Motion planning for redundant prismatic-jointed manipulators in the free-floating mode

This paper investigates the motion planning of redundant free-floating manipulators with seven prismatic joints. On the earth, prismatic-jointed manipulators could only position their end-effectors in a desired way. However, in space, the end-effectors of free-floating manipulators can achieve both the desired orientation and desired position due to the dynamical coupling between manipulator and satellite movement, which is formally expressed by linear and angular momentum conservation laws. In this study, a tractable algorithm particle swarm optimization combined with differential evolution （PSODE） is provided to deal with the motion planning of redundant free-floating prismatic-jointed manipulators, which could avoid the pseudo inverse of the Jacobian matrix. The polynomial functions, as argument in sine functions are used to specify the joint paths. The co- efficients of the polynomials are optimized to achieve the desired end-effector orientation and position, and simulta- neously minimize the unit-mass-kinetic energy using the redundancy. Relevant simulations prove that this method pro- vides satisfactory smooth paths for redundant free-floating prismatic-jointed manipulators. This study could help to recognize the advantages of redundant prismatic-jointed space manipulators.

THE DEVELOPMENT PLANNING OF CHINA NATIONAL SERVICE STANDARD OF 2005-2008

According to the prime task of ''readjusting industrial structure,energetically developing service industry, completing service standards and promoting servicelevel'', which are raised in the 10th Five-Year Plan Outline of National Economy and SocialDevelopment, Standardization Administration of China (SAC), National Development and ReformCommission, Ministry of Civil Affairs of the People'' s Republic of China, Ministry of Constructionof P.R.C, Ministry of Commerce of the People''s Republic of China, Ministry of Culture of the People''s Republic of China, the People''s Bank of China, General Administration of Quality Supervision,Inspection and Quarantine of P.R.C (AQSIQ), the State Administration of Radio, Film and Television,State General Administration of Sport, National Tourism Administration, China Seismological Bureau,China Meteorological Administration, China Insurance Regulatory Commission, State Post Bureau, StateCultural Relics, State Administration of Traditional Chinese Medicine Bureau, China NationalTechnical Committee 264 on Service of Standardization Administration of China, China Consumers''Association and China National Institute of Standardization had compiled and officially ratified theDevelopment Planning of National Service Standard 2005-2008 by the end of 2005.

Challenges and Opportunities for China＇s Agricultural and Rural Development in the 12th Five-year Plan Period

Despite the great progress of rural socioeconomic development in the 11 th Five-year Plan period （2006-2010）, China＇s agriculture and countryside are still.lacing the challenges of a crude development pattern, backward rural development and cities＇ weak driving effect on the countryside. In the 12th Five-year Plan period （20I 1-2015）, China should transform the way agriculture grows and operates; promote rural socioeconomic development; improve urban planning and its functions, institutional innovation, and urban/rural integration to lay a solid foundation for building an all-round well- off society.

An Improved Binary Wolf Pack Algorithm Based on Adaptive Step Length and Improved Update Strategy for 0-1 Knapsack Problems

Binary wolf pack algorithm (BWPA) is a kind of intelligence algorithm which can solve combination optimization problems in discrete spaces.Based on BWPA, an improved binary wolf pack algorithm (AIBWPA) can be proposed by adopting adaptive step length and improved update strategy of wolf pack. AIBWPA is applied to 10 classic 0-1 knapsack problems and compared with BWPA, DPSO, which proves that AIBWPA has higher optimization accuracy and better computational robustness. AIBWPA makes the parameters simple, protects the population diversity and enhances the global convergence.

Plans for the Development and Revision of Industry Standards on Inspection and Quarantine from 2005-2007

The inspection and quarantine standard is one of important basics to executeinspection and quarantine by laws. In recent years, with the development of economy and trade inChina, standardization has played an important role in inspection and quarantine. During 2002-2004,department of Standards of Inspection and Quarantine, Certification and Accreditation Administrationof China has organized the research of the standards of inspection and quarantine, and has builtstandard sub- systems of nine fields in inspection and quarantine.

正规s^(n-p)部分因子设计最优区组和折叠反转方案

讨论了同时应用区组方案和折叠反转技巧时在sn-p正规部分因子设计中选择最优设计的问题,其中s是一个素数或素数幂.以分区组sn-p正规部分因子设计折叠反转的一般结构为基础,给出了组合区组设计的处理和区组裂区字长型的定义.该文证明了,对于已分区组的初始设计,它的组合区组设计的处理和区组裂区字长型与区组折叠反转方案无关.对于一个未分区组的初始设计,其组合区组设计定义的区组和折叠反转方案有最小混杂的充分必要条件是在不考虑区组方案时折叠反转方案有最小混杂,在不考虑折叠反转方案时区组方案有最小混杂.

基于改进RRT-Connect算法的移动机器人路径规划

针对双向快速扩展随机树算法RRT-Connect在移动机器人路径规划中生成路径绕远、转折多、收敛速度慢等问题,提出一种改进RRT-Connect算法。对新节点引入考虑祖代点的重选父节点环节,利用三角不等式原理优化部分路径长度,对每一个新节点的生成设置转角约束以减小路径转折,同时设计一种动态步长策略以加快算法的收敛速度。在两树连接阶段,为使拓展树之间能够平滑且快速连接,在连接处设置转角约束和距离约束,并使用同父节点重连的连接方法。实验结果表明,改进算法能够缩短规划路径长度和收敛时间,生成的路径质量较改进前更优。

Integrated use of GIS, remote sensing and multi-criteria decision analysis to assess ecological land suitability in multi-functional forestry

The Zagros forests are a treasure of valuable oak forests, but they have been severely degraded from long-term misuse. Geographic information systems （GIS） and multi-criteria decision analysis （MCDA） have been increasingly used to improve the management of vulnerable ecosystems to prevent further degradation and increase the sustainability of land use. This study presents a methodology to assess land suitability using remote sensing （RS） to obtain wall-to-wall data for the calculations, GIS to analyze the data, and MCDA to rank alternative land uses. The criteria and subcriteria affecting the suitability of land for different uses were identified and weighted using an analytic hierarchy process. Variables used as subcriteria were assessed using satellite data and other sources of information such as existing maps and field surveys. Numerical values for the subcriteria were classified, and each class was given a priority rating according to expert judgments. Based on the ratings and weights of the subcriteria, a priority map was created for each land use using the weighted linear combination method. The priority maps for different land uses were overlaid to obtain a preliminary land use map, which often indicated several simultaneous land uses for the same location. The preliminary map was further edited by removing unrealistic, mutually exclusive land-use combinations. The study tested and demonstrated the potential of integrating RS, G1S and MCDA techniques for solving complicated land allocation problems in forested regions using a scientifically sound and practical approach for efficient and sustainable allocation of forestland for different uses.

Association of TNF-α-238G/A and 308 G/A Gene Polymorphisms with Pulmonary Tuberculosis among Patients with Coal Worker’s Pneumoconiosis

Objectives Tumor necrosis factor-α （TNF-α） may play an important role in host＇s immune response to mycobacterium tuberculosis （M. tuberculosis） infection. This study was to investigate the association of TNF-α gene polymorphism with pulmonary tuberculosis （TB） among patients with coal worker＇s pneumoconiosis （CWP）. Methods A case-control study was conducted in 113 patients with confirmed CWP complicated with pulmonary TB and 113 non-TB controls with CWP. They were matched in gender, age, job, and stage of pneumoconiosis. All participants were interviewed with questionnaires and their blood specimens were collected for genetic determination with informed consent. The TNF-α gene polymorphism was determined with polymerase chain reaction of restriction fragment length polymorphism （PCR-RFLP）. Frequency of genotypes was assessed for Hardy-Weinberg equilibrium by chi-square test or Fisher＇s exact probability. Factors influencing the association of individual susceptibility with pulmonary TB were evaluated with logistic regression analysis. Gene-environment interaction was evaluated by a multiplieative model with combined OR. All data were analyzed using SAS version 8.2 software. Results No significant difference in frequency of the TNF-α-308 genotype was found between CWP complicated with pulmonary TB and non-TB controls （2,2=5.44, P=-0.07）. But difference in frequency of the TNF-α-308 A allele was identified between them （2,2-5.14, P=0.02）. No significant difference in frequencies of the TNF-α-238 genotype and allele （P=0.23 and P=0.09, respectively） was found between cases and controls either, with combined （GG and AA） OR of 3.96 （95% confidence interval of 1.30-12.09） at the -308 locus of the TNF-α gene, as compared to combination of the TNF-α-238 GG and TNF-α-308 GG genotypes. Multivariate-adjusted odds ratio of the TNF-α-238 GG and TNF-α-308 GA genotypes was 1.98 （95% CI of 1.06-3.71） for risk for pulmonary TB in patients with CWP. There was a synergic interaction between the TNF-a-308 GG genotype and body mass index （OR=4.92）, as well as an interaction between the TNF-α-308 GG genotype and history of BCG immunization or history of TB exposure. And, the interaction of the TNF-α-238 GG genotype and history of BCG immunization or TB exposure with risk for pulmonary TB in them was also indicated. Conclusions TNF-α-308 A allele is associated with an elevated risk for pulmonary TB, whereas TNF-α-238 A allele was otherwise.

基于空间句法的矿井应急疏散研究与应用

地下矿井作业危险,空间拓扑结构复杂,因而矿山安全事故时有发生,合理的应急疏散路线规划以及疏散指示布置,能够有效提高井下人员的逃生效率,降低人员伤亡与财产损失。结合某地下矿井实例,基于空间句法和GIS网络分析搭建地下矿井巷道网络模型,从逃生人员的空间认知角度出发,利用标准化角度选择度值选取巷道网络模型中的前景网络和背景网络作为主要避险通道,为应急疏散指示标志布置提供参考;考虑巷道宽度、巷道类型、巷道坡度等巷道基础属性信息,并结合空间句法指标——标准化角度整合度,构建巷道网络应急脆弱模型,顾及巷道空间单元的稳定性,规划井下人员的最优认知路径,进而实现了多目标的地下矿井紧急疏散路线规划。该研究不仅能够为地下矿井的巷道布局设计提供建议,还可为地下矿井的应急疏散路线规划辅助决策、应急预案制定提供理论依据,同时为紧急避险系统的建设与完善提供新的思路。

基于Pareto蚁群算法的双目标路径规划研究

针对复杂建筑环境人员应急疏散单一路径不能满足火灾环境变化需求的问题,基于改进蚁群算法,结合Pareto双目标解集思想,提出一种组合优化解集的双目标蚁群算法,通过排序优化的思想,实现人员多路径动态疏散规划。在构造Pareto解集的阶段协同考虑疏散路径长度以及火灾风险程度2个优化目标,计算各个解之间的支配关系。利用排序优化蚁群算法的正反馈机制将各组解的信息素按一定比例作为最优路径信息素的积累,加快解集的寻找。最后将其与传统双目标蚁群算法相比较,结果表明:优化后的双目标算法更加适合复杂建筑人员疏散路径规划问题,在寻找多组满足要求解的同时展示目标之间的利弊关系,供决策者选择合适的路径,提高疏散效率。

基于遗传算法改进的AGV路径规划研究

自动引导搬运车(AGV)节能路径规划可提高AGV使用过程的能效,是实现车间生产节能的一种可行方法。为解决AGV在栅格地图中规划路径时易出现的拐弯角度较多和穿墙等问题,并降低AGV在移动时的能耗,提出一种基于遗传算法改进的AGV路径规划方案。首先减少障碍物角点数,并将路径长度作为目标函数;然后对变异算子进行改进,减少拐弯次数,降低AGV在运动过程中的能耗,提高AGV运行的安全性。仿真结果表明,相比普通遗传算法,改进方法能够找到长度短、能耗更低且安全的路径。

An Intelligent Multi-robot Path Planning in a Dynamic Environment Using Improved Gravitational Search Algorithm

This paper proposes a new methodology to optimize trajectory of the path for multi-robots using improved gravitational search algorithm(IGSA) in clutter environment. Classical GSA has been improved in this paper based on the communication and memory characteristics of particle swarm optimization(PSO). IGSA technique is incorporated into the multi-robot system in a dynamic framework, which will provide robust performance, self-deterministic cooperation, and coping with an inhospitable environment. The robots in the team make independent decisions, coordinate, and cooperate with each other to accomplish a common goal using the developed IGSA. A path planning scheme has been developed using IGSA to optimally obtain the succeeding positions of the robots from the existing position in the proposed environment. Finally, the analytical and experimental results of the multi-robot path planning were compared with those obtained by IGSA, GSA and differential evolution(DE) in a similar environment. The simulation and the Khepera environment result show outperforms of IGSA as compared to GSA and DE with respect to the average total trajectory path deviation, average uncovered trajectory target distance and energy optimization in terms of rotation.

双层框架可视图下的双向跳点路径规划方法

针对移动机器人在复杂未知半未知环境下路径规划时间过长,难以找到全局最优路径的问题,该文提出了一种基于双层框架可视图的双向跳点搜索路径规划方法。首先,将可视图分为局部层和全局层,移动机器人通过传感器对环境信息进行采集与提取,生成局部可视图,接着采用基于障碍物轮廓边长的过滤方法将过滤后的图更新至全局可视图;其次,在跳点搜索算法的基础上新增一个从目标点开始搜索的路径,将跳点搜索算法优化为双向跳点搜索算法;最后,将优化后的算法结合可视图进行路径规划导航。将所提方法在多种复杂场景下进行验证,仿真实验表明:采用了双层框架可视图的双向跳点搜索算法的路径搜索时间和导航时间均有着不同程度的优化,可高效地在复杂未知环境下搜索全局路径。

机场航站楼出发层车道边前期规划设计研究

针对目前机场航站楼出发层车道边缺乏规范的设计流程和现有研究成果不能与工程实践有效结合等问题,对机场航站楼出发层车道边前期规划设计流程进行了系统研究。首先,构建了适用于前期规划设计阶段的机场航站楼出发层车道边设计流程,为工程设计提供了有效参考;其次,提出了车道边理论长度计算公式,结合国内主要机场的布局形式对新建项目的车道边横向布局提出了建议;再次,基于一定的假设,在2车道通行能力计算模型的基础上提出了3车道通行能力计算模型;最后,以济南遥墙国际机场T2航站楼出发层车道边为例,验证了上述设计流程和理论公式在前期规划设计阶段的适用性和可操作性。

机器人砂带磨削的曲面路径优化算法

机器人砂带磨削系统的两个显著优点是弹性接触和宽行加工,能够提高工件的表面质量和加工效率,主要用来完成复杂曲面特征工件的终加工。工件和接触轮之间存在曲面接触,机器人的磨削路径可由接触运动学理论和砂带磨削工艺相结合来生成,有关此方面的研究成果较少。在切削过程中,最重要的是要保证接触轮与工件曲面局部贴合,因此曲面曲率是磨削路径生成的主要因素之一。当曲面局部法曲率较小时,加工路径上的相邻刀位点之间弧长较长,保证加工效率;反之,加工路径上的刀位点致密,避免弓高误差超差。按照接触轮的宽度,生成一系列一定间隔的截面,提取截面与待加工曲面的割线。对于每一条割线,当曲率大于接触轮直径的四分之一时,增加一个中间刀位点,缩短了相邻刀位点之间的割线弧长。离线虚拟仿真验证了该方法的可行性。设计新算法与经典刀具路径规划方法的对比磨削试验,证明了该算法能够提高磨削质量。