Untethered Micro/Nanorobots for Remote Sensing:Toward Intelligent Platform

Untethered micro/nanorobots that can wirelessly control their motion and deformation state have gained enormous interest in remote sensing applications due to their unique motion characteristics in various media and diverse functionalities.Researchers are developing micro/nanorobots as innovative tools to improve sensing performance and miniaturize sensing systems,enabling in situ detection of substances that traditional sensing methods struggle to achieve.Over the past decade of development,significant research progress has been made in designing sensing strategies based on micro/nanorobots,employing various coordinated control and sensing approaches.This review summarizes the latest developments on micro/nanorobots for remote sensing applications by utilizing the self-generated signals of the robots,robot behavior,microrobotic manipulation,and robot-environment interactions.Providing recent studies and relevant applications in remote sensing,we also discuss the challenges and future perspectives facing micro/nanorobots-based intelligent sensing platforms to achieve sensing in complex environments,translating lab research achievements into widespread real applications.

Explosive Electric Actuator and Control for Legged Robots

Unmanned systems such as legged robots require fast-motion responses for operation in complex envi-ronments.These systems therefore require explosive actuators that can provide high peak speed or high peak torque at specific moments during dynamic motion.Although hydraulic actuators can provide a large force,they are relatively inefficient,large,and heavy.Industrial electric actuators are incapable of providing instant high power.In addition,the constant reduction ratio of the reducer makes it difficult to eliminate the tradeoff between high speed and high torque in a given system.This study proposes an explosive electric actuator and an associated control method for legged robots.First,a high-power-density variable transmission is designed to enable continuous adjustment of the output speed to torque ratio.A heat-dissipating structure based on a composite phase-change material(PCM)is used.An integral torque control method is used to achieve periodic and controllable explosive power output.Jumping experiments are conducted with typical legged robots to verify the effectiveness of the proposed actuator and control method.Single-legged,quadruped,and humanoid robots jumped to heights of 1.5,0.8,and 0.5 m,respectively.These are the highest values reported to date for legged robots powered by electric actuators.

ACTIVE VIBRATION CONTROL AND SUPPRESSION FOR INTEGRATED STRUCTURES

The finite element dynamic model for integrated structures containing distributed piezoelectric sensors and actuators ( S/As ) is formulated with a new piezoelectric plate bending element in this paper. The problem of active vibration control and suppression of integrated structures is investigated under constant gain negative velocity feedback control law. A general method for active vibration control and suppression of integrated structures is presented. Finally, numerical example is given to illustrate the validity of the method proposed in this paper.

电动静液作动器的非线性变阻尼积分滑模控制

对于电动静液作动器(EHA),传统滑模控制器存在加速度信息难以获取,参数不易整定和控制信号抖振等问题,从而造成控制器很难应用于实际。针对以上问题,利用奇异摄动理论对EHA数学模型进行合理的降阶,从而使控制器设计避免了使用加速度信息。在此基础上,利用降阶模型设计了一种新型非线性变阻尼积分滑模控制器(NSMC),该控制器可根据位置控制误差实现系统阻尼比由欠阻尼到过阻尼的自适应调节,能有效提高位置阶跃调节性能。设计了一种基于滤波器的不确定项估计器对EHA中存在的参数不确定性和外部扰动进行实时估计并补偿。滑模面积分项的引入和不确定项估计器的使用,一方面使控制器中无需使用切换函数,实现了EHA的无抖振滑模控制,另一方面使系统整个动态过程完全表现为滑动模态,从而可根据EHA控制指标直接整定滑模面参数,大大简化了参数整定过程。同时利用Lyapunov稳定性理论对整个闭环系统和滑模面的稳定性进行了详细分析。分别与PI控制器、传统滑模控制器(SMC)和传统变阻尼滑模控制器(DVSMC)进行了详细的仿真分析比较,仿真结果表明NSMC能有效提高EHA位置跟踪性能和增强对参数不确定性和外部扰动的鲁棒性。

基于反步法的电磁气量调节执行机构自适应积分滑模控制

往复压缩机电磁气量调节执行机构是一种利用电磁驱动力控制进气阀启闭的装置。传统的脉冲电压控制方法存在高频快速响应与低落座速度的矛盾,以及抗扰动性能差等问题,为此,提出了一种基于反步法的自适应积分滑模控制。首先,针对电磁气量调节执行机构建立了考虑扰动的非线性模型;其次,利用反步法设计思想将高阶的电磁气量调节执行机构系统分解成了两个互相串联的低阶子系统,并在此基础上,结合滑模控制、自适应控制和积分控制的特点设计了一种复合型控制方法;最后,采用AMESim-Simulink联合仿真平台,对该控制方法与传统PID控制、滑模控制进行了不同角度的仿真分析对比。研究结果表明:在该控制方法下,电磁气量调节执行机构在的顶出和撤回过程中的最大跟踪误差平均值分别为9.6%和10.8%,平均落座速度分别为0.32 mm/s和0.98 mm/s,扰动造成的最大位移偏移量为1.3%。该控制方法能够保证跟踪误差快速收敛,提高位移跟踪精度,降低电磁气量调节执行机构的落座冲击,并对外部扰动具有强鲁棒性。

基于神经网络PI的电静液作动器温度补偿控制方法研究

电静液作动器(Electro-hydrostatic Actuator,EHA)作为一种高性能集成化的动力执行器,广泛应用于航天航空、工业生产和军事领域。在不同油液温度下,液压油的体积弹性模量、黏度等性质会发生变化,从而对EHA的控制精度产生影响。针对此问题,首先建立了EHA数学模型;其次,设计了反向传播(BP)神经网络对比例积分控制器(PI)控制参数进行在线调节,补偿温度变化对跟踪精度的影响;最后,通过实验验证了传统PI控制的EHA跟踪精度与温度变化有着密切关系,并将BPPI控制器与PI控制器进行实验对比。实验结果表明,所设计的BPPI控制器在不同油液温度下平均跟踪误差之间的差值较PI控制器降低80%以上;且在相同温度下,平均跟踪误差较PI控制器降低60%以上。

集成式电机主轴的力感知及微进给特性研究

为满足精密加工过程中对电机主轴的转速、进给距离和切削力精确控制的需求,将永磁同步电机和超磁致伸缩驱动器结合,提出一种具有转动、微进给及力感知功能的集成式电机主轴。为验证集成式电机主轴力感知部分的结构合理性,基于磁路法和有限元分析法,得出集成式电机主轴的微进给距离、外线圈感应电压与外部载荷的关系。最后,为验证仿真的准确性,搭建集成式电机主轴力感知及微进给试验平台。结果显示,在此磁路模型设计中,集成式电机主轴的磁通密度可达0.551 9 T,磁通密度均匀度大于77.85%,集成式电机主轴的微进给距离可达26.5μm,外线圈感应电压与外部载荷成反比且内线圈的最佳外加电流为5 A。研究结果表明,集成式电机主轴力感知及微进给功能的设计是合理可行的,为深入研究和精确控制集成式电机主轴奠定了基础。

MSMA自感知执行器的优化设计及试验验证

以磁控形状记忆合金为核心元件的自感知执行器是一种能够自我感知并自主响应的执行器,其具有很高的灵活性和智能性。针对现有自感知执行器的结构进行了优化设计。基于电磁理论分析和数学分析软件,以减小自感知执行器的磁路磁阻和励磁功率、增大气隙磁感应强度为优化目标,对自感知执行器的铁心和永磁体尺寸进行了优化设计;优化后的自感知执行器磁路磁阻减小,气隙磁感应强度增大,磁场分布均匀;通过搭建试验平台对自感知执行器的性能进行试验测试和分析,结果表明:在外加磁场大小相同和励磁线圈匝数相同时,优化后的自感知执行器与优化前的自感知执行器相比可显著提高感应电压峰-峰值并降低励磁功率,验证了自感知执行器结构优化设计的正确性与合理性。

融合光纤感知的气动执行器夹持力控制策略研究

为了降低气动执行器夹持力/气压迟滞的影响,提高夹持力跟踪控制精度,提出一种基于Prandtl-Ishlinskii(P-I)逆模型的前馈补偿结合模糊PID的控制策略。分析气动执行器的夹持力/气压迟滞特性,通过初载曲线法辨识迟滞模型参数,建立P-I逆模型;设计融合FBG力感知的模糊PID控制算法,基于自制的FBG传感器实现夹持力反馈,通过标定实验验证传感器的静态特性。在Simulink中构建前馈补偿和融合FBG力感知的模糊PID相结合的复合控制器,完成与传统PID以及模糊PID控制器的夹持力控制仿真对比。仿真结果显示:前馈补偿可以降低稳态误差,提高控制精度。最后,在气动执行器夹持力控实验平台上开展动态跟踪实验,验证了所设计复合控制器的有效性。

执行器攻击下神经网络事件触发滑模同步控制

针对多神经网络系统在执行器攻击和外部随机干扰下的同步控制问题,对事件触发滑模控制方法进行研究。首先,设计了2种新的积分滑模函数,保证多神经网络系统在整个同步过程中的全局鲁棒性;其次,在事件触发机制的基础上,针对系统存在有界扰动和执行器攻击的问题,设计了分布式事件触发积分滑模控制器,在抑制干扰和攻击的同时实现了多神经网络的同步控制,并且节约了通信资源;再次,基于李雅普诺夫稳定性理论,给出了多神经网络同步的充分条件,并通过推导得出最小触发时间间隔为大于0的正数,即保证系统不会存在奇诺(Zeno)行为;最后,仿真结果验证了所提控制方法的有效性。

光学遥感卫星精密敏捷成像控制技术综述

从控制的角度综述了多功能、高质量成像需求下,超稳定、超精确、超敏捷高分辨率光学遥感卫星精密敏捷控制的关键技术和研究进展。以卫星成像与姿态控制系统性能的关系为基础,从姿态机动能力与多功能成像、姿态确定精度与成像质量和姿态控制精度与成像质量三个方面论述了精密敏捷控制技术对光学遥感卫星成像的重要性。在此基础上,结合光学遥感卫星姿态控制系统的组成及原理,分析了影响姿态控制精度和姿态机动能力的主要因素,对高精度姿态确定、精密姿态控制和敏捷姿态控制三个关键技术方向进行了讨论和总结。最后,综合当前技术的发展趋势,围绕一体化成像控制的设计思想展望了精密敏捷控制技术未来的发展趋势,为实现高分辨率光学遥感卫星多功能、高质量成像控制提供了理论依据和工程参考。

面向交通工程钢筋笼焊接的机器人集成系统研究

随着钢筋笼结构在现代交通建设工程中的广泛应用,对于钢筋笼焊接的研究也在不断深入发展。针对交通建设领域因所用钢筋笼结构复杂而导致的焊接工艺繁琐等问题,本文以实现钢筋笼焊接高效化、智能化需求为目标,构建一种6自由度焊接机器人集成系统。本文提出一种运动自主规划与运动完全控制并行的控制方法,确保作业高效性与精确性。采用GJK算法和遗传算法构建防碰撞检测,实现安全作业。所构建焊接机器人集成系统和所提出控制方法,可为交通领域中钢筋笼焊接作业的智能化研究提供技术参考,可为钢筋笼焊接生产高效化、高品质化提供一种可行的方案。

电控气动离合器执行机构气路集成设计与研究

提出一种中央集成式嵌入型电控气动离合器执行机构,并从气路结构的集成设计、气路流体的仿真研究与气路响应性的试验研究3个方面与当前主流的半嵌入型电控气动离合器执行机构进行对比分析。结果表明,嵌入型电控气动离合器执行机构不但在零组件数量、接口数量、重量3方面具有优势,而且响应性更优。

Dynamics and Control of a Novel 3-DOF Parallel Manipulator with Actuation Redundancy

This paper deals with the dynamics and control of a novel 3-degrees-of-freedom （DOF） parallel manipulator with actuation redundancy. According to the kinematics of the redundant manipulator, the inverse dynamic equation is formulated in the task space by using the Lagrangian formalism, and the driving force is optimized by utilizing the minimal 2-norm method. Based on the dynamic model, a synchronized sliding mode control scheme based on contour error is proposed to implement accurate motion tracking control. Additionally, an adaptive method is introduced to approximate the lumped uncertainty of the system and provide a chattering-free control. The simulation results indicate the effectiveness of the proposed approaches and demonstrate the satisfactory tracking performance compared to the conventional controller in the presence of the parameter uncertainties and un-modelled dynamics for the motion control of manipulators.

Embedded integrated servo-controllers for intelligent modular actuators

This paper focuses on the development of an embedded integrated servo-controller （EISC） for servomotors. Comprising of mainly servo-controller and servo-amplifiers, this EISC is capable of controlling a wide range of servomotors to perform complieated tasks. Hence, integration of this EISC with a servomotor forms an intelligent modular actuator （IMA） that is essential to modern manufacturing industries. The development of such an EISC involves two major tasks： first, designing the hardware of a compact-sized and highly compatible EISC, and second, developing the software functions to facilitate its functionalities and capahilities. The developed EISC hence forms an integrated-servo-eontrol module, which determines the capability, functionality, flexibility and responsiveness of these IMAs.

Impact angle constrained fuzzy adaptive fault tolerant IGC method for Ski-to-Turn missiles with unsteady aerodynamics and multiple disturbances

An impact angle constrained fuzzy adaptive fault tolerant integrated guidance and control method for Ski-to-Turn(STT)missiles subject to unsteady aerodynamics and multiple disturbances is proposed.Unsteady aerodynamics appears when flight vehicles are in a transonic state or confronted with unstable airflow.Meanwhile,actuator failures and multisource model uncertainties are introduced.However,the boundaries of these multisource uncertainties are assumed unknown.The target is assumed to execute high maneuver movement which is unknown to the missile.Furthermore,impact angle constraint puts forward higher requirements for the interception accuracy of the integrated guidance and control(IGC)method.The impact angle constraint and the precise interception are established as the object of the IGC method.Then,the boundaries of the lumped disturbances are estimated,and several fuzzy logic systems are introduced to compensate the unknown nonlinearities and uncertainties.Next,a series of adaptive laws are developed so that the undesirable effects arising from unsteady aerodynamics,actuator failures and unknown uncertainties could be suppressed.Consequently,an impact angle constrained fuzzy adaptive fault tolerant IGC method with three loops is constructed and a perfect hit-to-kill interception with specified impact angle can be implemented.Eventually,the numerical simulations are conducted to verify the effectiveness and superiority of the proposed method.

饱和交通流状态下公共交通优先感应控制优化

文中以饱和交通流状态下公共交通优先作为研究对象,提出了一种以交叉口综合通行效益最大化为目标的感应控制方法,构建了以公共交通通行效率最大以及非优先相位排队时间最短为目标,以实时排队长度消散为约束的交叉口感应控制优化模型.并以实际交叉口为例进行仿真验证.结果表明:与现行的控制方案对比,优化方案既能够保障公共交通在交叉口优先通行,使交叉口人均延误减少15.64%,交叉口平均排队长度减少45.88%,又能够使非优先相位车辆的车均延误降低42.53%.

四旋翼无人机的高度和姿态容错控制研究

研究了四旋翼无人机执行器故障和外部干扰下的高度和姿态容错控制问题。首先,将执行器故障建模为螺旋桨推力定常效率损失(LoE),得到包含执行器故障的四旋翼无人机高度和姿态动力学模型;然后,基于积分终端滑模控制(ITSMC)设计了一种容错控制器,并结合自适应律对干扰进行估计和补偿,借助Lyapunov理论证明了闭环系统的稳定性;最后,数值仿真结果验证了所提出容错控制方案的有效性和鲁棒性。

基于滑模预测控制的水面无人船轨迹跟踪研究

针对全驱动无人船(USV)的轨迹跟踪问题,提出了一种模型预测控制和积分滑模控制相结合的双层控制方法。首先,针对无人船系统的运动学模型,设计模型预测控制器(MPC)根据期望轨迹得到满足约束条件的期望速度信号;针对动力学模型,设计积分滑模控制器(ISMC)使得系统在外界干扰存在的情况下,实现对期望信号的跟踪,提高了系统的鲁棒性;设计非线性干扰观测器对外界干扰进行估计,并在控制律的设计过程中进行补偿;最后,采用李雅普诺夫方法证明了系统的稳定性。数值仿真证明了两者的结合可以有效地实现全驱动无人船的轨迹跟踪。

压电执行器输出位移的精密自感知

为省掉外部精密位移传感器,进而减小微装配与微操作系统的体积,降低系统成本,采用自感知方法来获取压电执行器的输出位移。首先,基于压电执行器在电压作用下发生变形的同时,还会发生电极化而在其晶片表面产生电荷这一思想,提出了一种非平衡电流积分式压电执行器的位移自感知方法。其次,考虑到压电执行器的漏电流与介电吸收电流,以及运算放大器的偏置电流对自感知精度的影响,给出了能够精确反映压电执行器输出位移的自感知表达式及自感知参数辨识方法。最后,在辨识压电执行器自感知参数的基础上,实验验证了所提精密位移自感知方法的有效性,结果表明,自感知位移具有亚微米级分辨率,为0.24μm;在静态位移自感知方面,在0~118.9μm的位移范围内,自感知位移的最大相对误差为1.17%;在动态位移自感知方面,在0~100 Hz的频率范围内,自感知位移的最大相对误差为1.45%。可知所提出的精密位移自感知方法既能实现静态长时间又能实现动态快速的高精度、高分辨率的位移自感知。