基于力反馈的宏微机器人轴孔装配策略研究

发布时间：2019-05-24 00:54

【摘要】：伴随着机器人装配技术的不断改进提高,虽已实现了机器人的力伺服控制,但控制精度仍显不足使得装配效率不高,而实现智能装配、协作装配技术取得突破是“中国制造2025”提出的具体要求,因此如何实现快速、高效的智能装配迫在眉睫。本文主要围绕基于力反馈的宏微机器人轴孔装配策略展开研究,为最终实现宏微装配机器人的力伺服控制打下基础。1.并联微平台运动学正逆解分析。首先,确定了并联微平台的位置和姿态描述,依据动、静平台的矢量关系推出并联机器人运动学逆解方程,通过z-y-x欧拉角法则求解出微平台的逆解;然后,采用基于位置反解的杆长迭代法来求解并联机器人位置正解,并通过实例对其运动学正逆解进行了数值验证。结果表明,并联微平台的驱动杆可快速地逼近已知杆长,适用于实时控制和理论分析。2.轴孔装配的理论研究。首先,分析了轴孔装配过程,对轴孔接触状态进行了划分,重点对轴孔三点接触模型分别进行了力学分析和几何分析;然后,结合螺旋理论和虚功原理对轴孔装配过程中可能出现的各种接触状态进行了判别,并给出了力传感器坐标系与轴孔接触坐标系的变换矩阵关系;最后,给出了轴孔装配方案。3.基于改进人工势场法的末端执行器路径规划。为使装配机器人末端执行器具有良好的柔性,对传统人工势场法的斥力势函数进行了改进;然后,在Visual Studio 2010平台上建立了机器人末端执行器的路径规划仿真平台,并进行了机器人单一障碍物和多障碍物环境中的路径规划仿真实验,结果表明经典人工势场法存在的目标不可达问题得到了解决,验证了改进的人工势场法的有效性和实用性。4.微平台末端位姿调整策略规划与运动学仿真。首先,通过对六维力传感器反馈的力信息分析得到了装配力矢量在传感器中的6个分量,并推导出了其位姿求解公式;然后,基于解耦的六维力信息,提出了微平台末端位姿的调整策略;最后,通过对并联微平台结构的分析,运用参数化和模块化设计思想,基于Matlab/SimMechanics建立了微平台的物理仿真模型,结合Simulink给定微平台的运动轨迹实现并联微平台的运动学仿真实验,结果表明期望杆长与实际杆长之间偏差为0.04mm,误差为2.67%。5.微平台运动轨迹控制实验。首先,搭建了基于固高运动控制器的并联微平台运动控制实验平台;其次,通过对并联微平台控制系统进行点位控制模式和各轴状态设置,结合微平台的运动学分析,完成对微平台规划轨迹的运动控制实验;最后对实验结果进行分析表明,并联微平台的运动序列与规划轨迹基本吻合,验证了对并联微平台进行轨迹控制的有效性。
[Abstract]:With the continuous improvement of robot assembly technology, although the force servo control of robot has been realized, the control accuracy is still insufficient, so that the assembly efficiency is not high, and the intelligent assembly is realized. The breakthrough of cooperative assembly technology is the specific requirement of "made in China 2025", so how to realize fast and efficient intelligent assembly is urgent. In this paper, the axial hole assembly strategy of macro and micro robot based on force feedback is studied, which lays the foundation for the final realization of force servo control of macro and micro assembly robot. Analysis of forward and inverse kinematic solutions of parallel microplatforms. Firstly, the position and attitude description of the parallel microplatform are determined, and the inverse kinematic solution equation of the parallel robot is derived according to the vector relationship between the moving and the static platform, and the inverse solution of the microplatform is solved by z-y-x Euler angle rule. Then, the forward position solution of the parallel robot is solved by the rod length iteration method based on the inverse position solution, and the forward and inverse kinematic solution is verified by an example. The results show that the driving rod of the parallel microplatform can quickly approximate the known rod length and is suitable for real-time control and theoretical analysis. Theoretical study on shaft hole assembly. Firstly, the assembly process of the shaft hole is analyzed, and the contact state of the shaft hole is divided, with emphasis on the mechanical analysis and geometric analysis of the three-point contact model of the shaft hole. Then, combined with spiral theory and virtual work principle, all kinds of contact states that may appear in the process of shaft hole assembly are distinguished, and the transformation matrix relationship between force sensor coordinate system and shaft hole contact coordinate system is given. Finally, the assembly scheme of shaft hole is given. Path planning of end actuator based on improved artificial potential field method. In order to make the end actuator of assembly robot have good flexibility, the repulsive potential function of the traditional artificial potential field method is improved. Then, the path planning simulation platform of robot terminal actuator is established on Visual Studio 2010 platform, and the path planning simulation experiment in single obstacle and multi-obstacle environment of robot is carried out. The results show that the target unreachable problem existing in the classical artificial potential field method is solved, and the effectiveness and practicability of the improved artificial potential field method are verified. 4. Strategy planning and kinematic simulation of pose adjustment at the end of microplatform. Firstly, through the analysis of the force information fed back by the six-dimensional force sensor, six components of the assembly force vector in the sensor are obtained, and the formula for solving the position and pose of the assembly force vector is derived. Then, based on the decoupling six-dimensional force information, the adjustment strategy of the position and pose at the end of the microplatform is proposed. Finally, through the analysis of the structure of parallel microplatform, the physical simulation model of microplatform is established based on Matlab/SimMechanics by using the idea of parametric and modular design. The kinematic simulation experiment of parallel microplatform is realized by combining the motion trajectory of Simulink given microplatform. the results show that the deviation between the expected rod length and the actual rod length is 0.04mm and the error is 2.67%. 5. Motion trajectory control experiment of microplatform. Firstly, the experimental platform of parallel microplatform motion control based on fixed height motion controller is built. Secondly, through the point control mode and the state setting of each axis of the parallel microplatform control system, combined with the kinematic analysis of the microplatform, the motion control experiment of the planning trajectory of the microplatform is completed. Finally, the experimental results show that the motion sequence of the parallel microplatform is basically consistent with the planned trajectory, and the effectiveness of trajectory control for the parallel microplatform is verified.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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