【作者】 高超；

【导师】 陶建国；

【作者基本信息】 哈尔滨工业大学 ， 航空宇航制造工程， 2015， 硕士

【摘要】 核救灾机器人中电子器件的辐射防护是需要解决的难点问题,而减少驱动的数量是目前有效的途径之一。欠驱动三指手,具有控制相对简单、可靠性高和形状自适应性好等优点。以欠驱动三指手作为核救灾机器人的末端执行机构,研究其抓取力学行为并进行分析意义重大。本文针对一种欠驱动三指手的抓持特性与开门抓持规划开展了深入研究。首先,对这种只有单一驱动的欠驱动三指手进行运动学分析,利用坐标变换矩阵,建立欠驱动三指手的整体坐标系。分析手指两个关节转角和三个手指间的运动关系。建立欠驱动三指手的静力学模型,得到传动箱驱动力矩与手指接触力之间的关系。建立闭门器的动力学模型,为含有闭门器的开门作业提供力学支持。利用接触力学中的赫兹接触理论,建立接触力和接触变形的关系,利用最小余能定理,把接触力分析问题转化为包含约束的非线性优化问题,利用增广型拉格朗日乘子法求解,解决了已知驱动力矩和物体所受的外力载荷,如何在静不定的情况下求解欠驱动三指手手指与物体真实接触力的问题。最后用手指包络抓取门把手得到的结果验证了模型的有效性。针对包络抓取和非包络抓取不同类型的门把手,欠驱动三指手与门把手距离以及中心线偏差作为变量,建立模型求解第一指节和第二指节的转角范围。比较包络抓取和非包络抓取门把手的优缺点。从接触力的角度出发,分析抓取稳定性问题,考虑了弹簧和摩擦的影响。比较分析两种典型的开门方式中,欠驱动三指手和门把手不同的位置关系对开门作业在接触力、开门可靠性和机械臂的影响。通过ADAMS Cable模块建立钢丝绳-滑轮系统,验证运动可行性。利用ADAMS和MATLAB/Simulink联合仿真,验证手指转角范围。利用ADAMS动力学分析,验证接触力模型的可行性。针对抓取过程中可能发生的弹射现象,提出相应的解决方案。更多还原

【Abstract】 As the executive mechanism of the nuclear disaster relief robot, conducting the research of the end-effector grasp is significant. Underactuated three-finger hand has the advantage of simple control, high reliability and shape adaptability. According to the end-effector grip planning and analysis, this paper has done the following work:Kinematics analysis was carried out on the underactuated three-finger hand, and using the coordinate transformation matrix, establish underactuated three-finger hand coordinate system, analysis the angle of two knuckles and three finger. The kinematics model of the three-finger hand is derived to get the relation of gearbox driving force and the contact force between the fingers and object. The dynamics model of the door closer is derived with the Lagrange approach which is benefit to open door.The relationship of contact deformation and the contact force is applied with the Hertz contact model. The contact forces analysis problem can be transformed into a nonlinear constraint optimization problem with the complementary energy minimal principle. Then the nonlinear constraint optimization problem can be solved efficiently with the optimized method of augmented Lagrange method. The question of how to solve the contact force has been resolved with the condition of actuator forces and external forces.The mathematical model has been made to solve the angle range of the first knuckle and the second knuckle with twisting the doorknob in different ways. To analysis the grab stability with the perspective of gripping force, spring and friction. Two different approaches to open the door are compared. Different ways to grasp the door knob are described under different angle of the plane between the three finger hand and door knob.To verify the feasibility of movement by establishing steel wire rope pulley system through ADAMS Cable module. It established the joint simulation platform for underactuated three-finger hand based on ADAMS and MATLAB/Simulink software to verify the feasibility of finger rotation. To verify gripping force model by dynamic analysis based on ADAMS software. For ejection phenomenon may occur during the grab, appropriate solutions has been proposed.更多还原