Reactionless robust finite-time control for manipulation of passive objects by free-floating space robots

On-orbit servicing requires efficient techniques for manipulating passive objects. The paper aims at developing a reactionless control method that drives the manipulator to manipulate passive objects with high precision, while inducing no disturbances to its base attitude. To this end, decomposition of the target dynamics from the base dynamics is discussed, so that they can be considered as two independent subsystems. A reactionless nonlinear controller is presented, which ensures high-precision manipulation of the targets and that the base orientation is unchanged. This is achieved by combining the robust finite-time control with the reaction null space. Finally, the performance of the proposed method is examined by comparing it with that of a reactionless PD controller and a pure finite-time controller.

Conceptual exploration of a gravity-assisted electrorheological fluid-based gripping methodology for assistive technology

Gripping devices help patients carry out everyday tasks and increase their independence.However,there seems to be a lack of bionic gripping technologies that can fully adapt to any possible shape,as the use of artificial fingers and predetermined grip settings limits the operating space.The development of a more agile device,which is operated by a simple control paradigm,could greatly benefit users.An electrorheological(ER)fluid system should be able to adapt to the shape of an object and then hold that configuration.The aim of this study was to explore if a conceptual prototype of an ER system could hold a geometric shape when it is activated.A test rig was constructed with a moving part(set in different silicone oils)that could be displaced using a tensometer.Silica particles were dispersed in the silicone oils,and a field with a voltage of 4 kV mm?1 was generated to activate the fluid.The results show that the developed system can support an increased force when activated and hold a simple geometric position without any noticeable delay.This outcome provides an initial proof of concept for a possible new(gravity-assisted)gripping approach using smart fluids,which could be developed with materials that are biocompatible and widely available.

Overview of Key Technologies and On-orbit Verification of China Space Station

Tiangong space station is a space station independently designed and developed by China.In order to build and operate the space station,it was necessary to make breakthroughs in many fields and master several key technologies,which were characterized over a long technological span and underwent difficult verifications.Therefore,in addition to ground verification,on-orbit flight tests of key technologies for the assembly,construction and operation of the space station were planned to be conducted used by the core module,taking into account the differences in the gravity environment between space and the Earth,in order to lay a foundation for the subsequent comprehensive assembly,construction and long-term on-orbit operation of the space station.In this paper,the mission characteristics of the space station are briefly introduced,along with the key technologies for the assembly and construction of the space station,and then the on-orbit verification tests are comprehensively introduced.

An introductory review of swarm technology for spacecraft on-orbit servicing

This review paper presents a comprehensive evaluation and forward-looking perspective on the underexplored topic of servicing target objects using spacecraft swarms.Such targets can be known or unknown,cooperative or uncooperative,and pose significant challenges in modern space operations due to their inherent complexity and unpredictability.Successfully servicing space objects is vital for active debris removal and broader on-orbit servicing tasks such as satellite maintenance,repair,refueling,orbital assembly,and construction.Significant effort has been invested in the literature to explore the servicing of targets using a single spacecraft.Given its advantages and benefits,this paper expands the discussion to encompass a swarm approach to the problem.This review covers various single-spacecraft approaches and presents a critical examination of the existing,although limited,body of work dedicated to servicing orbital objects using multiple spacecraft.The focus is also broadened to include some influential studies concerning the characterization,capture,and manipulation of physical objects by general multiagent systems,a subject with significant parallels to the core interest of this manuscript.Furthermore,this article also delves into the realm of simultaneous localization and mapping,highlighting its application within close-proximity operations in space,especially when dealing with unknown uncooperative targets.Special attention is paid to the benefits that this field can receive from distributed multiagent architectures.Finally,an exploration of the promising field of swarm robotics is presented,with an emphasis on its potential to revolutionize the servicing of orbital target objects.Concurrently,a survey of general research directly engaging swarms in the orbital context is conducted.This review aims to bridge the knowledge gap and stimulate further research in the underexplored domain of servicing space targets with spacecraft swarms.

Active fault-tolerant control scheme of aerial manipulators with actuator faults

In this paper,an active fault-tolerant control(FTC)strategy of aerial manipulators based on non-singular terminal sliding mode(NTSM)and extended state observer(ESO)is proposed.Firstly,back-stepping technology is adopted as the control framework to ensure the global asymptotic stability of the closed-loop system.Next,the NTSM with estimated parameters of actuator faults is used as main robustness controller to deal with actuator faults.Then,the ESO is utilized to estimate and compensate the complex coupling effects and external disturbances.The Lyapunov stability theory can guarantee the asymptotic stability of aerial manipulators system with actuator faults and external disturbances.The proposed FTC scheme considers both actuator fault and modelling errors,combined with the adaptive law of actuator fault,which has better performance than traditional FTC scheme,such as NTSM.Finally,several comparative simulations are conducted to illustrate the effectiveness of the proposed FTC scheme.

Finite-time State Feedback Stabilization Method for a Class of Flexible Manipulators

Aimed at the finite-time stabilization problem of a class of flexible manipulators,a finite-time state feedback stabilization controller was proposed in this paper.Firstly,the nonlinear model of flexible manipulators was transformed into linear system through the exact state feedback linearization,and then using the finite time stabilization control method of the linear system,a finite-time state feedback stabilization controller was designed for the flexible manipulators.Furthermore,it was proved that all the states of flexible manipulators could be stabilized to equilibrium in finite-time under the proposed controller.The simulation results show that the performance of the flexible manipulators under the proposed finite-time state feedback controller is better than the traditional state-feedback controller.The proposed finite-time stabilization controller can improve the performance of the flexible manipulators.

89钻杆自动排放机械手设计与研究

为了解决目前人工辅助完成陆地钻台立柱存取存在排放工作劳动强度大、安全性低等问题,以KV3000钻井平台为大环境、89钻杆组成的立柱为研究对象,设计了钻杆自动排杆机械手。首先,对钻井过程中存取立柱的动作及时序过程进行分析;其次,采用动力学仿真分析方法对自动排放机械手进行干涉检查和行程检验,并针对核心零部件进行有限元分析。结果表明:研究装置可顺利完成钻杆存取工作,实现立柱在立柱盒与井口之间的位置转换,加速度均为线性,变化比较平稳,整体无较大波动;核心零部件最大变形为0.15167 mm,最大应力为59.875 MPa,均在允许范围。设备结构合理、运动轨迹规划合理、核心受力部件满足使用要求,提高了钻井作业过程中的自动化程度和安全性,为钻井作业钻杆自动排放提供了解决方案。

机械臂结构的发展与应用综述

机械臂以其独特的灵活性、强大的感知能力以及突出的适应能力被广泛应用于国防军事领域,如太空探索、工业装配、战场防爆等危险场景。通过仿生结构设计模仿生物体内微结构的排布方式与应急调控机理,可大幅度提升机械臂结构在复杂服役环境下的多功能适应性,提高生产效率、拓宽应用领域,推动科技进步。本文依据刚度特性将机械臂主要分为刚性机械臂、刚柔耦合机械臂和柔性机械臂三类,分别阐述了三类机械臂的优势、劣势、研究现状及应用情况,并从机械臂运动原理及结构设计方法、机械臂仿生设计的驱动方法及控制策略角度阐述了机械臂设计制造中的关键技术。最后介绍了仿生柔性机械臂在航空航天领域的应用现状及发展趋势。

空间站机械臂安全关键软件开发技术研究

空间站机械臂因其运动范围大、运动路径多变、控制精度要求高等复杂性,对软件的安全性和可靠性要求非常高。机械臂软件具有信息流处理多、控制功能复杂、实时性高的特点。文章根据我国空间站机械臂安全关键软件的开发设计工作,基于软件系统设计的概念,使用软件故障树分析(SFTA)和软件失效模式及影响分析(SFMEA)开展软件开发要点研究,分析了软件安全关键要素;对安全关键软件研制过程中的更改控制及应用环境控制进行总结,并介绍了地面验证与在轨应用情况。这些研究结果对提升航天器软件安全性和可靠性设计能力具有参考意义。

人形机器人的操纵性风险及规范进路

在人工智能大语言模型技术加持下,具有拟人化外观的人形机器人将具有操纵能力,可能引发限制人的自我成长、误导社会化进程以及扭曲家庭伦理观念等问题。风险管理进路是一种成本效益分析法,存在风险评估与分类困难,并非调整人形机器人活动的良方。人形机器人具有专精科技与赋能科技双重属性,前者意味着必须借助科技伦理规范研发活动,后者则要求充分关注不同应用场景的复杂治理需求。对人形机器人研发活动的规范,应适当将科技伦理法律化,预先控制人形机器人的情感计算能力,并避免外观设计产生过度操纵风险。对人形机器人应用活动的规范,一方面应充分借助法律系统抽象的权利义务工具,如知情权、人工沟通权以及人为监督、安全稳定义务等,回应海量应用场景引发的规范难题;另一方面应为法规、政策留出必要的空间,借助合规认证、监管沙箱等制度实现对人工智能赋能应用的协同治理。

基于数据驱动的冗余机器人末端执行器位姿控制方案

模型未知的冗余机器人执行任务的过程中会产生较大的控制误差,其末端执行器的位置与姿态也需要针对不同任务进行修正.为解决该问题,提出一种基于数据驱动的冗余机器人末端执行器位置与姿态控制方案.该方案使用在线学习技术,能够应用于模型未知的冗余机器人控制.同时引入四元数表示法将控制机器人末端执行器姿态问题转化为基于四元数表示的控制方法.随后,设计一种神经动力学求解器对所提方案进行求解.相关的理论分析、仿真及对比体现了所提方案的可行性、有效性与新颖性.

科技金融政策对战略性新兴产业上市公司研发绩效的影响——基于研发操纵视角

以促进科技和金融结合试点政策为准自然实验,利用2008—2019年战略性新兴产业企业数据构建多时点双重差分模型,基于研发操纵视角,实证分析科技金融政策对战略性新兴产业上市公司研发绩效的影响及内在机制。结果表明,科技金融政策能够显著抑制战略性新兴产业上市公司的研发操纵行为,从而显著提高研发绩效。平行趋势检验、安慰剂检验等一系列稳健性检验结果表明研究结果稳健。异质性分析结果表明,科技金融政策对研发操纵的抑制作用在非国有企业、东部地区企业以及上市年限较长的企业中更加显著。研究不仅能为科技金融政策的进一步推广提供理论依据,还可为促进战略性新兴产业上市公司研发创新提供政策启示。

中医推拿与康复技术相结合可行性分析

推拿与康复相结合在医疗保健领域极具优势,拥有广阔的发展前景。此文论述医学训练疗法(MTT)与传统功法训练相融合,康复评定贯穿治疗全过程,肌肉能量技术(MET)与扳法“、按拧法”与捏法的手法机制共通点,关节松动术和运动关节类手法的相似点,表明传统推拿与现代康复技术相结合具有可行性,以此可以拓宽推拿学科研究的发展道路,推动康复推拿学科的交叉发展,更好地服务于大众。

电磁超表面在隐身技术中的应用研究进展

电磁超表面能够利用散射调控和电磁波吸收2种主要机理进行隐身是隐身技术中一种极具潜力的新型技术途径。对电磁超表面在隐身技术中的应用与研究进展进行综述,首先介绍了超表面散射调控机理进行隐身设计的基本原理与实现方法,介绍了相位梯度超表面、编码超表面和超表面隐身套的发展历程和研究成果;其次介绍了基于吸波机理的超表面隐身技术研究进展,包括完美吸波结构、多频带吸波结构、宽频带吸波结构、宽角域吸波结构;再次介绍了超表面雷达隐身与其他功能的复合设计研究,包括超表面隐身强度复合设计、超表面吸波透波散射一体化、雷达红外兼容隐身等内容;最后总结了一些超表面在隐身技术应用中存在的问题和未来的研究方向。

基于PLC的采摘机械手的电气自动化技术研究

随着科学技术的不断发展,农业生产亦随之现代化、高效化,而在诸多信息化农业技术中,采摘机械手是较为突出的一种技术。如果能够在农业生产过程中用采摘机械手替代原本的人工采摘环节,不但可以提升采摘效率,同时也可以减轻人工压力和人工成本,从而使农业生产水平获得全方位的提升,进而提高种植户的经济效益。围绕可编程逻辑控制器(Programmable Logic Controller,PLC)的采摘机械手的电气自动化技术开展研究,分析该技术在我国的具体运用情况和基本原理,并根据现状提出若干建议,希望能够给予有关部门一定的参考与启示。

免举宫技术用于机器人辅助宫颈癌根治术的影响因素分析

目的:研究免举宫技术用于机器人辅助宫颈癌根治术的临床效果,并分析术后复发的相关因素。方法:收集2017年2月—2022年2月空军军医大学第二附属医院收治的248例行机器人辅助宫颈癌根治术的患者作为研究对象,根据手术方式的不同将患者分为两组。观察组行宫底悬吊免举宫机器人辅助宫颈癌根治术,对照组在宫腔内放置举宫器举宫后行机器人辅助宫颈癌根治术。回顾性分析两组手术治疗情况、手术后并发症发生率,对比其术后复发率,并采用多因素Logistic回归模型分析手术后复发相关因素。结果:两组患者术中出血量、引流量、手术时间及肿瘤病理分型比较,差异均无统计学意义(P>0.05)。观察组住院时间较对照组显著缩短,术后无复发生存率低于对照组,差异均有统计学意义(P<0.05)。两组术后首次排气时间和术后并发症发生率比较,差异无统计学意义(P>0.05)。多因素Logistic回归模型分析显示,宫颈深度浸润和盆腔淋巴结转移是术后复发的高危因素,采用免举宫技术是术后复发的保护因素。结论:免举宫技术用于机器人辅助宫颈癌根治术疗效显著,有助于降低术后复发率;宫颈深度浸润和盆腔淋巴结转移将显著增加复发风险。

同行管理层语调对企业绿色技术创新的溢出效应

技术创新是推动制造业绿色转型的重要途径。基于2009—2020年我国沪深A股制造业企业绿色发明专利数据和年报MD&A语调,探讨了同行管理层语调对企业绿色技术创新的影响效应。研究发现:同行管理层语调对企业绿色技术创新有显著正向影响,但该效应只发生在战略集团内部成员企业中,在跨战略集团企业间的影响作用不显著。两者之间的关系会受到企业盈利压力、市场竞争压力及媒体与分析师关注等因素的调节,并因管理者能力和企业产权性质存在异质性。而且,企业能够甄别同行管理层语调的操纵性行为。研究结论丰富了企业文本语言披露后果的相关研究,为洞悉企业绿色技术创新决策机制提供了新的经验证据。

3D视觉技术在铜冶炼质检系统中的应用

在铜冶炼过程中阳极板和阴极铜的外观质量会因工艺及其他原因发生波动,导致产品的物理外观影响生产和销售。在生产过程中,利用3D视觉技术对产品质量进行检测、统计和分析,为生产提供指导,可以减少因产品质量问题而引起的质量投诉。

困境与出路:操纵证券市场行为的治理对策分析

操纵证券市场行为通过虚构市场供求力量以扭曲股票交易价和交易量,并通过交易价差非法获利,破坏了公平有序的资本市场秩序。近年来,操纵证券市场行为出现复杂化、技术化、主体团伙化、跨市场、跨境化等特点,存在一定的治理困境,如犯罪手法不断演进凸显法律滞后;场外配资难以管理;操纵证券市场案件发现难、侦查认定难;跨市场、跨区域操纵交易致监管难度增大。为了防控操纵证券市场行为的发生,可以考虑采取科技赋能监管,加大监管力度;完善相关法律法规体系;减少犯罪黑数,提高违法犯罪成本;严格管理场外配资与出借证券账户行为;提高操纵证券市场行为的侦查能力等措施。

船舶综合导航系统发展现状及趋势展望

本文以船舶综合导航系统的介绍为切入点,阐述了船舶综合导航系统的定义及功能,由此对船舶综合导航系统的技术关键进行了研究。通过研究船舶综合导航系统的两大关键技术:导航传感器技术和导航控制技术,本文重点阐述了GPS技术、惯性导航系统(INS)、声学定位系统(SLS)和船舶自动操纵系统的技术情况,结合当前科技发展趋势,进行了展望与挑战分析,预测了船舶综合导航系统将向着智能化、自主化、可靠性等方向发展。