基于CFD的仿鲹科机器鱼动力学建模与运动控制

仿生机器鱼的运动控制是仿生机器鱼推广应用的基础;然而,仿鲹科机器鱼的推进一般采用鱼体波数据,很少采用真实鱼类游动数据;为了深入探究仿鲹科机器鱼运动控制方法,采用了计算流体力学方法,通过标定流体介质、来流速度、鱼体几何形状等措施,利用Fluent软件进行了建模,然后针对鱼体波数据和真实金枪鱼游动采样数据两种不同推进数据对仿生机器鱼进行了仿真和实验;结果表明对于多关节仿生机器鱼推进方面,真实金枪鱼游动采样数据相较于常见的鱼体波产生的推进数据,在躯干进行大幅值摆动的情况下效果更好;这一仿真和实验对比为仿鲹科机器鱼的高效运动控制提供了一种新思路。     

基于舵机控制的仿生鱼设计

为实现仿生机器鱼的设计,分析鱼类游动的特点,基于舵机的工作原理,提出了自主避障的仿生鱼设计方案。根据鱼类推进理论,对仿生鱼进行了机械结构设计、软件设计。     

仿生机器鱼玩具的机构设计、仿真与实现

机器人技术的一个重要应用领域是在娱乐方面。在对鱼类游动方式深入研究的基础上，将仿鱼水下推进技术应用于玩具设计，给出了一种仿生机器鱼玩具的机构设计方案及系统的设计、仿真软件，并研制出可在水中运动的仿生机器鱼原型。     

水下仿生机器鱼的研究进展I——鱼类推进机理

仿生机器鱼技术是近年来水下机器人领域研究的热点之一 ,它为研制高效、高机动性和低噪声的水下运载器提供了新的思路 .本文以鱼的脊椎曲线为研究对象 ,提出了一种新的鱼类推进机理——波动推进 ,分析了波动推进过程中的运动阻力 .通过鱼类游动观测实验和仿生机器鳗鱼的研制 ,验证了该理论的有效性     

水下仿生机器鱼的研究进展I——鱼类推进机理

仿生机器鱼技术是近年来水下机器人领域研究的热点之一，它为研制高效、高机动性 和低噪声的水下运载器提供了新的思路．本文以鱼的脊椎曲线为研究对象，提出了一种新的 鱼类推进机理——波动推进，分析了波动推进过程中的运动阻力．通过鱼类游动观测实验和 仿生机器鳗鱼的研制，验证了该理论的有效性．     

用于避障研究的微型仿生机器鱼3维仿真系统

基于VC++6.0开发环境和OpenGL（open graphics library）国际图形标准,在Windows系统下开发了微型仿生机器鱼3维仿真系统。该系统可以降低用实体机器鱼进行机器鱼避障能力研究的成本和减少在研究过程中对实体机器鱼造成的损害。采用多边形建模的方法构建了虚拟微型仿生机器鱼模型,模拟了鱼类尾鳍的摆动。提出了一种模拟红外传感器探测障碍物的虚拟射线方法。并采用实时模糊决策算法设计了基于多传感器信息的复合模糊控制器,决策微型仿生机器鱼的避障行为。仿真实验表明,复合模糊控制器实时性好、效率高;无论是单个任意形状的障碍物还是多个连续障碍物,复合模糊控制器都能有效地引导仿生机器鱼避开障碍物,到达目标点。微型仿生机器鱼3维仿真系统为研究仿生机器鱼的自主避障能力提供了可靠、逼真、便利的平台。     

基于人工侧线的相邻仿生机器鱼感知研究

侧线系统是鱼类重要的感知器官,鱼类可以通过侧线器官实现对周围环境的感知,从而进行捕食、避敌以及一些群体行为.鱼类尾鳍摆动时会形成反卡门涡街,研究反卡门涡街对于仿生机器人的位姿和运动状态感知具有重要意义.以仿生机器鱼为平台、以侧线系统为依据,在机器鱼上实现人工侧线系统,当前方不同相对横向位置处机器鱼尾鳍摆动时,利用人工侧线实现对尾鳍摆动产生的反卡门涡街进行信息感知,从而间接识别机器鱼的相对横向位置,为群体机器鱼的相互感知提供了新思路.     

一种2自由度胸鳍推进机构设计与动力学分析

以箱鲀为仿生对象,设计了一种两侧胸鳍对称布置,单侧2自由度胸鳍能够实现摇翼运动、前后拍翼运动以及两者复合运动的仿生机器鱼,建立了其利用"划水模式"推进的水动力学模型,通过数值方法给出了胸鳍摆动周期、幅值以及初始角的变化与直线游动速度之间的关系,实验结果验证了其有效性.在此基础上,确定了所设计仿生机器鱼采用"划水模式"推进时的直线游动模态.研究结果表明,胸鳍"划水模式"推进的仿生机器鱼具有较高的效率和运动速度.     

基于微舵机控制的仿生鱼设计与实验分析

设计了微舵机控制的仿生鱼,结合鱼胸鳍和鱼尾鳍的配合动作,完成一系列的游弋动作。其中根据鱼类"波动推进理论"的游动机理,实现仿生鱼的前进、转弯运动;根据鱼类"胸鳍法理论"实现上浮、下潜运动;提出加减速游动方案,通过修改X值的方法,实现仿生鱼的加减速游。组装并进行水上模拟实验和水下实际实验,调试仿生鱼的各动作协调性,分析仿生鱼在水中的静态平衡和动态平衡问题。     

微小型仿生机器鱼设计与实时路径规划

提出一种结构紧凑, 运动灵活, 装配多传感器, 可自主游动的微小型仿生机器鱼系统设计方案. 在仿鲹科加月牙尾模式鱼类运动研究的基础上, 给出了微小型机器鱼推进、转弯等运动的控制方法. 结合运动控制和传感器信息处理, 给出了基于红外传感器的自主避障算法和基于光敏传感器的主动趋光算法, 进而提出了基于这两种传感器信息感知的动态光源跟踪方法. 通过实验, 给出了机器鱼尾部摆动频率、幅度和运动速度之间的关系, 验证了机器鱼追踪动态光源算法, 表明了本文所提系统设计方案和算法的有效性.     

A pectoral fin analysis for diving rajiform-type fish robots by fluid dynamics

In this paper, we analyze a propulsive force generated from pectoral fins for a rajiform-type fish robot from fluid dynamic aspects. A pectoral fin of the rajiform-type fish robot is constructed by multiple fin rays, which move independently, and a film of pushing water. Then, the propulsive force of the fish robot is analyzed from the momentum of the fluid surrounding for every fin between fin rays. The total propulsive force for one pectoral fin is the sum of these momenta. The propulsive speed of a fish robot is determined from the difference of the propulsive force generated from pectoral fins, and the resistance force that the fish robot receives from the water when moving forward. The effectiveness of the proposed method is examined through numerical simulation and actual experimental results.     

仿生机器鱼艏向摆动动力学仿真及分析

由尾鳍拍动产生侧向力导致的机器鱼的艏摇能够影响航行器的推进效率。该文首次运用Adamas软件埘北京航空航天大学机器人研究所“SPC—Ⅱ”仿生机器鱼进行了尾鳍受力分析和动力学仿真。从鱼体和尾鳍推进机构质阜比、拍动频率以及对尾鳍攻角的影响三个方面对仿真结果进行了分析，得出以下结论：随着鱼体和尾鳍推进机构质量比的增大以及频率的增大。艏摇不断减小；鱼体和尾鳍推进机构质量比小于78，没有出现共振现象；艏摇的存在会明显的衰减尾柄主臂和尾鳍攻角的角位移。     

仿生机器鱼俯仰与深度控制方法

提出一种基于重心改变法的仿生机器鱼俯仰姿态与深度控制方法, 用于实现机器鱼水中的浮潜运动. 该方法利用一种可调整位置的配重块结构, 改变机器鱼的重心位置, 进而实现机器鱼俯仰姿态的调节. 在对机器鱼内部配重块位置和机器鱼俯仰角的关系进行分析的基础上, 对一定速度下机器鱼的深度与俯仰角的关系进行建模, 提出由于尾部形变引起的俯仰姿态变化的补偿方法. 文中给出机器鱼原形样机的相关实验, 分析验证配重块位置变化和机器鱼重心及其姿态的调整, 深度控制等在多种情况下的结果.     

超磁致伸缩薄膜驱动仿生游动微型机器人

研制了以超磁致伸缩薄膜为驱动器的仿生游动微型机器人，其作业原理是以超磁致伸缩薄膜驱动器为尾鳍，通过改变时变振荡磁场的驱动频率，在超磁致伸缩薄膜的磁机耦合作用下,将时变振荡磁场能转换成驱动器的振动机械能，振动的超磁致伸缩薄膜驱动器再与液体耦合，便产生了机器人的推力．由于超磁致伸缩薄膜为非接触式驱动，因此机器人不需要电缆驱动．基于仿生游动原理，提出一种计算推力的数学模型，以建立的超磁致伸缩薄膜受迫振动模型的前三阶谐振频率模态为尾鳍的摆动，对振动薄膜产生的推力进行了计算．实验验证了理论分析的正确性，表明仿生游动微型机器人的方案切实可行．     

Design,modeling and experimental evaluation of a legged,multi-vectored water-jet composite driving mechanism for an amphibious spherical robot

This paper designs a novel legged, multi-vectored water-jet composite driving mechanism (LMWCDM) for the amphibious spherical robot (ASRobot) and presents modeling and experimental evaluation of this composite driving mechanism. In order to crawl on land flexibly, the robot was designed in SolidWorks and simulated in ADAMS environment with the sit to stand motion and a crawling gait. Then the simulation results, such as driving torques, guided the selection of servomotors in different joints. In aquatic environment, the dynamic modeling of ASRobot was analyzed by synthesizing the propulsive vectors of four propellers in each workspace of legs. Simplistically, multiple underwater locomotion, such as longitudinal and lateral motion, rotary motion, sinking and floating motion and cruising motion, were proposed. Thus, using a six-axis force/torque sensor at the equivalent mass center, a force and torque measuring mechanism was developed to obtain the direct propulsive effect and validate the modeling of the driving system. To evaluate the robot design and selection of servomotors, experiments of the sit to stand motion and crawling motion were conducted. Underwater testing experiments of LMWCDM were carried out to verify the modeling of rotary motion, sinking and floating motion. Besides, underwater test of the robot prototype also proved the highly flexible and swift motion.

     

Dynamic modeling of a CPG-governed multijoint robotic fish

This paper is devoted to the formulation of a dynamic model of a serially connected multijoint robotic fish with a pair of wing-like pectoral fins, in which the whole robot is treated as a moving multilink rigid body in fluids. Considering that the thrust of fish mainly results from the force of trailing vortex, added lateral pressure, and leading edge suction force, the dynamic equations of the swimming fish have been derived by summing up the longitudinal force, lateral force, and yaw moment on each propulsive component in the context of Lagrangian mechanics. Along with the bio-inspired central pattern generators (CPGs) as the locomotor controller, the overall dynamic propulsive characteristics of the swimming robot are then estimated in a mathematical environment (i.e. Mathematica). Finally, simulations and experiments are carried out to validate the effectiveness of the built dynamic model. Results demonstrate that the CPG-coupled dynamic model provides a fairly good guide to seeking pragmatic backward swimming patterns for a carangiform robotic fish.     

微创介入机器人系统设计与精度分析

针对微创介入手术对医生的身体危害性及难操作性等问题,设计了一种辅助医生手术操作的新型介入手术机器人系统,并详细阐述了模仿医生实际夹持与旋捻导管动作的仿生手指的设计理念以及基于神经网络的PID控制系统的设计过程。利用所研制出的血管介入机器人样机,开展了推进机构的精度实验,实验测试的各项精度结果证明所开发的推进机构满足精度的设计要求。通过对机构精度和误差来源的分析,给出提高精度的3条可行措施。本介入手术机器人满足设计要求,为同类产品的设计和改进提供了参考依据。     

Towards development of a slider-crank centered self-propelled dolphin robot

This paper is devoted to the mechatronic design and implementation of a dolphin-like robot capable of fast swimming. In the context of multiple coordinated control surfaces, a set of serially connected flapping modules is responsible for dorsoventral oscillations, an internal moving slider for pitch control and a yaw joint for lateral turns. To improve the swimming speed, an updated modular slider-crank-based flapping mechanism that fully capitalizes on the continuous high-speed rotation of the DC motor is proposed and constructed. With the proposed mechanisms, the resulting dolphin robot achieved a high level of propulsive speed, largely illustrating the validity of the present design scheme.     

A New Mechanism for Mesoscale Legged Locomotion in Compliant Tubular Environments

We present design and experimental performance results for a novel mechanism for robotic legged locomotion at the mesoscale (from hundreds of microns to tens of centimeters). The new mechanism is compact and strikes a balance between conflicting design objectives, exhibiting high foot forces and low power consumption. It enables a small robot to traverse a compliant, slippery, tubular environment, even while climbing against gravity. This mechanism is useful for many mesoscale locomotion tasks, including endoscopic capsule robot locomotion in the gastrointestinal tract. It has enabled fabrication of the first legged endoscopic capsule robot whose mechanical components match the dimensions of commercial pill cameras (11 mm diameter by 25 mm long). A novel slot-follower mechanism driven via lead screw enables the mechanical components of the capsule robot to be as small while simultaneously generating 0.63 N average propulsive force at each leg tip. In this paper, we describe kinematic and static analyses of the lead screw and slot-follower mechanisms, optimization of design parameters, and experimental design and tuning of a gait suitable for locomotion. A series of ex vivo experiments demonstrate capsule performance and ability to traverse the intestine in a manner suitable for inspection of the colon in a time period equivalent to standard colonoscopy.     

仿生机器鱼S形起动的控制与实现

给出一种仿生机器鱼S形起动的控制方法.结合北美狗鱼S形起动的形态特征及水动力学知识, 建立了多关节链式结构仿生机器鱼的S形起动模型.整个过程设计为两个阶段: 1)弯曲阶段:以转向速度最大化为目标.在鱼体S形变保证重心稳定平移的前提下, 增大较长转向力臂处的转向力矩,提高转向速度,使鱼体迅速转向目标方向. 2)伸展阶段:以增大前推力为目标.始终保持部分将要伸展的鱼体垂直前进方向,以L形滑动方式打开鱼体. 同时,为保证转向精度,采用模糊控制调节已展开鱼体关节的小角度转动,实时纠正鱼体展开所引起的游动方向偏离. 在S形起动末期,采用变幅值——频率的中枢模式发生器(Central pattern generator, CPG)实现向稳态游动方式的过渡:前期为保证游动方向及获取较大推进力,采用小幅值——高频率的CPG信号, 后期则进入大幅值——低频率的稳态游动.最终,采用四关节仿生机器鱼验证了该方法的有效性, 实现了峰值转速为318.08±9.20°/s、转向误差为1.03±0.48°的较好结果, 对提升水下游动机器人的机动性能具有指导意义.