刚柔耦合关节SCARA机器人的双柔性动力学模型

Dual-Flexibility Dynamic Model of SCARA Robot with Rigid-Flexible Joint

针对电子装配机器人高速高精要求,提出一种能够利用柔性铰链变形补偿轴承摩擦死区,实现高精度定位运动的刚柔耦合关节SCARA机器人的概念设计,并建立考虑柔性铰链变形与机械臂一阶弹性变形的双柔性动力学模型。首先,设计一种刚柔耦合轴承的结构,通过轴承中柔性铰链的变形量主动补偿摩擦死区引起的定位误差;在每个关节处引入两个扭转弹簧,分别模拟柔性铰链和机械臂的弹性变形;其次,建立关节的摩擦模型以模拟关节摩擦环境;然后,使用拉格朗日动力学方法建立包含摩擦信息与振动信息的动力学模型。设计开环和闭环的数值仿真进行验证,结果表明该模型理论分析的有效性。

For the high-speed and high-precision requirements of electronic assembly robots,the conceptual design of a rigid-flexible coupled joint SCARA robot which can realize the wide-range and high-precision positioning motion was presented.In addition,a dual-flexibility dynamic model is established,which considered the deformation of the flexure hinge and the first-order elastic deformation of the manipulator.Firstly,a rigid-flexible coupling bearing was designed,the positioning error caused by the friction dead zone can be compensated by the deformation of the flexure hinge.Two torsional springs were introduced at each joint to simulate the elastic deformation of the flexure hinge and the manipulator respectively.Secondly,in order to simulate the joint friction,a joint friction model was proposed.Then,the Lagrangian dynamics method was used to establish a dynamic model containing friction information and vibration information.Finally,the open-loop and closed-loop numerical simulations were designed for verification,the simulation results showed that the validity of the theoretical analysis of the model.