面向人机协作的轻型柔顺机械臂结构设计与控制研究

发布时间：2018-07-29 17:21

【摘要】：传统的机器人多为刚性结构,在工作期间需要与外界环境进行隔离。随着科学技术的发展,工业机器人和服务机器人与外界环境之间的交互越来越多,使得机器人与外界环境的安全交互成为重大难题。为保证人与机器人的和谐安全相处,面向人机协作的机器人相继问世,机器人的轻量化和柔顺化成为一个重要的发展趋势。在机器人本体中,机械臂是其与外界环境频繁接触的重要部位,因此机械臂的轻量化和柔顺化设计是实现人机交互安全性的重要途径。本文设计了一款3DOF的轻型柔顺机械臂,通过选用轻质材料和结构优化的方法实现轻量化,引入弹性元件实现柔顺化,利用柔顺控制方案,实现机械臂与外界环境的柔顺安全交互。本文的主要研究内容如下:模仿人体手臂结构和尺寸,设计了一款3DOF的仿人机械臂,基于线性弹簧设计了串联弹性驱动器SEA,实现机械臂关节的柔顺性;通过选用合适材料和零件的结构优化,实现轻量化;并对弹性元件进行设计。对仿人机械臂进行了特性分析:建立了机械臂的运动学模型,计算了运动学的正逆解、雅可比矩阵和工作空间;建立动力学模型,求解了机械臂各关节的等效作用力矩。搭建机械臂的控制系统,完成了对控制系统硬件的选型。利用上位机对驱动舵机的位置PI和速度PI进行了设置,并对压力传感器和MTI位姿传感器进行校正,提出了一种MTI位置修正的方法。模仿太极推平圆运动,规划了机械臂的末端运动轨迹,完成了在末端自由状态下的位置跟随性实验,实验结果表明,机械臂在末端自由状态下具有较好的运动稳定性和位置跟随性,验证了机械臂设计的合理性;设计了基于末端力的主动避障算法,实现了机械臂对任意障碍的柔顺避障实验,结果表明,机械臂能稳定的躲避曲面形障碍,并能较好的恢复到规划轨迹上,验证了机械臂的柔顺性和安全性,证明了本文设计的柔顺机械臂具有与外界环境的柔顺交互能力和适应能力。
[Abstract]:Traditional robots are rigid structures and need to be isolated from the outside environment during work. With the development of science and technology, there are more and more interactions between industrial robots and service robots and the outside environment, which makes the safe interaction between the robot and the outside environment become a major problem. In order to guarantee the harmonious and safe coexistence between the robot and the robot, the robot for man-machine cooperation has come out one after another, and the lightweight and flexibility of the robot has become an important development trend. In the robot body, the robot arm is an important part of its frequent contact with the outside environment, so the lightweight and compliant design of the robot arm is an important way to achieve the safety of human-computer interaction. In this paper, a lightweight 3DOF compliant manipulator is designed. The lightweight material and structure optimization method is used to realize the lightweight, the elastic element is introduced to achieve compliance, and the compliant control scheme is used. The robot arm and the external environment are interacted smoothly and safely. The main contents of this paper are as follows: simulating the structure and size of human arm, a 3DOF humanoid manipulator is designed. Based on the linear spring, a series elastic actuator, SEAA, is designed to achieve the flexibility of the manipulator joint. The light weight is realized by selecting suitable materials and parts, and the elastic elements are designed. The characteristics of the humanoid manipulator are analyzed: the kinematics model of the manipulator is established, the forward and inverse solutions of kinematics, Jacobian matrix and workspace are calculated, and the dynamic model is established to solve the equivalent moment of action of each joint of the manipulator. Build the control system of the manipulator and complete the hardware selection of the control system. The position Pi and velocity Pi of the driving steering gear are set up by the upper computer, and the pressure sensor and the MTI position and pose sensor are corrected, and a method of MTI position correction is proposed. The trajectory of the end motion of the manipulator is planned by imitating the motion of the Taiji push-flat circle, and the position following experiment under the free state of the end is completed. The experimental results show that, The robot arm has better motion stability and position following in the free end state, which verifies the rationality of the design of the manipulator, designs an active obstacle avoidance algorithm based on the terminal force, and realizes the experiment of the robot arm's compliance with any obstacle. The results show that the robot arm can avoid the curved surface obstacle stably, and can recover to the planning track well, which verifies the flexibility and safety of the robot arm. It is proved that the designed compliant manipulator has the flexibility interaction ability and adaptability with the outside environment.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP242

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