仿青蛙游动机器人机构设计

为研制仿青蛙游动机器人,设计了游动机器人机构.首先通过分析生物青蛙结构,设计仿青蛙机器人的原理样机.选择气动肌肉作为驱动器,分别驱动髋、膝、踝关节的转动,并采用钢丝传动结构,将膝关节气动肌肉安装在躯干上,从而有效减小了腿部的质量.建立了机器人系统的运动学模型并进行机器人运动学分析.分析了青蛙游动过程中的水下受力,并将水的作用力引入ADAMS仿真环境中,模拟了青蛙游动中的水环境,从而进行动力学仿真分析.最后对所研制出的仿青蛙游动机器人进行水下游动实验,其推进阶段平均速度达到339 mm/s.通过对比分析发现在动力学仿真和样机实验两种不同方法下机器人后肢运动形式基本一致,从而验证了仿青蛙游动机器人原理样机设计的可行性.     

仿生波动长鳍运动学建模及算法研究

长鳍波动推进鱼类在稳定性、机动性、低速下状态保持等方面较其它鱼类有着显著优势.本文将鱼类波动 长鳍抽象为零厚度理想波动而,引入直纹面建立曲线坐标意义下波动长鳍的运动学模型,描述了长鳍波动推进时的 非等幅波动、非对称波形等运动特征.面向理论分析和数值模拟,进一步扩充直纹面模型,使之满足弯曲基线、非零 厚度等长鳍形态及运动特征,进而建立筲卡尔坐标系下的长鳍波动描述方程,相应地,设计了鱼类长鳍波动推进的 运动描述算法.根据给定形体和运动参数,对零厚度理想波动板和弓鳍目"尼罗河魔鬼"鱼进行运动学仿真,验证 了运动学模型及运动描述算法的有效性.     

仿鱼柔性长鳍波动运动分析与建模

研究了弓鳍目鱼“尼罗河魔鬼”的柔性波动长背鳍.针对波动长鳍大的柔性变形特征,提出了由N根刚性鳍条依靠柔性薄膜连接组成的柔性波动长鳍简化模型;在分析长背鳍运动和流固耦合的基础上,建立了柔性波动长鳍的运动学模型;进而,从弹性薄壳理论出发,考虑柔性长鳍结构的几何非线性,并引入无矩薄壳理论的假定,建立了柔性长鳍波动的平衡方程.依据所建立的运动学模型和柔性长鳍波动的平衡方程,可以进一步解析柔性长鳍波动运动的动力学性能.     

基于CPG的仿生环形长鳍波动推进器运动控制

为了克服一般仿生水下机器人稳定性与机动性的不足,提出一种仿生环形长鳍波动推进器及其控制方法.根据环形长鳍波动推进器的结构特征和推进机理,提出了基于中枢模式发生器(CPG)的运动控制方法.该方法通过相邻耦合的方式,对波动推进器中20个频率和幅值可独立控制的神经元振荡器进行了建模,构建了一种用于该推进器的CPG网络模型.仿真分析了对称波形、非对称波形和环形波形推进控制方式下控制模型中的各振荡子输出信号,以及各参数对输出信号的影响,并试验研究了波形参数对样机游动速度和转弯速度的影响.试验结果显示样机具有一定的稳定性与机动性,直线游动速度和原地转弯速度随波动频率和波动幅值的增大而增大,最大直线游动速度可达109 mm/s,最大原地转弯速度可达93?/s.仿真及试验结果证明了此CPG控制模型的可行性和有效性.     

基于强化学习的波动鳍推进水下作业机器人悬停控制

本文针对波动鳍推进水下作业机器人的悬停控制问题开展研究. 首先, 给出了波动鳍推进水下作业机器人 的运动学模型、动力学模型和波动鳍的参数–力映射模型, 建立了基于马尔可夫决策过程的悬停控制训练框架. 其 次, 基于模型结构和训练策略, 使用强化学习的方法进行网络训练, 得到最佳的悬停控制器. 最终, 在室内水池中完 成了波动鳍推进水下作业机器人的悬停控制实验, 实验结果验证了所提方法的有效性.     

仿生魟鱼环形胸鳍波动推进的流场仿真

针对自主设计的仿生魟鱼水下机器人环形胸鳍波动推进过程进行了流场仿真研究。基于魟鱼前进运动时的胸鳍波动特征,建立了仿生环形胸鳍三维波动运动模型。利用CFD对胸鳍波动推进过程进行数值计算,分析了波动胸鳍产生的拉力以及前向运动的速度等推进性能。研究了周期波动过程中鳍面的周向压力分布,进行鳍面附近核心涡以及切面二维涡分量的计算,分析了涡的产生、发展以及尾迹涡的相关特性。结果表明,稳定后的拉力系数以近似正弦波形式进行波动,鳍面波动前后缘分布的高压和低压区域随波动沿周向从前往后传播,环形波动长鳍最终在尾迹处形成卡门涡,流场分析为仿生魟鱼水下机器人的运动控制及性能优化提供理论基础。     

蛇形机器人蜿蜒游动性能动力学仿真分析

模仿蛇在水中游动,设计了蛇形机器人仿真模型.通过蛇形曲线控制该机器人在动力学仿真水环境中实现蜿蜒游动.实验分析了蛇形曲线公式中起始弯角、S波个数、弧长变化率对蜿蜒游动性能的影响.实验结果表明:在一定范围内,增大蛇形曲线公式中起始弯角、S波个数、弧长变化率等参数的值,蛇形机器人的蜿蜒游动速率也随着增加.     

压电谐振驱动三足机器人的平面运动

设计并实现了一类利用压电陶瓷片作动,由三条曲梁足支撑的振动驱动机器人.建立了在一条足共振驱动下机器人水平运动的动力学方程,数值计算解释了摩擦作用下的运动机理,寻找到异性摩擦对运动方向、速度的影响和压电激励频率与运动速度间的关系.通过建立圆弧曲梁控制方程求解圆弧型足面内振动的固有频率及振型,设计了三组不同频率的圆弧曲梁足参数,实验制作了机器人模型,利用压电控制三足间振动的共振切换,实现了预想的三个方向的运动以达到平面运动的效果,实验测量了机器人的运动速度与理论计算吻合得较好.     

基于柔性长鳍波动推进的仿生水下机器人设计与实现

以基于柔性长鳍波动推进的仿生水下机器人试验模型为背景，主要研究其设计与实现问题．首先，介绍了仿生水下机器人试验模型的设计原则及其系统总体结构，然后重点研究了仿生柔性长鳍、主控模块与通讯系统、运动控制子系统的设计方法、系统构成和工作原理，最后介绍了试验模型的系统测试与航行试验结果及其结论，并指出了仿生水下机器人试验模型的改进重点和柔性长鳍波动推进技术今后的研究方向．基于柔性长鳍波动推进的仿生水下机器人试验模型的研制成功，初步验证了柔性长鳍波动推进方式应用于水下机器人推进控制系统在原理上和技术上是可行的．     

蛇形机器人侧向运动的研究

本文提出了一种新型蛇形机器人机构，建立了其空间运动学模型，实现了蛇形 机器人的两种侧向运动：侧向蜿蜒运动和侧向滚动，前者通过调节两个异相波的频率比，实 现了任意方向的侧向运动．后者通过控制运动波的幅值变化，实现了各种形式的纯侧向移动 ，当幅值足够大时，这种侧向滚动可以跨越障碍．     

A waypoint-tracking controller for a bionic autonomous underwater vehicle with two pectoral fins

This study aims to develop a waypoint-tracking control system for a biomimetic underwater vehicle (BUV). The BUV is propelled by wide paired pectoral foils, and each pectoral foil is driven by three independent fin rays. To simplify the control strategy, the maximum flapping amplitude of the pectoral fin is used to control the forward velocity, and a turning factor is defined for the manoeuvre control. Several swimming experiments are carried out to investigate the influence of the control parameters on the swimming performance of the prototype. Based on the results of the swimming experiments, a waypoint-tracking control system is proposed, which contains two layers: the velocity control layer and the heading angle control layer. A subdivision control method is adopted by the velocity control layer to get the maximum flapping amplitude. The fuzzy control method is employed by the heading angle control layer to obtain the turning factor for steering motion. Several waypoint-tracking experiments are carried out to verify effectiveness of the control system. The results show that the prototype can automatically reach the target area with the designed control system, even though the waypoints are arranged or randomly given.     

仿鲹科机器鱼的倒退游动控制

给出了一种新型的仿鲹科机器鱼倒退游动控制方法. 在已有多关节仿鲹科机器鱼的基础上, 仿照欧洲鳗鱼的倒退运动机理, 修正机器鱼尾部关节的摆动规律, 进而实现倒游运动. 给出鲹科机器鱼游动的定性分析, 用于分析仿鲹科机器鱼推进机理和倒退游动的方法. 组合其他运动, 实现倒退游动、倒游中转弯等运动. 通过实验, 给出了机器鱼摆动频率和倒退运动速度之间的关系, 验证了本文所提方法的有效性.     

Experimental study on the oscillating paddling gait of an ePaddle mechanism with flexible configuration

In this paper, a novel eccentric paddle locomotion mechanism (ePaddle) has been proposed to enhance the mobility of amphibious robots for multi-terrains tasks with diverse locomotion gaits. The oscillating paddling gait of the ePaddle mechanism enables the robot to perform stationary observation or attitude maneuvering operations in shallow water. To increase the thrust generated by this gait, the ePaddle mechanism has a flexible configuration, i.e. a flexible paddle and three rigid paddles. The effects of the oscillating amplitude and period of the gait to thrust are analyzed and compared with the thrusts measured with rigid configuration. Experimental results demonstrate that the flexible configuration is able to produce much more net thrust than the rigid configuration when the ePaddle is oscillating at large amplitude.     

胸鳍推进型机器鱼的CPG 控制及实现

结合仿生游动机理,针对胸鳍推进型机器鱼提出了一种基于中枢模式发生器（CPG）的运动控制方法． 该模型采用一类振荡频率和幅值可以独立控制的非线性微分方程作为其神经元振荡器模型,通过最近相邻耦合的方 式,对n 个这样的神经元振荡器进行耦合,构建了仿生机器鱼的CPG 网络模型．证明了此模型单个神经元振荡器的 极限环的存在性、唯一性及稳定性．在此基础上,通过对胸鳍推进的运动学分析,导出机器人直游、倒游、胸鳍—尾 鳍协调运动等多种模式的运动控制方法．仿真及实验结果验证了此中枢模式发生器模型的可行性与所提控制方法的 有效性．     

Design Optimization of a Bionic Fish with Multi-Joint Fin Rays

This paper aims to design a novel bionic fish propelled by oscillating paired pectoral fins. Flapping motion deformation of the nature sample, the cow-nosed ray, is realized with simple mechanical structure through optimization. Locomotion analysis of the nature sample under linear cruise swimming conditions is carried out. Simplified mathematical models of the pectoral fin are obtained to be the design foundation of the bionic fin rays and the bionic fish. The number of fin rays is decided according to the passing kinematic wave shape and number. Distance and structure parameters are optimized, and determined by the minimum area error method. A novel two-stage slide–rocker mechanism is designed to fulfill the driving requirements with only one servo motor. System design of a new bionic fish robot is presented, including the mechanical design and the control method. Main bionic characteristics extracted from the cow-nosed ray are fulfilled by the prototype and verified by experiments.     

形状记忆合金驱动仿生蝠鲼机器鱼的设计

研究了一种采用鳐科模式游动、柔性胸鳍摆动方式推进的形状记忆合金（SMA）丝驱动型仿生蝠鲼机 器鱼．首先,对双吻前口蝠鲼游动动作进行了分析,建立了蝠鲼胸鳍柔性摆动的简化运动模型．然后对能够模仿蝠 鲼肌肉动作的智能材料进行了分析．最后设计了SMA 丝驱动的柔性仿生胸鳍和仿生蝠鲼机器鱼,并分析了SMA 丝 的热力学特性,确定了控制规律．该机器鱼外形与双吻前口蝠鲼外形相似,身体呈现扁平形状,有一对三角形的柔 性仿生胸鳍,直线游动速度达到79 mm/s,最小转弯半径为118 mm．该机器鱼游动稳定性好,无噪声．     

Undulatory locomotion and effective propulsion for fish-inspired robot

Swimming, turning, and whip-sweeping propulsion for carangiform locomotion of a fish robot are investigated by means of a 4-link planar tail and an autonomous underwater vehicle (AUV)-like model. It is observed that excellent acceleration occurs when a whip sweeping behavior has been applied to the fish tail. The forward speed can even increases twice to the nominal swimming via the simulation study. The efficient movement is thus incorporated to the fish robot for agile movement. The robot's swimming patterns realize the effect in terms of the forward swimming, turning swimming, acceleration increasing, descended swimming, ascended swimming, depth regulating, and self-stabilization. Verification is accomplished by incorporating the 4-link planar tail, AUV-like model, and a two degree-of-freedom (DOF) barycenter mechanism. The four-link planar tail and 2-DOF barycenter mechanism act, respectively, as the thrust generator and stabilizing actuator for the fish robot. Sliding mode control (SMC) has been applied for three-dimensional (3D) trajectory tracking. Simulation results illustrate satisfactory performances of the fish robot in terms of the fish-like behaviors and maneuverability, which are due to the consequence of the mimicked predator-fish behaviors and performance robustness of the SMC for trajectory tracking under ocean current perturbations and modeling uncertainties.     

双鱼并排游动时水动力性能研究

随着水下仿生机器人的发展,人们开始关注鱼群个体之间的能量传输.鱼类在水中游动时,尾鳍摆动会与水相互作用,形成尾涡.鱼类会从附近尾涡中汲取能量,降低自身消耗.但是,有学者指出鱼群中不同摆动相位差个体之间存在相互干扰,阻碍鱼群前进,增加了自身能量消耗.使用一种在线实时功率检测系统,检测并排游动时两条机器鱼的纯功率、速度等鱼群水动力性能随着机器鱼摆动其相位差变化趋势.同时研究了双鱼之间横向距离对纯功率消耗影响,并结合纯功率和速度计算机器鱼推力.引入效率计算方法,并结合纯功率、速度和推力,计算和拟合效率分布趋势图.     

A Computational Fluid Dynamics （CFD） Analysis of an Undulatory Mechanical Fin Driven by Shape Memory Alloy

Many fishes use undulatory fin to propel themselves in the underwater environment. These locomotor mechanisms have a popular interest to many researchers. In the present study, we perform a three-dimensional unsteady computation of an undulatory mechanical fin that is driven by Shape Memory Alloy (SMA). The objective of the computation is to investigate the fluid dynamics of force production associated with the undulatory mechanical fin. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing is used to compute the unsteady flow around the fin through five complete cycles. The pressure distribution on fin surface is computed and integrated to provide fin forces which are decomposed into lift and thrust. The velocity field is also computed throughout the swimming cycle. Finally,a comparison is conducted to reveal the dynamics of force generation according to the kinematic parameters of the undulatory fin (amplitude, frequency and wavelength).