基于变推进力的水下近端索驱动机器人结构设计及工作空间分析  

Structural design and workspace analysis of a winch-integrated underwater cable-driven robot based on variable thrust

作　　者：武昊 李国通 李东兴 唐晓强[1,2,3] WU Hao;LI Guotong;LI Dongxing;TANG Xiaoqiang(Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;State Key Laboratory of Tribology in Advanced Equipment,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipment and Control,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学机械工程系,北京100084 [2]清华大学机械工程系,高端装备界面科学与技术全国重点实验室,北京100084 [3]清华大学机械工程系,精密超精密制造装备及控制北京市重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2024年第10期1686-1695,共10页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金面上项目(51975307)。

摘　　要：面向水下各方向远距离、大空间作业任务,提出一种基于变推进力机构的水下近端索驱动机器人。该机器人采用六索及螺旋桨混合驱动形式,螺旋桨推进力大小和方向均可变,可等效为1根绳索。首先,对该机器人进行结构设计,提出采用近端驱动模式,并引入可改变推进力方向的A、B轴转角机构;其次,建立机器人的运动学与静力学模型,进一步针对推进力可变的特点提出一种基于二次规划的力可行工作空间计算方法;最后,对恒方向和变方向推进力下机器人的力可行工作空间进行分析。工作空间对比结果表明,推进力变向机构的引入使机器人的力可行工作空间显著增大,解决了已有水下多自由度机器人作业空间不足的问题。[Objective]Underwater multiple-degree-of-freedom robots possess a broad range of application potentials in diverse fields such as marine resource exploration,scientific investigation,and engineering construction and maintenance.However,during the execution of large-scale,long-distance underwater tasks,the conventional rigid serial and parallel manipulators frequently face the challenge of inadequate working range.Cable-driven parallel robots offer advantages such as large workspace,small inertia,and strong load capacity.However,prevalent cable-driven parallel robots for underwater applications are typically passively tensioned by gravity or buoyancy with their drive units(winches)mounted on a static platform,which constraints their motion ability and reconfigurability.Hence,a winch-integrated underwater cable-driven parallel robot based on a variable thrust mechanism is presented.The proposed robot adopts a hybrid drive form of six cables and a propeller.The thrust generated by the propeller,equivalent to cable tension,is adjustable in terms of magnitude and direction.[Methods]First,the overall mechanical structure of the robot is examined,and its kinematic and static models are established.On the basis of analyzing the judgment criterion of the wrench-feasible workspace(WFW),the wrench-feasibility testing problem under variable thrust is transformed into a constrained quadratic programming problem through the linear approximation method,and a new WFW calculation method is obtained.Then,a set of structural and force parameters of the robot are provided to evaluate and compare the WFWs of the robot with varied moving platform orientations and external forces under constant-and variable-direction thrusts.In addition,a large-span spiral trajectory is selected,a two-norm force index is implemented to optimize the thrust and cable tensions,and then the changes of all driving forces during the quasi-static motion of the robot on the trajectory are assessed under the two different thrust strategies.[Results]Calculation

关 键 词：水下装备 索并联机构 结构设计 工作空间 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]