仿壁虎机器人侧爬型地壁过渡步态Matlab仿真

通过观察自然界大壁虎的地壁过渡步态,结合已有仿壁虎机器人自身的结构特点,设计了一种仿壁虎机器人的侧爬型地壁过渡步态。利用Matlab软件求解了足端脚掌的运动空间以及落脚点的选择,对关键步态进行仿真,从而实现机器人的地壁过渡。对关键步态中间进行插值,以同样的方法求解即可得到整个过渡过程中的步态运动系列和电机旋转角度。研究表明,斜爬型过渡方式能够实现机器人互相垂直的地、壁面间的过渡运动。     

仿壁虎机器人的步态设计与路径规划

对仿壁虎机器人的步态规划问题进行探讨,在观察分析大壁虎爬行方式的基础上,总结出1324、伪1324以及对角线三种步态,并简要介绍不同步态规划之间的区别,最终选择对角线步态作为仿壁虎机器人的爬行步态。在此基础上设计仿壁虎机器人的直线位移步态规划和原地转弯步态规划。针对仿壁虎机器人的单足路径规划,根据步态规划结果将每一条步行足的运动过程分为支撑相和摆动相两种状态,通过对路径约束条件的分析,用多项式逼近的方法分别得出仿壁虎机器人单足路径支撑相和摆动相的一般性表达式,为计算关节控制量提供相应的依据。最后结合实际研制的仿壁虎机器人对步态路径规划进行实例仿真分析,得出支撑相和摆动相的位移时间关系,证明用多项式逼近的方法生成的路径曲线具有良好的起落特性,为仿壁虎机器人的稳定姿态爬行移动控制提供了理论依据。     

柔性杆连接的仿壁虎机器人结构设计

设计并研制具有柔性元件的可采用人造壁虎脚掌吸附材料的足式仿壁虎机器人结构。针对采用人造壁虎脚掌吸附的足式爬壁机器人,仿照生物壁虎设计基于连杆的仿壁虎机器人结构,进行运动原理分析,对机构进行简化,以及自由度计算。设计相应的运动步态,选用对角线步态实现机器人的直线行走以及转弯动作。为简化机构并使运动柔顺,采用柔性杆作为仿壁虎机器人的身体连接件,通过对机构自由度的计算,分析机构的可行性,并结合静力学分析对柔性杆的选择进行讨论。在Adams软件环境下建立虚拟样机进行仿真和测量,对各关节的受力情况进行分析。通过实物样机爬行试验,验证了设计的有效性和可行性。     

仿壁虎机器人地壁过渡步态规划与运动仿真

针对传统仿壁虎机器人空间运动能力不足、空间运动步态方法的可行性问题,基于仿生学原理,设计了一种具有腰关节的每条腿具有三个自由度的四足仿壁虎机器人,对仿壁虎机器人的结构进行了正运动学和逆运动学的分析,建立了各关节角度和机身空间坐标系下各参量之间的关系,在地面与墙壁交角为90°的工况下,根据其关于纵向平面对称的结构特点提出了一种对称式地壁过渡步态方法。在Matlab软件上对该步态方法的可控性进行了评价,利用各关节角度与各参量之间的函数关系编程得到了地壁过渡过程中各关节角度、角速度曲线,并在Inventor环境下进行了运动学仿真实验。研究结果表明,各关节角度、角速度均在允许范围内,且角度函数一次连续,验证了结构的合理性和步态的可行性。     

基于三维力反馈的仿壁虎机器人单腿运动控制

分析了仿壁虎机器人机构,建立机器人单腿的运动学模型,并通过代数法求逆解.静态标定三维力传感器并计算分析了传感器解耦矩阵,设计了力信号放大和滤波电路.建立足端黏附材料的弹簧模型,采用增量式关节运动方式,设计了足端三维力反馈控制算法.在Quanser的半实物仿真平台上验证了三维力反馈控制算法.实验表明仿壁虎机器人对足端三维力控制性能良好,三维力反馈控制算法可行,为具有力感知的仿壁虎机器人实现爬壁运动奠定了实验基础.     

六足仿蜘蛛机器人的结构设计与仿真分析

针对六足机器人运动规划问题,设计了一种六足仿蜘蛛机器人。首先,利用SolidWorks设计了六足仿蜘蛛机器人的机械结构;然后,通过建立六足仿蜘蛛机器人的D-H坐标系,构建了仿蜘蛛机器人行走机构的运动学模型,对机器人的单腿正、逆运动学进行了分析,推导了正逆运动学方程;最后,对几种典型步态进行了分析,运用多项式差值拟合的方法对仿蜘蛛机器人的摆动相及支撑相作了足端轨迹的规划;在此基础上,将SolidWorks模型导入到ADAMS/View中,利用ADAMS对几种典型步态进行了仿真,验证了对其步态规划的正确性。研究结果表明:该六足仿蜘蛛机器人的设计方案是有效的。     

四足机器人爬行凸起上坡的运动仿真研究

针对斜坡凸起环境下四足爬行机器人上坡时腿部受较大地面冲击的问题,设计了一种四足机器人的爬坡步态。首先,建立了三维柔性腿部结构模型;接着,针对斜坡凸起路面,对平坦路面下对角小跑步态的抗冲击性和稳定性进行了优化设计;然后,通过机器人单腿正、逆运动学分析,获得了斜坡对角小跑步态下四足机器人足端轨迹与关节角度的映射关系;最后,在斜坡凸起环境下对四足机器人进行了爬行运动仿真。研究结果表明:与平坦对角小跑步态相比,采用斜坡对角步态的四足爬行机器人质心位移更加平稳,其胫节足端接触力峰值较平坦对角小跑步态减小了8.05%,验证了所设计的爬坡步态的合理性。     

新型仿生六足机器人自由步态中足端轨迹规划

设计了一种具有变形关节和轮式足端的新型仿生六足机器人,该机器人具备轮式、爬行、步行等运动模式,有较好的灵活性及环境适应能力。运用矢量法构建了机器人运动学模型,并利用几何关系对模型进行求解。对机器人沿给定的路径执行自由步态时机器人所允许的最大步幅进行了分析。基于不同的地形条件,规划了抛物线和直线-抛物线两种足端轨迹。仿真结果表明,机器人在沿给定的路径执行自由步态时,抛物线和直线-抛物线两种足端轨迹规划方法合理、可行。     

两栖仿海龟机器人步态规划及分析

针对清淤机器人移动困难、稳定性差等问题,参考海龟的身体结构和爬行动作,设计出了一种两栖仿海龟机器人。在介绍机器人结构的基础上,利用D-H方法对机器人进行运动学分析,建立并求解了支腿的变换矩阵和运动学方程;规划了两种仿海龟爬行步态,根据机器人结构规划了电推缸的行程空间,并对足端轨迹和爬行步态做以优化;在ADAMS中进行运动仿真,分析了机体的位移和速度变化曲线。结果表明,优化后的步态可以大大提高机器人的爬行速度和稳定性。     

用于GIS设备内部爬行的仿壁虎机器人设计

根据气体绝缘金属封闭开关设备内部的作业需求,通过对壁虎的身体结构和运动规律的研究,设计了一种能在变电站气体绝缘金属封闭开关内部稳定爬行的基于真空吸附的仿壁虎机器人结构,并进行相应的控制系统硬件设计和控制系统软件架构设计。设计相应的运动步态,选用对角步态实现机器人的直线行走和横向行走。在理论设计的基础上,制造样机并在圆形管道内进行测试实验。实验结果表明,遥控器可以控制机器人端和真空吸附端,并且可以返回当前状态。在指令的控制下,机器人可以沿管壁进行前后和横移爬行。     

四足步行机器人关节位姿和稳定性研究

四足机器人爬行控制的关键是关节位姿的确定、机器人稳定性的判断和摆动腿顺序的选择.提出了一种求解关节位姿驱动变量的有效方法,此方法能获得满意的四足机器人步行步态.通过定义立足点的静态稳定区域提出了一种机器人稳定性分析的新方法,该方法不仅避免了复杂的机器人正动力学求解问题,同时还可给出机器人稳定性和立足点稳定范围的信息.实际爬行实验验证了所提方法的有效性.     

Planar jumping with stable landing through foot orientation design and ankle joint control

This paper introduces a method to generate the planar jumping motion for biped robot. In this work, through determining the upper body posture trajectory in the flight phase, the foot landing posture is made to be flat while landing. Together with properly designing the trajectory for local center of gravity and the foot landing velocity, the soft landing trajectory is generated. A controller on the ankle joint is added to avoid significant impact with the ground and stabilize the robot after landing. Jumping motion with stable landing is achieved in a dynamic simulation environment based on this method.     

新型轮腿机器人步态规划策略

设计了一种新型步态可切换轮腿机器人。该机器人步态切换机理易于实现且不存在冗余机构,驱动系统置于封闭空间内,可在两栖环境下应用。基于模型控制步态的策略,规划了轮腿机器人的足端轨迹;利用运动学模型分析求解出各关节变量,对步态控制策略进行研究,并利用实验样机验证了基于足端轨迹规划的机器人步态控制策略的可行性。     

基于GPL模型的仿生爬壁机器人路径规划

为了研究基于GPL模型的仿生爬壁机器人路径规划问题,提出了一种适合GPL模型的路径规划方法。首先对基于GPL模型的爬壁机器人进行了简单介绍,通过对GPL模型进行运动学、静力学分析,研究了该构型攀爬运动时机器人路径对攀爬能力的影响;其次,基于足端力最优得到了GPL模型腰关节的运动曲线,实现了路径规划;最后,采用ADAMS仿真验证了分析结果的正确性。结果表明,该方法可以解决基于GPL模型的爬壁机器人路径规划问题,同时研究结果也揭示了壁虎等生物原型采用摆动爬行而不是直线爬行的运动合理性。     

Energy efficiency analysis of quadruped robot with trot gait and combined cycloid foot trajectory

Quadruped robots consume a lot of energy, which is one of the factors restricting their application. Energy efficiency is one of the key evaluating indicators for walking robots. The relationship between energy and elastic elements of walking robots have been studied, but different walking gait patterns and contact status have important influences on locomotion energy efficiency, and the energy efficiency considering the foot-end trajectory has not been reported. Therefore, the energy consumption and energy efficiency of quadruped robot with trot gait and combined cycloid foot trajectory are studied. The forward and inverse kinematics of quadruped robot is derived. The combined cycloid function is proposed to generate horizontal and vertical foot trajectory respectively, which can ensure the acceleration curve of the foot-end smoother and more successive, and reduce the contact force between feet and environment. Because of the variable topology mechanism characteristic of quadruped robot, the leg state is divided into three different phases which are swing phase, transition phase and stance phase during one trot gait cycle. The non-continuous variable constraint between feet and environment of quadruped robot is studied. The dynamic model of quadruped robot is derived considering the variable topology mechanism characteristic, the periodic contact and elastic elements of the robot. The total energy consumption of walking robot during one gait cycle is analyzed based on the dynamic model. The specific resistance is used to evaluate energy efficiency of quadruped robot. The calculation results show the relationships between specific resistance and gait parameters, which can be used to determine the reasonable gait parameters.     

Method for six-legged robot stepping on obstacles by indirect force estimation

Adaptive gaits for legged robots often requires force sensors installed on foot-tips, however impact, temperature or humidity can affect or even damage those sensors. Efforts have been made to realize indirect force estimation on the legged robots using leg structures based on planar mechanisms. Robot Octopus III is a six-legged robot using spatial parallel mechanism(UP-2UPS) legs. This paper proposed a novel method to realize indirect force estimation on walking robot based on a spatial parallel mechanism. The direct kinematics model and the inverse kinematics model are established. The force Jacobian matrix is derived based on the kinematics model. Thus, the indirect force estimation model is established. Then, the relation between the output torques of the three motors installed on one leg to the external force exerted on the foot tip is described. Furthermore, an adaptive tripod static gait is designed. The robot alters its leg trajectory to step on obstacles by using the proposed adaptive gait. Both the indirect force estimation model and the adaptive gait are implemented and optimized in a real time control system. An experiment is carried out to validate the indirect force estimation model. The adaptive gait is tested in another experiment. Experiment results show that the robot can successfully step on a 0.2 m-high obstacle. This paper proposes a novel method to overcome obstacles for the six-legged robot using spatial parallel mechanism legs and to avoid installing the electric force sensors in harsh environment of the robot’s foot tips.     

四足轮腿式移动机器人的步态分析及轨迹规划

针对外星复杂的地表环境,基于2-UPS/(S+SPR)R闭环并联机构,设计了一种四足轮腿式移动机器人。通过对比机器人在运动过程中的稳定裕度与重心调整量得到最优步态,利用ZMP法衡量了机器人在静步态下的稳定性,并用改进的复合摆线法规划了足端的运动轨迹。在整个运动过程中,机械腿运动平稳,速度、加速度变化较为平滑,不会出现对机械腿造成损坏的较强冲击;且在抬腿和着地瞬间,速度、加速度均为0,不会对机身产生冲击。分析结果表明,该四足轮腿式移动机器人运动灵活且平稳,适用于外太空的探测。     

Energy dissipation rate control and parallel equations solving method for planar spined quadruped bouncing robot

This paper continues our investigation into Energy dissipation rate control (EDRC) and Parallel equations solving method (PESM). Our previous works showed how EDRC enables us to provide stable walking or running gaits for legged robots via controlling robot’s loss of energy rate during Impact phases (IP). This is while PESM facilitates the trajectory designing process of the robot’s active joints during each Single support phase (SSP) by solving the robot’s inverse kinematic and inverse dynamic equations in parallel. Even though PESM is very powerful and suitable for both quadruped robot, and despite the under actuation problem at the ankle joint, and biped robots, despite the presence of Zero momentum point criteria (ZMP) at the ankle joint, still, this method is limited to robots just with three and five DoFs. Therefore, the main purpose hereis to show how it is possible to extend the application of PESL to a spined quadruped robot with four DoFs by employment of the Central pattern generator (CPG) controller units and finding a connection among CPG’s output, PESM and the robot’s foot placement. Besides, as EDRC is employed to realize a stable bouncing gait for the robot, a whole numerical study is performed on the robot’s impact dynamic equations to evaluate the effect of spine joint on the robot’s impact dynamics.