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1.
以最小化生产周期、机床负载和机床与工人的费用为调度目标,基于受控Petri网和遗传算法提出了一种多目标作业车间调度方法,用于解决作业车间的加工受到机床、操作工人双资源制约条件下的动态优化调度.首先,给出了基于Parikh矢量的Petri网控制器简化设计方法,并应用该方法构建了基于紧急订单的受控Petri网模型;然后设计了基于Pareto的遗传算法,能够获得Pareto最优解集;尤其重要的是能够针对车间的动态扰动给出相应的调度方案.最后,通过实例验证了该方法的可行性和有效性.  相似文献   

2.
针对电器装配车间的特点,将装配线的作业调度分为车间管理决策层和车间装配单元执行层,建立了基于递阶优化理论的装配线作业调度模型.模型上层为车间管理层,以控制成本最低为决策目标;下层为N个平行的装配单元,以在满足车间层设备能力和资源配置约束的基础上,以完工时间最短为目标进行优化.并引入遗传算法对模型进行求解,通过实例验证了该模型的有效性和可行性,解决了车间管理层与车间层之间成本和能力利用平衡问题,实现了电器装配车间作业调度的自动化与优化.  相似文献   

3.
针对含有局部流水生产的柔性作业车间生产调度问题,首先在柔性作业车间调度问题的基础上建立调度模型,然后提出一种基于模拟退火法的调度算法,同时对加工路径和加工顺序进行优化,并实现最小化完工时间的调度目标。最后通过实例进行仿真,结果表明了算法的可行性和有效性。  相似文献   

4.
黄厦  李民 《机床与液压》2015,43(6):106-109
目前中国95%的制造业都为小批量多品种柔性作业企业,传统单目标车间调度模型已不能满足企业调度要求。同时实际企业生产多为"部分柔性"生产,但目前对于柔性车间调度问题的研究大都针对于"完全柔性"车间,对"部分柔性"车间涉及较少。首先分析了经典作业问题,然后结合实际"部分柔性"生产的资源约束以及顺序约束,并引入最小提前拖后惩罚目标,建立多目标部分柔性作业调度模型,同时构建了针对"部分柔性"的约束函数。  相似文献   

5.
针对柔性作业车间调度问题计算复杂度高,求解困难的难题,提出了一种离散多元宇宙优化算法。首先,建立起以最大完工时间为目标的柔性作业车间调度模型,使用两段式整数编码和贪婪插入解码建立算法与调度问题之间的联系;其次,设计宇宙种群初始化方法,以确保初始调度解的质量和多样性;然后,在基本多元宇宙算法的基础上,设计新的白洞选择,黑洞白洞传输和向最优宇宙移动机制,提高了算法求解柔性作业车间调度问题的性能。通过基准算例与其他智能算法比较,实验表明,所提算法可以有效的求解柔性作业车间调度问题。  相似文献   

6.
在分析车间作业计划的数学模型的基础上研究了在eM-Plant系统中建立车间作业调度仿真模型的关键技术,并且利用eM-Plant内置的遗传算法优化模块在现有仿真模型的基础上进行车间作业调度优化,最后以一个例子说明eM-Plant遗传算法模块的车间作业调度优化过程.  相似文献   

7.
用蜂群算法实现动态作业车间调度   总被引:3,自引:0,他引:3  
目前多数作业车间调度算法考虑的是静态调度,但在实际生产中车间总是处于动态变化中.文章研究利用蜂群与环境交互的模型来进行动态调度,提出了有关的算法,仿真实验结果表明这种方法适用于多批次以及各批次工件到达时间不定的情况下的作业车间调度.  相似文献   

8.
对柔性作业车间生产过程中预防性维护难以有效避免机器故障的发生,并且还存在各种无法预测的随机事件的问题进行了研究。为了有效应对这种情况,提出了多目标柔性作业车间鲁棒性调度与预防性维护的集成优化模型和在空闲时间进行预防性维护的策略,同时优化加工周期、机器可用性和调度方案的鲁棒性。应用多目标遗传算法NRGA对模型求解,并针对柔性作业车间调度问题的特点,采用三层编码方法。采用有效的交叉和变异操作避免产生非法解。最后通过模拟随机事件的发生进行仿真实验,结果表明提出的模型、维护策略和求解算法能够有效地提高生产效率、维护机器可用性、避免实际调度性能的恶化。  相似文献   

9.
最优生产技术在模具车间作业调度系统中的应用   总被引:1,自引:0,他引:1  
针对模具企业单件订货的特点,提出了在模具车间作业工中采用最优生产技术编排工序顺序,给出了模具车间作业调度系统的设计结构和建立在最优生产技术上的算法步骤。  相似文献   

10.
针对柔性作业车间绿色生产以及生产均衡性问题,提出一种面向柔性作业车间绿色生产的动态调整权重启发式算法。首先,根据柔性作业车间生产特点构建时间、能耗节能调度优化模型,基于调度模型提出综合优先规则,依据此规则对调度优先级进行干预,实现设备与工序的分层优化,获得高效、低耗的生产方案。在每一次迭代寻优过程中,通过缩短时间、能耗指标值与平均聚集距离的偏差率动态调整指标权重系数,保证时间、能耗选择的均衡性,避免优化过程陷入局部收敛,同时指导下一阶段的选择。最后,通过案例分析对比不同算法的优化结果,验证算法的有效性及准确性,为柔性作业车间生产提供指导。  相似文献   

11.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

12.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

13.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

14.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

15.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

16.
Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.  相似文献   

17.
正I take great pleasure in congratulating CHINA FOUNDRY journal on its 10th anniversary.The CHINA FOUNDRY journal started ten years ago.Since its inaugural,China has seen exceptional growth in the Castings Sector and rapid development in Machinery Industry.The journal is becoming an important communication platform for experts  相似文献   

18.
正Harbin General Hydraulic Machinery Works Co.,Ltd.of Yilin Hydraulic Group is the most professional production base of large-scale metallurgy oil cylinder and oil machinery cylinder in the Northeast of China.The main products include metallurgy cylinder,swell-shrink cylinder,rotating injection device,lifting cylinder,main lifting jack,front lifting jack,engineering oil cyl-  相似文献   

19.
正Weihai HHH Mach.Elec.Group is the most technical company focusing on Power transmission and Hydra-controlling.HHH has the ability of developing and testing of complete sets of transmission system with relevant technical training.HHH provide efficient,excellent cost-effective power transmission system and intelligent electric fluid transmission and control system to OEM customers,who are  相似文献   

20.
《中国铸造》2014,(5):460-463
The 9th China International Diecasting Congress and the 1st International Symposium on Nonferrous Alloys and Special Casting Technologies (ISNASCT) were successfully held in Shanghai on July 19-22, 2014. Both events were jointly sponsored by Chinese Mechanical Engineering Society, Die Casting Commission of World Foundry Organization and Non-Ferrous Materials Commission of World Foundry Organization, and organized by the Foundry Institution of Chinese Mechanical Engineering Society (FICMES) and China Productivity Promotion Center of Foundry Industry.  相似文献   

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