【作者】 王昊；

【导师】 梅杰；

【作者基本信息】 武汉理工大学 ， 机械工程， 2024， 硕士

【摘要】 轮腿式机器人兼具轮式机器人的高移动速度和腿式机器人的高越障能力,适用于灾后勘测等非结构化环境工况。为了增强轮腿式机器人的运动灵活性和移动稳定性,本文提出了一种基于并联脊柱的四足轮腿式机器人,并围绕该机器人展开了研究:(1)轮腿式机器人的机构设计。为了提高机器人的运动灵活性和工作空间,提出了一种具有轴向平移、水平扭转和垂直俯仰三个自由度的2UPS/1-UP并联脊柱机构。在此基础上对机器人的整体机构进行设计,机器人躯体采用矩形结构,分离两段式机身,四条轮腿均采用三关节串联结构,对称分布在躯体四周,机器人通过脊柱的运动获得更大的足端工作空间。(2)轮腿式机器人运动性能分析。采用改进D-H参数法分别建立轮腿、并联脊柱和整机的运动学模型,求解得到机构位姿与输入之间的关系。通过求解各机构的雅可比矩阵,进行速度传递性能的分析评估,提出了一种基于蒙特卡罗法的算法,求解出整机的工作空间。(3)轮腿式机器人步态规划。采用重心投影法作为稳定性判据,基于复合摆线法设计了足端的轨迹曲线。为机器人设计了轮式和足式两种移动构型,并对构型间的变换进行规划。为了增强机器人在足式构型下的灵活性和稳定性,提出了脊柱-轮腿协调运动的直行步态、转弯步态和越障步态,并对其动作序列进行了具体规划。(4)轮腿式机器人步态仿真与实验分析。在Adams中搭建仿真环境,对机器人的直行步态、转弯步态和越障步态进行仿真验证,考查分析了各步态的质心位移、足端轨迹和稳定裕度等运动性能。在仿真结果的基础上搭建样机进行实验,通过实验与仿真结果的对比分析,验证了各步态下的稳定裕度均大于零,机器人不存在倾覆风险,表明本文所提出的机器人结构和步态规划的正确性和可行性。更多还原

【Abstract】 Wheel-legged robots combine the high mobility of wheeled robots with the superior obstacle-climbing capabilities of legged robots,making them suitable for post-disaster reconnaissance and other unstructured environmental conditions.To enhance the mobility flexibility and stability of wheel-legged robots,this thesis proposes a quadruped wheel-legged robot based on a parallel spine mechanism and conducts research centered around this robot:(1)The mechanism design of wheel-legged robots.Based on the requirements for the robot’s mobility and operational performance in unstructured environments,the overall mechanism of the robot is designed,proposing a layout plan for the robot’s body,wheel-leg mechanism,and parallel spine mechanism.The robot’s body adopts a rectangular structure with a split two-part chassis,with limbs symmetrically distributed around the body.The wheel-legs use a three-joint series structure,and the spine employs a 2UPS/1-UP parallel structure.(2)Analysis of the wheel-legged robot’s motion performance.An improved Denavit-Hartenberg(D-H)parameter method is used to establish the kinematic models of the wheel-legs,parallel spine,and the entire robot,solving for the relationship between the mechanism’s pose and input.The velocity transmission performance is analyzed and evaluated by solving the Jacobian matrices of each mechanism.An algorithm based on the Monte Carlo method is proposed to calculate the workspace of the entire robot.(3)Gait planning for the wheel-legged robot.The center of gravity projection method is adopted as the stability criterion,and trajectory curves for the foot ends are designed based on the composite cycloidal method.Two types of mobility configurations,wheeled and legged,are designed for the robot,and the transitions between these configurations are planned.To enhance the flexibility and stability of the robot in its legged configuration,gait patterns such as straight-line walking,turning,and obstacle crossing,which involve the coordinated movement of the spine and wheels are proposed.Detailed planning is made for the sequence of these movements.(4)Gait simulation and experimental analysis of the wheel-legged robot.A simulation environment was constructed in Adams to validate the straight-line walking,turning,and obstacle-crossing gaits of the robot,examining and analyzing the motion performance such as the displacement of the center of mass,the trajectory of the feet,and the stability margin for each gait.Based on the simulation results,a prototype was constructed and tested.By comparing the experimental and simulation outcomes,it was verified that the stability margin for each gait was greater than zero,indicating no risk of robot overturning,which confirms the correctness and feasibility of the robot structure and gait planning proposed in this thesis.更多还原