Electrostatically Actuated Robotic Fish: Design and Control for High-Mobility Open-Loop Swimming

This paper presents a project that aims at fabricating a biologically inspired robotic fish. The robotic fish is designed to be capable of propelling itself through oscillations of a flexible caudal fin, like a real underwater fish. In this paper, we describe the design features that underlie the operation of the robotic fish. These features include a unique actuator referred to as electrostatic film motor and a light and flexible power transmission system. The electrostatic film motor is made of two pieces of flexible printed circuit film and can be utilized as a new-type artificial muscle. The power transmission system permits reciprocating power to be converted to periodic oscillations and distributed to the caudal fin. Based on several design considerations inspired by biological concepts, we propose several open-loop swimming control strategies for the constructed robotic fish to accomplish fish-like motion (i.e., cruising, turning, and diving). Experiments of Seidengyo I, the first prototype of our electrostatic fish family, are carried out to confirm the validity of the original design and control. We further design Seidengyo II to improve on Seidengyo I and show the results of the experiments.     

Real-Time Models of Electrostatically Actuated Cantilever Probes With Integrated Thermal Sensor for Nanoscale Interrogation

Microcantilevers with integrated thermal sensor for topography measurement, which can be electrostatically actuated, are well suited for a highly parallel dynamic-mode operation where multiple cantilevers scan the media. Interpretation of data in dynamic-mode operation utilizing such cantilevers is complex because of diverse forces acting on the cantilever that include electrostatic, interatomic, structural, thermal, and, possibly, magnetic forces. In addition, the thermal sensor introduces new dynamics making interpretation of measured data challenging. In this paper, tractable models that are suited for real-time purposes, which can quantitatively predict the cantilever motion and the thermal-sensor measurement, are presented. Furthermore, it is demonstrated that all parameters of the model can be estimated solely from thermal-sensor data. This paper also provides a comprehensive understanding of the dynamics of the thermal sensor.$hfill$ [2009-0041]      

Robust Control of Spacecraft: Application to an Actuated Simulator

International Journal of Control, Automation and Systems - In this article, a hardware-in-the-loop implementation of two robust controllers based on high-order sliding mode and μ-synthesis...     

自适应光学仿真建模在SciSimu上的扩展

为了提高自主开发的组件建模与仿真平台SciSimu的自适应光学仿真和建模能力,将自适应光学系统码(CAOS)作为一个扩展添加到SciSimu。该文提出了一个使用接口库、自动管理和内置编译器实现扩展的设计原理。经过大量仿真项目的计算测试,证明该设计原理能让SciSimu具备自适应光学仿真能力,并且具有比CAOS更好的易用性和可扩展性。     

Adaptive Neural Region Tracking Control of Multi-fully Actuated Ocean Surface Vessels

In this paper, adaptive neural network region tracking control is designed to force a group of fully actuated ocean vessels with limited sensing range to track a common moving target region, in the presence of uncertainties and unknown disturbances. In this control concept, the desired objective is specified as a moving region instead of a stationary point, region or a path. The controllers guarantee the connectivity preservation of the dynamic interaction network, and no collisions happen between any ocean vessels in the group. The tracking control design is based on the artificial potential functions, approximation-based backstepping design technique, and Lyapunov's method. It is proved that under the adaptive neural network control law, the tracking error of each ocean vessel converges to an adjustable neighborhood of the origin, although some of them do not access the desired target region directly. Simulation results are presented to illustrate the performance of the proposed approach.      

冗余驱动并联机械手的混合位置/力自适应控制

针对冗余驱动并联机构研究一种自适应的混合位置/力控制算法.基于并联机构中约束子流形的几何性质,将冗余驱动并联机构的逆动力学自然投影到位形空间和约束力空间.基于投影方程,提出一种统一的具有渐进稳定性的自适应混合位置/力控制算法.采用最小二范数准则求解冗余解问题,实现了实际驱动关节力矩的优化.仿真结果验证了控制方法的有效性.     

状态反馈法改善MEMS静电驱动结构瞬时特性的研究

MEMS静电驱动结构的瞬时特性受其结构本身机械动态特性的影响,自然阻尼过高或者过低都可能会让系统发生操作偏差.利用状态空间分析法分析了MEMS静电驱动结构的工作机理.基于状态反馈原则设计了一种输入量控制方法,即根据系统要求指标来配置极点,实现最优控制.仿真实验结果证明,该方法能提高系统的瞬时特性.     

一种自适应混沌同步方法及其在信息传输中的应用

基于自适应误差反馈策略,利用同步误差对系统参数进行调整,并采取策略对信道噪声进行一定程度的补偿,实现了两个具有参数失配的混沌系统的同步。并在此基础上利用参数调制和参数估计策略,实现了信息传输。     

变论域自适应模糊PID控制系统仿真与应用

由于电液伺服系统具有非线性、时滞性等问题,自适应模糊PID控制方式仍难以精确控制马达转速,故设计了变论域自适应模糊PID控制算法。通过设计合适的伸缩因子,将变论域与自适应模糊PID控制相结合,该算法可以精确控制电磁比例阀的流量进而控制马达的转速。将PID控制、模糊控制、自适应模糊PID控制和变论域自适应模糊PID控制算法进行Matlab仿真,结果表明：变论域自适应模糊PID控制具有响应快、无超调、稳态误差基本为零的特点。通过可编程控制器实现了模糊PID控制与变论域自适应模糊PID控制算法在电液伺服系统中的应用,实验数据表明,变论域自适应模糊PID控制更加精确,符合工业控制要求。     

桁架自适应结构振动控制仿真实验研究

基于MATLAB／dSPACE综合仿真实验环境,在有限元结构分析的基础上,在MATLAB／Simulink中进行桁架自适应结构的数学模型搭建和控制方案设计仿真,由dSPACE软硬件系统实现自适应结构的主动元件驱动和传感器数据采集,从而实现半物理仿真。实验表明基于MATLAB／dSPACE综合实验环境桁架振动受到很好的抑制,证明MATLAB／dSPACE试验环境高效简洁,控制方法行之有效。     

Internal Preload Control of Redundantly Actuated Parallel Manipulators—Its Application to Backlash Avoiding Control

Redundant actuation of parallel manipulators can lead to internal forces without generating end-effector forces (preload). Preload can be controlled in order to prevent backlash during the manipulator motion. Such control is based on the inverse dynamics. The general solution of the inverse dynamics of redundantly actuated parallel manipulators is given. For the special case of simple overactuation an explicit solution is derived in terms of a single preload parameter. With this formulation a computational efficient open-loop preload control is developed and applied to the elimination of backlash. Its simplicity makes it applicable in real-time applications. Results are given for a planar 4RRR manipulator and a spatial heptapod.     

自适应模糊PID 控制在压射控制系统中的应用

压铸机工作环境恶劣,干扰较多,使参数发生较大变化,影响系统的稳定性,传统的PID线性控制在被控对象发生变化时,控制特性也随即发生变化。针对这个缺点,采用自适应模糊PID控制技术,并利用模糊控制的智能非线性特点来弥补PID控制器,从而对电液比例阀进行良好的控制,使系统达到一个最优的控制状态。通过实验仿真可知自适应模糊PID控制方法的可行性。     

A Phenomenological Discrete Brittle Damage-Mechanics Model for Fatigue of MEMS Devices With Application to LIGA Ni

Fatigue initiation and failure of various microelectromechanical systems (MEMS) is of significant importance as they gain widespread acceptance in sensors and electronics. This paper presents an approach for utilizing available experimental fatigue data to evaluate the fatigue lives of MEMS components. The approach is based on a phenomenological discrete material representation in which a domain is represented by a collection of rigid elements that interacts via springs along their boundaries. The principles of continuum damage mechanics are used to degrade the spring stiffnesses as brittle damage occurs when the domain is subjected to fatigue loading. The model utilizes experimental stress–life data for LIGA Ni to identify the material properties used in the model. The proposed model captures the statistical distribution of material properties and geometrical randomness of the microstructure commonly observed in a wide variety of MEMS. Consequently, simulations that account for the variability in fatigue life can be readily performed. The model is applied to a dog-bone-shaped specimen to evaluate the influence of material heterogeneity and material flaws on fatigue crack initiation life and scatter. The ability of the model to predict the fatigue life of different types of MEMS devices and loading conditions is also demonstrated by simulating the fatigue stress–life behavior of a MEMS resonator support beam. $hfill$[2008-0087]      

补偿模糊神经网络自适应逆控制的仿真研究

该文应用的补偿模糊神经网络（CFNN）是结合补偿模糊逻辑和神经网络的混合系统。由于引入补偿神经元使网络容错性更高,系统更稳定;同时模糊运算采用动态的、全局优化运算,并在神经网络学习算法中动态优化补偿模糊运算,使网络更适应,训练速度更快。将补偿模糊神经网络与白适应逆控制原理结合应用到某位置伺服系统噪声消除控制中,并同用BP网络,传统PID控制和常规模糊神经网络控制效果比较来证明此方法的优越性。仿真结果表明补偿模糊神经网络自适应逆控制在缩短训练时间,提高控制精度等方面都有显著改善。     

模糊控制在摆缸位置伺服系统中的应用

由于摆动气缸的摩擦转矩、空气可压缩性、比例阀的压力特性等非线性因素的存在,要得到摆缸伺服系统精确的数学模型十分困难,而且气动系统易受周围环境因素的影响,当采用传统PID控制时,很难使系统长时间保持良好的控制效果,尤其是当有一定的外界干扰之后会导致系统工作不稳定.利用Matlab实时仿真模块的功能,把模糊自适应整定PID的控制算法引入到伺服系统的控制器设计中,搭建的半实物仿真模型,对系统进行半实物仿真实验,并通过不断地在线修改控制规则,提高控制器的控制性能,实验结果表明,模糊PID控制效果良好.     

自适应光学波前控制算法的脉动阵列结构

提出了一种用于自适应光学波前控制算法的脉动阵列结构.该结构将波前控制算法分为递归运算和卷积运算两部分后,采用规范映射方法将其分别映射到脉动阵列,再将两个阵列链接以实现单路的波前控制运算.同时将处理单元共享引入阵列,并设计了以队列方式进行数据传递的脉动通信模式,将n路控制电压以分时复用的方式在一个阵列中串行计算以提高处理单元的利用率,减少硬件资源占用.实验表明,该结构具有控制流、数据流简单,硬件资源少等优点,且实时性强、模块化程度高.     

Speed-assigned Position Tracking Control of SRM With Adaptive Backstepping Control

A novel speed-assigned method is applied to the position tracking control of switched reluctance motor (SRM). A speed control freedom can be drawn into the position control through speed assignment. Adaptive backstepping control is used to design the position controller for the SRM. The accuracy of position tracking of the SRM can be enhanced with speed assignment. A disturbance observer is further designed to enhance the estimation accuracy of the unknown load torque. Simulation results certify that the design scheme is right and effective.      

无刷直流电机模糊自适应PID控制研究与仿真

针对传统的PID控制方式在对无刷直流电机系统控制时,存在精度低、抗干扰能力弱等不足,提出一种基于参数自适应模糊PID集成控制策略。首先,分析了无刷直流电机的数学模型,建立了基于双闭环调速系统的无刷直流电机控制系统模型,并对无刷直流电机双闭环系统转速进行模糊PID控制;然后,详细分析了建立该模糊自适应PID控制器的设计方法,提出一种优化模糊算子的优化方法,并运用仿真软件Matlab/Simulink实现了系统的设计和仿真;最后,在相同环境下,对比传统PID控制和模糊自适应PID集成控制两种控制策略的仿真结果。仿真结果表明,模糊自适应PID集成控制算法能使无刷直流电机双闭环控制系统具有更好的动、静态性能及较强的自适应能力。