) is also presented in this paper. An example has been provided to illustrate the proposed approach.     

Interference probability matrix for disassembly sequence planning under uncertain interference

Disassembly of end-of-life products is a common step in remanufacturing and recycling. Disassembly sequence planning is the process that automatically finds the optimal sequence of components being removed. A key element of disassembly sequence planning is a suitable mathematical representation that describes the interference of any two components in a product. Previous studies on disassembly sequence planning have tended to focused on the interference that is fixed and known. However, the interference may be uncertain due to complex end-of-life conditions such as deformation, corrosion and rust. To deal with uncertain interference, this paper proposes an interference probability matrix as a new mathematical representation that uses probability to indicate uncertainty in the interference, and establishes a multi-threshold planning scheme to generate the optimal disassembly sequence plans. Three case studies are given to demonstrate the use of the proposed approach. It is also tested the performance of four multi-objective optimization algorithms that can be adopted in the proposed multi-threshold planning scheme.     

Disassembly information model incorporating dynamic capabilities for disassembly sequence generation

Industrial recycling and reusing is becoming more and more important due to the environmental and economic pressures. It involves disassembly activities to retrieve all the parts or selected parts. An information modeling for the disassembly and optimal disassembly sequence generation based on the information model becomes critical. Unlike the traditional graph based representation of product structure, this paper introduces an efficient and machine readable disassembly information model and then discusses a linear programming based optimization model for obtaining the optimal disassembly sequence from the proposed disassembly information model. A key feature of this approach is the incorporation and use of dynamic capabilities in its information model processing technique. Dynamic capabilities are added into the information model to handle state-dependent information such as parts' disassembly directions which may change after each disassembly operation. The overall information model is built in UML, and dynamic capabilities are represented as events in UML. The proposed method has been illustrated using an electrical–mechanical device.     

Human–robot collaborative partial destruction disassembly sequence planning method for end-of-life product driven by multi-failures

Partial destructive disassembly (PDD) of large complex products often requires human–robot collaborative disassembly (HRCD). Therefore, a human–robot collaboration partial destructive disassembly sequence planning (HRCPDDSP) method of end-of-life products driven by multiple failures is proposed to obtain the optimal disassembly sequence to improve disassembly efficiency and degree of automation. Based on the product disassembly priority and part failure characteristics, an information model of the HRCPDDSP method is constructed. Furthermore, the model is expressed as a constraint matrix and recycling decision matrix. A multi-layer chromosome coding method, including HRCD, destructive constraint, and node layers, is proposed of the characteristics of the HRCPDDSP method. The approximate optimal sequence of human–robot collaboration PDD is achieved by improving evolutionary mechanisms such as selection, crossing, and mutation. Finally, the model and algorithm are applied to solve a case of HRCPDDSP, and the feasibility and effectiveness of the proposed method are further verified by comparison with other disassembly modes.     

Collaborative optimization of robotic disassembly sequence planning and robotic disassembly line balancing problem using improved discrete Bees algorithm in remanufacturing✰

Remanufacturing helps to reduce manufacturing cost and environmental pollution by reusing end-of-life products. Disassembly is an inevitable process of remanufacturing and it is always finished by manual labor which is high cost and low efficiency while robotic disassembly helps to cover these shortages. Before the execution of disassembly, well-designed disassembly sequence and disassembly line balancing solution help to improve disassembly efficiency. However, most of the research used for disassembly sequence planning and disassembly line balancing problem is only applicable to manual disassembly. Also, disassembly sequence planning and disassembly line balancing problem are separately studied. In this paper, an improved discrete Bees algorithm is developed to solve the collaborative optimization of robotic disassembly sequence planning and robotic disassembly line balancing problem. Robotic workstation assignment method is used to generate robotic disassembly line solutions based on feasible disassembly solutions obtained by the space interference matrices. Optimization objectives of the collaborative optimization problem are described, and the analytic network process is used to assign suitable weights to different indicators. With the help of variable neighborhood search, an improved discrete Bees algorithm is developed to find the optimal solution. Finally, based on a gear pump and a camera, case studies are used to verify the effectiveness of the proposed method. The results under different cycle time of robotic disassembly line are analyzed. Under the best cycle time, the performance of the improved discrete Bees algorithm under different populations and iterations are analyzed and compared with the other three optimization algorithms. The results under different assessment methods and scenarios are also analyzed.