Motor Driving Leg Design for Bionic Crab-like Robot

The paper presents the design of walking leg for bionics crab-like robot, which is driven with micro servo motor. The kinematic characteristics of the bionics machine are analysed for optimized structure parameters, which has been used in the robot design. A three closed loop motor control system structure for joint driver is also given, as well as the multi-joint driving system for walking robot leg.

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

Dynamic Bending of Bionic Flexible Body Driven by Pneumatic Artificial Muscles(PAMs) for Spinning Gait of Quadruped Robot

The body of quadruped robot is generally developed with the rigid structure. The mobility of quadruped robot depcnds on the mechanical properties of the body mechanism, It is difficult for quadruped robot with rigid structure to achieve better mobility walking or running in the unstructured environment. A kind of bionic flexible body mechanism for quadruped robot is proposed, which is composed of one bionic spine and four pneumatic artificial muscles（PAMs）. This kind of body imitates the four-legged creatures＇ kinematical structure and physical properties, which has the characteristic of changeable stiff＇hess, lightweight, flexible and better bionics. The kinematics of body bending is derived, and the coordinated movement between the flexible body and legs is analyzed. The relationship between the body bending angle and the PAM length is obtained. The dynamics of the body bending is derived by the floating coordinate method and Lagrangian method, and the driving tbrce of PAM is determined. The experiment of body bending is conductcd, and the dynamic bending characteristic of bionic flexible body is evaluated. Experimental results show that the bending angle of the bionic flexible body can reach 18. An innovation body mechanism for quadruped robot is proposed, which has the characteristic of flexibility and achieve bending by changing gas pressure of PAMs. The coordinated movement of the body and legs can achieve spinning gait in order to improve the mobility of quadruped robot.

Bionic Mechanism and Kinematics Analysis of Hopping Robot Inspired by Locust Jumping

A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.

Analysis on pivot turning of quadruped robot with bionic flexible body driven by the PAMs

The pivot turning function of quadruped bionic robots can improve their mobility in unstructured environment.A kind of bionic flexible body mechanism for quadruped robot was proposed in this paper,which is composed of one bionic spine and four pneumatic artificial muscles(PAMs).The coordinated movement of the bionic flexible body and the leg mechanism can achieve pivot turning gait.First,the pivot turning gait planning of quadruped robot was analyzed,and the coordinated movement sequence chart of pivot turning was presented.Then the kinematics modeling of leg side swing and body bending for pivot turning was derived,which should meet the condition of the coordinated movement between bionic flexible body and leg mechanism.The PAM experiment was conducted to analyze its contraction characteristic.The study on pivot turning of the quadruped robot will lay a theoretical foundation for the further research on dynamic walking stability of the quadruped robot in unstructured environment.

Stability margin of the quadruped bionic robot with spinning gait

Spinning gait is valuable for quadruped robot,which can be used to avoid obstacles quickly for robot walking in unstructured environment. A kind of bionic flexible body is presented for quadruped robot to perform the spinning gait. The spinning gait can be achieved by coordinated movement of body laterally bending and legs swing,which can improve the mobility of robot walking in the unstructured environments. The coordinated movement relationship between the body and the leg mechanism is presented. The stability of quadruped robot with spinning gait is analyzed based on the center of gravity( COG) projection method. The effect of different body bending angle on the stability of quadruped robot with spinning gait is mainly studied. For the quadruped robot walking with spinning gait,during one spinning gait cycle,the supporting polygon and the trajectory of COG projection point under different body bending angle are calculated. Finally,the stability margin of quadruped robot with spinning gait under different body bending angle is determined,which can be used to evaluate reasonableness of spinning gait parameters.

Modelling of thrust generated by oscillation caudal fin of underwater bionic robot

A simplified model of the thrust force is proposed based on a caudal fin oscillation of an underwater bionic robot. The caudal fin oscillation is generalized by cen- tral pattern generators （CPGs）. In this model, the drag coefficient and lift coefficient are the two critical parameters which are obtained by the digital particle image velocimetry （DPIV） and the force transducer experiment. Numerical simulation and physical experi- ments have been performed to verify this dynamic model.

Planning on Bionic Walking Gait of Quadruped Robot over Rough Terrain

A quadruped robot is more adjustable to a complex terrain than a wheeled or caterpillar robot to realize the continuous adjustable motions characterized by submissiveness and low energy consumption in basic control of the quadruped robot over rough terrain. This paper presents a static walking mode of ＂altitude hold＂, which means to keep absolute altitude by controlling limbs adjustably on the basis of which biokinetics studies have shown that quadrupeds can move with almost the same body altitude over rough terrains characterized by a nearly horizontal relief. The gait design specifies several characteristic states of stance phase and swing phase for a quadruped robot and controls the phase sequence and phase of four legs through change of characteristic states. Furthermore, we design a robot control system to generate adjustable gaits and control the coordinative movement of robot joints. This planning method is tested through ADAMS and MATLAB interactive co-simulation; the quadruped robot which has 8 degrees of freedom （8-DOF） is used to simulate the motion over a terrain character- ized by randomly arranged humps. The results show that this method can make the quadruped robot capable to walk over certain rough terrain.

基于MATLAB Robotics Toolbox的四足机器人轨迹仿真与优化

仿生四足机器人的足端轨迹对其运动状况具有重要作用。MATLAB Robotics Toolbox可用于机器人的建模、求正反解、末端轨迹规划等仿真与分析工作。四足机器人末端只有3个自由度的结构,通过MATLAB Robotics Toolbox来求解与仿真存在一定的缺陷。文中通过研究该工具箱的底层函数,发现出问题的原因是其中的"ikine"函数不适用。文中通过改用反解公式来代替"ikine"函数,对该工具箱进行有针对性的二次开发。同时,增加优化算法对逆向运动学的多解问题按照角度变化最小原则进行优选。对设定轨迹的实时动态仿真结果显示其行走的过程自然平缓,关节转动特性曲线在合理范围内,证明了该优化算法的有效性与合理性。

Design and Kinematic Analysis of a Novel Humanoid Robot Eye Using Pneumatic Artificial Muscles

This paper proposed a novel humanoid robot eye, which is driven by six Pneumatic Artificial Muscles （PAMs） and rotates with 3 Degree of Freedom （DOF）. The design of the mechanism and motion type of the robot eye are inspired by that of human eyes. The model of humanoid robot eye is established as a parallel mechanism, and the inverse-kinematic problem of this flexible tendons driving parallel system is solved by the analytical geometry method. As an extension, the simulation result for saccadic movement is presented under three conditions. The design and kinematic analysis of the prototype could be a sig- nificant step towards the goal of building an autonomous humanoid robot eye with the movement and especially the visual functions similar to that of human.

A Bio-Inspired Flapping-Wing Robot With Cambered Wings and Its Application in Autonomous Airdrop

Flapping-wing flight, as the distinctive flight method retained by natural flying creatures, contains profound aerodynamic principles and brings great inspirations and encouragements to drone developers. Though some ingenious flapping-wing robots have been designed during the past two decades, development and application of autonomous flapping-wing robots are less successful and still require further research. Here, we report the development of a servo-driven bird-like flapping-wing robot named USTBird-I and its application in autonomous airdrop.Inspired by birds, a camber structure and a dihedral angle adjustment mechanism are introduced into the airfoil design and motion control of the wings, respectively. Computational fluid dynamics simulations and actual flight tests show that this bionic design can significantly improve the gliding performance of the robot, which is beneficial to the execution of the airdrop mission.Finally, a vision-based airdrop experiment has been successfully implemented on USTBird-I, which is the first demonstration of a bird-like flapping-wing robot conducting an outdoor airdrop mission.

Research on Miniature Hexapod Bio-robot

This paper described the structure and control of a new kind of miniature hexap od bio-robot, analyzed the moving principle of the robot. The robot is based on the principle of bionics, its structure is simple, design novel, unique. It can mov e forwards and backwards. The external dimensions of bio-robot is: length 30 mm , width 40 mm, height 20 mm, weight 6.3 g. Some tests about the model robot were made. The experimental results show that the robot has good mobility.

Effects of reconfiguration on the performance of mobile navigation robot

An irmovative mobile robot that has reconfigurable loeomotion chassis and reconfigurable bionic wheels has been developed to meet the needs of different payload and different terrain. Several prototypes have been achieved by the recortfiguration. By modeling relative comparison coefficients, these prototypes are analyzed in terms of geometrical parameter of trafficability, static stability and maneuverability. The effects of reconfiguration on these indices of robot performance can be compared, i.e. the variable height of chassis h has the biggest effect, the variable length of chassis 1 is the second, then is the camber angle β and the caster angle α. Some principles for reconfiguration are proposed.

四足机器人腾空跳跃的轨迹优化与控制方法

针对四足机器人难以跨越大尺寸障碍物的问题,提出了一种仿生腾空跳跃的轨迹优化控制方法 .首先,对马里努阿犬的越障运动进行测试和仿生学分析,得到腾空跳跃的参考轨迹.其次,根据摩擦锥、轨迹平滑、运动学和动力学等约束条件,基于轨迹优化的方法对仿生参考轨迹进行离线优化,生成四足机器人的期望跳跃轨迹,得到跳跃所需的足端位置、关节力矩和关节角度序列.再次,设计分阶段的跳跃控制器,采用关节和质心PD(Proportional Derivative)的组合控制策略,实现对期望跳跃轨迹的跟踪,采用变刚度虚拟模型控制实现对落地姿态的调整和足底力的缓冲.最后,在Webots仿真环境中完成了1 m高度的自由落地和跳跃0.75 m高度桌子的仿真实验.研究结果表明:仿生轨迹优化与控制算法能够使四足机器人跳跃大尺寸障碍物并且具有平稳落地的效果,对于提高四足机器人的高性能运动能力以及拓展其应用环境具有参考价值.

仿生六足折纸机器人结构设计与运动分析

针对现有折纸机器人组成结构单一,运动不够灵活的问题,将折纸结构与多足机器人设计相结合,耦合三浦折纸和六折痕折纸,提出新型的仿螃蟹六足折纸机器人设计方案,扩展了折纸机器人的运动构型,提升了折纸机器人的运动灵活性.在面对称假设下,该机器人单足具有2个自由度,此时将机器人腿部顶点等效为关节,轴线折痕等效为连杆,建立机器人腿部的平面连杆等效模型,并以折面夹角为运动变量,通过仿真计算得出机器人足端的理论运动范围.利用楔形面板技术对折面增厚并避免相邻折面发生物理干涉,建模得到折纸仿螃蟹六足机器人的三维模型.基于平面连杆的等效模型,分析折面夹角与足端运动之间的联系,设计确定机器人的足端运动轨迹与运动步态.利用3D打印技术设计并制作折纸仿生六足机器人试验样机,基于STM32单片机控制实现了机器人三横向角步态运动.结果表明,该折纸仿生机器人可以实现平面构型到仿螃蟹构型的转换,在6条腿的协同运动下,机器人可以平稳地左右横向移动.

机器人灵巧手研究综述

机器人灵巧手可以模仿人类动作,完成复杂场景下的多种任务。机器人灵巧手的研究是开发智能人形机器人的关键技术之一。以机器人灵巧手的研究历程为核心,阐述了多指灵巧手的研究现状,分析了灵巧手的演化过程和研究进展。从自由度数目、驱动方式、机械传动方式和传感技术等方面探讨了灵巧手分类和特征,展望了灵巧手未来的发展趋势。

基于改进YOLOv5的仿生机器鱼目标检测算法研究

为满足仿生机器鱼目标检测的需要,在YOLOv5基础上提出了一种轻量级检测算法,降低算法复杂度并提高精度。首先对YOLOv5s模型进行改进,通过GhostConv和C3Ghost模块降低参数量和计算量。其次,引入CA和CoordConv模块增强特征提取和目标位置感知能力,采用soft NMS减少使用传统非极大抑制(Non maximum suppression,NMS)带来的漏检、误检,同时使用MPDIoU简化相似性比较,提升检测精度和召回率。最后,所提出方法在目标检测数据集上的试验结果表明,改进的YOLOv5网络体积更小、精度更高,证明了该算法的有效性和优越性。

受海龟爬行与山羊行走启发的四足仿生移动机器人多步态规划及动力学分析

为解决救援机器人运动速度慢、环境适应性差和步态单一等问题,参照海龟与山羊的生理结构,设计了一种四足仿生移动机器人。首先,根据海龟能在松软地面上爬行以及山羊运动能力强的特点,为机器人规划了仿海龟爬行和仿山羊行走两种步态以适应不同环境,提高了机器人的运动性能。然后,对机器人支腿进行了动力学分析,通过建立动力学模型来获取机器人关节扭矩与运动性能参数之间的定量关系。最后,通过仿真和样机实验来验证机器人步态的可行性以及机器人的环境适应能力。结果表明,所设计的机器人结构稳定,步态规划合理,可适应不同的复杂地形。研究结果可为仿生机器人的设计与开发提供重要参考。

仿生系统动力学与应用专刊序

围绕仿生系统动力学建模、设计理论与方法、非线性振动特征、控制方法等研究主题,本专刊介绍了仿生系统动力学与控制的一些创新性研究和工程应用成果.

仿生机器鱼步态控制及闭环运动控制方法综述

鱼类所具有的推进效率高、机动性强、环境扰动小等优点引发了国内外学者对仿生机器鱼的研究。底层步态控制方法和闭环运动控制方法是当前机器鱼控制研究的两大热点。按照推进模式的分类方法概述各类机器鱼的样机研制情况以及其性能优劣,介绍机器鱼的推进机理及其水动力学研究进展,进而重点探讨轨迹逼近方法和中枢模式发生器这2种底层步态控制思路,综述机器鱼的典型闭环运动控制方法。中枢模式发生器具有更强的灵活性、稳定性和可操作性,易于引入反馈项而实现闭环控制,在机器鱼底层步态控制中占主导地位。针对机器鱼的显著特点改进后的基于学习的控制方法与多种方法相结合后的混合控制方法具有更为广阔的发展前景,符合仿生机器鱼智能化的发展方向。根据工作条件和运动要求建立合理的步态控制系统以及准确高效的闭环运动控制系统可提高机器鱼的整体性能。