一种新型码垛机器人的机构设计及动态性能研究

发布时间：2019-04-11 18:33

【摘要】：现行码垛机器人以串联式为主,具有工作空间大的优点,但不足在于各关节处均装有驱动电机及减速器,使得机器人转动惯量大,导致动态性能不佳。本文提出一种新型的码垛机器人,利用多个平行可控四连杆机构,将主要的驱动电机、减速器等零组件置于机架或底座上,使原本被安装于串联式机器人关节处的电机及减速器位置高度得以大幅降低,减少了机械臂自身负载,以期改善关节铰接处出现的惯量大、整机刚度差等问题,为提升码垛机器人动态性能提供一种设计思路。本文对提出的码垛机器人展开了机构设计,运动学、动力学研究,包括考虑运动副间隙的机构运动特性以及机器人模态仿真分析等。运用D-H法、代数封闭解法对机器人的位置正、逆解问题进行了分析验算,通过微分运动法求解了机器人的速度问题,并对机器人的正、逆向运动学进行了数值仿真,同时,采用软件编程计算得到机器人的理论工作空间,验证机构设计的合理性;在进行机器人动力学研究时,考虑关节柔性带来的影响,对机器人进行刚柔耦合动力学建模并开展了仿真分析;此外,针对运动副的间隙问题,采用二状态间隙模型对简化后的码垛机器人机构展开了运动特性分析与仿真研究,通过对比分析有无运动副间隙时机构的运动仿真结果,发现运动副间隙的存在对机构运行的平稳度及精度有较大影响;最后,借助有限元软件经过模态仿真研究,得到了机器人三个典型位姿下的前六阶模态固有频率数值、最大变形量及振型图,根据各阶模态下机器人所表现出的振动形态特征,为避免机器人构件发生大变形、整机产生共振等振动故障提供预报和判断依据。
[Abstract]:The current palletizing robot is mainly series, which has the advantage of large workspace, but the deficiency lies in that each joint is equipped with drive motor and reducer, which makes the robot's moment of inertia large and leads to poor dynamic performance. In this paper, a new type of palletizing robot is presented, in which several parallel controllable four-bar mechanisms are used to place the main drive motor, reducer and other components on the frame or base. The position height of the motor and reducer installed at the joint of the series robot can be greatly reduced, and the load of the manipulator itself can be reduced, so as to improve the problems of large inertia and poor stiffness of the whole machine at the joint. It provides a design idea for improving the dynamic performance of palletizing robot. In this paper, the mechanism design, kinematics and dynamics of the proposed palletizing robot are studied, including the kinematic characteristics of the mechanism considering the clearance of the kinematic pair and the modal simulation analysis of the robot, etc. In this paper, the direct and inverse solutions of the robot are analyzed and checked by using the DH method and the algebraic closure method. The velocity problem of the robot is solved by the differential motion method, and the forward and inverse kinematics of the robot are simulated numerically, at the same time, the forward and inverse kinematics of the robot are simulated. The theoretical workspace of the robot is calculated by software programming, and the rationality of the mechanism design is verified. In the research of robot dynamics, considering the influence of joint flexibility, the rigid-flexible coupling dynamics modeling of robot is carried out and the simulation analysis is carried out. In addition, a two-state gap model is used to analyze and simulate the kinematic characteristics of the simplified palletizing robot mechanism, and the simulation results of the mechanism with or without the clearance of the palletizing robot are analyzed by comparing the two-state gap model with or without the clearance of the palletizing robot. It is found that the existence of the clearance has a great influence on the stability and accuracy of the mechanism. Finally, with the aid of finite element software and modal simulation, the first six modal natural frequency values, maximum deformation and mode shapes of the robot in three typical positions are obtained, and according to the vibration morphological characteristics of the robot under each modal, the first six modal natural frequencies, the maximum deformation and the mode shape diagram of the robot are obtained under the three typical positions of the robot. In order to avoid large deformation of robot components and vibration faults such as resonance of the whole machine, the prediction and judgment basis are provided.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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