轻型无线化人机协作机械臂的研究

发布时间：2018-07-26 08:20

【摘要】：多轴机器人系统正逐步替代人工从事沉重乏味的包装、运输、搬运等重复性作业,具有极其重要的作用。传统的机械臂内部电缆线繁多、不具备力感知功能,导致机械臂的可靠性、安全性和可维护性极差,传统的多轴机器人在空间、战场、家庭等有着特殊任务要求的场合难以胜任,协作型机械臂正是基于这些特殊任务要求而产生的。本文开展了轻型无线化人机协作机械臂的研究,大大减少了机械臂的内部走线并使之具备柔顺控制能力,能与人协同完成作业任务。针对复杂人机协同作业任务要求,详细分析了机械臂各项技术指标要求,在此基础上,提出轻型无线化人机协作机械臂的总体方案。机械臂关节采用永磁直流无刷电机作为动力,谐波减速器作为传动部件,并设计了失电制动器以在掉电状态下将关节抱死。关节内部安装有霍尔传感器、增量式编码器和绝对式编码器用于关节的位置和速度测量,同时在硬件电路上集成电流传感器,测量电机的电流换算成力矩。机械臂的控制部分包括顶层的中央控制器以及底层的关节伺服控制器,将机械臂在MATLAB和ADMAS中的运动学、动力学算法移植到中央控制器,关节伺服控制器实现关节的位置、速度和电流三环控制。关节伺服控制器采用FPGA+ARM的双处理器架构,具有冗余备份功能。机械臂中央控制器与关节伺服控制器之间通过ZIGBEE无线方式进行通讯,极大减少了关节内部走线的数量,提高了装配和调试的效率,更方便后续的维护。对设计的两类模块化关节进行加工和装配,并将开发的关节伺服控制器集成到关节内部,完成了传感器的采样处理、控制算法的调试、关节之间的无线通讯。并在此基础上进行关节性能指标的测试,包括三环跟踪实验、关节刚度和阻力实验、负载实验,最后对电流和力矩的对应关系进行了标定,实验表明研制的两类模块化关节达到了要求的技术指标。最后将七个模块化关节、臂杆、基座进行整体装配,中央控制器通过ZIGBEE下发七关节的角度指令信息,驱动整个机械臂运动,完成功能演示实验。
[Abstract]:Multi-axis robot system is gradually replacing manual to do heavy and tedious packaging, transportation, handling and other repetitive operations, which plays an extremely important role. There are many cable lines in the traditional robot arm, which does not have the function of force sensing, which leads to the poor reliability, safety and maintainability of the manipulator. The traditional multi-axis robot is in space and battlefield. The family is incompetent in situations with special task requirements, and cooperative manipulator is based on these special task requirements. In this paper, the research of the lightweight wireless man-machine cooperative manipulator is carried out, which greatly reduces the internal wiring of the manipulator and makes it have the ability of compliant control, and it can accomplish the task in cooperation with people. According to the task requirements of complex man-machine cooperative operation, the technical requirements of the manipulator are analyzed in detail. On the basis of this, the overall scheme of the lightweight wireless man-machine cooperative manipulator is proposed. The permanent magnet brushless DC motor is used as the power and the harmonic reducer is used as the transmission component in the joint of the mechanical arm, and a power loss brake is designed to lock the joint under the condition of power-off. Hall sensors are installed inside the joints, incremental encoders and absolute encoders are used to measure the position and velocity of joints, and current sensors are integrated on the hardware circuit to measure the current conversion of the motor into torque. The control part of the manipulator includes the central controller of the top layer and the joint servo controller of the bottom layer. The kinematics and dynamics algorithms of the manipulator in MATLAB and ADMAS are transplanted to the central controller, and the joint servo controller realizes the position of the joint. Speed and current three-loop control. The joint servo controller adopts the dual processor architecture of FPGA ARM and has redundant backup function. The communication between the central controller of the manipulator and the joint servo controller is carried out by ZIGBEE wireless mode, which greatly reduces the number of internal wiring of the joint, improves the efficiency of assembly and debugging, and facilitates the subsequent maintenance. Two kinds of modular joints are processed and assembled, and the developed joint servo controller is integrated into the joint interior. The sensor sampling processing, control algorithm debugging and wireless communication between joints are completed. On this basis, the joint performance indexes are tested, including three-ring tracking experiment, joint stiffness and resistance test, load test, and the corresponding relationship between current and torque is calibrated. The experimental results show that the two kinds of modular joints have met the required technical specifications. Finally, the seven modular joints, arm rods and pedestal are assembled as a whole, and the central controller sends out the angle instruction information of the seven joints through ZIGBEE to drive the whole manipulator motion and complete the function demonstration experiment.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP241

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